mirror of
https://github.com/torvalds/linux.git
synced 2025-12-07 20:06:24 +00:00
1e338f4d99
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>
73 lines
2.0 KiB
C
73 lines
2.0 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef __ASM_KASAN_H
|
|
#define __ASM_KASAN_H
|
|
|
|
#if defined(CONFIG_KASAN) && !defined(CONFIG_CC_HAS_KASAN_MEMINTRINSIC_PREFIX)
|
|
#define _GLOBAL_KASAN(fn) _GLOBAL(__##fn)
|
|
#define _GLOBAL_TOC_KASAN(fn) _GLOBAL_TOC(__##fn)
|
|
#define EXPORT_SYMBOL_KASAN(fn) EXPORT_SYMBOL(__##fn)
|
|
#else
|
|
#define _GLOBAL_KASAN(fn) _GLOBAL(fn)
|
|
#define _GLOBAL_TOC_KASAN(fn) _GLOBAL_TOC(fn)
|
|
#define EXPORT_SYMBOL_KASAN(fn)
|
|
#endif
|
|
|
|
#ifndef __ASSEMBLY__
|
|
|
|
#include <asm/page.h>
|
|
#include <linux/sizes.h>
|
|
|
|
#define KASAN_SHADOW_SCALE_SHIFT 3
|
|
|
|
#if defined(CONFIG_EXECMEM) && defined(CONFIG_PPC32)
|
|
#define KASAN_KERN_START ALIGN_DOWN(PAGE_OFFSET - SZ_256M, SZ_256M)
|
|
#else
|
|
#define KASAN_KERN_START PAGE_OFFSET
|
|
#endif
|
|
|
|
#define KASAN_SHADOW_START (KASAN_SHADOW_OFFSET + \
|
|
(KASAN_KERN_START >> KASAN_SHADOW_SCALE_SHIFT))
|
|
|
|
#define KASAN_SHADOW_OFFSET ASM_CONST(CONFIG_KASAN_SHADOW_OFFSET)
|
|
|
|
#ifdef CONFIG_PPC32
|
|
#define KASAN_SHADOW_END (-(-KASAN_SHADOW_START >> KASAN_SHADOW_SCALE_SHIFT))
|
|
#elif defined(CONFIG_PPC_BOOK3S_64)
|
|
/*
|
|
* The shadow ends before the highest accessible address
|
|
* because we don't need a shadow for the shadow. Instead:
|
|
* c00e000000000000 << 3 + a80e000000000000 = c00fc00000000000
|
|
*/
|
|
#define KASAN_SHADOW_END 0xc00fc00000000000UL
|
|
|
|
#else
|
|
|
|
/*
|
|
* The shadow ends before the highest accessible address
|
|
* because we don't need a shadow for the shadow.
|
|
* But it doesn't hurt to have a shadow for the shadow,
|
|
* keep shadow end aligned eases things.
|
|
*/
|
|
#define KASAN_SHADOW_END 0xc000200000000000UL
|
|
|
|
#endif
|
|
|
|
#ifdef CONFIG_KASAN
|
|
|
|
void kasan_early_init(void);
|
|
void kasan_mmu_init(void);
|
|
void kasan_init(void);
|
|
void kasan_late_init(void);
|
|
#else
|
|
static inline void kasan_init(void) { }
|
|
static inline void kasan_mmu_init(void) { }
|
|
static inline void kasan_late_init(void) { }
|
|
#endif
|
|
|
|
void kasan_update_early_region(unsigned long k_start, unsigned long k_end, pte_t pte);
|
|
int kasan_init_shadow_page_tables(unsigned long k_start, unsigned long k_end);
|
|
int kasan_init_region(void *start, size_t size);
|
|
|
|
#endif /* __ASSEMBLY */
|
|
#endif
|