Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* uaccess.h: userspace accessor functions |
| 2 | * |
| 3 | * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. |
| 4 | * Written by David Howells (dhowells@redhat.com) |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU General Public License |
| 8 | * as published by the Free Software Foundation; either version |
| 9 | * 2 of the License, or (at your option) any later version. |
| 10 | */ |
| 11 | |
| 12 | #ifndef _ASM_UACCESS_H |
| 13 | #define _ASM_UACCESS_H |
| 14 | |
| 15 | /* |
| 16 | * User space memory access functions |
| 17 | */ |
| 18 | #include <linux/sched.h> |
| 19 | #include <linux/mm.h> |
| 20 | #include <asm/segment.h> |
| 21 | #include <asm/sections.h> |
| 22 | |
| 23 | #define HAVE_ARCH_UNMAPPED_AREA /* we decide where to put mmaps */ |
| 24 | |
| 25 | #define __ptr(x) ((unsigned long *)(x)) |
| 26 | |
| 27 | #define VERIFY_READ 0 |
| 28 | #define VERIFY_WRITE 1 |
| 29 | |
| 30 | #define __addr_ok(addr) ((unsigned long)(addr) < get_addr_limit()) |
| 31 | |
| 32 | /* |
| 33 | * check that a range of addresses falls within the current address limit |
| 34 | */ |
| 35 | static inline int ___range_ok(unsigned long addr, unsigned long size) |
| 36 | { |
| 37 | #ifdef CONFIG_MMU |
| 38 | int flag = -EFAULT, tmp; |
| 39 | |
| 40 | asm volatile ( |
| 41 | " addcc %3,%2,%1,icc0 \n" /* set C-flag if addr+size>4GB */ |
| 42 | " subcc.p %1,%4,gr0,icc1 \n" /* jump if addr+size>limit */ |
| 43 | " bc icc0,#0,0f \n" |
| 44 | " bhi icc1,#0,0f \n" |
| 45 | " setlos #0,%0 \n" /* mark okay */ |
| 46 | "0: \n" |
| 47 | : "=r"(flag), "=&r"(tmp) |
| 48 | : "r"(addr), "r"(size), "r"(get_addr_limit()), "0"(flag) |
| 49 | ); |
| 50 | |
| 51 | return flag; |
| 52 | |
| 53 | #else |
| 54 | |
| 55 | if (addr < memory_start || |
| 56 | addr > memory_end || |
| 57 | size > memory_end - memory_start || |
| 58 | addr + size > memory_end) |
| 59 | return -EFAULT; |
| 60 | |
| 61 | return 0; |
| 62 | #endif |
| 63 | } |
| 64 | |
| 65 | #define __range_ok(addr,size) ___range_ok((unsigned long) (addr), (unsigned long) (size)) |
| 66 | |
| 67 | #define access_ok(type,addr,size) (__range_ok((addr), (size)) == 0) |
| 68 | #define __access_ok(addr,size) (__range_ok((addr), (size)) == 0) |
| 69 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 70 | /* |
| 71 | * The exception table consists of pairs of addresses: the first is the |
| 72 | * address of an instruction that is allowed to fault, and the second is |
| 73 | * the address at which the program should continue. No registers are |
| 74 | * modified, so it is entirely up to the continuation code to figure out |
| 75 | * what to do. |
| 76 | * |
| 77 | * All the routines below use bits of fixup code that are out of line |
| 78 | * with the main instruction path. This means when everything is well, |
| 79 | * we don't even have to jump over them. Further, they do not intrude |
| 80 | * on our cache or tlb entries. |
| 81 | */ |
| 82 | struct exception_table_entry |
| 83 | { |
| 84 | unsigned long insn, fixup; |
| 85 | }; |
| 86 | |
| 87 | /* Returns 0 if exception not found and fixup otherwise. */ |
| 88 | extern unsigned long search_exception_table(unsigned long); |
| 89 | |
| 90 | |
| 91 | /* |
| 92 | * These are the main single-value transfer routines. They automatically |
| 93 | * use the right size if we just have the right pointer type. |
| 94 | */ |
| 95 | #define __put_user(x, ptr) \ |
| 96 | ({ \ |
| 97 | int __pu_err = 0; \ |
| 98 | \ |
| 99 | typeof(*(ptr)) __pu_val = (x); \ |
| 100 | \ |
