On Wed, Sep 3, 2025 at 6:01 PM Andrey Konovalov <andreyk...@gmail.com> wrote: > > On Sun, Aug 10, 2025 at 2:58 PM Sabyrzhan Tasbolatov > <snovit...@gmail.com> wrote: > > > > Introduce CONFIG_ARCH_DEFER_KASAN to identify architectures [1] that need > > to defer KASAN initialization until shadow memory is properly set up, > > and unify the static key infrastructure across all KASAN modes. > > > > [1] PowerPC, UML, LoongArch selects ARCH_DEFER_KASAN. > > > > The core issue is that different architectures haveinconsistent approaches > > to KASAN readiness tracking: > > - PowerPC, LoongArch, and UML arch, each implement own > > kasan_arch_is_ready() > > - Only HW_TAGS mode had a unified static key (kasan_flag_enabled) > > - Generic and SW_TAGS modes relied on arch-specific solutions or always-on > > behavior > > > > This patch addresses the fragmentation in KASAN initialization > > across architectures by introducing a unified approach that eliminates > > duplicate static keys and arch-specific kasan_arch_is_ready() > > implementations. > > > > Let's replace kasan_arch_is_ready() with existing kasan_enabled() check, > > which examines the static key being enabled if arch selects > > ARCH_DEFER_KASAN or has HW_TAGS mode support. > > For other arch, kasan_enabled() checks the enablement during compile time. > > > > Now KASAN users can use a single kasan_enabled() check everywhere. > > > > Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217049 > > Signed-off-by: Sabyrzhan Tasbolatov <snovit...@gmail.com> > > --- > > Changes in v6: > > - Added more details in git commit message > > - Fixed commenting format per coding style in UML (Christophe Leroy) > > - Changed exporting to GPL for kasan_flag_enabled (Christophe Leroy) > > - Converted ARCH_DEFER_KASAN to def_bool depending on KASAN to avoid > > arch users to have `if KASAN` condition (Christophe Leroy) > > - Forgot to add __init for kasan_init in UML > > > > Changes in v5: > > - Unified patches where arch (powerpc, UML, loongarch) selects > > ARCH_DEFER_KASAN in the first patch not to break > > bisectability > > - Removed kasan_arch_is_ready completely as there is no user > > - Removed __wrappers in v4, left only those where it's necessary > > due to different implementations > > > > Changes in v4: > > - Fixed HW_TAGS static key functionality (was broken in v3) > > - Merged configuration and implementation for atomicity > > --- > > arch/loongarch/Kconfig | 1 + > > arch/loongarch/include/asm/kasan.h | 7 ------ > > arch/loongarch/mm/kasan_init.c | 8 +++---- > > arch/powerpc/Kconfig | 1 + > > arch/powerpc/include/asm/kasan.h | 12 ---------- > > arch/powerpc/mm/kasan/init_32.c | 2 +- > > arch/powerpc/mm/kasan/init_book3e_64.c | 2 +- > > arch/powerpc/mm/kasan/init_book3s_64.c | 6 +---- > > arch/um/Kconfig | 1 + > > arch/um/include/asm/kasan.h | 5 ++-- > > arch/um/kernel/mem.c | 13 ++++++++--- > > include/linux/kasan-enabled.h | 32 ++++++++++++++++++-------- > > include/linux/kasan.h | 6 +++++ > > lib/Kconfig.kasan | 12 ++++++++++ > > mm/kasan/common.c | 17 ++++++++++---- > > mm/kasan/generic.c | 19 +++++++++++---- > > mm/kasan/hw_tags.c | 9 +------- > > mm/kasan/kasan.h | 8 ++++++- > > mm/kasan/shadow.c | 12 +++++----- > > mm/kasan/sw_tags.c | 1 + > > mm/kasan/tags.c | 2 +- > > 21 files changed, 106 insertions(+), 70 deletions(-) > > > > diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig > > index f0abc38c40ac..e449e3fcecf9 100644 > > --- a/arch/loongarch/Kconfig > > +++ b/arch/loongarch/Kconfig > > @@ -9,6 +9,7 @@ config LOONGARCH > > select ACPI_PPTT if ACPI > > select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI > > select ARCH_BINFMT_ELF_STATE > > + select ARCH_NEEDS_DEFER_KASAN > > select ARCH_DISABLE_KASAN_INLINE > > select ARCH_ENABLE_MEMORY_HOTPLUG > > select ARCH_ENABLE_MEMORY_HOTREMOVE > > diff --git a/arch/loongarch/include/asm/kasan.h > > b/arch/loongarch/include/asm/kasan.h > > index 62f139a9c87d..0e50e5b5e056 100644 > > --- a/arch/loongarch/include/asm/kasan.h > > +++ b/arch/loongarch/include/asm/kasan.h > > @@ -66,7 +66,6 @@ > > #define XKPRANGE_WC_SHADOW_OFFSET (KASAN_SHADOW_START + > > XKPRANGE_WC_KASAN_OFFSET) > > #define XKVRANGE_VC_SHADOW_OFFSET (KASAN_SHADOW_START + > > XKVRANGE_VC_KASAN_OFFSET) > > > > -extern bool kasan_early_stage; > > extern unsigned char kasan_early_shadow_page[PAGE_SIZE]; > > > > #define kasan_mem_to_shadow kasan_mem_to_shadow > > @@ -75,12 +74,6 @@ void *kasan_mem_to_shadow(const void *addr); > > #define kasan_shadow_to_mem kasan_shadow_to_mem > > const void *kasan_shadow_to_mem(const void *shadow_addr); > > > > -#define kasan_arch_is_ready kasan_arch_is_ready > > -static __always_inline bool kasan_arch_is_ready(void) > > -{ > > - return !kasan_early_stage; > > -} > > - > > #define addr_has_metadata addr_has_metadata > > static __always_inline bool addr_has_metadata(const void *addr) > > { > > diff --git a/arch/loongarch/mm/kasan_init.c b/arch/loongarch/mm/kasan_init.c > > index d2681272d8f0..170da98ad4f5 100644 > > --- a/arch/loongarch/mm/kasan_init.c > > +++ b/arch/loongarch/mm/kasan_init.c > > @@ -40,11 +40,9 @@ static pgd_t kasan_pg_dir[PTRS_PER_PGD] __initdata > > __aligned(PAGE_SIZE); > > #define __pte_none(early, pte) (early ? pte_none(pte) : \ > > ((pte_val(pte) & _PFN_MASK) == (unsigned > > long)__pa(kasan_early_shadow_page))) > > > > -bool kasan_early_stage = true; > > - > > void *kasan_mem_to_shadow(const void *addr) > > { > > - if (!kasan_arch_is_ready()) { > > + if (!kasan_enabled()) { > > return (void *)(kasan_early_shadow_page); > > } else { > > unsigned long maddr = (unsigned long)addr; > > @@ -298,7 +296,8 @@ void __init kasan_init(void) > > kasan_populate_early_shadow(kasan_mem_to_shadow((void > > *)VMALLOC_START), > > kasan_mem_to_shadow((void > > *)KFENCE_AREA_END)); > > > > - kasan_early_stage = false; > > + /* Enable KASAN here before kasan_mem_to_shadow(). */ > > + kasan_init_generic(); > > > > /* Populate the linear mapping */ > > for_each_mem_range(i, &pa_start, &pa_end) { > > @@ -329,5 +328,4 @@ void __init kasan_init(void) > > > > /* At this point kasan is fully initialized. Enable error messages > > */ > > init_task.kasan_depth = 0; > > - pr_info("KernelAddressSanitizer initialized.\n"); > > } > > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig > > index 93402a1d9c9f..4730c676b6bf 100644 > > --- a/arch/powerpc/Kconfig > > +++ b/arch/powerpc/Kconfig > > @@ -122,6 +122,7 @@ config PPC > > # Please keep this list sorted alphabetically. > > # > > select ARCH_32BIT_OFF_T if PPC32 > > + select ARCH_NEEDS_DEFER_KASAN if PPC_RADIX_MMU > > select ARCH_DISABLE_KASAN_INLINE if PPC_RADIX_MMU > > select ARCH_DMA_DEFAULT_COHERENT if !NOT_COHERENT_CACHE > > select ARCH_ENABLE_MEMORY_HOTPLUG > > diff --git a/arch/powerpc/include/asm/kasan.h > > b/arch/powerpc/include/asm/kasan.h > > index b5bbb94c51f6..957a57c1db58 100644 > > --- a/arch/powerpc/include/asm/kasan.h > > +++ b/arch/powerpc/include/asm/kasan.h > > @@ -53,18 +53,6 @@ > > #endif > > > > #ifdef CONFIG_KASAN > > -#ifdef CONFIG_PPC_BOOK3S_64 > > -DECLARE_STATIC_KEY_FALSE(powerpc_kasan_enabled_key); > > - > > -static __always_inline bool kasan_arch_is_ready(void) > > -{ > > - if (static_branch_likely(&powerpc_kasan_enabled_key)) > > - return true; > > - return false; > > -} > > - > > -#define kasan_arch_is_ready kasan_arch_is_ready > > -#endif > > > > void kasan_early_init(void); > > void kasan_mmu_init(void); > > diff --git a/arch/powerpc/mm/kasan/init_32.c > > b/arch/powerpc/mm/kasan/init_32.c > > index 03666d790a53..1d083597464f 100644 > > --- a/arch/powerpc/mm/kasan/init_32.c > > +++ b/arch/powerpc/mm/kasan/init_32.c > > @@ -165,7 +165,7 @@ void __init kasan_init(void) > > > > /* At this point kasan is fully initialized. Enable error messages > > */ > > init_task.kasan_depth = 0; > > - pr_info("KASAN init done\n"); > > + kasan_init_generic(); > > } > > > > void __init kasan_late_init(void) > > diff --git a/arch/powerpc/mm/kasan/init_book3e_64.c > > b/arch/powerpc/mm/kasan/init_book3e_64.c > > index 60c78aac0f63..0d3a73d6d4b0 100644 > > --- a/arch/powerpc/mm/kasan/init_book3e_64.c > > +++ b/arch/powerpc/mm/kasan/init_book3e_64.c > > @@ -127,7 +127,7 @@ void __init kasan_init(void) > > > > /* Enable error messages */ > > init_task.kasan_depth = 0; > > - pr_info("KASAN init done\n"); > > + kasan_init_generic(); > > } > > > > void __init kasan_late_init(void) { } > > diff --git a/arch/powerpc/mm/kasan/init_book3s_64.c > > b/arch/powerpc/mm/kasan/init_book3s_64.c > > index 7d959544c077..dcafa641804c 100644 > > --- a/arch/powerpc/mm/kasan/init_book3s_64.c > > +++ b/arch/powerpc/mm/kasan/init_book3s_64.c > > @@ -19,8 +19,6 @@ > > #include <linux/memblock.h> > > #include <asm/pgalloc.h> > > > > -DEFINE_STATIC_KEY_FALSE(powerpc_kasan_enabled_key); > > - > > static void __init kasan_init_phys_region(void *start, void *end) > > { > > unsigned long k_start, k_end, k_cur; > > @@ -92,11 +90,9 @@ void __init kasan_init(void) > > */ > > memset(kasan_early_shadow_page, 0, PAGE_SIZE); > > > > - static_branch_inc(&powerpc_kasan_enabled_key); > > - > > /* Enable error messages */ > > init_task.kasan_depth = 0; > > - pr_info("KASAN init done\n"); > > + kasan_init_generic(); > > } > > > > void __init kasan_early_init(void) { } > > diff --git a/arch/um/Kconfig b/arch/um/Kconfig > > index 9083bfdb7735..1d4def0db841 100644 > > --- a/arch/um/Kconfig > > +++ b/arch/um/Kconfig > > @@ -5,6 +5,7 @@ menu "UML-specific options" > > config UML > > bool > > default y > > + select ARCH_NEEDS_DEFER_KASAN if STATIC_LINK > > select ARCH_WANTS_DYNAMIC_TASK_STRUCT > > select ARCH_HAS_CACHE_LINE_SIZE > > select ARCH_HAS_CPU_FINALIZE_INIT > > diff --git a/arch/um/include/asm/kasan.h b/arch/um/include/asm/kasan.h > > index f97bb1f7b851..b54a4e937fd1 100644 > > --- a/arch/um/include/asm/kasan.h > > +++ b/arch/um/include/asm/kasan.h > > @@ -24,10 +24,9 @@ > > > > #ifdef CONFIG_KASAN > > void kasan_init(void); > > -extern int kasan_um_is_ready; > > > > -#ifdef CONFIG_STATIC_LINK > > -#define kasan_arch_is_ready() (kasan_um_is_ready) > > +#if defined(CONFIG_STATIC_LINK) && defined(CONFIG_KASAN_INLINE) > > +#error UML does not work in KASAN_INLINE mode with STATIC_LINK enabled! > > #endif > > #else > > static inline void kasan_init(void) { } > > diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c > > index 76bec7de81b5..32e3b1972dc1 100644 > > --- a/arch/um/kernel/mem.c > > +++ b/arch/um/kernel/mem.c > > @@ -21,10 +21,10 @@ > > #include <os.h> > > #include <um_malloc.h> > > #include <linux/sched/task.h> > > +#include <linux/kasan.h> > > > > #ifdef CONFIG_KASAN > > -int kasan_um_is_ready; > > -void kasan_init(void) > > +void __init kasan_init(void) > > { > > /* > > * kasan_map_memory will map all of the required address space and > > @@ -32,7 +32,11 @@ void kasan_init(void) > > */ > > kasan_map_memory((void *)KASAN_SHADOW_START, KASAN_SHADOW_SIZE); > > init_task.kasan_depth = 0; > > - kasan_um_is_ready = true; > > + /* > > + * Since kasan_init() is called before main(), > > + * KASAN is initialized but the enablement is deferred after > > + * jump_label_init(). See arch_mm_preinit(). > > + */ > > } > > > > static void (*kasan_init_ptr)(void) > > @@ -58,6 +62,9 @@ static unsigned long brk_end; > > > > void __init arch_mm_preinit(void) > > { > > + /* Safe to call after jump_label_init(). Enables KASAN. */ > > + kasan_init_generic(); > > + > > /* clear the zero-page */ > > memset(empty_zero_page, 0, PAGE_SIZE); > > > > diff --git a/include/linux/kasan-enabled.h b/include/linux/kasan-enabled.h > > index 6f612d69ea0c..9eca967d8526 100644 > > --- a/include/linux/kasan-enabled.h > > +++ b/include/linux/kasan-enabled.h > > @@ -4,32 +4,46 @@ > > > > #include <linux/static_key.h> > > > > -#ifdef CONFIG_KASAN_HW_TAGS > > - > > +#if defined(CONFIG_ARCH_DEFER_KASAN) || defined(CONFIG_KASAN_HW_TAGS) > > +/* > > + * Global runtime flag for KASAN modes that need runtime control. > > + * Used by ARCH_DEFER_KASAN architectures and HW_TAGS mode. > > + */ > > DECLARE_STATIC_KEY_FALSE(kasan_flag_enabled); > > > > +/* > > + * Runtime control for shadow memory initialization or HW_TAGS mode. > > + * Uses static key for architectures that need deferred KASAN or HW_TAGS. > > + */ > > static __always_inline bool kasan_enabled(void) > > { > > return static_branch_likely(&kasan_flag_enabled); > > } > > > > -static inline bool kasan_hw_tags_enabled(void) > > +static inline void kasan_enable(void) > > { > > - return kasan_enabled(); > > + static_branch_enable(&kasan_flag_enabled); > > } > > - > > -#else /* CONFIG_KASAN_HW_TAGS */ > > - > > -static inline bool kasan_enabled(void) > > +#else > > +/* For architectures that can enable KASAN early, use compile-time check. > > */ > > +static __always_inline bool kasan_enabled(void) > > { > > return IS_ENABLED(CONFIG_KASAN); > > } > > > > +static inline void kasan_enable(void) {} > > +#endif /* CONFIG_ARCH_DEFER_KASAN || CONFIG_KASAN_HW_TAGS */ > > + > > +#ifdef CONFIG_KASAN_HW_TAGS > > +static inline bool kasan_hw_tags_enabled(void) > > +{ > > + return kasan_enabled(); > > +} > > +#else > > static inline bool kasan_hw_tags_enabled(void) > > { > > return false; > > } > > - > > #endif /* CONFIG_KASAN_HW_TAGS */ > > > > #endif /* LINUX_KASAN_ENABLED_H */ > > diff --git a/include/linux/kasan.h b/include/linux/kasan.h > > index 890011071f2b..51a8293d1af6 100644 > > --- a/include/linux/kasan.h > > +++ b/include/linux/kasan.h > > @@ -543,6 +543,12 @@ void kasan_report_async(void); > > > > #endif /* CONFIG_KASAN_HW_TAGS */ > > > > +#ifdef CONFIG_KASAN_GENERIC > > +void __init kasan_init_generic(void); > > +#else > > +static inline void kasan_init_generic(void) { } > > +#endif > > + > > #ifdef CONFIG_KASAN_SW_TAGS > > void __init kasan_init_sw_tags(void); > > #else > > diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan > > index f82889a830fa..a4bb610a7a6f 100644 > > --- a/lib/Kconfig.kasan > > +++ b/lib/Kconfig.kasan > > @@ -19,6 +19,18 @@ config ARCH_DISABLE_KASAN_INLINE > > Disables both inline and stack