/* uaccess.h: userspace accessor functions * * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #ifndef _ASM_UACCESS_H #define _ASM_UACCESS_H /* * User space memory access functions */ #include <linux/sched.h> #include <linux/mm.h> #include <asm/segment.h> #include <asm/sections.h> #define HAVE_ARCH_UNMAPPED_AREA /* we decide where to put mmaps */ #define __ptr(x) ((unsigned long __force *)(x)) #define VERIFY_READ 0 #define VERIFY_WRITE 1 #define __addr_ok(addr) ((unsigned long)(addr) < get_addr_limit()) /* * check that a range of addresses falls within the current address limit */ static inline int ___range_ok(unsigned long addr, unsigned long size) { #ifdef CONFIG_MMU int flag = -EFAULT, tmp; asm volatile ( " addcc %3,%2,%1,icc0 \n" /* set C-flag if addr+size>4GB */ " subcc.p %1,%4,gr0,icc1 \n" /* jump if addr+size>limit */ " bc icc0,#0,0f \n" " bhi icc1,#0,0f \n" " setlos #0,%0 \n" /* mark okay */ "0: \n" : "=r"(flag), "=&r"(tmp) : "r"(addr), "r"(size), "r"(get_addr_limit()), "0"(flag) ); return flag; #else if (addr < memory_start || addr > memory_end || size > memory_end - memory_start || addr + size > memory_end) return -EFAULT; return 0; #endif } #define __range_ok(addr,size) ___range_ok((unsigned long) (addr), (unsigned long) (size)) #define access_ok(type,addr,size) (__range_ok((void __user *)(addr), (size)) == 0) #define __access_ok(addr,size) (__range_ok((addr), (size)) == 0) /* * 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; }; /* Returns 0 if exception not found and fixup otherwise. */ extern unsigned long search_exception_table(unsigned long); /* * 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) \ ({ \ int __pu_err = 0; \ \ typeof(*(ptr)) __pu_val = (x); \ __chk_user_ptr(ptr); \ \ switch (sizeof (*(ptr))) { \ case 1: \ __put_user_asm(__pu_err, __pu_val, ptr, "b", "r"); \ break; \ case 2: \ __put_user_asm(__pu_err, __pu_val, ptr, "h", "r"); \ break; \ case 4: \ __put_user_asm(__pu_err, __pu_val, ptr, "", "r"); \ break; \ case 8: \ __put_user_asm(__pu_err, __pu_val, ptr, "d", "e"); \ break; \ default: \ __pu_err = __put_user_bad(); \ break; \ } \ __pu_err; \ }) #define put_user(x, ptr) \ ({ \ typeof(*(ptr)) __user *_p = (ptr); \ int _e; \ \ _e = __range_ok(_p, sizeof(*_p)); \ if (_e == 0) \ _e = __put_user((x), _p); \ _e; \ }) extern int __put_user_bad(void); /* * Tell gcc we read from memory instead of writing: this is because * we do not write to any memory gcc knows about, so there are no * aliasing issues. */ #ifdef CONFIG_MMU #define __put_user_asm(err,x,ptr,dsize,constraint) \ do { \ asm volatile("1: st"dsize"%I1 %2,%M1 \n" \ "2: \n" \ ".subsection 2 \n" \ "3: setlos %3,%0 \n" \ " bra 2b \n" \ ".previous \n" \ ".section __ex_table,\"a\" \n" \ " .balign 8 \n" \ " .long 1b,3b \n" \ ".previous" \ : "=r" (err) \ : "m" (*__ptr(ptr)), constraint (x), "i"(-EFAULT), "0"(err) \ : "memory"); \ } while (0) #else #define __put_user_asm(err,x,ptr,bwl,con) \ do { \ asm(" st"bwl"%I0 %1,%M0 \n" \ " membar \n" \ : \ : "m" (*__ptr(ptr)), con (x) \ : "memory"); \ } while (0) #endif /*****************************************************************************/ /* * */ #define __get_user(x, ptr) \ ({ \ int __gu_err = 0; \ __chk_user_ptr(ptr); \ \ switch (sizeof(*(ptr))) { \ case 1: { \ unsigned char __gu_val; \ __get_user_asm(__gu_err, __gu_val, ptr, "ub", "=r"); \ (x) = *(__force __typeof__(*(ptr)) *) &__gu_val; \ break; \ } \ case 2: { \ unsigned short __gu_val; \ __get_user_asm(__gu_err, __gu_val, ptr, "uh", "=r"); \ (x) = *(__force __typeof__(*(ptr)) *) &__gu_val; \ break; \ } \ case 4: { \ unsigned int __gu_val; \ __get_user_asm(__gu_err, __gu_val, ptr, "", "=r"); \ (x) = *(__force __typeof__(*(ptr)) *) &__gu_val; \ break; \ } \ case 8: { \ unsigned long long __gu_val; \ __get_user_asm(__gu_err, __gu_val, ptr, "d", "=e"); \ (x) = *(__force __typeof__(*(ptr)) *) &__gu_val; \ break; \ } \ default: \ __gu_err = __get_user_bad(); \ break; \ } \ __gu_err; \ }) #define get_user(x, ptr) \ ({ \ const typeof(*(ptr)) __user *_p = (ptr);\ int _e; \ \ _e = __range_ok(_p, sizeof(*_p)); \ if (likely(_e == 0)) \ _e = __get_user((x), _p); \ else \ (x) = (typeof(x)) 0; \ _e; \ }) extern int __get_user_bad(void); #ifdef CONFIG_MMU #define __get_user_asm(err,x,ptr,dtype,constraint) \ do { \ asm("1: ld"dtype"%I2 %M2,%1 \n" \ "2: \n" \ ".subsection 2 \n" \ "3: setlos %3,%0 \n" \ " setlos #0,%1 \n" \ " bra 2b \n" \ ".previous \n" \ ".section __ex_table,\"a\" \n" \ " .balign 8 \n" \ " .long 1b,3b \n" \ ".previous" \ : "=r" (err), constraint (x) \ : "m" (*__ptr(ptr)), "i"(-EFAULT), "0"(err) \ ); \ } while(0) #else #define __get_user_asm(err,x,ptr,bwl,con) \ asm(" ld"bwl"%I1 %M1,%0 \n" \ " membar \n" \ : con(x) \ : "m" (*__ptr(ptr))) #endif /*****************************************************************************/ /* * */ #define ____force(x) (__force void *)(void __user *)(x) #ifdef CONFIG_MMU extern long __memset_user(void *dst, unsigned long count); extern long __memcpy_user(void *dst, const void *src, unsigned long count); #define clear_user(dst,count) __memset_user(____force(dst), (count)) #define __copy_from_user_inatomic(to, from, n) __memcpy_user((to), ____force(from), (n)) #define __copy_to_user_inatomic(to, from, n) __memcpy_user(____force(to), (from), (n)) #else #define clear_user(dst,count) (memset(____force(dst), 0, (count)), 0) #define __copy_from_user_inatomic(to, from, n) (memcpy((to), ____force(from), (n)), 0) #define __copy_to_user_inatomic(to, from, n) (memcpy(____force(to), (from), (n)), 0) #endif #define __clear_user clear_user static inline unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n) { might_sleep(); return __copy_to_user_inatomic(to, from, n); } static inline unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n) { might_sleep(); return __copy_from_user_inatomic(to, from, n); } static inline long copy_from_user(void *to, const void __user *from, unsigned long n) { unsigned long ret = n; if (likely(__access_ok(from, n))) ret = __copy_from_user(to, from, n); if (unlikely(ret != 0)) memset(to + (n - ret), 0, ret); return ret; } static inline long copy_to_user(void __user *to, const void *from, unsigned long n) { return likely(__access_ok(to, n)) ? __copy_to_user(to, from, n) : n; } extern long strncpy_from_user(char *dst, const char __user *src, long count); extern long strnlen_user(const char __user *src, long count); #define strlen_user(str) strnlen_user(str, 32767) extern unsigned long search_exception_table(unsigned long addr); #endif /* _ASM_UACCESS_H */