getuser.S 3.1 KB

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  1. /*
  2. * linux/arch/arm/lib/getuser.S
  3. *
  4. * Copyright (C) 2001 Russell King
  5. *
  6. * This program is free software; you can redistribute it and/or modify
  7. * it under the terms of the GNU General Public License version 2 as
  8. * published by the Free Software Foundation.
  9. *
  10. * Idea from x86 version, (C) Copyright 1998 Linus Torvalds
  11. *
  12. * These functions have a non-standard call interface to make them more
  13. * efficient, especially as they return an error value in addition to
  14. * the "real" return value.
  15. *
  16. * __get_user_X
  17. *
  18. * Inputs: r0 contains the address
  19. * r1 contains the address limit, which must be preserved
  20. * Outputs: r0 is the error code
  21. * r2, r3 contains the zero-extended value
  22. * lr corrupted
  23. *
  24. * No other registers must be altered. (see <asm/uaccess.h>
  25. * for specific ASM register usage).
  26. *
  27. * Note that ADDR_LIMIT is either 0 or 0xc0000000.
  28. * Note also that it is intended that __get_user_bad is not global.
  29. */
  30. #include <linux/linkage.h>
  31. #include <asm/assembler.h>
  32. #include <asm/errno.h>
  33. #include <asm/domain.h>
  34. ENTRY(__get_user_1)
  35. check_uaccess r0, 1, r1, r2, __get_user_bad
  36. 1: TUSER(ldrb) r2, [r0]
  37. mov r0, #0
  38. ret lr
  39. ENDPROC(__get_user_1)
  40. ENTRY(__get_user_2)
  41. check_uaccess r0, 2, r1, r2, __get_user_bad
  42. #ifdef CONFIG_CPU_USE_DOMAINS
  43. rb .req ip
  44. 2: ldrbt r2, [r0], #1
  45. 3: ldrbt rb, [r0], #0
  46. #else
  47. rb .req r0
  48. 2: ldrb r2, [r0]
  49. 3: ldrb rb, [r0, #1]
  50. #endif
  51. #ifndef __ARMEB__
  52. orr r2, r2, rb, lsl #8
  53. #else
  54. orr r2, rb, r2, lsl #8
  55. #endif
  56. mov r0, #0
  57. ret lr
  58. ENDPROC(__get_user_2)
  59. ENTRY(__get_user_4)
  60. check_uaccess r0, 4, r1, r2, __get_user_bad
  61. 4: TUSER(ldr) r2, [r0]
  62. mov r0, #0
  63. ret lr
  64. ENDPROC(__get_user_4)
  65. ENTRY(__get_user_8)
  66. check_uaccess r0, 8, r1, r2, __get_user_bad8
  67. #ifdef CONFIG_THUMB2_KERNEL
  68. 5: TUSER(ldr) r2, [r0]
  69. 6: TUSER(ldr) r3, [r0, #4]
  70. #else
  71. 5: TUSER(ldr) r2, [r0], #4
  72. 6: TUSER(ldr) r3, [r0]
  73. #endif
  74. mov r0, #0
  75. ret lr
  76. ENDPROC(__get_user_8)
  77. #ifdef __ARMEB__
  78. ENTRY(__get_user_32t_8)
  79. check_uaccess r0, 8, r1, r2, __get_user_bad
  80. #ifdef CONFIG_CPU_USE_DOMAINS
  81. add r0, r0, #4
  82. 7: ldrt r2, [r0]
  83. #else
  84. 7: ldr r2, [r0, #4]
  85. #endif
  86. mov r0, #0
  87. ret lr
  88. ENDPROC(__get_user_32t_8)
  89. ENTRY(__get_user_64t_1)
  90. check_uaccess r0, 1, r1, r2, __get_user_bad8
  91. 8: TUSER(ldrb) r3, [r0]
  92. mov r0, #0
  93. ret lr
  94. ENDPROC(__get_user_64t_1)
  95. ENTRY(__get_user_64t_2)
  96. check_uaccess r0, 2, r1, r2, __get_user_bad8
  97. #ifdef CONFIG_CPU_USE_DOMAINS
  98. rb .req ip
  99. 9: ldrbt r3, [r0], #1
  100. 10: ldrbt rb, [r0], #0
  101. #else
  102. rb .req r0
  103. 9: ldrb r3, [r0]
  104. 10: ldrb rb, [r0, #1]
  105. #endif
  106. orr r3, rb, r3, lsl #8
  107. mov r0, #0
  108. ret lr
  109. ENDPROC(__get_user_64t_2)
  110. ENTRY(__get_user_64t_4)
  111. check_uaccess r0, 4, r1, r2, __get_user_bad8
  112. 11: TUSER(ldr) r3, [r0]
  113. mov r0, #0
  114. ret lr
  115. ENDPROC(__get_user_64t_4)
  116. #endif
  117. __get_user_bad8:
  118. mov r3, #0
  119. __get_user_bad:
  120. mov r2, #0
  121. mov r0, #-EFAULT
  122. ret lr
  123. ENDPROC(__get_user_bad)
  124. ENDPROC(__get_user_bad8)
  125. .pushsection __ex_table, "a"
  126. .long 1b, __get_user_bad
  127. .long 2b, __get_user_bad
  128. .long 3b, __get_user_bad
  129. .long 4b, __get_user_bad
  130. .long 5b, __get_user_bad8
  131. .long 6b, __get_user_bad8
  132. #ifdef __ARMEB__
  133. .long 7b, __get_user_bad
  134. .long 8b, __get_user_bad8
  135. .long 9b, __get_user_bad8
  136. .long 10b, __get_user_bad8
  137. .long 11b, __get_user_bad8
  138. #endif
  139. .popsection