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Diffstat (limited to 'include/asm-mips/uaccess.h')
| -rw-r--r-- | include/asm-mips/uaccess.h | 830 |
1 files changed, 830 insertions, 0 deletions
diff --git a/include/asm-mips/uaccess.h b/include/asm-mips/uaccess.h new file mode 100644 index 00000000000..07114898e06 --- /dev/null +++ b/include/asm-mips/uaccess.h @@ -0,0 +1,830 @@ +/* + * 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_MIPS32 + +#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_MIPS32 */ + +#ifdef CONFIG_MIPS64 + +#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_MIPS64 */ + +/* + * 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)) + +/* + * verify_area: - Obsolete/deprecated and will go away soon, + * use access_ok() instead. + * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE + * @addr: User space pointer to start of block to check + * @size: Size of block to check + * + * Context: User context only. This function may sleep. + * + * This function has been replaced by access_ok(). + * + * Checks if a pointer to a block of memory in user space is valid. + * + * Returns zero if the memory block may be valid, -EFAULT + * if it is definitely invalid. + * + * See access_ok() for more details. + */ +static inline int __deprecated verify_area(int type, const void * addr, unsigned long size) +{ + return access_ok(type, addr, size) ? 0 : -EFAULT; +} + +/* + * 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 *)(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(__gu_err) __get_user_asm("ld", __gu_err) +#else +#define __GET_USER_DW(__gu_err) __get_user_asm_ll32(__gu_err) +#endif + +#define __get_user_nocheck(x,ptr,size) \ +({ \ + __typeof(*(ptr)) __gu_val = 0; \ + long __gu_addr; \ + long __gu_err = 0; \ + \ + might_sleep(); \ + __gu_addr = (long) (ptr); \ + switch (size) { \ + case 1: __get_user_asm("lb", __gu_err); break; \ + case 2: __get_user_asm("lh", __gu_err); break; \ + case 4: __get_user_asm("lw", __gu_err); break; \ + case 8: __GET_USER_DW(__gu_err); break; \ + default: __get_user_unknown(); break; \ + } \ + x = (__typeof__(*(ptr))) __gu_val; \ + __gu_err; \ +}) + +#define __get_user_check(x,ptr,size) \ +({ \ + __typeof__(*(ptr)) __gu_val = 0; \ + long __gu_addr; \ + long __gu_err; \ + \ + might_sleep(); \ + __gu_addr = (long) (ptr); \ + __gu_err = access_ok(VERIFY_READ, (void *) __gu_addr, size) \ + ? 0 : -EFAULT; \ + \ + if (likely(!__gu_err)) { \ + switch (size) { \ + case 1: __get_user_asm("lb", __gu_err); break; \ + case 2: __get_user_asm("lh", __gu_err); break; \ + case 4: __get_user_asm("lw", __gu_err); break; \ + case 8: __GET_USER_DW(__gu_err); break; \ + default: __get_user_unknown(); break; \ + } \ + } \ + x = (__typeof__(*(ptr))) __gu_val; \ + __gu_err; \ +}) + +#define __get_user_asm(insn,__gu_err) \ +({ \ + __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" (__gu_err), "o" (__m(__gu_addr)), "i" (-EFAULT)); \ +}) + +/* + * Get a long long 64 using 32 bit registers. + */ +#define __get_user_asm_ll32(__gu_err) \ +({ \ + __asm__ __volatile__( \ + "1: lw %1, %3 \n" \ + "2: lw %D1, %4 \n" \ + " move %0, $0 \n" \ + "3: .section .fixup,\"ax\" \n" \ + "4: li %0, %5 \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" (__gu_err), "o" (__m(__gu_addr)), \ + "o" (__m(__gu_addr + 4)), "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(__pu_val) __put_user_asm("sd", __pu_val) +#else +#define __PUT_USER_DW(__pu_val) __put_user_asm_ll32(__pu_val) +#endif + +#define __put_user_nocheck(x,ptr,size) \ +({ \ + __typeof__(*(ptr)) __pu_val; \ + long __pu_addr; \ + long __pu_err = 0; \ + \ + might_sleep(); \ + __pu_val = (x); \ + __pu_addr = (long) (ptr); \ + switch (size) { \ + case 1: __put_user_asm("sb", __pu_val); break; \ + case 2: __put_user_asm("sh", __pu_val); break; \ + case 4: __put_user_asm("sw", __pu_val); break; \ + case 8: __PUT_USER_DW(__pu_val); break; \ + default: __put_user_unknown(); break; \ + } \ + __pu_err; \ +}) + +#define __put_user_check(x,ptr,size) \ +({ \ + __typeof__(*(ptr)) __pu_val; \ + long __pu_addr; \ + long __pu_err; \ + \ + might_sleep(); \ + __pu_val = (x); \ + __pu_addr = (long) (ptr); \ + __pu_err = access_ok(VERIFY_WRITE, (void *) __pu_addr, size) \ + ? 0 : -EFAULT; \ + \ + if (likely(!__pu_err)) { \ + switch (size) { \ + case 1: __put_user_asm("sb", __pu_val); break; \ + case 2: __put_user_asm("sh", __pu_val); break; \ + case 4: __put_user_asm("sw", __pu_val); break; \ + case 8: __PUT_USER_DW(__pu_val); break; \ + default: __put_user_unknown(); break; \ + } \ + } \ + __pu_err; \ +}) + +#define __put_user_asm(insn, __pu_val) \ +({ \ + __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" (__pu_err), "Jr" (__pu_val), "o" (__m(__pu_addr)), \ + "i" (-EFAULT)); \ +}) + +#define __put_user_asm_ll32(__pu_val) \ +({ \ + __asm__ __volatile__( \ + "1: sw %2, %3 # __put_user_asm_ll32 \n" \ + "2: sw %D2, %4 \n" \ + "3: \n" \ + " .section .fixup,\"ax\" \n" \ + "4: li %0, %5 \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" (__pu_err), "r" (__pu_val), "o" (__m(__pu_addr)), \ + "o" (__m(__pu_addr + 4)), "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 *__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 *__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 *__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 *__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 *__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 *__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 *__cu_to; \ + const void *__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 *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 * __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 *__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 *__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 *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 *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 *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 *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 */ |