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