arch/s390/include/asm/uaccess.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  *  S390 version
   4  *    Copyright IBM Corp. 1999, 2000
   5  *    Author(s): Hartmut Penner (hp@de.ibm.com),
   6  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
   7  *
   8  *  Derived from "include/asm-i386/uaccess.h"
   9  */
  10 #ifndef __S390_UACCESS_H
  11 #define __S390_UACCESS_H
  12
  13 /*
  14  * User space memory access functions
  15  */
  16 #include <asm/processor.h>
  17 #include <asm/ctl_reg.h>
  18 #include <asm/extable.h>
  19 #include <asm/facility.h>
  20
  21 /*
  22  * The fs value determines whether argument validity checking should be
  23  * performed or not.  If get_fs() == USER_DS, checking is performed, with
  24  * get_fs() == KERNEL_DS, checking is bypassed.
  25  *
  26  * For historical reasons, these macros are grossly misnamed.
  27  */
  28
  29 #define KERNEL_DS       (0)
  30 #define KERNEL_DS_SACF  (1)
  31 #define USER_DS         (2)
  32 #define USER_DS_SACF    (3)
  33
  34 #define get_ds()        (KERNEL_DS)
  35 #define get_fs()        (current->thread.mm_segment)
  36 #define segment_eq(a,b) (((a) & 2) == ((b) & 2))
  37
  38 void set_fs(mm_segment_t fs);
  39
  40 static inline int __range_ok(unsigned long addr, unsigned long size)
  41 {
  42         return 1;
  43 }
  44
  45 #define __access_ok(addr, size)                         \
  46 ({                                                      \
  47         __chk_user_ptr(addr);                           \
  48         __range_ok((unsigned long)(addr), (size));      \
  49 })
  50
  51 #define access_ok(addr, size) __access_ok(addr, size)
  52
  53 unsigned long __must_check
  54 raw_copy_from_user(void *to, const void __user *from, unsigned long n);
  55
  56 unsigned long __must_check
  57 raw_copy_to_user(void __user *to, const void *from, unsigned long n);
  58
  59 #define INLINE_COPY_FROM_USER
  60 #define INLINE_COPY_TO_USER
  61
  62 #ifdef CONFIG_HAVE_MARCH_Z10_FEATURES
  63
  64 #define __put_get_user_asm(to, from, size, spec)                \
  65 ({                                                              \
  66         register unsigned long __reg0 asm("0") = spec;          \
  67         int __rc;                                               \
  68                                                                 \
  69         asm volatile(                                           \
  70                 "0:     mvcos   %1,%3,%2\n"                     \
  71                 "1:     xr      %0,%0\n"                        \
  72                 "2:\n"                                          \
  73                 ".pushsection .fixup, \"ax\"\n"                 \
  74                 "3:     lhi     %0,%5\n"                        \
  75                 "       jg      2b\n"                           \
  76                 ".popsection\n"                                 \
  77                 EX_TABLE(0b,3b) EX_TABLE(1b,3b)                 \
  78                 : "=d" (__rc), "+Q" (*(to))                     \
  79                 : "d" (size), "Q" (*(from)),                    \
  80                   "d" (__reg0), "K" (-EFAULT)                   \
  81                 : "cc");                                        \
  82         __rc;                                                   \
  83 })
  84
  85 static inline int __put_user_fn(void *x, void __user *ptr, unsigned long size)
  86 {
  87         unsigned long spec = 0x010000UL;
  88         int rc;
  89
  90         switch (size) {
  91         case 1:
  92                 rc = __put_get_user_asm((unsigned char __user *)ptr,
  93                                         (unsigned char *)x,
  94                                         size, spec);
  95                 break;
  96         case 2:
  97                 rc = __put_get_user_asm((unsigned short __user *)ptr,
  98                                         (unsigned short *)x,
  99                                         size, spec);
 100                 break;
 101         case 4:
 102                 rc = __put_get_user_asm((unsigned int __user *)ptr,
 103                                         (unsigned int *)x,
 104                                         size, spec);
 105                 break;
 106         case 8:
 107                 rc = __put_get_user_asm((unsigned long __user *)ptr,
 108                                         (unsigned long *)x,
 109                                         size, spec);
 110                 break;
 111         }
 112         return rc;
 113 }
 114
 115 static inline int __get_user_fn(void *x, const void __user *ptr, unsigned long size)
 116 {
 117         unsigned long spec = 0x01UL;
 118         int rc;
 119
 120         switch (size) {
 121         case 1:
 122                 rc = __put_get_user_asm((unsigned char *)x,
 123                                         (unsigned char __user *)ptr,
 124                                         size, spec);
 125                 break;
 126         case 2:
 127                 rc = __put_get_user_asm((unsigned short *)x,
 128                                         (unsigned short __user *)ptr,
 129                                         size, spec);
 130                 break;
 131         case 4:
 132                 rc = __put_get_user_asm((unsigned int *)x,
 133                                         (unsigned int __user *)ptr,
 134                                         size, spec);
 135                 break;
 136         case 8:
 137                 rc = __put_get_user_asm((unsigned long *)x,
 138                                         (unsigned long __user *)ptr,
 139                                         size, spec);
 140                 break;
 141         }
 142         return rc;
 143 }
 144
 145 #else /* CONFIG_HAVE_MARCH_Z10_FEATURES */
 146
 147 static inline int __put_user_fn(void *x, void __user *ptr, unsigned long size)
 148 {
 149         size = raw_copy_to_user(ptr, x, size);
 150         return size ? -EFAULT : 0;
 151 }
 152
 153 static inline int __get_user_fn(void *x, const void __user *ptr, unsigned long size)
 154 {
 155         size = raw_copy_from_user(x, ptr, size);
 156         return size ? -EFAULT : 0;
 157 }
 158
 159 #endif /* CONFIG_HAVE_MARCH_Z10_FEATURES */
 160
 161 /*
 162  * These are the main single-value transfer routines.  They automatically
 163  * use the right size if we just have the right pointer type.
