From: Markus Armbruster <armbru@pond.sub.org>
Date: Sun, 27 Dec 2020 08:30:00 +0000 (+0100)
Subject: lwp: Fix signal wait screwup for multiple different signals
X-Git-Url: http://git.pond.sub.org/?p=empserver;a=commitdiff_plain;h=bfb558dee35875037fdea18a6c7ae2c4a97bec13

lwp: Fix signal wait screwup for multiple different signals

lwpSigWait() clears LwpSigCheck even when signals remain in
LwpSigCaught.  The next empth_wait_for_signal() will then wait until
another one gets caught.  Broken in commit fe2de3d74, v4.3.10.

Fix by clearing it only when LwpSigCaught is empty.

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
---

diff --git a/src/lib/lwp/sig.c b/src/lib/lwp/sig.c
index 04fb9f977..62d19728a 100644
--- a/src/lib/lwp/sig.c
+++ b/src/lib/lwp/sig.c
@@ -91,9 +91,10 @@ static int
 lwpGetSig(sigset_t *set)
 {
     sigset_t save;
-    int i;
+    int i, j;
 
     sigprocmask(SIG_BLOCK, set, &save);
+
     for (i = NSIG - 1; i > 0; i--) {
 	if (sigismember(set, i) > 0 && sigismember(&LwpSigCaught, i) > 0) {
 	    lwpStatus(LwpCurrent, "Got awaited signal %d", i);
@@ -101,6 +102,14 @@ lwpGetSig(sigset_t *set)
 	    break;
 	}
     }
+
+    for (j = i;
+	 sigismember(set, i) > 0 && sigismember(&LwpSigCaught, i) > 0;
+	 j--)
+	;
+    if (!j)
+	LwpSigCheck = 0;
+
     sigprocmask(SIG_SETMASK, &save, NULL);
     return i;
 }
@@ -119,7 +128,6 @@ lwpSigWait(sigset_t *set, int *sig)
     if (LwpSigWaiter)
 	return EBUSY;
     for (;;) {
-	LwpSigCheck = 0;
 	res = lwpGetSig(set);
 	if (res > 0)
 	    break;