1/* 2 * S390 version 3 * Copyright IBM Corp. 1999, 2000 4 * Author(s): Hartmut Penner (hp@de.ibm.com), 5 * Martin Schwidefsky (schwidefsky@de.ibm.com) 6 * 7 * Derived from "include/asm-i386/uaccess.h" 8 */ 9#ifndef __S390_UACCESS_H 10#define __S390_UACCESS_H 11 12/* 13 * User space memory access functions 14 */ 15#include <linux/sched.h> 16#include <linux/errno.h> 17#include <asm/ctl_reg.h> 18 19#define VERIFY_READ 0 20#define VERIFY_WRITE 1 21 22 23/* 24 * The fs value determines whether argument validity checking should be 25 * performed or not. If get_fs() == USER_DS, checking is performed, with 26 * get_fs() == KERNEL_DS, checking is bypassed. 27 * 28 * For historical reasons, these macros are grossly misnamed. 29 */ 30 31#define MAKE_MM_SEG(a) ((mm_segment_t) { (a) }) 32 33 34#define KERNEL_DS MAKE_MM_SEG(0) 35#define USER_DS MAKE_MM_SEG(1) 36 37#define get_ds() (KERNEL_DS) 38#define get_fs() (current->thread.mm_segment) 39 40#define set_fs(x) \ 41({ \ 42 unsigned long __pto; \ 43 current->thread.mm_segment = (x); \ 44 __pto = current->thread.mm_segment.ar4 ? \ 45 S390_lowcore.user_asce : S390_lowcore.kernel_asce; \ 46 __ctl_load(__pto, 7, 7); \ 47}) 48 49#define segment_eq(a,b) ((a).ar4 == (b).ar4) 50 51static inline int __range_ok(unsigned long addr, unsigned long size) 52{ 53 return 1; 54} 55 56#define __access_ok(addr, size) \ 57({ \ 58 __chk_user_ptr(addr); \ 59 __range_ok((unsigned long)(addr), (size)); \ 60}) 61 62#define access_ok(type, addr, size) __access_ok(addr, size) 63 64/* 65 * The exception table consists of pairs of addresses: the first is the 66 * address of an instruction that is allowed to fault, and the second is 67 * the address at which the program should continue. No registers are 68 * modified, so it is entirely up to the continuation code to figure out 69 * what to do. 70 * 71 * All the routines below use bits of fixup code that are out of line 72 * with the main instruction path. This means when everything is well, 73 * we don't even have to jump over them. Further, they do not intrude 74 * on our cache or tlb entries. 75 */ 76 77struct exception_table_entry 78{ 79 int insn, fixup; 80}; 81 82static inline unsigned long extable_insn(const struct exception_table_entry *x) 83{ 84 return (unsigned long)&x->insn + x->insn; 85} 86 87static inline unsigned long extable_fixup(const struct exception_table_entry *x) 88{ 89 return (unsigned long)&x->fixup + x->fixup; 90} 91 92#define ARCH_HAS_SORT_EXTABLE 93#define ARCH_HAS_SEARCH_EXTABLE 94 95/** 96 * __copy_from_user: - Copy a block of data from user space, with less checking. 97 * @to: Destination address, in kernel space. 98 * @from: Source address, in user space. 99 * @n: Number of bytes to copy. 100 * 101 * Context: User context only. This function may sleep. 102 * 103 * Copy data from user space to kernel space. Caller must check 104 * the specified block with access_ok() before calling this function. 105 * 106 * Returns number of bytes that could not be copied. 107 * On success, this will be zero. 108 * 109 * If some data could not be copied, this function will pad the copied 110 * data to the requested size using zero bytes. 111 */ 112unsigned long __must_check __copy_from_user(void *to, const void __user *from, 113 unsigned long n); 114 115/** 116 * __copy_to_user: - Copy a block of data into user space, with less checking. 117 * @to: Destination address, in user space. 118 * @from: Source address, in kernel space. 119 * @n: Number of bytes to copy. 120 * 121 * Context: User context only. This function may sleep. 