selftests/bpf: Extend uprobe/uretprobe triggering benchmarks

Settle on three "flavors" of uprobe/uretprobe, installed on different
kinds of instruction: nop, push, and ret. All three are testing
different internal code paths emulating or single-stepping instructions,
so are interesting to compare and benchmark separately.

To ensure `push rbp` instruction we ensure that uprobe_target_push() is
not a leaf function by calling (global __weak) noop function and
returning something afterwards (if we don't do that, compiler will just
do a tail call optimization).

Also, we need to make sure that compiler isn't skipping frame pointer
generation, so let's add `-fno-omit-frame-pointers` to Makefile.

Just to give an idea of where we currently stand in terms of relative
performance of different uprobe/uretprobe cases vs a cheap syscall
(getpgid()) baseline, here are results from my local machine:

$ benchs/run_bench_uprobes.sh
base : 1.561 ± 0.020M/s
uprobe-nop : 0.947 ± 0.007M/s
uprobe-push : 0.951 ± 0.004M/s
uprobe-ret : 0.443 ± 0.007M/s
uretprobe-nop : 0.471 ± 0.013M/s
uretprobe-push : 0.483 ± 0.004M/s
uretprobe-ret : 0.306 ± 0.007M/s

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240301214551.1686095-1-andrii@kernel.org

selftests/bpf: Test case for lacking CFI stub functions.

Ensure struct_ops rejects the registration of struct_ops types without
proper CFI stub functions.

bpf_test_no_cfi.ko is a module that attempts to register a struct_ops type
called "bpf_test_no_cfi_ops" with cfi_stubs of NULL and non-NULL value.
The NULL one should fail, and the non-NULL one should succeed. The module
can only be loaded successfully if these registrations yield the expected
results.

Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Link: https://lore.kernel.org/r/20240222021105.1180475-3-thinker.li@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

selftests/bpf: Remove intermediate test files.

The test of linking process creates several intermediate files.
Remove them once the build is over.

This reduces the number of files in selftests/bpf/ directory
from ~4400 to ~2600.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240220231102.49090-1-alexei.starovoitov@gmail.com

selftests/bpf: Remove empty TEST_CUSTOM_PROGS

Commit f04a32b2c5b5 ("selftests/bpf: Do not use sign-file as testcase")
removed the TEST_CUSTOM_PROGS assignment, and removed it from being used
on TEST_GEN_FILES. Remove two leftovers from that cleanup. Found by
inspection.

Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexey Gladkov <legion@kernel.org>
Link: https://lore.kernel.org/bpf/20240216-bpf-selftests-custom-progs-v1-1-f7cf281a1fda@suse.com

bpf: Move -Wno-compare-distinct-pointer-types to BPF_CFLAGS

Clang supports enabling/disabling certain conversion diagnostics via
the -W[no-]compare-distinct-pointer-types command line options.
Disabling this warning is required by some BPF selftests due to
-Werror. Until very recently GCC would emit these warnings
unconditionally, which was a problem for gcc-bpf, but we added support
for the command-line options to GCC upstream [1].

This patch moves the -Wno-cmopare-distinct-pointer-types from
CLANG_CFLAGS to BPF_CFLAGS in selftests/bpf/Makefile so the option
is also used in gcc-bpf builds, not just in clang builds.

Tested in bpf-next master.
No regressions.

[1] https://gcc.gnu.org/pipermail/gcc-patches/2023-August/627769.html

Signed-off-by: Jose E. Marchesi <jose.marchesi@oracle.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240130113624.24940-1-jose.marchesi@oracle.com

bpf: Build type-punning BPF selftests with -fno-strict-aliasing

A few BPF selftests perform type punning and they may break strict
aliasing rules, which are exploited by both GCC and clang by default
while optimizing. This can lead to broken compiled programs.

This patch disables strict aliasing for these particular tests, by
mean of the -fno-strict-aliasing command line option. This will make
sure these tests are optimized properly even if some strict aliasing
rule gets violated.

After this patch, GCC is able to build all the selftests without
warning about potential strict aliasing issue.

bpf@vger discussion on strict aliasing and BPF selftests:
https://lore.kernel.org/bpf/bae1205a-b6e5-4e46-8e20-520d7c327f7a@linux.dev/T/#t

Tested in bpf-next master.
No regressions.

Signed-off-by: Jose E. Marchesi <jose.marchesi@oracle.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/bae1205a-b6e5-4e46-8e20-520d7c327f7a@linux.dev
Link: https://lore.kernel.org/bpf/20240130110343.11217-1-jose.marchesi@oracle.com

bpf: Use -Wno-error in certain tests when building with GCC

Certain BPF selftests contain code that, albeit being legal C, trigger
warnings in GCC that cannot be disabled. This is the case for example
for the tests

progs/btf_dump_test_case_bitfields.c
progs/btf_dump_test_case_namespacing.c
progs/btf_dump_test_case_packing.c
progs/btf_dump_test_case_padding.c
progs/btf_dump_test_case_syntax.c

which contain struct type declarations inside function parameter
lists. This is problematic, because:

- The BPF selftests are built with -Werror.

- The Clang and GCC compilers sometimes differ when it comes to handle
warnings. in the handling of warnings. One compiler may emit
warnings for code that the other compiles compiles silently, and one
compiler may offer the possibility to disable certain warnings, while
the other doesn't.

In order to overcome this problem, this patch modifies the
tools/testing/selftests/bpf/Makefile in order to:

1. Enable the possibility of specifing per-source-file extra CFLAGS.
This is done by defining a make variable like:

<source-filename>-CFLAGS := <whateverflags>

And then modifying the proper Make rule in order to use these flags
when compiling <source-filename>.

2. Use the mechanism above to add -Wno-error to CFLAGS for the
following selftests:

progs/btf_dump_test_case_bitfields.c
progs/btf_dump_test_case_namespacing.c
progs/btf_dump_test_case_packing.c
progs/btf_dump_test_case_padding.c
progs/btf_dump_test_case_syntax.c

Note the corresponding -CFLAGS variables for these files are
defined only if the selftests are being built with GCC.

Note that, while compiler pragmas can generally be used to disable
particular warnings per file, this 1) is only possible for warning
that actually can be disabled in the command line, i.e. that have
-Wno-FOO options, and 2) doesn't apply to -Wno-error.

Tested in bpf-next master branch.
No regressions.

Signed-off-by: Jose E. Marchesi <jose.marchesi@oracle.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240127100702.21549-1-jose.marchesi@oracle.com

selftests/bpf: Attempt to build BPF programs with -Wsign-compare

GCC's -Wall includes -Wsign-compare while clang does not.
Since BPF programs are built with clang we need to add this flag explicitly
to catch problematic comparisons like:

int i = -1;
unsigned int j = 1;
if (i < j) // this is false.

long i = -1;
unsigned int j = 1;
if (i < j) // this is true.

C standard for reference:

- If either operand is unsigned long the other shall be converted to unsigned long.

- Otherwise, if one operand is a long int and the other unsigned int, then if a
long int can represent all the values of an unsigned int, the unsigned int
shall be converted to a long int; otherwise both operands shall be converted to
unsigned long int.

- Otherwise, if either operand is long, the other shall be converted to long.

- Otherwise, if either operand is unsigned, the other shall be converted to unsigned.

Unfortunately clang's -Wsign-compare is very noisy.
It complains about (s32)a == (u32)b which is safe and doen't have surprising behavior.

This patch fixes some of the issues. It needs a follow up to fix the rest.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/bpf/20231226191148.48536-2-alexei.starovoitov@gmail.com

selftests/bpf: Use pkg-config for libelf

When linking statically, libraries may require other dependencies to be
included to ld flags. In particular, libelf may require libzstd. Use
pkg-config to determine such dependencies.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20231125084253.85025-4-akihiko.odaki@daynix.com

selftests/bpf: Choose pkg-config for the target

pkg-config is used to build sign-file executable. It should use the
library for the target instead of the host as it is called during tests.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20231125084253.85025-2-akihiko.odaki@daynix.com

selftests/bpf: Add netlink helper library

Add a minimal netlink helper library for the BPF selftests. This has been
taken and cut down and cleaned up from iproute2. This covers basics such
as netdevice creation which we need for BPF selftests / BPF CI given
iproute2 package cannot cover it yet.

Stanislav Fomichev suggested that this could be replaced in future by ynl
tool generated C code once it has RTNL support to create devices. Once we
get to this point the BPF CI would also need to add libmnl. If no further
extensions are needed, a second option could be that we remove this code
again once iproute2 package has support.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20231024214904.29825-7-daniel@iogearbox.net
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

selftests/bpf: Support building selftests in optimized -O2 mode

Add support for building selftests with -O2 level of optimization, which
allows more compiler warnings detection (like lots of potentially
uninitialized usage), but also is useful to have a faster-running test
for some CPU-intensive tests.

One can build optimized versions of libbpf and selftests by running:

$ make RELEASE=1

There is a measurable speed up of about 10 seconds for me locally,
though it's mostly capped by non-parallelized serial tests. User CPU
time goes down by total 40 seconds, from 1m10s to 0m28s.

Unoptimized build (-O0)
=======================
Summary: 430/3544 PASSED, 25 SKIPPED, 4 FAILED

real 1m59.937s
user 1m10.877s
sys 3m14.880s

Optimized build (-O2)
=====================
Summary: 425/3543 PASSED, 25 SKIPPED, 9 FAILED

real 1m50.540s
user 0m28.406s
sys 3m13.198s

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20231006175744.3136675-2-andrii@kernel.org

selftests/bpf: Fix compiler warnings reported in -O2 mode

Fix a bunch of potentially unitialized variable usage warnings that are
reported by GCC in -O2 mode. Also silence overzealous stringop-truncation
class of warnings.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20231006175744.3136675-1-andrii@kernel.org

selftests/bpf: Add uprobe_multi to gen_tar target

The uprobe_multi program was not picked up for the gen_tar target. Fix
by adding it to TEST_GEN_FILES.

Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20231004122721.54525-4-bjorn@kernel.org

selftests/bpf: Enable lld usage for RISC-V

RISC-V has proper lld support. Use that, similar to what x86 does, for
urandom_read et al.

Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20231004122721.54525-3-bjorn@kernel.org

selftests/bpf: Add cross-build support for urandom_read et al

Some userland programs in the BPF test suite, e.g. urandom_read, is
missing cross-build support. Add cross-build support for these
programs

Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20231004122721.54525-2-bjorn@kernel.org

selftests/xsk: Iterate over all the sockets in the receive pkts function

Improve the receive_pkt() function to enable it to receive packets from
multiple sockets. Define a sock_num variable to iterate through all the
sockets in the Rx path. Add nb_valid_entries to check that all the
expected number of packets are received.

Revise the function __receive_pkts() to only inspect the receive ring
once, handle any received packets, and promptly return. Implement a bitmap
to store the value of number of sockets. Update Makefile to include
find_bit.c for compiling xskxceiver.

Signed-off-by: Tushar Vyavahare <tushar.vyavahare@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/bpf/20230927135241.2287547-5-tushar.vyavahare@intel.com

selftests/bpf: Add tests for symbol versioning for uprobe

This exercises the newly added dynsym symbol versioning logics.
Now we accept symbols in form of func, func@LIB_VERSION or
func@@LIB_VERSION.

The test rely on liburandom_read.so. For liburandom_read.so, we have:

$ nm -D liburandom_read.so
w __cxa_finalize@GLIBC_2.17
w __gmon_start__
w _ITM_deregisterTMCloneTable
w _ITM_registerTMCloneTable
0000000000000000 A LIBURANDOM_READ_1.0.0
0000000000000000 A LIBURANDOM_READ_2.0.0
000000000000081c T urandlib_api@@LIBURANDOM_READ_2.0.0
0000000000000814 T urandlib_api@LIBURANDOM_READ_1.0.0
0000000000000824 T urandlib_api_sameoffset@LIBURANDOM_READ_1.0.0
0000000000000824 T urandlib_api_sameoffset@@LIBURANDOM_READ_2.0.0
000000000000082c T urandlib_read_without_sema@@LIBURANDOM_READ_1.0.0
00000000000007c4 T urandlib_read_with_sema@@LIBURANDOM_READ_1.0.0
0000000000011018 D urandlib_read_with_sema_semaphore@@LIBURANDOM_READ_1.0.0

For `urandlib_api`, specifying `urandlib_api` will cause a conflict because
there are two symbols named urandlib_api and both are global bind.
For `urandlib_api_sameoffset`, there are also two symbols in the .so, but
both are at the same offset and essentially they refer to the same function
so no conflict.

Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20230918024813.237475-4-hengqi.chen@gmail.com

selftests/bpf: Include build flavors for install target

When using the "install" or targets depending on install, e.g. "gen_tar",
the BPF machine flavors weren't included.

A command like:
| make ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- O=/workspace/kbuild \
| HOSTCC=gcc FORMAT= SKIP_TARGETS="arm64 ia64 powerpc sparc64 x86 sgx" \
| -C tools/testing/selftests gen_tar
would not include bpf/no_alu32, bpf/cpuv4, or bpf/bpf-gcc.

Include the BPF machine flavors for "install" make target.

Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230831162954.111485-1-bjorn@kernel.org

selftests/bpf: Add uprobe_multi test program

Adding uprobe_multi test program that defines 50k uprobe_multi_func_*
functions and will serve as attach point for uprobe_multi bench test
in following patch.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230809083440.3209381-23-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

bpf: selftests: Add defrag selftests

These selftests tests 2 major scenarios: the BPF based defragmentation
can successfully be done and that packet pointers are invalidated after
calls to the kfunc. The logic is similar for both ipv4 and ipv6.

In the first scenario, we create a UDP client and UDP echo server. The
the server side is fairly straightforward: we attach the prog and simply
echo back the message.

The on the client side, we send fragmented packets to and expect the
reassembled message back from the server.

Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Link: https://lore.kernel.org/r/33e40fdfddf43be93f2cb259303f132f46750953.1689970773.git.dxu@dxuuu.xyz
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Enable test test_progs-cpuv4 for gcc build kernel

Currently, test_progs-cpuv4 is generated with clang build kernel
when bpf cpu=v4 is supported by the clang compiler.
Let us enable test_progs-cpuv4 for gcc build kernel as well.

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230728055745.2285202-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Add a cpuv4 test runner for cpu=v4 testing

Similar to no-alu32 runner, if clang compiler supports -mcpu=v4,
a cpuv4 runner is created to test bpf programs compiled with
-mcpu=v4.

The following are some num-of-insn statistics for each newer
instructions based on existing selftests, excluding subsequent
cpuv4 insn specific tests.

insn pattern # of instructions
reg = (s8)reg 4
reg = (s16)reg 4
reg = (s32)reg 144
reg = *(s8 *)(reg + off) 13
reg = *(s16 *)(reg + off) 14
reg = *(s32 *)(reg + off) 15215
reg = bswap16 reg 142
reg = bswap32 reg 38
reg = bswap64 reg 14
reg s/= reg 0
reg s%= reg 0
gotol <offset> 58

Note that in llvm -mcpu=v4 implementation, the compiler is a little
bit conservative about generating 'gotol' insn (32-bit branch offset)
as it didn't precise count the number of insns (e.g., some insns are
debug insns, etc.). Compared to old 'goto' insn, newer 'gotol' insn
should have comparable verification states to 'goto' insn.

With current patch set, all selftests passed with -mcpu=v4
when running test_progs-cpuv4 binary. The -mcpu=v3 and -mcpu=v2 run
are also successful.

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230728011250.3718252-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Add benchmark for bpf memory allocator

The benchmark could be used to compare the performance of hash map
operations and the memory usage between different flavors of bpf memory
allocator (e.g., no bpf ma vs bpf ma vs reuse-after-gp bpf ma). It also
could be used to check the performance improvement or the memory saving
provided by optimization.

The benchmark creates a non-preallocated hash map which uses bpf memory
allocator and shows the operation performance and the memory usage of
the hash map under different use cases:
(1) overwrite
Each CPU overwrites nonoverlapping part of hash map. When each CPU
completes overwriting of 64 elements in hash map, it increases the
op_count.
(2) batch_add_batch_del
Each CPU adds then deletes nonoverlapping part of hash map in batch.
When each CPU adds and deletes 64 elements in hash map, it increases
the op_count twice.
(3) add_del_on_diff_cpu
Each two-CPUs pair adds and deletes nonoverlapping part of map
cooperatively. When each CPU adds or deletes 64 elements in hash map,
it will increase the op_count.

The following is the benchmark results when comparing between different
flavors of bpf memory allocator. These tests are conducted on a KVM guest
with 8 CPUs and 16 GB memory. The command line below is used to do all
the following benchmarks:

./bench htab-mem --use-case $name ${OPTS} -w3 -d10 -a -p8

These results show that preallocated hash map has both better performance
and smaller memory footprint.

(1) non-preallocated + no bpf memory allocator (v6.0.19)
use kmalloc() + call_rcu

overwrite per-prod-op: 11.24 ± 0.07k/s, avg mem: 82.64 ± 26.32MiB, peak mem: 119.18MiB
batch_add_batch_del per-prod-op: 18.45 ± 0.10k/s, avg mem: 50.47 ± 14.51MiB, peak mem: 94.96MiB
add_del_on_diff_cpu per-prod-op: 14.50 ± 0.03k/s, avg mem: 4.64 ± 0.73MiB, peak mem: 7.20MiB

(2) preallocated
OPTS=--preallocated

overwrite per-prod-op: 191.42 ± 0.09k/s, avg mem: 1.24 ± 0.00MiB, peak mem: 1.49MiB
batch_add_batch_del per-prod-op: 221.83 ± 0.17k/s, avg mem: 1.23 ± 0.00MiB, peak mem: 1.49MiB
add_del_on_diff_cpu per-prod-op: 39.66 ± 0.31k/s, avg mem: 1.47 ± 0.13MiB, peak mem: 1.75MiB

(3) normal bpf memory allocator

overwrite per-prod-op: 126.59 ± 0.02k/s, avg mem: 2.26 ± 0.00MiB, peak mem: 2.74MiB
batch_add_batch_del per-prod-op: 83.37 ± 0.20k/s, avg mem: 2.14 ± 0.17MiB, peak mem: 2.74MiB
add_del_on_diff_cpu per-prod-op: 21.25 ± 0.24k/s, avg mem: 17.50 ± 3.32MiB, peak mem: 28.87MiB

Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20230704025039.938914-1-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Honor $(O) when figuring out paths

When building the kselftests out-of-tree, e.g. ...

| make ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- \
| O=/tmp/kselftest headers
| make ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- \
| O=/tmp/kselftest HOSTCC=gcc FORMAT= \
| SKIP_TARGETS="arm64 ia64 powerpc sparc64 x86 sgx" \
| -C tools/testing/selftests gen_tar

... the kselftest build would not pick up the correct GENDIR path, and
therefore not including autoconf.h.

Correct that by taking $(O) into consideration when figuring out the
GENDIR path.

Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230705113926.751791-3-bjorn@kernel.org

bpf: Replace deprecated -target with --target= for Clang

The -target option has been deprecated since clang 3.4 in 2013. Therefore, use
the preferred --target=bpf form instead. This also matches how we use --target=
in scripts/Makefile.clang.

Signed-off-by: Fangrui Song <maskray@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Quentin Monnet <quentin@isovalent.com>
Link: https://github.com/llvm/llvm-project/commit/274b6f0c87a6a1798de0a68135afc7f95def6277
Link: https://lore.kernel.org/bpf/20230624001856.1903733-1-maskray@google.com

selftests/bpf: Do not use sign-file as testcase

The sign-file utility (from scripts/) is used in prog_tests/verify_pkcs7_sig.c,
but the utility should not be called as a test. Executing this utility produces
the following error:

selftests: /linux/tools/testing/selftests/bpf: urandom_read
ok 16 selftests: /linux/tools/testing/selftests/bpf: urandom_read

selftests: /linux/tools/testing/selftests/bpf: sign-file
not ok 17 selftests: /linux/tools/testing/selftests/bpf: sign-file # exit=2

Also, urandom_read is mistakenly used as a test. It does not lead to an error,
but should be moved over to TEST_GEN_FILES as well. The empty TEST_CUSTOM_PROGS
can then be removed.

Fixes: fc97590668ae ("selftests/bpf: Add test for bpf_verify_pkcs7_signature() kfunc")
Signed-off-by: Alexey Gladkov <legion@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/ZEuWFk3QyML9y5QQ@example.org
Link: https://lore.kernel.org/bpf/88e3ab23029d726a2703adcf6af8356f7a2d3483.1684316821.git.legion@kernel.org

selftests/bpf: Fix pkg-config call building sign-file

When building sign-file, the call to get the CFLAGS for libcrypto is
missing white-space between `pkg-config` and `--cflags`:

$(shell $(HOSTPKG_CONFIG)--cflags libcrypto 2> /dev/null)

Removing the redirection of stderr, we see:

$ make -C tools/testing/selftests/bpf sign-file
make: Entering directory '[...]/tools/testing/selftests/bpf'
make: pkg-config--cflags: No such file or directory
SIGN-FILE sign-file
make: Leaving directory '[...]/tools/testing/selftests/bpf'

Add the missing space.

Fixes: fc97590668ae ("selftests/bpf: Add test for bpf_verify_pkcs7_signature() kfunc")
Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com>
Link: https://lore.kernel.org/bpf/20230426215032.415792-1-jeremy@azazel.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Remove stand-along test_verifier_log test binary

test_prog's prog_tests/verifier_log.c is superseding test_verifier_log
stand-alone test. It cover same checks and adds more, and is also
integrated into test_progs test runner.

Just remove test_verifier_log.c.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230412170655.1866831-1-andrii@kernel.org

selftests: xsk: Add xskxceiver.h dependency to Makefile

xskxceiver depends on xskxceiver.h so tell make about it.

Signed-off-by: Kal Conley <kal.conley@dectris.com>
Link: https://lore.kernel.org/r/20230403130151.31195-1-kal.conley@dectris.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

selftests/bpf: Add RESOLVE_BTFIDS dependency to bpf_testmod.ko

bpf_testmod.ko sometimes fails to build from a clean checkout:

BTF [M] linux/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.ko
/bin/sh: 1: linux-build//tools/build/resolve_btfids/resolve_btfids: not found

The reason is that RESOLVE_BTFIDS may not yet be built. Fix by adding a
dependency.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20230403172935.1553022-1-iii@linux.ibm.com

selftests/bpf: Unprivileged tests for test_loader.c

Extends test_loader.c:test_loader__run_subtests() by allowing to
execute tests in unprivileged mode, similar to test_verifier.c.

Adds the following new attributes controlling test_loader behavior:

__msg_unpriv
__success_unpriv
__failure_unpriv

* If any of these attributes is present the test would be loaded in
unprivileged mode.
* If only "privileged" attributes are present the test would be loaded
only in privileged mode.
* If both "privileged" and "unprivileged" attributes are present the
test would be loaded in both modes.
* If test has to be executed in both modes, __msg(text) is specified
and __msg_unpriv is not specified the behavior is the same as if
__msg_unpriv(text) is specified.
* For test filtering purposes the name of the program loaded in
unprivileged mode is derived from the usual program name by adding
`@unpriv' suffix.

Also adds attribute '__description'. This attribute specifies text to
be used instead of a program name for display and filtering purposes.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230325025524.144043-4-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Add --json-summary option to test_progs

Currently, test_progs outputs all stdout/stderr as it runs, and when it
is done, prints a summary.

It is non-trivial for tooling to parse that output and extract meaningful
information from it.

This change adds a new option, `--json-summary`/`-J` that let the caller
specify a file where `test_progs{,-no_alu32}` can write a summary of the
run in a json format that can later be parsed by tooling.

Currently, it creates a summary section with successes/skipped/failures
followed by a list of failed tests and subtests.

A test contains the following fields:
- name: the name of the test
- number: the number of the test
- message: the log message that was printed by the test.
- failed: A boolean indicating whether the test failed or not. Currently
we only output failed tests, but in the future, successful tests could
be added.
- subtests: A list of subtests associated with this test.

