NAME
sigreturn - return from signal handler and cleanup stack frame SYNOPSIS int sigreturn(unsigned long unused); DESCRIPTION When the Linux kernel creates the stack frame for a signal handler, a call to sigreturn() is inserted into the stack frame so that upon return from the signal handler, sigreturn() will be called. This sigreturn() call undoes everything that was done—changing the process's signal mask, switching stacks (see sigaltstack(2))—in order to invoke the signal handler: it restores the process's signal mask, switches stacks, and restores the process's context (registers, proces‐ sor flags), so that the process directly resumes execution at the point where it was interrupted by the signal. RETURN VALUE sigreturn() never returns. FILES /usr/src/linux/arch/i386/kernel/signal.c /usr/src/linux/arch/alpha/kernel/entry.S CONFORMING TO sigreturn() is specific to Linux and should not be used in programs intended to be portable. NOTES The sigreturn() call is used by the kernel to implement signal han‐ dlers. It should never be called directly. Better yet, the specific use of the unused argument varies depending on the architecture. SEE ALSO kill(2), restartsyscall(2), sigaltstack(2), signal(2), signal(7) COLOPHON
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Linux 2013-07-30 SIGRETURN(2)