[PATCH mm v4 36/39] kasan: allow enabling KASAN_VMALLOC and SW/HW_TAGS
From: <hidden>
Date: 2021-12-20 22:03:40
Also in:
linux-arm-kernel, lkml
Subsystem:
kasan, library code, the rest · Maintainers:
Andrey Ryabinin, Andrew Morton, Linus Torvalds
From: Andrey Konovalov <redacted> 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. Signed-off-by: Andrey Konovalov <redacted> --- lib/Kconfig.kasan | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-)
diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan
index 879757b6dd14..1f3e620188a2 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 && 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
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2.25.1