From: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Subject: kasan: allow VMAP_STACK for HW_TAGS mode Even though hardware tag-based mode currently doesn't support checking vmalloc allocations, it doesn't use shadow memory and works with VMAP_STACK as is. Change VMAP_STACK definition accordingly. Link: https://lkml.kernel.org/r/ecdb2a1658ebd88eb276dee2493518ac0e82de41.1606162397.git.andreyknvl@xxxxxxxxxx Link: https://linux-review.googlesource.com/id/I3552cbc12321dec82cd7372676e9372a2eb452ac Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Reviewed-by: Marco Elver <elver@xxxxxxxxxx> Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx> Reviewed-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Tested-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> Cc: Alexander Potapenko <glider@xxxxxxxxxx> Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx> Cc: Branislav Rankov <Branislav.Rankov@xxxxxxx> Cc: Evgenii Stepanov <eugenis@xxxxxxxxxx> Cc: Kevin Brodsky <kevin.brodsky@xxxxxxx> Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx> Cc: Will Deacon <will.deacon@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/Kconfig | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/arch/Kconfig~kasan-allow-vmap_stack-for-hw_tags-mode +++ a/arch/Kconfig @@ -976,16 +976,16 @@ config VMAP_STACK default y bool "Use a virtually-mapped stack" depends on HAVE_ARCH_VMAP_STACK - depends on !KASAN || KASAN_VMALLOC + depends on !KASAN || KASAN_HW_TAGS || KASAN_VMALLOC help Enable this if you want the use virtually-mapped kernel stacks with guard pages. This causes kernel stack overflows to be caught immediately rather than causing difficult-to-diagnose corruption. - To use this with KASAN, the architecture must support backing - virtual mappings with real shadow memory, and KASAN_VMALLOC must - be enabled. + To use this with software KASAN modes, the architecture must support + backing virtual mappings with real shadow memory, and KASAN_VMALLOC + must be enabled. config ARCH_OPTIONAL_KERNEL_RWX def_bool n _
