uaccess.h 8.1 KB

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  1. /* SPDX-License-Identifier: GPL-2.0 */
  2. #ifndef __ALPHA_UACCESS_H
  3. #define __ALPHA_UACCESS_H
  4. #include <asm-generic/access_ok.h>
  5. /*
  6. * These are the main single-value transfer routines. They automatically
  7. * use the right size if we just have the right pointer type.
  8. *
  9. * As the alpha uses the same address space for kernel and user
  10. * data, we can just do these as direct assignments. (Of course, the
  11. * exception handling means that it's no longer "just"...)
  12. *
  13. * Careful to not
  14. * (a) re-use the arguments for side effects (sizeof/typeof is ok)
  15. * (b) require any knowledge of processes at this stage
  16. */
  17. #define put_user(x, ptr) \
  18. __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
  19. #define get_user(x, ptr) \
  20. __get_user_check((x), (ptr), sizeof(*(ptr)))
  21. /*
  22. * The "__xxx" versions do not do address space checking, useful when
  23. * doing multiple accesses to the same area (the programmer has to do the
  24. * checks by hand with "access_ok()")
  25. */
  26. #define __put_user(x, ptr) \
  27. __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
  28. #define __get_user(x, ptr) \
  29. __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
  30. /*
  31. * The "lda %1, 2b-1b(%0)" bits are magic to get the assembler to
  32. * encode the bits we need for resolving the exception. See the
  33. * more extensive comments with fixup_inline_exception below for
  34. * more information.
  35. */
  36. #define EXC(label,cont,res,err) \
  37. ".section __ex_table,\"a\"\n" \
  38. " .long "#label"-.\n" \
  39. " lda "#res","#cont"-"#label"("#err")\n" \
  40. ".previous\n"
  41. extern void __get_user_unknown(void);
  42. #define __get_user_nocheck(x, ptr, size) \
  43. ({ \
  44. long __gu_err = 0; \
  45. unsigned long __gu_val; \
  46. __chk_user_ptr(ptr); \
  47. switch (size) { \
  48. case 1: __get_user_8(ptr); break; \
  49. case 2: __get_user_16(ptr); break; \
  50. case 4: __get_user_32(ptr); break; \
  51. case 8: __get_user_64(ptr); break; \
  52. default: __get_user_unknown(); break; \
  53. } \
  54. (x) = (__force __typeof__(*(ptr))) __gu_val; \
  55. __gu_err; \
  56. })
  57. #define __get_user_check(x, ptr, size) \
  58. ({ \
  59. long __gu_err = -EFAULT; \
  60. unsigned long __gu_val = 0; \
  61. const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
  62. if (__access_ok(__gu_addr, size)) { \
  63. __gu_err = 0; \
  64. switch (size) { \
  65. case 1: __get_user_8(__gu_addr); break; \
  66. case 2: __get_user_16(__gu_addr); break; \
  67. case 4: __get_user_32(__gu_addr); break; \
  68. case 8: __get_user_64(__gu_addr); break; \
  69. default: __get_user_unknown(); break; \
  70. } \
  71. } \
  72. (x) = (__force __typeof__(*(ptr))) __gu_val; \
  73. __gu_err; \
  74. })
  75. struct __large_struct { unsigned long buf[100]; };
  76. #define __m(x) (*(struct __large_struct __user *)(x))
  77. #define __get_user_64(addr) \