122 * 123 * Copy data from kernel space to user space. Caller must check 124 * the specified block with access_ok() before calling this function. 125 * 126 * Returns number of bytes that could not be copied. 127 * On success, this will be zero. 128 */ 129unsigned long __must_check __copy_to_user(void __user *to, const void *from, 130 unsigned long n); 131 132#define __copy_to_user_inatomic __copy_to_user 133#define __copy_from_user_inatomic __copy_from_user 134 135#ifdef CONFIG_HAVE_MARCH_Z10_FEATURES 136 137#define __put_get_user_asm(to, from, size, spec) \ 138({ \ 139 register unsigned long __reg0 asm("0") = spec; \ 140 int __rc; \ 141 \ 142 asm volatile( \ 143 "0: mvcos %1,%3,%2\n" \ 144 "1: xr %0,%0\n" \ 145 "2:\n" \ 146 ".pushsection .fixup, \"ax\"\n" \ 147 "3: lhi %0,%5\n" \ 148 " jg 2b\n" \ 149 ".popsection\n" \ 150 EX_TABLE(0b,3b) EX_TABLE(1b,3b) \ 151 : "=d" (__rc), "=Q" (*(to)) \ 152 : "d" (size), "Q" (*(from)), \ 153 "d" (__reg0), "K" (-EFAULT) \ 154 : "cc"); \ 155 __rc; \ 156}) 157 158#define __put_user_fn(x, ptr, size) __put_get_user_asm(ptr, x, size, 0x810000UL) 159#define __get_user_fn(x, ptr, size) __put_get_user_asm(x, ptr, size, 0x81UL) 160 161#else /* CONFIG_HAVE_MARCH_Z10_FEATURES */ 162 163static inline int __put_user_fn(void *x, void __user *ptr, unsigned long size) 164{ 165 size = __copy_to_user(ptr, x, size); 166 return size ? -EFAULT : 0; 167} 168 169static inline int __get_user_fn(void *x, const void __user *ptr, unsigned long size) 170{ 171 size = __copy_from_user(x, ptr, size); 172 return size ? -EFAULT : 0; 173} 174 175#endif /* CONFIG_HAVE_MARCH_Z10_FEATURES */ 176 177/* 178 * These are the main single-value transfer routines. They automatically 179 * use the right size if we just have the right pointer type. 180 */ 181#define __put_user(x, ptr) \ 182({ \ 183 __typeof__(*(ptr)) __x = (x); \ 184 int __pu_err = -EFAULT; \ 185 __chk_user_ptr(ptr); \ 186 switch (sizeof (*(ptr))) { \ 187 case 1: \ 188 case 2: \ 189 case 4: \ 190 case 8: \ 191 __pu_err = __put_user_fn(&__x, ptr, \ 192 sizeof(*(ptr))); \ 193 break; \ 194 default: \ 195 __put_user_bad(); \ 196 break; \ 197 } \ 198 __pu_err; \ 199}) 200 201#define put_user(x, ptr) \ 202({ \ 203 might_fault(); \ 204 __put_user(x, ptr); \ 205}) 206 207 208int __put_user_bad(void) __attribute__((noreturn)); 209 210#define __get_user(x, ptr) \ 211({ \ 212 int __gu_err = -EFAULT; \ 213 __chk_user_ptr(ptr); \ 214 switch (sizeof(*(ptr))) { \ 215 case 1: { \ 216 unsigned char __x; \ 217 __gu_err = __get_user_fn(&__x, ptr, \ 218 sizeof(*(ptr))); \ 219 (x) = *(__force __typeof__(*(ptr)) *) &__x; \ 220 break; \ 221 }; \ 222 case 2: { \ 223 unsigned short __x; \ 224 __gu_err = __get_user_fn(&__x, ptr, \ 225 sizeof(*(ptr))); \ 226 (x) = *(__force __typeof__(*(ptr)) *) &__x; \ 227 break; \ 228 }; \ 229 case 4: { \ 230 unsigned int __x; \ 231 __gu_err = __get_user_fn(&__x, ptr, \ 232 sizeof(*(ptr))); \ 233 (x) = *(__force __typeof__(*(ptr)) *) &__x; \ 234 break; \ 235 }; \ 236 case 8: { \ 237 unsigned long long __x; \ 238 __gu_err = __get_user_fn(&__x, ptr, \ 239 sizeof(*(ptr))); \ 240 (x) = *(__force __typeof__(*(ptr)) *) &__x; \ 241 break; \ 242 }; \ 243 default: \ 244 __get_user_bad(); \ 245 break; \ 246 } \ 247 __gu_err; \ 248}) 249 250#define get_user(x, ptr) \ 251({ \ 252 might_fault(); \ 253 __get_user(x, ptr); \ 254}) 255 256int __get_user_bad(void) __attribute__((noreturn)); 257 258#define __put_user_unaligned __put_user 259#define __get_user_unaligned __get_user 260 261/** 262 * copy_to_user: - Copy a block of data into user space. 