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FROMGIT: kasan, mm: integrate slab init_on_alloc with HW_TAGS

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This change uses the previously added memory initialization feature of
HW_TAGS KASAN routines for slab memory when init_on_alloc is enabled.

With this change, memory initialization memset() is no longer called when
both HW_TAGS KASAN and init_on_alloc are enabled.  Instead, memory is
initialized in KASAN runtime.

The memory initialization memset() is moved into slab_post_alloc_hook()
that currently directly follows the initialization loop.  A new argument
is added to slab_post_alloc_hook() that indicates whether to initialize
the memory or not.

To avoid discrepancies with which memory gets initialized that can be
caused by future changes, both KASAN hook and initialization memset() are
put together and a warning comment is added.

Combining setting allocation tags with memory initialization improves
HW_TAGS KASAN performance when init_on_alloc is enabled.

Link: https://lkml.kernel.org/r/c1292aeb5d519da221ec74a0684a949b027d7720.1615296150.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

(cherry picked from commit c7948d4407ed85251c6de1a09589e69e4072abb4
 https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git akpm)
Bug: 182930667
Signed-off-by: Alexander Potapenko <glider@google.com>
Change-Id: I257917062e2cc5bfb3dbb46508200c30631a00a3
This commit is contained in:
Andrey Konovalov
2021-03-18 17:01:41 +11:00
committed by Todd Kjos
parent a15989497e
commit 5a7af11e34
5 changed files with 43 additions and 41 deletions
Download Patch File Download Diff File Expand all files Collapse all files

17
mm/slab.h
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@@ -556,15 +556,24 @@ static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
}
static inline void slab_post_alloc_hook(struct kmem_cache *s,
struct obj_cgroup *objcg,
gfp_t flags, size_t size, void **p)
struct obj_cgroup *objcg, gfp_t flags,
size_t size, void **p, bool init)
{
size_t i;
flags &= gfp_allowed_mask;
/*
* As memory initialization might be integrated into KASAN,
* kasan_slab_alloc and initialization memset must be
* kept together to avoid discrepancies in behavior.
*
* As p[i] might get tagged, memset and kmemleak hook come after KASAN.
*/
for (i = 0; i < size; i++) {
p[i] = kasan_slab_alloc(s, p[i], flags);
/* As p[i] might get tagged, call kmemleak hook after KASAN. */
p[i] = kasan_slab_alloc(s, p[i], flags, init);
if (p[i] && init && !kasan_has_integrated_init())
memset(p[i], 0, s->object_size);
kmemleak_alloc_recursive(p[i], s->object_size, 1,
s->flags, flags);
}