| Message ID | 20110314125855.GP10151@redhat.com |
|---|---|
| State | New |
| Headers | show |
On Mon, Mar 14, 2011 at 02:58:55PM +0200, Gleb Natapov wrote: > Currently when rogue script kills QEMU process (using TERM/INT/HUP > signal) it looks indistinguishable from system shutdown. Lets report > that QMEU was killed and leave some clues about the killed identity. Good idea, but.... > > Signed-off-by: Gleb Natapov <gleb@redhat.com> > diff --git a/os-posix.c b/os-posix.c > index 38c29d1..7e175e8 100644 > --- a/os-posix.c > +++ b/os-posix.c > @@ -61,8 +61,9 @@ void os_setup_early_signal_handling(void) > sigaction(SIGPIPE, &act, NULL); > } > > -static void termsig_handler(int signal) > +static void termsig_handler(int signal, siginfo_t *info, void *c) > { > + fprintf(stderr, "Got signal %d from pid %d\n", info->si_signo, info->si_pid); > qemu_system_shutdown_request(); ...fprintf() isn't async signal safe. It could deadlock the process if it malloc()s while doing the arg formatting & the interrupted thread was already holding a malloc() lock, or indeed if the stdio impl itself has internal locks which are held. So this data needs to be manually output using just write() Regards, Daniel
On Mon, Mar 14, 2011 at 01:07:40PM +0000, Daniel P. Berrange wrote: > On Mon, Mar 14, 2011 at 02:58:55PM +0200, Gleb Natapov wrote: > > Currently when rogue script kills QEMU process (using TERM/INT/HUP > > signal) it looks indistinguishable from system shutdown. Lets report > > that QMEU was killed and leave some clues about the killed identity. > > Good idea, but.... > > > > > Signed-off-by: Gleb Natapov <gleb@redhat.com> > > diff --git a/os-posix.c b/os-posix.c > > index 38c29d1..7e175e8 100644 > > --- a/os-posix.c > > +++ b/os-posix.c > > @@ -61,8 +61,9 @@ void os_setup_early_signal_handling(void) > > sigaction(SIGPIPE, &act, NULL); > > } > > > > -static void termsig_handler(int signal) > > +static void termsig_handler(int signal, siginfo_t *info, void *c) > > { > > + fprintf(stderr, "Got signal %d from pid %d\n", info->si_signo, info->si_pid); > > qemu_system_shutdown_request(); > > ...fprintf() isn't async signal safe. It could deadlock the process > if it malloc()s while doing the arg formatting & the interrupted > thread was already holding a malloc() lock, or indeed if the stdio > impl itself has internal locks which are held. So this data needs > to be manually output using just write() > Or we can save info->si_signo && info->si_pid in global variables and print this when shutdown is performed by main loop. Will send updated patch. -- Gleb.
diff --git a/os-posix.c b/os-posix.c index 38c29d1..7e175e8 100644 --- a/os-posix.c +++ b/os-posix.c @@ -61,8 +61,9 @@ void os_setup_early_signal_handling(void) sigaction(SIGPIPE, &act, NULL); } -static void termsig_handler(int signal) +static void termsig_handler(int signal, siginfo_t *info, void *c) { + fprintf(stderr, "Got signal %d from pid %d\n", info->si_signo, info->si_pid); qemu_system_shutdown_request(); } @@ -76,7 +77,8 @@ void os_setup_signal_handling(void) struct sigaction act; memset(&act, 0, sizeof(act)); - act.sa_handler = termsig_handler; + act.sa_sigaction = termsig_handler; + act.sa_flags = SA_SIGINFO; sigaction(SIGINT, &act, NULL); sigaction(SIGHUP, &act, NULL); sigaction(SIGTERM, &act, NULL);
Currently when rogue script kills QEMU process (using TERM/INT/HUP signal) it looks indistinguishable from system shutdown. Lets report that QMEU was killed and leave some clues about the killed identity. Signed-off-by: Gleb Natapov <gleb@redhat.com> -- Gleb.