diff options
author | Denis Vlasenko <vda.linux@googlemail.com> | 2009-01-31 22:26:12 +0300 |
---|---|---|
committer | Denis Vlasenko <vda.linux@googlemail.com> | 2009-01-31 22:26:12 +0300 |
commit | 9ec0ecbfdde2396c4c1c91b4a040ccb006f424c2 (patch) | |
tree | 1a5d4a1c3f542afe6ed737f297c1a77e822e593f /init/init.c | |
parent | 4ae8a05b131836184eb32c440a6bf814ff81b069 (diff) |
init: remove wait() loop on restart, it may be dangerous
Diffstat (limited to 'init/init.c')
-rw-r--r-- | init/init.c | 37 |
1 files changed, 22 insertions, 15 deletions
diff --git a/init/init.c b/init/init.c index 7ba8b67ec..68e624294 100644 --- a/init/init.c +++ b/init/init.c @@ -418,14 +418,16 @@ static pid_t run(const struct init_action *a) _exit(-1); } -static struct init_action *mark_terminated(int pid) +static struct init_action *mark_terminated(pid_t pid) { struct init_action *a; - for (a = init_action_list; a; a = a->next) { - if (a->pid == pid) { - a->pid = 0; - return a; + if (pid > 0) { + for (a = init_action_list; a; a = a->next) { + if (a->pid == pid) { + a->pid = 0; + return a; + } } } return NULL; @@ -444,7 +446,7 @@ static void waitfor(pid_t pid) mark_terminated(wpid); /* Unsafe. SIGTSTP handler might have wait'ed it already */ /*if (wpid == pid) break;*/ - /* More reliable */ + /* More reliable: */ if (kill(pid, 0)) break; } @@ -697,11 +699,11 @@ static void halt_reboot_pwoff(int sig) */ static void stop_handler(int sig UNUSED_PARAM) { - int saved_errno; smallint saved_bb_got_signal; + int saved_errno; - saved_errno = errno; saved_bb_got_signal = bb_got_signal; + saved_errno = errno; signal(SIGCONT, record_signo); while (1) { @@ -714,14 +716,13 @@ static void stop_handler(int sig UNUSED_PARAM) * code which is resilient against this. */ wpid = wait_any_nohang(NULL); - if (wpid > 0) - mark_terminated(wpid); + mark_terminated(wpid); sleep(1); } signal(SIGCONT, SIG_DFL); - bb_got_signal = saved_bb_got_signal; errno = saved_errno; + bb_got_signal = saved_bb_got_signal; } /* Handler for QUIT - exec "restart" action, @@ -747,8 +748,14 @@ static void restart_handler(int sig UNUSED_PARAM) if (open_stdio_to_tty(a->terminal)) { dbg_message(L_CONSOLE, "Trying to re-exec %s", a->command); - while (wait(NULL) > 0) - continue; + /* Theoretically should be safe. + * But in practice, kernel bugs may leave + * unkillable processes, and wait() may block forever. + * Oh well. Hoping "new" init won't be too surprised + * by having children it didn't create. + */ + //while (wait(NULL) > 0) + // continue; init_exec(a->command); } /* Open or exec failed */ @@ -990,14 +997,14 @@ int init_main(int argc UNUSED_PARAM, char **argv) got_sigs |= check_delayed_sigs(); + if (got_sigs) + goto dont_block; /* Wait for any child process to exit. * NB: "delayed" signals will also interrupt this wait(), * bb_signals_recursive_norestart() set them up for that. * This guarantees we won't be stuck here * till next orphan dies. */ - if (got_sigs) - goto dont_block; wpid = wait(NULL); while (wpid > 0) { struct init_action *a = mark_terminated(wpid); |