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-rw-r--r--arch/arm64/include/asm/memory.h1
-rw-r--r--arch/arm64/include/asm/mte-kasan.h5
-rw-r--r--arch/arm64/include/asm/mte.h6
-rw-r--r--arch/arm64/include/asm/sysreg.h16
-rw-r--r--arch/arm64/kernel/entry.S5
-rw-r--r--arch/arm64/kernel/mte.c31
-rw-r--r--arch/arm64/kernel/suspend.c1
-rw-r--r--arch/arm64/mm/proc.S3
-rw-r--r--include/linux/kasan-tags.h15
-rw-r--r--mm/kasan/hw_tags.c2
-rw-r--r--mm/kasan/kasan.h15
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()
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-29 05:40:56 +0300