instrumentation. Selected by > > architectures that do not support these instrumentation types. > > > > +config ARCH_NEEDS_DEFER_KASAN > > + bool > > + > > +config ARCH_DEFER_KASAN > > + def_bool y > > + depends on KASAN && ARCH_NEEDS_DEFER_KASAN > > + help > > + Architectures should select this if they need to defer KASAN > > + initialization until shadow memory is properly set up. This > > + enables runtime control via static keys. Otherwise, KASAN uses > > + compile-time constants for better performance. > > + > > config CC_HAS_KASAN_GENERIC > > def_bool $(cc-option, -fsanitize=kernel-address) > > > > diff --git a/mm/kasan/common.c b/mm/kasan/common.c > > index 9142964ab9c9..e3765931a31f 100644 > > --- a/mm/kasan/common.c > > +++ b/mm/kasan/common.c > > @@ -32,6 +32,15 @@ > > #include "kasan.h" > > #include "../slab.h" > > > > +#if defined(CONFIG_ARCH_DEFER_KASAN) || defined(CONFIG_KASAN_HW_TAGS) > > +/* > > + * Definition of the unified static key declared in kasan-enabled.h. > > + * This provides consistent runtime enable/disable across KASAN modes. > > + */ > > +DEFINE_STATIC_KEY_FALSE(kasan_flag_enabled); > > +EXPORT_SYMBOL_GPL(kasan_flag_enabled); > > +#endif > > + > > struct slab *kasan_addr_to_slab(const void *addr) > > { > > if (virt_addr_valid(addr)) > > @@ -246,7 +255,7 @@ static inline void poison_slab_object(struct kmem_cache > > *cache, void *object, > > bool __kasan_slab_pre_free(struct kmem_cache *cache, void *object, > > unsigned long ip) > > { > > - if (!kasan_arch_is_ready() || is_kfence_address(object)) > > + if (is_kfence_address(object)) > > return false; > > Why is the check removed here and in some other places below? This > need to be explained in the commit message.
kasan_arch_is_ready which was unified with kasan_enabled, was removed here because __kasan_slab_pre_free is called from include/linux/kasan.h [1] where there's already kasan_enabled() check. [1] https://elixir.bootlin.com/linux/v6.16.7/source/include/linux/kasan.h#L198 Please let me know if v7 is required with the change in the git commit message only. > > > return check_slab_allocation(cache, object, ip); > > } > > @@ -254,7 +263,7 @@ bool __kasan_slab_pre_free(struct kmem_cache *cache, > > void *object, > > bool __kasan_slab_free(struct kmem_cache *cache, void *object, bool init, > > bool still_accessible) > > { > > - if (!kasan_arch_is_ready() || is_kfence_address(object)) > > + if (is_kfence_address(object)) > > return false; > > > > /* > > @@ -293,7 +302,7 @@ bool __kasan_slab_free(struct kmem_cache *cache, void > > *object, bool init, > > > > static inline bool check_page_allocation(void *ptr, unsigned long ip) > > { > > - if (!kasan_arch_is_ready()) > > + if (!kasan_enabled()) > > return false; > > > > if (ptr != page_address(virt_to_head_page(ptr))) { > > @@ -522,7 +531,7 @@ bool __kasan_mempool_poison_object(void *ptr, unsigned > > long ip) > > return true; > > } > > > > - if (is_kfence_address(ptr) || !kasan_arch_is_ready()) > > + if (is_kfence_address(ptr)) > > return true; > > > > slab = folio_slab(folio); > > diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c > > index d54e89f8c3e7..b413c46b3e04 100644 > > --- a/mm/kasan/generic.c > > +++ b/mm/kasan/generic.c > > @@ -36,6 +36,17 @@ > > #include "kasan.h" > > #include "../slab.h" > > > > +/* > > + * Initialize Generic KASAN and enable runtime checks. > > + * This should be called from arch kasan_init() once shadow memory is > > ready. > > + */ > > +void __init kasan_init_generic(void) > > +{ > > + kasan_enable(); > > + > > + pr_info("KernelAddressSanitizer initialized (generic)\n"); > > +} > > + > > /* > > * All functions below always inlined so compiler could > > * perform better optimizations in each of __asan_loadX/__assn_storeX > > @@ -165,7 +176,7 @@ static __always_inline bool check_region_inline(const > > void *addr, > > size_t size, bool write, > > unsigned long ret_ip) > > { > > - if (!kasan_arch_is_ready()) > > + if (!kasan_enabled()) > > return true; > > > > if (unlikely(size == 0)) > > @@ -193,7 +204,7 @@ bool kasan_byte_accessible(const void *addr) > > { > > s8 shadow_byte; > > > > - if (!kasan_arch_is_ready()) > > + if (!kasan_enabled()) > > return true; > > > > shadow_byte = READ_ONCE(*(s8 *)kasan_mem_to_shadow(addr)); > > @@ -495,7 +506,7 @@ static void release_alloc_meta(struct kasan_alloc_meta > > *meta) > > > > static void release_free_meta(const void *object, struct kasan_free_meta > > *meta) > > { > > - if (!kasan_arch_is_ready()) > > + if (!kasan_enabled()) > > return; > > > > /* Check if free meta is valid. */ > > @@ -562,7 +573,7 @@ void kasan_save_alloc_info(struct kmem_cache *cache, > > void *object, gfp_t flags) > > kasan_save_track(&alloc_meta->alloc_track, flags); > > } > > > > -void kasan_save_free_info(struct kmem_cache *cache, void *object) > > +void __kasan_save_free_info(struct kmem_cache *cache, void *object) > > { > > struct kasan_free_meta *free_meta; > > > > diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c > > index 9a6927394b54..c8289a3feabf 100644 > > --- a/mm/kasan/hw_tags.c > > +++ b/mm/kasan/hw_tags.c > > @@ -45,13 +45,6 @@ static enum kasan_arg kasan_arg __ro_after_init; > > static enum kasan_arg_mode kasan_arg_mode __ro_after_init; > > static enum kasan_arg_vmalloc kasan_arg_vmalloc __initdata; > > > > -/* > > - * Whether KASAN is enabled at all. > > - * The value remains false until KASAN is initialized by > > kasan_init_hw_tags(). > > - */ > > -DEFINE_STATIC_KEY_FALSE(kasan_flag_enabled); > > -EXPORT_SYMBOL(kasan_flag_enabled); > > - > > /* > > * Whether the selected mode is synchronous, asynchronous, or asymmetric. > > * Defaults to KASAN_MODE_SYNC. > > @@ -260,7 +253,7 @@ void __init kasan_init_hw_tags(void) > > kasan_init_tags(); > > > > /* KASAN is now initialized, enable it. */ > > - static_branch_enable(&kasan_flag_enabled); > > + kasan_enable(); > > > > pr_info("KernelAddressSanitizer initialized (hw-tags, mode=%s, > > vmalloc=%s, stacktrace=%s)\n", > > kasan_mode_info(), > > diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h > > index 129178be5e64..8a9d8a6ea717 100644 > > --- a/mm/kasan/kasan.h > > +++ b/mm/kasan/kasan.h > > @@ -398,7 +398,13 @@ depot_stack_handle_t kasan_save_stack(gfp_t flags, > > depot_flags_t depot_flags); > > void kasan_set_track(struct kasan_track *track, depot_stack_handle_t > > stack); > > void kasan_save_track(struct kasan_track *track, gfp_t flags); > > void kasan_save_alloc_info(struct kmem_cache *cache, void *object, gfp_t > > flags); > > -void kasan_save_free_info(struct kmem_cache *cache, void *object); > > + > > +void __kasan_save_free_info(struct kmem_cache *cache, void *object); > > +static inline void kasan_save_free_info(struct kmem_cache *cache, void > > *object) > > +{ > > + if (kasan_enabled()) > > + __kasan_save_free_info(cache, object); > > +} > > What I meant with these __wrappers was that we should add them for the > KASAN hooks that are called from non-KASAN code (i.e. for the hooks > defined in include/linux/kasan.h). And