projects / lxc.git / blame
| Commit | Line | Data |
|---|---|---|
| 99be5c8c WB |
1 | From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 |
| 2 | From: Tycho Andersen <tycho@tycho.ws> | |
| 3 | Date: Wed, 4 Apr 2018 17:45:29 -0600 | |
| 4 | Subject: [PATCH] fix signal sending in lxc.init | |
| 5 | ||
| 6 | The problem here is that these two clauses were ordered backwards: we first | |
| 7 | check if the signal came from not the init pid, and if it did, then we give | |
| 8 | a notice and return. The comment notes that this is intended to protect | |
| 9 | against SIGCHLD, but we don't in fact know if the signal is a SIGCHLD yet, | |
| 10 | because that's tested in the next hunk. | |
| 11 | ||
| 12 | The symptom is that if I e.g. send SIGTERM from the outside world to the | |
| 13 | container init, it ignores it and gives this notice. If we re-order these | |
| 14 | clauses, it forwards non SIGCHLD signals, and ignores SIGCHLD signals from | |
| 15 | things that aren't the real container process. | |
| 16 | ||
| 17 | Signed-off-by: Tycho Andersen <tycho@tycho.ws> | |
| 18 | --- | |
| 19 | src/lxc/start.c | 12 ++++++------ | |
| 20 | 1 file changed, 6 insertions(+), 6 deletions(-) | |
| 21 | ||
| 22 | diff --git a/src/lxc/start.c b/src/lxc/start.c | |
| 23 | index ae13aae9..1982270e 100644 | |
| 24 | --- a/src/lxc/start.c | |
| 25 | +++ b/src/lxc/start.c | |
| 26 | @@ -380,6 +380,12 @@ static int signal_handler(int fd, uint32_t events, void *data, | |
| 27 | return hdlr->init_died ? LXC_MAINLOOP_CLOSE : 0; | |
| 28 | } | |
| 29 | ||
| 30 | + if (siginfo.ssi_signo != SIGCHLD) { | |
| 31 | + kill(hdlr->pid, siginfo.ssi_signo); | |
| 32 | + INFO("Forwarded signal %d to pid %d", siginfo.ssi_signo, hdlr->pid); | |
| 33 | + return hdlr->init_died ? LXC_MAINLOOP_CLOSE : 0; | |
| 34 | + } | |
| 35 | + | |
| 36 | /* More robustness, protect ourself from a SIGCHLD sent | |
| 37 | * by a process different from the container init. | |
| 38 | */ | |
| 39 | @@ -389,12 +395,6 @@ static int signal_handler(int fd, uint32_t events, void *data, | |
| 40 | return hdlr->init_died ? LXC_MAINLOOP_CLOSE : 0; | |
| 41 | } | |
| 42 | ||
| 43 | - if (siginfo.ssi_signo != SIGCHLD) { | |
| 44 | - kill(hdlr->pid, siginfo.ssi_signo); | |
| 45 | - INFO("Forwarded signal %d to pid %d", siginfo.ssi_signo, hdlr->pid); | |
| 46 | - return hdlr->init_died ? LXC_MAINLOOP_CLOSE : 0; | |
| 47 | - } | |
| 48 | - | |
| 49 | if (siginfo.ssi_code == CLD_STOPPED) { | |
| 50 | INFO("Container init process was stopped"); | |
| 51 | return hdlr->init_died ? LXC_MAINLOOP_CLOSE : 0; | |
| 52 | -- | |
| 53 | 2.11.0 | |
| 54 |