/* * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * Copyright (C) 1996, 1997, 1998, 1999, 2000, 03, 04 by Ralf Baechle * Copyright (C) 1999, 2000 Silicon Graphics, Inc. */ #ifndef _ASM_UACCESS_H #define _ASM_UACCESS_H #include <linux/config.h> #include <linux/kernel.h> #include <linux/errno.h> #include <linux/thread_info.h> #include <asm-generic/uaccess.h> /* * 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. */ #ifdef CONFIG_32BIT #define __UA_LIMIT 0x80000000UL #define __UA_ADDR ".word" #define __UA_LA "la" #define __UA_ADDU "addu" #define __UA_t0 "$8" #define __UA_t1 "$9" #endif /* CONFIG_32BIT */ #ifdef CONFIG_64BIT #define __UA_LIMIT (- TASK_SIZE) #define __UA_ADDR ".dword" #define __UA_LA "dla" #define __UA_ADDU "daddu" #define __UA_t0 "$12" #define __UA_t1 "$13" #endif /* CONFIG_64BIT */ /* * USER_DS is a bitmask that has the bits set that may not be set in a valid * userspace address. Note that we limit 32-bit userspace to 0x7fff8000 but * the arithmetic we're doing only works if the limit is a power of two, so * we use 0x80000000 here on 32-bit kernels. If a process passes an invalid * address in this range it's the process's problem, not ours :-) */ #define KERNEL_DS ((mm_segment_t) { 0UL }) #define USER_DS ((mm_segment_t) { __UA_LIMIT }) #define VERIFY_READ 0 #define VERIFY_WRITE 1 #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) /* * Is a address valid? This does a straighforward calculation rather * than tests. * * Address valid if: * - "addr" doesn't have any high-bits set * - AND "size" doesn't have any high-bits set * - AND "addr+size" doesn't have any high-bits set * - OR we are in kernel mode. * * __ua_size() is a trick to avoid runtime checking of positive constant * sizes; for those we already know at compile time that the size is ok. */ #define __ua_size(size) \ ((__builtin_constant_p(size) && (signed long) (size) > 0) ? 0 : (size)) /* * 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_mask get_fs().seg #define __access_ok(addr, size, mask) \ (((signed long)((mask) & ((addr) | ((addr) + (size)) | __ua_size(size)))) == 0) #define access_ok(type, addr, size) \ likely(__access_ok((unsigned long)(addr), (size),__access_mask)) /* * 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) \ __put_user_check((x),(ptr),sizeof(*(ptr))) /* * 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. */ #define get_user(x,ptr) \ __get_user_check((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((x),(ptr),sizeof(*(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. * * 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))) struct __large_struct { unsigned long buf[100]; }; #define __m(x) (*(struct __large_struct __user *)(x)) /* * Yuck. We need two variants, one for 64bit operation and one * for 32 bit mode and old iron. */ #ifdef __mips64 #define __GET_USER_DW(ptr) __get_user_asm("ld", ptr) #else #define __GET_USER_DW(ptr) __get_user_asm_ll32(ptr) #endif #define __get_user_nocheck(x,ptr,size) \ ({ \ __typeof(*(ptr)) __gu_val = (__typeof(*(ptr))) 0; \ long __gu_err = 0; \ \ switch (size) { \ case 1: __get_user_asm("lb", ptr); break; \ case 2: __get_user_asm("lh", ptr); break; \ case 4: __get_user_asm("lw", ptr); break; \ case 8: __GET_USER_DW(ptr); break; \ default: __get_user_unknown(); break; \ } \ (x) = (__typeof__(*(ptr))) __gu_val; \ __gu_err; \ }) #define __get_user_check(x,ptr,size) \ ({ \ const __typeof__(*(ptr)) __user * __gu_addr = (ptr); \ __typeof__(*(ptr)) __gu_val = 0; \ long __gu_err = -EFAULT; \ \ if (likely(access_ok(VERIFY_READ, __gu_addr, size))) { \ switch (size) { \ case 1: __get_user_asm("lb", __gu_addr); break; \ case 2: __get_user_asm("lh", __gu_addr); break; \ case 4: __get_user_asm("lw", __gu_addr); break; \ case 8: __GET_USER_DW(__gu_addr); break; \ default: __get_user_unknown(); break; \ } \ } \ (x) = (__typeof__(*(ptr))) __gu_val; \ __gu_err; \ }) #define __get_user_asm(insn, addr) \ { \ __asm__ __volatile__( \ "1: " insn " %1, %3 \n" \ "2: \n" \ " .section .fixup,\"ax\" \n" \ "3: li %0, %4 \n" \ " j 2b \n" \ " .previous \n" \ " .section __ex_table,\"a\" \n" \ " "__UA_ADDR "\t1b, 3b \n" \ " .previous \n" \ : "=r" (__gu_err), "=r" (__gu_val) \ : "0" (0), "o" (__m(addr)), "i" (-EFAULT)); \ } /* * Get a long long 64 using 32 bit registers. */ #define __get_user_asm_ll32(addr) \ { \ __asm__ __volatile__( \ "1: lw %1, (%3) \n" \ "2: lw %D1, 4(%3) \n" \ " move %0, $0 \n" \ "3: .section .fixup,\"ax\" \n" \ "4: li %0, %4 \n" \ " move %1, $0 \n" \ " move %D1, $0 \n" \ " j 3b \n" \ " .previous \n" \ " .section __ex_table,\"a\" \n" \ " " __UA_ADDR " 1b, 4b \n" \ " " __UA_ADDR " 2b, 4b \n" \ " .previous \n" \ : "=r" (__gu_err), "=&r" (__gu_val) \ : "0" (0), "r" (addr), "i" (-EFAULT)); \ } extern void __get_user_unknown(void); /* * Yuck. We need two variants, one for 64bit operation and one * for 32 bit mode and old iron. */ #ifdef __mips64 #define __PUT_USER_DW(ptr) __put_user_asm("sd", ptr) #else #define __PUT_USER_DW(ptr) __put_user_asm_ll32(ptr) #endif #define __put_user_nocheck(x,ptr,size) \ ({ \ __typeof__(*(ptr)) __pu_val; \ long __pu_err = 0; \ \ __pu_val = (x); \ switch (size) { \ case 1: __put_user_asm("sb", ptr); break; \ case 2: __put_user_asm("sh", ptr); break; \ case 4: __put_user_asm("sw", ptr); break; \ case 8: __PUT_USER_DW(ptr); break; \ default: __put_user_unknown(); break; \ } \ __pu_err; \ }) #define __put_user_check(x,ptr,size) \ ({ \ __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ __typeof__(*(ptr)) __pu_val = (x); \ long __pu_err = -EFAULT; \ \ if (likely(access_ok(VERIFY_WRITE, __pu_addr, size))) { \ switch (size) { \ case 1: __put_user_asm("sb", __pu_addr); break; \ case 2: __put_user_asm("sh", __pu_addr); break; \ case 4: __put_user_asm("sw", __pu_addr); break; \ case 8: __PUT_USER_DW(__pu_addr); break; \ default: __put_user_unknown(); break; \ } \ } \ __pu_err; \ }) #define __put_user_asm(insn, ptr) \ { \ __asm__ __volatile__( \ "1: " insn " %z2, %3 # __put_user_asm\n" \ "2: \n" \ " .section .fixup,\"ax\" \n" \ "3: li %0, %4 \n" \ " j 2b \n" \ " .previous \n" \ " .section __ex_table,\"a\" \n" \ " " __UA_ADDR " 1b, 3b \n" \ " .previous \n" \ : "=r" (__pu_err) \ : "0" (0), "Jr" (__pu_val), "o" (__m(ptr)), \ "i" (-EFAULT)); \ } #define __put_user_asm_ll32(ptr) \ { \ __asm__ __volatile__( \ "1: sw %2, (%3) # __put_user_asm_ll32 \n" \ "2: sw %D2, 4(%3) \n" \ "3: \n" \ " .section .fixup,\"ax\" \n" \ "4: li %0, %4 \n" \ " j 3b \n" \ " .previous \n" \ " .section __ex_table,\"a\" \n" \ " " __UA_ADDR " 1b, 4b \n" \ " " __UA_ADDR " 2b, 4b \n" \ " .previous" \ : "=r" (__pu_err) \ : "0" (0), "r" (__pu_val), "r" (ptr), \ "i" (-EFAULT)); \ } extern void __put_user_unknown(void); /* * We're generating jump to subroutines which will be outside the range of * jump instructions */ #ifdef MODULE #define __MODULE_JAL(destination) \ ".set\tnoat\n\t" \ __UA_LA "\t$1, " #destination "\n\t" \ "jalr\t$1\n\t" \ ".set\tat\n\t" #else #define __MODULE_JAL(destination) \ "jal\t" #destination "\n\t" #endif extern size_t __copy_user(void *__to, const void *__from, size_t __n); #define __invoke_copy_to_user(to,from,n) \ ({ \ register void __user *__cu_to_r __asm__ ("$4"); \ register const void *__cu_from_r __asm__ ("$5"); \ register long __cu_len_r __asm__ ("$6"); \ \ __cu_to_r = (to); \ __cu_from_r = (from); \ __cu_len_r = (n); \ __asm__ __volatile__( \ __MODULE_JAL(__copy_user) \ : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r) \ : \ : "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31", \ "memory"); \ __cu_len_r; \ }) /* * __copy_to_user: - Copy a block of data into user space, with less checking. * @to: Destination address, in user space. * @from: Source address, in kernel space. * @n: Number of bytes to copy. * * Context: User context only. This function may sleep. * * Copy data from kernel space to user space. Caller must check * the specified block with access_ok() before calling this function. * * Returns number of bytes that could not be copied. * On success, this will be zero. */ #define __copy_to_user(to,from,n) \ ({ \ void __user *__cu_to; \ const void *__cu_from; \ long __cu_len; \ \ might_sleep(); \ __cu_to = (to); \ __cu_from = (from); \ __cu_len = (n); \ __cu_len = __invoke_copy_to_user(__cu_to, __cu_from, __cu_len); \ __cu_len; \ }) #define __copy_to_user_inatomic __copy_to_user #define __copy_from_user_inatomic __copy_from_user /* * copy_to_user: - Copy a block of data into user space. * @to: Destination address, in user space. * @from: Source address, in kernel space. * @n: Number of bytes to copy. * * Context: User context only. This function may sleep. * * Copy data from kernel space to user space. * * Returns number of bytes that could not be copied. * On success, this will be zero. */ #define copy_to_user(to,from,n) \ ({ \ void __user *__cu_to; \ const void *__cu_from; \ long __cu_len; \ \ might_sleep(); \ __cu_to = (to); \ __cu_from = (from); \ __cu_len = (n); \ if (access_ok(VERIFY_WRITE, __cu_to, __cu_len)) \ __cu_len = __invoke_copy_to_user(__cu_to, __cu_from, \ __cu_len); \ __cu_len; \ }) #define __invoke_copy_from_user(to,from,n) \ ({ \ register void *__cu_to_r __asm__ ("$4"); \ register const void __user *__cu_from_r __asm__ ("$5"); \ register long __cu_len_r __asm__ ("$6"); \ \ __cu_to_r = (to); \ __cu_from_r = (from); \ __cu_len_r = (n); \ __asm__ __volatile__( \ ".set\tnoreorder\n\t" \ __MODULE_JAL(__copy_user) \ ".set\tnoat\n\t" \ __UA_ADDU "\t$1, %1, %2\n\t" \ ".set\tat\n\t" \ ".set\treorder" \ : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r) \ : \ : "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31", \ "memory"); \ __cu_len_r; \ }) /* * __copy_from_user: - Copy a block of data from user space, with less checking. * @to: Destination address, in kernel space. * @from: Source address, in user space. * @n: Number of bytes to copy. * * Context: User context only. This function may sleep. * * Copy data from user space to kernel space. Caller must check * the specified block with access_ok() before calling this function. * * Returns number of bytes that could not be copied. * On success, this will be zero. * * If some data could not be copied, this function will pad the copied * data to the requested