diff options
Diffstat (limited to 'arch/x86/include/asm/uaccess.h')
| -rw-r--r-- | arch/x86/include/asm/uaccess.h | 318 |
1 files changed, 171 insertions, 147 deletions
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index ecefaffd15d4..477c503f2753 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -96,25 +96,14 @@ static inline bool pagefault_disabled(void); likely(!__range_not_ok(addr, size, user_addr_max())); \ }) -/* - * These are the main single-value transfer routines. They automatically - * use the right size if we just have the right pointer type. - * - * This gets kind of ugly. We want to return _two_ values in "get_user()" - * and yet we don't want to do any pointers, because that is too much - * of a performance impact. Thus we have a few rather ugly macros here, - * and hide all the ugliness from the user. - * - * The "__xxx" versions of the user access functions are versions that - * do not verify the address space, that must have been done previously - * with a separate "access_ok()" call (this is used when we do multiple - * accesses to the same area of user memory). - */ - extern int __get_user_1(void); extern int __get_user_2(void); extern int __get_user_4(void); extern int __get_user_8(void); +extern int __get_user_nocheck_1(void); +extern int __get_user_nocheck_2(void); +extern int __get_user_nocheck_4(void); +extern int __get_user_nocheck_8(void); extern int __get_user_bad(void); #define __uaccess_begin() stac() @@ -138,25 +127,12 @@ extern int __get_user_bad(void); #define __typefits(x,type,not) \ __builtin_choose_expr(sizeof(x)<=sizeof(type),(unsigned type)0,not) -/** - * get_user - Get a simple variable from user space. - * @x: Variable to store result. - * @ptr: Source address, in user space. - * - * Context: User context only. This function may sleep if pagefaults are - * enabled. - * - * This macro copies a single simple variable from user space to kernel - * space. It supports simple types like char and int, but not larger - * data types like structures or arrays. - * - * @ptr must have pointer-to-simple-variable type, and the result of - * dereferencing @ptr must be assignable to @x without a cast. - * - * Return: zero on success, or -EFAULT on error. - * On error, the variable @x is set to zero. - */ /* + * This is used for both get_user() and __get_user() to expand to + * the proper special function call that has odd calling conventions + * due to returning both a value and an error, and that depends on + * the size of the pointer passed in. + * * Careful: we have to cast the result to the type of the pointer * for sign reasons. * @@ -169,13 +145,12 @@ extern int __get_user_bad(void); * Clang/LLVM cares about the size of the register, but still wants * the base register for something that ends up being a pair. */ -#define get_user(x, ptr) \ +#define do_get_user_call(fn,x,ptr) \ ({ \ int __ret_gu; \ register __inttype(*(ptr)) __val_gu asm("%"_ASM_DX); \ __chk_user_ptr(ptr); \ - might_fault(); \ - asm volatile("call __get_user_%P4" \ + asm volatile("call __" #fn "_%P4" \ : "=a" (__ret_gu), "=r" (__val_gu), \ ASM_CALL_CONSTRAINT \ : "0" (ptr), "i" (sizeof(*(ptr)))); \ @@ -183,10 +158,48 @@ extern int __get_user_bad(void); __builtin_expect(__ret_gu, 0); \ }) -#define __put_user_x(size, x, ptr, __ret_pu) \ - asm volatile("call __put_user_" #size : "=a" (__ret_pu) \ - : "0" ((typeof(*(ptr)))(x)), "c" (ptr) : "ebx") +/** + * get_user - Get a simple variable from user space. + * @x: Variable to store result. + * @ptr: Source address, in user space. + * + * Context: User context only. This function may sleep if pagefaults are + * enabled. + * + * This