rtuDataOperation.h 8.0 KB

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  1. #ifndef _ASM_IA64_UACCESS_H
  2. #define _ASM_IA64_UACCESS_H
  3. /*
  4. * This file defines various macros to transfer memory areas across
  5. * the user/kernel boundary. This needs to be done carefully because
  6. * this code is executed in kernel mode and uses user-specified
  7. * addresses. Thus, we need to be careful not to let the user to
  8. * trick us into accessing kernel memory that would normally be
  9. * inaccessible. This code is also fairly performance sensitive,
  10. * so we want to spend as little time doing safety checks as
  11. * possible.
  12. *
  13. * To make matters a bit more interesting, these macros sometimes also
  14. * called from within the kernel itself, in which case the address
  15. * validity check must be skipped. The get_fs() macro tells us what
  16. * to do: if get_fs()==USER_DS, checking is performed, if
  17. * get_fs()==KERNEL_DS, checking is bypassed.
  18. *
  19. * Note that even if the memory area specified by the user is in a
  20. * valid address range, it is still possible that we'll get a page
  21. * fault while accessing it. This is handled by filling out an
  22. * exception handler fixup entry for each instruction that has the
  23. * potential to fault. When such a fault occurs, the page fault
  24. * handler checks to see whether the faulting instruction has a fixup
  25. * associated and, if so, sets r8 to -EFAULT and clears r9 to 0 and
  26. * then resumes execution at the continuation point.
  27. *
  28. * Based on <asm-alpha/uaccess.h>.
  29. *
  30. * Copyright (C) 1998, 1999, 2001-2004 Hewlett-Packard Co
  31. * David Mosberger-Tang <davidm@hpl.hp.com>
  32. */
  33. #include <linux/compiler.h>
  34. #include <linux/errno.h>
  35. #include <linux/sched.h>
  36. #include <linux/page-flags.h>
  37. #include <linux/mm.h>
  38. #include <asm/intrinsics.h>
  39. #include <asm/pgtable.h>
  40. #include <asm/io.h>
  41. /*
  42. * For historical reasons, the following macros are grossly misnamed:
  43. */
  44. #define KERNEL_DS ((mm_segment_t) { ~0UL }) /* cf. access_ok() */
  45. #define USER_DS ((mm_segment_t) { TASK_SIZE-1 }) /* cf. access_ok() */
  46. #define VERIFY_READ 0
  47. #define VERIFY_WRITE 1
  48. #define get_ds() (KERNEL_DS)
  49. #define get_fs() (current_thread_info()->addr_limit)
  50. #define set_fs(x) (current_thread_info()->addr_limit = (x))
  51. #define segment_eq(a, b) ((a).seg == (b).seg)
  52. /*
  53. * When accessing user memory, we need to make sure the entire area really is in
  54. * user-level space. In order to do this efficiently, we make sure that the page at
  55. * address TASK_SIZE is never valid. We also need to make sure that the address doesn't
  56. * point inside the virtually mapped linear page table.
  57. */
  58. #define __access_ok(addr, size, segment) \
  59. ({ \
  60. __chk_user_ptr(addr); \
  61. (likely((unsigned long) (addr) <= (segment).seg) \
  62. && ((segment).seg == KERNEL_DS.seg \
  63. || likely(REGION_OFFSET((unsigned long) (addr)) < RGN_MAP_LIMIT))); \
  64. })
  65. #define access_ok(type, addr, size) __access_ok((addr), (size), get_fs())
  66. /*
  67. * These are the main single-value transfer routines. They automatically
  68. * use the right size if we just have the right pointer type.
  69. *
  70. * Careful to not
  71. * (a) re-use the arguments for side effects (sizeof/typeof is ok)
  72. * (b) require any knowledge of processes at this stage
  73. */
  74. #define put_user(x, ptr) __put_user_check((__typeof__(*(ptr))) (x), (ptr), sizeof(*(ptr)), get_fs())
  75. #define get_user(x, ptr) __get_user_check((x), (ptr), sizeof(*(ptr)), get_fs())
  76. /*
  77. * The "__xxx" versions do not do address space checking, useful when
  78. * doing multiple accesses to the same area (the programmer has to do the
  79. * checks by hand with "access_ok()")
  80. */
  81. #define __put_user(x, ptr) __put_user_nocheck((__typeof__(*(ptr))) (x), (ptr), sizeof(*(ptr)))
  82. #define __get_user(x, ptr) __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
  83. extern long __put_user_unaligned_unknown (void);
  84. #define __put_user_unaligned(x, ptr) \
  85. ({ \
  86. long __ret; \
  87. switch (sizeof(*(ptr))) { \
  88. case 1: __ret = __put_user((x), (ptr)); break; \
  89. case 2: __ret = (__put_user((x), (u8 __user *)(ptr))) \
