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Diffstat (limited to 'arch/score/include/asm/uaccess.h')
| -rw-r--r-- | arch/score/include/asm/uaccess.h | 424 |
1 files changed, 424 insertions, 0 deletions
diff --git a/arch/score/include/asm/uaccess.h b/arch/score/include/asm/uaccess.h new file mode 100644 index 000000000000..ab66ddde777b --- /dev/null +++ b/arch/score/include/asm/uaccess.h @@ -0,0 +1,424 @@ +#ifndef __SCORE_UACCESS_H +#define __SCORE_UACCESS_H + +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/thread_info.h> + +#define VERIFY_READ 0 +#define VERIFY_WRITE 1 + +#define get_ds() (KERNEL_DS) +#define get_fs() (current_thread_info()->addr_limit) +#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_ok(addr, size) \ + (((long)((get_fs().seg) & \ + ((addr) | ((addr) + (size)) | \ + __ua_size(size)))) == 0) + +#define access_ok(type, addr, size) \ + likely(__access_ok((unsigned long)(addr), (size))) + +/* + * 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. + */ +extern void __get_user_unknown(void); + +#define __get_user_common(val, size, ptr) \ +do { \ + switch (size) { \ + case 1: \ + __get_user_asm(val, "lb", ptr); \ + break; \ + case 2: \ + __get_user_asm(val, "lh", ptr); \ + break; \ + case 4: \ + __get_user_asm(val, "lw", ptr); \ + break; \ + case 8: \ + if ((copy_from_user((void *)&val, ptr, 8)) == 0) \ + __gu_err = 0; \ + else \ + __gu_err = -EFAULT; \ + break; \ + default: \ + __get_user_unknown(); \ + break; \ + } \ +} while (0) + +#define __get_user_nocheck(x, ptr, size) \ +({ \ + long __gu_err = 0; \ + __get_user_common((x), size, ptr); \ + __gu_err; \ +}) + +#define __get_user_check(x, ptr, size) \ +({ \ + long __gu_err = -EFAULT; \ + const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \ + \ + if (likely(access_ok(VERIFY_READ, __gu_ptr, size))) \ + __get_user_common((x), size, __gu_ptr); \ + \ + __gu_err; \ +}) + +#define __get_user_asm(val, insn, addr) \ +{ \ + long __gu_tmp; \ + \ + __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" \ + ".word 1b, 3b\n" \ + ".previous\n" \ + : "=r" (__gu_err), "=r" (__gu_tmp) \ + : "0" (0), "o" (__m(addr)), "i" (-EFAULT)); \ + \ + (val) = (__typeof__(*(addr))) __gu_tmp; \ +} + +/* + * Yuck. We need two variants, one for 64bit operation and one + * for 32 bit mode and old iron. + */ +#define __put_user_nocheck(val, ptr, size) \ +({ \ + __typeof__(*(ptr)) __pu_val; \ + long __pu_err = 0; \ + \ + __pu_val = (val); \ + 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: \ + if ((__copy_to_user((void *)ptr, &__pu_val, 8)) == 0) \ + __pu_err = 0; \ + else \ + __pu_err = -EFAULT; \ + break; \ + default: \ + __put_user_unknown(); \ + break; \ + } \ + __pu_err; \ +}) + + +#define __put_user_check(val, ptr, size) \ +({ \ + __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ + __typeof__(*(ptr)) __pu_val = (val); \ + 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: \ + if ((__copy_to_user((void *)__pu_addr, &__pu_val, 8)) == 0)\ + __pu_err = 0; \ + else \ + __pu_err = -EFAULT; \ + break; \ + default: \ + __put_user_unknown(); \ + break; \ + } \ + } \ + __pu_err; \ +}) + +#define __put_user_asm(insn, ptr) \ + __asm__ __volatile__( \ + "1:" insn " %2, %3\n" \ + "2:\n" \ + ".section .fixup,\"ax\"\n" \ + "3:li %0, %4\n" \ + "j 2b\n" \ + ".previous\n" \ + ".section __ex_table,\"a\"\n" \ + ".word 1b, 3b\n" \ + ".previous\n" \ + : "=r" (__pu_err) \ + : "0" (0), "r" (__pu_val), "o" (__m(ptr)), \ + "i" (-EFAULT)); + +extern void __put_user_unknown(void); +extern int __copy_tofrom_user(void *to, const void *from, unsigned long len); + +static inline unsigned long +copy_from_user(void *to, const void *from, unsigned long len) +{ + unsigned long over; + + if (access_ok(VERIFY_READ, from, len)) + return __copy_tofrom_user(to, from, len); + + if ((unsigned long)from < TASK_SIZE) { + over = (unsigned long)from + len - TASK_SIZE; + return __copy_tofrom_user(to, from, len - over) + over; + } + return len; +} + +static inline unsigned long +copy_to_user(void *to, const void *from, unsigned long len) +{ + unsigned long over; + + if (access_ok(VERIFY_WRITE, to, len)) + return __copy_tofrom_user(to, from, len); + + if ((unsigned long)to < TASK_SIZE) { + over = (unsigned long)to + len - TASK_SIZE; + return __copy_tofrom_user(to, from, len - over) + over; + } + return len; +} + +#define __copy_from_user(to, from, len) \ + __copy_tofrom_user((to), (from), (len)) + +#define __copy_to_user(to, from, len) \ + __copy_tofrom_user((to), (from), (len)) + +static inline unsigned long +__copy_to_user_inatomic(void *to, const void *from, unsigned long len) +{ + return __copy_to_user(to, from, len); +} + +static inline unsigned long +__copy_from_user_inatomic(void *to, const void *from, unsigned long len) +{ + return __copy_from_user(to, from, len); +} + +#define __copy_in_user(to, from, len) __copy_from_user(to, from, len) + +static inline unsigned long +copy_in_user(void *to, const void *from, unsigned long len) +{ + if (access_ok(VERIFY_READ, from, len) && + access_ok(VERFITY_WRITE, to, len)) + return copy_from_user(to, from, 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. + */ +extern unsigned long __clear_user(void __user *src, unsigned long size); + +static inline unsigned long clear_user(char *src, unsigned long size) +{ + if (access_ok(VERIFY_WRITE, src, size)) + return __clear_user(src, size); + + return -EFAULT; +} +/* + * __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. + */ +extern int __strncpy_from_user(char *dst, const char *src, long len); + +static inline int strncpy_from_user(char *dst, const char *src, long len) +{ + if (access_ok(VERIFY_READ, src, 1)) + return __strncpy_from_user(dst, src, len); + + return -EFAULT; +} + +extern int __strlen_user(const char *src); +static inline long strlen_user(const char __user *src) +{ + return __strlen_user(src); +} + +extern int __strnlen_user(const char *str, long len); +static inline long strnlen_user(const char __user *str, long len) +{ + if (!access_ok(VERIFY_READ, str, 0)) + return 0; + else + return __strnlen_user(str, len); +} + +struct exception_table_entry { + unsigned long insn; + unsigned long fixup; +}; + +extern int fixup_exception(struct pt_regs *regs); + +#endif /* __SCORE_UACCESS_H */ + |