kernel/linux.git/include/linux/kasan-enabled.h, branch v6.19.11

kasan: introduce ARCH_DEFER_KASAN and unify static key across modes

2025-09-21T21:21:58+00:00

Patch series "kasan: unify kasan_enabled() and remove arch-specific implementations", v6. This patch series 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. The core issue is that different architectures have inconsistent 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 (of 2): 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. Link: https://lkml.kernel.org/r/20250810125746.1105476-1-snovitoll@gmail.com Link: https://lkml.kernel.org/r/20250810125746.1105476-2-snovitoll@gmail.com Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217049 Signed-off-by: Sabyrzhan Tasbolatov Reviewed-by: Christophe Leroy Reviewed-by: Ritesh Harjani (IBM) #powerpc Cc: Alexander Gordeev Cc: Alexander Potapenko Cc: Alexandre Ghiti Cc: Alexandre Ghiti Cc: Andrey Konovalov Cc: Andrey Ryabinin Cc: Baoquan He Cc: David Gow Cc: Dmitriy Vyukov Cc: Heiko Carstens Cc: Huacai Chen Cc: Marco Elver Cc: Qing Zhang Cc: Sabyrzhan Tasbolatov Cc: Vincenzo Frascino Signed-off-by: Andrew Morton

kasan: fix a missing header include of static_keys.h

2022-03-09T12:13:37+00:00

The kasan-enabled.h header relies on static keys, so make sure to include the header to avoid compilation errors (with JUMP_LABEL=n). It fixes the following: ./include/linux/kasan-enabled.h:9:1: warning: data definition has no type or storage class 9 | DECLARE_STATIC_KEY_FALSE(kasan_flag_enabled); | ^~~~~~~~~~~~~~~~~~~~~~~~ error: type defaults to 'int' in declaration of 'DECLARE_STATIC_KEY_FALSE' [-Werror=implicit-int] Fixes: f9b5e46f4097eb29 ("kasan: split kasan_*enabled() functions into a separate header") Cc: Peter Collingbourne Cc: Mark Rutland Cc: Catalin Marinas Cc: Will Deacon Acked-by: Andrey Konovalov Signed-off-by: Joey Gouly Link: https://lore.kernel.org/r/20220301154518.19456-1-joey.gouly@arm.com Signed-off-by: Will Deacon

kasan: split kasan_*enabled() functions into a separate header

2022-02-22T21:48:44+00:00

In an upcoming commit we are going to need to call kasan_hw_tags_enabled() from arch/arm64/include/asm/mte.h. This would create a circular dependency between headers if KASAN_GENERIC or KASAN_SW_TAGS is enabled: linux/kasan.h -> linux/pgtable.h -> asm/pgtable.h -> asm/mte.h -> linux/kasan.h. Break the cycle by introducing a new header linux/kasan-enabled.h with the kasan_*enabled() functions that can be included from asm/mte.h. Link: https://linux-review.googlesource.com/id/I5b0d96c6ed0026fc790899e14d42b2fac6ab568e Signed-off-by: Peter Collingbourne Reviewed-by: Andrey Konovalov Link: https://lore.kernel.org/r/20220219012945.894950-1-pcc@google.com Signed-off-by: Will Deacon