8234262: Unmask SIGQUIT in a child process

Reviewed-by: bpb, dholmes, vtewari, stuefe, alanb

Author: Roger Riggs

src/java.base/unix/native/jspawnhelper/jspawnhelper.c

@@ -25,6 +25,7 @@
 
 #include <errno.h>
 #include <fcntl.h>
+#include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
@@ -132,6 +133,7 @@ int main(int argc, char *argv[]) {
     struct stat buf;
     /* argv[0] contains the fd number to read all the child info */
     int r, fdin, fdout;
+    sigset_t unblock_signals;
 
     r = sscanf (argv[argc-1], "%d:%d", &fdin, &fdout);
     if (r == 2 && fcntl(fdin, F_GETFD) != -1) {
@@ -141,6 +143,11 @@ int main(int argc, char *argv[]) {
     } else {
         shutItDown();
     }
+
+    // Reset any mask signals from parent
+    sigemptyset(&unblock_signals);
+    sigprocmask(SIG_SETMASK, &unblock_signals, NULL);
+
     initChildStuff (fdin, fdout, &c);
 
     childProcess (&c);

src/java.base/unix/native/libjava/ProcessImpl_md.c

@@ -773,4 +773,3 @@ Java_java_lang_ProcessImpl_forkAndExec(JNIEnv *env,
     closeSafely(err[0]); err[0] = -1;
     goto Finally;
 }
-

test/jdk/java/lang/ProcessBuilder/UnblockSignals.java

@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code 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 General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+import java.io.IOException;
+
+/*
+ * @test
+ * @summary Verify Signal mask is cleared by ProcessBuilder start
+ * @bug 8234262
+ * @requires (os.family == "linux" | os.family == "mac")
+ * @run main/othervm UnblockSignals
+ * @run main/othervm -Xrs UnblockSignals
+ */
+public class UnblockSignals {
+    public static void main(String[] args)  throws IOException, InterruptedException {
+        // Check that SIGQUIT is not masked, in previous releases it was masked
+        final ProcessBuilder pb = new ProcessBuilder("sleep", "30").inheritIO();
+        Process p = pb.start();
+        System.out.printf("Child %d, %s%n", p.pid(), pb.command());
+        ProcessBuilder killpb = new ProcessBuilder("kill", "-s", "QUIT", Long.toString(p.pid()));
+        Process killp = killpb.start();
+        System.out.printf("Child %d, %s%n", killp.pid(), killpb.command());
+        int killst = killp.waitFor();
+        if (killst != 0) {
+            throw new RuntimeException("Kill process failed, exit status: " + killst);
+        }
+        int sleepStatus = p.waitFor();
+        if (sleepStatus == 0) {
+            throw new RuntimeException("Child not killed");
+        }
+    }
+}