size using zero bytes. */ #define __copy_from_user(to,from,n) \ ({ \ void *__cu_to; \ const void __user *__cu_from; \ long __cu_len; \ \ might_sleep(); \ __cu_to = (to); \ __cu_from = (from); \ __cu_len = (n); \ __cu_len = __invoke_copy_from_user(__cu_to, __cu_from, \ __cu_len); \ __cu_len; \ }) /* * copy_from_user: - Copy a block of data from user space. * @to: Destination address, in kernel space. * @from: Source address, in user space. * @n: Number of bytes to copy. * * Context: User context only. This function may sleep. * * Copy data from user space to kernel space. * * Returns number of bytes that could not be copied. * On success, this will be zero. * * If some data could not be copied, this function will pad the copied * data to the requested size using zero bytes. */ #define copy_from_user(to,from,n) \ ({ \ void *__cu_to; \ const void __user *__cu_from; \ long __cu_len; \ \ might_sleep(); \ __cu_to = (to); \ __cu_from = (from); \ __cu_len = (n); \ if (access_ok(VERIFY_READ, __cu_from, __cu_len)) \ __cu_len = __invoke_copy_from_user(__cu_to, __cu_from, \ __cu_len); \ __cu_len; \ }) #define __copy_in_user(to, from, n) __copy_from_user(to, from, n) #define copy_in_user(to,from,n) \ ({ \ void __user *__cu_to; \ const void __user *__cu_from; \ long __cu_len; \ \ might_sleep(); \ __cu_to = (to); \ __cu_from = (from); \ __cu_len = (n); \ if (likely(access_ok(VERIFY_READ, __cu_from, __cu_len) && \ access_ok(VERIFY_WRITE, __cu_to, __cu_len))) \ __cu_len = __invoke_copy_from_user(__cu_to, __cu_from, \ __cu_len); \ __cu_len; \ }) /* * __clear_user: - Zero a block of memory in user space, with less checking. * @to: Destination address, in user space. * @n: Number of bytes to zero. * * Zero a block of memory in user space. Caller must check * the specified block with access_ok() before calling this function. * * Returns number of bytes that could not be cleared. * On success, this will be zero. */ static inline __kernel_size_t __clear_user(void __user *addr, __kernel_size_t size) { __kernel_size_t res; might_sleep(); __asm__ __volatile__( "move\t$4, %1\n\t" "move\t$5, $0\n\t" "move\t$6, %2\n\t" __MODULE_JAL(__bzero) "move\t%0, $6" : "=r" (res) : "r" (addr), "r" (size) : "$4", "$5", "$6", __UA_t0, __UA_t1, "$31"); return res; } #define clear_user(addr,n) \ ({ \ void __user * __cl_addr = (addr); \ unsigned long __cl_size = (n); \ if (__cl_size && access_ok(VERIFY_WRITE, \ ((unsigned long)(__cl_addr)), __cl_size)) \ __cl_size = __clear_user(__cl_addr, __cl_size); \ __cl_size; \ }) /* * __strncpy_from_user: - Copy a NUL terminated string from userspace, with less checking. * @dst: Destination address, in kernel space. This buffer must be at * least @count bytes long. * @src: Source address, in user space. * @count: Maximum number of bytes to copy, including the trailing NUL. * * Copies a NUL-terminated string from userspace to kernel space. * Caller must check the specified block with access_ok() before calling * this function. * * On success, returns the length of the string (not including the trailing * NUL). * * If access to userspace fails, returns -EFAULT (some data may have been * copied). * * If @count is smaller than the length of the string, copies @count bytes * and returns @count. */ static inline long __strncpy_from_user(char *__to, const char __user *__from, long __len) { long res; might_sleep(); __asm__ __volatile__( "move\t$4, %1\n\t" "move\t$5, %2\n\t" "move\t$6, %3\n\t" __MODULE_JAL(__strncpy_from_user_nocheck_asm) "move\t%0, $2" : "=r" (res) : "r" (__to), "r" (__from), "r" (__len) : "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory"); return res; } /* * strncpy_from_user: - Copy a NUL terminated string from userspace. * @dst: Destination address, in kernel space. This buffer must be at * least @count bytes long. * @src: Source address, in user space. * @count: Maximum number of bytes to copy, including the trailing NUL. * * Copies a NUL-terminated string from userspace to kernel space. * * On success, returns the length of the string (not including the trailing * NUL). * * If access to userspace fails, returns -EFAULT (some data may have been * copied). * * If @count is smaller than the length of the string, copies @count bytes * and returns @count. */ static inline long strncpy_from_user(char *__to, const char __user *__from, long __len) { long res; might_sleep(); __asm__ __volatile__( "move\t$4, %1\n\t" "move\t$5, %2\n\t" "move\t$6, %3\n\t" __MODULE_JAL(__strncpy_from_user_asm) "move\t%0, $2" : "=r" (res) : "r" (__to), "r" (__from), "r" (__len) : "$2", "$3", "$4", "$5", "$6", __UA_t0, "$31", "memory"); return res; } /* Returns: 0 if bad, string length+1 (memory size) of string if ok */ static inline long __strlen_user(const char __user *s) { long res; might_sleep(); __asm__ __volatile__( "move\t$4, %1\n\t" __MODULE_JAL(__strlen_user_nocheck_asm) "move\t%0, $2" : "=r" (res) : "r" (s) : "$2", "$4", __UA_t0, "$31"); return res; } /* * strlen_user: - Get the size of a string in user space. * @str: The string to measure. * * Context: User context only. This function may sleep. * * Get the size of a NUL-terminated string in user space. * * Returns the size of the string INCLUDING the terminating NUL. * On exception, returns 0. * * If there is a limit on the length of a valid string, you may wish to * consider using strnlen_user() instead. */ static inline long strlen_user(const char __user *s) { long res; might_sleep(); __asm__ __volatile__( "move\t$4, %1\n\t" __MODULE_JAL(__strlen_user_asm) "move\t%0, $2" : "=r" (res) : "r" (s) : "$2", "$4", __UA_t0, "$31"); return res; } /* Returns: 0 if bad, string length+1 (memory size) of string if ok */ static inline long __strnlen_user(const char __user *s, long n) { long res; might_sleep(); __asm__ __volatile__( "move\t$4, %1\n\t" "move\t$5, %2\n\t" __MODULE_JAL(__strnlen_user_nocheck_asm) "move\t%0, $2" : "=r" (res) : "r" (s), "r" (n) : "$2", "$4", "$5", __UA_t0, "$31"); return res; } /* * strlen_user: - Get the size of a string in user space. * @str: The string to measure. * * Context: User context only. This function may sleep. * * Get the size of a NUL-terminated string in user space. * * Returns the size of the string INCLUDING the terminating NUL. * On exception, returns 0. * * If there is a limit on the length of a valid string, you may wish to * consider using strnlen_user() instead. */ static inline long strnlen_user(const char __user *s, long n) { long res; might_sleep(); __asm__ __volatile__( "move\t$4, %1\n\t" "move\t$5, %2\n\t" __MODULE_JAL(__strnlen_user_asm) "move\t%0, $2" : "=r" (res) : "r" (s), "r" (n) : "$2", "$4", "$5", __UA_t0, "$31"); return res; } struct exception_table_entry { unsigned long insn; unsigned long nextinsn; }; extern int fixup_exception(struct pt_regs *regs); #endif /* _ASM_UACCESS_H */