  78. __asm__("1: ldq %0,%2\n" \
  79. "2:\n" \
  80. EXC(1b,2b,%0,%1) \
  81. : "=r"(__gu_val), "=r"(__gu_err) \
  82. : "m"(__m(addr)), "1"(__gu_err))
  83. #define __get_user_32(addr) \
  84. __asm__("1: ldl %0,%2\n" \
  85. "2:\n" \
  86. EXC(1b,2b,%0,%1) \
  87. : "=r"(__gu_val), "=r"(__gu_err) \
  88. : "m"(__m(addr)), "1"(__gu_err))
  89. #ifdef __alpha_bwx__
  90. /* Those lucky bastards with ev56 and later CPUs can do byte/word moves. */
  91. #define __get_user_16(addr) \
  92. __asm__("1: ldwu %0,%2\n" \
  93. "2:\n" \
  94. EXC(1b,2b,%0,%1) \
  95. : "=r"(__gu_val), "=r"(__gu_err) \
  96. : "m"(__m(addr)), "1"(__gu_err))
  97. #define __get_user_8(addr) \
  98. __asm__("1: ldbu %0,%2\n" \
  99. "2:\n" \
  100. EXC(1b,2b,%0,%1) \
  101. : "=r"(__gu_val), "=r"(__gu_err) \
  102. : "m"(__m(addr)), "1"(__gu_err))
  103. #else
  104. /* Unfortunately, we can't get an unaligned access trap for the sub-word
  105. load, so we have to do a general unaligned operation. */
  106. #define __get_user_16(addr) \
  107. { \
  108. long __gu_tmp; \
  109. __asm__("1: ldq_u %0,0(%3)\n" \
  110. "2: ldq_u %1,1(%3)\n" \
  111. " extwl %0,%3,%0\n" \
  112. " extwh %1,%3,%1\n" \
  113. " or %0,%1,%0\n" \
  114. "3:\n" \
  115. EXC(1b,3b,%0,%2) \
  116. EXC(2b,3b,%0,%2) \
  117. : "=&r"(__gu_val), "=&r"(__gu_tmp), "=r"(__gu_err) \
  118. : "r"(addr), "2"(__gu_err)); \
  119. }
  120. #define __get_user_8(addr) \
  121. __asm__("1: ldq_u %0,0(%2)\n" \
  122. " extbl %0,%2,%0\n" \
  123. "2:\n" \
  124. EXC(1b,2b,%0,%1) \
  125. : "=&r"(__gu_val), "=r"(__gu_err) \
  126. : "r"(addr), "1"(__gu_err))
  127. #endif
  128. extern void __put_user_unknown(void);
  129. #define __put_user_nocheck(x, ptr, size) \
  130. ({ \
  131. long __pu_err = 0; \
  132. __chk_user_ptr(ptr); \
  133. switch (size) { \
  134. case 1: __put_user_8(x, ptr); break; \
  135. case 2: __put_user_16(x, ptr); break; \
  136. case 4: __put_user_32(x, ptr); break; \
  137. case 8: __put_user_64(x, ptr); break; \
  138. default: __put_user_unknown(); break; \
  139. } \
  140. __pu_err; \
  141. })
  142. #define __put_user_check(x, ptr, size) \
  143. ({ \
  144. long __pu_err = -EFAULT; \
  145. __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
  146. if (__access_ok(__pu_addr, size)) { \
  147. __pu_err = 0; \
  148. switch (size) { \
  149. case 1: __put_user_8(x, __pu_addr); break; \
  150. case 2: __put_user_16(x, __pu_addr); break; \
  151. case 4: __put_user_32(x, __pu_addr); break; \
  152. case 8: __put_user_64(x, __pu_addr); break; \
  153. default: __put_user_unknown(); break; \
  154. } \
  155. } \
  156. __pu_err; \
  157. })
  158. /*
  159. * The "__put_user_xx()" macros tell gcc they read from memory
  160. * instead of writing: this is because they do not write to
  161. * any memory gcc knows about, so there are no aliasing issues
  162. */
  163. #define __put_user_64(x, addr) \
  164. __asm__ __volatile__("1: stq %r2,%1\n" \
  165. "2:\n" \
  166. EXC(1b,2b,$31,%0) \
  167. : "=r"(__pu_err) \
  168. : "m" (__m(addr)), "rJ" (x), "0"(__pu_err))
