sigrestorer.S 2.3 KB

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  1. /* Copyright (C) 1999 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
  5. License as published by the Free Software Foundation; either
  6. version 2.1 of the 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 <bits/arm_asm.h>
  15. #include <sys/syscall.h>
  16. #include <linux/version.h>
  17. /* If no SA_RESTORER function was specified by the application we use
  18. one of these. This avoids the need for the kernel to synthesise a return
  19. instruction on the stack, which would involve expensive cache flushes.
  20. Nowadays (2.6 series, and somewhat earlier) the kernel uses a high page
  21. for signal trampolines, so the cache flushes are not an issue. But since
  22. we do not have a vDSO, continue to use these so that we can provide
  23. unwind information.
  24. Start the unwind tables at least one instruction before the signal
  25. trampoline, because the unwinder will assume we are returning after
  26. a call site.
  27. The signal frame layout changed in 2.6.18. */
  28. .global __default_sa_restorer
  29. .type __default_sa_restorer,%function
  30. .align 2
  31. #ifdef __ARM_EABI__
  32. #ifdef __thumb__
  33. .thumb_func
  34. #endif
  35. .fnstart
  36. .save {r0-r15}
  37. #if LINUX_VERSION_CODE >= 0x020612
  38. .pad #32
  39. #else
  40. .pad #12
  41. #endif
  42. nop
  43. __default_sa_restorer:
  44. mov r7, $SYS_ify(sigreturn)
  45. swi 0x0
  46. .fnend
  47. #else
  48. __default_sa_restorer:
  49. DO_CALL (sigreturn)
  50. #endif
  51. #ifdef __NR_rt_sigreturn
  52. .global __default_rt_sa_restorer
  53. .type __default_rt_sa_restorer,%function
  54. .align 2
  55. #ifdef __ARM_EABI__
  56. #ifdef __thumb__
  57. .thumb_func
  58. #endif
  59. .fnstart
  60. .save {r0-r15}
  61. #if LINUX_VERSION_CODE >= 0x020612
  62. .pad #160
  63. #else
  64. .pad #168
  65. #endif
  66. nop
  67. __default_rt_sa_restorer:
  68. mov r7, $SYS_ify(rt_sigreturn)
  69. swi 0x0
  70. .fnend
  71. #else
  72. __default_rt_sa_restorer:
  73. DO_CALL (rt_sigreturn)
  74. #endif
  75. #endif