263 * @to: Destination address, in user space. 264 * @from: Source address, in kernel space. 265 * @n: Number of bytes to copy. 266 * 267 * Context: User context only. This function may sleep. 268 * 269 * Copy data from kernel space to user space. 270 * 271 * Returns number of bytes that could not be copied. 272 * On success, this will be zero. 273 */ 274static inline unsigned long __must_check 275copy_to_user(void __user *to, const void *from, unsigned long n) 276{ 277 might_fault(); 278 return __copy_to_user(to, from, n); 279} 280 281void copy_from_user_overflow(void) 282#ifdef CONFIG_DEBUG_STRICT_USER_COPY_CHECKS 283__compiletime_warning("copy_from_user() buffer size is not provably correct") 284#endif 285; 286 287/** 288 * copy_from_user: - Copy a block of data from user space. 289 * @to: Destination address, in kernel space. 290 * @from: Source address, in user space. 291 * @n: Number of bytes to copy. 292 * 293 * Context: User context only. This function may sleep. 294 * 295 * Copy data from user space to kernel space. 296 * 297 * Returns number of bytes that could not be copied. 298 * On success, this will be zero. 299 * 300 * If some data could not be copied, this function will pad the copied 301 * data to the requested size using zero bytes. 302 */ 303static inline unsigned long __must_check 304copy_from_user(void *to, const void __user *from, unsigned long n) 305{ 306 unsigned int sz = __compiletime_object_size(to); 307 308 might_fault(); 309 if (unlikely(sz != -1 && sz < n)) { 310 copy_from_user_overflow(); 311 return n; 312 } 313 return __copy_from_user(to, from, n); 314} 315 316unsigned long __must_check 317__copy_in_user(void __user *to, const void __user *from, unsigned long n); 318 319static inline unsigned long __must_check 320copy_in_user(void __user *to, const void __user *from, unsigned long n) 321{ 322 might_fault(); 323 return __copy_in_user(to, from, n); 324} 325 326/* 327 * Copy a null terminated string from userspace. 328 */ 329 330long __strncpy_from_user(char *dst, const char __user *src, long count); 331 332static inline long __must_check 333strncpy_from_user(char *dst, const char __user *src, long count) 334{ 335 might_fault(); 336 return __strncpy_from_user(dst, src, count); 337} 338 339unsigned long __must_check __strnlen_user(const char __user *src, unsigned long count); 340 341static inline unsigned long strnlen_user(const char __user *src, unsigned long n) 342{ 343 might_fault(); 344 return __strnlen_user(src, n); 345} 346 347/** 348 * strlen_user: - Get the size of a string in user space. 349 * @str: The string to measure. 350 * 351 * Context: User context only. This function may sleep. 352 * 353 * Get the size of a NUL-terminated string in user space. 354 * 355 * Returns the size of the string INCLUDING the terminating NUL. 356 * On exception, returns 0. 357 * 358 * If there is a limit on the length of a valid string, you may wish to 359 * consider using strnlen_user() instead. 360 */ 361#define strlen_user(str) strnlen_user(str, ~0UL) 362 363/* 364 * Zero Userspace 365 */ 366unsigned long __must_check __clear_user(void __user *to, unsigned long size); 367 368static inline unsigned long __must_check clear_user(void __user *to, unsigned long n) 369{ 370 might_fault(); 371 return __clear_user(to, n); 372} 373 374int copy_to_user_real(void __user *dest, void *src, unsigned long count); 375void s390_kernel_write(void *dst, const void *src, size_t size); 376 377#endif /* __S390_UACCESS_H */ 378