selftests/bpf: Add assert for user stacks in test_task_stack

This is a follow up to:
commit b8e3a87a627b ("bpf: Add crosstask check to __bpf_get_stack").

This test ensures that the task iterator only gets a single
user stack (for the current task).

Signed-off-by: Jordan Rome <linux@jordanrome.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20231112023010.144675-1-linux@jordanrome.com

selftests/bpf: Add malloc failure checks in bpf_iter

Since some malloc calls in bpf_iter may at times fail,
this patch adds the appropriate fail checks, and ensures that
any previously allocated resource is appropriately destroyed
before returning the function.

Signed-off-by: Yuran Pereira <yuran.pereira@hotmail.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Acked-by: Kui-Feng Lee <thinker.li@gmail.com>
Link: https://lore.kernel.org/r/DB3PR10MB6835F0ECA792265FA41FC39BE8A3A@DB3PR10MB6835.EURPRD10.PROD.OUTLOOK.COM
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Convert CHECK macros to ASSERT_* macros in bpf_iter

As it was pointed out by Yonghong Song [1], in the bpf selftests the use
of the ASSERT_* series of macros is preferred over the CHECK macro.
This patch replaces all CHECK calls in bpf_iter with the appropriate
ASSERT_* macros.

[1] https://lore.kernel.org/lkml/0a142924-633c-44e6-9a92-2dc019656bf2@linux.dev

Suggested-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Yuran Pereira <yuran.pereira@hotmail.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Acked-by: Kui-Feng Lee <thinker.li@gmail.com>
Link: https://lore.kernel.org/r/DB3PR10MB6835E9C8DFCA226DD6FEF914E8A3A@DB3PR10MB6835.EURPRD10.PROD.OUTLOOK.COM
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: rename bpf_iter_task.c to bpf_iter_tasks.c

The newly-added struct bpf_iter_task has a name collision with a selftest
for the seq_file task iter's bpf skel, so the selftests/bpf/progs file is
renamed in order to avoid the collision.

Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231018061746.111364-8-zhouchuyi@bytedance.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Rename bpf_iter_task_vma.c to bpf_iter_task_vmas.c

Further patches in this series will add a struct bpf_iter_task_vma,
which will result in a name collision with the selftest prog renamed in
this patch. Rename the selftest to avoid the collision.

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20231013204426.1074286-3-davemarchevsky@fb.com

selftests/bpf: Use bpf_{btf,link,map,prog}_get_info_by_fd()

Use the new type-safe wrappers around bpf_obj_get_info_by_fd().
Fix a prog/map mixup in prog_holds_map().

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230214231221.249277-6-iii@linux.ibm.com

selftests/bpf: add a test for iter/task_vma for short-lived processes

When a task iterator traverses vma(s), it is possible task->mm might
become invalid in the middle of traversal and this may cause kernel
misbehave (e.g., crash)

This test case creates iterators repeatedly and forks short-lived
processes in the background to detect this bug. The test will last
for 3 seconds to get the chance to trigger the issue.

Signed-off-by: Kui-Feng Lee <kuifeng@meta.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20221216221855.4122288-3-kuifeng@meta.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Add write to hashmap to array_map iter test

Modify iter prog in existing bpf_iter_bpf_array_map.c, which currently
dumps arraymap key/val, to also do a write of (val, key) into a
newly-added hashmap. Confirm that the write succeeds as expected by
modifying the userspace runner program.

Before a change added in an earlier commit - considering PTR_TO_BUF reg
a valid input to helpers which expect MAP_{KEY,VAL} - the verifier
would've rejected this prog change due to type mismatch. Since using
current iter's key/val to access a separate map is a reasonable usecase,
let's add support for it.

Note that the test prog cannot directly write (val, key) into hashmap
via bpf_map_update_elem when both come from iter context because key is
marked MEM_RDONLY. This is due to bpf_map_update_elem - and other basic
map helpers - taking ARG_PTR_TO_MAP_{KEY,VALUE} w/o MEM_RDONLY type
flag. bpf_map_{lookup,update,delete}_elem don't modify their
input key/val so it should be possible to tag their args READONLY, but
due to the ubiquitous use of these helpers and verifier checks for
type == MAP_VALUE, such a change is nontrivial and seems better to
address in a followup series.

Also fixup some 'goto's in test runner's map checking loop.