A subtest contains the following fields:
- name: same as above
- number: sanme as above
- message: the log message that was printed by the subtest.
- failed: same as above but for the subtest

An example run and json content below:
```
$ sudo ./test_progs -a $(grep -v '^#' ./DENYLIST.aarch64 | awk '{print
$1","}' | tr -d '\n') -j -J /tmp/test_progs.json
$ jq < /tmp/test_progs.json | head -n 30
{
"success": 29,
"success_subtest": 23,
"skipped": 3,
"failed": 28,
"results": [
{
"name": "bpf_cookie",
"number": 10,
"message": "test_bpf_cookie:PASS:skel_open 0 nsec\n",
"failed": true,
"subtests": [
{
"name": "multi_kprobe_link_api",
"number": 2,
"message": "kprobe_multi_link_api_subtest:PASS:load_kallsyms 0 nsec\nlibbpf: extern 'bpf_testmod_fentry_test1' (strong): not resolved\nlibbpf: failed to load object 'kprobe_multi'\nlibbpf: failed to load BPF skeleton 'kprobe_multi': -3\nkprobe_multi_link_api_subtest:FAIL:fentry_raw_skel_load unexpected error: -3\n",
"failed": true
},
{
"name": "multi_kprobe_attach_api",
"number": 3,
"message": "libbpf: extern 'bpf_testmod_fentry_test1' (strong): not resolved\nlibbpf: failed to load object 'kprobe_multi'\nlibbpf: failed to load BPF skeleton 'kprobe_multi': -3\nkprobe_multi_attach_api_subtest:FAIL:fentry_raw_skel_load unexpected error: -3\n",
"failed": true
},
{
"name": "lsm",
"number": 8,
"message": "lsm_subtest:PASS:lsm.link_create 0 nsec\nlsm_subtest:FAIL:stack_mprotect unexpected stack_mprotect: actual 0 != expected -1\n",
"failed": true
}
```

The file can then be used to print a summary of the test run and list of
failing tests/subtests:

```
$ jq -r < /tmp/test_progs.json '"Success: \(.success)/\(.success_subtest), Skipped: \(.skipped), Failed: \(.failed)"'

Success: 29/23, Skipped: 3, Failed: 28
$ jq -r < /tmp/test_progs.json '.results | map([
if .failed then "#\(.number) \(.name)" else empty end,
(
. as {name: $tname, number: $tnum} | .subtests | map(
if .failed then "#\($tnum)/\(.number) \($tname)/\(.name)" else empty end
)
)
]) | flatten | .[]' | head -n 20
#10 bpf_cookie
#10/2 bpf_cookie/multi_kprobe_link_api
#10/3 bpf_cookie/multi_kprobe_attach_api
#10/8 bpf_cookie/lsm
#15 bpf_mod_race
#15/1 bpf_mod_race/ksym (used_btfs UAF)
#15/2 bpf_mod_race/kfunc (kfunc_btf_tab UAF)
#36 cgroup_hierarchical_stats
#61 deny_namespace
#61/1 deny_namespace/unpriv_userns_create_no_bpf
#73 fexit_stress
#83 get_func_ip_test
#99 kfunc_dynptr_param
#99/1 kfunc_dynptr_param/dynptr_data_null
#99/4 kfunc_dynptr_param/dynptr_data_null
#100 kprobe_multi_bench_attach
#100/1 kprobe_multi_bench_attach/kernel
#100/2 kprobe_multi_bench_attach/modules
#101 kprobe_multi_test
#101/1 kprobe_multi_test/skel_api
```

Signed-off-by: Manu Bretelle <chantr4@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230317163256.3809328-1-chantr4@gmail.com

selftests/bpf: Add local-storage-create benchmark

This patch tests how many kmallocs is needed to create and free
a batch of UDP sockets and each socket has a 64bytes bpf storage.
It also measures how fast the UDP sockets can be created.

The result is from my qemu setup.

Before bpf_mem_cache_alloc/free:
./bench -p 1 local-storage-create
Setting up benchmark 'local-storage-create'...
Benchmark 'local-storage-create' started.
Iter 0 ( 73.193us): creates 213.552k/s (213.552k/prod), 3.09 kmallocs/create
Iter 1 (-20.724us): creates 211.908k/s (211.908k/prod), 3.09 kmallocs/create
Iter 2 ( 9.280us): creates 212.574k/s (212.574k/prod), 3.12 kmallocs/create
Iter 3 ( 11.039us): creates 213.209k/s (213.209k/prod), 3.12 kmallocs/create
Iter 4 (-11.411us): creates 213.351k/s (213.351k/prod), 3.12 kmallocs/create
Iter 5 ( -7.915us): creates 214.754k/s (214.754k/prod), 3.12 kmallocs/create
Iter 6 ( 11.317us): creates 210.942k/s (210.942k/prod), 3.12 kmallocs/create
Summary: creates 212.789 ± 1.310k/s (212.789k/prod), 3.12 kmallocs/create

After bpf_mem_cache_alloc/free:
./bench -p 1 local-storage-create
Setting up benchmark 'local-storage-create'...
Benchmark 'local-storage-create' started.
Iter 0 ( 68.265us): creates 243.984k/s (243.984k/prod), 1.04 kmallocs/create
Iter 1 ( 30.357us): creates 238.424k/s (238.424k/prod), 1.04 kmallocs/create
Iter 2 (-18.712us): creates 232.963k/s (232.963k/prod), 1.04 kmallocs/create
Iter 3 (-15.885us): creates 238.879k/s (238.879k/prod), 1.04 kmallocs/create
Iter 4 ( 5.590us): creates 237.490k/s (237.490k/prod), 1.04 kmallocs/create
Iter 5 ( 8.577us): creates 237.521k/s (237.521k/prod), 1.04 kmallocs/create
Iter 6 ( -6.263us): creates 238.508k/s (238.508k/prod), 1.04 kmallocs/create
Summary: creates 237.298 ± 2.198k/s (237.298k/prod), 1.04 kmallocs/create

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20230308065936.1550103-18-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: make BPF compiler flags stricter

We recently added -Wuninitialized, but it's not enough to catch various
silly mistakes or omissions. Let's go all the way to -Wall, just like we
do for user-space code.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230309054015.4068562-5-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Disassembler tests for verifier.c:convert_ctx_access()

Function verifier.c:convert_ctx_access() applies some rewrites to BPF
instructions that read or write BPF program context. This commit adds
machinery to allow test cases that inspect BPF program after these
rewrites are applied.

An example of a test case:

{
// Shorthand for field offset and size specification
N(CGROUP_SOCKOPT, struct bpf_sockopt, retval),

// Pattern generated for field read
.read = "$dst = *(u64 *)($ctx + bpf_sockopt_kern::current_task);"
"$dst = *(u64 *)($dst + task_struct::bpf_ctx);"
"$dst = *(u32 *)($dst + bpf_cg_run_ctx::retval);",

// Pattern generated for field write
.write = "*(u64 *)($ctx + bpf_sockopt_kern::tmp_reg) = r9;"
"r9 = *(u64 *)($ctx + bpf_sockopt_kern::current_task);"
"r9 = *(u64 *)(r9 + task_struct::bpf_ctx);"
"*(u32 *)(r9 + bpf_cg_run_ctx::retval) = $src;"
"r9 = *(u64 *)($ctx + bpf_sockopt_kern::tmp_reg);" ,
},

For each test case, up to three programs are created:
- One that uses BPF_LDX_MEM to read the context field.
- One that uses BPF_STX_MEM to write to the context field.
- One that uses BPF_ST_MEM to write to the context field.

The disassembly of each program is compared with the pattern specified
in the test case.

Kernel code for disassembly is reused (as is in the bpftool).
To keep Makefile changes to the minimum, symbolic links to
`kernel/bpf/disasm.c` and `kernel/bpf/disasm.h ` are added.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230304011247.566040-4-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Add -Wuninitialized flag to bpf prog flags

Per C99 standard [0], Section 6.7.8, Paragraph 10:

If an object that has automatic storage duration is not initialized
explicitly, its value is indeterminate.

And in the same document, in appendix "J.2 Undefined behavior":

The behavior is undefined in the following circumstances:
[...]
The value of an object with automatic storage duration is used while
it is indeterminate (6.2.4, 6.7.8, 6.8).

This means that use of an uninitialized stack variable is undefined
behavior, and therefore that clang can choose to do a variety of scary
things, such as not generating bytecode for "bunch of useful code" in
the below example:

void some_func()
{
int i;
if (!i)
return;
// bunch of useful code
}

To add insult to injury, if some_func above is a helper function for
some BPF program, clang can choose to not generate an "exit" insn,
causing verifier to fail with "last insn is not an exit or jmp". Going
from that verification failure to the root cause of uninitialized use
is certain to be frustrating.

This patch adds -Wuninitialized to the cflags for selftest BPF progs and
fixes up existing instances of uninitialized use.

[0]: https://www.open-std.org/jtc1/sc22/WG14/www/docs/n1256.pdf

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Cc: David Vernet <void@manifault.com>
Cc: Tejun Heo <tj@kernel.org>
Acked-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20230303005500.1614874-1-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Set __BITS_PER_LONG if target is bpf for LoongArch

If target is bpf, there is no __loongarch__ definition, __BITS_PER_LONG
defaults to 32, __NR_nanosleep is not defined:

#if defined(__ARCH_WANT_TIME32_SYSCALLS) || __BITS_PER_LONG != 32
#define __NR_nanosleep 101
__SC_3264(__NR_nanosleep, sys_nanosleep_time32, sys_nanosleep)
#endif

Work around this problem, by explicitly setting __BITS_PER_LONG to
__loongarch_grlen which is defined by compiler as 64 for LA64.

This is similar with commit 36e70b9b06bf ("selftests, bpf: Fix broken
riscv build").

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1677585781-21628-1-git-send-email-yangtiezhu@loongson.cn

selftest/bpf/benchs: Add benchmark for hashmap lookups

Add a new benchmark which measures hashmap lookup operations speed. A user can
control the following parameters of the benchmark:

* key_size (max 1024): the key size to use
* max_entries: the hashmap max entries
* nr_entries: the number of entries to insert/lookup
* nr_loops: the number of loops for the benchmark
* map_flags The hashmap flags passed to BPF_MAP_CREATE

The BPF program performing the benchmarks calls two nested bpf_loop:

bpf_loop(nr_loops/nr_entries)
bpf_loop(nr_entries)
bpf_map_lookup()

So the nr_loops determines the number of actual map lookups. All lookups are
successful.

Example (the output is generated on a AMD Ryzen 9 3950X machine):

for nr_entries in `seq 4096 4096 65536`; do echo -n "$((nr_entries*100/65536))% full: "; sudo ./bench -d2 -a bpf-hashmap-lookup --key_size=4 --nr_entries=$nr_entries --max_entries=65536 --nr_loops=1000000 --map_flags=0x40 | grep cpu; done
6% full: cpu01: lookup 50.739M ± 0.018M events/sec (approximated from 32 samples of ~19ms)
12% full: cpu01: lookup 47.751M ± 0.015M events/sec (approximated from 32 samples of ~20ms)
18% full: cpu01: lookup 45.153M ± 0.013M events/sec (approximated from 32 samples of ~22ms)
25% full: cpu01: lookup 43.826M ± 0.014M events/sec (approximated from 32 samples of ~22ms)
31% full: cpu01: lookup 41.971M ± 0.012M events/sec (approximated from 32 samples of ~23ms)
37% full: cpu01: lookup 41.034M ± 0.015M events/sec (approximated from 32 samples of ~24ms)
43% full: cpu01: lookup 39.946M ± 0.012M events/sec (approximated from 32 samples of ~25ms)
50% full: cpu01: lookup 38.256M ± 0.014M events/sec (approximated from 32 samples of ~26ms)
56% full: cpu01: lookup 36.580M ± 0.018M events/sec (approximated from 32 samples of ~27ms)
62% full: cpu01: lookup 36.252M ± 0.012M events/sec (approximated from 32 samples of ~27ms)
68% full: cpu01: lookup 35.200M ± 0.012M events/sec (approximated from 32 samples of ~28ms)
75% full: cpu01: lookup 34.061M ± 0.009M events/sec (approximated from 32 samples of ~29ms)
81% full: cpu01: lookup 34.374M ± 0.010M events/sec (approximated from 32 samples of ~29ms)
87% full: cpu01: lookup 33.244M ± 0.011M events/sec (approximated from 32 samples of ~30ms)
93% full: cpu01: lookup 32.182M ± 0.013M events/sec (approximated from 32 samples of ~31ms)
100% full: cpu01: lookup 31.497M ± 0.016M events/sec (approximated from 32 samples of ~31ms)

Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230213091519.1202813-8-aspsk@isovalent.com

selftests/bpf: Cross-compile bpftool

When the BPF selftests are cross-compiled, only the a host version of
bpftool is built. This version of bpftool is used on the host-side to
generate various intermediates, e.g., skeletons.

The test runners are also using bpftool, so the Makefile will symlink
bpftool from the selftest/bpf root, where the test runners will look
the tool:

| $(Q)ln -sf $(if $2,..,.)/tools/build/bpftool/bootstrap/bpftool \
| $(OUTPUT)/$(if $2,$2/)bpftool

There are two problems for cross-compilation builds:

1. There is no native (cross-compilation target) of bpftool
2. The bootstrap/bpftool is never cross-compiled (by design)

Make sure that a native/cross-compiled version of bpftool is built,
and if CROSS_COMPILE is set, symlink the native/non-bootstrap version.

Acked-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20230214161253.183458-1-bjorn@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Fix out-of-srctree build

Building BPF selftests out of srctree fails with:

make: *** No rule to make target '/linux-build//ima_setup.sh', needed by 'ima_setup.sh'. Stop.

The culprit is the rule that defines convenient shorthands like
"make test_progs", which builds $(OUTPUT)/test_progs. These shorthands
make sense only for binaries that are built though; scripts that live
in the source tree do not end up in $(OUTPUT).

Therefore drop $(TEST_PROGS) and $(TEST_PROGS_EXTENDED) from the rule.

The issue exists for a while, but it became a problem only after commit
d68ae4982cb7 ("selftests/bpf: Install all required files to run selftests"),
which added dependencies on these scripts.

Fixes: 03dcb78460c2 ("selftests/bpf: Add simple per-test targets to Makefile")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230208231211.283606-1-iii@linux.ibm.com

selftests/bpf: Forward SAN_CFLAGS and SAN_LDFLAGS to runqslower and libbpf

To get useful results from the Memory Sanitizer, all code running in a
process needs to be instrumented. When building tests with other
sanitizers, it's not strictly necessary, but is also helpful.
So make sure runqslower and libbpf are compiled with SAN_CFLAGS and
linked with SAN_LDFLAGS.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230210001210.395194-5-iii@linux.ibm.com

selftests/bpf: Split SAN_CFLAGS and SAN_LDFLAGS

Memory Sanitizer requires passing different options to CFLAGS and
LDFLAGS: besides the mandatory -fsanitize=memory, one needs to pass
header and library paths, and passing -L to a compilation step
triggers -Wunused-command-line-argument. So introduce a separate
variable for linker flags. Use $(SAN_CFLAGS) as a default in order to
avoid complicating the ASan usage.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230210001210.395194-4-iii@linux.ibm.com

selftests/bpf: Quote host tools

Using HOSTCC="ccache clang" breaks building the tests, since, when it's
forwarded to e.g. bpftool, the child make sees HOSTCC=ccache and
"clang" is considered a target. Fix by quoting it, and also HOSTLD and
HOSTAR for consistency.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230210001210.395194-2-iii@linux.ibm.com

selftests/bpf: introduce XDP compliance test tool

Introduce xdp_features tool in order to test XDP features supported by
the NIC and match them against advertised ones.
In order to test supported/advertised XDP features, xdp_features must
run on the Device Under Test (DUT) and on a Tester device.
xdp_features opens a control TCP channel between DUT and Tester devices
to send control commands from Tester to the DUT and a UDP data channel
where the Tester sends UDP 'echo' packets and the DUT is expected to
reply back with the same packet. DUT installs multiple XDP programs on the
NIC to test XDP capabilities and reports back to the Tester some XDP stats.
Currently xdp_features supports the following XDP features:
- XDP_DROP
- XDP_ABORTED
- XDP_PASS
- XDP_TX
- XDP_REDIRECT
- XDP_NDO_XMIT

Co-developed-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/7c1af8e7e6ef0614cf32fa9e6bdaa2d8d605f859.1675245258.git.lorenzo@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Fix symlink creation error

When building with O=, the following error occurs:

ln: failed to create symbolic link 'no_alu32/bpftool': No such file or directory

Adjust the code to account for $(OUTPUT).

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/r/20230128000650.1516334-6-iii@linux.ibm.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Fix liburandom_read.so linker error

When building with O=, the following linker error occurs:

clang: error: no such file or directory: 'liburandom_read.so'

Fix by adding $(OUTPUT) to the linker search path.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/r/20230128000650.1516334-5-iii@linux.ibm.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Fix vmtest static compilation error

As stated in README.rst, in order to resolve errors with linker errors,
'LDLIBS=-static' should be used. Most problems will be solved by this
option, but in the case of urandom_read, this won't fix the problem. So
the Makefile is currently implemented to strip the 'static' option when
compiling the urandom_read. However, stripping this static option isn't
configured properly on $(LDLIBS) correctly, which is now causing errors
on static compilation.

# LDLIBS=-static ./vmtest.sh
ld.lld: error: attempted static link of dynamic object liburandom_read.so
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [Makefile:190: /linux/tools/testing/selftests/bpf/urandom_read] Error 1
make: *** Waiting for unfinished jobs....

This commit fixes this problem by configuring the strip with $(LDLIBS).

Fixes: 68084a136420 ("selftests/bpf: Fix building bpf selftests statically")
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230125100440.21734-1-danieltimlee@gmail.com

selftests/bpf: Simple program to dump XDP RX metadata

To be used for verification of driver implementations. Note that
the skb path is gone from the series, but I'm still keeping the
implementation for any possible future work.

$ xdp_hw_metadata <ifname>

On the other machine:

$ echo -n xdp | nc -u -q1 <target> 9091 # for AF_XDP
$ echo -n skb | nc -u -q1 <target> 9092 # for skb

Sample output:

# xdp
xsk_ring_cons__peek: 1
0x19f9090: rx_desc[0]->addr=100000000008000 addr=8100 comp_addr=8000
rx_timestamp_supported: 1
rx_timestamp: 1667850075063948829
0x19f9090: complete idx=8 addr=8000

# skb
found skb hwtstamp = 1668314052.854274681

Decoding:
# xdp
rx_timestamp=1667850075.063948829

$ date -d @1667850075
Mon Nov 7 11:41:15 AM PST 2022
$ date
Mon Nov 7 11:42:05 AM PST 2022

# skb
$ date -d @1668314052
Sat Nov 12 08:34:12 PM PST 2022
$ date
Sat Nov 12 08:37:06 PM PST 2022

Cc: John Fastabend <john.fastabend@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Anatoly Burakov <anatoly.burakov@intel.com>
Cc: Alexander Lobakin <alexandr.lobakin@intel.com>
Cc: Magnus Karlsson <magnus.karlsson@gmail.com>
Cc: Maryam Tahhan <mtahhan@redhat.com>
Cc: xdp-hints@xdp-project.net
Cc: netdev@vger.kernel.org
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20230119221536.3349901-18-sdf@google.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

selftests/bpf: Verify xdp_metadata xdp->af_xdp path

- create new netns
- create veth pair (veTX+veRX)
- setup AF_XDP socket for both interfaces
- attach bpf to veRX
- send packet via veTX
- verify the packet has expected metadata at veRX

Cc: John Fastabend <john.fastabend@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Anatoly Burakov <anatoly.burakov@intel.com>
Cc: Alexander Lobakin <alexandr.lobakin@intel.com>
Cc: Magnus Karlsson <magnus.karlsson@gmail.com>
Cc: Maryam Tahhan <mtahhan@redhat.com>
Cc: xdp-hints@xdp-project.net
Cc: netdev@vger.kernel.org
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20230119221536.3349901-12-sdf@google.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

selftests/xsk: get rid of built-in XDP program

Get rid of the built-in XDP program that was part of the old libbpf
code in xsk.c and replace it with an eBPF program build using the
framework by all the other bpf selftests. This will form the base for
adding more programs in later commits.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20230111093526.11682-12-magnus.karlsson@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

bpf: makefiles: Do not generate empty vmlinux.h

Remove the empty vmlinux.h if bpftool failed to dump btf info.
The empty vmlinux.h can hide real error when reading output
of make.

This is done by adding .DELETE_ON_ERROR special target in related
makefiles.

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20221217223509.88254-3-changbin.du@gmail.com

selftests/bpf: add generic BPF program tester-loader

It's become a common pattern to have a collection of small BPF programs
in one BPF object file, each representing one test case. On user-space
side of such tests we maintain a table of program names and expected
failure or success, along with optional expected verifier log message.

This works, but each set of tests reimplement this mundane code over and
over again, which is a waste of time for anyone trying to add a new set
of tests. Furthermore, it's quite error prone as it's way too easy to miss
some entries in these manually maintained test tables (as evidences by
dynptr_fail tests, in which ringbuf_release_uninit_dynptr subtest was
accidentally missed; this is fixed in next patch).

So this patch implements generic test_loader, which accepts skeleton
name and handles the rest of details: opens and loads BPF object file,
making sure each program is tested in isolation. Optionally each test
case can specify expected BPF verifier log message. In case of failure,
tester makes sure to report verifier log, but it also reports verifier
log in verbose mode unconditionally.

Now, the interesting deviation from existing custom implementations is
the use of btf_decl_tag attribute to specify expected-to-fail vs
expected-to-succeed markers and, optionally, expected log message
directly next to BPF program source code, eliminating the need to
manually create and update table of tests.

We define few macros wrapping btf_decl_tag with a convention that all
values of btf_decl_tag start with "comment:" prefix, and then utilizing
a very simple "just_some_text_tag" or "some_key_name=<value>" pattern to
define things like expected success/failure, expected verifier message,
extra verifier log level (if necessary). This approach is demonstrated
by next patch in which two existing sets of failure tests are converted.

Tester supports both expected-to-fail and expected-to-succeed programs,
though this patch set didn't convert any existing expected-to-succeed
programs yet, as existing tests couple BPF program loading with their
further execution through attach or test_prog_run. One way to allow
testing scenarios like this would be ability to specify custom callback,
executed for each successfully loaded BPF program. This is left for
follow up patches, after some more analysis of existing test cases.

This test_loader is, hopefully, a start of a test_verifier-like runner,
but integrated into test_progs infrastructure. It will allow much better
"user experience" of defining low-level verification tests that can take
advantage of all the libbpf-provided nicety features on BPF side: global
variables, declarative maps, etc. All while having a choice of defining
it in C or as BPF assembly (through __attribute__((naked)) functions and
using embedded asm), depending on what makes most sense in each
particular case. This will be explored in follow up patches as well.

Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221207201648.2990661-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Install all required files to run selftests

When installing the selftests using
"make -C tools/testing/selftests install", we need to make sure
all the required files to run the selftests are installed. Let's
make sure this is the case.

Signed-off-by: Daan De Meyer <daan.j.demeyer@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221205131618.1524337-2-daan.j.demeyer@gmail.com

selftests/bpf: Pass target triple to get_sys_includes macro

When cross-compiling [1], the get_sys_includes make macro should use
the target system include path, and not the build hosts system include
path.

Make clang honor the CROSS_COMPILE triple.

[1] e.g. "ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- make"

Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Anders Roxell <anders.roxell@linaro.org>
Link: https://lore.kernel.org/bpf/20221115182051.582962-2-bjorn@kernel.org

selftests/bpf: Explicitly pass RESOLVE_BTFIDS to sub-make

When cross-compiling selftests/bpf, the resolve_btfids binary end up
in a different directory, than the regular resolve_btfids
builds. Populate RESOLVE_BTFIDS for sub-make, so it can find the
binary.

Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20221115182051.582962-1-bjorn@kernel.org

selftests/bpf: Use consistent build-id type for liburandom_read.so

lld produces "fast" style build-ids by default, which is inconsistent
with ld's "sha1" style. Explicitly specify build-id style to be "sha1"
when linking liburandom_read.so the same way it is already done for
urandom_read.

