| #ifndef _ASM_X86_UACCESS_H |
| #define _ASM_X86_UACCESS_H |
| /* |
| * User space memory access functions |
| */ |
| #include <linux/errno.h> |
| #include <linux/compiler.h> |
| #include <linux/kasan-checks.h> |
| #include <linux/thread_info.h> |
| #include <linux/string.h> |
| #include <asm/asm.h> |
| #include <asm/page.h> |
| #include <asm/smap.h> |
| #include <asm/extable.h> |
| |
| #define VERIFY_READ 0 |
| #define VERIFY_WRITE 1 |
| |
| /* |
| * The fs value determines whether argument validity checking should be |
| * performed or not. If get_fs() == USER_DS, checking is performed, with |
| * get_fs() == KERNEL_DS, checking is bypassed. |
| * |
| * For historical reasons, these macros are grossly misnamed. |
| */ |
| |
| #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) |
| |
| #define KERNEL_DS MAKE_MM_SEG(-1UL) |
| #define USER_DS MAKE_MM_SEG(TASK_SIZE_MAX) |
| |
| #define get_ds() (KERNEL_DS) |
| #define get_fs() (current->thread.addr_limit) |
| #define set_fs(x) (current->thread.addr_limit = (x)) |
| |
| #define segment_eq(a, b) ((a).seg == (b).seg) |
| |
| #define user_addr_max() (current->thread.addr_limit.seg) |
| #define __addr_ok(addr) \ |
| ((unsigned long __force)(addr) < user_addr_max()) |
| |
| /* |
| * Test whether a block of memory is a valid user space address. |
| * Returns 0 if the range is valid, nonzero otherwise. |
| */ |
| static inline bool __chk_range_not_ok(unsigned long addr, unsigned long size, unsigned long limit) |
| { |
| /* |
| * If we have used "sizeof()" for the size, |
| * we know it won't overflow the limit (but |
| * it might overflow the 'addr', so it's |
| * important to subtract the size from the |
| * limit, not add it to the address). |
| */ |
| if (__builtin_constant_p(size)) |
| return unlikely(addr > limit - size); |
| |
| /* Arbitrary sizes? Be careful about overflow */ |
| addr += size; |
| if (unlikely(addr < size)) |
| return true; |
| return unlikely(addr > limit); |
| } |
| |
| #define __range_not_ok(addr, size, limit) \ |
| ({ \ |
| __chk_user_ptr(addr); \ |
| __chk_range_not_ok((unsigned long __force)(addr), size, limit); \ |
| }) |
| |
| /** |
| * access_ok: - Checks if a user space pointer is valid |
| * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that |
| * %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe |
| * to write to a block, it is always safe to read from it. |
| * @addr: User space pointer to start of block to check |
| * @size: Size of block to check |
| * |
| * Context: User context only. This function may sleep if pagefaults are |
| * enabled. |
| * |
| * Checks if a pointer to a block of memory in user space is valid. |
| * |
| * Returns true (nonzero) if the memory block may be valid, false (zero) |
| * if it is definitely invalid. |
| * |
| * Note that, depending on architecture, this function probably just |
| * checks that the pointer is in the user space range - after calling |
| * this function, memory access functions may still return -EFAULT. |
| */ |
