diff options
| -rw-r--r-- | arch/arm64/include/asm/memory.h | 1 | ||||
| -rw-r--r-- | arch/arm64/include/asm/mte-kasan.h | 5 | ||||
| -rw-r--r-- | arch/arm64/include/asm/mte.h | 6 | ||||
| -rw-r--r-- | arch/arm64/include/asm/sysreg.h | 16 | ||||
| -rw-r--r-- | arch/arm64/kernel/entry.S | 5 | ||||
| -rw-r--r-- | arch/arm64/kernel/mte.c | 31 | ||||
| -rw-r--r-- | arch/arm64/kernel/suspend.c | 1 | ||||
| -rw-r--r-- | arch/arm64/mm/proc.S | 3 | ||||
| -rw-r--r-- | include/linux/kasan-tags.h | 15 | ||||
| -rw-r--r-- | mm/kasan/hw_tags.c | 2 | ||||
| -rw-r--r-- | mm/kasan/kasan.h | 15 |
11 files changed, 35 insertions, 65 deletions
diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index 824a3655dd93..7f4e6a923aa6 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -245,7 +245,6 @@ static inline const void *__tag_set(const void *addr, u8 tag) #define arch_enable_tagging_async() mte_enable_kernel_async() #define arch_set_tagging_report_once(state) mte_set_report_once(state) #define arch_force_async_tag_fault() mte_check_tfsr_exit() -#define arch_init_tags(max_tag) mte_init_tags(max_tag) #define arch_get_random_tag() mte_get_random_tag() #define arch_get_mem_tag(addr) mte_get_mem_tag(addr) #define arch_set_mem_tag_range(addr, size, tag, init) \ diff --git a/arch/arm64/include/asm/mte-kasan.h b/arch/arm64/include/asm/mte-kasan.h index d952352bd008..82fa4ac4ad4e 100644 --- a/arch/arm64/include/asm/mte-kasan.h +++ b/arch/arm64/include/asm/mte-kasan.h @@ -130,7 +130,6 @@ static inline void mte_set_mem_tag_range(void *addr, size_t size, u8 tag, void mte_enable_kernel_sync(void); void mte_enable_kernel_async(void); -void mte_init_tags(u64 max_tag); void mte_set_report_once(bool state); bool mte_report_once(void); @@ -165,10 +164,6 @@ static inline void mte_enable_kernel_async(void) { } -static inline void mte_init_tags(u64 max_tag) -{ -} - static inline void mte_set_report_once(bool state) { } diff --git a/arch/arm64/include/asm/mte.h b/arch/arm64/include/asm/mte.h index 58c7f80f5596..3f93b9e0b339 100644 --- a/arch/arm64/include/asm/mte.h +++ b/arch/arm64/include/asm/mte.h @@ -16,8 +16,6 @@ #include <asm/pgtable-types.h> -extern u64 gcr_kernel_excl; - void mte_clear_page_tags(void *addr); unsigned long mte_copy_tags_from_user(void *to, const void __user *from, unsigned long n); @@ -43,7 +41,6 @@ void mte_copy_page_tags(void *kto, const void *kfrom); void mte_thread_init_user(void); void mte_thread_switch(struct task_struct *next); void mte_suspend_enter(void); -void mte_suspend_exit(void); long set_mte_ctrl(struct task_struct *task, unsigned long arg); long get_mte_ctrl(struct task_struct *task); int mte_ptrace_copy_tags(struct task_struct *child, long request, @@ -72,9 +69,6 @@ static inline void mte_thread_switch(struct task_struct *next) static inline void mte_suspend_enter(void) { } -static inline void mte_suspend_exit(void) -{ -} static inline long set_mte_ctrl(struct task_struct *task, unsigned long arg) { return 0; diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index 7b9c3acba684..f6687f6f536b 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -11,6 +11,7 @@ #include <linux/bits.h> #include <linux/stringify.h> +#include <linux/kasan-tags.h> /* * ARMv8 ARM reserves the following encoding for system registers: @@ -1067,6 +1068,21 @@ #define SYS_GCR_EL1_RRND (BIT(16)) #define SYS_GCR_EL1_EXCL_MASK 0xffffUL +#ifdef CONFIG_KASAN_HW_TAGS +/* + * KASAN always uses a whole byte for its tags. With CONFIG_KASAN_HW_TAGS it + * only uses tags in the range 0xF0-0xFF, which we map to MTE tags 0x0-0xF. + */ +#define __MTE_TAG_MIN (KASAN_TAG_MIN & 0xf) +#define __MTE_TAG_MAX (KASAN_TAG_MAX & 0xf) +#define __MTE_TAG_INCL GENMASK(__MTE_TAG_MAX, __MTE_TAG_MIN) +#define KERNEL_GCR_EL1_EXCL (SYS_GCR_EL1_EXCL_MASK & ~__MTE_TAG_INCL) +#else +#define KERNEL_GCR_EL1_EXCL SYS_GCR_EL1_EXCL_MASK +#endif + +#define KERNEL_GCR_EL1 (SYS_GCR_EL1_RRND | KERNEL_GCR_EL1_EXCL) + /* RGSR_EL1 Definitions */ #define SYS_RGSR_EL1_TAG_MASK 0xfUL #define SYS_RGSR_EL1_SEED_SHIFT 8 diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 468fae024bec..923ee2ac85fd 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -181,9 +181,8 @@ alternative_else_nop_endif alternative_if_not ARM64_MTE b 1f alternative_else_nop_endif - ldr_l \tmp, gcr_kernel_excl - - mte_set_gcr \tmp, \tmp2 + mov \tmp, KERNEL_GCR_EL1 + msr_s SYS_GCR_EL1, \tmp 1: #endif .endm diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c index 20a40e5a14fa..b538ff27a912 100644 --- a/arch/arm64/kernel/mte.c +++ b/arch/arm64/kernel/mte.c @@ -23,8 +23,6 @@ #include <asm/ptrace.h> #include <asm/sysreg.h> -u64 gcr_kernel_excl __ro_after_init; - static bool report_fault_once = true; static DEFINE_PER_CPU_READ_MOSTLY(u64, mte_tcf_preferred); @@ -104,26 +102,6 @@ int memcmp_pages(struct page *page1, struct page *page2) return ret; } -void mte_init_tags(u64 max_tag) -{ - static bool gcr_kernel_excl_initialized; - - if (!gcr_kernel_excl_initialized) { - /* - * The format of the tags in KASAN is 0xFF and in MTE is 0xF. - * This conversion extracts an MTE tag from a KASAN tag. - */ - u64 incl = GENMASK(FIELD_GET(MTE_TAG_MASK >> MTE_TAG_SHIFT, - max_tag), 0); - - gcr_kernel_excl = ~incl & SYS_GCR_EL1_EXCL_MASK; - gcr_kernel_excl_initialized = true; - } - - /* Enable the kernel exclude mask for random tags generation. */ - write_sysreg_s(SYS_GCR_EL1_RRND | gcr_kernel_excl, SYS_GCR_EL1); -} - static inline void __mte_enable_kernel(const char *mode, unsigned long tcf) { /* Enable MTE Sync Mode for EL1. */ @@ -262,15 +240,6 @@ void mte_suspend_enter(void) mte_check_tfsr_el1(); } -void mte_suspend_exit(void) -{ - if (!system_supports_mte()) - return; - - sysreg_clear_set_s(SYS_GCR_EL1, SYS_GCR_EL1_EXCL_MASK, gcr_kernel_excl); - isb(); -} - long set_mte_ctrl(struct task_struct *task, unsigned long arg) { u64 mte_ctrl = (~((arg & PR_MTE_TAG_MASK) >> PR_MTE_TAG_SHIFT) & diff --git a/arch/arm64/kernel/suspend.c b/arch/arm64/kernel/suspend.c index 938ce6fbee8a..19ee7c33769d 100644 --- a/arch/arm64/kernel/suspend.c +++ b/arch/arm64/kernel/suspend.c @@ -76,7 +76,6 @@ void notrace __cpu_suspend_exit(void) spectre_v4_enable_mitigation(NULL); /* Restore additional feature-specific configuration */ - mte_suspend_exit(); ptrauth_suspend_exit(); } diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index 