Signed-off-by: Artem Savkov <asavkov@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: KP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/bpf/20221104094016.102049-1-asavkov@redhat.com

selftests/bpf: Add test verifying bpf_ringbuf_reserve retval use in map ops

Add a test_ringbuf_map_key test prog, borrowing heavily from extant
test_ringbuf.c. The program tries to use the result of
bpf_ringbuf_reserve as map_key, which was not possible before previouis
commits in this series. The test runner added to prog_tests/ringbuf.c
verifies that the program loads and does basic sanity checks to confirm
that it runs as expected.

Also, refactor test_ringbuf such that runners for existing test_ringbuf
and newly-added test_ringbuf_map_key are subtests of 'ringbuf' top-level
test.

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221020160721.4030492-3-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Add liburandom_read.so to TEST_GEN_FILES

Added urandom_read shared lib is missing from the list of installed
files what makes urandom_read test after `make install` or `make
gen_tar` broken.

Add the library to TEST_GEN_FILES. The names in the list do not
contain $(OUTPUT) since it's added by lib.mk code.

Fixes: 00a0fa2d7d49 ("selftests/bpf: Add urandom_read shared lib and USDTs")
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220920161409.129953-1-ykaliuta@redhat.com

selftests/bpf: Add test for bpf_verify_pkcs7_signature() kfunc

Perform several tests to ensure the correct implementation of the
bpf_verify_pkcs7_signature() kfunc.

Do the tests with data signed with a generated testing key (by using
sign-file from scripts/) and with the tcp_bic.ko kernel module if it is
found in the system. The test does not fail if tcp_bic.ko is not found.

First, perform an unsuccessful signature verification without data.

Second, perform a successful signature verification with the session
keyring and a new one created for testing.

Then, ensure that permission and validation checks are done properly on the
keyring provided to bpf_verify_pkcs7_signature(), despite those checks were
deferred at the time the keyring was retrieved with bpf_lookup_user_key().
The tests expect to encounter an error if the Search permission is removed
from the keyring, or the keyring is expired.

Finally, perform a successful and unsuccessful signature verification with
the keyrings with pre-determined IDs (the last test fails because the key
is not in the platform keyring).

The test is currently in the deny list for s390x (JIT does not support
calling kernel function).

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Link: https://lore.kernel.org/r/20220920075951.929132-13-roberto.sassu@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Add veristat tool for mass-verifying BPF object files

Add a small tool, veristat, that allows mass-verification of
a set of *libbpf-compatible* BPF ELF object files. For each such object
file, veristat will attempt to verify each BPF program *individually*.
Regardless of success or failure, it parses BPF verifier stats and
outputs them in human-readable table format. In the future we can also
add CSV and JSON output for more scriptable post-processing, if necessary.

veristat allows to specify a set of stats that should be output and
ordering between multiple objects and files (e.g., so that one can
easily order by total instructions processed, instead of default file
name, prog name, verdict, total instructions order).

This tool should be useful for validating various BPF verifier changes
or even validating different kernel versions for regressions.

Here's an example for some of the heaviest selftests/bpf BPF object
files:

$ sudo ./veristat -s insns,file,prog {pyperf,loop,test_verif_scale,strobemeta,test_cls_redirect,profiler}*.linked3.o
File Program Verdict Duration, us Total insns Total states Peak states
------------------------------------ ------------------------------------ ------- ------------ ----------- ------------ -----------
loop3.linked3.o while_true failure 350990 1000001 9663 9663
test_verif_scale3.linked3.o balancer_ingress success 115244 845499 8636 2141
test_verif_scale2.linked3.o balancer_ingress success 77688 773445 3048 788
pyperf600.linked3.o on_event success 2079872 624585 30335 30241
pyperf600_nounroll.linked3.o on_event success 353972 568128 37101 2115
strobemeta.linked3.o on_event success 455230 557149 15915 13537
test_verif_scale1.linked3.o balancer_ingress success 89880 554754 8636 2141
strobemeta_nounroll2.linked3.o on_event success 433906 501725 17087 1912
loop6.linked3.o trace_virtqueue_add_sgs success 282205 398057 8717 919
loop1.linked3.o nested_loops success 125630 361349 5504 5504
pyperf180.linked3.o on_event success 2511740 160398 11470 11446
pyperf100.linked3.o on_event success 744329 87681 6213 6191
test_cls_redirect.linked3.o cls_redirect success 54087 78925 4782 903
strobemeta_subprogs.linked3.o on_event success 57898 65420 1954 403
test_cls_redirect_subprogs.linked3.o cls_redirect success 54522 64965 4619 958
strobemeta_nounroll1.linked3.o on_event success 43313 57240 1757 382
pyperf50.linked3.o on_event success 194355 46378 3263 3241
profiler2.linked3.o tracepoint__syscalls__sys_enter_kill success 23869 43372 1423 542
pyperf_subprogs.linked3.o on_event success 29179 36358 2499 2499
profiler1.linked3.o tracepoint__syscalls__sys_enter_kill success 13052 27036 1946 936
profiler3.linked3.o tracepoint__syscalls__sys_enter_kill success 21023 26016 2186 915
profiler2.linked3.o kprobe__vfs_link success 5255 13896 303 271
profiler1.linked3.o kprobe__vfs_link success 7792 12687 1042 1041
profiler3.linked3.o kprobe__vfs_link success 7332 10601 865 865
profiler2.linked3.o kprobe_ret__do_filp_open success 3417 8900 216 199
profiler2.linked3.o kprobe__vfs_symlink success 3548 8775 203 186
pyperf_global.linked3.o on_event success 10007 7563 520 520
profiler3.linked3.o kprobe_ret__do_filp_open success 4708 6464 532 532
profiler1.linked3.o kprobe_ret__do_filp_open success 3090 6445 508 508
profiler3.linked3.o kprobe__vfs_symlink success 4477 6358 521 521
profiler1.linked3.o kprobe__vfs_symlink success 3381 6347 507 507
profiler2.linked3.o raw_tracepoint__sched_process_exec success 2464 5874 292 189
profiler3.linked3.o raw_tracepoint__sched_process_exec success 2677 4363 397 283
profiler2.linked3.o kprobe__proc_sys_write success 1800 4355 143 138
profiler1.linked3.o raw_tracepoint__sched_process_exec success 1649 4019 333 240
pyperf600_bpf_loop.linked3.o on_event success 2711 3966 306 306
profiler2.linked3.o raw_tracepoint__sched_process_exit success 1234 3138 83 66
profiler3.linked3.o kprobe__proc_sys_write success 1755 2623 223 223
profiler1.linked3.o kprobe__proc_sys_write success 1222 2456 193 193
loop2.linked3.o while_true success 608 1783 57 30
profiler3.linked3.o raw_tracepoint__sched_process_exit success 789 1680 146 146
profiler1.linked3.o raw_tracepoint__sched_process_exit success 592 1526 133 133
strobemeta_bpf_loop.linked3.o on_event success 1015 1512 106 106
loop4.linked3.o combinations success 165 524 18 17
profiler3.linked3.o raw_tracepoint__sched_process_fork success 196 299 25 25
profiler1.linked3.o raw_tracepoint__sched_process_fork success 109 265 19 19
profiler2.linked3.o raw_tracepoint__sched_process_fork success 111 265 19 19
loop5.linked3.o while_true success 47 84 9 9
------------------------------------ ------------------------------------ ------- ------------ ----------- ------------ -----------

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220909193053.577111-4-andrii@kernel.org

selftests/bpf: regroup and declare similar kfuncs selftests in an array

Similar to tools/testing/selftests/bpf/prog_tests/dynptr.c:
we declare an array of tests that we run one by one in a for loop.

Followup patches will add more similar-ish tests, so avoid a lot of copy
paste by grouping the declaration in an array.

For light skeletons, we have to rely on the offsetof() macro so we can
statically declare which program we are using.
In the libbpf case, we can rely on bpf_object__find_program_by_name().
So also change the Makefile to generate both light skeletons and normal
ones.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20220906151303.2780789-2-benjamin.tissoires@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Store BPF object files with .bpf.o extension

BPF object files are, in a way, the final artifact produced as part of
the ahead-of-time compilation process. That makes them somewhat special
compared to "regular" object files, which are a intermediate build
artifacts that can typically be removed safely. As such, it can make
sense to name them differently to make it easier to spot this difference
at a glance.

Among others, libbpf-bootstrap [0] has established the extension .bpf.o
for BPF object files. It seems reasonable to follow this example and
establish the same denomination for selftest build artifacts. To that
end, this change adjusts the corresponding part of the build system and
the test programs loading BPF object files to work with .bpf.o files.

[0] https://github.com/libbpf/libbpf-bootstrap

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Müller <deso@posteo.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220901222253.1199242-1-deso@posteo.net

selftests/bpf: Make sure bpf_{g,s}et_retval is exposed everywhere

For each hook, have a simple bpf_set_retval(bpf_get_retval) program
and make sure it loads for the hooks we want. The exceptions are
the hooks which don't propagate the error to the callers:

- sockops
- recvmsg
- getpeername
- getsockname
- cg_skb ingress and egress

Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20220823222555.523590-6-sdf@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests, xsk: Rename AF_XDP testing app

Recently, xsk part of libbpf was moved to selftests/bpf directory and
lives on its own because there is an AF_XDP testing application that
needs it called xdpxceiver. That name makes it a bit hard to indicate
who maintains it as there are other XDP samples in there, whereas this
one is strictly about AF_XDP.

Do s/xdpxceiver/xskxceiver so that it will be easier to figure out who
maintains it. A follow-up patch will correct MAINTAINERS file.

Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220707111613.49031-2-maciej.fijalkowski@intel.com

selftests/bpf: Add benchmark for local_storage RCU Tasks Trace usage

This benchmark measures grace period latency and kthread cpu usage of
RCU Tasks Trace when many processes are creating/deleting BPF
local_storage. Intent here is to quantify improvement on these metrics
after Paul's recent RCU Tasks patches [0].

Specifically, fork 15k tasks which call a bpf prog that creates/destroys
task local_storage and sleep in a loop, resulting in many
call_rcu_tasks_trace calls.

To determine grace period latency, trace time elapsed between
rcu_tasks_trace_pregp_step and rcu_tasks_trace_postgp; for cpu usage
look at rcu_task_trace_kthread's stime in /proc/PID/stat.

On my virtualized test environment (Skylake, 8 cpus) benchmark results
demonstrate significant improvement:

BEFORE Paul's patches:

SUMMARY tasks_trace grace period latency avg 22298.551 us stddev 1302.165 us
SUMMARY ticks per tasks_trace grace period avg 2.291 stddev 0.324

AFTER Paul's patches:

SUMMARY tasks_trace grace period latency avg 16969.197 us stddev 2525.053 us
SUMMARY ticks per tasks_trace grace period avg 1.146 stddev 0.178

Note that since these patches are not in bpf-next benchmarking was done
by cherry-picking this patch onto rcu tree.

[0] https://lore.kernel.org/rcu/20220620225402.GA3842369@paulmck-ThinkPad-P17-Gen-1/

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20220705190018.3239050-1-davemarchevsky@fb.com

libbpf: move xsk.{c,h} into selftests/bpf

Remove deprecated xsk APIs from libbpf. But given we have selftests
relying on this, move those files (with minimal adjustments to make them
compilable) under selftests/bpf.

We also remove all the removed APIs from libbpf.map, while overall
keeping version inheritance chain, as most APIs are backwards
compatible so there is no need to reassign them as LIBBPF_1.0.0 versions.

Cc: Magnus Karlsson <magnus.karlsson@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220627211527.2245459-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Add benchmark for local_storage get

Add a benchmarks to demonstrate the performance cliff for local_storage
get as the number of local_storage maps increases beyond current
local_storage implementation's cache size.

"sequential get" and "interleaved get" benchmarks are added, both of
which do many bpf_task_storage_get calls on sets of task local_storage
maps of various counts, while considering a single specific map to be
'important' and counting task_storage_gets to the important map
separately in addition to normal 'hits' count of all gets. Goal here is
to mimic scenario where a particular program using one map - the
important one - is running on a system where many other local_storage
maps exist and are accessed often.

While "sequential get" benchmark does bpf_task_storage_get for map 0, 1,
..., {9, 99, 999} in order, "interleaved" benchmark interleaves 4
bpf_task_storage_gets for the important map for every 10 map gets. This
is meant to highlight performance differences when important map is
accessed far more frequently than non-important maps.

A "hashmap control" benchmark is also included for easy comparison of
standard bpf hashmap lookup vs local_storage get. The benchmark is
similar to "sequential get", but creates and uses BPF_MAP_TYPE_HASH
instead of local storage. Only one inner map is created - a hashmap
meant to hold tid -> data mapping for all tasks. Size of the hashmap is
hardcoded to my system's PID_MAX_LIMIT (4,194,304). The number of these
keys which are actually fetched as part of the benchmark is
configurable.

Addition of this benchmark is inspired by conversation with Alexei in a
previous patchset's thread [0], which highlighted the need for such a
benchmark to motivate and validate improvements to local_storage
implementation. My approach in that series focused on improving
performance for explicitly-marked 'important' maps and was rejected
with feedback to make more generally-applicable improvements while
avoiding explicitly marking maps as important. Thus the benchmark
reports both general and important-map-focused metrics, so effect of
future work on both is clear.

Regarding the benchmark results. On a powerful system (Skylake, 20
cores, 256gb ram):

Hashmap Control
===============
num keys: 10
hashmap (control) sequential get: hits throughput: 20.900 ± 0.334 M ops/s, hits latency: 47.847 ns/op, important_hits throughput: 20.900 ± 0.334 M ops/s

num keys: 1000
hashmap (control) sequential get: hits throughput: 13.758 ± 0.219 M ops/s, hits latency: 72.683 ns/op, important_hits throughput: 13.758 ± 0.219 M ops/s

num keys: 10000
hashmap (control) sequential get: hits throughput: 6.995 ± 0.034 M ops/s, hits latency: 142.959 ns/op, important_hits throughput: 6.995 ± 0.034 M ops/s

num keys: 100000
hashmap (control) sequential get: hits throughput: 4.452 ± 0.371 M ops/s, hits latency: 224.635 ns/op, important_hits throughput: 4.452 ± 0.371 M ops/s

num keys: 4194304
hashmap (control) sequential get: hits throughput: 3.043 ± 0.033 M ops/s, hits latency: 328.587 ns/op, important_hits throughput: 3.043 ± 0.033 M ops/s

Local Storage
=============
num_maps: 1
local_storage cache sequential get: hits throughput: 47.298 ± 0.180 M ops/s, hits latency: 21.142 ns/op, important_hits throughput: 47.298 ± 0.180 M ops/s
local_storage cache interleaved get: hits throughput: 55.277 ± 0.888 M ops/s, hits latency: 18.091 ns/op, important_hits throughput: 55.277 ± 0.888 M ops/s

num_maps: 10
local_storage cache sequential get: hits throughput: 40.240 ± 0.802 M ops/s, hits latency: 24.851 ns/op, important_hits throughput: 4.024 ± 0.080 M ops/s
local_storage cache interleaved get: hits throughput: 48.701 ± 0.722 M ops/s, hits latency: 20.533 ns/op, important_hits throughput: 17.393 ± 0.258 M ops/s

num_maps: 16
local_storage cache sequential get: hits throughput: 44.515 ± 0.708 M ops/s, hits latency: 22.464 ns/op, important_hits throughput: 2.782 ± 0.044 M ops/s
local_storage cache interleaved get: hits throughput: 49.553 ± 2.260 M ops/s, hits latency: 20.181 ns/op, important_hits throughput: 15.767 ± 0.719 M ops/s

num_maps: 17
local_storage cache sequential get: hits throughput: 38.778 ± 0.302 M ops/s, hits latency: 25.788 ns/op, important_hits throughput: 2.284 ± 0.018 M ops/s
local_storage cache interleaved get: hits throughput: 43.848 ± 1.023 M ops/s, hits latency: 22.806 ns/op, important_hits throughput: 13.349 ± 0.311 M ops/s

num_maps: 24
local_storage cache sequential get: hits throughput: 19.317 ± 0.568 M ops/s, hits latency: 51.769 ns/op, important_hits throughput: 0.806 ± 0.024 M ops/s
local_storage cache interleaved get: hits throughput: 24.397 ± 0.272 M ops/s, hits latency: 40.989 ns/op, important_hits throughput: 6.863 ± 0.077 M ops/s

num_maps: 32
local_storage cache sequential get: hits throughput: 13.333 ± 0.135 M ops/s, hits latency: 75.000 ns/op, important_hits throughput: 0.417 ± 0.004 M ops/s
local_storage cache interleaved get: hits throughput: 16.898 ± 0.383 M ops/s, hits latency: 59.178 ns/op, important_hits throughput: 4.717 ± 0.107 M ops/s

num_maps: 100
local_storage cache sequential get: hits throughput: 6.360 ± 0.107 M ops/s, hits latency: 157.233 ns/op, important_hits throughput: 0.064 ± 0.001 M ops/s
local_storage cache interleaved get: hits throughput: 7.303 ± 0.362 M ops/s, hits latency: 136.930 ns/op, important_hits throughput: 1.907 ± 0.094 M ops/s

num_maps: 1000
local_storage cache sequential get: hits throughput: 0.452 ± 0.010 M ops/s, hits latency: 2214.022 ns/op, important_hits throughput: 0.000 ± 0.000 M ops/s
local_storage cache interleaved get: hits throughput: 0.542 ± 0.007 M ops/s, hits latency: 1843.341 ns/op, important_hits throughput: 0.136 ± 0.002 M ops/s

Looking at the "sequential get" results, it's clear that as the
number of task local_storage maps grows beyond the current cache size
(16), there's a significant reduction in hits throughput. Note that
current local_storage implementation assigns a cache_idx to maps as they
are created. Since "sequential get" is creating maps 0..n in order and
then doing bpf_task_storage_get calls in the same order, the benchmark
is effectively ensuring that a map will not be in cache when the program
tries to access it.

For "interleaved get" results, important-map hits throughput is greatly
increased as the important map is more likely to be in cache by virtue
of being accessed far more frequently. Throughput still reduces as #
maps increases, though.

To get a sense of the overhead of the benchmark program, I
commented out bpf_task_storage_get/bpf_map_lookup_elem in
local_storage_bench.c and ran the benchmark on the same host as the
'real' run. Results:

Hashmap Control
===============
num keys: 10
hashmap (control) sequential get: hits throughput: 54.288 ± 0.655 M ops/s, hits latency: 18.420 ns/op, important_hits throughput: 54.288 ± 0.655 M ops/s

num keys: 1000
hashmap (control) sequential get: hits throughput: 52.913 ± 0.519 M ops/s, hits latency: 18.899 ns/op, important_hits throughput: 52.913 ± 0.519 M ops/s

num keys: 10000
hashmap (control) sequential get: hits throughput: 53.480 ± 1.235 M ops/s, hits latency: 18.699 ns/op, important_hits throughput: 53.480 ± 1.235 M ops/s

num keys: 100000
hashmap (control) sequential get: hits throughput: 54.982 ± 1.902 M ops/s, hits latency: 18.188 ns/op, important_hits throughput: 54.982 ± 1.902 M ops/s

num keys: 4194304
hashmap (control) sequential get: hits throughput: 50.858 ± 0.707 M ops/s, hits latency: 19.662 ns/op, important_hits throughput: 50.858 ± 0.707 M ops/s

Local Storage
=============
num_maps: 1
local_storage cache sequential get: hits throughput: 110.990 ± 4.828 M ops/s, hits latency: 9.010 ns/op, important_hits throughput: 110.990 ± 4.828 M ops/s
local_storage cache interleaved get: hits throughput: 161.057 ± 4.090 M ops/s, hits latency: 6.209 ns/op, important_hits throughput: 161.057 ± 4.090 M ops/s

num_maps: 10
local_storage cache sequential get: hits throughput: 112.930 ± 1.079 M ops/s, hits latency: 8.855 ns/op, important_hits throughput: 11.293 ± 0.108 M ops/s
local_storage cache interleaved get: hits throughput: 115.841 ± 2.088 M ops/s, hits latency: 8.633 ns/op, important_hits throughput: 41.372 ± 0.746 M ops/s

num_maps: 16
local_storage cache sequential get: hits throughput: 115.653 ± 0.416 M ops/s, hits latency: 8.647 ns/op, important_hits throughput: 7.228 ± 0.026 M ops/s
local_storage cache interleaved get: hits throughput: 138.717 ± 1.649 M ops/s, hits latency: 7.209 ns/op, important_hits throughput: 44.137 ± 0.525 M ops/s

num_maps: 17
local_storage cache sequential get: hits throughput: 112.020 ± 1.649 M ops/s, hits latency: 8.927 ns/op, important_hits throughput: 6.598 ± 0.097 M ops/s
local_storage cache interleaved get: hits throughput: 128.089 ± 1.960 M ops/s, hits latency: 7.807 ns/op, important_hits throughput: 38.995 ± 0.597 M ops/s

num_maps: 24
local_storage cache sequential get: hits throughput: 92.447 ± 5.170 M ops/s, hits latency: 10.817 ns/op, important_hits throughput: 3.855 ± 0.216 M ops/s
local_storage cache interleaved get: hits throughput: 128.844 ± 2.808 M ops/s, hits latency: 7.761 ns/op, important_hits throughput: 36.245 ± 0.790 M ops/s

num_maps: 32
local_storage cache sequential get: hits throughput: 102.042 ± 1.462 M ops/s, hits latency: 9.800 ns/op, important_hits throughput: 3.194 ± 0.046 M ops/s
local_storage cache interleaved get: hits throughput: 126.577 ± 1.818 M ops/s, hits latency: 7.900 ns/op, important_hits throughput: 35.332 ± 0.507 M ops/s

num_maps: 100
local_storage cache sequential get: hits throughput: 111.327 ± 1.401 M ops/s, hits latency: 8.983 ns/op, important_hits throughput: 1.113 ± 0.014 M ops/s
local_storage cache interleaved get: hits throughput: 131.327 ± 1.339 M ops/s, hits latency: 7.615 ns/op, important_hits throughput: 34.302 ± 0.350 M ops/s

num_maps: 1000
local_storage cache sequential get: hits throughput: 101.978 ± 0.563 M ops/s, hits latency: 9.806 ns/op, important_hits throughput: 0.102 ± 0.001 M ops/s
local_storage cache interleaved get: hits throughput: 141.084 ± 1.098 M ops/s, hits latency: 7.088 ns/op, important_hits throughput: 35.430 ± 0.276 M ops/s

Adjusting for overhead, latency numbers for "hashmap control" and
"sequential get" are:

hashmap_control_1k: ~53.8ns
hashmap_control_10k: ~124.2ns
hashmap_control_100k: ~206.5ns
sequential_get_1: ~12.1ns
sequential_get_10: ~16.0ns
sequential_get_16: ~13.8ns
sequential_get_17: ~16.8ns
sequential_get_24: ~40.9ns
sequential_get_32: ~65.2ns
sequential_get_100: ~148.2ns
sequential_get_1000: ~2204ns

Clearly demonstrating a cliff.

In the discussion for v1 of this patch, Alexei noted that local_storage
was 2.5x faster than a large hashmap when initially implemented [1]. The
benchmark results show that local_storage is 5-10x faster: a
long-running BPF application putting some pid-specific info into a
hashmap for each pid it sees will probably see on the order of 10-100k
pids. Bench numbers for hashmaps of this size are ~10x slower than
sequential_get_16, but as the number of local_storage maps grows far
past local_storage cache size the performance advantage shrinks and
eventually reverses.

When running the benchmarks it may be necessary to bump 'open files'
ulimit for a successful run.

[0]: https://lore.kernel.org/all/20220420002143.1096548-1-davemarchevsky@fb.com
[1]: https://lore.kernel.org/bpf/20220511173305.ftldpn23m4ski3d3@MBP-98dd607d3435.dhcp.thefacebook.com/

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20220620222554.270578-1-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Don't force lld on non-x86 architectures

LLVM's lld linker doesn't have a universal architecture support (e.g.,
it definitely doesn't work on s390x), so be safe and force lld for
urandom_read and liburandom_read.so only on x86 architectures.

This should fix s390x CI runs.

