This is a note to let you know that I've just added the patch titled
selftests/bpf: Remove flaky test_btf_id test
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
selftests-bpf-remove-flaky-test_btf_id-test.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 56925f389e152dcb8d093435d43b78a310539c23 Mon Sep 17 00:00:00 2001
From: Yonghong Song <yonghong.song@xxxxxxxxx>
Date: Thu, 14 Dec 2023 12:38:20 -0800
Subject: selftests/bpf: Remove flaky test_btf_id test
From: Yonghong Song <yonghong.song@xxxxxxxxx>
commit 56925f389e152dcb8d093435d43b78a310539c23 upstream.
With previous patch, one of subtests in test_btf_id becomes
flaky and may fail. The following is a failing example:
Error: #26 btf
Error: #26/174 btf/BTF ID
Error: #26/174 btf/BTF ID
btf_raw_create:PASS:check 0 nsec
btf_raw_create:PASS:check 0 nsec
test_btf_id:PASS:check 0 nsec
...
test_btf_id:PASS:check 0 nsec
test_btf_id:FAIL:check BTF lingersdo_test_get_info:FAIL:check failed: -1
The test tries to prove a btf_id not available after the map is closed.
But btf_id is freed only after workqueue and a rcu grace period, compared
to previous case just after a rcu grade period.
Depending on system workload, workqueue could take quite some time
to execute function bpf_map_free_deferred() which may cause the test failure.
Instead of adding arbitrary delays, let us remove the logic to
check btf_id availability after map is closed.
Signed-off-by: Yonghong Song <yonghong.song@xxxxxxxxx>
Link: https://lore.kernel.org/r/20231214203820.1469402-1-yonghong.song@xxxxxxxxx
Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
Signed-off-by: Samasth Norway Ananda <samasth.norway.ananda@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
tools/testing/selftests/bpf/prog_tests/btf.c | 5 -----
1 file changed, 5 deletions(-)
--- a/tools/testing/selftests/bpf/prog_tests/btf.c
+++ b/tools/testing/selftests/bpf/prog_tests/btf.c
@@ -4630,11 +4630,6 @@ static int test_btf_id(unsigned int test
/* The map holds the last ref to BTF and its btf_id */
close(map_fd);
map_fd = -1;
- btf_fd[0] = bpf_btf_get_fd_by_id(map_info.btf_id);
- if (CHECK(btf_fd[0] >= 0, "BTF lingers")) {
- err = -1;
- goto done;
- }
fprintf(stderr, "OK");
Patches currently in stable-queue which might be from yonghong.song@xxxxxxxxx are
queue-6.6/libbpf-fix-potential-uninitialized-tail-padding-with.patch
queue-6.6/selftests-bpf-fix-compiler-warnings-in-release-1-mod.patch
queue-6.6/selftests-bpf-remove-flaky-test_btf_id-test.patch
queue-6.6/selftests-bpf-fix-pyperf180-compilation-failure-with.patch
queue-6.6/bpf-fix-a-few-selftest-failures-due-to-llvm18-change.patch
