[PATCH v3 03/12] kasan/powerpc: select ARCH_DEFER_KASAN and call kasan_init_generic
From: Sabyrzhan Tasbolatov <hidden>
Date: 2025-07-17 14:27:52
Also in:
linux-mm, linux-riscv, linux-s390, linux-um, lkml, loongarch
Subsystem:
kasan, linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Andrey Ryabinin, Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
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 <redacted> --- 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