selftests/bpf: Temporarily disable part of btf_dump:var_data test.

Commit 7443b296e699 ("x86/percpu: Move cpu_number next to current_task")
moved global per_cpu variable 'cpu_number' into pcpu_hot structure.
Therefore this part of var_data test is no longer valid.
Disable it until better solution is found.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Test skops->skb_hwtstamp

This patch tests reading the skops->skb_hwtstamp field.

A local test was also done such that the shinfo hwtstamp was temporary
set to a non zero value in the kernel bpf_skops_parse_hdr()
and the same value can be read by the skops test.

An adjustment is needed to the btf_dump selftest because
the changes in the 'struct bpf_sock_ops'.

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20221107230420.4192307-4-martin.lau@linux.dev

selftests/bpf: Test parameterized task BPF iterators.

Test iterators of vma, files and tasks.

Ensure the API works appropriately to visit all tasks,
tasks in a process, or a particular task.

Signed-off-by: Kui-Feng Lee <kuifeng@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/bpf/20220926184957.208194-5-kuifeng@fb.com

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

bpf: Add CGROUP prefix to cgroup_iter_order

bpf_cgroup_iter_order is globally visible but the entries do not have
CGROUP prefix. As requested by Andrii, put a CGROUP in the names
in bpf_cgroup_iter_order.

This patch fixes two previous commits: one introduced the API and
the other uses the API in bpf selftest (that is, the selftest
cgroup_hierarchical_stats).

I tested this patch via the following command:

test_progs -t cgroup,iter,btf_dump

Fixes: d4ccaf58a847 ("bpf: Introduce cgroup iter")
Fixes: 88886309d2e8 ("selftests/bpf: add a selftest for cgroup hierarchical stats collection")
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Hao Luo <haoluo@google.com>
Link: https://lore.kernel.org/r/20220825223936.1865810-1-haoluo@google.com
Signed-off-by: Martin KaFai Lau <kafai@fb.com>

selftests/bpf: Test cgroup_iter.

Add a selftest for cgroup_iter. The selftest creates a mini cgroup tree
of the following structure:

ROOT (working cgroup)
|
PARENT
/ \
CHILD1 CHILD2

and tests the following scenarios:

- invalid cgroup fd.
- pre-order walk over descendants from PARENT.
- post-order walk over descendants from PARENT.
- walk of ancestors from PARENT.
- process only a single object (i.e. PARENT).
- early termination.

Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Hao Luo <haoluo@google.com>
Link: https://lore.kernel.org/r/20220824233117.1312810-3-haoluo@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

bpf: Introduce cgroup iter

Cgroup_iter is a type of bpf_iter. It walks over cgroups in four modes:

- walking a cgroup's descendants in pre-order.
- walking a cgroup's descendants in post-order.
- walking a cgroup's ancestors.
- process only the given cgroup.

When attaching cgroup_iter, one can set a cgroup to the iter_link
created from attaching. This cgroup is passed as a file descriptor
or cgroup id and serves as the starting point of the walk. If no
cgroup is specified, the starting point will be the root cgroup v2.

For walking descendants, one can specify the order: either pre-order or
post-order. For walking ancestors, the walk starts at the specified
cgroup and ends at the root.

One can also terminate the walk early by returning 1 from the iter
program.

Note that because walking cgroup hierarchy holds cgroup_mutex, the iter
program is called with cgroup_mutex held.

Currently only one session is supported, which means, depending on the
volume of data bpf program intends to send to user space, the number
of cgroups that can be walked is limited. For example, given the current
buffer size is 8 * PAGE_SIZE, if the program sends 64B data for each
cgroup, assuming PAGE_SIZE is 4kb, the total number of cgroups that can
be walked is 512. This is a limitation of cgroup_iter. If the output
data is larger than the kernel buffer size, after all data in the
kernel buffer is consumed by user space, the subsequent read() syscall
will signal EOPNOTSUPP. In order to work around, the user may have to
update their program to reduce the volume of data sent to output. For
example, skip some uninteresting cgroups. In future, we may extend
bpf_iter flags to allow customizing buffer size.

Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Hao Luo <haoluo@google.com>
Link: https://lore.kernel.org/r/20220824233117.1312810-2-haoluo@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Update btf_dump case for conflicting names

Update btf_dump case for conflicting names caused by forward declaration.

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20220301053250.1464204-3-xukuohai@huawei.com

selftests/bpf: Fix UBSan complaint about signed __int128 overflow

Test is using __int128 variable as unsigned and highest order bit can be
set to 1 after bit shift. Use unsigned __int128 explicitly and prevent
UBSan from complaining.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211124002325.1737739-8-andrii@kernel.org

selftests/bpf: Fix trivial typo

Fix trivial typo in comment from 'oveflow' to 'overflow'.

Reported-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Drew Fustini <dfustini@baylibre.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211122070528.837806-1-dfustini@baylibre.com

selftests/bpf: Update btf_dump__new() uses to v1.0+ variant

Update to-be-deprecated forms of btf_dump__new().

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211111053624.190580-8-andrii@kernel.org

selftests/bpf: Clean up btf and btf_dump in dump_datasec test

Free up used resources at the end and on error. Also make it more
obvious that there is btf__parse() call that creates struct btf
instance.

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/20211107165521.9240-7-andrii@kernel.org

selftests/bpf: Normalize selftest entry points

Ensure that all test entry points are global void functions with no
input arguments. Mark few subtest entry points as static.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211022223228.99920-2-andrii@kernel.org

selftests/bpf: Switch to new btf__type_cnt/btf__raw_data APIs

Replace the calls to btf__get_nr_types/btf__get_raw_data in
selftests with new APIs btf__type_cnt/btf__raw_data. The old
APIs will be deprecated in libbpf v0.7+.

Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211022130623.1548429-6-hengqi.chen@gmail.com

selftests/bpf: Use cpu_number only on arches that have it

cpu_number exists only on Intel and aarch64, so skip the test involing
it on other arches. An alternative would be to replace it with an
exported non-ifdefed primitive-typed percpu variable from the common
code, but there appears to be none.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211013160902.428340-2-iii@linux.ibm.com

selftests/bpf: Fix btf_dump __int128 test failure with clang build kernel

With clang build kernel (adding LLVM=1 to kernel and selftests/bpf build
command line), I hit the following test failure:

$ ./test_progs -t btf_dump
...
btf_dump_data:PASS:ensure expected/actual match 0 nsec
btf_dump_data:FAIL:find type id unexpected find type id: actual -2 < expected 0
btf_dump_data:FAIL:find type id unexpected find type id: actual -2 < expected 0
test_btf_dump_int_data:FAIL:dump __int128 unexpected error: -2 (errno 2)
#15/9 btf_dump/btf_dump: int_data:FAIL

Further analysis showed gcc build kernel has type "__int128" in dwarf/BTF
and it doesn't exist in clang build kernel. Code searching for kernel code
found the following:
arch/s390/include/asm/types.h: unsigned __int128 pair;
crypto/ecc.c: unsigned __int128 m = (unsigned __int128)left * right;
include/linux/math64.h: return (u64)(((unsigned __int128)a * mul) >> shift);
include/linux/math64.h: return (u64)(((unsigned __int128)a * mul) >> shift);
lib/ubsan.h:typedef __int128 s_max;
lib/ubsan.h:typedef unsigned __int128 u_max;

In my case, CONFIG_UBSAN is not enabled. Even if we only have "unsigned __int128"
in the code, somehow gcc still put "__int128" in dwarf while clang didn't.
Hence current test works fine for gcc but not for clang.

