The patch titled Subject: kasan, arm64: only init shadow for software modes has been added to the -mm tree. Its filename is kasan-arm64-only-init-shadow-for-software-modes.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/kasan-arm64-only-init-shadow-for-software-modes.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/kasan-arm64-only-init-shadow-for-software-modes.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Subject: kasan, arm64: only init shadow for software modes This is a preparatory commit for the upcoming addition of a new hardware tag-based (MTE-based) KASAN mode. Hardware tag-based KASAN won't be using shadow memory. Only initialize it when one of the software KASAN modes are enabled. No functional changes for software modes. Link: https://lkml.kernel.org/r/3aae3b3f931618b4418af7992bff1e258e4eb1ad.1605046192.git.andreyknvl@xxxxxxxxxx Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Alexander Potapenko <glider@xxxxxxxxxx> Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx> Cc: Branislav Rankov <Branislav.Rankov@xxxxxxx> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Cc: Evgenii Stepanov <eugenis@xxxxxxxxxx> Cc: Kevin Brodsky <kevin.brodsky@xxxxxxx> Cc: Marco Elver <elver@xxxxxxxxxx> Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx> Cc: Will Deacon <will.deacon@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/arm64/include/asm/kasan.h | 8 ++++++-- arch/arm64/mm/kasan_init.c | 15 ++++++++++++++- 2 files changed, 20 insertions(+), 3 deletions(-) --- a/arch/arm64/include/asm/kasan.h~kasan-arm64-only-init-shadow-for-software-modes +++ a/arch/arm64/include/asm/kasan.h @@ -13,6 +13,12 @@ #define arch_kasan_get_tag(addr) __tag_get(addr) #ifdef CONFIG_KASAN +void kasan_init(void); +#else +static inline void kasan_init(void) { } +#endif + +#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) /* * KASAN_SHADOW_START: beginning of the kernel virtual addresses. @@ -33,12 +39,10 @@ #define _KASAN_SHADOW_START(va) (KASAN_SHADOW_END - (1UL << ((va) - KASAN_SHADOW_SCALE_SHIFT))) #define KASAN_SHADOW_START _KASAN_SHADOW_START(vabits_actual) -void kasan_init(void); void kasan_copy_shadow(pgd_t *pgdir); asmlinkage void kasan_early_init(void); #else -static inline void kasan_init(void) { } static inline void kasan_copy_shadow(pgd_t *pgdir) { } #endif --- a/arch/arm64/mm/kasan_init.c~kasan-arm64-only-init-shadow-for-software-modes +++ a/arch/arm64/mm/kasan_init.c @@ -21,6 +21,8 @@ #include <asm/sections.h> #include <asm/tlbflush.h> +#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) + static pgd_t tmp_pg_dir[PTRS_PER_PGD] __initdata __aligned(PGD_SIZE); /* @@ -208,7 +210,7 @@ static void __init clear_pgds(unsigned l set_pgd(pgd_offset_k(start), __pgd(0)); } -void __init kasan_init(void) +static void __init kasan_init_shadow(void) { u64 kimg_shadow_start, kimg_shadow_end; u64 mod_shadow_start, mod_shadow_end; @@ -269,6 +271,17 @@ void __init kasan_init(void) memset(kasan_early_shadow_page, KASAN_SHADOW_INIT, PAGE_SIZE); cpu_replace_ttbr1(lm_alias(swapper_pg_dir)); +} + +#else /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS) */ + +static inline void __init kasan_init_shadow(void) { } + +#endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */ + +void __init kasan_init(void) +{ + kasan_init_shadow(); /* At this point kasan is fully initialized. Enable error messages */ init_task.kasan_depth = 0; _ Patches currently in -mm which might be from andreyknvl@xxxxxxxxxx are kasan-drop-unnecessary-gpl-text-from-comment-headers.patch kasan-kasan_vmalloc-depends-on-kasan_generic.patch kasan-group-vmalloc-code.patch s390-kasan-include-asm-pageh-from-asm-kasanh.patch kasan-shadow-declarations-only-for-software-modes.patch kasan-rename-unpoison_shadow-to-unpoison_memory.patch kasan-rename-kasan_shadow_-to-kasan_granule_.patch kasan-only-build-initc-for-software-modes.patch kasan-split-out-shadowc-from-commonc.patch kasan-define-kasan_granule_page.patch kasan-rename-report-and-tags-files.patch kasan-dont-duplicate-config-dependencies.patch kasan-hide-invalid-free-check-implementation.patch kasan-decode-stack-frame-only-with-kasan_stack_enable.patch kasan-arm64-only-init-shadow-for-software-modes.patch kasan-arm64-only-use-kasan_depth-for-software-modes.patch kasan-arm64-move-initialization-message.patch kasan-arm64-rename-kasan_init_tags-and-mark-as-__init.patch kasan-rename-addr_has_shadow-to-addr_has_metadata.patch kasan-rename-print_shadow_for_address-to-print_memory_metadata.patch kasan-kasan_non_canonical_hook-only-for-software-modes.patch kasan-rename-shadow-layout-macros-to-meta.patch kasan-separate-metadata_fetch_row-for-each-mode.patch kasan-arm64-dont-allow-sw_tags-with-arm64_mte.patch kasan-introduce-config_kasan_hw_tags.patch arm64-kasan-align-allocations-for-hw_tags.patch arm64-kasan-add-arch-layer-for-memory-tagging-helpers.patch kasan-define-kasan_granule_size-for-hw_tags.patch kasan-x86-s390-update-undef-config_kasan.patch kasan-arm64-expand-config_kasan-checks.patch kasan-arm64-implement-hw_tags-runtime.patch kasan-arm64-print-report-from-tag-fault-handler.patch kasan-mm-reset-tags-when-accessing-metadata.patch kasan-arm64-enable-config_kasan_hw_tags.patch kasan-add-documentation-for-hardware-tag-based-mode.patch