| #define access_ok(type, addr, size) \ |
| 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_bad(void); |
| |
| #define __uaccess_begin() stac() |
| #define __uaccess_end() clac() |
| |
| /* |
| * This is a type: either unsigned long, if the argument fits into |
| * that type, or otherwise unsigned long long. |
| */ |
| #define __inttype(x) \ |
| __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL)) |
| |
| /** |
| * 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. |
| * |
| * Returns zero on success, or -EFAULT on error. |
| * On error, the variable @x is set to zero. |
| */ |
| /* |
| * Careful: we have to cast the result to the type of the pointer |
| * for sign reasons. |
| * |
| * The use of _ASM_DX as the register specifier is a bit of a |
| * simplification, as gcc only cares about it as the starting point |
| * and not size: for a 64-bit value it will use %ecx:%edx on 32 bits |
| * (%ecx being the next register in gcc's x86 register sequence), and |
| * %rdx on 64 bits. |
| * |
| * 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) \ |
| ({ \ |
| int __ret_gu; \ |
| register __inttype(*(ptr)) __val_gu asm("%"_ASM_DX); \ |
| register void *__sp asm(_ASM_SP); \ |
| __chk_user_ptr(ptr); \ |
| might_fault(); \ |
| asm volatile("call __get_user_%P4" \ |
| : "=a" (__ret_gu), "=r" (__val_gu), "+r" (__sp) \ |
| : "0" (ptr), "i" (sizeof(*(ptr)))); \ |
| (x) = (__force __typeof__(*(ptr))) __val_gu; \ |
| __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") |
| |
| |
| |
| #ifdef CONFIG_X86_32 |
| #define __put_user_asm_u64(x, addr, err, errret) \ |
| asm volatile("\n" \ |
| "1: movl %%eax,0(%2)\n" \ |
| "2: movl %%edx,4(%2)\n" \ |
| "3:" \ |
| ".section .fixup,\"ax\"\n" \ |
| "4: movl %3,%0\n" \ |
| " jmp 3b\n" \ |
| ".previous\n" \ |
| _ASM_EXTABLE(1b, 4b) \ |
| _ASM_EXTABLE(2b, 4b) \ |
| : "=r" (err) \ |
| : "A" (x), "r" (addr), "i" (errret), "0" (err)) |
| |
| #define __put_user_asm_ex_u64(x, addr) \ |
| asm volatile("\n" \ |
| "1: movl %%eax,0(%1)\n" \ |
| "2: movl %%edx,4(%1)\n" \ |
| "3:" \ |
| _ASM_EXTABLE_EX(1b, 2b) \ |
| _ASM_EXTABLE_EX(2b, 3b) \ |
| : : "A" (x), "r" (addr)) |
| |
| #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_asm_u64(x, ptr, retval, errret) \ |
| __put_user_asm(x, ptr, retval, "q", "", "er", errret) |
| #define __put_user_asm_ex_u64(x, addr) \ |
| __put_user_asm_ex(x, addr, "q", "", "er") |
| #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 |
| */ |
| extern void __put_user_1(void); |
| extern void __put_user_2(void); |
| extern void __put_user_4(void); |
| extern void __put_user_8(void); |
| |
| /** |
| * put_user: - Write a simple value into user space. |
| * @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. |
| * |
| * Returns 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_size(x, ptr, size, retval, errret) \ |
| do { \ |
| retval = 0; \ |
| __chk_user_ptr(ptr); \ |
| switch (size) { \ |
| case 1: \ |
| __put_user_asm(x, ptr, retval, "b", "b", "iq", errret); \ |