Fixes: 3e6fe5ce4d48 ("libbpf: Fix internal USDT address translation logic for shared libraries")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220617045512.1339795-1-andrii@kernel.org

selftests/bpf: Add selftests for raw syncookie helpers

This commit adds selftests for the new BPF helpers:
bpf_tcp_raw_{gen,check}_syncookie_ipv{4,6}.

xdp_synproxy_kern.c is a BPF program that generates SYN cookies on
allowed TCP ports and sends SYNACKs to clients, accelerating synproxy
iptables module.

xdp_synproxy.c is a userspace control application that allows to
configure the following options in runtime: list of allowed ports, MSS,
window scale, TTL.

A selftest is added to prog_tests that leverages the above programs to
test the functionality of the new helpers.

Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://lore.kernel.org/r/20220615134847.3753567-5-maximmi@nvidia.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

libbpf: Fix internal USDT address translation logic for shared libraries

Perform the same virtual address to file offset translation that libbpf
is doing for executable ELF binaries also for shared libraries.
Currently libbpf is making a simplifying and sometimes wrong assumption
that for shared libraries relative virtual addresses inside ELF are
always equal to file offsets.

Unfortunately, this is not always the case with LLVM's lld linker, which
now by default generates quite more complicated ELF segments layout.
E.g., for liburandom_read.so from selftests/bpf, here's an excerpt from
readelf output listing ELF segments (a.k.a. program headers):

Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align
PHDR 0x000040 0x0000000000000040 0x0000000000000040 0x0001f8 0x0001f8 R 0x8
LOAD 0x000000 0x0000000000000000 0x0000000000000000 0x0005e4 0x0005e4 R 0x1000
LOAD 0x0005f0 0x00000000000015f0 0x00000000000015f0 0x000160 0x000160 R E 0x1000
LOAD 0x000750 0x0000000000002750 0x0000000000002750 0x000210 0x000210 RW 0x1000
LOAD 0x000960 0x0000000000003960 0x0000000000003960 0x000028 0x000029 RW 0x1000

Compare that to what is generated by GNU ld (or LLVM lld's with extra
-znoseparate-code argument which disables this cleverness in the name of
file size reduction):

Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align
LOAD 0x000000 0x0000000000000000 0x0000000000000000 0x000550 0x000550 R 0x1000
LOAD 0x001000 0x0000000000001000 0x0000000000001000 0x000131 0x000131 R E 0x1000
LOAD 0x002000 0x0000000000002000 0x0000000000002000 0x0000ac 0x0000ac R 0x1000
LOAD 0x002dc0 0x0000000000003dc0 0x0000000000003dc0 0x000262 0x000268 RW 0x1000

You can see from the first example above that for executable (Flg == "R E")
PT_LOAD segment (LOAD #2), Offset doesn't match VirtAddr columns.
And it does in the second case (GNU ld output).

This is important because all the addresses, including USDT specs,
operate in a virtual address space, while kernel is expecting file
offsets when performing uprobe attach. So such mismatches have to be
properly taken care of and compensated by libbpf, which is what this
patch is fixing.

Also patch clarifies few function and variable names, as well as updates
comments to reflect this important distinction (virtaddr vs file offset)
and to ephasize that shared libraries are not all that different from
executables in this regard.

This patch also changes selftests/bpf Makefile to force urand_read and
liburand_read.so to be built with Clang and LLVM's lld (and explicitly
request this ELF file size optimization through -znoseparate-code linker
parameter) to validate libbpf logic and ensure regressions don't happen
in the future. I've bundled these selftests changes together with libbpf
changes to keep the above description tied with both libbpf and
selftests changes.

Fixes: 74cc6311cec9 ("libbpf: Add USDT notes parsing and resolution logic")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220616055543.3285835-1-andrii@kernel.org

selftest/bpf/benchs: Add bpf_map benchmark

Add benchmark for hash_map to reproduce the worst case
that non-stop update when map's free is zero.

Just like this:
./run_bench_bpf_hashmap_full_update.sh
Setting up benchmark 'bpf-hashmap-ful-update'...
Benchmark 'bpf-hashmap-ful-update' started.
1:hash_map_full_perf 555830 events per sec
...

Signed-off-by: Feng Zhou <zhoufeng.zf@bytedance.com>
Link: https://lore.kernel.org/r/20220610023308.93798-3-zhoufeng.zf@bytedance.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Add missed ima_setup.sh in Makefile

When build bpf test and install it to another folder, e.g.

make -j10 install -C tools/testing/selftests/ TARGETS="bpf" \
SKIP_TARGETS="" INSTALL_PATH=/tmp/kselftests

The ima_setup.sh is missed in target folder, which makes test_ima failed.

Fix it by adding ima_setup.sh to TEST_PROGS_EXTENDED.

Fixes: 34b82d3ac105 ("bpf: Add a selftest for bpf_ima_inode_hash")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20220516040020.653291-1-liuhangbin@gmail.com

selftests/bpf: Fix building bpf selftests statically

bpf selftests can no longer be built with CFLAGS=-static with
liburandom_read.so and its dependent target.

Filter out -static for liburandom_read.so and its dependent target.

When building statically, this leaves urandom_read relying on
system-wide shared libraries.

Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220514002115.1376033-1-yosryahmed@google.com

selftests/bpf: Prevent skeleton generation race

Prevent "classic" and light skeleton generation rules from stomping on
each other's toes due to the use of the same <obj>.linked{1,2,3}.o
naming pattern. There is no coordination and synchronizataion between
.skel.h and .lskel.h rules, so they can easily overwrite each other's
intermediate object files, leading to errors like:

/bin/sh: line 1: 170928 Bus error (core dumped)
/data/users/andriin/linux/tools/testing/selftests/bpf/tools/sbin/bpftool gen skeleton
/data/users/andriin/linux/tools/testing/selftests/bpf/test_ksyms_weak.linked3.o
name test_ksyms_weak
> /data/users/andriin/linux/tools/testing/selftests/bpf/test_ksyms_weak.skel.h
make: *** [Makefile:507: /data/users/andriin/linux/tools/testing/selftests/bpf/test_ksyms_weak.skel.h] Error 135
make: *** Deleting file '/data/users/andriin/linux/tools/testing/selftests/bpf/test_ksyms_weak.skel.h'

Fix by using different suffix for light skeleton rule.

Fixes: c48e51c8b07a ("bpf: selftests: Add selftests for module kfunc support")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220509004148.1801791-2-andrii@kernel.org

selftests/bpf: Add urandom_read shared lib and USDTs

Extend urandom_read helper binary to include USDTs of 4 combinations:
semaphore/semaphoreless (refcounted and non-refcounted) and based in
executable or shared library. We also extend urandom_read with ability
to report it's own PID to parent process and wait for parent process to
ready itself up for tracing urandom_read. We utilize popen() and
underlying pipe properties for proper signaling.

Once urandom_read is ready, we add few tests to validate that libbpf's
USDT attachment handles all the above combinations of semaphore (or lack
of it) and static or shared library USDTs. Also, we validate that libbpf
handles shared libraries both with PID filter and without one (i.e., -1
for PID argument).

Having the shared library case tested with and without PID is important
because internal logic differs on kernels that don't support BPF
cookies. On such older kernels, attaching to USDTs in shared libraries
without specifying concrete PID doesn't work in principle, because it's
impossible to determine shared library's load address to derive absolute
IPs for uprobe attachments. Without absolute IPs, it's impossible to
perform correct look up of USDT spec based on uprobe's absolute IP (the
only kind available from BPF at runtime). This is not the problem on
newer kernels with BPF cookie as we don't need IP-to-ID lookup because
BPF cookie value *is* spec ID.

So having those two situations as separate subtests is good because
libbpf CI is able to test latest selftests against old kernels (e.g.,
4.9 and 5.5), so we'll be able to disable PID-less shared lib attachment
for old kernels, but will still leave PID-specific one enabled to validate
this legacy logic is working correctly.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20220404234202.331384-8-andrii@kernel.org

selftests/bpf: Add basic USDT selftests

Add semaphore-based USDT to test_progs itself and write basic tests to
valicate both auto-attachment and manual attachment logic, as well as
BPF-side functionality.

Also add subtests to validate that libbpf properly deduplicates USDT
specs and handles spec overflow situations correctly, as well as proper
"rollback" of partially-attached multi-spec USDT.

BPF-side of selftest intentionally consists of two files to validate
that usdt.bpf.h header can be included from multiple source code files
that are subsequently linked into final BPF object file without causing
any symbol duplication or other issues. We are validating that __weak
maps and bpf_usdt_xxx() API functions defined in usdt.bpf.h do work as
intended.

USDT selftests utilize sys/sdt.h header that on Ubuntu systems comes
from systemtap-sdt-devel package. But to simplify everyone's life,
including CI but especially casual contributors to bpf/bpf-next that
are trying to build selftests, I've checked in sys/sdt.h header from [0]
directly. This way it will work on all architectures and distros without
having to figure it out for every relevant combination and adding any
extra implicit package dependencies.

[0] https://sourceware.org/git?p=systemtap.git;a=blob_plain;f=includes/sys/sdt.h;h=ca0162b4dc57520b96638c8ae79ad547eb1dd3a1;hb=HEAD

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20220404234202.331384-7-andrii@kernel.org

selftests/bpf: Test subskeleton functionality

This patch changes the selftests/bpf Makefile to also generate
a subskel.h for every skel.h it would have normally generated.

Separately, it also introduces a new subskeleton test which tests
library objects, externs, weak symbols, kconfigs, and user maps.

Signed-off-by: Delyan Kratunov <delyank@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1bd24956940bbbfe169bb34f7f87b11df52ef011.1647473511.git.delyank@fb.com

bpf: selftests: Remove libcap usage from test_progs

This patch removes the libcap usage from test_progs.
bind_perm.c is the only user. cap_*_effective() helpers added in the
earlier patch are directly used instead.

No other selftest binary is using libcap, so '-lcap' is also removed
from the Makefile.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20220316173835.2039334-1-kafai@fb.com

bpf: selftests: Remove libcap usage from test_verifier

This patch removes the libcap usage from test_verifier.
The cap_*_effective() helpers added in the earlier patch are
used instead.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20220316173829.2038682-1-kafai@fb.com

selftests/bpf: Fix btfgen tests

There turned out to be a few problems with btfgen selftests.

First, core_btfgen tests are failing in BPF CI due to the use of
full-featured bpftool, which has extra dependencies on libbfd, libcap,
etc, which are present in BPF CI's build environment, but those shared
libraries are missing in QEMU image in which test_progs is running.

To fix this problem, use minimal bootstrap version of bpftool instead.
It only depend on libelf and libz, same as libbpf, so doesn't add any
new requirements (and bootstrap bpftool still implementes entire
`bpftool gen` functionality, which is quite convenient).

Second problem is even more interesting. Both core_btfgen and core_reloc
reuse the same set of struct core_reloc_test_case array of test case
definitions. That in itself is not a problem, but btfgen test replaces
test_case->btf_src_file property with the path to temporary file into
which minimized BTF is output by bpftool. This interferes with original
core_reloc tests, depending on order of tests execution (core_btfgen is
run first in sequential mode and skrews up subsequent core_reloc run by
pointing to already deleted temporary file, instead of the original BTF
files) and whether those two runs share the same process (in parallel
mode the chances are high for them to run in two separate processes and
so not interfere with each other).

To prevent this interference, create and use local copy of a test
definition. Mark original array as constant to catch accidental
modifcations. Note that setup_type_id_case_success() and
setup_type_id_case_success() still modify common test_case->output
memory area, but it is ok as each setup function has to re-initialize it
completely anyways. In sequential mode it leads to deterministic and
correct initialization. In parallel mode they will either each have
their own process, or if core_reloc and core_btfgen happen to be run by
the same worker process, they will still do that sequentially within the
worker process. If they are sharded across multiple processes, they
don't really share anything anyways.

Also, rename core_btfgen into core_reloc_btfgen, as it is indeed just
a "flavor" of core_reloc test, not an independent set of tests. So make
it more obvious.

Last problem that needed solving was that location of bpftool differs
between test_progs and test_progs' flavors (e.g., test_progs-no_alu32).
To keep it simple, create a symlink to bpftool both inside
selftests/bpf/ directory and selftests/bpf/<flavor> subdirectory. That
way, from inside core_reloc test, location to bpftool is just "./bpftool".

v2->v3:
- fix bpftool location relative the test_progs-no_alu32;
v1->v2:
- fix corruption of core_reloc_test_case.

Fixes: 704c91e59fe0 ("selftests/bpf: Test "bpftool gen min_core_btf")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yucong Sun <sunyucong@gmail.com>
Link: https://lore.kernel.org/bpf/20220220042720.3336684-1-andrii@kernel.org

selftests/bpf: Test bpf_core_types_are_compat() functionality.

Add several tests to check bpf_core_types_are_compat() functionality:
- candidate type name exists and types match
- candidate type name exists but types don't match
- nested func protos at kernel recursion limit
- nested func protos above kernel recursion limit. Such bpf prog
is rejected during the load.

Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220204005519.60361-3-mcroce@linux.microsoft.com

selftests/bpf: fail build on compilation warning

It's very easy to miss compilation warnings without -Werror, which is
not set for selftests. libbpf and bpftool are already strict about this,
so make selftests/bpf also treat compilation warnings as errors to catch
such regressions early.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220120060529.1890907-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Enable cross-building with clang

Cross building using clang requires passing the "-target" flag rather
than using the CROSS_COMPILE prefix. Makefile.include transforms
CROSS_COMPILE into CLANG_CROSS_FLAGS. Clear CROSS_COMPILE for bpftool
and the host libbpf, and use the clang flags for urandom_read and bench.

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20211216163842.829836-7-jean-philippe@linaro.org

selftests/bpf: Add benchmark for bpf_strncmp() helper

Add benchmark to compare the performance between home-made strncmp()
in bpf program and bpf_strncmp() helper. In summary, the performance
win of bpf_strncmp() under x86-64 is greater than 18% when the compared
string length is greater than 64, and is 179% when the length is 4095.
Under arm64 the performance win is even bigger: 33% when the length
is greater than 64 and 600% when the length is 4095.

The following is the details:

no-helper-X: use home-made strncmp() to compare X-sized string
helper-Y: use bpf_strncmp() to compare Y-sized string

Under x86-64:

no-helper-1 3.504 ± 0.000M/s (drops 0.000 ± 0.000M/s)
helper-1 3.347 ± 0.001M/s (drops 0.000 ± 0.000M/s)

no-helper-8 3.357 ± 0.001M/s (drops 0.000 ± 0.000M/s)
helper-8 3.307 ± 0.001M/s (drops 0.000 ± 0.000M/s)

no-helper-32 3.064 ± 0.000M/s (drops 0.000 ± 0.000M/s)
helper-32 3.253 ± 0.001M/s (drops 0.000 ± 0.000M/s)

no-helper-64 2.563 ± 0.001M/s (drops 0.000 ± 0.000M/s)
helper-64 3.040 ± 0.001M/s (drops 0.000 ± 0.000M/s)

no-helper-128 1.975 ± 0.000M/s (drops 0.000 ± 0.000M/s)
helper-128 2.641 ± 0.000M/s (drops 0.000 ± 0.000M/s)

no-helper-512 0.759 ± 0.000M/s (drops 0.000 ± 0.000M/s)
helper-512 1.574 ± 0.000M/s (drops 0.000 ± 0.000M/s)

no-helper-2048 0.329 ± 0.000M/s (drops 0.000 ± 0.000M/s)
helper-2048 0.602 ± 0.000M/s (drops 0.000 ± 0.000M/s)

no-helper-4095 0.117 ± 0.000M/s (drops 0.000 ± 0.000M/s)
helper-4095 0.327 ± 0.000M/s (drops 0.000 ± 0.000M/s)

Under arm64:

no-helper-1 2.806 ± 0.004M/s (drops 0.000 ± 0.000M/s)
helper-1 2.819 ± 0.002M/s (drops 0.000 ± 0.000M/s)

no-helper-8 2.797 ± 0.109M/s (drops 0.000 ± 0.000M/s)
helper-8 2.786 ± 0.025M/s (drops 0.000 ± 0.000M/s)

no-helper-32 2.399 ± 0.011M/s (drops 0.000 ± 0.000M/s)
helper-32 2.703 ± 0.002M/s (drops 0.000 ± 0.000M/s)

no-helper-64 2.020 ± 0.015M/s (drops 0.000 ± 0.000M/s)
helper-64 2.702 ± 0.073M/s (drops 0.000 ± 0.000M/s)

no-helper-128 1.604 ± 0.001M/s (drops 0.000 ± 0.000M/s)
helper-128 2.516 ± 0.002M/s (drops 0.000 ± 0.000M/s)

no-helper-512 0.699 ± 0.000M/s (drops 0.000 ± 0.000M/s)
helper-512 2.106 ± 0.003M/s (drops 0.000 ± 0.000M/s)

no-helper-2048 0.215 ± 0.000M/s (drops 0.000 ± 0.000M/s)
helper-2048 1.223 ± 0.003M/s (drops 0.000 ± 0.000M/s)

no-helper-4095 0.112 ± 0.000M/s (drops 0.000 ± 0.000M/s)
helper-4095 0.796 ± 0.000M/s (drops 0.000 ± 0.000M/s)

Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211210141652.877186-4-houtao1@huawei.com

selftests/bpf: Build testing_helpers.o out of tree

Add $(OUTPUT) prefix to testing_helpers.o, so it can be built out of
tree when necessary. At the moment, in addition to being built in-tree
even when out-of-tree is required, testing_helpers.o is not built with
the right recipe when cross-building.

For consistency the other helpers, cgroup_helpers and trace_helpers, can
also be passed as objects instead of source. Use *_HELPERS variable to
keep the Makefile readable.

Fixes: f87c1930ac29 ("selftests/bpf: Merge test_stub.c into testing_helpers.c")
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211201145101.823159-1-jean-philippe@linaro.org

selftests/bpf: Additional test for CO-RE in the kernel.

Add a test where randmap() function is appended to three different bpf
programs. That action checks struct bpf_core_relo replication logic
and offset adjustment in gen loader part of libbpf.

Fourth bpf program has 360 CO-RE relocations from vmlinux, bpf_testmod,
and non-existing type. It tests candidate cache logic.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211201181040.23337-16-alexei.starovoitov@gmail.com

selftests/bpf: Convert map_ptr_kern test to use light skeleton.

To exercise CO-RE in the kernel further convert map_ptr_kern
test to light skeleton.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211201181040.23337-15-alexei.starovoitov@gmail.com

selftests/bpf: Add lskel version of kfunc test.

Add light skeleton version of kfunc_call_test_subprog test.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211201181040.23337-13-alexei.starovoitov@gmail.com

selftest/bpf/benchs: Add bpf_loop benchmark

Add benchmark to measure the throughput and latency of the bpf_loop
call.

Testing this on my dev machine on 1 thread, the data is as follows:

nr_loops: 10
bpf_loop - throughput: 198.519 ± 0.155 M ops/s, latency: 5.037 ns/op

nr_loops: 100
bpf_loop - throughput: 247.448 ± 0.305 M ops/s, latency: 4.041 ns/op

nr_loops: 500
bpf_loop - throughput: 260.839 ± 0.380 M ops/s, latency: 3.834 ns/op

nr_loops: 1000
bpf_loop - throughput: 262.806 ± 0.629 M ops/s, latency: 3.805 ns/op

nr_loops: 5000
bpf_loop - throughput: 264.211 ± 1.508 M ops/s, latency: 3.785 ns/op

nr_loops: 10000
bpf_loop - throughput: 265.366 ± 3.054 M ops/s, latency: 3.768 ns/op

nr_loops: 50000
bpf_loop - throughput: 235.986 ± 20.205 M ops/s, latency: 4.238 ns/op

nr_loops: 100000
bpf_loop - throughput: 264.482 ± 0.279 M ops/s, latency: 3.781 ns/op

nr_loops: 500000
bpf_loop - throughput: 309.773 ± 87.713 M ops/s, latency: 3.228 ns/op

nr_loops: 1000000
bpf_loop - throughput: 262.818 ± 4.143 M ops/s, latency: 3.805 ns/op

>From this data, we can see that the latency per loop decreases as the
number of loops increases. On this particular machine, each loop had an
overhead of about ~4 ns, and we were able to run ~250 million loops
per second.

Signed-off-by: Joanne Koong <joannekoong@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211130030622.4131246-5-joannekoong@fb.com

selftests/bpf: Add uprobe triggering overhead benchmarks

Add benchmark to measure overhead of uprobes and uretprobes. Also have
a baseline (no uprobe attached) benchmark.

On my dev machine, baseline benchmark can trigger 130M user_target()
invocations. When uprobe is attached, this falls to just 700K. With
uretprobe, we get down to 520K:

$ sudo ./bench trig-uprobe-base -a
Summary: hits 131.289 ± 2.872M/s

# UPROBE
$ sudo ./bench -a trig-uprobe-without-nop
Summary: hits 0.729 ± 0.007M/s

$ sudo ./bench -a trig-uprobe-with-nop
Summary: hits 1.798 ± 0.017M/s

# URETPROBE
$ sudo ./bench -a trig-uretprobe-without-nop
Summary: hits 0.508 ± 0.012M/s

$ sudo ./bench -a trig-uretprobe-with-nop
Summary: hits 0.883 ± 0.008M/s

So there is almost 2.5x performance difference between probing nop vs
non-nop instruction for entry uprobe. And 1.7x difference for uretprobe.

This means that non-nop uprobe overhead is around 1.4 microseconds for uprobe
and 2 microseconds for non-nop uretprobe.

For nop variants, uprobe and uretprobe overhead is down to 0.556 and
1.13 microseconds, respectively.

For comparison, just doing a very low-overhead syscall (with no BPF
programs attached anywhere) gives:

$ sudo ./bench trig-base -a
Summary: hits 4.830 ± 0.036M/s

So uprobes are about 2.67x slower than pure context switch.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211116013041.4072571-1-andrii@kernel.org

selftests/bpf: Minor cleanups and normalization of Makefile

Few clean ups and single-line simplifications. Also split CLEAN command
into multiple $(RM) invocations as it gets dangerously close to too long
argument list. Make sure that -o <output.o> is used always as the last
argument for saner verbose make output.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211111053624.190580-3-andrii@kernel.org

selftests/bpf: Pass sanitizer flags to linker through LDFLAGS

When adding -fsanitize=address to SAN_CFLAGS, it has to be passed both
to compiler through CFLAGS as well as linker through LDFLAGS. Add
SAN_CFLAGS into LDFLAGS to allow building selftests with ASAN.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Hengqi Chen <hengqi.chen@gmail.com>
Link: https://lore.kernel.org/bpf/20211107165521.9240-2-andrii@kernel.org

selftests/bpf: Use explicit bpf_test_load_program() helper calls

Remove the second part of prog loading testing helper re-definition:

-Dbpf_load_program=bpf_test_load_program

This completes the clean up of deprecated libbpf program loading APIs.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20211103220845.2676888-13-andrii@kernel.org

selftests/bpf: Use explicit bpf_prog_test_load() calls everywhere

-Dbpf_prog_load_deprecated=bpf_prog_test_load trick is both ugly and
breaks when deprecation goes into effect due to macro magic. Convert all
the uses to explicit bpf_prog_test_load() calls which avoid deprecation
errors and makes everything less magical.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20211103220845.2676888-12-andrii@kernel.org

selftests/bpf: Merge test_stub.c into testing_helpers.c

Move testing prog and object load wrappers (bpf_prog_test_load and
bpf_test_load_program) into testing_helpers.{c,h} and get rid of
otherwise useless test_stub.c. Make testing_helpers.c available to
non-test_progs binaries as well.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20211103220845.2676888-11-andrii@kernel.org

libbpf: Unify low-level BPF_PROG_LOAD APIs into bpf_prog_load()

Add a new unified OPTS-based low-level API for program loading,
bpf_prog_load() ([0]). bpf_prog_load() accepts few "mandatory"
parameters as input arguments (program type, name, license,
instructions) and all the other optional (as in not required to specify
for all types of BPF programs) fields into struct bpf_prog_load_opts.

This makes all the other non-extensible APIs variant for BPF_PROG_LOAD
obsolete and they are slated for deprecation in libbpf v0.7:
- bpf_load_program();
- bpf_load_program_xattr();
- bpf_verify_program().

Implementation-wise, internal helper libbpf__bpf_prog_load is refactored
to become a public bpf_prog_load() API. struct bpf_prog_load_params used
internally is replaced by public struct bpf_prog_load_opts.