Enabling CONFIG_UBSAN is an option to provide __int128 type into dwarf
reliably for both gcc and clang, but not everybody enables CONFIG_UBSAN
in their kernel build. So the best choice is to use "unsigned __int128" type
which is available in both clang and gcc build kernels. But clang and gcc
dwarf encoded names for "unsigned __int128" are different:

[$ ~] cat t.c
unsigned __int128 a;
[$ ~] gcc -g -c t.c && llvm-dwarfdump t.o | grep __int128
DW_AT_type (0x00000031 "__int128 unsigned")
DW_AT_name ("__int128 unsigned")
[$ ~] clang -g -c t.c && llvm-dwarfdump t.o | grep __int128
DW_AT_type (0x00000033 "unsigned __int128")
DW_AT_name ("unsigned __int128")

The test change in this patch tries to test type name before
doing actual test.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/bpf/20210924025856.2192476-1-yhs@fb.com

selftests/bpf: Add __int128-specific tests for typed data dump

Add tests for __int128 display for platforms that support it.
__int128s are dumped as hex values.

Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1626770993-11073-3-git-send-email-alan.maguire@oracle.com

selftests/bpf: Add dump type data tests to btf dump tests

Test various type data dumping operations by comparing expected
format with the dumped string; an snprintf-style printf function
is used to record the string dumped. Also verify overflow handling
where the data passed does not cover the full size of a type,
such as would occur if a tracer has a portion of the 8k
"struct task_struct".

Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1626362126-27775-4-git-send-email-alan.maguire@oracle.com

selftests/bpf: Turn on libbpf 1.0 mode and fix all IS_ERR checks

Turn ony libbpf 1.0 mode. Fix all the explicit IS_ERR checks that now will be
broken because libbpf returns NULL on error (and sets errno). Fix
ASSERT_OK_PTR and ASSERT_ERR_PTR to work for both old mode and new modes and
use them throughout selftests. This is trivial to do by using
libbpf_get_error() API that all libbpf users are supposed to use, instead of
IS_ERR checks.

A bunch of checks also did explicit -1 comparison for various fd-returning
APIs. Such checks are replaced with >= 0 or < 0 cases.

There were also few misuses of bpf_object__find_map_by_name() in test_maps.
Those are fixed in this patch as well.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20210525035935.1461796-3-andrii@kernel.org

selftests/bpf: Add remaining ASSERT_xxx() variants

Add ASSERT_TRUE/ASSERT_FALSE for conditions calculated with custom logic to
true/false. Also add remaining arithmetical assertions:
- ASSERT_LE -- less than or equal;
- ASSERT_GT -- greater than;
- ASSERT_GE -- greater than or equal.
This should cover most scenarios where people fall back to error-prone
CHECK()s.

Also extend ASSERT_ERR() to print out errno, in addition to direct error.

Also convert few CHECK() instances to ensure new ASSERT_xxx() variants work as
expected. Subsequent patch will also use ASSERT_TRUE/ASSERT_FALSE more
extensively.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Lorenz Bauer <lmb@cloudflare.com>
Link: https://lore.kernel.org/bpf/20210426192949.416837-2-andrii@kernel.org

selftests/bpf: Test "incremental" btf_dump in C format

Add test validating that btf_dump works fine with BTFs that are modified and
incrementally generated.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200929232843.1249318-5-andriin@fb.com

selftests/bpf: Fix btf_dump test cases on 32-bit arches

Fix btf_dump test cases by hard-coding BPF's pointer size of 8 bytes for cases
where it's impossible to deterimne the pointer size (no long type in BTF). In
cases where it's known, validate libbpf correctly determines it as 8.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200813204945.1020225-6-andriin@fb.com

selftests/bpf: Fix mix of tabs and spaces

Clang's -Wmisleading-indentation warns about misleading indentations if
there's a mixture of spaces and tabs. Remove extraneous spaces.

Signed-off-by: Bill Wendling <morbo@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200320201510.217169-1-morbo@google.com

selftests/bpf: Convert test_btf_dump into test_progs test

Convert test_btf_dump into a part of test_progs, instead of
a stand-alone test binary.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191008231009.2991130-3-andriin@fb.com