diff options
Diffstat (limited to 'arch/s390/include/asm/uaccess.h')
| -rw-r--r-- | arch/s390/include/asm/uaccess.h | 363 |
1 files changed, 363 insertions, 0 deletions
diff --git a/arch/s390/include/asm/uaccess.h b/arch/s390/include/asm/uaccess.h new file mode 100644 index 00000000000..0235970278f --- /dev/null +++ b/arch/s390/include/asm/uaccess.h @@ -0,0 +1,363 @@ +/* + * include/asm-s390/uaccess.h + * + * S390 version + * Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation + * Author(s): Hartmut Penner (hp@de.ibm.com), + * Martin Schwidefsky (schwidefsky@de.ibm.com) + * + * Derived from "include/asm-i386/uaccess.h" + */ +#ifndef __S390_UACCESS_H +#define __S390_UACCESS_H + +/* + * User space memory access functions + */ +#include <linux/sched.h> +#include <linux/errno.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(a) ((mm_segment_t) { (a) }) + + +#define KERNEL_DS MAKE_MM_SEG(0) +#define USER_DS MAKE_MM_SEG(1) + +#define get_ds() (KERNEL_DS) +#define get_fs() (current->thread.mm_segment) + +#define set_fs(x) \ +({ \ + unsigned long __pto; \ + current->thread.mm_segment = (x); \ + __pto = current->thread.mm_segment.ar4 ? \ + S390_lowcore.user_asce : S390_lowcore.kernel_asce; \ + __ctl_load(__pto, 7, 7); \ +}) + +#define segment_eq(a,b) ((a).ar4 == (b).ar4) + + +static inline int __access_ok(const void __user *addr, unsigned long size) +{ + return 1; +} +#define access_ok(type,addr,size) __access_ok(addr,size) + +/* + * The exception table consists of pairs of addresses: 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 +{ + unsigned long insn, fixup; +}; + +struct uaccess_ops { + size_t (*copy_from_user)(size_t, const void __user *, void *); + size_t (*copy_from_user_small)(size_t, const void __user *, void *); + size_t (*copy_to_user)(size_t, void __user *, const void *); + size_t (*copy_to_user_small)(size_t, void __user *, const void *); + size_t (*copy_in_user)(size_t, void __user *, const void __user *); + size_t (*clear_user)(size_t, void __user *); + size_t (*strnlen_user)(size_t, const char __user *); + size_t (*strncpy_from_user)(size_t, const char __user *, char *); + int (*futex_atomic_op)(int op, int __user *, int oparg, int *old); + int (*futex_atomic_cmpxchg)(int __user *, int old, int new); +}; + +extern struct uaccess_ops uaccess; +extern struct uaccess_ops uaccess_std; +extern struct uaccess_ops uaccess_mvcos; +extern struct uaccess_ops uaccess_mvcos_switch; +extern struct uaccess_ops uaccess_pt; + +static inline int __put_user_fn(size_t size, void __user *ptr, void *x) +{ + size = uaccess.copy_to_user_small(size, ptr, x); + return size ? -EFAULT : size; +} + +static inline int __get_user_fn(size_t size, const void __user *ptr, void *x) +{ + size = uaccess.copy_from_user_small(size, ptr, x); + return size ? -EFAULT : size; +} + +/* + * These are the main single-value transfer routines. They automatically + * use the right size if we just have the right pointer type. + */ +#define __put_user(x, ptr) \ +({ \ + __typeof__(*(ptr)) __x = (x); \ + int __pu_err = -EFAULT; \ + __chk_user_ptr(ptr); \ + switch (sizeof (*(ptr))) { \ + case 1: \ + case 2: \ + case 4: \ + case 8: \ + __pu_err = __put_user_fn(sizeof (*(ptr)), \ + ptr, &__x); \ + break; \ + default: \ + __put_user_bad(); \ + break; \ + } \ + __pu_err; \ +}) + +#define put_user(x, ptr) \ +({ \ + might_sleep(); \ + __put_user(x, ptr); \ +}) + + +extern int __put_user_bad(void) __attribute__((noreturn)); + +#define __get_user(x, ptr) \ +({ \ + int __gu_err = -EFAULT; \ + __chk_user_ptr(ptr); \ + switch (sizeof(*(ptr))) { \ + case 1: { \ + unsigned