Unfortunately, while conceptually all this is pretty straightforward,
the biggest complication comes from the already existing bpf_prog_load()
*high-level* API, which has nothing to do with BPF_PROG_LOAD command.

We try really hard to have a new API named bpf_prog_load(), though,
because it maps naturally to BPF_PROG_LOAD command.

For that, we rename old bpf_prog_load() into bpf_prog_load_deprecated()
and mark it as COMPAT_VERSION() for shared library users compiled
against old version of libbpf. Statically linked users and shared lib
users compiled against new version of libbpf headers will get "rerouted"
to bpf_prog_deprecated() through a macro helper that decides whether to
use new or old bpf_prog_load() based on number of input arguments (see
___libbpf_overload in libbpf_common.h).

To test that existing
bpf_prog_load()-using code compiles and works as expected, I've compiled
and ran selftests as is. I had to remove (locally) selftest/bpf/Makefile
-Dbpf_prog_load=bpf_prog_test_load hack because it was conflicting with
the macro-based overload approach. I don't expect anyone else to do
something like this in practice, though. This is testing-specific way to
replace bpf_prog_load() calls with special testing variant of it, which
adds extra prog_flags value. After testing I kept this selftests hack,
but ensured that we use a new bpf_prog_load_deprecated name for this.

This patch also marks bpf_prog_load() and bpf_prog_load_xattr() as deprecated.
bpf_object interface has to be used for working with struct bpf_program.
Libbpf doesn't support loading just a bpf_program.

The silver lining is that when we get to libbpf 1.0 all these
complication will be gone and we'll have one clean bpf_prog_load()
low-level API with no backwards compatibility hackery surrounding it.

[0] Closes: https://github.com/libbpf/libbpf/issues/284

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211103220845.2676888-4-andrii@kernel.org

tools/runqslower: Fix cross-build

Commit be79505caf3f ("tools/runqslower: Install libbpf headers when
building") uses the target libbpf to build the host bpftool, which
doesn't work when cross-building:

make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- -C tools/bpf/runqslower O=/tmp/runqslower
...
LINK /tmp/runqslower/bpftool/bpftool
/usr/bin/ld: /tmp/runqslower/libbpf/libbpf.a(libbpf-in.o): Relocations in generic ELF (EM: 183)
/usr/bin/ld: /tmp/runqslower/libbpf/libbpf.a: error adding symbols: file in wrong format
collect2: error: ld returned 1 exit status

When cross-building, the target architecture differs from the host. The
bpftool used for building runqslower is executed on the host, and thus
must use a different libbpf than that used for runqslower itself.
Remove the LIBBPF_OUTPUT and LIBBPF_DESTDIR parameters, so the bpftool
build makes its own library if necessary.

In the selftests, pass the host bpftool, already a prerequisite for the
runqslower recipe, as BPFTOOL_OUTPUT. The runqslower Makefile will use
the bpftool that's already built for selftests instead of making a new
one.

Fixes: be79505caf3f ("tools/runqslower: Install libbpf headers when building")
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20211112155128.565680-1-jean-philippe@linaro.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests, bpf: Fix broken riscv build

This patch is closely related to commit 6016df8fe874 ("selftests/bpf:
Fix broken riscv build"). When clang includes the system include
directories, but targeting BPF program, __BITS_PER_LONG defaults to
32, unless explicitly set. Work around this problem, by explicitly
setting __BITS_PER_LONG to __riscv_xlen.

Signed-off-by: Björn Töpel <bjorn@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211028161057.520552-5-bjorn@kernel.org

selftests/bpf: Add weak/typeless ksym test for light skeleton

Also, avoid using CO-RE features, as lskel doesn't support CO-RE, yet.
Include both light and libbpf skeleton in same file to test both of them
together.

In c48e51c8b07a ("bpf: selftests: Add selftests for module kfunc support"),
I added support for generating both lskel and libbpf skel for a BPF
object, however the name parameter for bpftool caused collisions when
included in same file together. This meant that every test needed a
separate file for a libbpf/light skeleton separation instead of
subtests.

Change that by appending a "_lskel" suffix to the name for files using
light skeleton, and convert all existing users.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211028063501.2239335-7-memxor@gmail.com

bpf/benchs: Add benchmark tests for bloom filter throughput + false positive

This patch adds benchmark tests for the throughput (for lookups + updates)
and the false positive rate of bloom filter lookups, as well as some
minor refactoring of the bash script for running the benchmarks.

These benchmarks show that as the number of hash functions increases,
the throughput and the false positive rate of the bloom filter decreases.
>From the benchmark data, the approximate average false-positive rates
are roughly as follows:

1 hash function = ~30%
2 hash functions = ~15%
3 hash functions = ~5%
4 hash functions = ~2.5%
5 hash functions = ~1%
6 hash functions = ~0.5%
7 hash functions = ~0.35%
8 hash functions = ~0.15%
9 hash functions = ~0.1%
10 hash functions = ~0%

For reference data, the benchmarks run on one thread on a machine
with one numa node for 1 to 5 hash functions for 8-byte and 64-byte
values are as follows:

1 hash function:
50k entries
8-byte value
Lookups - 51.1 M/s operations
Updates - 33.6 M/s operations
False positive rate: 24.15%
64-byte value
Lookups - 15.7 M/s operations
Updates - 15.1 M/s operations
False positive rate: 24.2%
100k entries
8-byte value
Lookups - 51.0 M/s operations
Updates - 33.4 M/s operations
False positive rate: 24.04%
64-byte value
Lookups - 15.6 M/s operations
Updates - 14.6 M/s operations
False positive rate: 24.06%
500k entries
8-byte value
Lookups - 50.5 M/s operations
Updates - 33.1 M/s operations
False positive rate: 27.45%
64-byte value
Lookups - 15.6 M/s operations
Updates - 14.2 M/s operations
False positive rate: 27.42%
1 mil entries
8-byte value
Lookups - 49.7 M/s operations
Updates - 32.9 M/s operations
False positive rate: 27.45%
64-byte value
Lookups - 15.4 M/s operations
Updates - 13.7 M/s operations
False positive rate: 27.58%
2.5 mil entries
8-byte value
Lookups - 47.2 M/s operations
Updates - 31.8 M/s operations
False positive rate: 30.94%
64-byte value
Lookups - 15.3 M/s operations
Updates - 13.2 M/s operations
False positive rate: 30.95%
5 mil entries
8-byte value
Lookups - 41.1 M/s operations
Updates - 28.1 M/s operations
False positive rate: 31.01%
64-byte value
Lookups - 13.3 M/s operations
Updates - 11.4 M/s operations
False positive rate: 30.98%

2 hash functions:
50k entries
8-byte value
Lookups - 34.1 M/s operations
Updates - 20.1 M/s operations
False positive rate: 9.13%
64-byte value
Lookups - 8.4 M/s operations
Updates - 7.9 M/s operations
False positive rate: 9.21%
100k entries
8-byte value
Lookups - 33.7 M/s operations
Updates - 18.9 M/s operations
False positive rate: 9.13%
64-byte value
Lookups - 8.4 M/s operations
Updates - 7.7 M/s operations
False positive rate: 9.19%
500k entries
8-byte value
Lookups - 32.7 M/s operations
Updates - 18.1 M/s operations
False positive rate: 12.61%
64-byte value
Lookups - 8.4 M/s operations
Updates - 7.5 M/s operations
False positive rate: 12.61%
1 mil entries
8-byte value
Lookups - 30.6 M/s operations
Updates - 18.9 M/s operations
False positive rate: 12.54%
64-byte value
Lookups - 8.0 M/s operations
Updates - 7.0 M/s operations
False positive rate: 12.52%
2.5 mil entries
8-byte value
Lookups - 25.3 M/s operations
Updates - 16.7 M/s operations
False positive rate: 16.77%
64-byte value
Lookups - 7.9 M/s operations
Updates - 6.5 M/s operations
False positive rate: 16.88%
5 mil entries
8-byte value
Lookups - 20.8 M/s operations
Updates - 14.7 M/s operations
False positive rate: 16.78%
64-byte value
Lookups - 7.0 M/s operations
Updates - 6.0 M/s operations
False positive rate: 16.78%

3 hash functions:
50k entries
8-byte value
Lookups - 25.1 M/s operations
Updates - 14.6 M/s operations
False positive rate: 7.65%
64-byte value
Lookups - 5.8 M/s operations
Updates - 5.5 M/s operations
False positive rate: 7.58%
100k entries
8-byte value
Lookups - 24.7 M/s operations
Updates - 14.1 M/s operations
False positive rate: 7.71%
64-byte value
Lookups - 5.8 M/s operations
Updates - 5.3 M/s operations
False positive rate: 7.62%
500k entries
8-byte value
Lookups - 22.9 M/s operations
Updates - 13.9 M/s operations
False positive rate: 2.62%
64-byte value
Lookups - 5.6 M/s operations
Updates - 4.8 M/s operations
False positive rate: 2.7%
1 mil entries
8-byte value
Lookups - 19.8 M/s operations
Updates - 12.6 M/s operations
False positive rate: 2.60%
64-byte value
Lookups - 5.3 M/s operations
Updates - 4.4 M/s operations
False positive rate: 2.69%
2.5 mil entries
8-byte value
Lookups - 16.2 M/s operations
Updates - 10.7 M/s operations
False positive rate: 4.49%
64-byte value
Lookups - 4.9 M/s operations
Updates - 4.1 M/s operations
False positive rate: 4.41%
5 mil entries
8-byte value
Lookups - 18.8 M/s operations
Updates - 9.2 M/s operations
False positive rate: 4.45%
64-byte value
Lookups - 5.2 M/s operations
Updates - 3.9 M/s operations
False positive rate: 4.54%

4 hash functions:
50k entries
8-byte value
Lookups - 19.7 M/s operations
Updates - 11.1 M/s operations
False positive rate: 1.01%
64-byte value
Lookups - 4.4 M/s operations
Updates - 4.0 M/s operations
False positive rate: 1.00%
100k entries
8-byte value
Lookups - 19.5 M/s operations
Updates - 10.9 M/s operations
False positive rate: 1.00%
64-byte value
Lookups - 4.3 M/s operations
Updates - 3.9 M/s operations
False positive rate: 0.97%
500k entries
8-byte value
Lookups - 18.2 M/s operations
Updates - 10.6 M/s operations
False positive rate: 2.05%
64-byte value
Lookups - 4.3 M/s operations
Updates - 3.7 M/s operations
False positive rate: 2.05%
1 mil entries
8-byte value
Lookups - 15.5 M/s operations
Updates - 9.6 M/s operations
False positive rate: 1.99%
64-byte value
Lookups - 4.0 M/s operations
Updates - 3.4 M/s operations
False positive rate: 1.99%
2.5 mil entries
8-byte value
Lookups - 13.8 M/s operations
Updates - 7.7 M/s operations
False positive rate: 3.91%
64-byte value
Lookups - 3.7 M/s operations
Updates - 3.6 M/s operations
False positive rate: 3.78%
5 mil entries
8-byte value
Lookups - 13.0 M/s operations
Updates - 6.9 M/s operations
False positive rate: 3.93%
64-byte value
Lookups - 3.5 M/s operations
Updates - 3.7 M/s operations
False positive rate: 3.39%

5 hash functions:
50k entries
8-byte value
Lookups - 16.4 M/s operations
Updates - 9.1 M/s operations
False positive rate: 0.78%
64-byte value
Lookups - 3.5 M/s operations
Updates - 3.2 M/s operations
False positive rate: 0.77%
100k entries
8-byte value
Lookups - 16.3 M/s operations
Updates - 9.0 M/s operations
False positive rate: 0.79%
64-byte value
Lookups - 3.5 M/s operations
Updates - 3.2 M/s operations
False positive rate: 0.78%
500k entries
8-byte value
Lookups - 15.1 M/s operations
Updates - 8.8 M/s operations
False positive rate: 1.82%
64-byte value
Lookups - 3.4 M/s operations
Updates - 3.0 M/s operations
False positive rate: 1.78%
1 mil entries
8-byte value
Lookups - 13.2 M/s operations
Updates - 7.8 M/s operations
False positive rate: 1.81%
64-byte value
Lookups - 3.2 M/s operations
Updates - 2.8 M/s operations
False positive rate: 1.80%
2.5 mil entries
8-byte value
Lookups - 10.5 M/s operations
Updates - 5.9 M/s operations
False positive rate: 0.29%
64-byte value
Lookups - 3.2 M/s operations
Updates - 2.4 M/s operations
False positive rate: 0.28%
5 mil entries
8-byte value
Lookups - 9.6 M/s operations
Updates - 5.7 M/s operations
False positive rate: 0.30%
64-byte value
Lookups - 3.2 M/s operations
Updates - 2.7 M/s operations
False positive rate: 0.30%

Signed-off-by: Joanne Koong <joannekoong@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211027234504.30744-5-joannekoong@fb.com

selftests/bpf: Support multiple tests per file

Revamp how test discovery works for test_progs and allow multiple test
entries per file. Any global void function with no arguments and
serial_test_ or test_ prefix is considered a test.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211022223228.99920-3-andrii@kernel.org

bpftool: Add install-bin target to install binary only

With "make install", bpftool installs its binary and its bash completion
file. Usually, this is what we want. But a few components in the kernel
repository (namely, BPF iterators and selftests) also install bpftool
locally before using it. In such a case, bash completion is not
necessary and is just a useless build artifact.

Let's add an "install-bin" target to bpftool, to offer a way to install
the binary only.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211007194438.34443-13-quentin@isovalent.com

tools/runqslower: Install libbpf headers when building

API headers from libbpf should not be accessed directly from the
library's source directory. Instead, they should be exported with "make
install_headers". Let's make sure that runqslower installs the
headers properly when building.

We use a libbpf_hdrs target to mark the logical dependency on libbpf's
headers export for a number of object files, even though the headers
should have been exported at this time (since bpftool needs them, and is
required to generate the skeleton or the vmlinux.h).

When descending from a parent Makefile, the specific output directories
for building the library and exporting the headers are configurable with
BPFOBJ_OUTPUT and BPF_DESTDIR, respectively. This is in addition to
OUTPUT, on top of which those variables are constructed by default.

Also adjust the Makefile for the BPF selftests. We pass a number of
variables to the "make" invocation, because we want to point runqslower
to the (target) libbpf shared with other tools, instead of building its
own version. In addition, runqslower relies on (target) bpftool, and we
also want to pass the proper variables to its Makefile so that bpftool
itself reuses the same libbpf.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211007194438.34443-6-quentin@isovalent.com

tools/resolve_btfids: Install libbpf headers when building

API headers from libbpf should not be accessed directly from the
library's source directory. Instead, they should be exported with "make
install_headers". Let's make sure that resolve_btfids installs the
headers properly when building.

When descending from a parent Makefile, the specific output directories
for building the library and exporting the headers are configurable with
LIBBPF_OUT and LIBBPF_DESTDIR, respectively. This is in addition to
OUTPUT, on top of which those variables are constructed by default.

Also adjust the Makefile for the BPF selftests in order to point to the
(target) libbpf shared with other tools, instead of building a version
specific to resolve_btfids. Remove libbpf's order-only dependencies on
the include directories (they are created by libbpf and don't need to
exist beforehand).

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211007194438.34443-5-quentin@isovalent.com

bpftool: Install libbpf headers instead of including the dir

Bpftool relies on libbpf, therefore it relies on a number of headers
from the library and must be linked against the library. The Makefile
for bpftool exposes these objects by adding tools/lib as an include
directory ("-I$(srctree)/tools/lib"). This is a working solution, but
this is not the cleanest one. The risk is to involuntarily include
objects that are not intended to be exposed by the libbpf.

The headers needed to compile bpftool should in fact be "installed" from
libbpf, with its "install_headers" Makefile target. In addition, there
is one header which is internal to the library and not supposed to be
used by external applications, but that bpftool uses anyway.

Adjust the Makefile in order to install the header files properly before
compiling bpftool. Also copy the additional internal header file
(nlattr.h), but call it out explicitly. Build (and install headers) in a
subdirectory under bpftool/ instead of tools/lib/bpf/. When descending
from a parent Makefile, this is configurable by setting the OUTPUT,
LIBBPF_OUTPUT and LIBBPF_DESTDIR variables.

Also adjust the Makefile for BPF selftests, so as to reuse the (host)
libbpf compiled earlier and to avoid compiling a separate version of the
library just for bpftool.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211007194438.34443-4-quentin@isovalent.com

bpf: selftests: Add selftests for module kfunc support

This adds selftests that tests the success and failure path for modules
kfuncs (in presence of invalid kfunc calls) for both libbpf and
gen_loader. It also adds a prog_test kfunc_btf_id_list so that we can
add module BTF ID set from bpf_testmod.

This also introduces a couple of test cases to verifier selftests for
validating whether we get an error or not depending on if invalid kfunc
call remains after elimination of unreachable instructions.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211002011757.311265-10-memxor@gmail.com

tools: Allow specifying base BTF file in resolve_btfids

This commit allows specifying the base BTF for resolving btf id
lists/sets during link time in the resolve_btfids tool. The base BTF is
set to NULL if no path is passed. This allows resolving BTF ids for
module kernel objects.

Also, drop the --no-fail option, as it is only used in case .BTF_ids
section is not present, instead make no-fail the default mode. The long
option name is same as that of pahole.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211002011757.311265-5-memxor@gmail.com

selftests/bpf: Add trace_vprintk test prog

This commit adds a test prog for vprintk which confirms that:
* bpf_trace_vprintk is writing to /sys/kernel/debug/tracing/trace_pipe
* __bpf_vprintk macro works as expected
* >3 args are printed
* bpf_printk w/ 0 format args compiles
* bpf_trace_vprintk call w/ a fmt specifier but NULL fmt data fails

Approach and code are borrowed from trace_printk test.

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210917182911.2426606-9-davemarchevsky@fb.com

libbpf: Add LIBBPF_DEPRECATED_SINCE macro for scheduling API deprecations

Introduce a macro LIBBPF_DEPRECATED_SINCE(major, minor, message) to prepare
the deprecation of two API functions. This macro marks functions as deprecated
when libbpf's version reaches the values passed as an argument.

As part of this change libbpf_version.h header is added with recorded major
(LIBBPF_MAJOR_VERSION) and minor (LIBBPF_MINOR_VERSION) libbpf version macros.
They are now part of libbpf public API and can be relied upon by user code.
libbpf_version.h is installed system-wide along other libbpf public headers.

Due to this new build-time auto-generated header, in-kernel applications
relying on libbpf (resolve_btfids, bpftool, bpf_preload) are updated to
include libbpf's output directory as part of a list of include search paths.
Better fix would be to use libbpf's make_install target to install public API
headers, but that clean up is left out as a future improvement. The build
changes were tested by building kernel (with KBUILD_OUTPUT and O= specified
explicitly), bpftool, libbpf, selftests/bpf, and resolve_btfids builds. No
problems were detected.

Note that because of the constraints of the C preprocessor we have to write
a few lines of macro magic for each version used to prepare deprecation (0.6
for now).

Also, use LIBBPF_DEPRECATED_SINCE() to schedule deprecation of
btf__get_from_id() and btf__load(), which are replaced by
btf__load_from_kernel_by_id() and btf__load_into_kernel(), respectively,
starting from future libbpf v0.6. This is part of libbpf 1.0 effort ([0]).

[0] Closes: https://github.com/libbpf/libbpf/issues/278

Co-developed-by: Quentin Monnet <quentin@isovalent.com>
Co-developed-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210908213226.1871016-1-andrii@kernel.org

selftests, bpf: Fix makefile dependencies on libbpf

When building bpf selftest with make -j, I'm randomly getting build failures
such as this one:

In file included from progs/bpf_flow.c:19:
[...]/tools/testing/selftests/bpf/tools/include/bpf/bpf_helpers.h:11:10: fatal error: 'bpf_helper_defs.h' file not found
#include "bpf_helper_defs.h"
^~~~~~~~~~~~~~~~~~~

The file that fails the build varies between runs but it's always in the
progs/ subdir.

The reason is a missing make dependency on libbpf for the .o files in
progs/. There was a dependency before commit 3ac2e20fba07e but that commit
removed it to prevent unneeded rebuilds. However, that only works if libbpf
has been built already; the 'wildcard' prerequisite does not trigger when
there's no bpf_helper_defs.h generated yet.

Keep the libbpf as an order-only prerequisite to satisfy both goals. It is
always built before the progs/ objects but it does not trigger unnecessary
rebuilds by itself.

Fixes: 3ac2e20fba07e ("selftests/bpf: BPF object files should depend only on libbpf headers")
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/ee84ab66436fba05a197f952af23c98d90eb6243.1632758415.git.jbenc@redhat.com

selftests/bpf: Add missing files required by test_bpftool.sh for installing

test_bpftool.sh relies on bpftool and test_bpftool.py.

'make install' will install bpftool to INSTALL_PATH/bpf/bpftool, and
export it to PATH so that it can be used after installing.

Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210820015556.23276-5-lizhijian@cn.fujitsu.com

selftests/bpf: Move netcnt test under test_progs

Rewrite to skel and ASSERT macros as well while we are at it.

v3:
- replace -f with -A to make it work with busybox ping.
-A is available on both busybox and iputils, from the man page:
On networks with low RTT this mode is essentially equivalent to
flood mode.

v2:
- don't check result of bpf_map__fd (Yonghong Song)
- remove from .gitignore (Andrii Nakryiko)
- move ping_command into network_helpers (Andrii Nakryiko)
- remove assert() (Andrii Nakryiko)

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210804205524.3748709-1-sdf@google.com

selftests/bpf: Add xdp_redirect_multi test

Add a bpf selftest for new helper xdp_redirect_map_multi(). In this
test there are 3 forward groups and 1 exclude group. The test will
redirect each interface's packets to all the interfaces in the forward
group, and exclude the interface in exclude map.

Two maps (DEVMAP, DEVMAP_HASH) and two xdp modes (generic, drive) will
be tested. XDP egress program will also be tested by setting pkt src MAC
to egress interface's MAC address.

For more test details, you can find it in the test script. Here is
the test result.
]# time ./test_xdp_redirect_multi.sh
Pass: xdpgeneric arp(F_BROADCAST) ns1-1
Pass: xdpgeneric arp(F_BROADCAST) ns1-2
Pass: xdpgeneric arp(F_BROADCAST) ns1-3
Pass: xdpgeneric IPv4 (F_BROADCAST|F_EXCLUDE_INGRESS) ns1-1
Pass: xdpgeneric IPv4 (F_BROADCAST|F_EXCLUDE_INGRESS) ns1-2
Pass: xdpgeneric IPv4 (F_BROADCAST|F_EXCLUDE_INGRESS) ns1-3
Pass: xdpgeneric IPv6 (no flags) ns1-1
Pass: xdpgeneric IPv6 (no flags) ns1-2
Pass: xdpdrv arp(F_BROADCAST) ns1-1
Pass: xdpdrv arp(F_BROADCAST) ns1-2
Pass: xdpdrv arp(F_BROADCAST) ns1-3
Pass: xdpdrv IPv4 (F_BROADCAST|F_EXCLUDE_INGRESS) ns1-1
Pass: xdpdrv IPv4 (F_BROADCAST|F_EXCLUDE_INGRESS) ns1-2
Pass: xdpdrv IPv4 (F_BROADCAST|F_EXCLUDE_INGRESS) ns1-3
Pass: xdpdrv IPv6 (no flags) ns1-1
Pass: xdpdrv IPv6 (no flags) ns1-2
Pass: xdpegress mac ns1-2
Pass: xdpegress mac ns1-3
Summary: PASS 18, FAIL 0

real 1m18.321s
user 0m0.123s
sys 0m0.350s

Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20210519090747.1655268-5-liuhangbin@gmail.com

selftests/bpf: Convert test trace_printk to lskel.

Convert test trace_printk to light skeleton to check
rodata support in lskel.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210514003623.28033-22-alexei.starovoitov@gmail.com

selftests/bpf: Convert atomics test to light skeleton.

Convert prog_tests/atomics.c to lskel.h

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210514003623.28033-20-alexei.starovoitov@gmail.com

selftests/bpf: Convert few tests to light skeleton.