macro copies a single simple variable from user space to kernel + * space. It supports simple types like char and int, but not larger + * data types like structures or arrays. + * + * @ptr must have pointer-to-simple-variable type, and the result of + * dereferencing @ptr must be assignable to @x without a cast. + * + * Return: zero on success, or -EFAULT on error. + * On error, the variable @x is set to zero. + */ +#define get_user(x,ptr) ({ might_fault(); do_get_user_call(get_user,x,ptr); }) +/** + * __get_user - Get a simple variable from user space, with less checking. + * @x: Variable to store result. + * @ptr: Source address, in user space. + * + * Context: User context only. This function may sleep if pagefaults are + * enabled. + * + * This macro copies a single simple variable from user space to kernel + * space. It supports simple types like char and int, but not larger + * data types like structures or arrays. + * + * @ptr must have pointer-to-simple-variable type, and the result of + * dereferencing @ptr must be assignable to @x without a cast. + * + * Caller must check the pointer with access_ok() before calling this + * function. + * + * Return: zero on success, or -EFAULT on error. + * On error, the variable @x is set to zero. + */ +#define __get_user(x,ptr) do_get_user_call(get_user_nocheck,x,ptr) #ifdef CONFIG_X86_32 @@ -199,25 +212,41 @@ extern int __get_user_bad(void); : : "A" (x), "r" (addr) \ : : label) -#define __put_user_x8(x, ptr, __ret_pu) \ - asm volatile("call __put_user_8" : "=a" (__ret_pu) \ - : "A" ((typeof(*(ptr)))(x)), "c" (ptr) : "ebx") #else #define __put_user_goto_u64(x, ptr, label) \ __put_user_goto(x, ptr, "q", "er", label) -#define __put_user_x8(x, ptr, __ret_pu) __put_user_x(8, x, ptr, __ret_pu) #endif extern void __put_user_bad(void); /* * Strange magic calling convention: pointer in %ecx, - * value in %eax(:%edx), return value in %eax. clobbers %rbx + * value in %eax(:%edx), return value in %ecx. clobbers %rbx */ extern void __put_user_1(void); extern void __put_user_2(void); extern void __put_user_4(void); extern void __put_user_8(void); +extern void __put_user_nocheck_1(void); +extern void __put_user_nocheck_2(void); +extern void __put_user_nocheck_4(void); +extern void __put_user_nocheck_8(void); + +#define do_put_user_call(fn,x,ptr) \ +({ \ + int __ret_pu; \ + register __typeof__(*(ptr)) __val_pu asm("%"_ASM_AX); \ + __chk_user_ptr(ptr); \ + __val_pu = (x); \ + asm volatile("call __" #fn "_%P[size]" \ + : "=c" (__ret_pu), \ + ASM_CALL_CONSTRAINT \ + : "0" (ptr), \ + "r" (__val_pu), \ + [size] "i" (sizeof(*(ptr))) \ + :"ebx"); \ + __builtin_expect(__ret_pu, 0); \ +}) /** * put_user - Write a simple value into user space. @@ -236,32 +265,29 @@ extern void __put_user_8(void); * * Return: zero on success, or -EFAULT on error. */ -#define put_user(x, ptr) \ -({ \ - int __ret_pu; \ - __typeof__(*(ptr)) __pu_val; \ - __chk_user_ptr(ptr); \ - might_fault(); \ - __pu_val = x; \ - switch (sizeof(*(ptr))) { \ - case 1: \ - __put_user_x(1, __pu_val, ptr, __ret_pu); \ - break; \ - case 2: \ - __put_user_x(2, __pu_val, ptr, __ret_pu); \ - break; \ - case 4: \ - __put_user_x(4, __pu_val, ptr, __ret_pu); \ - break; \ - case 8: \ - __put_user_x8(__pu_val, ptr, __ret_pu); \ - break; \ - default: \ - __put_user_x(X, __pu_val, ptr, __ret_pu); \ - break; \ - } \ - __builtin_expect(__ret_pu, 0); \ -}) +#define put_user(x, ptr) ({ might_fault(); do_put_user_call(put_user,x,ptr); }) + +/** + * __put_user - Write a simple value into user space, with less checking. + * @x: Value to copy to user space. + * @ptr: Destination address, in