| break; \ |
| case 2: \ |
| __put_user_asm(x, ptr, retval, "w", "w", "ir", errret); \ |
| break; \ |
| case 4: \ |
| __put_user_asm(x, ptr, retval, "l", "k", "ir", errret); \ |
| break; \ |
| case 8: \ |
| __put_user_asm_u64((__typeof__(*ptr))(x), ptr, retval, \ |
| errret); \ |
| break; \ |
| default: \ |
| __put_user_bad(); \ |
| } \ |
| } while (0) |
| |
| /* |
| * This doesn't do __uaccess_begin/end - the exception handling |
| * around it must do that. |
| */ |
| #define __put_user_size_ex(x, ptr, size) \ |
| do { \ |
| __chk_user_ptr(ptr); \ |
| switch (size) { \ |
| case 1: \ |
| __put_user_asm_ex(x, ptr, "b", "b", "iq"); \ |
| break; \ |
| case 2: \ |
| __put_user_asm_ex(x, ptr, "w", "w", "ir"); \ |
| break; \ |
| case 4: \ |
| __put_user_asm_ex(x, ptr, "l", "k", "ir"); \ |
| break; \ |
| case 8: \ |
| __put_user_asm_ex_u64((__typeof__(*ptr))(x), ptr); \ |
| break; \ |
| default: \ |
| __put_user_bad(); \ |
| } \ |
| } while (0) |
| |
| #ifdef CONFIG_X86_32 |
| #define __get_user_asm_u64(x, ptr, retval, errret) \ |
| ({ \ |
| __typeof__(ptr) __ptr = (ptr); \ |
| asm volatile(ASM_STAC "\n" \ |
| "1: movl %2,%%eax\n" \ |
| "2: movl %3,%%edx\n" \ |
| "3: " ASM_CLAC "\n" \ |
| ".section .fixup,\"ax\"\n" \ |
| "4: mov %4,%0\n" \ |
| " xorl %%eax,%%eax\n" \ |
| " xorl %%edx,%%edx\n" \ |
| " jmp 3b\n" \ |
| ".previous\n" \ |
| _ASM_EXTABLE(1b, 4b) \ |
| _ASM_EXTABLE(2b, 4b) \ |
| : "=r" (retval), "=A"(x) \ |
| : "m" (__m(__ptr)), "m" __m(((u32 *)(__ptr)) + 1), \ |
| "i" (errret), "0" (retval)); \ |
| }) |
| |
| #define __get_user_asm_ex_u64(x, ptr) (x) = __get_user_bad() |
| #else |
| #define __get_user_asm_u64(x, ptr, retval, errret) \ |
| __get_user_asm(x, ptr, retval, "q", "", "=r", errret) |
| #define __get_user_asm_ex_u64(x, ptr) \ |
| __get_user_asm_ex(x, ptr, "q", "", "=r") |
| #endif |
| |
| #define __get_user_size(x, ptr, size, retval, errret) \ |
| do { \ |
| retval = 0; \ |
| __chk_user_ptr(ptr); \ |
| switch (size) { \ |
| case 1: \ |
| __get_user_asm(x, ptr, retval, "b", "b", "=q", errret); \ |
| break; \ |
| case 2: \ |
| __get_user_asm(x, ptr, retval, "w", "w", "=r", errret); \ |
| break; \ |
| case 4: \ |
| __get_user_asm(x, ptr, retval, "l", "k", "=r", errret); \ |
| break; \ |
| case 8: \ |
| __get_user_asm_u64(x, ptr, retval, errret); \ |
| break; \ |
| default: \ |
| (x) = __get_user_bad(); \ |
| } \ |
| } while (0) |
| |
| #define __get_user_asm(x, addr, err, itype, rtype, ltype, errret) \ |
| asm volatile("\n" \ |
| "1: mov"itype" %2,%"rtype"1\n" \ |
| "2:\n" \ |
| ".section .fixup,\"ax\"\n" \ |
| "3: mov %3,%0\n" \ |
| " xor"itype" %"rtype"1,%"rtype"1\n" \ |
| " jmp 2b\n" \ |
| ".previous\n" \ |
| _ASM_EXTABLE(1b, 3b) \ |
| : "=r" (err), ltype(x) \ |
| : "m" (__m(addr)), "i" (errret), "0" (err)) |
| |
| /* |
| * This doesn't do __uaccess_begin/end - the exception handling |
| * around it must do that. |
| */ |
| #define __get_user_size_ex(x, ptr, size) \ |
| do { \ |
| __chk_user_ptr(ptr); \ |
| switch (size) { \ |
| case 1: \ |
