lkml.org 
[lkml]   [2021]   [Nov]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 29/31] kasan, arm64: allow KASAN_VMALLOC with HW_TAGS
Date
From: Andrey Konovalov <andreyknvl@google.com>

vmalloc tagging support for HW_TAGS KASAN is now complete.

Allow enabling CONFIG_KASAN_VMALLOC.

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.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
---
arch/arm64/Kconfig | 3 +--
lib/Kconfig.kasan | 20 ++++++++++----------
2 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index c05d7a06276f..5981e5460c51 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -205,8 +205,7 @@ config ARM64
select IOMMU_DMA if IOMMU_SUPPORT
select IRQ_DOMAIN
select IRQ_FORCED_THREADING
- select KASAN_VMALLOC if KASAN_GENERIC
- select KASAN_VMALLOC if KASAN_SW_TAGS
+ select KASAN_VMALLOC
select MODULES_USE_ELF_RELA
select NEED_DMA_MAP_STATE
select NEED_SG_DMA_LENGTH
diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan
index 3f144a87f8a3..7834c35a7964 100644
--- a/lib/Kconfig.kasan
+++ b/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 || KASAN_SW_TAGS) && 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
--
2.25.1
\
 
 \ /
  Last update: 2021-11-30 23:15    [W:0.435 / U:0.012 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site