diff mbox series

[065/114] kasan: allow enabling KASAN_VMALLOC and SW/HW_TAGS

Message ID 20220325011150.D2817C340EC@smtp.kernel.org (mailing list archive)
State New
Headers show
Series [001/114] tools/vm/page_owner_sort.c: sort by stacktrace before culling | expand

Commit Message

Andrew Morton March 25, 2022, 1:11 a.m. UTC 
From: Andrey Konovalov <andreyknvl@google.com>
Subject: 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: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Marco 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: Andrew Morton <akpm@linux-foundation.org>
---

 lib/Kconfig.kasan |   18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)
diff mbox series

Patch

--- a/lib/Kconfig.kasan~kasan-allow-enabling-kasan_vmalloc-and-sw-hw_tags
+++ a/lib/Kconfig.kasan
@@ -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.
+	  This mode makes KASAN check accesses to vmalloc allocations for
+	  validity.
 
-	  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.
+	  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