Convert few tests that don't use CO-RE to light skeleton.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210514003623.28033-19-alexei.starovoitov@gmail.com

tools: do not include scripts/Kbuild.include

Since commit 57fd251c7896 ("kbuild: split cc-option and friends to
scripts/Makefile.compiler"), some kselftests fail to build.

The tools/ directory opted out Kbuild, and went in a different
direction. People copied scripts and Makefiles to the tools/ directory
to create their own build system.

tools/build/Build.include mimics scripts/Kbuild.include, but some
tool Makefiles include the Kbuild one to import a feature that is
missing in tools/build/Build.include:

- Commit ec04aa3ae87b ("tools/thermal: tmon: use "-fstack-protector"
only if supported") included scripts/Kbuild.include from
tools/thermal/tmon/Makefile to import the cc-option macro.

- Commit c2390f16fc5b ("selftests: kvm: fix for compilers that do
not support -no-pie") included scripts/Kbuild.include from
tools/testing/selftests/kvm/Makefile to import the try-run macro.

- Commit 9cae4ace80ef ("selftests/bpf: do not ignore clang
failures") included scripts/Kbuild.include from
tools/testing/selftests/bpf/Makefile to import the .DELETE_ON_ERROR
target.

- Commit 0695f8bca93e ("selftests/powerpc: Handle Makefile for
unrecognized option") included scripts/Kbuild.include from
tools/testing/selftests/powerpc/pmu/ebb/Makefile to import the
try-run macro.

Copy what they need into tools/build/Build.include, and make them
include it instead of scripts/Kbuild.include.

Link: https://lore.kernel.org/lkml/86dadf33-70f7-a5ac-cb8c-64966d2f45a1@linux.ibm.com/
Fixes: 57fd251c7896 ("kbuild: split cc-option and friends to scripts/Makefile.compiler")
Reported-by: Janosch Frank <frankja@linux.ibm.com>
Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Yonghong Song <yhs@fb.com>

selftests/bpf: Add map linking selftest

Add selftest validating various aspects of statically linking BTF-defined map
definitions. Legacy map definitions do not support extern resolution between
object files. Some of the aspects validated:
- correct resolution of extern maps against concrete map definitions;
- extern maps can currently only specify map type and key/value size and/or
type information;
- weak concrete map definitions are resolved properly.

Static map definitions are not yet supported by libbpf, so they are not
explicitly tested, though manual testing showes that BPF linker handles them
properly.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210423181348.1801389-18-andrii@kernel.org

selftests/bpf: Add global variables linking selftest

Add selftest validating various aspects of statically linking global
variables:
- correct resolution of extern variables across .bss, .data, and .rodata
sections;
- correct handling of weak definitions;
- correct de-duplication of repeating special externs (.kconfig, .ksyms).

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210423181348.1801389-17-andrii@kernel.org

selftests/bpf: Add function linking selftest

Add selftest validating various aspects of statically linking functions:
- no conflicts and correct resolution for name-conflicting static funcs;
- correct resolution of extern functions;
- correct handling of weak functions, both resolution itself and libbpf's
handling of unused weak function that "lost" (it leaves gaps in code with
no ELF symbols);
- correct handling of hidden visibility to turn global function into
"static" for the purpose of BPF verification.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210423181348.1801389-16-andrii@kernel.org

selftests/bpf: Omit skeleton generation for multi-linked BPF object files

Skip generating individual BPF skeletons for files that are supposed to be
linked together to form the final BPF object file. Very often such files are
"incomplete" BPF object files, which will fail libbpf bpf_object__open() step,
if used individually, thus failing BPF skeleton generation. This is by design,
so skip individual BPF skeletons and only validate them as part of their
linked final BPF object file and skeleton.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210423181348.1801389-15-andrii@kernel.org

selftests/bpf: Use -O0 instead of -Og in selftests builds

While -Og is designed to work well with debugger, it's still inferior to -O0
in terms of debuggability experience. It will cause some variables to still be
inlined, it will also prevent single-stepping some statements and otherwise
interfere with debugging experience. So switch to -O0 which turns off any
optimization and provides the best debugging experience.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210423181348.1801389-14-andrii@kernel.org

selftests/bpf: Add docs target as all dependency

Currently docs target is make dependency for TEST_GEN_FILES,
which makes tests to be rebuilt every time you run make.

Adding docs as all target dependency, so when running make
on top of built selftests it will show just:

$ make
make[1]: Nothing to be done for 'docs'.

After cleaning docs, only docs is rebuilt:

$ make docs-clean
CLEAN eBPF_helpers-manpage
CLEAN eBPF_syscall-manpage
$ make
GEN ...selftests/bpf/bpf-helpers.rst
GEN ...selftests/bpf/bpf-helpers.7
GEN ...selftests/bpf/bpf-syscall.rst
GEN ...selftests/bpf/bpf-syscall.2
$ make
make[1]: Nothing to be done for 'docs'.

Fixes: a01d935b2e09 ("tools/bpf: Remove bpf-helpers from bpftool docs")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210420132428.15710-1-jolsa@kernel.org

selftests/bpf: Silence clang compilation warnings

With clang compiler:
make -j60 LLVM=1 LLVM_IAS=1 <=== compile kernel
make -j60 -C tools/testing/selftests/bpf LLVM=1 LLVM_IAS=1
Some linker flags are not used/effective for some binaries and
we have warnings like:
warning: -lelf: 'linker' input unused [-Wunused-command-line-argument]

We also have warnings like:
.../selftests/bpf/prog_tests/ns_current_pid_tgid.c:74:57: note: treat the string as an argument to avoid this
if (CHECK(waitpid(cpid, &wstatus, 0) == -1, "waitpid", strerror(errno)))
^
"%s",
.../selftests/bpf/test_progs.h:129:35: note: expanded from macro 'CHECK'
_CHECK(condition, tag, duration, format)
^
.../selftests/bpf/test_progs.h:108:21: note: expanded from macro '_CHECK'
fprintf(stdout, ##format); \
^
The first warning can be silenced with clang option -Wno-unused-command-line-argument.
For the second warning, source codes are modified as suggested by the compiler
to silence the warning. Since gcc does not support the option
-Wno-unused-command-line-argument and the warning only happens with clang
compiler, the option -Wno-unused-command-line-argument is enabled only when
clang compiler is used.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210413153429.3029377-1-yhs@fb.com

selftests/bpf: Fix test_cpp compilation failure with clang

With clang compiler:
make -j60 LLVM=1 LLVM_IAS=1 <=== compile kernel
make -j60 -C tools/testing/selftests/bpf LLVM=1 LLVM_IAS=1
the test_cpp build failed due to the failure:
warning: treating 'c-header' input as 'c++-header' when in C++ mode, this behavior is deprecated [-Wdeprecated]
clang-13: error: cannot specify -o when generating multiple output files

test_cpp compilation flag looks like:
clang++ -g -Og -rdynamic -Wall -I<...> ... \
-Dbpf_prog_load=bpf_prog_test_load -Dbpf_load_program=bpf_test_load_program \
test_cpp.cpp <...>/test_core_extern.skel.h <...>/libbpf.a <...>/test_stub.o \
-lcap -lelf -lz -lrt -lpthread -o <...>/test_cpp

The clang++ compiler complains the header file in the command line and
also failed the compilation due to this.
Let us remove the header file from the command line which is not intended
any way, and this fixed the compilation problem.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210413153424.3028986-1-yhs@fb.com

selftests/bpf: Add multi-file statically linked BPF object file test

Add Makefile infra to specify multi-file BPF object files (and derivative
skeletons). Add first selftest validating BPF static linker can merge together
successfully two independent BPF object files and resulting object and
skeleton are correct and usable.

Use the same F(F(F(X))) = F(F(X)) identity test on linked object files as for
the case of single BPF object files.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210318194036.3521577-13-andrii@kernel.org

selftests/bpf: Pass all BPF .o's through BPF static linker

Pass all individual BPF object files (generated from progs/*.c) through
`bpftool gen object` command to validate that BPF static linker doesn't
corrupt them.

As an additional sanity checks, validate that passing resulting object files
through linker again results in identical ELF files. Exact same ELF contents
can be guaranteed only after two passes, as after the first pass ELF sections
order changes, and thus .BTF.ext data sections order changes. That, in turn,
means that strings are added into the final BTF string sections in different
order, so .BTF strings data might not be exactly the same. But doing another
round of linking afterwards should result in the identical ELF file, which is
checked with additional `diff` command.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210318194036.3521577-12-andrii@kernel.org

selftests/bpf: Re-generate vmlinux.h and BPF skeletons if bpftool changed

Trigger vmlinux.h and BPF skeletons re-generation if detected that bpftool was
re-compiled. Otherwise full `make clean` is required to get updated skeletons,
if bpftool is modified.

Fixes: acbd06206bbb ("selftests/bpf: Add vmlinux.h selftest exercising tracing of syscalls")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210318194036.3521577-11-andrii@kernel.org

selftests/bpf: Build everything in debug mode

Build selftests, bpftool, and libbpf in debug mode with DWARF data to
facilitate easier debugging.

In terms of impact on building and running selftests. Build is actually faster
now:

BEFORE: make -j60 380.21s user 37.87s system 1466% cpu 28.503 total
AFTER: make -j60 345.47s user 37.37s system 1599% cpu 23.939 total

test_progs runtime seems to be the same:

BEFORE:
real 1m5.139s
user 0m1.600s
sys 0m43.977s

AFTER:
real 1m3.799s
user 0m1.721s
sys 0m42.420s

Huge difference is being able to debug issues throughout test_progs, bpftool,
and libbpf without constantly updating 3 Makefiles by hand (including GDB
seeing the source code without any extra incantations).

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210313210920.1959628-5-andrii@kernel.org

selftests/bpf: Fix typo in Makefile

The selftest build fails when trying to install the scripts:

rsync: [sender] link_stat "tools/testing/selftests/bpf/test_docs_build.sh" failed: No such file or directory (2)

Fix the filename.

Fixes: a01d935b2e09 ("tools/bpf: Remove bpf-helpers from bpftool docs")
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210308182830.155784-1-jean-philippe@linaro.org

tools/bpf: Remove bpf-helpers from bpftool docs

This logic is used for validating the manual pages from selftests, so
move the infra under tools/testing/selftests/bpf/ and rely on selftests
for validation rather than tying it into the bpftool build.

Signed-off-by: Joe Stringer <joe@cilium.io>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20210302171947.2268128-12-joe@cilium.io

selftests/bpf: Copy extras in out-of-srctree builds

Building selftests in a separate directory like this:

make O="$BUILD" -C tools/testing/selftests/bpf

and then running:

cd "$BUILD" && ./test_progs -t btf

causes all the non-flavored btf_dump_test_case_*.c tests to fail,
because these files are not copied to where test_progs expects to find
them.

Fix by not skipping EXT-COPY when the original $(OUTPUT) is not empty
(lib.mk sets it to $(shell pwd) in that case) and using rsync instead
of cp: cp fails because e.g. urandom_read is being copied into itself,
and rsync simply skips such cases. rsync is already used by kselftests
and therefore is not a new dependency.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210224111445.102342-1-iii@linux.ibm.com

selftests/bpf: Integrate the socket_cookie test to test_progs

Currently, the selftest for the BPF socket_cookie helpers is built and
run independently from test_progs. It's easy to forget and hard to
maintain.

This patch moves the socket cookies test into prog_tests/ and vastly
simplifies its logic by:
- rewriting the loading code with BPF skeletons
- rewriting the server/client code with network helpers
- rewriting the cgroup code with test__join_cgroup
- rewriting the error handling code with CHECKs

Signed-off-by: Florent Revest <revest@chromium.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: KP Singh <kpsingh@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210210111406.785541-3-revest@chromium.org

tools: Factor Clang, LLC and LLVM utils definitions

When dealing with BPF/BTF/pahole and DWARF v5 I wanted to build bpftool.

While looking into the source code I found duplicate assignments in misc tools
for the LLVM eco system, e.g. clang and llvm-objcopy.

Move the Clang, LLC and/or LLVM utils definitions to tools/scripts/Makefile.include
file and add missing includes where needed. Honestly, I was inspired by the commit
c8a950d0d3b9 ("tools: Factor HOSTCC, HOSTLD, HOSTAR definitions").

I tested with bpftool and perf on Debian/testing AMD64 and LLVM/Clang v11.1.0-rc1.

Build instructions:

[ make and make-options ]
MAKE="make V=1"
MAKE_OPTS="HOSTCC=clang HOSTCXX=clang++ HOSTLD=ld.lld CC=clang LD=ld.lld LLVM=1 LLVM_IAS=1"
MAKE_OPTS="$MAKE_OPTS PAHOLE=/opt/pahole/bin/pahole"

[ clean-up ]
$MAKE $MAKE_OPTS -C tools/ clean

[ bpftool ]
$MAKE $MAKE_OPTS -C tools/bpf/bpftool/

[ perf ]
PYTHON=python3 $MAKE $MAKE_OPTS -C tools/perf/

I was careful with respecting the user's wish to override custom compiler, linker,
GNU/binutils and/or LLVM utils settings.

Signed-off-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com> # tools/build and tools/perf
Link: https://lore.kernel.org/bpf/20210128015117.20515-1-sedat.dilek@gmail.com

bpf, selftests: Fold test_current_pid_tgid_new_ns into test_progs.

Currently tests for bpf_get_ns_current_pid_tgid() are outside test_progs.
This change folds test cases into test_progs.

Changes from v11:

- Fixed test failure is not detected.
- Removed EXIT(3) call as it will stop test_progs execution.

Signed-off-by: Carlos Neira <cneirabustos@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210114141033.GA17348@localhost
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

bpf: Add tests for new BPF atomic operations

The prog_test that's added depends on Clang/LLVM features added by
Yonghong in commit 286daafd6512 (was https://reviews.llvm.org/D72184).

Note the use of a define called ENABLE_ATOMICS_TESTS: this is used
to:

- Avoid breaking the build for people on old versions of Clang
- Avoid needing separate lists of test objects for no_alu32, where
atomics are not supported even if Clang has the feature.

The atomics_test.o BPF object is built unconditionally both for
test_progs and test_progs-no_alu32. For test_progs, if Clang supports
atomics, ENABLE_ATOMICS_TESTS is defined, so it includes the proper
test code. Otherwise, progs and global vars are defined anyway, as
stubs; this means that the skeleton user code still builds.

The atomics_test.o userspace object is built once and used for both
test_progs and test_progs-no_alu32. A variable called skip_tests is
defined in the BPF object's data section, which tells the userspace
object whether to skip the atomics test.

Signed-off-by: Brendan Jackman <jackmanb@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210114181751.768687-11-jackmanb@google.com

selftests/bpf: Install btf_dump test cases

The btf_dump test cannot access the original source files for comparison
when running the selftests out of tree, causing several failures:

awk: btf_dump_test_case_syntax.c: No such file or directory
...

Add those files to $(TEST_FILES) to have "make install" pick them up.

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210113163319.1516382-6-jean-philippe@linaro.org

selftests/bpf: Fix installation of urandom_read

For out-of-tree builds, $(TEST_CUSTOM_PROGS) require the $(OUTPUT)
prefix, otherwise the kselftest lib doesn't know how to install them:

rsync: [sender] link_stat "tools/testing/selftests/bpf/urandom_read" failed: No such file or directory (2)

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210113163319.1516382-5-jean-philippe@linaro.org

selftests/bpf: Move generated test files to $(TEST_GEN_FILES)

During an out-of-tree build, attempting to install the $(TEST_FILES)
into the $(OUTPUT) directory fails, because the objects were already
generated into $(OUTPUT):

rsync: [sender] link_stat "tools/testing/selftests/bpf/test_lwt_ip_encap.o" failed: No such file or directory (2)
rsync: [sender] link_stat "tools/testing/selftests/bpf/test_tc_edt.o" failed: No such file or directory (2)

Use $(TEST_GEN_FILES) instead.

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210113163319.1516382-4-jean-philippe@linaro.org

selftests/bpf: Fix out-of-tree build

When building out-of-tree, the .skel.h files are generated into the
$(OUTPUT) directory, rather than $(CURDIR). Add $(OUTPUT) to the include
paths.

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210113163319.1516382-3-jean-philippe@linaro.org

selftests/bpf: Enable cross-building

Build bpftool and resolve_btfids using the host toolchain when
cross-compiling, since they are executed during build to generate the
selftests. Add a host build directory in order to build both host and
target version of libbpf. Build host tools using $(HOSTCC) defined in
Makefile.include.

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210113163319.1516382-2-jean-philippe@linaro.org

selftests/bpf: Clarify build error if no vmlinux

If Makefile cannot find any of the vmlinux's in its VMLINUX_BTF_PATHS list,
it tries to run btftool incorrectly, with VMLINUX_BTF unset:

bpftool btf dump file $(VMLINUX_BTF) format c

Such that the keyword 'format' is misinterpreted as the path to vmlinux.
The resulting build error message is fairly cryptic:

GEN vmlinux.h
Error: failed to load BTF from format: No such file or directory

This patch makes the failure reason clearer by yielding this instead:

Makefile:...: *** Cannot find a vmlinux for VMLINUX_BTF at any of
"{paths}". Stop.

Fixes: acbd06206bbb ("selftests/bpf: Add vmlinux.h selftest exercising tracing of syscalls")
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201215182011.15755-1-kamal@canonical.com

selftests/bpf: Drop the need for LLVM's llc

LLC is meant for compiler development and debugging. Consequently, it
exposes many low level options about its backend. To avoid future bugs
introduced by using the raw LLC tool, use clang directly so that all
appropriate options are passed to the back end.

Additionally, simplify the Makefile by removing the
CLANG_NATIVE_BPF_BUILD_RULE as it is not being use, stop passing
dwarfris attr since elfutils/libdw now supports the bpf backend (which
should work with any recent pahole), and stop passing alu32 since
-mcpu=v3 implies alu32.

Signed-off-by: Andrew Delgadillo <adelg@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20201211004344.3355074-1-adelg@google.com

selftests/bpf: fix bpf_testmod.ko recompilation logic

bpf_testmod.ko build rule declared dependency on VMLINUX_BTF, but the variable
itself was initialized after the rule was declared, which often caused
bpf_testmod.ko to not be re-compiled. Fix by moving VMLINUX_BTF determination
sooner.

Also enforce bpf_testmod.ko recompilation when we detect that vmlinux image
changed by removing bpf_testmod/bpf_testmod.ko. This is necessary to generate
correct module's split BTF. Without it, Kbuild's module build logic might
determine that nothing changed on the kernel side and thus bpf_testmod.ko
shouldn't be rebuilt, so won't re-generate module BTF, which often leads to
module's BTF with wrong string offsets against vmlinux BTF. Removing .ko file
forces Kbuild to re-build the module.

Reported-by: Alexei Starovoitov <ast@kernel.org>
Fixes: 9f7fa225894c ("selftests/bpf: Add bpf_testmod kernel module for testing")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20201211015946.4062098-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Drop tcp-{client,server}.py from Makefile

The files don't exist anymore so this breaks generic kselftest builds
when using "make install" or "make gen_tar".

Fixes: 247f0ec361b7 ("selftests/bpf: Drop python client/server in favor of threads")
Signed-off-by: Veronika Kabatova <vkabatov@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20201210120134.2148482-1-vkabatov@redhat.com

selftests/bpf: Xsk selftests - SKB POLL, NOPOLL

Adds following tests:

1. AF_XDP SKB mode
Generic mode XDP is driver independent, used when the driver does
not have support for XDP. Works on any netdevice using sockets and
generic XDP path. XDP hook from netif_receive_skb().
a. nopoll - soft-irq processing
b. poll - using poll() syscall

Signed-off-by: Weqaar Janjua <weqaar.a.janjua@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Yonghong Song <yhs@fb.com>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Link: https://lore.kernel.org/bpf/20201207215333.11586-3-weqaar.a.janjua@intel.com

selftests/bpf: Xsk selftests framework

This patch adds AF_XDP selftests framework under selftests/bpf.

Topology:
---------
----------- -----------
| xskX | --------- | xskY |
----------- | -----------
| | |
----------- | ----------
| vethX | --------- | vethY |
----------- peer ----------
| | |
namespaceX | namespaceY

Prerequisites setup by script test_xsk.sh:

Set up veth interfaces as per the topology shown ^^:
* setup two veth interfaces and one namespace
** veth<xxxx> in root namespace
** veth<yyyy> in af_xdp<xxxx> namespace
** namespace af_xdp<xxxx>
* create a spec file veth.spec that includes this run-time configuration
*** xxxx and yyyy are randomly generated 4 digit numbers used to avoid
conflict with any existing interface
* tests the veth and xsk layers of the topology

Signed-off-by: Weqaar Janjua <weqaar.a.janjua@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Yonghong Song <yhs@fb.com>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Link: https://lore.kernel.org/bpf/20201207215333.11586-2-weqaar.a.janjua@intel.com

selftests/bpf: Add bpf_testmod kernel module for testing

Add bpf_testmod module, which is conceptually out-of-tree module and provides
ways for selftests/bpf to test various kernel module-related functionality:
raw tracepoint, fentry/fexit/fmod_ret, etc. This module will be auto-loaded by
test_progs test runner and expected by some of selftests to be present and
loaded.

Pahole currently isn't able to generate BTF for static functions in kernel
modules, so make sure traced function is global.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20201203204634.1325171-7-andrii@kernel.org

bpf: Fix cold build of test_progs-no_alu32

This object lives inside the trunner output dir,
i.e. tools/testing/selftests/bpf/no_alu32/btf_data.o

At some point it gets copied into the parent directory during another
part of the build, but that doesn't happen when building
test_progs-no_alu32 from clean.

Signed-off-by: Brendan Jackman <jackmanb@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/bpf/20201203120850.859170-1-jackmanb@google.com

selftests/bpf: Fix flavored variants of test_ima

Flavored variants of test_progs (e.g. test_progs-no_alu32) change their
working directory to the corresponding subdirectory (e.g. no_alu32).
Since the setup script required by test_ima (ima_setup.sh) is not
mentioned in the dependencies, it does not get copied to these
subdirectories and causes flavored variants of test_ima to fail.

Adding the script to TRUNNER_EXTRA_FILES ensures that the file is also
copied to the subdirectories for the flavored variants of test_progs.

Fixes: 34b82d3ac105 ("bpf: Add a selftest for bpf_ima_inode_hash")
Reported-by: Yonghong Song <yhs@fb.com>
Suggested-by: Yonghong Song <yhs@fb.com>
Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20201126184946.1708213-1-kpsingh@chromium.org

selftests/bpf: Fix broken riscv build

The selftests/bpf Makefile includes system include directories from
the host, when building BPF programs. On RISC-V glibc requires that
__riscv_xlen is defined. This is not the case for "clang -target bpf",
which messes up __WORDSIZE (errno.h -> ... -> wordsize.h) and breaks
the build.

By explicitly defining __risc_xlen correctly for riscv, we can
workaround this.

Fixes: 167381f3eac0 ("selftests/bpf: Makefile fix "missing" headers on build with -idirafter")
Signed-off-by: Björn Töpel <bjorn.topel@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Luke Nelson <luke.r.nels@gmail.com>
Link: https://lore.kernel.org/bpf/20201118071640.83773-2-bjorn.topel@gmail.com

selftests/bpf: Add checking of raw type dump in BTF writer APIs selftests

Add re-usable btf_helpers.{c,h} to provide BTF-related testing routines. Start
with adding a raw BTF dumping helpers.

Raw BTF dump is the most succinct and at the same time a very human-friendly
way to validate exact contents of BTF types. Cross-validate raw BTF dump and
writable BTF in a single selftest. Raw type dump checks also serve as a good
self-documentation.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201105043402.2530976-7-andrii@kernel.org

selftests/bpf: Move test_tcppbf_user into test_progs

Recently a bug was missed due to the fact that test_tcpbpf_user is not a
part of test_progs. In order to prevent similar issues in the future move
the test functionality into test_progs. By doing this we can make certain
that it is a part of standard testing and will not be overlooked.

As a part of moving the functionality into test_progs it is necessary to
integrate with the test_progs framework and to drop any redundant code.
This patch:
1. Cleans up the include headers
2. Dropped a duplicate definition of bpf_find_map
3. Switched over to using test_progs specific cgroup functions
4. Renamed main to test_tcpbpf_user
5. Dropped return value in favor of CHECK_FAIL to check for errors

The general idea is that I wanted to keep the changes as small as possible
while moving the file into the test_progs framework. The follow-on patches
are meant to clean up the remaining issues such as the use of CHECK_FAIL.

