kasan, arm64: add brk handler for inline instrumentation
authorAndrey Konovalov <andreyknvl@google.com>
Fri, 28 Dec 2018 08:30:54 +0000 (00:30 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 28 Dec 2018 20:11:44 +0000 (12:11 -0800)
commit41eea9cd239c5b3fff726894f85c97f60e5799a3
tree1a22d8495f8f69d9baa8916d347e50178dc00a6c
parent7f94ffbc4c6a1bdb51d39965e4f2acaa19bd798f
kasan, arm64: add brk handler for inline instrumentation

Tag-based KASAN inline instrumentation mode (which embeds checks of shadow
memory into the generated code, instead of inserting a callback) generates
a brk instruction when a tag mismatch is detected.

This commit adds a tag-based KASAN specific brk handler, that decodes the
immediate value passed to the brk instructions (to extract information
about the memory access that triggered the mismatch), reads the register
values (x0 contains the guilty address) and reports the bug.

Link: http://lkml.kernel.org/r/c91fe7684070e34dc34b419e6b69498f4dcacc2d.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
arch/arm64/include/asm/brk-imm.h
arch/arm64/kernel/traps.c
include/linux/kasan.h