Refactor setting of signal handlers to reduce redundancy

* strace.c (set_sigaction): New function.
(init): Use it instead of sigaction with sigaddset.

diff --git a/strace.c b/strace.c
index 59683d348d4d353c589c483a9db648c1ecc1395c..07d5adac903bd2926687a8552bb04ce0d218d845 100644 (file)
--- a/strace.c
+++ b/strace.c
@@ -1595,6 +1595,17 @@ get_os_release(void)
        return rel;
 }
 
+static void
+set_sigaction(int signo, void (*sighandler)(int), struct sigaction *oldact)
+{
+       /* if signal handler is a function, add the signal to blocked_set */
+       if (sighandler != SIG_IGN && sighandler != SIG_DFL)
+               sigaddset(&blocked_set, signo);
+
+       const struct sigaction sa = { .sa_handler = sighandler };
+       sigaction(signo, &sa, oldact);
+}
+
 /*
  * Initialization part of main() was eating much stack (~0.5k),
  * which was unused after init.
@@ -1608,7 +1619,6 @@ init(int argc, char *argv[])
 {
        int c, i;
        int optF = 0;
-       struct sigaction sa;
 
        progname = argv[0] ? argv[0] : "strace";
 
@@ -1916,35 +1926,24 @@ init(int argc, char *argv[])
                startup_child(argv);
        }
 
-       sa.sa_handler = SIG_IGN;
-       sigemptyset(&sa.sa_mask);
-       sa.sa_flags = 0;
-       sigaction(SIGTTOU, &sa, NULL); /* SIG_IGN */
-       sigaction(SIGTTIN, &sa, NULL); /* SIG_IGN */
+       set_sigaction(SIGTTOU, SIG_IGN, NULL);
+       set_sigaction(SIGTTIN, SIG_IGN, NULL);
        if (opt_intr != INTR_ANYWHERE) {
                if (opt_intr == INTR_BLOCK_TSTP_TOO)
-                       sigaction(SIGTSTP, &sa, NULL); /* SIG_IGN */
+                       set_sigaction(SIGTSTP, SIG_IGN, NULL);
                /*
                 * In interactive mode (if no -o OUTFILE, or -p PID is used),
                 * fatal signals are blocked while syscall stop is processed,
                 * and acted on in between, when waiting for new syscall stops.
                 * In non-interactive mode, signals are ignored.
                 */
-               if (interactive) {
-                       sigaddset(&blocked_set, SIGHUP);
-                       sigaddset(&blocked_set, SIGINT);
-                       sigaddset(&blocked_set, SIGQUIT);
-                       sigaddset(&blocked_set, SIGPIPE);
-                       sigaddset(&blocked_set, SIGTERM);
-                       sa.sa_handler = interrupt;
-               }
-               /* SIG_IGN, or set handler for these */
-               sigaction(SIGHUP, &sa, NULL);
-               sigaction(SIGINT, &sa, NULL);
-               sigaction(SIGQUIT, &sa, NULL);
-               sigaction(SIGPIPE, &sa, NULL);
-               sigaction(SIGTERM, &sa, NULL);
+               set_sigaction(SIGHUP, interactive ? interrupt : SIG_IGN, NULL);
+               set_sigaction(SIGINT, interactive ? interrupt : SIG_IGN, NULL);
+               set_sigaction(SIGQUIT, interactive ? interrupt : SIG_IGN, NULL);
+               set_sigaction(SIGPIPE, interactive ? interrupt : SIG_IGN, NULL);
+               set_sigaction(SIGTERM, interactive ? interrupt : SIG_IGN, NULL);
        }
+
        if (nprocs != 0 || daemonized_tracer)
                startup_attach();