35936c5ae1ce..d35c90d2e47a 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -437,8 +437,7 @@ SYM_FUNC_START(__cpu_setup) mov x10, #MAIR_ATTR_NORMAL_TAGGED bfi mair, x10, #(8 * MT_NORMAL_TAGGED), #8 - /* initialize GCR_EL1: all non-zero tags excluded by default */ - mov x10, #(SYS_GCR_EL1_RRND | SYS_GCR_EL1_EXCL_MASK) + mov x10, #KERNEL_GCR_EL1 msr_s SYS_GCR_EL1, x10 /* diff --git a/include/linux/kasan-tags.h b/include/linux/kasan-tags.h new file mode 100644 index 000000000000..4f85f562512c --- /dev/null +++ b/include/linux/kasan-tags.h @@ -0,0 +1,15 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_KASAN_TAGS_H +#define _LINUX_KASAN_TAGS_H + +#define KASAN_TAG_KERNEL 0xFF /* native kernel pointers tag */ +#define KASAN_TAG_INVALID 0xFE /* inaccessible memory tag */ +#define KASAN_TAG_MAX 0xFD /* maximum value for random tags */ + +#ifdef CONFIG_KASAN_HW_TAGS +#define KASAN_TAG_MIN 0xF0 /* minimum value for random tags */ +#else +#define KASAN_TAG_MIN 0x00 /* minimum value for random tags */ +#endif + +#endif /* LINUX_KASAN_TAGS_H */ diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c index 4ea8c368b5b8..2c6c6c6ddfa2 100644 --- a/mm/kasan/hw_tags.c +++ b/mm/kasan/hw_tags.c @@ -142,8 +142,6 @@ void kasan_init_hw_tags_cpu(void) if (kasan_arg == KASAN_ARG_OFF) return; - hw_init_tags(KASAN_TAG_MAX); - /* * Enable async mode only when explicitly requested through * the command line. diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index d739cdd1621a..28a16b80bbef 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -3,6 +3,7 @@ #define __MM_KASAN_KASAN_H #include <linux/kasan.h> +#include <linux/kasan-tags.h> #include <linux/kfence.h> #include <linux/stackdepot.h> @@ -51,16 +52,6 @@ extern bool kasan_flag_async __ro_after_init; #define KASAN_MEMORY_PER_SHADOW_PAGE (KASAN_GRANULE_SIZE << PAGE_SHIFT) -#define KASAN_TAG_KERNEL 0xFF /* native kernel pointers tag */ -#define KASAN_TAG_INVALID 0xFE /* inaccessible memory tag */ -#define KASAN_TAG_MAX 0xFD /* maximum value for random tags */ - -#ifdef CONFIG_KASAN_HW_TAGS -#define KASAN_TAG_MIN 0xF0 /* minimum value for random tags */ -#else -#define KASAN_TAG_MIN 0x00 /* minimum value for random tags */ -#endif - #ifdef CONFIG_KASAN_GENERIC #define KASAN_FREE_PAGE 0xFF /* page was freed */ #define KASAN_PAGE_REDZONE 0xFE /* redzone for kmalloc_large allocations */ @@ -299,9 +290,6 @@ static inline const void *arch_kasan_set_tag(const void *addr, u8 tag) #ifndef arch_enable_tagging_async #define arch_enable_tagging_async() #endif -#ifndef arch_init_tags -#define arch_init_tags(max_tag) -#endif #ifndef arch_set_tagging_report_once #define arch_set_tagging_report_once(state) #endif @@ -320,7 +308,6 @@ static inline const void *arch_kasan_set_tag(const void *addr, u8 tag) #define hw_enable_tagging_sync() arch_enable_tagging_sync() #define hw_enable_tagging_async() arch_enable_tagging_async() -#define hw_init_tags(max_tag) arch_init_tags(max_tag) #define hw_set_tagging_report_once(state) arch_set_tagging_report_once(state) #define hw_force_async_tag_fault() arch_force_async_tag_fault() #define hw_get_random_tag() arch_get_random_tag() |