Signed-off-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/160443928881.1086697.17661359319919165370.stgit@localhost.localdomain

kbuild: explicitly specify the build id style

ld's --build-id defaults to "sha1" style, while lld defaults to "fast".
The build IDs are very different between the two, which may confuse
programs that reference them.

Signed-off-by: Bill Wendling <morbo@google.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

bpf: selftest: Move sock_fields test into test_progs

This is a mechanical change to
1. move test_sock_fields.c to prog_tests/sock_fields.c
2. rename progs/test_sock_fields_kern.c to progs/test_sock_fields.c

Minimal change is made to the code itself. Next patch will make
changes to use new ways of writing test, e.g. use skel and global
variables.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200925000427.3857814-1-kafai@fb.com

selftests/bpf: Merge most of test_btf into test_progs

Merge 183 tests from test_btf into test_progs framework to be exercised
regularly. All the test_btf tests that were moved are modeled as proper
sub-tests in test_progs framework for ease of debugging and reporting.

No functional or behavioral changes were intended, I tried to preserve
original behavior as much as possible. E.g., `test_progs -v` will activate
"always_log" flag to emit BTF validation log.

The only difference is in reducing the max_entries limit for pretty-printing
tests from (128 * 1024) to just 128 to reduce tests running time without
reducing the coverage.

Example test run:

$ sudo ./test_progs -n 8
...
#8 btf:OK
Summary: 1/183 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200916004819.3767489-1-andriin@fb.com

selftests/bpf: Test load and dump metadata with btftool and skel

This is a simple test to check that loading and dumping metadata
in btftool works, whether or not metadata contents are used by the
program.

A C test is also added to make sure the skeleton code can read the
metadata values.

Signed-off-by: YiFei Zhu <zhuyifei@google.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Cc: YiFei Zhu <zhuyifei1999@gmail.com>
Link: https://lore.kernel.org/bpf/20200915234543.3220146-6-sdf@google.com

selftests, bpftool: Add bpftool (and eBPF helpers) documentation build

eBPF selftests include a script to check that bpftool builds correctly
with different command lines. Let's add one build for bpftool's
documentation so as to detect errors or warning reported by rst2man when
compiling the man pages. Also add a build to the selftests Makefile to
make sure we build bpftool documentation along with bpftool when
building the selftests.

This also builds and checks warnings for the man page for eBPF helpers,
which is built along bpftool's documentation.

This change adds rst2man as a dependency for selftests (it comes with
Python's "docutils").

v2:
- Use "--exit-status=1" option for rst2man instead of counting lines
from stderr.
- Also build bpftool as part as the selftests build (and not only when
the tests are actually run).

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200909162251.15498-3-quentin@isovalent.com

selftests/bpf: BPF object files should depend only on libbpf headers

There is no need to re-build BPF object files if any of the sources of libbpf
change. So record more precise dependency only on libbpf/bpf_*.h headers. This
eliminates unnecessary re-builds.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200820231250.1293069-2-andriin@fb.com

selftests/bpf: Remove test_align leftovers

Calling generic selftests "make install" fails as rsync expects all
files from TEST_GEN_PROGS to be present. The binary is not generated
anymore (commit 3b09d27cc93d) so we can safely remove it from there
and also from gitignore.

Fixes: 3b09d27cc93d ("selftests/bpf: Move test_align under test_progs")
Signed-off-by: Veronika Kabatova <vkabatov@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Link: https://lore.kernel.org/bpf/20200819160710.1345956-1-vkabatov@redhat.com

selftests/bpf: Fix silent Makefile output

99aacebecb75 ("selftests: do not use .ONESHELL") removed .ONESHELL, which
changes how Makefile "silences" multi-command target recipes. selftests/bpf's
Makefile relied (a somewhat unknowingly) on .ONESHELL behavior of silencing
all commands within the recipe if the first command contains @ symbol.
Removing .ONESHELL exposed this hack.

This patch fixes the issue by explicitly silencing each command with $(Q).

Also explicitly define fallback rule for building *.o from *.c, instead of
relying on non-silent inherited rule. This was causing a non-silent output for
bench.o object file.

Fixes: 92f7440ecc93 ("selftests/bpf: More succinct Makefile output")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200807033058.848677-1-andriin@fb.com

selftests/bpf: Prevent runqslower from racing on building bpftool

runqslower's Makefile is building/installing bpftool into
$(OUTPUT)/sbin/bpftool, which coincides with $(DEFAULT_BPFTOOL). In practice
this means that often when building selftests from scratch (after `make
clean`), selftests are racing with runqslower to simultaneously build bpftool
and one of the two processes fail due to file being busy. Prevent this race by
explicitly order-depending on $(BPFTOOL_DEFAULT).

Fixes: a2c9652f751e ("selftests: Refactor build to remove tools/lib/bpf from include path")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200805004757.2960750-1-andriin@fb.com

selftests/bpf: Add test for resolve_btfids

Adding resolve_btfids test under test_progs suite.

It's possible to use btf_ids.h header and its logic in
user space application, so we can add easy test for it.

The test defines BTF_ID_LIST and checks it gets properly
resolved.

For this reason the test_progs binary (and other binaries
that use TRUNNER* macros) is processed with resolve_btfids
tool, which resolves BTF IDs in .BTF_ids section. The BTF
data are taken from btf_data.o object rceated from
progs/btf_data.c.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200711215329.41165-10-jolsa@kernel.org

selftests/bpf: Allow substituting custom vmlinux.h for selftests build

Similarly to bpftool Makefile, allow to specify custom location of vmlinux.h
to be used during the build. This allows simpler testing setups with
checked-in pre-generated vmlinux.h.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200630004759.521530-2-andriin@fb.com

selftests/bpf: Add a default $(CXX) value

When using make kselftest TARGETS=bpf, tools/bpf is built with
MAKEFLAGS=rR, which causes $(CXX) to be undefined, which in turn causes
the build to fail with

CXX test_cpp
/bin/sh: 2: g: not found

Fix by adding a default $(CXX) value, like tools/build/feature/Makefile
already does.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200602175649.2501580-3-iii@linux.ibm.com

bpf: Add BPF ringbuf and perf buffer benchmarks

Extend bench framework with ability to have benchmark-provided child argument
parser for custom benchmark-specific parameters. This makes bench generic code
modular and independent from any specific benchmark.

Also implement a set of benchmarks for new BPF ring buffer and existing perf
buffer. 4 benchmarks were implemented: 2 variations for each of BPF ringbuf
and perfbuf:,
- rb-libbpf utilizes stock libbpf ring_buffer manager for reading data;
- rb-custom implements custom ring buffer setup and reading code, to
eliminate overheads inherent in generic libbpf code due to callback
functions and the need to update consumer position after each consumed
record, instead of batching updates (due to pessimistic assumption that
user callback might take long time and thus could unnecessarily hold ring
buffer space for too long);
- pb-libbpf uses stock libbpf perf_buffer code with all the default
settings, though uses higher-performance raw event callback to minimize
unnecessary overhead;
- pb-custom implements its own custom consumer code to minimize any possible
overhead of generic libbpf implementation and indirect function calls.

All of the test support default, no data notification skipped, mode, as well
as sampled mode (with --rb-sampled flag), which allows to trigger epoll
notification less frequently and reduce overhead. As will be shown, this mode
is especially critical for perf buffer, which suffers from high overhead of
wakeups in kernel.

Otherwise, all benchamrks implement similar way to generate a batch of records
by using fentry/sys_getpgid BPF program, which pushes a bunch of records in
a tight loop and records number of successful and dropped samples. Each record
is a small 8-byte integer, to minimize the effect of memory copying with
bpf_perf_event_output() and bpf_ringbuf_output().

Benchmarks that have only one producer implement optional back-to-back mode,
in which record production and consumption is alternating on the same CPU.
This is the highest-throughput happy case, showing ultimate performance
achievable with either BPF ringbuf or perfbuf.

All the below scenarios are implemented in a script in
benchs/run_bench_ringbufs.sh. Tests were performed on 28-core/56-thread
Intel Xeon CPU E5-2680 v4 @ 2.40GHz CPU.

Single-producer, parallel producer
==================================
rb-libbpf 12.054 ± 0.320M/s (drops 0.000 ± 0.000M/s)
rb-custom 8.158 ± 0.118M/s (drops 0.001 ± 0.003M/s)
pb-libbpf 0.931 ± 0.007M/s (drops 0.000 ± 0.000M/s)
pb-custom 0.965 ± 0.003M/s (drops 0.000 ± 0.000M/s)

Single-producer, parallel producer, sampled notification
========================================================
rb-libbpf 11.563 ± 0.067M/s (drops 0.000 ± 0.000M/s)
rb-custom 15.895 ± 0.076M/s (drops 0.000 ± 0.000M/s)
pb-libbpf 9.889 ± 0.032M/s (drops 0.000 ± 0.000M/s)
pb-custom 9.866 ± 0.028M/s (drops 0.000 ± 0.000M/s)

Single producer on one CPU, consumer on another one, both running at full
speed. Curiously, rb-libbpf has higher throughput than objectively faster (due
to more lightweight consumer code path) rb-custom. It appears that faster
consumer causes kernel to send notifications more frequently, because consumer
appears to be caught up more frequently. Performance of perfbuf suffers from
default "no sampling" policy and huge overhead that causes.

In sampled mode, rb-custom is winning very significantly eliminating too
frequent in-kernel wakeups, the gain appears to be more than 2x.

Perf buffer achieves even more impressive wins, compared to stock perfbuf
settings, with 10x improvements in throughput with 1:500 sampling rate. The
trade-off is that with sampling, application might not get next X events until
X+1st arrives, which is not always acceptable. With steady influx of events,
though, this shouldn't be a problem.

Overall, single-producer performance of ring buffers seems to be better no
matter the sampled/non-sampled modes, but it especially beats ring buffer
without sampling due to its adaptive notification approach.

Single-producer, back-to-back mode
==================================
rb-libbpf 15.507 ± 0.247M/s (drops 0.000 ± 0.000M/s)
rb-libbpf-sampled 14.692 ± 0.195M/s (drops 0.000 ± 0.000M/s)
rb-custom 21.449 ± 0.157M/s (drops 0.000 ± 0.000M/s)
rb-custom-sampled 20.024 ± 0.386M/s (drops 0.000 ± 0.000M/s)
pb-libbpf 1.601 ± 0.015M/s (drops 0.000 ± 0.000M/s)
pb-libbpf-sampled 8.545 ± 0.064M/s (drops 0.000 ± 0.000M/s)
pb-custom 1.607 ± 0.022M/s (drops 0.000 ± 0.000M/s)
pb-custom-sampled 8.988 ± 0.144M/s (drops 0.000 ± 0.000M/s)

Here we test a back-to-back mode, which is arguably best-case scenario both
for BPF ringbuf and perfbuf, because there is no contention and for ringbuf
also no excessive notification, because consumer appears to be behind after
the first record. For ringbuf, custom consumer code clearly wins with 21.5 vs
16 million records per second exchanged between producer and consumer. Sampled
mode actually hurts a bit due to slightly slower producer logic (it needs to
fetch amount of data available to decide whether to skip or force notification).

Perfbuf with wakeup sampling gets 5.5x throughput increase, compared to
no-sampling version. There also doesn't seem to be noticeable overhead from
generic libbpf handling code.

Perfbuf back-to-back, effect of sample rate
===========================================
pb-sampled-1 1.035 ± 0.012M/s (drops 0.000 ± 0.000M/s)
pb-sampled-5 3.476 ± 0.087M/s (drops 0.000 ± 0.000M/s)
pb-sampled-10 5.094 ± 0.136M/s (drops 0.000 ± 0.000M/s)
pb-sampled-25 7.118 ± 0.153M/s (drops 0.000 ± 0.000M/s)
pb-sampled-50 8.169 ± 0.156M/s (drops 0.000 ± 0.000M/s)
pb-sampled-100 8.887 ± 0.136M/s (drops 0.000 ± 0.000M/s)
pb-sampled-250 9.180 ± 0.209M/s (drops 0.000 ± 0.000M/s)
pb-sampled-500 9.353 ± 0.281M/s (drops 0.000 ± 0.000M/s)
pb-sampled-1000 9.411 ± 0.217M/s (drops 0.000 ± 0.000M/s)
pb-sampled-2000 9.464 ± 0.167M/s (drops 0.000 ± 0.000M/s)
pb-sampled-3000 9.575 ± 0.273M/s (drops 0.000 ± 0.000M/s)

This benchmark shows the effect of event sampling for perfbuf. Back-to-back
mode for highest throughput. Just doing every 5th record notification gives
3.5x speed up. 250-500 appears to be the point of diminishing return, with
almost 9x speed up. Most benchmarks use 500 as the default sampling for pb-raw
and pb-custom.

Ringbuf back-to-back, effect of sample rate
===========================================
rb-sampled-1 1.106 ± 0.010M/s (drops 0.000 ± 0.000M/s)
rb-sampled-5 4.746 ± 0.149M/s (drops 0.000 ± 0.000M/s)
rb-sampled-10 7.706 ± 0.164M/s (drops 0.000 ± 0.000M/s)
rb-sampled-25 12.893 ± 0.273M/s (drops 0.000 ± 0.000M/s)
rb-sampled-50 15.961 ± 0.361M/s (drops 0.000 ± 0.000M/s)
rb-sampled-100 18.203 ± 0.445M/s (drops 0.000 ± 0.000M/s)
rb-sampled-250 19.962 ± 0.786M/s (drops 0.000 ± 0.000M/s)
rb-sampled-500 20.881 ± 0.551M/s (drops 0.000 ± 0.000M/s)
rb-sampled-1000 21.317 ± 0.532M/s (drops 0.000 ± 0.000M/s)
rb-sampled-2000 21.331 ± 0.535M/s (drops 0.000 ± 0.000M/s)
rb-sampled-3000 21.688 ± 0.392M/s (drops 0.000 ± 0.000M/s)

Similar benchmark for ring buffer also shows a great advantage (in terms of
throughput) of skipping notifications. Skipping every 5th one gives 4x boost.
Also similar to perfbuf case, 250-500 seems to be the point of diminishing
returns, giving roughly 20x better results.

Keep in mind, for this test, notifications are controlled manually with
BPF_RB_NO_WAKEUP and BPF_RB_FORCE_WAKEUP. As can be seen from previous
benchmarks, adaptive notifications based on consumer's positions provides same
(or even slightly better due to simpler load generator on BPF side) benefits in
favorable back-to-back scenario. Over zealous and fast consumer, which is
almost always caught up, will make thoughput numbers smaller. That's the case
when manual notification control might prove to be extremely beneficial.

Ringbuf back-to-back, reserve+commit vs output
==============================================
reserve 22.819 ± 0.503M/s (drops 0.000 ± 0.000M/s)
output 18.906 ± 0.433M/s (drops 0.000 ± 0.000M/s)

Ringbuf sampled, reserve+commit vs output
=========================================
reserve-sampled 15.350 ± 0.132M/s (drops 0.000 ± 0.000M/s)
output-sampled 14.195 ± 0.144M/s (drops 0.000 ± 0.000M/s)

BPF ringbuf supports two sets of APIs with various usability and performance
tradeoffs: bpf_ringbuf_reserve()+bpf_ringbuf_commit() vs bpf_ringbuf_output().
This benchmark clearly shows superiority of reserve+commit approach, despite
using a small 8-byte record size.

Single-producer, consumer/producer competing on the same CPU, low batch count
=============================================================================
rb-libbpf 3.045 ± 0.020M/s (drops 3.536 ± 0.148M/s)
rb-custom 3.055 ± 0.022M/s (drops 3.893 ± 0.066M/s)
pb-libbpf 1.393 ± 0.024M/s (drops 0.000 ± 0.000M/s)
pb-custom 1.407 ± 0.016M/s (drops 0.000 ± 0.000M/s)

This benchmark shows one of the worst-case scenarios, in which producer and
consumer do not coordinate *and* fight for the same CPU. No batch count and
sampling settings were able to eliminate drops for ringbuffer, producer is
just too fast for consumer to keep up. But ringbuf and perfbuf still able to
pass through quite a lot of messages, which is more than enough for a lot of
applications.

Ringbuf, multi-producer contention
==================================
rb-libbpf nr_prod 1 10.916 ± 0.399M/s (drops 0.000 ± 0.000M/s)
rb-libbpf nr_prod 2 4.931 ± 0.030M/s (drops 0.000 ± 0.000M/s)
rb-libbpf nr_prod 3 4.880 ± 0.006M/s (drops 0.000 ± 0.000M/s)
rb-libbpf nr_prod 4 3.926 ± 0.004M/s (drops 0.000 ± 0.000M/s)
rb-libbpf nr_prod 8 4.011 ± 0.004M/s (drops 0.000 ± 0.000M/s)
rb-libbpf nr_prod 12 3.967 ± 0.016M/s (drops 0.000 ± 0.000M/s)
rb-libbpf nr_prod 16 2.604 ± 0.030M/s (drops 0.001 ± 0.002M/s)
rb-libbpf nr_prod 20 2.233 ± 0.003M/s (drops 0.000 ± 0.000M/s)
rb-libbpf nr_prod 24 2.085 ± 0.015M/s (drops 0.000 ± 0.000M/s)
rb-libbpf nr_prod 28 2.055 ± 0.004M/s (drops 0.000 ± 0.000M/s)
rb-libbpf nr_prod 32 1.962 ± 0.004M/s (drops 0.000 ± 0.000M/s)
rb-libbpf nr_prod 36 2.089 ± 0.005M/s (drops 0.000 ± 0.000M/s)
rb-libbpf nr_prod 40 2.118 ± 0.006M/s (drops 0.000 ± 0.000M/s)
rb-libbpf nr_prod 44 2.105 ± 0.004M/s (drops 0.000 ± 0.000M/s)
rb-libbpf nr_prod 48 2.120 ± 0.058M/s (drops 0.000 ± 0.001M/s)
rb-libbpf nr_prod 52 2.074 ± 0.024M/s (drops 0.007 ± 0.014M/s)

Ringbuf uses a very short-duration spinlock during reservation phase, to check
few invariants, increment producer count and set record header. This is the
biggest point of contention for ringbuf implementation. This benchmark
evaluates the effect of multiple competing writers on overall throughput of
a single shared ringbuffer.

Overall throughput drops almost 2x when going from single to two
highly-contended producers, gradually dropping with additional competing
producers. Performance drop stabilizes at around 20 producers and hovers
around 2mln even with 50+ fighting producers, which is a 5x drop compared to
non-contended case. Good kernel implementation in kernel helps maintain decent
performance here.

Note, that in the intended real-world scenarios, it's not expected to get even
close to such a high levels of contention. But if contention will become
a problem, there is always an option of sharding few ring buffers across a set
of CPUs.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200529075424.3139988-5-andriin@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftest/bpf: Add BPF triggering benchmark

It is sometimes desirable to be able to trigger BPF program from user-space
with minimal overhead. sys_enter would seem to be a good candidate, yet in
a lot of cases there will be a lot of noise from syscalls triggered by other
processes on the system. So while searching for low-overhead alternative, I've
stumbled upon getpgid() syscall, which seems to be specific enough to not
suffer from accidental syscall by other apps.

This set of benchmarks compares tp, raw_tp w/ filtering by syscall ID, kprobe,
fentry and fmod_ret with returning error (so that syscall would not be
executed), to determine the lowest-overhead way. Here are results on my
machine (using benchs/run_bench_trigger.sh script):

base : 9.200 ± 0.319M/s
tp : 6.690 ± 0.125M/s
rawtp : 8.571 ± 0.214M/s
kprobe : 6.431 ± 0.048M/s
fentry : 8.955 ± 0.241M/s
fmodret : 8.903 ± 0.135M/s

So it seems like fmodret doesn't give much benefit for such lightweight
syscall. Raw tracepoint is pretty decent despite additional filtering logic,
but it will be called for any other syscall in the system, which rules it out.
Fentry, though, seems to be adding the least amoung of overhead and achieves
97.3% of performance of baseline no-BPF-attached syscall.

Using getpgid() seems to be preferable to set_task_comm() approach from
test_overhead, as it's about 2.35x faster in a baseline performance.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200512192445.2351848-5-andriin@fb.com

selftest/bpf: Fmod_ret prog and implement test_overhead as part of bench

Add fmod_ret BPF program to existing test_overhead selftest. Also re-implement
user-space benchmarking part into benchmark runner to compare results. Results
with ./bench are consistently somewhat lower than test_overhead's, but relative
performance of various types of BPF programs stay consisten (e.g., kretprobe is
noticeably slower). This slowdown seems to be coming from the fact that
test_overhead is single-threaded, while benchmark always spins off at least
one thread for producer. This has been confirmed by hacking multi-threaded
test_overhead variant and also single-threaded bench variant. Resutls are
below. run_bench_rename.sh script from benchs/ subdirectory was used to
produce results for ./bench.

Single-threaded implementations
===============================

/* bench: single-threaded, atomics */
base : 4.622 ± 0.049M/s
kprobe : 3.673 ± 0.052M/s
kretprobe : 2.625 ± 0.052M/s
rawtp : 4.369 ± 0.089M/s
fentry : 4.201 ± 0.558M/s
fexit : 4.309 ± 0.148M/s
fmodret : 4.314 ± 0.203M/s

/* selftest: single-threaded, no atomics */
task_rename base 4555K events per sec
task_rename kprobe 3643K events per sec
task_rename kretprobe 2506K events per sec
task_rename raw_tp 4303K events per sec
task_rename fentry 4307K events per sec
task_rename fexit 4010K events per sec
task_rename fmod_ret 3984K events per sec

Multi-threaded implementations
==============================

/* bench: multi-threaded w/ atomics */
base : 3.910 ± 0.023M/s
kprobe : 3.048 ± 0.037M/s
kretprobe : 2.300 ± 0.015M/s
rawtp : 3.687 ± 0.034M/s
fentry : 3.740 ± 0.087M/s
fexit : 3.510 ± 0.009M/s
fmodret : 3.485 ± 0.050M/s

/* selftest: multi-threaded w/ atomics */
task_rename base 3872K events per sec
task_rename kprobe 3068K events per sec
task_rename kretprobe 2350K events per sec
task_rename raw_tp 3731K events per sec
task_rename fentry 3639K events per sec
task_rename fexit 3558K events per sec
task_rename fmod_ret 3511K events per sec

/* selftest: multi-threaded, no atomics */
task_rename base 3945K events per sec
task_rename kprobe 3298K events per sec
task_rename kretprobe 2451K events per sec
task_rename raw_tp 3718K events per sec
task_rename fentry 3782K events per sec
task_rename fexit 3543K events per sec
task_rename fmod_ret 3526K events per sec

Note that the fact that ./bench benchmark always uses atomic increments for
counting, while test_overhead doesn't, doesn't influence test results all that
much.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200512192445.2351848-4-andriin@fb.com

selftests/bpf: Add benchmark runner infrastructure

While working on BPF ringbuf implementation, testing, and benchmarking, I've
developed a pretty generic and modular benchmark runner, which seems to be
generically useful, as I've already used it for one more purpose (testing
fastest way to trigger BPF program, to minimize overhead of in-kernel code).

This patch adds generic part of benchmark runner and sets up Makefile for
extending it with more sets of benchmarks.

Benchmarker itself operates by spinning up specified number of producer and
consumer threads, setting up interval timer sending SIGALARM signal to
application once a second. Every second, current snapshot with hits/drops
counters are collected and stored in an array. Drops are useful for
producer/consumer benchmarks in which producer might overwhelm consumers.

Once test finishes after given amount of warm-up and testing seconds, mean and
stddev are calculated (ignoring warm-up results) and is printed out to stdout.
This setup seems to give consistent and accurate results.

To validate behavior, I added two atomic counting tests: global and local.
For global one, all the producer threads are atomically incrementing same
counter as fast as possible. This, of course, leads to huge drop of
performance once there is more than one producer thread due to CPUs fighting
for the same memory location.

