6.18-stable review patch. If anyone has any objections, please let me know.
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From: Matt Bobrowski mattbobrowski@google.com
[ Upstream commit d088da904223e8f5e19c6d156cf372d5baec1a7c ]
subtest_kmem_cache_iter_check_slabinfo() fundamentally compares slab cache names parsed out from /proc/slabinfo against those stored within struct kmem_cache_result. The current problem is that the slab cache name within struct kmem_cache_result is stored within a bounded fixed-length array (sized to SLAB_NAME_MAX(32)), whereas the name parsed out from /proc/slabinfo is not. Meaning, using ASSERT_STREQ() can certainly lead to test failures, particularly when dealing with slab cache names that are longer than SLAB_NAME_MAX(32) bytes. Notably, kmem_cache_create() allows callers to create slab caches with somewhat arbitrarily sized names via its __name identifier argument, so exceeding the SLAB_NAME_MAX(32) limit that is in place now can certainly happen.
Make subtest_kmem_cache_iter_check_slabinfo() more reliable by only checking up to sizeof(struct kmem_cache_result.name) - 1 using ASSERT_STRNEQ().
Fixes: a496d0cdc84d ("selftests/bpf: Add a test for kmem_cache_iter") Signed-off-by: Matt Bobrowski mattbobrowski@google.com Signed-off-by: Martin KaFai Lau martin.lau@kernel.org Acked-by: Song Liu song@kernel.org Link: https://patch.msgid.link/20251118073734.4188710-1-mattbobrowski@google.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/testing/selftests/bpf/prog_tests/kmem_cache_iter.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/kmem_cache_iter.c b/tools/testing/selftests/bpf/prog_tests/kmem_cache_iter.c index 1de14b111931a..6e35e13c20220 100644 --- a/tools/testing/selftests/bpf/prog_tests/kmem_cache_iter.c +++ b/tools/testing/selftests/bpf/prog_tests/kmem_cache_iter.c @@ -57,7 +57,8 @@ static void subtest_kmem_cache_iter_check_slabinfo(struct kmem_cache_iter *skel) if (!ASSERT_OK(ret, "kmem_cache_lookup")) break;
- ASSERT_STREQ(r.name, name, "kmem_cache_name"); + ASSERT_STRNEQ(r.name, name, sizeof(r.name) - 1, + "kmem_cache_name"); ASSERT_EQ(r.obj_size, objsize, "kmem_cache_objsize");
seen++;