Copy the siginfo_t structure onto a global copy and pass that as an

argument to eloop_timeout_add_now so that every actionis async signal safe.

diff --git a/dhcpcd.c b/dhcpcd.c
index df1e7447ffb68d3561dd3ae80b6cb61dcc514a46..701dbade6019cf86e135d75afede2a5506e62d24 100644 (file)
--- a/dhcpcd.c
+++ b/dhcpcd.c
@@ -786,73 +786,57 @@ reconf_reboot(int action, int argc, char **argv, int oi)
        sort_interfaces();
 }
 
-/* ARGSUSED */
 static void
-sig_reboot(void *arg)
-{
-       siginfo_t *siginfo = arg;
-       struct if_options *ifo;
-
-       syslog(LOG_INFO, "received SIGALRM from PID %d, rebinding",
-           (int)siginfo->si_pid);
-
-       free_globals();
-       ifav = NULL;
-       ifac = 0;
-       ifdc = 0;
-       ifdv = NULL;
-
-       ifo = read_config(cffile, NULL, NULL, NULL);
-       add_options(NULL, ifo, margc, margv);
-       /* We need to preserve these two options. */
-       if (options & DHCPCD_MASTER)
-               ifo->options |= DHCPCD_MASTER;
-       if (options & DHCPCD_DAEMONISED)
-               ifo->options |= DHCPCD_DAEMONISED;
-       options = ifo->options;
-       free_options(ifo);
-       reconf_reboot(1, ifc, ifv, 0);
-}
-
-static void
-sig_reconf(void *arg)
-{
-       siginfo_t *siginfo = arg;
-       struct interface *ifp;
-
-       syslog(LOG_INFO, "received SIGUSR from PID %d, reconfiguring",
-           (int)siginfo->si_pid);
-       TAILQ_FOREACH(ifp, ifaces, next) {
-               ipv4_applyaddr(ifp);
-       }
-}
-
-static void
-handle_signal(int sig, siginfo_t *siginfo, __unused void *context)
+handle_signal1(void *arg)
 {
+       siginfo_t *si;
        struct interface *ifp;
+       struct if_options *ifo;
        int do_release;
 
+       si = arg;
        do_release = 0;
-       switch (sig) {
+       switch (si->si_signo) {
        case SIGINT:
                syslog(LOG_INFO, "received SIGINT from PID %d, stopping",
-                   (int)siginfo->si_pid);
+                   (int)si->si_pid);
                break;
        case SIGTERM:
                syslog(LOG_INFO, "received SIGTERM from PID %d, stopping",
-                   (int)siginfo->si_pid);
+                   (int)si->si_pid);
                break;
        case SIGALRM:
-               eloop_timeout_add_now(sig_reboot, siginfo);
+               syslog(LOG_INFO, "received SIGALRM from PID %d, rebinding",
+                   (int)si->si_pid);
+
+               free_globals();
+               ifav = NULL;
+               ifac = 0;
+               ifdc = 0;
+               ifdv = NULL;
+
+               ifo = read_config(cffile, NULL, NULL, NULL);
+               add_options(NULL, ifo, margc, margv);
+               /* We need to preserve these two options. */
+               if (options & DHCPCD_MASTER)
+                   ifo->options |= DHCPCD_MASTER;
+               if (options & DHCPCD_DAEMONISED)
+                   ifo->options |= DHCPCD_DAEMONISED;
+               options = ifo->options;
+               free_options(ifo);
+               reconf_reboot(1, ifc, ifv, 0);
                return;
        case SIGHUP:
                syslog(LOG_INFO, "received SIGHUP from PID %d, releasing",
-                   (int)siginfo->si_pid);
+                   (int)si->si_pid);
                do_release = 1;
                break;
        case SIGUSR1:
-               eloop_timeout_add_now(sig_reconf, siginfo);
+               syslog(LOG_INFO, "received SIGUSR from PID %d, reconfiguring",
+                   (int)si->si_pid);
+               TAILQ_FOREACH(ifp, ifaces, next) {
+                   ipv4_applyaddr(ifp);
+               }
                return;
        case SIGPIPE:
                syslog(LOG_WARNING, "received SIGPIPE");
@@ -861,7 +845,7 @@ handle_signal(int sig, siginfo_t *siginfo, __unused void *context)
                syslog(LOG_ERR,
                    "received signal %d from PID %d, "
                    "but don't know what to do with it",
-                   sig, (int)siginfo->si_pid);
+                   si->si_signo, (int)si->si_pid);
                return;
        }
 
@@ -883,6 +867,18 @@ handle_signal(int sig, siginfo_t *siginfo, __unused void *context)
        eloop_exit(EXIT_FAILURE);
 }
 
+static siginfo_t dhcpcd_siginfo;
+static void
+handle_signal(__unused int sig, siginfo_t *siginfo, __unused void *context)
+{
+
+       /* So that we can operate safely under a signal we instruct
+        * eloop to pass a copy of the siginfo structure to handle_signal1
+        * as the very first thing to do. */
+       memcpy(&dhcpcd_siginfo, siginfo, sizeof(dhcpcd_siginfo));
+       eloop_timeout_add_now(handle_signal1, &dhcpcd_siginfo);
+}
+
 int
 handle_args(struct fd_list *fd, int argc, char **argv)
 {