Commit d088da90 authored by Matt Bobrowski's avatar Matt Bobrowski Committed by Martin KaFai Lau
Browse files

selftests/bpf: Use ASSERT_STRNEQ to factor in long slab cache names 



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: a496d0cd ("selftests/bpf: Add a test for kmem_cache_iter")
Signed-off-by: default avatarMatt Bobrowski <mattbobrowski@google.com>
Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
Acked-by: default avatarSong Liu <song@kernel.org>
Link: https://patch.msgid.link/20251118073734.4188710-1-mattbobrowski@google.com
parent d6ec0906

tools/testing/selftests/bpf/prog_tests/kmem_cache_iter.c

+2 −1
Original line number Diff line number Diff line
@@ -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++;