| 101 | switch (sizeof (*(ptr))) { \ |
| 102 | case 1: \ |
| 103 | __put_user_asm(__pu_err, __pu_val, ptr, "b", "r"); \ |
| 104 | break; \ |
| 105 | case 2: \ |
| 106 | __put_user_asm(__pu_err, __pu_val, ptr, "h", "r"); \ |
| 107 | break; \ |
| 108 | case 4: \ |
| 109 | __put_user_asm(__pu_err, __pu_val, ptr, "", "r"); \ |
| 110 | break; \ |
| 111 | case 8: \ |
| 112 | __put_user_asm(__pu_err, __pu_val, ptr, "d", "e"); \ |
| 113 | break; \ |
| 114 | default: \ |
| 115 | __pu_err = __put_user_bad(); \ |
| 116 | break; \ |
| 117 | } \ |
| 118 | __pu_err; \ |
| 119 | }) |
| 120 | |
| 121 | #define put_user(x, ptr) \ |
| 122 | ({ \ |
| 123 | typeof(&*ptr) _p = (ptr); \ |
| 124 | int _e; \ |
| 125 | \ |
| 126 | _e = __range_ok(_p, sizeof(*_p)); \ |
| 127 | if (_e == 0) \ |
| 128 | _e = __put_user((x), _p); \ |
| 129 | _e; \ |
| 130 | }) |
| 131 | |
| 132 | extern int __put_user_bad(void); |
| 133 | |
| 134 | /* |
| 135 | * Tell gcc we read from memory instead of writing: this is because |
| 136 | * we do not write to any memory gcc knows about, so there are no |
| 137 | * aliasing issues. |
| 138 | */ |
| 139 | |
| 140 | #ifdef CONFIG_MMU |
| 141 | |
| 142 | #define __put_user_asm(err,x,ptr,dsize,constraint) \ |
| 143 | do { \ |
| 144 | asm volatile("1: st"dsize"%I1 %2,%M1 \n" \ |
| 145 | "2: \n" \ |
| 146 | ".subsection 2 \n" \ |
| 147 | "3: setlos %3,%0 \n" \ |
| 148 | " bra 2b \n" \ |
| 149 | ".previous \n" \ |
| 150 | ".section __ex_table,\"a\" \n" \ |
| 151 | " .balign 8 \n" \ |
| 152 | " .long 1b,3b \n" \ |
| 153 | ".previous" \ |
| 154 | : "=r" (err) \ |
| 155 | : "m" (*__ptr(ptr)), constraint (x), "i"(-EFAULT), "0"(err) \ |
| 156 | : "memory"); \ |
| 157 | } while (0) |
| 158 | |
| 159 | #else |
| 160 | |
| 161 | #define __put_user_asm(err,x,ptr,bwl,con) \ |
| 162 | do { \ |
| 163 | asm(" st"bwl"%I0 %1,%M0 \n" \ |
| 164 | " membar \n" \ |
| 165 | : \ |
| 166 | : "m" (*__ptr(ptr)), con (x) \ |
| 167 | : "memory"); \ |
| 168 | } while (0) |
| 169 | |
| 170 | #endif |
| 171 | |
| 172 | /*****************************************************************************/ |
| 173 | /* |
| 174 | * |
| 175 | */ |
| 176 | #define __get_user(x, ptr) \ |
| 177 | ({ \ |
| 178 | typeof(*(ptr)) __gu_val = 0; \ |
| 179 | int __gu_err = 0; \ |
| 180 | \ |
| 181 | switch (sizeof(*(ptr))) { \ |
| 182 | case 1: \ |
David Howells | 5c15d41 | 2006-01-08 01:01:24 -0800 | [diff] [blame] | 183 | __get_user_asm(__gu_err, *(u8*)&__gu_val, ptr, "ub", "=r"); \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 184 | break; \ |
| 185 | case 2: \ |
David Howells | 5c15d41 | 2006-01-08 01:01:24 -0800 | [diff] [blame] | 186 | __get_user_asm(__gu_err, *(u16*)&__gu_val, ptr, "uh", "=r"); \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 187 | break; \ |
| 188 | case 4: \ |
David Howells | 5c15d41 | 2006-01-08 01:01:24 -0800 | [diff] [blame] | 189 | __get_user_asm(__gu_err, *(u32*)&__gu_val, ptr, "", "=r"); \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 190 | break; \ |
| 191 | case 8: \ |
David Howells | 5c15d41 | 2006-01-08 01:01:24 -0800 | [diff] [blame] | 192 | __get_user_asm(__gu_err, *(u64*)&__gu_val, ptr, "d", "=e"); \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 193 | break; \ |
| 194 | default: \ |
| 195 | __gu_err = __get_user_bad(); \ |
| 196 | break; \ |
| 197 | } \ |
| 198 | (x) = __gu_val; \ |
| 199 | __gu_err; \ |
| 200 | }) |
| 201 | |
| 202 | #define get_user(x, ptr) \ |
| 203 | ({ \ |
| 204 | typeof(&*ptr) _p = (ptr); \ |
| 205 | int _e; \ |
| 206 | \ |
| 207 | _e = __range_ok(_p, sizeof(*_p)); \ |
| 208 | if (likely(_e == 0)) \ |