Local counting, on the other hand, maintains one counter per each producer
thread, incremented independently. Once per second, all counters are read and
added together to form final "counting throughput" measurement. As expected,
such setup demonstrates linear scalability with number of producers (as long
as there are enough physical CPU cores, of course). See example output below.
Also, this setup can nicely demonstrate disastrous effects of false sharing,
if care is not taken to take those per-producer counters apart into
independent cache lines.

Demo output shows global counter first with 1 producer, then with 4. Both
total and per-producer performance significantly drop. The last run is local
counter with 4 producers, demonstrating near-perfect scalability.

$ ./bench -a -w1 -d2 -p1 count-global
Setting up benchmark 'count-global'...
Benchmark 'count-global' started.
Iter 0 ( 24.822us): hits 148.179M/s (148.179M/prod), drops 0.000M/s
Iter 1 ( 37.939us): hits 149.308M/s (149.308M/prod), drops 0.000M/s
Iter 2 (-10.774us): hits 150.717M/s (150.717M/prod), drops 0.000M/s
Iter 3 ( 3.807us): hits 151.435M/s (151.435M/prod), drops 0.000M/s
Summary: hits 150.488 ± 1.079M/s (150.488M/prod), drops 0.000 ± 0.000M/s

$ ./bench -a -w1 -d2 -p4 count-global
Setting up benchmark 'count-global'...
Benchmark 'count-global' started.
Iter 0 ( 60.659us): hits 53.910M/s ( 13.477M/prod), drops 0.000M/s
Iter 1 (-17.658us): hits 53.722M/s ( 13.431M/prod), drops 0.000M/s
Iter 2 ( 5.865us): hits 53.495M/s ( 13.374M/prod), drops 0.000M/s
Iter 3 ( 0.104us): hits 53.606M/s ( 13.402M/prod), drops 0.000M/s
Summary: hits 53.608 ± 0.113M/s ( 13.402M/prod), drops 0.000 ± 0.000M/s

$ ./bench -a -w1 -d2 -p4 count-local
Setting up benchmark 'count-local'...
Benchmark 'count-local' started.
Iter 0 ( 23.388us): hits 640.450M/s (160.113M/prod), drops 0.000M/s
Iter 1 ( 2.291us): hits 605.661M/s (151.415M/prod), drops 0.000M/s
Iter 2 ( -6.415us): hits 607.092M/s (151.773M/prod), drops 0.000M/s
Iter 3 ( -1.361us): hits 601.796M/s (150.449M/prod), drops 0.000M/s
Summary: hits 604.849 ± 2.739M/s (151.212M/prod), drops 0.000 ± 0.000M/s

Benchmark runner supports setting thread affinity for producer and consumer
threads. You can use -a flag for default CPU selection scheme, where first
consumer gets CPU #0, next one gets CPU #1, and so on. Then producer threads
pick up next CPU and increment one-by-one as well. But user can also specify
a set of CPUs independently for producers and consumers with --prod-affinity
1,2-10,15 and --cons-affinity <set-of-cpus>. The latter allows to force
producers and consumers to share same set of CPUs, if necessary.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200512192445.2351848-3-andriin@fb.com

selftests/bpf: Extract parse_num_list into generic testing_helpers.c

Add testing_helpers.c, which will contain generic helpers for test runners and
tests needing some common generic functionality, like parsing a set of
numbers.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200512192445.2351848-2-andriin@fb.com

selftests/bpf: Install generated test progs

Before commit 74b5a5968fe8 ("selftests/bpf: Replace test_progs and
test_maps w/ general rule") selftests/bpf used generic install
target from selftests/lib.mk to install generated bpf test progs
by mentioning them in TEST_GEN_FILES variable.

Take that functionality back.

Fixes: 74b5a5968fe8 ("selftests/bpf: Replace test_progs and test_maps w/ general rule")
Signed-off-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200513021722.7787-1-yauheni.kaliuta@redhat.com

selftests/bpf: Generalize helpers to control background listener

Move the following routines that let us start a background listener
thread and connect to a server by fd to the test_prog:
* start_server - socket+bind+listen
* connect_to_fd - connect to the server identified by fd

These will be used in the next commit.

Also, extend these helpers to support AF_INET6 and accept the family
as an argument.

v5:
* drop pthread.h (Martin KaFai Lau)
* add SO_SNDTIMEO (Martin KaFai Lau)

v4:
* export extra helper to start server without a thread (Martin KaFai Lau)
* tcp_rtt is no longer starting background thread (Martin KaFai Lau)

v2:
* put helpers into network_helpers.c (Andrii Nakryiko)

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200508174611.228805-2-sdf@google.com

selftests/bpf: Use SOCKMAP for server sockets in bpf_sk_assign test

Update bpf_sk_assign test to fetch the server socket from SOCKMAP, now that
map lookup from BPF in SOCKMAP is enabled. This way the test TC BPF program
doesn't need to know what address server socket is bound to.

Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200429181154.479310-4-jakub@cloudflare.com

selftests/bpf: Convert test_hashmap into test_progs test

Fold stand-alone test_hashmap test into test_progs.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200429012111.277390-4-andriin@fb.com

selftests/bpf: Add SAN_CFLAGS param to selftests build to allow sanitizers

Add ability to specify extra compiler flags with SAN_CFLAGS for compilation of
all user-space C files. This allows to build all of selftest programs with,
e.g., custom sanitizer flags, without requiring support for such sanitizers
from anyone compiling selftest/bpf.

As an example, to compile everything with AddressSanitizer, one would do:

$ make clean && make SAN_CFLAGS="-fsanitize=address"

For AddressSanitizer to work, one needs appropriate libasan shared library
installed in the system, with version of libasan matching what GCC links
against. E.g., GCC8 needs libasan5, while GCC7 uses libasan4.

For CentOS 7, to build everything successfully one would need to:
$ sudo yum install devtoolset-8-gcc devtoolset-libasan-devel
$ scl enable devtoolset-8 bash # set up environment

For Arch Linux to run selftests, one would need to install gcc-libs package to
get libasan.so.5:
$ sudo pacman -S gcc-libs

N.B. EXTRA_CFLAGS name wasn't used, because it's also used by libbpf's
Makefile and this causes few issues:
1. default "-g -Wall" flags are overriden;
2. compiling shared library with AddressSanitizer generates a bunch of symbols
like: "_GLOBAL__sub_D_00099_0_btf_dump.c", "_GLOBAL__sub_D_00099_0_bpf.c",
etc, which screws up versioned symbols check.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Cc: Julia Kartseva <hex@fb.com>
Link: https://lore.kernel.org/bpf/20200429012111.277390-3-andriin@fb.com

selftests/bpf: Ensure test flavors use correct skeletons

Ensure that test runner flavors include their own skeletons from <flavor>/
directory. Previously, skeletons generated for no-flavor test_progs were used.
Apart from fixing correctness, this also makes it possible to compile only
flavors individually:

$ make clean && make test_progs-no_alu32
... now succeeds ...

Fixes: 74b5a5968fe8 ("selftests/bpf: Replace test_progs and test_maps w/ general rule")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200429012111.277390-2-andriin@fb.com

selftests/bpf: Copy runqslower to OUTPUT directory

$(OUTPUT)/runqslower makefile target doesn't actually create runqslower
binary in the $(OUTPUT) directory. As lib.mk expects all
TEST_GEN_PROGS_EXTENDED (which runqslower is a part of) to be present in
the OUTPUT directory, this results in an error when running e.g. `make
install`:

rsync: link_stat "tools/testing/selftests/bpf/runqslower" failed: No
such file or directory (2)

Copy the binary into the OUTPUT directory after building it to fix the
error.

Fixes: 3a0d3092a4ed ("selftests/bpf: Build runqslower from selftests")
Signed-off-by: Veronika Kabatova <vkabatov@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200428173742.2988395-1-vkabatov@redhat.com

selftests/bpf: Add vmlinux.h selftest exercising tracing of syscalls

Add vmlinux.h generation to selftest/bpf's Makefile. Use it from newly added
test_vmlinux to trace nanosleep syscall using 5 different types of programs:
- tracepoint;
- raw tracepoint;
- raw tracepoint w/ direct memory reads (tp_btf);
- kprobe;
- fentry.

These programs are realistic variants of real-life tracing programs,
excercising vmlinux.h's usage with tracing applications.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200313172336.1879637-5-andriin@fb.com

tools/bpf: Move linux/types.h for selftests and bpftool

Commit fe4eb069edb7 ("bpftool: Use linux/types.h from source tree for
profiler build") added a build dependency on tools/testing/selftests/bpf
to tools/bpf/bpftool. This is suboptimal with respect to a possible
stand-alone build of bpftool.

Fix this by moving tools/testing/selftests/bpf/include/uapi/linux/types.h
to tools/include/uapi/linux/types.h.

This requires an adjustment in the include search path order for the
tests in tools/testing/selftests/bpf so that tools/include/linux/types.h
is selected when building host binaries and
tools/include/uapi/linux/types.h is selected when building bpf binaries.

Verified by compiling bpftool and the bpf selftests on x86_64 with this
change.

Fixes: fe4eb069edb7 ("bpftool: Use linux/types.h from source tree for profiler build")
Suggested-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20200313113105.6918-1-tklauser@distanz.ch

tools/testing/selftests/bpf: Add self-tests for new helper bpf_get_ns_current_pid_tgid.

Self tests added for new helper bpf_get_ns_current_pid_tgid

Signed-off-by: Carlos Neira <cneirabustos@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200304204157.58695-4-cneirabustos@gmail.com

selftests/bpf: Support out-of-tree vmlinux builds for VMLINUX_BTF

Add detection of out-of-tree built vmlinux image for the purpose of
VMLINUX_BTF detection. According to Documentation/kbuild/kbuild.rst, O takes
precedence over KBUILD_OUTPUT.

Also ensure ~/path/to/build/dir also works by relying on wildcard's resolution
first, but then applying $(abspath) at the end to also handle
O=../../whatever cases.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200304184336.165766-1-andriin@fb.com

selftests/bpf: Add test for "bpftool feature" command

Add Python module with tests for "bpftool feature" command, which mainly
checks whether the "full" option is working properly.

Signed-off-by: Michal Rostecki <mrostecki@opensuse.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20200226165941.6379-6-mrostecki@opensuse.org

selftests/bpf: Print backtrace on SIGSEGV in test_progs

Due to various bugs in tests clean up code (usually), if host system is
misconfigured, it happens that test_progs will just crash in the middle of
running a test with little to no indication of where and why the crash
happened. For cases where coredump is not readily available (e.g., inside
a CI), it's very helpful to have a stack trace, which lead to crash, to be
printed out. This change adds a signal handler that will capture and print out
symbolized backtrace:

$ sudo ./test_progs -t mmap
test_mmap:PASS:skel_open_and_load 0 nsec
test_mmap:PASS:bss_mmap 0 nsec
test_mmap:PASS:data_mmap 0 nsec
Caught signal #11!
Stack trace:
./test_progs(crash_handler+0x18)[0x42a888]
/lib64/libpthread.so.0(+0xf5d0)[0x7f2aab5175d0]
./test_progs(test_mmap+0x3c0)[0x41f0a0]
./test_progs(main+0x160)[0x407d10]
/lib64/libc.so.6(__libc_start_main+0xf5)[0x7f2aab15d3d5]
./test_progs[0x407ebc]
[1] 1988412 segmentation fault (core dumped) sudo ./test_progs -t mmap

Unfortunately, glibc's symbolization support is unable to symbolize static
functions, only global ones will be present in stack trace. But it's still a
step forward without adding extra libraries to get a better symbolization.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200225000847.3965188-1-andriin@fb.com

selftests/bpf: Change llvm flag -mcpu=probe to -mcpu=v3

The latest llvm supports cpu version v3, which is cpu version v1
plus some additional 64bit jmp insns and 32bit jmp insn support.

In selftests/bpf Makefile, the llvm flag -mcpu=probe did runtime
probe into the host system. Depending on compilation environments,
it is possible that runtime probe may fail, e.g., due to
memlock issue. This will cause generated code with cpu version v1.
This may cause confusion as the same compiler and the same C code
generates different byte codes in different environment.

Let us change the llvm flag -mcpu=probe to -mcpu=v3 so the
generated code will be the same regardless of the compilation
environment.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200219004236.2291125-1-yhs@fb.com

selftests/bpf: Improve bpftool changes detection

Detect when bpftool source code changes and trigger rebuild within
selftests/bpf Makefile. Also fix few small formatting problems.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20200124054148.2455060-1-andriin@fb.com

selftests/bpf: Build urandom_read with LDFLAGS and LDLIBS

During cross-compilation, it was discovered that LDFLAGS and
LDLIBS were not being used while building binaries, leading
to defaults which were not necessarily correct.

OpenEmbedded reported this kind of problem:

ERROR: QA Issue: No GNU_HASH in the ELF binary [...], didn't pass LDFLAGS?

Signed-off-by: Daniel Díaz <daniel.diaz@linaro.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>

selftests: Refactor build to remove tools/lib/bpf from include path

To make sure no new files are introduced that doesn't include the bpf/
prefix in its #include, remove tools/lib/bpf from the include path
entirely.

Instead, we introduce a new header files directory under the scratch tools/
dir, and add a rule to run the 'install_headers' rule from libbpf to have a
full set of consistent libbpf headers in $(OUTPUT)/tools/include/bpf, and
then use $(OUTPUT)/tools/include as the include path for selftests.

For consistency we also make sure we put all the scratch build files from
other bpftool and libbpf into tools/build/, so everything stays within
selftests/.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/157952561246.1683545.2762245552022369203.stgit@toke.dk

selftests: Use consistent include paths for libbpf

Fix all selftests to include libbpf header files with the bpf/ prefix, to
be consistent with external users of the library. Also ensure that all
includes of exported libbpf header files (those that are exported on 'make
install' of the library) use bracketed includes instead of quoted.

To not break the build, keep the old include path until everything has been
changed to the new one; a subsequent patch will remove that.

Fixes: 6910d7d3867a ("selftests/bpf: Ensure bpf_helper_defs.h are taken from selftests dir")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/157952560568.1683545.9649335788846513446.stgit@toke.dk

selftests: Pass VMLINUX_BTF to runqslower Makefile

Add a VMLINUX_BTF variable with the locally-built path when calling the
runqslower Makefile from selftests. This makes sure a simple 'make'
invocation in the selftests dir works even when there is no BTF information
for the running kernel. Do a wildcard expansion and include the same paths
for BTF for the running kernel as in the runqslower Makefile, to make it
possible to build selftests without having a vmlinux in the local tree.

Also fix the make invocation to use $(OUTPUT)/tools as the destination
directory instead of $(CURDIR)/tools.

Fixes: 3a0d3092a4ed ("selftests/bpf: Build runqslower from selftests")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/157952560344.1683545.2723631988771664417.stgit@toke.dk

selftests/bpf: Build runqslower from selftests

Ensure runqslower tool is built as part of selftests to prevent it from bit
rotting.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200113073143.1779940-7-andriin@fb.com

selftests/bpf: Conform selftests/bpf Makefile output to libbpf and bpftool

Bring selftest/bpf's Makefile output to the same format used by libbpf and
bpftool: 2 spaces of padding on the left + 8-character left-aligned build step
identifier.

Also, hide feature detection output by default. Can be enabled back by setting
V=1.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200113073143.1779940-4-andriin@fb.com

selftests/bpf: Further clean up Makefile output

Further clean up Makefile output:
- hide "entering directory" messages;
- silvence sub-Make command echoing;
- succinct MKDIR messages.

Also remove few test binaries that are not produced anymore from .gitignore.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200110051716.1591485-4-andriin@fb.com

selftests/bpf: Ensure bpf_helper_defs.h are taken from selftests dir

Reorder includes search path to ensure $(OUTPUT) and $(CURDIR) go before
libbpf's directory. Also fix bpf_helpers.h to include bpf_helper_defs.h in
such a way as to leverage includes search path. This allows selftests to not
use libbpf's local and potentially stale bpf_helper_defs.h. It's important
because selftests/bpf's Makefile only re-generates bpf_helper_defs.h in
seltests' output directory, not the one in libbpf's directory.

Also force regeneration of bpf_helper_defs.h when libbpf.a is updated to
reduce staleness.

Fixes: fa633a0f8919 ("libbpf: Fix build on read-only filesystems")
Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200110051716.1591485-3-andriin@fb.com

libbpf,selftests/bpf: Fix clean targets

Libbpf's clean target should clean out generated files in $(OUTPUT) directory
and not make assumption that $(OUTPUT) directory is current working directory.

Selftest's Makefile should delegate cleaning of libbpf-generated files to
libbpf's Makefile. This ensures more robust clean up.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200110051716.1591485-2-andriin@fb.com

bpftool: Make skeleton C code compilable with C++ compiler

When auto-generated BPF skeleton C code is included from C++ application, it
triggers compilation error due to void * being implicitly casted to whatever
target pointer type. This is supported by C, but not C++. To solve this
problem, add explicit casts, where necessary.

To ensure issues like this are captured going forward, add skeleton usage in
test_cpp test.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191226210253.3132060-1-andriin@fb.com

libbpf: Fix build on read-only filesystems

I got the following error when I tried to build perf on a read-only
filesystem with O=dir option.

$ cd /some/where/ro/linux/tools/perf
$ make O=$HOME/build/perf
...
CC /home/namhyung/build/perf/lib.o
/bin/sh: bpf_helper_defs.h: Read-only file system
make[3]: *** [Makefile:184: bpf_helper_defs.h] Error 1
make[2]: *** [Makefile.perf:778: /home/namhyung/build/perf/libbpf.a] Error 2
make[2]: *** Waiting for unfinished jobs....
LD /home/namhyung/build/perf/libperf-in.o
AR /home/namhyung/build/perf/libperf.a
PERF_VERSION = 5.4.0
make[1]: *** [Makefile.perf:225: sub-make] Error 2
make: *** [Makefile:70: all] Error 2

It was becaused bpf_helper_defs.h was generated in current directory.
Move it to OUTPUT directory.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20191223061326.843366-1-namhyung@kernel.org

selftests/bpf: Convert test_cgroup_attach to prog_tests

Convert test_cgroup_attach to prog_tests.

This change does a lot of things but in many cases it's pretty expensive
to separate them, so they go in one commit. Nevertheless the logic is
ketp as is and changes made are just moving things around, simplifying
them (w/o changing the meaning of the tests) and making prog_tests
compatible:

* split the 3 tests in the file into 3 separate files in prog_tests/;

* rename the test functions to test_<file_base_name>;

* remove unused includes, constants, variables and functions from every
test;

* replace `if`-s with or `if (CHECK())` where additional context should
be logged and with `if (CHECK_FAIL())` where line number is enough;

* switch from `log_err()` to logging via `CHECK()`;

* replace `assert`-s with `CHECK_FAIL()` to avoid crashing the whole
test_progs if one assertion fails;

* replace cgroup_helpers with test__join_cgroup() in
cgroup_attach_override only, other tests need more fine-grained
control for cgroup creation/deletion so cgroup_helpers are still used
there;

* simplify cgroup_attach_autodetach by switching to easiest possible
program since this test doesn't really need such a complicated program
as cgroup_attach_multi does;

* remove test_cgroup_attach.c itself.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/0ff19cc64d2dc5cf404349f07131119480e10e32.1576741281.git.rdna@fb.com

selftests/bpf: More succinct Makefile output

Similarly to bpftool/libbpf output, make selftests/bpf output succinct
per-item output line. Output is roughly as follows:

$ make
...
CLANG-LLC [test_maps] pyperf600.o
CLANG-LLC [test_maps] strobemeta.o
CLANG-LLC [test_maps] pyperf100.o
EXTRA-OBJ [test_progs] cgroup_helpers.o
EXTRA-OBJ [test_progs] trace_helpers.o
BINARY test_align
BINARY test_verifier_log
GEN-SKEL [test_progs] fexit_bpf2bpf.skel.h
GEN-SKEL [test_progs] test_global_data.skel.h
GEN-SKEL [test_progs] sendmsg6_prog.skel.h
...

To see the actual command invocation, verbose mode can be turned on with V=1
argument:

$ make V=1

... very verbose output ...

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20191217061425.2346359-1-andriin@fb.com

libbpf: Support libbpf-provided extern variables

Add support for extern variables, provided to BPF program by libbpf. Currently
the following extern variables are supported:
- LINUX_KERNEL_VERSION; version of a kernel in which BPF program is
executing, follows KERNEL_VERSION() macro convention, can be 4- and 8-byte
long;
- CONFIG_xxx values; a set of values of actual kernel config. Tristate,
boolean, strings, and integer values are supported.

Set of possible values is determined by declared type of extern variable.
Supported types of variables are:
- Tristate values. Are represented as `enum libbpf_tristate`. Accepted values
are **strictly** 'y', 'n', or 'm', which are represented as TRI_YES, TRI_NO,
or TRI_MODULE, respectively.
- Boolean values. Are represented as bool (_Bool) types. Accepted values are
'y' and 'n' only, turning into true/false values, respectively.
- Single-character values. Can be used both as a substritute for
bool/tristate, or as a small-range integer:
- 'y'/'n'/'m' are represented as is, as characters 'y', 'n', or 'm';
- integers in a range [-128, 127] or [0, 255] (depending on signedness of
char in target architecture) are recognized and represented with
respective values of char type.
- Strings. String values are declared as fixed-length char arrays. String of
up to that length will be accepted and put in first N bytes of char array,
with the rest of bytes zeroed out. If config string value is longer than
space alloted, it will be truncated and warning message emitted. Char array
is always zero terminated. String literals in config have to be enclosed in
double quotes, just like C-style string literals.
- Integers. 8-, 16-, 32-, and 64-bit integers are supported, both signed and
unsigned variants. Libbpf enforces parsed config value to be in the
supported range of corresponding integer type. Integers values in config can
be:
- decimal integers, with optional + and - signs;
- hexadecimal integers, prefixed with 0x or 0X;
- octal integers, starting with 0.

Config file itself is searched in /boot/config-$(uname -r) location with
fallback to /proc/config.gz, unless config path is specified explicitly
through bpf_object_open_opts' kernel_config_path option. Both gzipped and
plain text formats are supported. Libbpf adds explicit dependency on zlib
because of this, but this shouldn't be a problem, given libelf already depends
on zlib.

All detected extern variables, are put into a separate .extern internal map.
It, similarly to .rodata map, is marked as read-only from BPF program side, as
well as is frozen on load. This allows BPF verifier to track extern values as
constants and perform enhanced branch prediction and dead code elimination.
This can be relied upon for doing kernel version/feature detection and using
potentially unsupported field relocations or BPF helpers in a CO-RE-based BPF
program, while still having a single version of BPF program running on old and
new kernels. Selftests are validating this explicitly for unexisting BPF
helper.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191214014710.3449601-3-andriin@fb.com

selftests/bpf: Add BPF skeletons selftests and convert attach_probe.c

Add BPF skeleton generation to selftest/bpf's Makefile. Convert attach_probe.c
to use skeleton.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20191214014341.3442258-15-andriin@fb.com

selftests/bpf: Move reuseport tests under prog_tests/

Do a pure move the show the actual work needed to adapt the tests in
subsequent patch at the cost of breaking test_progs build for the moment.

Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191212102259.418536-10-jakub@cloudflare.com

selftests/bpf: Bring back c++ include/link test

Commit 5c26f9a78358 ("libbpf: Don't use cxx to test_libpf target")
converted existing c++ test to c. We still want to include and
link against libbpf from c++ code, so reinstate this test back,
this time in a form of a selftest with a clear comment about
its purpose.

v2:
* -lelf -> $(LDLIBS) (Andrii Nakryiko)

Fixes: 5c26f9a78358 ("libbpf: Don't use cxx to test_libpf target")
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20191202215931.248178-1-sdf@google.com

selftests/bpf: Ensure no DWARF relocations for BPF object files

Add -mattr=dwarfris attribute to llc to avoid having relocations against DWARF
data. These relocations make it impossible to inspect DWARF contents: all
strings are invalid.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191121070743.1309473-2-andriin@fb.com

selftests/bpf: Enforce no-ALU32 for test_progs-no_alu32

With the most recent Clang, alu32 is enabled by default if -mcpu=probe or
-mcpu=v3 is specified. Use a separate build rule with -mcpu=v2 to enforce no
ALU32 mode.

Suggested-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20191120002510.4130605-1-andriin@fb.com