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authorDenys Vlasenko <vda.linux@googlemail.com>2015-03-02 16:37:31 (GMT)
committerDenys Vlasenko <vda.linux@googlemail.com>2015-03-02 16:37:31 (GMT)
commitfa535f3e485456a7fd85db060532ea6539670af0 (patch)
tree9107bd0622a7af4abcf8ae08e5ae2d77de4d5669 /runit
parent1eafd4494706c21a87dc66e4e0afa8799b576cb5 (diff)
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runsvdir: (almost) close a signal race
We could lose a signal while processing previous one function old new delta runsvdir_main 1088 1077 -11 Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'runit')
-rw-r--r--runit/runsvdir.c53
1 files changed, 28 insertions, 25 deletions
diff --git a/runit/runsvdir.c b/runit/runsvdir.c
index af7e75b..809c48a 100644
--- a/runit/runsvdir.c
+++ b/runit/runsvdir.c
@@ -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 (;;) */
}