return from signal
syscall is used by the signal handling facility to atomically switch stacks,
restore registers and the thread's signal mask, and return from a signal
context to resume the processing that was interrupted by the signal.
Note that sigcontext contains machine dependent information.
Direct use of
sigreturn is no longer
supported and it is not provided as a function. As used in the signal
trampoline provided by the system, if
fails and returns then the process is terminated.
If successful, the system call does not return. Otherwise, a value of -1 is returned and errno is set to indicate the error.
sigreturn() will fail and the process
context will remain unchanged if one of the following occurs.
- scp points to memory that is not a valid part of the process address space.
- The sigcontext provided is invalid or would improperly raise the privilege level of the process.
sigreturn() function appeared in
4.3BSD. The function was removed from libc in