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 uaccess_kernel() ((get_fs() & 2) == KERNEL_DS)
  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 #ifndef CONFIG_KASAN
  59 #define INLINE_COPY_FROM_USER
  60 #define INLINE_COPY_TO_USER
  61 #endif
  62
  63 #ifdef CONFIG_HAVE_MARCH_Z10_FEATURES
  64
  65 #define __put_get_user_asm(to, from, size, spec)                \
  66 ({                                                              \
  67         register unsigned long __reg0 asm("0") = spec;          \
  68         int __rc;                                               \
  69                                                                 \
  70         asm volatile(                                           \
  71                 "0:     mvcos   %1,%3,%2\n"                     \
  72                 "1:     xr      %0,%0\n"                        \
  73                 "2:\n"                                          \
  74                 ".pushsection .fixup, \"ax\"\n"                 \
  75                 "3:     lhi     %0,%5\n"                        \
  76                 "       jg      2b\n"                           \
  77                 ".popsection\n"                                 \
  78                 EX_TABLE(0b,3b) EX_TABLE(1b,3b)                 \
  79                 : "=d" (__rc), "+Q" (*(to))                     \
  80                 : "d" (size), "Q" (*(from)),                    \
  81                   "d" (__reg0), "K" (-EFAULT)                   \
  82                 : "cc");                                        \
  83         __rc;                                                   \
  84 })
  85
  86 static __always_inline int __put_user_fn(void *x, void __user *ptr, unsigned long size)
  87 {
  88         unsigned long spec = 0x010000UL;
  89         int rc;
  90
  91         switch (size) {
  92         case 1:
  93                 rc = __put_get_user_asm((unsigned char __user *)ptr,
  94                                         (unsigned char *)x,
  95                                         size, spec);
  96                 break;
  97         case 2:
  98                 rc = __put_get_user_asm((unsigned short __user *)ptr,
  99                                         (unsigned short *)x,
 100                                         size, spec);
 101                 break;
 102         case 4:
 103                 rc = __put_get_user_asm((unsigned int __user *)ptr,
 104                                         (unsigned int *)x,
 105                                         size, spec);
 106                 break;
 107         case 8:
 108                 rc = __put_get_user_asm((unsigned long __user *)ptr,
 109                                         (unsigned long *)x,
 110                                         size, spec);
 111                 break;
 112         }
 113         return rc;
 114 }
 115
 116 static __always_inline int __get_user_fn(void *x, const void __user *ptr, unsigned long size)
 117 {
 118         unsigned long spec = 0x01UL;
 119         int rc;
 120
 121         switch (size) {
 122         case 1:
 123                 rc = __put_get_user_asm((unsigned char *)x,
 124                                         (unsigned char __user *)ptr,
 125                                         size, spec);
 126                 break;
 127         case 2:
 128                 rc = __put_get_user_asm((unsigned short *)x,
 129                                         (unsigned short __user *)ptr,
 130                                         size, spec);
 131                 break;
 132         case 4:
 133                 rc = __put_get_user_asm((unsigned int *)x,
 134                                         (unsigned int __user *)ptr,
 135                                         size, spec);
 136                 break;
 137         case 8:
 138                 rc = __put_get_user_asm((unsigned long *)x,
 139                                         (unsigned long __user *)ptr,
 140                                         size, spec);
 141                 break;
 142         }
 143         return rc;
 144 }
 145
 146 #else /* CONFIG_HAVE_MARCH_Z10_FEATURES */
 147
 148 static inline int __put_user_fn(void *x, void __user *ptr, unsigned long size)
 149 {
 150         size = raw_copy_to_user(ptr, x, size);
 151         return size ? -EFAULT : 0;
 152 }
 153
 154 static inline int __get_user_fn(void *x, const void __user *ptr, unsigned long size)
 155 {
 156         size = raw_copy_from_user(x, ptr, size);
 157         return size ? -EFAULT : 0;
 158 }
 159
 160 #endif /* CONFIG_HAVE_MARCH_Z10_FEATURES */
 161
 162 /*
 163  * These are the main single-value transfer routines.  They automatically
 164  * use the right size if we just have the right pointer type.
