PowerPC with radix MMU is the primary architecture that needs deferred KASAN initialization, as it requires complex shadow memory setup before KASAN can be safely enabled.
Select ARCH_DEFER_KASAN for PPC_RADIX_MMU to enable the static key mechanism for runtime KASAN control. Other PowerPC configurations (like book3e and 32-bit) can enable KASAN early and will use compile-time constants instead. Also call kasan_init_generic() which handles Generic KASAN initialization. For PowerPC radix MMU (which selects ARCH_DEFER_KASAN), this enables the static key. For other PowerPC variants, kasan_enable() is a no-op and kasan_enabled() returns IS_ENABLED(CONFIG_KASAN). Remove the PowerPC-specific static key and kasan_arch_is_ready() implementation in favor of the unified interface. This ensures that: - PowerPC radix gets the runtime control it needs - Other PowerPC variants get optimal compile-time behavior - No unnecessary overhead is added where not needed Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217049 Fixes: 55d77bae7342 ("kasan: fix Oops due to missing calls to kasan_arch_is_ready()") Signed-off-by: Sabyrzhan Tasbolatov <snovit...@gmail.com> --- Changes in v3: - Added CONFIG_ARCH_DEFER_KASAN selection for PPC_RADIX_MMU only - Kept ARCH_DISABLE_KASAN_INLINE selection since it's needed independently --- 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 +----- 5 files changed, 4 insertions(+), 19 deletions(-) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index c3e0cc83f12..e5a6aae6a77 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -123,6 +123,7 @@ config PPC # select ARCH_32BIT_OFF_T if PPC32 select ARCH_DISABLE_KASAN_INLINE if PPC_RADIX_MMU + select ARCH_DEFER_KASAN if PPC_RADIX_MMU select ARCH_DMA_DEFAULT_COHERENT if !NOT_COHERENT_CACHE select ARCH_ENABLE_MEMORY_HOTPLUG select ARCH_ENABLE_MEMORY_HOTREMOVE diff --git a/arch/powerpc/include/asm/kasan.h b/arch/powerpc/include/asm/kasan.h index b5bbb94c51f..957a57c1db5 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 03666d790a5..1d083597464 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 60c78aac0f6..0d3a73d6d4b 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 7d959544c07..dcafa641804 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) { } -- 2.34.1
