uaccess_64.h 6.3 KB

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  1. #ifndef _ASM_X86_UACCESS_64_H
  2. #define _ASM_X86_UACCESS_64_H
  3. /*
  4. * User space memory access functions
  5. */
  6. #include <linux/compiler.h>
  7. #include <linux/errno.h>
  8. #include <linux/prefetch.h>
  9. #include <linux/lockdep.h>
  10. #include <asm/page.h>
  11. /*
  12. * Copy To/From Userspace
  13. */
  14. /* Handles exceptions in both to and from, but doesn't do access_ok */
  15. __must_check unsigned long
  16. copy_user_generic(void *to, const void *from, unsigned len);
  17. __must_check unsigned long
  18. _copy_to_user(void __user *to, const void *from, unsigned len);
  19. __must_check unsigned long
  20. _copy_from_user(void *to, const void __user *from, unsigned len);
  21. __must_check unsigned long
  22. copy_in_user(void __user *to, const void __user *from, unsigned len);
  23. static inline unsigned long __must_check copy_from_user(void *to,
  24. const void __user *from,
  25. unsigned long n)
  26. {
  27. int sz = __compiletime_object_size(to);
  28. int ret = -EFAULT;
  29. might_fault();
  30. if (likely(sz == -1 || sz >= n))
  31. ret = _copy_from_user(to, from, n);
  32. #ifdef CONFIG_DEBUG_VM
  33. else
  34. WARN(1, "Buffer overflow detected!\n");
  35. #endif
  36. return ret;
  37. }
  38. static __always_inline __must_check
  39. int copy_to_user(void __user *dst, const void *src, unsigned size)
  40. {
  41. might_fault();
  42. return _copy_to_user(dst, src, size);
  43. }
  44. static __always_inline __must_check
  45. int __copy_from_user(void *dst, const void __user *src, unsigned size)
  46. {
  47. int ret = 0;
  48. might_fault();
  49. if (!__builtin_constant_p(size))
  50. return copy_user_generic(dst, (__force void *)src, size);
  51. switch (size) {
  52. case 1:__get_user_asm(*(u8 *)dst, (u8 __user *)src,
  53. ret, "b", "b", "=q", 1);
  54. return ret;
  55. case 2:__get_user_asm(*(u16 *)dst, (u16 __user *)src,
  56. ret, "w", "w", "=r", 2);
  57. return ret;
  58. case 4:__get_user_asm(*(u32 *)dst, (u32 __user *)src,
  59. ret, "l", "k", "=r", 4);
  60. return ret;
  61. case 8:__get_user_asm(*(u64 *)dst, (u64 __user *)src,
  62. ret, "q", "", "=r", 8);
  63. return ret;
  64. case 10:
  65. __get_user_asm(*(u64 *)dst, (u64 __user *)src,
  66. ret, "q", "", "=r", 10);
  67. if (unlikely(ret))
  68. return ret;
  69. __get_user_asm(*(u16 *)(8 + (char *)dst),
  70. (u16 __user *)(8 + (char __user *)src),
  71. ret, "w", "w", "=r", 2);
  72. return ret;
  73. case 16:
  74. __get_user_asm(*(u64 *)dst, (u64 __user *)src,
  75. ret, "q", "", "=r", 16);
  76. if (unlikely(ret))
  77. return ret;
  78. __get_user_asm(*(u64 *)(8 + (char *)dst),
  79. (u64 __user *)(8 + (char __user *)src),
  80. ret, "q", "", "=r", 8);
  81. return ret;
  82. default:
  83. return copy_user_generic(dst, (__force void *)src, size);
  84. }
  85. }
  86. static __always_inline __must_check
  87. int __copy_to_user(void __user *dst, const void *src, unsigned size)
  88. {
  89. int ret = 0;
  90. might_fault();
  91. if (!__builtin_constant_p(size))
  92. return copy_user_generic((__force void *)dst, src, size);
  93. switch (size) {
  94. case 1:__put_user_asm(*(u8 *)src, (u8 __user *)dst,
  95. ret, "b", "b", "iq", 1);
  96. return ret;
  97. case 2:__put_user_asm(*(u16 *)src, (u16 __user *)dst,
  98. ret, "w", "w", "ir", 2);
  99. return ret;
  100. case 4:__put_user_asm(*(u32 *)src, (u32 __user *)dst,
  101. ret, "l", "k", "ir", 4);
  102. return ret;
  103. case 8:__put_user_asm(*(u64 *)src, (u64 __user *)dst,
  104. ret, "q", "", "er", 8);
  105. return ret;
  106. case 10:
  107. __put_user_asm(*(u64 *)src, (u64 __user *)dst,
