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path: root/include/linux/kasan-enabled.h
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2025-09-21kasan: introduce ARCH_DEFER_KASAN and unify static key across modesSabyrzhan Tasbolatov
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 <snovitoll@gmail.com> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> #powerpc Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Baoquan He <bhe@redhat.com> Cc: David Gow <davidgow@google.com> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Huacai Chen <chenhuacai@loongson.cn> Cc: Marco Elver <elver@google.com> Cc: Qing Zhang <zhangqing@loongson.cn> Cc: Sabyrzhan Tasbolatov <snovitoll@gmail.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-03-09kasan: fix a missing header include of static_keys.hJoey Gouly
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 <pcc@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Acked-by: Andrey Konovalov <andreyknvl@gmail.com> Signed-off-by: Joey Gouly <joey.gouly@arm.com> Link: https://lore.kernel.org/r/20220301154518.19456-1-joey.gouly@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2022-02-22kasan: split kasan_*enabled() functions into a separate headerPeter Collingbourne
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 <pcc@google.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Link: https://lore.kernel.org/r/20220219012945.894950-1-pcc@google.com Signed-off-by: Will Deacon <will@kernel.org>