]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
kasan, mm: optimize krealloc poisoning
authorAndrey Konovalov <andreyknvl@google.com>
Fri, 26 Feb 2021 01:20:23 +0000 (17:20 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 26 Feb 2021 17:41:03 +0000 (09:41 -0800)
commitd12d9ad816299052385bac351fad338a073121b3
treedb54aa89690c94d390c02ed4a85d46be251f3cfa
parent26a5ca7a73be31f76c291465680517cde37051ca
kasan, mm: optimize krealloc poisoning

Currently, krealloc() always calls ksize(), which unpoisons the whole
object including the redzone.  This is inefficient, as kasan_krealloc()
repoisons the redzone for objects that fit into the same buffer.

This patch changes krealloc() instrumentation to use uninstrumented
__ksize() that doesn't unpoison the memory.  Instead, kasan_kreallos() is
changed to unpoison the memory excluding the redzone.

For objects that don't fit into the old allocation, this patch disables
KASAN accessibility checks when copying memory into a new object instead
of unpoisoning it.

Link: https://lkml.kernel.org/r/9bef90327c9cb109d736c40115684fd32f49e6b0.1612546384.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: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/kasan/common.c
mm/slab_common.c