then move all the > kasan_enabled() checks from mm/kasan/* to where the wrappers are > defined in include/linux/kasan.h (see kasan_unpoison_range() as an > example). > > kasan_save_free_info is a KASAN internal function that should need > such a wrapper. > > For now, to make these patches simpler, you can keep kasan_enabled() > checks in mm/kasan/*, where they are now. Later we can move them to > include/linux/kasan.h with a separate patch. Yes, I'd like to revisit this in the next separate patch series. > > > > > > #ifdef CONFIG_KASAN_GENERIC > > bool kasan_quarantine_put(struct kmem_cache *cache, void *object); > > diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c > > index d2c70cd2afb1..2e126cb21b68 100644 > > --- a/mm/kasan/shadow.c > > +++ b/mm/kasan/shadow.c > > @@ -125,7 +125,7 @@ void kasan_poison(const void *addr, size_t size, u8 > > value, bool init) > > { > > void *shadow_start, *shadow_end; > > > > - if (!kasan_arch_is_ready()) > > + if (!kasan_enabled()) > > return; > > > > /* > > @@ -150,7 +150,7 @@ EXPORT_SYMBOL_GPL(kasan_poison); > > #ifdef CONFIG_KASAN_GENERIC > > void kasan_poison_last_granule(const void *addr, size_t size) > > { > > - if (!kasan_arch_is_ready()) > > + if (!kasan_enabled()) > > return; > > > > if (size & KASAN_GRANULE_MASK) { > > @@ -390,7 +390,7 @@ int kasan_populate_vmalloc(unsigned long addr, unsigned > > long size) > > unsigned long shadow_start, shadow_end; > > int ret; > > > > - if (!kasan_arch_is_ready()) > > + if (!kasan_enabled()) > > return 0; > > > > if (!is_vmalloc_or_module_addr((void *)addr)) > > @@ -560,7 +560,7 @@ void kasan_release_vmalloc(unsigned long start, > > unsigned long end, > > unsigned long region_start, region_end; > > unsigned long size; > > > > - if (!kasan_arch_is_ready()) > > + if (!kasan_enabled()) > > return; > > > > region_start = ALIGN(start, KASAN_MEMORY_PER_SHADOW_PAGE); > > @@ -611,7 +611,7 @@ void *__kasan_unpoison_vmalloc(const void *start, > > unsigned long size, > > * with setting memory tags, so the KASAN_VMALLOC_INIT flag is > > ignored. > > */ > > > > - if (!kasan_arch_is_ready()) > > + if (!kasan_enabled()) > > return (void *)start; > > > > if (!is_vmalloc_or_module_addr(start)) > > @@ -636,7 +636,7 @@ void *__kasan_unpoison_vmalloc(const void *start, > > unsigned long size, > > */ > > void __kasan_poison_vmalloc(const void *start, unsigned long size) > > { > > - if (!kasan_arch_is_ready()) > > + if (!kasan_enabled()) > > return; > > > > if (!is_vmalloc_or_module_addr(start)) > > diff --git a/mm/kasan/sw_tags.c b/mm/kasan/sw_tags.c > > index b9382b5b6a37..c75741a74602 100644 > > --- a/mm/kasan/sw_tags.c > > +++ b/mm/kasan/sw_tags.c > > @@ -44,6 +44,7 @@ void __init kasan_init_sw_tags(void) > > per_cpu(prng_state, cpu) = (u32)get_cycles(); > > > > kasan_init_tags(); > > + kasan_enable(); > > > > pr_info("KernelAddressSanitizer initialized (sw-tags, > > stacktrace=%s)\n", > > str_on_off(kasan_stack_collection_enabled())); > > diff --git a/mm/kasan/tags.c b/mm/kasan/tags.c > > index d65d48b85f90..b9f31293622b 100644 > > --- a/mm/kasan/tags.c > > +++ b/mm/kasan/tags.c > > @@ -142,7 +142,7 @@ void kasan_save_alloc_info(struct kmem_cache *cache, > > void *object, gfp_t flags) > > save_stack_info(cache, object, flags, false); > > } > > > > -void kasan_save_free_info(struct kmem_cache *cache, void *object) > > +void __kasan_save_free_info(struct kmem_cache *cache, void *object) > > { > > save_stack_info(cache, object, 0, true); > > } > > -- > > 2.34.1 > >
