/* * 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) #ifdef __s390x__ #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; \ asm volatile ("lctlg 7,7,%0" : : "m" (__pto) ); \ }) #else #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; \ asm volatile ("lctl 7,7,%0" : : "m" (__pto) ); \ }) #endif #define segment_eq(a,b) ((a).ar4 == (b).ar4) #define __access_ok(addr,size) (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; }; #ifndef __s390x__ #define __uaccess_fixup \ ".section .fixup,\"ax\"\n" \ "2: lhi %0,%4\n" \ " bras 1,3f\n" \ " .long 1b\n" \ "3: l 1,0(1)\n" \ " br 1\n" \ ".previous\n" \ ".section __ex_table,\"a\"\n" \ " .align 4\n" \ " .long 0b,2b\n" \ ".previous" #define __uaccess_clobber "cc", "1" #else /* __s390x__ */ #define __uaccess_fixup \ ".section .fixup,\"ax\"\n" \ "2: lghi %0,%4\n" \ " jg 1b\n" \ ".previous\n" \ ".section __ex_table,\"a\"\n" \ " .align 8\n" \ " .quad 0b,2b\n" \ ".previous" #define __uaccess_clobber "cc" #endif /* __s390x__ */ /* * These are the main single-value transfer routines. They automatically * use the right size if we just have the right pointer type. */ #if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2) #define __put_user_asm(x, ptr, err) \ ({ \ err = 0; \ asm volatile( \ "0: mvcs 0(%1,%2),%3,%0\n" \ "1:\n" \ __uaccess_fixup \ : "+&d" (err) \ : "d" (sizeof(*(ptr))), "a" (ptr), "Q" (x), \ "K" (-EFAULT) \ : __uaccess_clobber ); \ }) #else #define __put_user_asm(x, ptr, err) \ ({ \ err = 0; \ asm volatile( \ "0: mvcs 0(%1,%2),0(%3),%0\n" \ "1:\n" \ __uaccess_fixup \ : "+&d" (err) \ : "d" (sizeof(*(ptr))), "a" (ptr), "a" (&(x)), \ "K" (-EFAULT), "m" (x) \ : __uaccess_clobber ); \ }) #endif #define __put_user(x, ptr) \ ({ \ __typeof__(*(ptr)) __x = (x); \ int __pu_err; \ __chk_user_ptr(ptr); \ switch (sizeof (*(ptr))) { \ case 1: \ case 2: \ case 4: \ case 8: \ __put_user_asm(__x, ptr, __pu_err); \ 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)); #if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2) #define __get_user_asm(x, ptr, err) \ ({ \ err = 0; \ asm volatile ( \ "0: mvcp %O1(%2,%R1),0(%3),%0\n" \ "1:\n" \ __uaccess_fixup \ : "+&d" (err), "=Q" (x) \ : "d" (sizeof(*(ptr))), "a" (ptr), \ "K" (-EFAULT) \ : __uaccess_clobber ); \ }) #else #define __get_user_asm(x, ptr, err) \ ({ \ err = 0; \ asm volatile ( \ "0: mvcp 0(%2,%5),0(%3),%0\n" \ "1:\n" \ __uaccess_fixup \ : "+&d" (err), "=m" (x) \ : "d" (sizeof(*(ptr))), "a" (ptr), \ "K" (-EFAULT), "a" (&(x)) \ : __uaccess_clobber ); \ }) #endif #define __get_user(x, ptr) \ ({ \ int __gu_err; \ __chk_user_ptr(ptr); \ switch (sizeof(*(ptr))) { \ case 1: { \ unsigned char __x; \ __get_user_asm(__x, ptr, __gu_err); \ (x) = (__typeof__(*(ptr))) __x; \ break; \ }; \ case 2: { \ unsigned short __x; \ __get_user_asm(__x, ptr, __gu_err); \ (x) = (__typeof__(*(ptr))) __x; \ break; \ }; \ case 4: { \ unsigned int __x; \ __get_user_asm(__x, ptr, __gu_err); \ (x) = (__typeof__(*(ptr))) __x; \ break; \ }; \ case 8: { \ unsigned long long __x; \ __get_user_asm(__x, ptr, __gu_err); \ (x) = (__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 extern long __copy_to_user_asm(const void *from, long n, void __user *to); /** * __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 __copy_to_user(void __user *to, const void *from, unsigned long n) { return __copy_to_user_asm(from, n, to); } #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 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; } extern long __copy_from_user_asm(void *to, long n, const void __user *from); /** * __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 __copy_from_user(void *to, const void __user *from, unsigned long n) { return __copy_from_user_asm(to, n, from); } /** * 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 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; } extern unsigned long __copy_in_user_asm(const void __user *from, long n, void __user *to); static inline unsigned long __copy_in_user(void __user *to, const void __user *from, unsigned long n) { return __copy_in_user_asm(from, n, to); } static inline unsigned long 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_asm(from, n, to); return n; } /* * Copy a null terminated string from userspace. */ extern long __strncpy_from_user_asm(long count, char *dst, const char __user *src); static inline long strncpy_from_user(char *dst, const char __user *src, long count) { long res = -EFAULT; might_sleep(); if (access_ok(VERIFY_READ, src, 1)) res = __strncpy_from_user_asm(count, dst, src); return res; } extern long __strnlen_user_asm(long count, const char __user *src); static inline unsigned long strnlen_user(const char __user * src, unsigned long n) { might_sleep(); return __strnlen_user_asm(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 */ extern long __clear_user_asm(void __user *to, long n); static inline unsigned long __clear_user(void __user *to, unsigned long n) { return __clear_user_asm(to, n); } static inline unsigned long clear_user(void __user *to, unsigned long n) { might_sleep(); if (access_ok(VERIFY_WRITE, to, n)) n = __clear_user_asm(to, n); return n; } #endif /* __S390_UACCESS_H */