Merge tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel...

[linux-block.git] / arch / arm64 / include / asm / uaccess.h

diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index 8209e6a869894d06bd663390e006c10ea4128d8b..05f4fc265428457b8316859f7bab81622aacc994 100644 (file)
--- 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;                                         \