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| author | Denys Vlasenko | 2017-11-02 15:25:28 +0100 |
|---|---|---|
| committer | Denys Vlasenko | 2017-11-02 15:25:28 +0100 |
| commit | f5e8b4278822f2413bf7e47466f55cc1a0fcca9a (patch) | |
| tree | 831d2e2e32d4ede4dcb06be749d475ed72b868a3 | |
| parent | 9c143ce52da11ec3d21a3491c3749841d3dc10f0 (diff) | |
| download | busybox-f5e8b4278822f2413bf7e47466f55cc1a0fcca9a.zip busybox-f5e8b4278822f2413bf7e47466f55cc1a0fcca9a.tar.gz | |
init: reduce the window when init can lose reboot/poweroff signals
function old new delta
init_main 695 712 +17
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
| -rw-r--r-- | init/init.c | 31 |
1 files changed, 8 insertions, 23 deletions
diff --git a/init/init.c b/init/init.c index 5304e5c..6f3374e 100644 --- a/init/init.c +++ b/init/init.c @@ -1064,6 +1064,12 @@ int init_main(int argc UNUSED_PARAM, char **argv) #endif if (!DEBUG_INIT) { + /* Some users send poweroff signals to init VERY early. + * To handle this, mask signals early, + * and unmask them only after signal handlers are installed. + */ + sigprocmask_allsigs(SIG_BLOCK); + /* Expect to be invoked as init with PID=1 or be invoked as linuxrc */ if (getpid() != 1 && (!ENABLE_LINUXRC || applet_name[0] != 'l') /* not linuxrc? */ @@ -1106,29 +1112,6 @@ int init_main(int argc UNUSED_PARAM, char **argv) message(L_CONSOLE | L_LOG, "init started: %s", bb_banner); #endif -#if 0 -/* It's 2013, does anyone really still depend on this? */ -/* If you do, consider adding swapon to sysinit actions then! */ -/* struct sysinfo is linux-specific */ -# ifdef __linux__ - /* Make sure there is enough memory to do something useful. */ - /*if (ENABLE_SWAPONOFF) - WRONG: we may have non-bbox swapon*/ { - struct sysinfo info; - - if (sysinfo(&info) == 0 - && (info.mem_unit ? info.mem_unit : 1) * (long long)info.totalram < 1024*1024 - ) { - message(L_CONSOLE, "Low memory, forcing swapon"); - /* swapon -a requires /proc typically */ - new_init_action(SYSINIT, "mount -t proc proc /proc", ""); - /* Try to turn on swap */ - new_init_action(SYSINIT, "swapon -a", ""); - run_actions(SYSINIT); /* wait and removing */ - } - } -# endif -#endif - /* Check if we are supposed to be in single user mode */ if (argv[1] && (strcmp(argv[1], "single") == 0 || strcmp(argv[1], "-s") == 0 || LONE_CHAR(argv[1], '1')) @@ -1204,6 +1187,8 @@ int init_main(int argc UNUSED_PARAM, char **argv) + (1 << SIGHUP) /* reread /etc/inittab */ #endif , record_signo); + + sigprocmask_allsigs(SIG_UNBLOCK); } /* Now run everything that needs to be run */ |