diff options
Diffstat (limited to 'arch/arm64/include/asm/uaccess.h')
| -rw-r--r-- | arch/arm64/include/asm/uaccess.h | 121 |
1 files changed, 98 insertions, 23 deletions
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index 14be5000c5a0..3e721f73bcaf 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -184,29 +184,40 @@ static inline void __user *__uaccess_mask_ptr(const void __user *ptr) * The "__xxx_error" versions set the third argument to -EFAULT if an error * occurs, and leave it unchanged on success. */ -#define __get_mem_asm(load, reg, x, addr, err, type) \ +#ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT +#define __get_mem_asm(load, reg, x, addr, label, type) \ + asm_goto_output( \ + "1: " load " " reg "0, [%1]\n" \ + _ASM_EXTABLE_##type##ACCESS_ERR(1b, %l2, %w0) \ + : "=r" (x) \ + : "r" (addr) : : label) +#else +#define __get_mem_asm(load, reg, x, addr, label, type) do { \ + int __gma_err = 0; \ asm volatile( \ "1: " load " " reg "1, [%2]\n" \ "2:\n" \ _ASM_EXTABLE_##type##ACCESS_ERR_ZERO(1b, 2b, %w0, %w1) \ - : "+r" (err), "=r" (x) \ - : "r" (addr)) + : "+r" (__gma_err), "=r" (x) \ + : "r" (addr)); \ + if (__gma_err) goto label; } while (0) +#endif -#define __raw_get_mem(ldr, x, ptr, err, type) \ +#define __raw_get_mem(ldr, x, ptr, label, type) \ do { \ unsigned long __gu_val; \ switch (sizeof(*(ptr))) { \ case 1: \ - __get_mem_asm(ldr "b", "%w", __gu_val, (ptr), (err), type); \ + __get_mem_asm(ldr "b", "%w", __gu_val, (ptr), label, type); \ break; \ case 2: \ - __get_mem_asm(ldr "h", "%w", __gu_val, (ptr), (err), type); \ + __get_mem_asm(ldr "h", "%w", __gu_val, (ptr), label, type); \ break; \ case 4: \ - __get_mem_asm(ldr, "%w", __gu_val, (ptr), (err), type); \ + __get_mem_asm(ldr, "%w", __gu_val, (ptr), label, type); \ break; \ case 8: \ - __get_mem_asm(ldr, "%x", __gu_val, (ptr), (err), type); \ + __get_mem_asm(ldr, "%x", __gu_val, (ptr), label, type); \ break; \ default: \ BUILD_BUG(); \ @@ -219,27 +230,34 @@ do { \ * uaccess_ttbr0_disable(). As `x` and `ptr` could contain blocking functions, * we must evaluate these outside of the critical section. */ -#define __raw_get_user(x, ptr, err) \ +#define __raw_get_user(x, ptr, label) \ do { \ __typeof__(*(ptr)) __user *__rgu_ptr = (ptr); \ __typeof__(x) __rgu_val; \ __chk_user_ptr(ptr); \ - \ - uaccess_ttbr0_enable(); \ - __raw_get_mem("ldtr", __rgu_val, __rgu_ptr, err, U); \ - uaccess_ttbr0_disable(); \ - \ - (x) = __rgu_val; \ + do { \ + __label__ __rgu_failed; \ + uaccess_ttbr0_enable(); \ + __raw_get_mem("ldtr", __rgu_val, __rgu_ptr, __rgu_failed, U); \ + uaccess_ttbr0_disable(); \ + (x) = __rgu_val; \ + break; \ + __rgu_failed: \ + uaccess_ttbr0_disable(); \ + goto label; \ + } while (0); \ } while (0) #define __get_user_error(x, ptr, err) \ do { \ + __label__ __gu_failed; \ __typeof__(*(ptr)) __user *__p = (ptr); \ might_fault(); \ if (access_ok(__p, sizeof(*__p))) { \ __p = uaccess_mask_ptr(__p); \ - __raw_get_user((x), __p, (err)); \ + __raw_get_user((x), __p, __gu_failed); \ } else { \ + __gu_failed: \ (x) = (__force __typeof__(x))0; (err) = -EFAULT; \ } \ } while (0) @@ -262,15 +280,18 @@ do { \ do { \ __typeof__(dst) __gkn_dst = (dst); \ __typeof__(src) __gkn_src = (src); \ - int __gkn_err = 0; \ - \ - __mte_enable_tco_async(); \ - __raw_get_mem("ldr", *((type *)(__gkn_dst)), \ - (__force type *)(__gkn_src), __gkn_err, K); \ - __mte_disable_tco_async(); \ + do { \ + __label__ __gkn_label; \ \ - if (unlikely(__gkn_err)) \ + __mte_enable_tco_async(); \ + __raw_get_mem("ldr", *((type *)(__gkn_dst)), \ + (__force type *)(__gkn_src), __gkn_label, K); \ + __mte_disable_tco_async(); \ + break; \ + __gkn_label: \ + __mte_disable_tco_async(); \ goto err_label; \ + } while (0); \ } while (0) #define __put_mem_asm(store, reg, x, addr, err, type) \ @@ -381,6 +402,60 @@ extern unsigned long __must_check __arch_copy_to_user(void __user *to, const voi __actu_ret; \ }) +static __must_check __always_inline bool user_access_begin(const void __user *ptr, size_t len) +{ + if (unlikely(!access_ok(ptr,len))) + return 0; + uaccess_ttbr0_enable(); + return 1; +} +#define user_access_begin(a,b) user_access_begin(a,b) +#define user_access_end() uaccess_ttbr0_disable() + +/* + * The arm64 inline asms should learn abut asm goto, and we should + * teach user_access_begin() about address masking. + */ +#define unsafe_put_user(x, ptr, label) do { \ + int __upu_err = 0; \ + __raw_put_mem("sttr", x, uaccess_mask_ptr(ptr), __upu_err, U); \ + if (__upu_err) goto label; \ +} while (0) + +#define unsafe_get_user(x, ptr, label) \ + __raw_get_mem("ldtr", x, uaccess_mask_ptr(ptr), label, U) + +/* + * KCSAN uses these to save and restore ttbr state. + * We do not support KCSAN with ARM64_SW_TTBR0_PAN, so + * they are no-ops. + */ +static inline unsigned long user_access_save(void) { return 0; } +static inline void user_access_restore(unsigned long enabled) { } + +/* + * We want the unsafe accessors to always be inlined and use + * the error labels - thus the macro games. + */ +#define unsafe_copy_loop(dst, src, len, type, label) \ + while (len >= sizeof(type)) { \ + unsafe_put_user(*(type *)(src),(type __user *)(dst),label); \ + dst += sizeof(type); \ + src += sizeof(type); \ + len -= sizeof(type); \ + } + +#define unsafe_copy_to_user(_dst,_src,_len,label) \ +do { \ + char __user *__ucu_dst = (_dst); \ + const char *__ucu_src = (_src); \ + size_t __ucu_len = (_len); \ + unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u64, label); \ + unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u32, label); \ + unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u16, label); \ + unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u8, label); \ +} while (0) + #define INLINE_COPY_TO_USER #define INLINE_COPY_FROM_USER |