  108. ret, "q", "", "er", 10);
  109. if (unlikely(ret))
  110. return ret;
  111. asm("":::"memory");
  112. __put_user_asm(4[(u16 *)src], 4 + (u16 __user *)dst,
  113. ret, "w", "w", "ir", 2);
  114. return ret;
  115. case 16:
  116. __put_user_asm(*(u64 *)src, (u64 __user *)dst,
  117. ret, "q", "", "er", 16);
  118. if (unlikely(ret))
  119. return ret;
  120. asm("":::"memory");
  121. __put_user_asm(1[(u64 *)src], 1 + (u64 __user *)dst,
  122. ret, "q", "", "er", 8);
  123. return ret;
  124. default:
  125. return copy_user_generic((__force void *)dst, src, size);
  126. }
  127. }
  128. static __always_inline __must_check
  129. int __copy_in_user(void __user *dst, const void __user *src, unsigned size)
  130. {
  131. int ret = 0;
  132. might_fault();
  133. if (!__builtin_constant_p(size))
  134. return copy_user_generic((__force void *)dst,
  135. (__force void *)src, size);
  136. switch (size) {
  137. case 1: {
  138. u8 tmp;
  139. __get_user_asm(tmp, (u8 __user *)src,
  140. ret, "b", "b", "=q", 1);
  141. if (likely(!ret))
  142. __put_user_asm(tmp, (u8 __user *)dst,
  143. ret, "b", "b", "iq", 1);
  144. return ret;
  145. }
  146. case 2: {
  147. u16 tmp;
  148. __get_user_asm(tmp, (u16 __user *)src,
  149. ret, "w", "w", "=r", 2);
  150. if (likely(!ret))
  151. __put_user_asm(tmp, (u16 __user *)dst,
  152. ret, "w", "w", "ir", 2);
  153. return ret;
  154. }
  155. case 4: {
  156. u32 tmp;
  157. __get_user_asm(tmp, (u32 __user *)src,
  158. ret, "l", "k", "=r", 4);
  159. if (likely(!ret))
  160. __put_user_asm(tmp, (u32 __user *)dst,
  161. ret, "l", "k", "ir", 4);
  162. return ret;
  163. }
  164. case 8: {
  165. u64 tmp;
  166. __get_user_asm(tmp, (u64 __user *)src,
  167. ret, "q", "", "=r", 8);
  168. if (likely(!ret))
  169. __put_user_asm(tmp, (u64 __user *)dst,
  170. ret, "q", "", "er", 8);
  171. return ret;
  172. }
  173. default:
  174. return copy_user_generic((__force void *)dst,
  175. (__force void *)src, size);
  176. }
  177. }
  178. __must_check long
  179. strncpy_from_user(char *dst, const char __user *src, long count);
  180. __must_check long
  181. __strncpy_from_user(char *dst, const char __user *src, long count);
  182. __must_check long strnlen_user(const char __user *str, long n);
  183. __must_check long __strnlen_user(const char __user *str, long n);
  184. __must_check long strlen_user(const char __user *str);
  185. __must_check unsigned long clear_user(void __user *mem, unsigned long len);
  186. __must_check unsigned long __clear_user(void __user *mem, unsigned long len);
  187. static __must_check __always_inline int
  188. __copy_from_user_inatomic(void *dst, const void __user *src, unsigned size)
  189. {
  190. return copy_user_generic(dst, (__force const void *)src, size);
  191. }
  192. static __must_check __always_inline int
  193. __copy_to_user_inatomic(void __user *dst, const void *src, unsigned size)
  194. {
  195. return copy_user_generic((__force void *)dst, src, size);
  196. }
  197. extern long __copy_user_nocache(void *dst, const void __user *src,
  198. unsigned size, int zerorest);
  199. static inline int
  200. __copy_from_user_nocache(void *dst, const void __user *src, unsigned size)
  201. {
  202. might_sleep();
  203. return __copy_user_nocache(dst, src, size, 1);
  204. }
  205. static inline int
  206. __copy_from_user_inatomic_nocache(void *dst, const void __user *src,
  207. unsigned size)
  208. {
  209. return __copy_user_nocache(dst, src, size, 0);
  210. }
  211. unsigned long
  212. copy_user_handle_tail(char *to, char *from, unsigned len, unsigned zerorest);
  213. #endif /* _ASM_X86_UACCESS_64_H */