user space. + * + * Context: User context only. This function may sleep if pagefaults are + * enabled. + * + * This macro copies a single simple value from kernel space to user + * space. It supports simple types like char and int, but not larger + * data types like structures or arrays. + * + * @ptr must have pointer-to-simple-variable type, and @x must be assignable + * to the result of dereferencing @ptr. + * + * Caller must check the pointer with access_ok() before calling this + * function. + * + * Return: zero on success, or -EFAULT on error. + */ +#define __put_user(x, ptr) do_put_user_call(put_user_nocheck,x,ptr) #define __put_user_size(x, ptr, size, label) \ do { \ @@ -284,6 +310,55 @@ do { \ } \ } while (0) +#ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT + +#ifdef CONFIG_X86_32 +#define __get_user_asm_u64(x, ptr, label) do { \ + unsigned int __gu_low, __gu_high; \ + const unsigned int __user *__gu_ptr; \ + __gu_ptr = (const void __user *)(ptr); \ + __get_user_asm(__gu_low, ptr, "l", "=r", label); \ + __get_user_asm(__gu_high, ptr+1, "l", "=r", label); \ + (x) = ((unsigned long long)__gu_high << 32) | __gu_low; \ +} while (0) +#else +#define __get_user_asm_u64(x, ptr, label) \ + __get_user_asm(x, ptr, "q", "=r", label) +#endif + +#define __get_user_size(x, ptr, size, label) \ +do { \ + __chk_user_ptr(ptr); \ + switch (size) { \ + unsigned char x_u8__; \ + case 1: \ + __get_user_asm(x_u8__, ptr, "b", "=q", label); \ + (x) = x_u8__; \ + break; \ + case 2: \ + __get_user_asm(x, ptr, "w", "=r", label); \ + break; \ + case 4: \ + __get_user_asm(x, ptr, "l", "=r", label); \ + break; \ + case 8: \ + __get_user_asm_u64(x, ptr, label); \ + break; \ + default: \ + (x) = __get_user_bad(); \ + } \ +} while (0) + +#define __get_user_asm(x, addr, itype, ltype, label) \ + asm_volatile_goto("\n" \ + "1: mov"itype" %[umem],%[output]\n" \ + _ASM_EXTABLE_UA(1b, %l2) \ + : [output] ltype(x) \ + : [umem] "m" (__m(addr)) \ + : : label) + +#else // !CONFIG_CC_HAS_ASM_GOTO_OUTPUT + #ifdef CONFIG_X86_32 #define __get_user_asm_u64(x, ptr, retval) \ ({ \ @@ -343,7 +418,7 @@ do { \ "2:\n" \ ".section .fixup,\"ax\"\n" \ "3: mov %[efault],%[errout]\n" \ - " xor"itype" %[output],%[output]\n" \ + " xorl %k[output],%k[output]\n" \ " jmp 2b\n" \ ".previous\n" \ _ASM_EXTABLE_UA(1b, 3b) \ @@ -352,33 +427,7 @@ do { \ : [umem] "m" (__m(addr)), \ [efault] "i" (-EFAULT), "0" (err)) -#define __put_user_nocheck(x, ptr, size) \ -({ \ - __label__ __pu_label; \ - int __pu_err = -EFAULT; \ - __typeof__(*(ptr)) __pu_val = (x); \ - __typeof__(ptr) __pu_ptr = (ptr); \ - __typeof__(size) __pu_size = (size); \ - __uaccess_begin(); \ - __put_user_size(__pu_val, __pu_ptr, __pu_size, __pu_label); \ - __pu_err = 0; \ -__pu_label: \ - __uaccess_end(); \ - __builtin_expect(__pu_err, 0); \ -}) - -#define __get_user_nocheck(x, ptr, size) \ -({ \ - int __gu_err; \ - __inttype(*(ptr)) __gu_val; \ - __typeof__(ptr) __gu_ptr = (ptr); \ - __typeof__(size) __gu_size = (size); \ - __uaccess_begin_nospec(); \ - __get_user_size(__gu_val, __gu_ptr, __gu_size, __gu_err); \ - __uaccess_end(); \ - (x) = (__force __typeof__(*(ptr)))__gu_val; \ - __builtin_expect(__gu_err, 0); \ -}) +#endif // CONFIG_CC_ASM_GOTO_OUTPUT /* FIXME: this hack is definitely wrong -AK */ struct __large_struct { unsigned long buf[100]; }; @@ -396,55 +445,6 @@ struct __large_struct { unsigned long buf[100]; }; : : ltype(x), "m" (__m(addr)) \ : : label) -/** - * __get_user - Get a simple variable from user space, with less checking. - * @x: Variable to store result. - * @ptr: Source address, in user space. - * - * Context: User context only. This