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 5c7b2f9d5913759472a1cb79335ca7263c6a5b4d..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;
@@ -237,7 +191,7 @@ static inline void __user *__uaccess_mask_ptr(const void __user *ptr)
        "1:     " load "        " reg "1, [%2]\n"                       \
        "2:\n"                                                          \
        _ASM_EXTABLE_##type##ACCESS_ERR_ZERO(1b, 2b, %w0, %w1)          \
-       : "+r" (err), "=&r" (x)                                         \
+       : "+r" (err), "=r" (x)                                          \
        : "r" (addr))
 
 #define __raw_get_mem(ldr, x, ptr, err, type)                                  \
@@ -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;                                         \
@@ -327,7 +281,7 @@ do {                                                                        \
        "2:\n"                                                          \
        _ASM_EXTABLE_##type##ACCESS_ERR(1b, 2b, %w0)                    \
        : "+r" (err)                                                    \
-       : "r" (x), "r" (addr))
+       : "rZ" (x), "r" (addr))
 
 #define __raw_put_mem(str, x, ptr, err, type)                                  \
 do {                                                                           \
@@ -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;                                         \
@@ -449,8 +403,6 @@ extern long strncpy_from_user(char *dest, const char __user *src, long count);
 extern __must_check long strnlen_user(const char __user *str, long n);
 
 #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
-struct page;
-void memcpy_page_flushcache(char *to, struct page *page, size_t offset, size_t len);
 extern unsigned long __must_check __copy_user_flushcache(void *to, const void __user *from, unsigned long n);
 
 static inline int __copy_from_user_flushcache(void *dst, const void __user *src, unsigned size)