  169. #define __put_user_32(x, addr) \
  170. __asm__ __volatile__("1: stl %r2,%1\n" \
  171. "2:\n" \
  172. EXC(1b,2b,$31,%0) \
  173. : "=r"(__pu_err) \
  174. : "m"(__m(addr)), "rJ"(x), "0"(__pu_err))
  175. #ifdef __alpha_bwx__
  176. /* Those lucky bastards with ev56 and later CPUs can do byte/word moves. */
  177. #define __put_user_16(x, addr) \
  178. __asm__ __volatile__("1: stw %r2,%1\n" \
  179. "2:\n" \
  180. EXC(1b,2b,$31,%0) \
  181. : "=r"(__pu_err) \
  182. : "m"(__m(addr)), "rJ"(x), "0"(__pu_err))
  183. #define __put_user_8(x, addr) \
  184. __asm__ __volatile__("1: stb %r2,%1\n" \
  185. "2:\n" \
  186. EXC(1b,2b,$31,%0) \
  187. : "=r"(__pu_err) \
  188. : "m"(__m(addr)), "rJ"(x), "0"(__pu_err))
  189. #else
  190. /* Unfortunately, we can't get an unaligned access trap for the sub-word
  191. write, so we have to do a general unaligned operation. */
  192. #define __put_user_16(x, addr) \
  193. { \
  194. long __pu_tmp1, __pu_tmp2, __pu_tmp3, __pu_tmp4; \
  195. __asm__ __volatile__( \
  196. "1: ldq_u %2,1(%5)\n" \
  197. "2: ldq_u %1,0(%5)\n" \
  198. " inswh %6,%5,%4\n" \
  199. " inswl %6,%5,%3\n" \
  200. " mskwh %2,%5,%2\n" \
  201. " mskwl %1,%5,%1\n" \
  202. " or %2,%4,%2\n" \
  203. " or %1,%3,%1\n" \
  204. "3: stq_u %2,1(%5)\n" \
  205. "4: stq_u %1,0(%5)\n" \
  206. "5:\n" \
  207. EXC(1b,5b,$31,%0) \
  208. EXC(2b,5b,$31,%0) \
  209. EXC(3b,5b,$31,%0) \
  210. EXC(4b,5b,$31,%0) \
  211. : "=r"(__pu_err), "=&r"(__pu_tmp1), \
  212. "=&r"(__pu_tmp2), "=&r"(__pu_tmp3), \
  213. "=&r"(__pu_tmp4) \
  214. : "r"(addr), "r"((unsigned long)(x)), "0"(__pu_err)); \
  215. }
  216. #define __put_user_8(x, addr) \
  217. { \
  218. long __pu_tmp1, __pu_tmp2; \
  219. __asm__ __volatile__( \
  220. "1: ldq_u %1,0(%4)\n" \
  221. " insbl %3,%4,%2\n" \
  222. " mskbl %1,%4,%1\n" \
  223. " or %1,%2,%1\n" \
  224. "2: stq_u %1,0(%4)\n" \
  225. "3:\n" \
  226. EXC(1b,3b,$31,%0) \
  227. EXC(2b,3b,$31,%0) \
  228. : "=r"(__pu_err), \
  229. "=&r"(__pu_tmp1), "=&r"(__pu_tmp2) \
  230. : "r"((unsigned long)(x)), "r"(addr), "0"(__pu_err)); \
  231. }
  232. #endif
  233. /*
  234. * Complex access routines
  235. */
  236. extern long __copy_user(void *to, const void *from, long len);
  237. static inline unsigned long
  238. raw_copy_from_user(void *to, const void __user *from, unsigned long len)
  239. {
  240. return __copy_user(to, (__force const void *)from, len);
  241. }
  242. static inline unsigned long
  243. raw_copy_to_user(void __user *to, const void *from, unsigned long len)
  244. {
  245. return __copy_user((__force void *)to, from, len);
  246. }
  247. extern long __clear_user(void __user *to, long len);
  248. static inline long
  249. clear_user(void __user *to, long len)
  250. {
  251. if (__access_ok(to, len))
  252. len = __clear_user(to, len);
  253. return len;
  254. }
  255. extern long strncpy_from_user(char *dest, const char __user *src, long count);
  256. extern __must_check long strnlen_user(const char __user *str, long n);
  257. #include <asm/extable.h>
  258. #endif /* __ALPHA_UACCESS_H */