summaryrefslogtreecommitdiff
path: root/arch/arm64/include/asm/uaccess.h
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm64/include/asm/uaccess.h')
-rw-r--r--arch/arm64/include/asm/uaccess.h66
1 files changed, 10 insertions, 56 deletions
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index 8209e6a86989..05f4fc265428 100644
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h
@@ -136,55 +136,9 @@ static inline void __uaccess_enable_hw_pan(void)
CONFIG_ARM64_PAN));
}
-/*
- * The Tag Check Flag (TCF) mode for MTE is per EL, hence TCF0
- * affects EL0 and TCF affects EL1 irrespective of which TTBR is
- * used.
- * The kernel accesses TTBR0 usually with LDTR/STTR instructions
- * when UAO is available, so these would act as EL0 accesses using
- * TCF0.
- * However futex.h code uses exclusives which would be executed as
- * EL1, this can potentially cause a tag check fault even if the
- * user disables TCF0.
- *
- * To address the problem we set the PSTATE.TCO bit in uaccess_enable()
- * and reset it in uaccess_disable().
- *
- * The Tag check override (TCO) bit disables temporarily the tag checking
- * preventing the issue.
- */
-static inline void __uaccess_disable_tco(void)
-{
- asm volatile(ALTERNATIVE("nop", SET_PSTATE_TCO(0),
- ARM64_MTE, CONFIG_KASAN_HW_TAGS));
-}
-
-static inline void __uaccess_enable_tco(void)
-{
- asm volatile(ALTERNATIVE("nop", SET_PSTATE_TCO(1),
- ARM64_MTE, CONFIG_KASAN_HW_TAGS));
-}
-
-/*
- * These functions disable tag checking only if in MTE async mode
- * since the sync mode generates exceptions synchronously and the
- * nofault or load_unaligned_zeropad can handle them.
- */
-static inline void __uaccess_disable_tco_async(void)
-{
- if (system_uses_mte_async_or_asymm_mode())
- __uaccess_disable_tco();
-}
-
-static inline void __uaccess_enable_tco_async(void)
-{
- if (system_uses_mte_async_or_asymm_mode())
- __uaccess_enable_tco();
-}
-
static inline void uaccess_disable_privileged(void)
{
- __uaccess_disable_tco();
+ mte_disable_tco();
if (uaccess_ttbr0_disable())
return;
@@ -194,7 +148,7 @@ static inline void uaccess_disable_privileged(void)
static inline void uaccess_enable_privileged(void)
{
- __uaccess_enable_tco();
+ mte_enable_tco();
if (uaccess_ttbr0_enable())
return;
@@ -302,8 +256,8 @@ do { \
#define get_user __get_user
/*
- * We must not call into the scheduler between __uaccess_enable_tco_async() and
- * __uaccess_disable_tco_async(). As `dst` and `src` may contain blocking
+ * We must not call into the scheduler between __mte_enable_tco_async() and
+ * __mte_disable_tco_async(). As `dst` and `src` may contain blocking
* functions, we must evaluate these outside of the critical section.
*/
#define __get_kernel_nofault(dst, src, type, err_label) \
@@ -312,10 +266,10 @@ do { \
__typeof__(src) __gkn_src = (src); \
int __gkn_err = 0; \
\
- __uaccess_enable_tco_async(); \
+ __mte_enable_tco_async(); \
__raw_get_mem("ldr", *((type *)(__gkn_dst)), \
(__force type *)(__gkn_src), __gkn_err, K); \
- __uaccess_disable_tco_async(); \
+ __mte_disable_tco_async(); \
\
if (unlikely(__gkn_err)) \
goto err_label; \
@@ -388,8 +342,8 @@ do { \
#define put_user __put_user
/*
- * We must not call into the scheduler between __uaccess_enable_tco_async() and
- * __uaccess_disable_tco_async(). As `dst` and `src` may contain blocking
+ * We must not call into the scheduler between __mte_enable_tco_async() and
+ * __mte_disable_tco_async(). As `dst` and `src` may contain blocking
* functions, we must evaluate these outside of the critical section.
*/
#define __put_kernel_nofault(dst, src, type, err_label) \
@@ -398,10 +352,10 @@ do { \
__typeof__(src) __pkn_src = (src); \
int __pkn_err = 0; \
\
- __uaccess_enable_tco_async(); \
+ __mte_enable_tco_async(); \
__raw_put_mem("str", *((type *)(__pkn_src)), \
(__force type *)(__pkn_dst), __pkn_err, K); \
- __uaccess_disable_tco_async(); \
+ __mte_disable_tco_async(); \
\
if (unlikely(__pkn_err)) \
goto err_label; \