diff options
| author | Mykyta Yatsenko <yatsenko@meta.com> | 2025-10-29 22:59:07 +0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2025-10-30 04:15:30 +0300 |
| commit | 5913e936f6d5d348e33190885131c4f4eaa4bc4b (patch) | |
| tree | 6940fd63ef2277743c00b787e2842b09c3d6d466 /tools | |
| parent | e2e668bd81066086fc5a676c8dcb8121a7d84d98 (diff) | |
| download | linux-5913e936f6d5d348e33190885131c4f4eaa4bc4b.tar.xz | |
selftests/bpf: Fix intermittent failures in file_reader test
file_reader/on_open_expect_fault intermittently fails when test_progs
runs tests in parallel, because it expects a page fault on first read.
Another file_reader test running concurrently may have already pulled
the same pages into the page cache, eliminating the fault and causing a
spurious failure.
Make file_reader/on_open_expect_fault read from a file region that does
not overlap with other file_reader tests, so the initial access still
faults even under parallel execution.
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Acked-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Link: https://lore.kernel.org/r/20251029195907.858217-1-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/file_reader.c | 6 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/progs/file_reader.c | 2 |
2 files changed, 6 insertions, 2 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/file_reader.c b/tools/testing/selftests/bpf/prog_tests/file_reader.c index 2a034d43b73e..5cde32b35da4 100644 --- a/tools/testing/selftests/bpf/prog_tests/file_reader.c +++ b/tools/testing/selftests/bpf/prog_tests/file_reader.c @@ -52,7 +52,11 @@ static int initialize_file_contents(void) /* page-align base file address */ addr = (void *)((unsigned long)addr & ~(page_sz - 1)); - for (off = 0; off < sizeof(file_contents); off += page_sz) { + /* + * Page out range 0..512K, use 0..256K for positive tests and + * 256K..512K for negative tests expecting page faults + */ + for (off = 0; off < sizeof(file_contents) * 2; off += page_sz) { if (!ASSERT_OK(madvise(addr + off, page_sz, MADV_PAGEOUT), "madvise pageout")) return errno; diff --git a/tools/testing/selftests/bpf/progs/file_reader.c b/tools/testing/selftests/bpf/progs/file_reader.c index 2585f83b0ce5..166c3ac6957d 100644 --- a/tools/testing/selftests/bpf/progs/file_reader.c +++ b/tools/testing/selftests/bpf/progs/file_reader.c @@ -49,7 +49,7 @@ int on_open_expect_fault(void *c) if (bpf_dynptr_from_file(file, 0, &dynptr)) goto out; - local_err = bpf_dynptr_read(tmp_buf, user_buf_sz, &dynptr, 0, 0); + local_err = bpf_dynptr_read(tmp_buf, user_buf_sz, &dynptr, user_buf_sz, 0); if (local_err == -EFAULT) { /* Expect page fault */ local_err = 0; run_success = 1; |