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221020160721.4030492-4-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Use sys_pidfd_open() helper when possible

SYS_pidfd_open may be undefined for old glibc, so using sys_pidfd_open()
helper defined in task_local_storage_helpers.h instead to fix potential
build failure.

And according to commit 7615d9e1780e ("arch: wire-up pidfd_open()"), the
syscall number of pidfd_open is always 434 except for alpha architure,
so update the definition of __NR_pidfd_open accordingly.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221011071249.3471760-1-houtao@huaweicloud.com

selftests/bpf: Add missing bpf_iter_vma_offset__destroy call

Adding missing bpf_iter_vma_offset__destroy call and using in-skeletin
link pointer so we don't need extra bpf_link__destroy call.

Fixes: b3e1331eb925 ("selftests/bpf: Test parameterized task BPF iterators.")
Cc: Kui-Feng Lee <kuifeng@fb.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20221006083106.117987-1-jolsa@kernel.org
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

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: Ensure sleepable program is rejected by hash map iter

Add a test to ensure sleepable program is rejected by hash map iterator.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20220810080538.1845898-10-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Add write tests for sk local storage map iterator

Add test to validate the overwrite of sock local storage map value in
map iterator and another one to ensure out-of-bound value writing is
rejected.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220810080538.1845898-9-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Add tests for reading a dangling map iter fd

After closing both related link fd and map fd, reading the map
iterator fd to ensure it is OK to do so.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20220810080538.1845898-8-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: add a ksym iter subtest

add subtest verifying BPF ksym iter behaviour. The BPF ksym
iter program shows an example of dumping a format different to
/proc/kallsyms. It adds KIND and MAX_SIZE fields which represent the
kind of symbol (core kernel, module, ftrace, bpf, or kprobe) and
the maximum size the symbol can be. The latter is calculated from
the difference between current symbol value and the next symbol
value.

The key benefit for this iterator will likely be supporting in-kernel
data-gathering rather than dumping symbol details to userspace and
parsing the results.

Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/1657629105-7812-3-git-send-email-alan.maguire@oracle.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Add bpf link iter test

Add a simple test for bpf link iterator

Signed-off-by: Dmitrii Dolgov <9erthalion6@gmail.com>
Link: https://lore.kernel.org/r/20220510155233.9815-5-9erthalion6@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Use ASSERT_* instead of CHECK

Replace usage of CHECK with a corresponding ASSERT_* macro for bpf_iter
tests. Only done if the final result is equivalent, no changes when
replacement means loosing some information, e.g. from formatting string.

Signed-off-by: Dmitrii Dolgov <9erthalion6@gmail.com>
Link: https://lore.kernel.org/r/20220510155233.9815-4-9erthalion6@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Fix result check for test_bpf_hash_map

The original condition looks like a typo, verify the skeleton loading
result instead.

Signed-off-by: Dmitrii Dolgov <9erthalion6@gmail.com>
Link: https://lore.kernel.org/r/20220510155233.9815-3-9erthalion6@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Drop duplicate max/min definitions

Drop duplicate macros min() and MAX() definitions in prog_tests and use
MIN() or MAX() in sys/param.h instead.

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/1ae276da9925c2de59b5bdc93b693b4c243e692e.1649462033.git.geliang.tang@suse.com

selftests/bpf: Add test for sleepable bpf iterator programs

This adds a test for bpf iterator programs to make use of sleepable
bpf helpers.

Signed-off-by: Kenny Yu <kennyyu@fb.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220124185403.468466-5-kennyyu@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

bpf: Fix the test_task_vma selftest to support output shorter than 1 kB

The test for bpf_iter_task_vma assumes that the output will be longer
than 1 kB, as the comment above the loop says. Due to this assumption,
the loop becomes infinite if the output turns to be shorter than 1 kB.
The return value of read_fd_into_buffer is 0 when the end of file was
reached, and len isn't being increased any more.

