[PATCH] selftests/bpf: Fix flaky file_reader test

[Mykyta Yatsenko <mykyta.yatsenko5@gmail.com>]

From: Mykyta Yatsenko <yatsenko@meta.com>

file_reader/on_open_expect_fault test expects page fault
when reading pages from the test harness executable.
It is not guaranteed that those are paged out, even
after madvise(MADV_PAGEOUT).
Relax the condition in the test to succeed with both
0 and -EFAULT returned.

Fixes: 784cdf931543 ("selftests/bpf: add file dynptr tests")
Reported-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Closes: https://lore.kernel.org/all/ah6g7JSYOWGp2oAG@u94a/
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
---
 tools/testing/selftests/bpf/progs/file_reader.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/progs/file_reader.c b/tools/testing/selftests/bpf/progs/file_reader.c
index 462712ff3b8a..aa2c05cce2b3 100644
--- a/tools/testing/selftests/bpf/progs/file_reader.c
+++ b/tools/testing/selftests/bpf/progs/file_reader.c
@@ -50,7 +50,7 @@ int on_open_expect_fault(void *c)
 		goto out;
 
 	local_err = bpf_dynptr_read(tmp_buf, user_buf_sz, &dynptr, user_buf_sz, 0);
-	if (local_err == -EFAULT) { /* Expect page fault */
+	if (local_err == -EFAULT || local_err == 0) { /* Expect page fault or success */
 		local_err = 0;
 		run_success = 1;
 	}

---
base-commit: 245da8192c073820390f7fa1cc1e834b32119bce
change-id: 20260603-file_reader_flake-bf0753be6b2e

Best regards,
--  
Mykyta Yatsenko <yatsenko@meta.com>