Commit fbefb423 authored by Andrey Konovalov's avatar Andrey Konovalov Committed by Linus Torvalds
Browse files

kasan: allow enabling KASAN_VMALLOC and SW/HW_TAGS 

Allow enabling CONFIG_KASAN_VMALLOC with SW_TAGS and HW_TAGS KASAN modes.

Also adjust CONFIG_KASAN_VMALLOC description:

 - Mention HW_TAGS support.

 - Remove unneeded internal details: they have no place in Kconfig
   description and are already explained in the documentation.

Link: https://lkml.kernel.org/r/bfa0fdedfe25f65e5caa4e410f074ddbac7a0b59.1643047180.git.andreyknvl@google.com


Signed-off-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Acked-by: default avatarMarco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 551b2bcb

lib/Kconfig.kasan

+10 −10
Original line number Diff line number Diff line
@@ -178,17 +178,17 @@ config KASAN_TAGS_IDENTIFY 
	  memory consumption.



config KASAN_VMALLOC

	bool "Back mappings in vmalloc space with real shadow memory"

	depends on KASAN_GENERIC && HAVE_ARCH_KASAN_VMALLOC

	bool "Check accesses to vmalloc allocations"

	depends on HAVE_ARCH_KASAN_VMALLOC

	help

	  By default, the shadow region for vmalloc space is the read-only

	  zero page. This means that KASAN cannot detect errors involving

	  vmalloc space.



	  Enabling this option will hook in to vmap/vmalloc and back those

	  mappings with real shadow memory allocated on demand. This allows

	  for KASAN to detect more sorts of errors (and to support vmapped

	  stacks), but at the cost of higher memory usage.

	  This mode makes KASAN check accesses to vmalloc allocations for

	  validity.



	  With software KASAN modes, checking is done for all types of vmalloc

	  allocations. Enabling this option leads to higher memory usage.



	  With hardware tag-based KASAN, only VM_ALLOC mappings are checked.

	  There is no additional memory usage.



config KASAN_KUNIT_TEST

	tristate "KUnit-compatible tests of KASAN bug detection capabilities" if !KUNIT_ALL_TESTS