diff options
| author | Marco Elver <elver@google.com> | 2022-04-14 19:13:40 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-04-15 14:49:55 -0700 |
| commit | 2dfe63e61cc31ee59ce951672b0850b5229cd5b0 (patch) | |
| tree | 9194074ed5008747db7b6a0aed068751d8b50b20 /mm/slab_common.c | |
| parent | b1add418d457bc30cdd6a89c2bba092cd8941fcf (diff) | |
| download | lwn-2dfe63e61cc31ee59ce951672b0850b5229cd5b0.tar.gz lwn-2dfe63e61cc31ee59ce951672b0850b5229cd5b0.zip | |
mm, kfence: support kmem_dump_obj() for KFENCE objects
Calling kmem_obj_info() via kmem_dump_obj() on KFENCE objects has been
producing garbage data due to the object not actually being maintained
by SLAB or SLUB.
Fix this by implementing __kfence_obj_info() that copies relevant
information to struct kmem_obj_info when the object was allocated by
KFENCE; this is called by a common kmem_obj_info(), which also calls the
slab/slub/slob specific variant now called __kmem_obj_info().
For completeness, kmem_dump_obj() now displays if the object was
allocated by KFENCE.
Link: https://lore.kernel.org/all/20220323090520.GG16885@xsang-OptiPlex-9020/
Link: https://lkml.kernel.org/r/20220406131558.3558585-1-elver@google.com
Fixes: b89fb5ef0ce6 ("mm, kfence: insert KFENCE hooks for SLUB")
Fixes: d3fb45f370d9 ("mm, kfence: insert KFENCE hooks for SLAB")
Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz> [slab]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/slab_common.c')
| -rw-r--r-- | mm/slab_common.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/mm/slab_common.c b/mm/slab_common.c index 6ee64d6208b3..2b3206a2c3b5 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -555,6 +555,13 @@ bool kmem_valid_obj(void *object) } EXPORT_SYMBOL_GPL(kmem_valid_obj); +static void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab) +{ + if (__kfence_obj_info(kpp, object, slab)) + return; + __kmem_obj_info(kpp, object, slab); +} + /** * kmem_dump_obj - Print available slab provenance information * @object: slab object for which to find provenance information. @@ -590,6 +597,8 @@ void kmem_dump_obj(void *object) pr_cont(" slab%s %s", cp, kp.kp_slab_cache->name); else pr_cont(" slab%s", cp); + if (is_kfence_address(object)) + pr_cont(" (kfence)"); if (kp.kp_objp) pr_cont(" start %px", kp.kp_objp); if (kp.kp_data_offset) |