| 209 | _e = __get_user((x), _p); \ |
| 210 | else \ |
| 211 | (x) = (typeof(x)) 0; \ |
| 212 | _e; \ |
| 213 | }) |
| 214 | |
| 215 | extern int __get_user_bad(void); |
| 216 | |
| 217 | #ifdef CONFIG_MMU |
| 218 | |
| 219 | #define __get_user_asm(err,x,ptr,dtype,constraint) \ |
| 220 | do { \ |
| 221 | asm("1: ld"dtype"%I2 %M2,%1 \n" \ |
| 222 | "2: \n" \ |
| 223 | ".subsection 2 \n" \ |
| 224 | "3: setlos %3,%0 \n" \ |
| 225 | " setlos #0,%1 \n" \ |
| 226 | " bra 2b \n" \ |
| 227 | ".previous \n" \ |
| 228 | ".section __ex_table,\"a\" \n" \ |
| 229 | " .balign 8 \n" \ |
| 230 | " .long 1b,3b \n" \ |
| 231 | ".previous" \ |
| 232 | : "=r" (err), constraint (x) \ |
| 233 | : "m" (*__ptr(ptr)), "i"(-EFAULT), "0"(err) \ |
| 234 | ); \ |
| 235 | } while(0) |
| 236 | |
| 237 | #else |
| 238 | |
| 239 | #define __get_user_asm(err,x,ptr,bwl,con) \ |
| 240 | asm(" ld"bwl"%I1 %M1,%0 \n" \ |
| 241 | " membar \n" \ |
| 242 | : con(x) \ |
| 243 | : "m" (*__ptr(ptr))) |
| 244 | |
| 245 | #endif |
| 246 | |
| 247 | /*****************************************************************************/ |
| 248 | /* |
| 249 | * |
| 250 | */ |
| 251 | #ifdef CONFIG_MMU |
| 252 | extern long __memset_user(void *dst, unsigned long count); |
| 253 | extern long __memcpy_user(void *dst, const void *src, unsigned long count); |
| 254 | |
| 255 | #define clear_user(dst,count) __memset_user((dst), (count)) |
| 256 | #define __copy_from_user_inatomic(to, from, n) __memcpy_user((to), (from), (n)) |
| 257 | #define __copy_to_user_inatomic(to, from, n) __memcpy_user((to), (from), (n)) |
| 258 | |
| 259 | #else |
| 260 | |
| 261 | #define clear_user(dst,count) (memset((dst), 0, (count)), 0) |
| 262 | #define __copy_from_user_inatomic(to, from, n) (memcpy((to), (from), (n)), 0) |
| 263 | #define __copy_to_user_inatomic(to, from, n) (memcpy((to), (from), (n)), 0) |
| 264 | |
| 265 | #endif |
| 266 | |
| 267 | static inline unsigned long __must_check |
| 268 | __copy_to_user(void __user *to, const void *from, unsigned long n) |
| 269 | { |
| 270 | might_sleep(); |
| 271 | return __copy_to_user_inatomic(to, from, n); |
| 272 | } |
| 273 | |
| 274 | static inline unsigned long |
| 275 | __copy_from_user(void *to, const void __user *from, unsigned long n) |
| 276 | { |
| 277 | might_sleep(); |
| 278 | return __copy_from_user_inatomic(to, from, n); |
| 279 | } |
| 280 | |
| 281 | static inline long copy_from_user(void *to, const void *from, unsigned long n) |
| 282 | { |
| 283 | unsigned long ret = n; |
| 284 | |
| 285 | if (likely(__access_ok(from, n))) |
| 286 | ret = __copy_from_user(to, from, n); |
| 287 | |
| 288 | if (unlikely(ret != 0)) |
| 289 | memset(to + (n - ret), 0, ret); |
| 290 | |
| 291 | return ret; |
| 292 | } |
| 293 | |
| 294 | static inline long copy_to_user(void *to, const void *from, unsigned long n) |
| 295 | { |
| 296 | return likely(__access_ok(to, n)) ? __copy_to_user(to, from, n) : n; |
| 297 | } |
| 298 | |
| 299 | #define copy_to_user_ret(to,from,n,retval) ({ if (copy_to_user(to,from,n)) return retval; }) |
| 300 | #define copy_from_user_ret(to,from,n,retval) ({ if (copy_from_user(to,from,n)) return retval; }) |
| 301 | |
| 302 | extern long strncpy_from_user(char *dst, const char *src, long count); |
| 303 | extern long strnlen_user(const char *src, long count); |
| 304 | |
| 305 | #define strlen_user(str) strnlen_user(str, 32767) |
| 306 | |
| 307 | extern unsigned long search_exception_table(unsigned long addr); |
| 308 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 309 | #endif /* _ASM_UACCESS_H */ |