| __get_user_asm_ex(x, ptr, "b", "b", "=q"); \ |
| break; \ |
| case 2: \ |
| __get_user_asm_ex(x, ptr, "w", "w", "=r"); \ |
| break; \ |
| case 4: \ |
| __get_user_asm_ex(x, ptr, "l", "k", "=r"); \ |
| break; \ |
| case 8: \ |
| __get_user_asm_ex_u64(x, ptr); \ |
| break; \ |
| default: \ |
| (x) = __get_user_bad(); \ |
| } \ |
| } while (0) |
| |
| #define __get_user_asm_ex(x, addr, itype, rtype, ltype) \ |
| asm volatile("1: mov"itype" %1,%"rtype"0\n" \ |
| "2:\n" \ |
| ".section .fixup,\"ax\"\n" \ |
| "3:xor"itype" %"rtype"0,%"rtype"0\n" \ |
| " jmp 2b\n" \ |
| ".previous\n" \ |
| _ASM_EXTABLE_EX(1b, 3b) \ |
| : ltype(x) : "m" (__m(addr))) |
| |
| #define __put_user_nocheck(x, ptr, size) \ |
| ({ \ |
| int __pu_err; \ |
| __uaccess_begin(); \ |
| __put_user_size((x), (ptr), (size), __pu_err, -EFAULT); \ |
| __uaccess_end(); \ |
| __builtin_expect(__pu_err, 0); \ |
| }) |
| |
| #define __get_user_nocheck(x, ptr, size) \ |
| ({ \ |
| int __gu_err; \ |
| __inttype(*(ptr)) __gu_val; \ |
| __uaccess_begin(); \ |
| __get_user_size(__gu_val, (ptr), (size), __gu_err, -EFAULT); \ |
| __uaccess_end(); \ |
| (x) = (__force __typeof__(*(ptr)))__gu_val; \ |
| __builtin_expect(__gu_err, 0); \ |
| }) |
| |
| /* FIXME: this hack is definitely wrong -AK */ |
| struct __large_struct { unsigned long buf[100]; }; |
| #define __m(x) (*(struct __large_struct __user *)(x)) |
| |
| /* |
| * Tell gcc we read from memory instead of writing: this is because |
| * we do not write to any memory gcc knows about, so there are no |
| * aliasing issues. |
| */ |
| #define __put_user_asm(x, addr, err, itype, rtype, ltype, errret) \ |
| asm volatile("\n" \ |
| "1: mov"itype" %"rtype"1,%2\n" \ |
| "2:\n" \ |
| ".section .fixup,\"ax\"\n" \ |
| "3: mov %3,%0\n" \ |
| " jmp 2b\n" \ |
| ".previous\n" \ |
| _ASM_EXTABLE(1b, 3b) \ |
| : "=r"(err) \ |
| : ltype(x), "m" (__m(addr)), "i" (errret), "0" (err)) |
| |
| #define __put_user_asm_ex(x, addr, itype, rtype, ltype) \ |
| asm volatile("1: mov"itype" %"rtype"0,%1\n" \ |
| "2:\n" \ |
| _ASM_EXTABLE_EX(1b, 2b) \ |
| : : ltype(x), "m" (__m(addr))) |
| |
| /* |
| * uaccess_try and catch |
| */ |
| #define uaccess_try do { \ |
| current->thread.uaccess_err = 0; \ |
| __uaccess_begin(); \ |
| barrier(); |
| |
| #define uaccess_catch(err) \ |
| __uaccess_end(); \ |
| (err) |= (current->thread.uaccess_err ? -EFAULT : 0); \ |
| } while (0) |
| |
| /** |
| * __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. |
| * |
| * Returns 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. |
| * |
| * Returns zero on success, or -EFAULT on error. |
| */ |
| |
| #define __put_user(x, ptr) \ |
| __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) |
| |
| #define __get_user_unaligned __get_user |
| #define __put_user_unaligned __put_user |
| |
| /* |
| * {get|put}_user_try and catch |
| * |
| * get_user_try { |
| * get_user_ex(...); |
| * } get_user_catch(err) |
| */ |
| #define get_user_try uaccess_try |
| #define get_user_catch(err) uaccess_catch(err) |
