diff options
| -rw-r--r-- | lib/log.c | 11 | ||||
| -rw-r--r-- | lib/sigevent.c | 17 |
2 files changed, 28 insertions, 0 deletions
@@ -734,6 +734,17 @@ openzlog (const char *progname, const char *protoname, u_short instance, openlog (progname, syslog_flags, zl->facility); zlog_default = zl; + +#ifdef HAVE_GLIBC_BACKTRACE + /* work around backtrace() using lazily resolved dynamically linked + * symbols, which will otherwise cause funny breakage in the SEGV handler. + * (particularly, the dynamic linker can call malloc(), which uses locks + * in programs linked with -pthread, thus can deadlock.) */ + void *bt[4]; + backtrace (bt, array_size(bt)); + free (backtrace_symbols (bt, 0)); + backtrace_symbols_fd (bt, 0, 0); +#endif } void diff --git a/lib/sigevent.c b/lib/sigevent.c index 09f07180c..b2059a17b 100644 --- a/lib/sigevent.c +++ b/lib/sigevent.c @@ -233,6 +233,18 @@ core_handler(int signo #endif ) { + /* make sure we don't hang in here. default for SIGALRM is terminate. + * - if we're in backtrace for more than a second, abort. */ + struct sigaction sa_default = { .sa_handler = SIG_DFL }; + sigaction (SIGALRM, &sa_default, NULL); + + sigset_t sigset; + sigemptyset (&sigset); + sigaddset (&sigset, SIGALRM); + sigprocmask (SIG_UNBLOCK, &sigset, NULL); + + alarm (1); + zlog_signal(signo, "aborting..." #ifdef SA_SIGINFO , siginfo, program_counter(context) @@ -327,6 +339,11 @@ trap_default_signals(void) act.sa_handler = sigmap[i].handler; act.sa_flags = 0; #endif +#ifdef SA_RESETHAND + /* don't try to print backtraces recursively */ + if (sigmap[i].handler == core_handler) + act.sa_flags |= SA_RESETHAND; +#endif } if (sigaction(sigmap[i].sigs[j],&act,NULL) < 0) zlog_warn("Unable to set signal handler for signal %d: %s", |