 165  */
 166 #define __put_user(x, ptr) \
 167 ({                                                              \
 168         __typeof__(*(ptr)) __x = (x);                           \
 169         int __pu_err = -EFAULT;                                 \
 170         __chk_user_ptr(ptr);                                    \
 171         switch (sizeof (*(ptr))) {                              \
 172         case 1:                                                 \
 173         case 2:                                                 \
 174         case 4:                                                 \
 175         case 8:                                                 \
 176                 __pu_err = __put_user_fn(&__x, ptr,             \
 177                                          sizeof(*(ptr)));       \
 178                 break;                                          \
 179         default:                                                \
 180                 __put_user_bad();                               \
 181                 break;                                          \
 182          }                                                      \
 183         __builtin_expect(__pu_err, 0);                          \
 184 })
 185
 186 #define put_user(x, ptr)                                        \
 187 ({                                                              \
 188         might_fault();                                          \
 189         __put_user(x, ptr);                                     \
 190 })
 191
 192
 193 int __put_user_bad(void) __attribute__((noreturn));
 194
 195 #define __get_user(x, ptr)                                      \
 196 ({                                                              \
 197         int __gu_err = -EFAULT;                                 \
 198         __chk_user_ptr(ptr);                                    \
 199         switch (sizeof(*(ptr))) {                               \
 200         case 1: {                                               \
 201                 unsigned char __x = 0;                          \
 202                 __gu_err = __get_user_fn(&__x, ptr,             \
 203                                          sizeof(*(ptr)));       \
 204                 (x) = *(__force __typeof__(*(ptr)) *) &__x;     \
 205                 break;                                          \
 206         };                                                      \
 207         case 2: {                                               \
 208                 unsigned short __x = 0;                         \
 209                 __gu_err = __get_user_fn(&__x, ptr,             \
 210                                          sizeof(*(ptr)));       \
 211                 (x) = *(__force __typeof__(*(ptr)) *) &__x;     \
 212                 break;                                          \
 213         };                                                      \
 214         case 4: {                                               \
 215                 unsigned int __x = 0;                           \
 216                 __gu_err = __get_user_fn(&__x, ptr,             \
 217                                          sizeof(*(ptr)));       \
 218                 (x) = *(__force __typeof__(*(ptr)) *) &__x;     \
 219                 break;                                          \
 220         };                                                      \
 221         case 8: {                                               \
 222                 unsigned long long __x = 0;                     \
 223                 __gu_err = __get_user_fn(&__x, ptr,             \
 224                                          sizeof(*(ptr)));       \
 225                 (x) = *(__force __typeof__(*(ptr)) *) &__x;     \
 226                 break;                                          \
 227         };                                                      \
 228         default:                                                \
 229                 __get_user_bad();                               \
 230                 break;                                          \
 231         }                                                       \
 232         __builtin_expect(__gu_err, 0);                          \
 233 })
 234
 235 #define get_user(x, ptr)                                        \
 236 ({                                                              \
 237         might_fault();                                          \
 238         __get_user(x, ptr);                                     \
 239 })
 240
 241 int __get_user_bad(void) __attribute__((noreturn));
 242
 243 unsigned long __must_check
 244 raw_copy_in_user(void __user *to, const void __user *from, unsigned long n);
 245
 246 /*
 247  * Copy a null terminated string from userspace.
 248  */
 249
 250 long __strncpy_from_user(char *dst, const char __user *src, long count);
 251
 252 static inline long __must_check
 253 strncpy_from_user(char *dst, const char __user *src, long count)
 254 {
 255         might_fault();
 256         return __strncpy_from_user(dst, src, count);
 257 }
 258
 259 unsigned long __must_check __strnlen_user(const char __user *src, unsigned long count);
 260
 261 static inline unsigned long strnlen_user(const char __user *src, unsigned long n)
 262 {
 263         might_fault();
 264         return __strnlen_user(src, n);
 265 }
 266
 267 /*
 268  * Zero Userspace
 269  */
 270 unsigned long __must_check __clear_user(void __user *to, unsigned long size);
 271
 272 static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
 273 {
 274         might_fault();
 275         return __clear_user(to, n);
 276 }
 277
 278 int copy_to_user_real(void __user *dest, void *src, unsigned long count);
 279 void *s390_kernel_write(void *dst, const void *src, size_t size);
 280
 281 #endif /* __S390_UACCESS_H */