 164  */
 165 #define __put_user(x, ptr) \
 166 ({                                                              \
 167         __typeof__(*(ptr)) __x = (x);                           \
 168         int __pu_err = -EFAULT;                                 \
 169         __chk_user_ptr(ptr);                                    \
 170         switch (sizeof (*(ptr))) {                              \
 171         case 1:                                                 \
 172         case 2:                                                 \
 173         case 4:                                                 \
 174         case 8:                                                 \
 175                 __pu_err = __put_user_fn(&__x, ptr,             \
 176                                          sizeof(*(ptr)));       \
 177                 break;                                          \
 178         default:                                                \
 179                 __put_user_bad();                               \
 180                 break;                                          \
 181          }                                                      \
 182         __builtin_expect(__pu_err, 0);                          \
 183 })
 184
 185 #define put_user(x, ptr)                                        \
 186 ({                                                              \
 187         might_fault();                                          \
 188         __put_user(x, ptr);                                     \
 189 })
 190
 191
 192 int __put_user_bad(void) __attribute__((noreturn));
 193
 194 #define __get_user(x, ptr)                                      \
 195 ({                                                              \
 196         int __gu_err = -EFAULT;                                 \
 197         __chk_user_ptr(ptr);                                    \
 198         switch (sizeof(*(ptr))) {                               \
 199         case 1: {                                               \
 200                 unsigned char __x = 0;                          \
 201                 __gu_err = __get_user_fn(&__x, ptr,             \
 202                                          sizeof(*(ptr)));       \
 203                 (x) = *(__force __typeof__(*(ptr)) *) &__x;     \
 204                 break;                                          \
 205         };                                                      \
 206         case 2: {                                               \
 207                 unsigned short __x = 0;                         \
 208                 __gu_err = __get_user_fn(&__x, ptr,             \
 209                                          sizeof(*(ptr)));       \
 210                 (x) = *(__force __typeof__(*(ptr)) *) &__x;     \
 211                 break;                                          \
 212         };                                                      \
 213         case 4: {                                               \
 214                 unsigned int __x = 0;                           \
 215                 __gu_err = __get_user_fn(&__x, ptr,             \
 216                                          sizeof(*(ptr)));       \
 217                 (x) = *(__force __typeof__(*(ptr)) *) &__x;     \
 218                 break;                                          \
 219         };                                                      \
 220         case 8: {                                               \
 221                 unsigned long long __x = 0;                     \
 222                 __gu_err = __get_user_fn(&__x, ptr,             \
 223                                          sizeof(*(ptr)));       \
 224                 (x) = *(__force __typeof__(*(ptr)) *) &__x;     \
 225                 break;                                          \
 226         };                                                      \
 227         default:                                                \
 228                 __get_user_bad();                               \
 229                 break;                                          \
 230         }                                                       \
 231         __builtin_expect(__gu_err, 0);                          \
 232 })
 233
 234 #define get_user(x, ptr)                                        \
 235 ({                                                              \
 236         might_fault();                                          \
 237         __get_user(x, ptr);                                     \
 238 })
 239
 240 int __get_user_bad(void) __attribute__((noreturn));
 241
 242 unsigned long __must_check
 243 raw_copy_in_user(void __user *to, const void __user *from, unsigned long n);
 244
 245 /*
 246  * Copy a null terminated string from userspace.
 247  */
 248
 249 long __strncpy_from_user(char *dst, const char __user *src, long count);
 250
 251 static inline long __must_check
 252 strncpy_from_user(char *dst, const char __user *src, long count)
 253 {
 254         might_fault();
 255         return __strncpy_from_user(dst, src, count);
 256 }
 257
 258 unsigned long __must_check __strnlen_user(const char __user *src, unsigned long count);
 259
 260 static inline unsigned long strnlen_user(const char __user *src, unsigned long n)
 261 {
 262         might_fault();
 263         return __strnlen_user(src, n);
 264 }
 265
 266 /*
 267  * Zero Userspace
 268  */
 269 unsigned long __must_check __clear_user(void __user *to, unsigned long size);
 270
 271 static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
 272 {
 273         might_fault();
 274         return __clear_user(to, n);
 275 }
 276
 277 int copy_to_user_real(void __user *dest, void *src, unsigned long count);
 278 void s390_kernel_write(void *dst, const void *src, size_t size);
 279
 280 #endif /* __S390_UACCESS_H */