This commit adds a break on EOF to handle short output correctly. For
the reference, this is the contents that I get when running test_progs
under vmtest.sh, and it's shorter than 1 kB:

00400000-00401000 r--p 00000000 fe:00 25867 /root/bpf/test_progs
00401000-00674000 r-xp 00001000 fe:00 25867 /root/bpf/test_progs
00674000-0095f000 r--p 00274000 fe:00 25867 /root/bpf/test_progs
0095f000-00983000 r--p 0055e000 fe:00 25867 /root/bpf/test_progs
00983000-00a8a000 rw-p 00582000 fe:00 25867 /root/bpf/test_progs
00a8a000-0484e000 rw-p 00000000 00:00 0
7f6c64000000-7f6c64021000 rw-p 00000000 00:00 0
7f6c64021000-7f6c68000000 ---p 00000000 00:00 0
7f6c6ac8f000-7f6c6ac90000 r--s 00000000 00:0d 8032
anon_inode:bpf-map
7f6c6ac90000-7f6c6ac91000 ---p 00000000 00:00 0
7f6c6ac91000-7f6c6b491000 rw-p 00000000 00:00 0
7f6c6b491000-7f6c6b492000 r--s 00000000 00:0d 8032
anon_inode:bpf-map
7f6c6b492000-7f6c6b493000 rw-s 00000000 00:0d 8032
anon_inode:bpf-map
7ffc1e23d000-7ffc1e25e000 rw-p 00000000 00:00 0
7ffc1e3b8000-7ffc1e3bc000 r--p 00000000 00:00 0
7ffc1e3bc000-7ffc1e3bd000 r-xp 00000000 00:00 0
7fffffffe000-7ffffffff000 --xp 00000000 00:00 0

Fixes: e8168840e16c ("selftests/bpf: Add test for bpf_iter_task_vma")
Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211130181811.594220-1-maximmi@nvidia.com

selftests/bpf: Migrate selftests to bpf_map_create()

Conversion is straightforward for most cases. In few cases tests are
using mutable map_flags and attribute structs, but bpf_map_create_opts
can be used in the similar fashion, so there were no problems. Just lots
of repetitive conversions.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211124193233.3115996-5-andrii@kernel.org

selftests/bpf: Free per-cpu values array in bpf_iter selftest

Array holding per-cpu values wasn't freed. Fix that.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211107165521.9240-5-andrii@kernel.org

selftests/bpf: Fix a few compiler warnings

With clang building selftests/bpf, I hit a few warnings like below:

.../bpf_iter.c:592:48: warning: variable 'expected_key_c' set but not used [-Wunused-but-set-variable]
__u32 expected_key_a = 0, expected_key_b = 0, expected_key_c = 0;
^

.../bpf_iter.c:688:48: warning: variable 'expected_key_c' set but not used [-Wunused-but-set-variable]
__u32 expected_key_a = 0, expected_key_b = 0, expected_key_c = 0;
^

.../tc_redirect.c:657:6: warning: variable 'target_fd' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
if (!ASSERT_OK_PTR(nstoken, "setns " NS_FWD))
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.../tc_redirect.c:743:6: note: uninitialized use occurs here
if (target_fd >= 0)
^~~~~~~~~

Removing unused variables and initializing the previously-uninitialized variable
to ensure these warnings are gone.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210917043343.3711917-1-yhs@fb.com

selftest/bpf: Implement sample UNIX domain socket iterator program.

The iterator can output almost the same result compared to /proc/net/unix.
The header line is aligned, and the Inode column uses "%8lu" because "%5lu"
can be easily overflown.

# cat /sys/fs/bpf/unix
Num RefCount Protocol Flags Type St Inode Path
ffff963c06689800: 00000002 00000000 00010000 0001 01 18697 private/defer
ffff963c7c979c00: 00000002 00000000 00000000 0001 01 598245 @Hello@World@

# cat /proc/net/unix
Num RefCount Protocol Flags Type St Inode Path
ffff963c06689800: 00000002 00000000 00010000 0001 01 18697 private/defer
ffff963c7c979c00: 00000002 00000000 00000000 0001 01 598245 @Hello@World@

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210814015718.42704-4-kuniyu@amazon.co.jp

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

bpf/selftests: Add bpf_get_task_stack retval bounds test_prog

Add a libbpf test prog which feeds bpf_get_task_stack's return value
into seq_write after confirming it's positive. No attempt to bound the
value from above is made.

Load will fail if verifier does not refine retval range based on buf sz
input to bpf_get_task_stack.