| |
| #define get_user_ex(x, ptr) do { \ |
| unsigned long __gue_val; \ |
| __get_user_size_ex((__gue_val), (ptr), (sizeof(*(ptr)))); \ |
| (x) = (__force __typeof__(*(ptr)))__gue_val; \ |
| } while (0) |
| |
| #define put_user_try uaccess_try |
| #define put_user_catch(err) uaccess_catch(err) |
| |
| #define put_user_ex(x, ptr) \ |
| __put_user_size_ex((__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 |
| strncpy_from_user(char *dst, const char __user *src, long count); |
| |
| extern __must_check long strlen_user(const char __user *str); |
| 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); |
| |
| extern void __cmpxchg_wrong_size(void) |
| __compiletime_error("Bad argument size for cmpxchg"); |
| |
| #define __user_atomic_cmpxchg_inatomic(uval, ptr, old, new, size) \ |
| ({ \ |
| int __ret = 0; \ |
| __typeof__(ptr) __uval = (uval); \ |
| __typeof__(*(ptr)) __old = (old); \ |
| __typeof__(*(ptr)) __new = (new); \ |
| __uaccess_begin(); \ |
| switch (size) { \ |
| case 1: \ |
| { \ |
| asm volatile("\n" \ |
| "1:\t" LOCK_PREFIX "cmpxchgb %4, %2\n" \ |
| "2:\n" \ |
| "\t.section .fixup, \"ax\"\n" \ |
| "3:\tmov %3, %0\n" \ |
| "\tjmp 2b\n" \ |
| "\t.previous\n" \ |
| _ASM_EXTABLE(1b, 3b) \ |
| : "+r" (__ret), "=a" (__old), "+m" (*(ptr)) \ |
| : "i" (-EFAULT), "q" (__new), "1" (__old) \ |
| : "memory" \ |
| ); \ |
| break; \ |
| } \ |
| case 2: \ |
| { \ |
| asm volatile("\n" \ |
| "1:\t" LOCK_PREFIX "cmpxchgw %4, %2\n" \ |
| "2:\n" \ |
| "\t.section .fixup, \"ax\"\n" \ |
| "3:\tmov %3, %0\n" \ |
| "\tjmp 2b\n" \ |
| "\t.previous\n" \ |
| _ASM_EXTABLE(1b, 3b) \ |
| : "+r" (__ret), "=a" (__old), "+m" (*(ptr)) \ |
| : "i" (-EFAULT), "r" (__new), "1" (__old) \ |
| : "memory" \ |
| ); \ |
| break; \ |
| } \ |
| case 4: \ |
| { \ |
| asm volatile("\n" \ |
| "1:\t" LOCK_PREFIX "cmpxchgl %4, %2\n" \ |
| "2:\n" \ |
| "\t.section .fixup, \"ax\"\n" \ |
| "3:\tmov %3, %0\n" \ |
| "\tjmp 2b\n" \ |
| "\t.previous\n" \ |
| _ASM_EXTABLE(1b, 3b) \ |
| : "+r" (__ret), "=a" (__old), "+m" (*(ptr)) \ |
| : "i" (-EFAULT), "r" (__new), "1" (__old) \ |
| : "memory" \ |
| ); \ |
| break; \ |
| } \ |
| case 8: \ |
| { \ |
| if (!IS_ENABLED(CONFIG_X86_64)) \ |
| __cmpxchg_wrong_size(); \ |
| \ |
| asm volatile("\n" \ |
| "1:\t" LOCK_PREFIX "cmpxchgq %4, %2\n" \ |
| "2:\n" \ |
| "\t.section .fixup, \"ax\"\n" \ |
| "3:\tmov %3, %0\n" \ |
| "\tjmp 2b\n" \ |
| "\t.previous\n" \ |
| _ASM_EXTABLE(1b, 3b) \ |
| : "+r" (__ret), "=a" (__old), "+m" (*(ptr)) \ |
| : "i" (-EFAULT), "r" (__new), "1" (__old) \ |
| : "memory" \ |
| ); \ |
| break; \ |
| } \ |
| default: \ |
| __cmpxchg_wrong_size(); \ |
| } \ |
| __uaccess_end(); \ |
| *__uval = __old; \ |
| __ret; \ |
| }) |
| |
| #define user_atomic_cmpxchg_inatomic(uval, ptr, old, new) \ |
| ({ \ |
| access_ok(VERIFY_WRITE, (ptr), sizeof(*(ptr))) ? \ |
| __user_atomic_cmpxchg_inatomic((uval), (ptr), \ |
| (old), (new), sizeof(*(ptr))) : \ |
| -EFAULT; \ |
| }) |
| |
| /* |
| * movsl can be slow when source and dest are not both 8-byte aligned |
