sysv_signal.c 1.9 KB

12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758
  1. /* Copyright (C) 1991, 1992, 1996, 1997, 2005 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, write to the Free
  13. Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  14. 02111-1307 USA. */
  15. #include <errno.h>
  16. #include <signal.h>
  17. #include <string.h> /* For the real memset prototype. */
  18. /* libc_hidden_proto(sigaction) */
  19. /* Tolerate non-threads versions of Posix */
  20. #ifndef SA_ONESHOT
  21. #define SA_ONESHOT 0
  22. #endif
  23. #ifndef SA_NOMASK
  24. #define SA_NOMASK 0
  25. #endif
  26. #ifndef SA_INTERRUPT
  27. #define SA_INTERRUPT 0
  28. #endif
  29. /* Set the handler for the signal SIG to HANDLER,
  30. returning the old handler, or SIG_ERR on error. */
  31. __sighandler_t __sysv_signal (int sig, __sighandler_t handler)
  32. {
  33. struct sigaction act, oact;
  34. /* Check signal extents to protect __sigismember. */
  35. if (handler == SIG_ERR || sig < 1 || sig >= NSIG)
  36. {
  37. __set_errno (EINVAL);
  38. return SIG_ERR;
  39. }
  40. act.sa_handler = handler;
  41. __sigemptyset (&act.sa_mask);
  42. act.sa_flags = (SA_ONESHOT | SA_NOMASK | SA_INTERRUPT) & ~SA_RESTART;
  43. /* In Linux (as of 2.6.25), fails only if sig is SIGKILL or SIGSTOP */
  44. if (sigaction (sig, &act, &oact) < 0)
  45. return SIG_ERR;
  46. return oact.sa_handler;
  47. }
  48. strong_alias(__sysv_signal,sysv_signal)