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fa535f3e4

Denys Vlasenko

2015-03-02

SUCCESS Duration: 152s

Subject

runsvdir: (almost) close a signal race

Binary

No binary (build failed)

Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

—

Build Log

(log yok)

Commit Diff GitHub →

runit/runsvdir.c +28 -25

runit/runsvdir.c+28 -25

@@ -59,7 +59,6 @@ struct globals {
	int svnum;
	#if ENABLE_FEATURE_RUNSVDIR_LOG
	char *rplog;
-	int rploglen;
	struct fd_pair logpipe;
	struct pollfd pfd[1];
	unsigned stamplog;
@@ -70,7 +69,6 @@ struct globals {
	#define svdir (G.svdir )
	#define svnum (G.svnum )
	#define rplog (G.rplog )
-	#define rploglen (G.rploglen )
	#define logpipe (G.logpipe )
	#define pfd (G.pfd )
	#define stamplog (G.stamplog )
@@ -219,15 +217,11 @@ int runsvdir_main(int argc UNUSED_PARAM, char **argv)
	struct stat s;
	dev_t last_dev = last_dev; /* for gcc */
	ino_t last_ino = last_ino; /* for gcc */
-	time_t last_mtime = 0;
-	int wstat;
+	time_t last_mtime;
	int curdir;
-	pid_t pid;
-	unsigned deadline;
-	unsigned now;
	unsigned stampcheck;
	int i;
-	int need_rescan = 1;
+	int need_rescan;
	char *opt_s_argv[3];

	INIT_G();
@@ -257,8 +251,7 @@ int runsvdir_main(int argc UNUSED_PARAM, char **argv)
	/* setup log */
	if (*argv) {
	rplog = *argv;
-	rploglen = strlen(rplog);
-	if (rploglen < 7) {
+	if (strlen(rplog) < 7) {
	warnx("log must have at least seven characters");
	} else if (piped_pair(logpipe)) {
	warnx("can't create pipe for log");
@@ -287,11 +280,16 @@ int runsvdir_main(int argc UNUSED_PARAM, char **argv)
	close_on_exec_on(curdir);

	stampcheck = monotonic_sec();
+	need_rescan = 1;
+	last_mtime = 0;

	for (;;) {
+	unsigned now;
+	unsigned sig;
+
	/* collect children */
	for (;;) {
-	pid = wait_any_nohang(&wstat);
+	pid_t pid = wait_any_nohang(NULL);
	if (pid <= 0)
	break;
	for (i = 0; i < svnum; i++) {
@@ -345,15 +343,17 @@ int runsvdir_main(int argc UNUSED_PARAM, char **argv)
	}
	pfd[0].revents = 0;
	#endif
-	deadline = (need_rescan ? 1 : 5);
-	sig_block(SIGCHLD);
+	{
+	unsigned deadline = (need_rescan ? 1 : 5);
+	sig_block(SIGCHLD);
	#if ENABLE_FEATURE_RUNSVDIR_LOG
-	if (rplog)
-	poll(pfd, 1, deadline*1000);
-	else
+	if (rplog)
+	poll(pfd, 1, deadline*1000);
+	else
	#endif
-	sleep(deadline);
-	sig_unblock(SIGCHLD);
+	sleep(deadline);
+	sig_unblock(SIGCHLD);
+	}

	#if ENABLE_FEATURE_RUNSVDIR_LOG
	if (pfd[0].revents & POLLIN) {
@@ -361,21 +361,25 @@ int runsvdir_main(int argc UNUSED_PARAM, char **argv)
	while (read(logpipe.rd, &ch, 1) > 0) {
	if (ch < ' ')
	ch = ' ';
-	for (i = 6; i < rploglen; i++)
+	for (i = 6; rplog[i] != '\0'; i++)
	rplog[i-1] = rplog[i];
-	rplog[rploglen-1] = ch;
+	rplog[i-1] = ch;
	}
	}
	#endif
-	if (!bb_got_signal)
+	sig = bb_got_signal;
+	if (!sig)
	continue;
+	bb_got_signal = 0;

	/* -s SCRIPT: useful if we are init.
	* In this case typically script never returns,
	* it halts/powers off/reboots the system. */
	if (opt_s_argv[0]) {
+	pid_t pid;
+
	/* Single parameter: signal# */
-	opt_s_argv[1] = utoa(bb_got_signal);
+	opt_s_argv[1] = utoa(sig);
	pid = spawn(opt_s_argv);
	if (pid > 0) {
	/* Remembering to wait for _any_ children,
@@ -385,7 +389,7 @@ int runsvdir_main(int argc UNUSED_PARAM, char **argv)
	}
	}

-	if (bb_got_signal == SIGHUP) {
+	if (sig == SIGHUP) {
	for (i = 0; i < svnum; i++)
	if (sv[i].pid)
	kill(sv[i].pid, SIGTERM);
@@ -393,9 +397,8 @@ int runsvdir_main(int argc UNUSED_PARAM, char **argv)
	/* SIGHUP or SIGTERM (or SIGUSRn if we are init) */
	/* Exit unless we are init */
	if (getpid() != 1)
-	return (SIGHUP == bb_got_signal) ? 111 : EXIT_SUCCESS;
+	return (SIGHUP == sig) ? 111 : EXIT_SUCCESS;

	/* init continues to monitor services forever */
-	bb_got_signal = 0;
	} /* for (;;) */
	}