diff options
| author | Maxim Mikityanskiy <maximmi@nvidia.com> | 2021-11-30 20:18:11 +0200 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2021-12-03 23:49:14 +0100 |
| commit | da54ab14953c38d98cb3e34c564c06c3739394b2 (patch) | |
| tree | 20e882b96ade95ea3ab1d80f7a1a8af545e8b758 /tools/testing/selftests/bpf/prog_tests/bpf_iter.c | |
| parent | 78c1f8d0634cc35da613d844eda7c849fc50f643 (diff) | |
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
Diffstat (limited to 'tools/testing/selftests/bpf/prog_tests/bpf_iter.c')
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/bpf_iter.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c index 0b996be923b5..b84f859b1267 100644 --- a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c +++ b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c @@ -1206,13 +1206,14 @@ static void test_task_vma(void) goto out; /* Read CMP_BUFFER_SIZE (1kB) from bpf_iter. Read in small chunks - * to trigger seq_file corner cases. The expected output is much - * longer than 1kB, so the while loop will terminate. + * to trigger seq_file corner cases. */ len = 0; while (len < CMP_BUFFER_SIZE) { err = read_fd_into_buffer(iter_fd, task_vma_output + len, min(read_size, CMP_BUFFER_SIZE - len)); + if (!err) + break; if (CHECK(err < 0, "read_iter_fd", "read_iter_fd failed\n")) goto out; len += err; |