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210416204704.2816874-4-davemarchevsky@fb.com

selftests/bpf: Add test for bpf_iter_task_vma

The test dumps information similar to /proc/pid/maps. The first line of
the output is compared against the /proc file to make sure they match.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210212183107.50963-4-songliubraving@fb.com

selftests/bpf: Test bpf_sk_storage_get in tcp iterators

This extends the existing bpf_sk_storage_get test where a socket is
created and tagged with its creator's pid by a task_file iterator.

A TCP iterator is now also used at the end of the test to negate the
values already stored in the local storage. The test therefore expects
-getpid() to be stored in the local storage.

Signed-off-by: Florent Revest <revest@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20201204113609.1850150-6-revest@google.com

selftests/bpf: Add an iterator selftest for bpf_sk_storage_get

The eBPF program iterates over all files and tasks. For all socket
files, it stores the tgid of the last task it encountered with a handle
to that socket. This is a heuristic for finding the "owner" of a socket
similar to what's done by lsof, ss, netstat or fuser. Potentially, this
information could be used from a cgroup_skb/*gress hook to try to
associate network traffic with processes.

The test makes sure that a socket it created is tagged with prog_tests's
pid.

Signed-off-by: Florent Revest <revest@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20201204113609.1850150-5-revest@google.com

selftests/bpf: Add an iterator selftest for bpf_sk_storage_delete

The eBPF program iterates over all entries (well, only one) of a socket
local storage map and deletes them all. The test makes sure that the
entry is indeed deleted.

Signed-off-by: Florent Revest <revest@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20201204113609.1850150-4-revest@google.com

selftests/bpf_iter: Don't fail test due to missing __builtin_btf_type_id

The new test for task iteration in bpf_iter checks (in do_btf_read()) if it
should be skipped due to missing __builtin_btf_type_id. However, this
'skip' verdict is not propagated to the caller, so the parent test will
still fail. Fix this by also skipping the rest of the parent test if the
skip condition was reached.

Fixes: b72091bd4ee4 ("selftests/bpf: Add test for bpf_seq_printf_btf helper")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/bpf/20200929123004.46694-1-toke@redhat.com

selftests/bpf: Add test for bpf_seq_printf_btf helper

Add a test verifying iterating over tasks and displaying BTF
representation of task_struct succeeds.

Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/1601292670-1616-9-git-send-email-alan.maguire@oracle.com

selftests/bpf: Fix overflow tests to reflect iter size increase

bpf iter size increase to PAGE_SIZE << 3 means overflow tests assuming
page size need to be bumped also.

Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/1601292670-1616-7-git-send-email-alan.maguire@oracle.com

selftests/bpf: Test task_file iterator without visiting pthreads

Modified existing bpf_iter_test_file.c program to check whether
all accessed files from the main thread or not.

Modified existing bpf_iter_test_file program to check
whether all accessed files from the main thread or not.
$ ./test_progs -n 4
...
#4/7 task_file:OK
...
#4 bpf_iter:OK
Summary: 1/24 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200902023113.1672863-1-yhs@fb.com

tools/bpf: Support new uapi for map element bpf iterator

Previous commit adjusted kernel uapi for map
element bpf iterator. This patch adjusted libbpf API
due to uapi change. bpftool and bpf_iter selftests
are also changed accordingly.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200805055058.1457623-1-yhs@fb.com

selftests/bpf: Test bpf_iter buffer access with negative offset

Commit afbf21dce668 ("bpf: Support readonly/readwrite buffers
in verifier") added readonly/readwrite buffer support which
is currently used by bpf_iter tracing programs. It has
a bug with incorrect parameter ordering which later fixed
by Commit f6dfbe31e8fa ("bpf: Fix swapped arguments in calls
to check_buffer_access").

This patch added a test case with a negative offset access
which will trigger the error path.

Without Commit f6dfbe31e8fa, running the test case in the patch,
the error message looks like:
R1_w=rdwr_buf(id=0,off=0,imm=0) R10=fp0
; value_sum += *(__u32 *)(value - 4);
2: (61) r1 = *(u32 *)(r1 -4)
R1 invalid (null) buffer access: off=-4, size=4

With the above commit, the error message looks like:
R1_w=rdwr_buf(id=0,off=0,imm=0) R10=fp0
; value_sum += *(__u32 *)(value - 4);
2: (61) r1 = *(u32 *)(r1 -4)
R1 invalid rdwr buffer access: off=-4, size=4

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200728221801.1090406-1-yhs@fb.com

selftests/bpf: Add a test for out of bound rdonly buf access

If the bpf program contains out of bound access w.r.t. a
particular map key/value size, the verification will be
still okay, e.g., it will be accepted by verifier. But
it will be rejected during link_create time. A test
is added here to ensure link_create failure did happen
if out of bound access happened.
$ ./test_progs -n 4
...
#4/23 rdonly-buf-out-of-bound:OK
...