| */ |
| #ifdef CONFIG_X86_INTEL_USERCOPY |
| extern struct movsl_mask { |
| int mask; |
| } ____cacheline_aligned_in_smp movsl_mask; |
| #endif |
| |
| #define ARCH_HAS_NOCACHE_UACCESS 1 |
| |
| #ifdef CONFIG_X86_32 |
| # include <asm/uaccess_32.h> |
| #else |
| # include <asm/uaccess_64.h> |
| #endif |
| |
| unsigned long __must_check _copy_from_user(void *to, const void __user *from, |
| unsigned n); |
| unsigned long __must_check _copy_to_user(void __user *to, const void *from, |
| unsigned n); |
| |
| extern void __compiletime_error("usercopy buffer size is too small") |
| __bad_copy_user(void); |
| |
| static inline void copy_user_overflow(int size, unsigned long count) |
| { |
| WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count); |
| } |
| |
| static __always_inline unsigned long __must_check |
| copy_from_user(void *to, const void __user *from, unsigned long n) |
| { |
| int sz = __compiletime_object_size(to); |
| |
| might_fault(); |
| |
| kasan_check_write(to, n); |
| |
| if (likely(sz < 0 || sz >= n)) { |
| check_object_size(to, n, false); |
| n = _copy_from_user(to, from, n); |
| } else if (!__builtin_constant_p(n)) |
| copy_user_overflow(sz, n); |
| else |
| __bad_copy_user(); |
| |
| return n; |
| } |
| |
| static __always_inline unsigned long __must_check |
| copy_to_user(void __user *to, const void *from, unsigned long n) |
| { |
| int sz = __compiletime_object_size(from); |
| |
| kasan_check_read(from, n); |
| |
| might_fault(); |
| |
| if (likely(sz < 0 || sz >= n)) { |
| check_object_size(from, n, true); |
| n = _copy_to_user(to, from, n); |
| } else if (!__builtin_constant_p(n)) |
| copy_user_overflow(sz, n); |
| else |
| __bad_copy_user(); |
| |
| return n; |
| } |
| |
| /* |
| * We rely on the nested NMI work to allow atomic faults from the NMI path; the |
| * nested NMI paths are careful to preserve CR2. |
| * |
| * Caller must use pagefault_enable/disable, or run in interrupt context, |
| * and also do a uaccess_ok() check |
| */ |
| #define __copy_from_user_nmi __copy_from_user_inatomic |
| |
| /* |
| * The "unsafe" user accesses aren't really "unsafe", but the naming |
| * is a big fat warning: you have to not only do the access_ok() |
| * checking before using them, but you have to surround them with the |
| * user_access_begin/end() pair. |
| */ |
| #define user_access_begin() __uaccess_begin() |
| #define user_access_end() __uaccess_end() |
| |
| #define unsafe_put_user(x, ptr, err_label) \ |
| do { \ |
| int __pu_err; \ |
| __put_user_size((x), (ptr), sizeof(*(ptr)), __pu_err, -EFAULT); \ |
| if (unlikely(__pu_err)) goto err_label; \ |
| } while (0) |
| |
| #define unsafe_get_user(x, ptr, err_label) \ |
| do { \ |
| int __gu_err; \ |
| unsigned long __gu_val; \ |
| __get_user_size(__gu_val, (ptr), sizeof(*(ptr)), __gu_err, -EFAULT); \ |
| (x) = (__force __typeof__(*(ptr)))__gu_val; \ |
| if (unlikely(__gu_err)) goto err_label; \ |
| } while (0) |
| |
| #endif /* _ASM_X86_UACCESS_H */ |
| |