From e42efa01c9305eb27616bae2bc314d8e44d129e0 Mon Sep 17 00:00:00 2001
From: Samuel Thibault <samuel.thibault@ens-lyon.org>
Date: Sat, 26 Dec 2020 17:57:52 +0100
Subject: hurd: set sigaction for signal preemptors in arch-independent file

Instead of having the arch-specific trampoline setup code detect whether
preemption happened or not, we'd rather pass it the sigaction. In the
future, this may also allow to change sa_flags from post_signal().
---
 hurd/hurd/signal.h |  3 ++-
 hurd/hurdsig.c     | 22 ++++++++++++++++------
 2 files changed, 18 insertions(+), 7 deletions(-)

(limited to 'hurd')

diff --git a/hurd/hurd/signal.h b/hurd/hurd/signal.h
index 2a0aa20..b31463c 100644
--- a/hurd/hurd/signal.h
+++ b/hurd/hurd/signal.h
@@ -327,7 +327,8 @@ extern void _hurd_internal_post_signal (struct hurd_sigstate *ss,
 
 struct machine_thread_all_state;
 extern struct sigcontext *
-_hurd_setup_sighandler (struct hurd_sigstate *ss, __sighandler_t handler,
+_hurd_setup_sighandler (struct hurd_sigstate *ss, const struct sigaction *action,
+			__sighandler_t handler,
 			int signo, struct hurd_signal_detail *detail,
 			int rpc_wait, struct machine_thread_all_state *state);
 
diff --git a/hurd/hurdsig.c b/hurd/hurdsig.c
index 6fdbf38..dcc1da3 100644
--- a/hurd/hurdsig.c
+++ b/hurd/hurdsig.c
@@ -624,6 +624,13 @@ post_signal (struct hurd_sigstate *ss,
   enum { stop, ignore, core, term, handle } act;
   int ss_suspended;
 
+  /* sigaction for preemptors */
+  struct sigaction preempt_sigaction = {
+    .sa_flags = SA_RESTART
+  };
+
+  struct sigaction *action;
+
   /* Mark the signal as pending.  */
   void mark_pending (void)
     {
@@ -780,12 +787,17 @@ post_signal (struct hurd_sigstate *ss,
     /* Ignore the signal altogether.  */
     act = ignore;
   else if (handler != SIG_ERR)
-    /* Run the preemption-provided handler.  */
-    act = handle;
+    {
+      /* Run the preemption-provided handler.  */
+      action = &preempt_sigaction;
+      act = handle;
+    }
   else
     {
       /* No preemption.  Do normal handling.  */
 
+      action = & _hurd_sigstate_actions (ss) [signo];
+
       if (!untraced && __sigismember (&_hurdsig_traced, signo))
 	{
 	  /* We are being traced.  Stop to tell the debugger of the signal.  */
@@ -800,7 +812,7 @@ post_signal (struct hurd_sigstate *ss,
 	  return NULL;
 	}
 
-      handler = _hurd_sigstate_actions (ss) [signo].sa_handler;
+      handler = action->sa_handler;
 
       if (handler == SIG_DFL)
 	/* Figure out the default action for this signal.  */
@@ -1072,7 +1084,7 @@ post_signal (struct hurd_sigstate *ss,
 
 	/* Call the machine-dependent function to set the thread up
 	   to run the signal handler, and preserve its old context.  */
-	scp = _hurd_setup_sighandler (ss, handler, signo, detail,
+	scp = _hurd_setup_sighandler (ss, action, handler, signo, detail,
 				      wait_for_reply, &thread_state);
 	if (scp == NULL)
 	  goto sigbomb;
@@ -1111,8 +1123,6 @@ post_signal (struct hurd_sigstate *ss,
 	    }
 	}
 
-	struct sigaction *action = & _hurd_sigstate_actions (ss) [signo];
-
 	/* Backdoor extra argument to signal handler.  */
 	scp->sc_error = detail->error;
 
-- 
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