char __x; \ + __gu_err = __get_user_fn(sizeof (*(ptr)), \ + ptr, &__x); \ + (x) = *(__force __typeof__(*(ptr)) *) &__x; \ + break; \ + }; \ + case 2: { \ + unsigned short __x; \ + __gu_err = __get_user_fn(sizeof (*(ptr)), \ + ptr, &__x); \ + (x) = *(__force __typeof__(*(ptr)) *) &__x; \ + break; \ + }; \ + case 4: { \ + unsigned int __x; \ + __gu_err = __get_user_fn(sizeof (*(ptr)), \ + ptr, &__x); \ + (x) = *(__force __typeof__(*(ptr)) *) &__x; \ + break; \ + }; \ + case 8: { \ + unsigned long long __x; \ + __gu_err = __get_user_fn(sizeof (*(ptr)), \ + ptr, &__x); \ + (x) = *(__force __typeof__(*(ptr)) *) &__x; \ + break; \ + }; \ + default: \ + __get_user_bad(); \ + break; \ + } \ + __gu_err; \ +}) + +#define get_user(x, ptr) \ +({ \ + might_sleep(); \ + __get_user(x, ptr); \ +}) + +extern int __get_user_bad(void) __attribute__((noreturn)); + +#define __put_user_unaligned __put_user +#define __get_user_unaligned __get_user + +/** + * __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. + */ +static inline unsigned long __must_check +__copy_to_user(void __user *to, const void *from, unsigned long n) +{ + if (__builtin_constant_p(n) && (n <= 256)) + return uaccess.copy_to_user_small(n, to, from); + else + return uaccess.copy_to_user(n, to, from); +} + +#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. + */ +static inline unsigned long __must_check +copy_to_user(void __user *to, const void *from, unsigned long n) +{ + might_sleep(); + if (access_ok(VERIFY_WRITE, to, n)) + n = __copy_to_user(to, from, n); + return n; +} + +/** + * __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. + */ +static inline unsigned long __must_check +__copy_from_user(void *to, const void __user *from, unsigned long n) +{ + if (__builtin_constant_p(n) && (n <= 256)) + return uaccess.copy_from_user_small(n, from, to); + else + return uaccess.copy_from_user(n, from, to); +} + +/** + * 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. + */ +static inline unsigned long __must_check +copy_from_user(void *to, const void __user *from, unsigned long n) +{ + might_sleep(); + if (access_ok(VERIFY_READ, from, n)) + n = __copy_from_user(to, from, n); + else + memset(to, 0, n); + return n; +} + +static inline unsigned long __must_check +__copy_in_user(void __user *to, const void __user *from, unsigned long n) +{ + return uaccess.copy_in_user(n, to, from); +} + +static inline unsigned long __must_check +copy_in_user(void __user *to, const void __user *from, unsigned long n) +{ + might_sleep(); + if (__access_ok(from,n) && __access_ok(to,n)) + n = __copy_in_user(to, from, n); + return n; +} + +/* + * Copy a null terminated string from userspace. + */ +static inline long __must_check +strncpy_from_user(char *dst, const char __user *src, long count) +{ + long res = -EFAULT; + might_sleep(); + if (access_ok(VERIFY_READ, src, 1)) + res = uaccess.strncpy_from_user(count, src, dst); + return res; +} + +static inline unsigned long +strnlen_user(const char __user * src, unsigned long n) +{ + might_sleep(); + return uaccess.strnlen_user(n, src); +} + +/** + * 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. + */ +#define strlen_user(str) strnlen_user(str, ~0UL) + +/* + * Zero Userspace + */ + +static inline unsigned long __must_check +__clear_user(void __user *to, unsigned long n) +{ + return uaccess.clear_user(n, to); +} + +static inline unsigned long __must_check +clear_user(void __user *to, unsigned long n) +{ + might_sleep(); + if (access_ok(VERIFY_WRITE, to, n)) + n = uaccess.clear_user(n, to); + return n; +} + +#endif /* __S390_UACCESS_H */ |