diff options
Diffstat (limited to 'runit')
| -rw-r--r-- | runit/runsv.c | 29 | ||||
| -rw-r--r-- | runit/svlogd.c | 8 |
2 files changed, 23 insertions, 14 deletions
diff --git a/runit/runsv.c b/runit/runsv.c index 61ea240..7fad563 100644 --- a/runit/runsv.c +++ b/runit/runsv.c @@ -149,11 +149,15 @@ static void warn_cannot(const char *m) warn2_cannot(m, ""); } +/* SIGCHLD/TERM handlers are reentrancy-safe because they are unmasked + * only over poll() call, not over memory allocations + * or printouts. Do not need to save/restore errno either, + * as poll() error is not checked there. + */ static void s_child(int sig_no UNUSED_PARAM) { write(selfpipe.wr, "", 1); } - static void s_term(int sig_no UNUSED_PARAM) { sigterm = 1; @@ -380,14 +384,14 @@ static void startservice(struct svdir *s) xdup2(logpipe.wr, 1); } } - /* Non-ignored signals revert to SIG_DFL on exec anyway. - * But we can get signals BEFORE execl(), this is unlikely - * but wouldn't be good... + /* Non-ignored signals revert to SIG_DFL on exec. + * But we can get signals BEFORE execl(), unlikely as that may be. + * SIGCHLD is safe (would merely write to selfpipe), + * but SIGTERM would set sigterm = 1 (with vfork, we affect parent). + * Avoid that. */ - /*bb_signals(0 - + (1 << SIGCHLD) - + (1 << SIGTERM) - , SIG_DFL);*/ + /*signal(SIGCHLD, SIG_DFL);*/ + signal(SIGTERM, SIG_DFL); sig_unblock(SIGCHLD); sig_unblock(SIGTERM); execv(arg[0], (char**) arg); @@ -514,9 +518,13 @@ int runsv_main(int argc UNUSED_PARAM, char **argv) ndelay_on(selfpipe.wr); sig_block(SIGCHLD); - bb_signals_recursive_norestart(1 << SIGCHLD, s_child); sig_block(SIGTERM); - bb_signals_recursive_norestart(1 << SIGTERM, s_term); + /* No particular reason why we don't set SA_RESTART + * (poll() wouldn't restart regardless of that flag), + * we just follow what runit-2.1.2 does: + */ + bb_signals_norestart(1 << SIGCHLD, s_child); + bb_signals_norestart(1 << SIGTERM, s_term); xchdir(dir); /* bss: svd[0].pid = 0; */ @@ -628,6 +636,7 @@ int runsv_main(int argc UNUSED_PARAM, char **argv) sig_unblock(SIGTERM); sig_unblock(SIGCHLD); poll(x, 2 + haslog, 3600*1000); + /* NB: signal handlers can trash errno of poll() */ sig_block(SIGTERM); sig_block(SIGCHLD); diff --git a/runit/svlogd.c b/runit/svlogd.c index 4490492..02c3056 100644 --- a/runit/svlogd.c +++ b/runit/svlogd.c @@ -1111,10 +1111,10 @@ int svlogd_main(int argc, char **argv) sigaddset(&blocked_sigset, SIGALRM); sigaddset(&blocked_sigset, SIGHUP); sigprocmask(SIG_BLOCK, &blocked_sigset, NULL); - bb_signals_recursive_norestart(1 << SIGTERM, sig_term_handler); - bb_signals_recursive_norestart(1 << SIGCHLD, sig_child_handler); - bb_signals_recursive_norestart(1 << SIGALRM, sig_alarm_handler); - bb_signals_recursive_norestart(1 << SIGHUP, sig_hangup_handler); + bb_signals_norestart(1 << SIGTERM, sig_term_handler); + bb_signals_norestart(1 << SIGCHLD, sig_child_handler); + bb_signals_norestart(1 << SIGALRM, sig_alarm_handler); + bb_signals_norestart(1 << SIGHUP, sig_hangup_handler); /* Without timestamps, we don't have to print each line * separately, so we can look for _last_ newline, not first, |