mm/slub, kunit: Use inverted data to corrupt kmem cache
[ Upstream commit b1080c667b3b2c8c38a7fa83ca5567124887abae ]
Two failure patterns are seen randomly when running slub_kunit tests with
CONFIG_SLAB_FREELIST_RANDOM and CONFIG_SLAB_FREELIST_HARDENED enabled.
Pattern 1:
# test_clobber_zone: pass:1 fail:0 skip:0 total:1
ok 1 test_clobber_zone
# test_next_pointer: EXPECTATION FAILED at lib/slub_kunit.c:72
Expected 3 == slab_errors, but
slab_errors == 0 (0x0)
# test_next_pointer: EXPECTATION FAILED at lib/slub_kunit.c:84
Expected 2 == slab_errors, but
slab_errors == 0 (0x0)
# test_next_pointer: pass:0 fail:1 skip:0 total:1
not ok 2 test_next_pointer
In this case, test_next_pointer() overwrites p[s->offset], but the data
at p[s->offset] is already 0x12.
Pattern 2:
ok 1 test_clobber_zone
# test_next_pointer: EXPECTATION FAILED at lib/slub_kunit.c:72
Expected 3 == slab_errors, but
slab_errors == 2 (0x2)
# test_next_pointer: pass:0 fail:1 skip:0 total:1
not ok 2 test_next_pointer
In this case, p[s->offset] has a value other than 0x12, but one of the
expected failures is nevertheless missing.
Invert data instead of writing a fixed value to corrupt the cache data
structures to fix the problem.
Fixes: 1f9f78b1b376 ("mm/slub, kunit: add a KUnit test for SLUB debugging functionality")
Cc: Oliver Glitta <[email protected]>
Cc: Vlastimil Babka <[email protected]>
CC: Daniel Latypov <[email protected]>
Cc: Marco Elver <[email protected]>
Signed-off-by: Guenter Roeck <[email protected]>
Signed-off-by: Vlastimil Babka <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
1 file changed