function may sleep if pagefaults are - * enabled. - * - * This macro copies a single simple variable from user space to kernel - * space. It supports simple types like char and int, but not larger - * data types like structures or arrays. - * - * @ptr must have pointer-to-simple-variable type, and the result of - * dereferencing @ptr must be assignable to @x without a cast. - * - * Caller must check the pointer with access_ok() before calling this - * function. - * - * Return: zero on success, or -EFAULT on error. - * On error, the variable @x is set to zero. - */ - -#define __get_user(x, ptr) \ - __get_user_nocheck((x), (ptr), sizeof(*(ptr))) - -/** - * __put_user - Write a simple value into user space, with less checking. - * @x: Value to copy to user space. - * @ptr: Destination address, in user space. - * - * Context: User context only. This function may sleep if pagefaults are - * enabled. - * - * This macro copies a single simple value from kernel space to user - * space. It supports simple types like char and int, but not larger - * data types like structures or arrays. - * - * @ptr must have pointer-to-simple-variable type, and @x must be assignable - * to the result of dereferencing @ptr. - * - * Caller must check the pointer with access_ok() before calling this - * function. - * - * Return: zero on success, or -EFAULT on error. - */ - -#define __put_user(x, ptr) \ - __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) - extern unsigned long copy_from_user_nmi(void *to, const void __user *from, unsigned long n); extern __must_check long @@ -455,6 +455,15 @@ extern __must_check long strnlen_user(const char __user *str, long n); unsigned long __must_check clear_user(void __user *mem, unsigned long len); unsigned long __must_check __clear_user(void __user *mem, unsigned long len); +#ifdef CONFIG_ARCH_HAS_COPY_MC +unsigned long __must_check +copy_mc_to_kernel(void *to, const void *from, unsigned len); +#define copy_mc_to_kernel copy_mc_to_kernel + +unsigned long __must_check +copy_mc_to_user(void *to, const void *from, unsigned len); +#endif + /* * movsl can be slow when source and dest are not both 8-byte aligned */ @@ -494,6 +503,14 @@ static __must_check __always_inline bool user_access_begin(const void __user *pt #define unsafe_put_user(x, ptr, label) \ __put_user_size((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)), label) +#ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT +#define unsafe_get_user(x, ptr, err_label) \ +do { \ + __inttype(*(ptr)) __gu_val; \ + __get_user_size(__gu_val, (ptr), sizeof(*(ptr)), err_label); \ + (x) = (__force __typeof__(*(ptr)))__gu_val; \ +} while (0) +#else // !CONFIG_CC_HAS_ASM_GOTO_OUTPUT #define unsafe_get_user(x, ptr, err_label) \ do { \ int __gu_err; \ @@ -502,6 +519,7 @@ do { \ (x) = (__force __typeof__(*(ptr)))__gu_val; \ if (unlikely(__gu_err)) goto err_label; \ } while (0) +#endif // CONFIG_CC_HAS_ASM_GOTO_OUTPUT /* * We want the unsafe accessors to always be inlined and use @@ -528,6 +546,11 @@ do { \ #define HAVE_GET_KERNEL_NOFAULT +#ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT +#define __get_kernel_nofault(dst, src, type, err_label) \ + __get_user_size(*((type *)(dst)), (__force type __user *)(src), \ + sizeof(type), err_label) +#else // !CONFIG_CC_HAS_ASM_GOTO_OUTPUT #define __get_kernel_nofault(dst, src, type, err_label) \ do { \ int __kr_err; \ @@ -537,6 +560,7 @@ do { \ if (unlikely(__kr_err)) \ goto err_label; \ } while (0) +#endif // CONFIG_CC_HAS_ASM_GOTO_OUTPUT #define __put_kernel_nofault(dst, src, type, err_label) \ __put_user_size(*((type *)(src)), (__force type __user *)(dst), \ |