signal: Add __libc_sigaction

The generic implementation basically handle the system agnostic logic
(filtering out the invalid signals) while the __libc_sigaction is
the function with implements the system and architecture bits.

Checked on x86_64-linux-gnu and i686-linux-gnu.

3 files changed, 35 insertions, 6 deletions

diff --git a/signal/Makefile b/signal/Makefile
index 3d8cab1..99889a5 100644
--- a/signal/Makefile
+++ b/signal/Makefile
@@ -35,7 +35,7 @@ headers := signal.h sys/signal.h \
 	   bits/sigstksz.h
 
 routines	:= signal raise killpg \
-		   sigaction sigprocmask kill \
+		   sigaction libc_sigaction sigprocmask kill \
 		   sigpending sigsuspend sigwait \
 		   sigblock sigsetmask sigpause sigvec \
 		   sigstack sigaltstack sigintr \
diff --git a/signal/libc_sigaction.c b/signal/libc_sigaction.c
new file mode 100644
index 0000000..c25913b
--- /dev/null
+++ b/signal/libc_sigaction.c
@@ -0,0 +1,32 @@
+/* Internal sigaction definitions.
+   Copyright (C) 2021 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <signal.h>
+
+/* If ACT is not NULL, change the action for SIG to *ACT.
+   If OACT is not NULL, put the old action for SIG in *OACT.  */
+int
+__libc_sigaction (int sig, const struct sigaction *act,
+		  struct sigaction *oact)
+{
+  __set_errno (ENOSYS);
+  return -1;
+}
+stub_warning (libc_sigaction)
+libc_hidden_def (__libc_sigaction)
diff --git a/signal/sigaction.c b/signal/sigaction.c
index 3bfc179..8d9f755 100644
--- a/signal/sigaction.c
+++ b/signal/sigaction.c
@@ -17,7 +17,7 @@
 
 #include <errno.h>
 #include <signal.h>
-
+#include <internal-signals.h>
 
 /* If ACT is not NULL, change the action for SIG to *ACT.
    If OACT is not NULL, put the old action for SIG in *OACT.  */
@@ -30,10 +30,7 @@ __sigaction (int sig, const struct sigaction *act, struct sigaction *oact)
       return -1;
     }
 
-  __set_errno (ENOSYS);
-  return -1;
+  return __libc_sigaction (sig, act, oact);
 }
 libc_hidden_def (__sigaction)
-stub_warning (sigaction)
-
 weak_alias (__sigaction, sigaction)