From: Andrey Konovalov <andreyknvl@xxxxxxxxxx> 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@xxxxxxxxxx> --- 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