  90. | (__put_user((x) >> 8, ((u8 __user *)(ptr) + 1))); break; \
  91. case 4: __ret = (__put_user((x), (u16 __user *)(ptr))) \
  92. | (__put_user((x) >> 16, ((u16 __user *)(ptr) + 1))); break; \
  93. case 8: __ret = (__put_user((x), (u32 __user *)(ptr))) \
  94. | (__put_user((x) >> 32, ((u32 __user *)(ptr) + 1))); break; \
  95. default: __ret = __put_user_unaligned_unknown(); \
  96. } \
  97. __ret; \
  98. })
  99. extern long __get_user_unaligned_unknown (void);
  100. #define __get_user_unaligned(x, ptr) \
  101. ({ \
  102. long __ret; \
  103. switch (sizeof(*(ptr))) { \
  104. case 1: __ret = __get_user((x), (ptr)); break; \
  105. case 2: __ret = (__get_user((x), (u8 __user *)(ptr))) \
  106. | (__get_user((x) >> 8, ((u8 __user *)(ptr) + 1))); break; \
  107. case 4: __ret = (__get_user((x), (u16 __user *)(ptr))) \
  108. | (__get_user((x) >> 16, ((u16 __user *)(ptr) + 1))); break; \
  109. case 8: __ret = (__get_user((x), (u32 __user *)(ptr))) \
  110. | (__get_user((x) >> 32, ((u32 __user *)(ptr) + 1))); break; \
  111. default: __ret = __get_user_unaligned_unknown(); \
  112. } \
  113. __ret; \
  114. })
  115. #ifdef ASM_SUPPORTED
  116. struct __large_struct { unsigned long buf[100]; };
  117. # define __m(x) (*(struct __large_struct __user *)(x))
  118. /* We need to declare the __ex_table section before we can use it in .xdata. */
  119. asm (".section \"__ex_table\", \"a\"\n\t.previous");
  120. # define __get_user_size(val, addr, n, err) \
  121. do { \
  122. register long __gu_r8 asm ("r8") = 0; \
  123. register long __gu_r9 asm ("r9"); \
  124. asm ("\n[1:]\tld"#n" %0=%2%P2\t// %0 and %1 get overwritten by exception handler\n" \
  125. "\t.xdata4 \"__ex_table\", 1b-., 1f-.+4\n" \
  126. "[1:]" \
  127. : "=r"(__gu_r9), "=r"(__gu_r8) : "m"(__m(addr)), "1"(__gu_r8)); \
  128. (err) = __gu_r8; \
  129. (val) = __gu_r9; \
  130. } while (0)
  131. /*
  132. * The "__put_user_size()" macro tells gcc it reads from memory instead of writing it. This
  133. * is because they do not write to any memory gcc knows about, so there are no aliasing
  134. * issues.
  135. */
  136. # define __put_user_size(val, addr, n, err) \
  137. do { \
  138. register long __pu_r8 asm ("r8") = 0; \
  139. asm volatile ("\n[1:]\tst"#n" %1=%r2%P1\t// %0 gets overwritten by exception handler\n" \
  140. "\t.xdata4 \"__ex_table\", 1b-., 1f-.\n" \
  141. "[1:]" \
  142. : "=r"(__pu_r8) : "m"(__m(addr)), "rO"(val), "0"(__pu_r8)); \
  143. (err) = __pu_r8; \
  144. } while (0)
  145. #else /* !ASM_SUPPORTED */
  146. # define RELOC_TYPE 2 /* ip-rel */
  147. # define __get_user_size(val, addr, n, err) \
  148. do { \
  149. __ld_user("__ex_table", (unsigned long) addr, n, RELOC_TYPE); \
  150. (err) = ia64_getreg(_IA64_REG_R8); \
  151. (val) = ia64_getreg(_IA64_REG_R9); \
  152. } while (0)
  153. # define __put_user_size(val, addr, n, err) \
  154. do { \
  155. __st_user("__ex_table", (unsigned long) addr, n, RELOC_TYPE, (unsigned long) (val)); \
  156. (err) = ia64_getreg(_IA64_REG_R8); \
  157. } while (0)
  158. #endif /* !ASM_SUPPORTED */
  159. extern void __get_user_unknown (void);
  160. /*
  161. * Evaluating arguments X, PTR, SIZE, and SEGMENT may involve subroutine-calls, which
  162. * could clobber r8 and r9 (among others). Thus, be careful not to evaluate it while
  163. * using r8/r9.
  164. */
  165. #define __do_get_user(check, x, ptr, size, segment) \
  166. ({ \
  167. const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \
  168. __typeof__ (size) __gu_size = (size); \
  169. long __gu_err = -EFAULT; \
  170. unsigned long __gu_val = 0; \
  171. if (!check || __access_ok(__gu_ptr, size, segment)) \
  172. switch (__gu_size) { \
  173. case 1: __get_user_size(__gu_val, __gu_ptr, 1, __gu_err); break; \
  174. case 2: __get_user_size(__gu_val, __gu_ptr, 2, __gu_err); break; \
  175. case 4: __get_user_size(__gu_val, __gu_ptr, 4, __gu_err); break; \
  176. case 8: __get_user_size(__gu_val, __gu_ptr, 8, __gu_err); break; \
  177. default: __get_user_unknown(); break; \
  178. } \
  179. (x) = (__typeof__(*(__gu_ptr))) __gu_val; \
  180. __gu_err; \
  181. })
  182. #define __get_user_nocheck(x, ptr, size) __do_get_user(0, x, ptr, size, KERNEL_DS)
  183. #define __get_user_check(x, ptr, size, segment) __do_get_user(1, x, ptr, size, segment)
  184. extern void __put_user_unknown (void);