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200723184124.591700-1-yhs@fb.com

selftests/bpf: Add a test for bpf sk_storage_map iterator

Added one test for bpf sk_storage_map_iterator.
$ ./test_progs -n 4
...
#4/22 bpf_sk_storage_map:OK
...

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200723184122.591591-1-yhs@fb.com

selftests/bpf: Add test for bpf array map iterators

Two subtests are added.
$ ./test_progs -n 4
...
#4/20 bpf_array_map:OK
#4/21 bpf_percpu_array_map:OK
...

The bpf_array_map subtest also tested bpf program
changing array element values and send key/value
to user space through bpf_seq_write() interface.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200723184121.591367-1-yhs@fb.com

selftests/bpf: Add test for bpf hash map iterators

Two subtests are added.
$ ./test_progs -n 4
...
#4/18 bpf_hash_map:OK
#4/19 bpf_percpu_hash_map:OK
...

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200723184120.590916-1-yhs@fb.com

selftests/bpf: Add bpf_iter test with bpf_get_task_stack()

The new test is similar to other bpf_iter tests. It dumps all
/proc/<pid>/stack to a seq_file. Here is some example output:

pid: 2873 num_entries: 3
[<0>] worker_thread+0xc6/0x380
[<0>] kthread+0x135/0x150
[<0>] ret_from_fork+0x22/0x30

pid: 2874 num_entries: 9
[<0>] __bpf_get_stack+0x15e/0x250
[<0>] bpf_prog_22a400774977bb30_dump_task_stack+0x4a/0xb3c
[<0>] bpf_iter_run_prog+0x81/0x170
[<0>] __task_seq_show+0x58/0x80
[<0>] bpf_seq_read+0x1c3/0x3b0
[<0>] vfs_read+0x9e/0x170
[<0>] ksys_read+0xa7/0xe0
[<0>] do_syscall_64+0x4c/0xa0
[<0>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

Note: bpf_iter test as-is doesn't print the contents of the seq_file. To
see the example above, it is necessary to add printf() to do_dummy_read.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200630062846.664389-5-songliubraving@fb.com

selftests/bpf: Add tcp/udp iterator programs to selftests

Added tcp{4,6} and udp{4,6} bpf programs into test_progs
selftest so that they at least can load successfully.
$ ./test_progs -n 3
...
#3/7 tcp4:OK
#3/8 tcp6:OK
#3/9 udp4:OK
#3/10 udp6:OK
...
#3 bpf_iter:OK
Summary: 1/16 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200623230823.3989372-1-yhs@fb.com

tools/bpf: selftests: Add bpf_iter selftests

The added test includes the following subtests:
- test verifier change for btf_id_or_null
- test load/create_iter/read for
ipv6_route/netlink/bpf_map/task/task_file
- test anon bpf iterator
- test anon bpf iterator reading one char at a time
- test file bpf iterator
- test overflow (single bpf program output not overflow)
- test overflow (single bpf program output overflows)
- test bpf prog returning 1

The ipv6_route tests the following verifier change
- access fields in the variable length array of the structure.

The netlink load tests the following verifier change
- put a btf_id ptr value in a stack and accessible to
tracing/iter programs.

The anon bpf iterator also tests link auto attach through skeleton.

$ test_progs -n 2
#2/1 btf_id_or_null:OK
#2/2 ipv6_route:OK
#2/3 netlink:OK
#2/4 bpf_map:OK
#2/5 task:OK
#2/6 task_file:OK
#2/7 anon:OK
#2/8 anon-read-one-char:OK
#2/9 file:OK
#2/10 overflow:OK
#2/11 overflow-e2big:OK
#2/12 prog-ret-1:OK
#2 bpf_iter:OK
Summary: 1/12 PASSED, 0 SKIPPED, 0 FAILED

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/20200509175923.2477637-1-yhs@fb.com