| #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/thread_info.h> |
| #include <linux/string.h> |
| #include <asm/asm.h> |
| #include <asm/page.h> |
| #include <asm/smap.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_info()->addr_limit) |
| #define set_fs(x) (current_thread_info()->addr_limit = (x)) |
| |
| #define segment_eq(a, b) ((a).seg == (b).seg) |
| |
| #define user_addr_max() (current_thread_info()->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. |
| * |
| * This is equivalent to the following test: |
| * (u33)addr + (u33)size > (u33)current->addr_limit.seg (u65 for x86_64) |
| * |
| * This needs 33-bit (65-bit for x86_64) arithmetic. We have a carry... |
| */ |
| |
| #define __range_not_ok(addr, size, limit) \ |
| ({ \ |
| unsigned long flag, roksum; \ |
| __chk_user_ptr(addr); \ |
| asm("add %3,%1 ; sbb %0,%0 ; cmp %1,%4 ; sbb $0,%0" \ |
| : "=&r" (flag), "=r" (roksum) \ |
| : "1" (addr), "g" ((long)(size)), \ |
| "rm" (limit)); \ |
| flag; \ |
| }) |
| |
| /** |
| * 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. |
| * |
| * 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()) == 0)) |
| |
| /* |
| * The exception table consists of pairs of addresses relative to the |
| * exception table enty itself: the first is the address of an |
| * instruction that is allowed to fault, and the second is the address |
| * at which the program should continue. No registers are modified, |
| * so it is entirely up to the continuation code to figure out what to |
| * do. |
| * |
| * All the routines below use bits of fixup code that are out of line |
| * with the main instruction path. This means when everything is well, |
| * we don't even have to jump over them. Further, they do not intrude |
| * on our cache or tlb entries. |
| */ |
| |
| struct exception_table_entry { |
| int insn, fixup; |
| }; |
| /* This is not the generic standard exception_table_entry format */ |
| #define ARCH_HAS_SORT_EXTABLE |
| #define ARCH_HAS_SEARCH_EXTABLE |
| |
| extern int fixup_exception(struct pt_regs *regs); |
| extern int early_fixup_exception(unsigned long *ip); |
| |
| /* |
| * 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); |
| |
| /* |
| * 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. |
| * |
| * 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); \ |
| __chk_user_ptr(ptr); \ |
| might_fault(); \ |
| asm volatile("call __get_user_%P3" \ |
| : "=a" (__ret_gu), "=r" (__val_gu) \ |
| : "0" (ptr), "i" (sizeof(*(ptr)))); \ |
| (x) = (__typeof__(*(ptr))) __val_gu; \ |
| __ret_gu; \ |
| }) |
| |
| #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(ASM_STAC "\n" \ |
| "1: movl %%eax,0(%2)\n" \ |
| "2: movl %%edx,4(%2)\n" \ |
| "3: " ASM_CLAC "\n" \ |
| ".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(ASM_STAC "\n" \ |
| "1: movl %%eax,0(%1)\n" \ |
| "2: movl %%edx,4(%1)\n" \ |
| "3: " ASM_CLAC "\n" \ |
| _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. |
| * |
| * 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; \ |
| } \ |
| __ret_pu; \ |
| }) |
| |
| #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) |
| |
| #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) (x) = __get_user_bad() |
| #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(ASM_STAC "\n" \ |
| "1: mov"itype" %2,%"rtype"1\n" \ |
| "2: " ASM_CLAC "\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)) |
| |
| #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" \ |
| _ASM_EXTABLE_EX(1b, 2b) \ |
| : ltype(x) : "m" (__m(addr))) |
| |
| #define __put_user_nocheck(x, ptr, size) \ |
| ({ \ |
| int __pu_err; \ |
| __put_user_size((x), (ptr), (size), __pu_err, -EFAULT); \ |
| __pu_err; \ |
| }) |
| |
| #define __get_user_nocheck(x, ptr, size) \ |
| ({ \ |
| int __gu_err; \ |
| unsigned long __gu_val; \ |
| __get_user_size(__gu_val, (ptr), (size), __gu_err, -EFAULT); \ |
| (x) = (__force __typeof__(*(ptr)))__gu_val; \ |
| __gu_err; \ |
| }) |
| |
| /* 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(ASM_STAC "\n" \ |
| "1: mov"itype" %"rtype"1,%2\n" \ |
| "2: " ASM_CLAC "\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_info()->uaccess_err = 0; \ |
| stac(); \ |
| barrier(); |
| |
| #define uaccess_catch(err) \ |
| clac(); \ |
| (err) |= (current_thread_info()->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. |
| * |
| * 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. |
| * |
| * 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); |
| |
| /* |
| * 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 |
| |
| #endif /* _ASM_X86_UACCESS_H */ |
| |