From d893db6462d21d544b944b6e6711593b21670302 Mon Sep 17 00:00:00 2001 From: Michael Kerrisk Date: Thu, 19 Feb 2015 11:00:59 +0100 Subject: [PATCH] sigreturn.2: Add discussion of rt_sigreturn(2) Signed-off-by: Michael Kerrisk --- man2/sigreturn.2 | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/man2/sigreturn.2 b/man2/sigreturn.2 index 27df8f1b7..554c0e564 100644 --- a/man2/sigreturn.2 +++ b/man2/sigreturn.2 @@ -29,7 +29,7 @@ .\" .TH SIGRETURN 2 2014-12-31 "Linux" "Linux Programmer's Manual" .SH NAME -sigreturn \- return from signal handler and cleanup stack frame +sigreturn, rt_sigreturn \- return from signal handler and cleanup stack frame .SH SYNOPSIS .BI "int sigreturn(...);" .SH DESCRIPTION @@ -120,6 +120,21 @@ the kernel passes control to the trampoline (rather than the signal handler), and the trampoline code calls the signal handler (and then calls .BR sigreturn () once the handler returns). +.\" +.SS C library/kernel ABI differences +The original Linux system call was named +.BR sigreturn (). +However, with the addition of real-time signals in Linux 2.2, +a new system call, +.BR rt_sigreturn () +was added to support an enlarged +.IR sigset_t +type. +The GNU C library +hides these details from us, transparently employing +.BR rt_sigreturn () +when the kernel provides it. +.\" .SH SEE ALSO .BR kill (2), .BR restart_syscall (2),