__longjmp.S 3.3 KB

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  1. /* Copyright (C) 1997-2016 Free Software Foundation, Inc.
  2. This file is part of the GNU C Library.
  3. The GNU C Library is free software; you can redistribute it and/or
  4. modify it under the terms of the GNU Lesser General Public License as
  5. published by the Free Software Foundation; either version 2.1 of the
  6. License, or (at your option) any later version.
  7. The GNU C Library is distributed in the hope that it will be useful,
  8. but WITHOUT ANY WARRANTY; without even the implied warranty of
  9. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  10. Lesser General Public License for more details.
  11. You should have received a copy of the GNU Lesser General Public
  12. License along with the GNU C Library. If not, see
  13. <http://www.gnu.org/licenses/>. */
  14. #include <sysdep.h>
  15. #include <jmpbuf-offsets.h>
  16. /* __longjmp(jmpbuf, val) */
  17. ENTRY (__longjmp)
  18. cfi_def_cfa(x0, 0)
  19. cfi_offset(x19, JB_X19<<3)
  20. cfi_offset(x20, JB_X20<<3)
  21. cfi_offset(x21, JB_X21<<3)
  22. cfi_offset(x22, JB_X22<<3)
  23. cfi_offset(x23, JB_X23<<3)
  24. cfi_offset(x24, JB_X24<<3)
  25. cfi_offset(x25, JB_X25<<3)
  26. cfi_offset(x26, JB_X26<<3)
  27. cfi_offset(x27, JB_X27<<3)
  28. cfi_offset(x28, JB_X28<<3)
  29. cfi_offset(x29, JB_X29<<3)
  30. cfi_offset(x30, JB_LR<<3)
  31. cfi_offset( d8, JB_D8<<3)
  32. cfi_offset( d9, JB_D9<<3)
  33. cfi_offset(d10, JB_D10<<3)
  34. cfi_offset(d11, JB_D11<<3)
  35. cfi_offset(d12, JB_D12<<3)
  36. cfi_offset(d13, JB_D13<<3)
  37. cfi_offset(d14, JB_D14<<3)
  38. cfi_offset(d15, JB_D15<<3)
  39. ldp x19, x20, [x0, #JB_X19<<3]
  40. ldp x21, x22, [x0, #JB_X21<<3]
  41. ldp x23, x24, [x0, #JB_X23<<3]
  42. ldp x25, x26, [x0, #JB_X25<<3]
  43. ldp x27, x28, [x0, #JB_X27<<3]
  44. ldp x29, x30, [x0, #JB_X29<<3]
  45. /* longjmp probe takes 3 arguments, address of jump buffer as
  46. first argument (8@x0), return value as second argument (-4@x1),
  47. and target address (8@x30), respectively. */
  48. //LIBC_PROBE (longjmp, 3, 8@x0, -4@x1, 8@x30)
  49. ldp d8, d9, [x0, #JB_D8<<3]
  50. ldp d10, d11, [x0, #JB_D10<<3]
  51. ldp d12, d13, [x0, #JB_D12<<3]
  52. ldp d14, d15, [x0, #JB_D14<<3]
  53. /* Originally this was implemented with a series of
  54. .cfi_restore() directives.
  55. The theory was that cfi_restore should revert to previous
  56. frame value is the same as the current value. In practice
  57. this doesn't work, even after cfi_restore() gdb continues
  58. to try to recover a previous frame value offset from x0,
  59. which gets stuffed after a few more instructions. The
  60. cfi_same_value() mechanism appears to work fine. */
  61. cfi_same_value(x19)
  62. cfi_same_value(x20)
  63. cfi_same_value(x21)
  64. cfi_same_value(x22)
  65. cfi_same_value(x23)
  66. cfi_same_value(x24)
  67. cfi_same_value(x25)
  68. cfi_same_value(x26)
  69. cfi_same_value(x27)
  70. cfi_same_value(x28)
  71. cfi_same_value(x29)
  72. cfi_same_value(x30)
  73. cfi_same_value(d8)
  74. cfi_same_value(d9)
  75. cfi_same_value(d10)
  76. cfi_same_value(d11)
  77. cfi_same_value(d12)
  78. cfi_same_value(d13)
  79. cfi_same_value(d14)
  80. cfi_same_value(d15)
  81. ldr x5, [x0, #JB_SP<<3]
  82. mov sp, x5
  83. /* longjmp_target probe takes 3 arguments, address of jump buffer
  84. as first argument (8@x0), return value as second argument (-4@x1),
  85. and target address (8@x30), respectively. */
  86. //LIBC_PROBE (longjmp_target, 3, 8@x0, -4@x1, 8@x30)
  87. cmp x1, #0
  88. mov x0, #1
  89. csel x0, x1, x0, ne
  90. /* Use br instead of ret because ret is guaranteed to mispredict */
  91. br x30
  92. END (__longjmp)
  93. libc_hidden_def(__longjmp)