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| author | David Lamparter <equinox@opensourcerouting.org> | 2024-07-27 01:50:20 +0200 |
|---|---|---|
| committer | David Lamparter <equinox@opensourcerouting.org> | 2024-10-17 13:58:57 +0200 |
| commit | f177663631c25d59643b4a75036586d90c6c25de (patch) | |
| tree | c698146d57fbdf9daf08804df92397f6f5abca3f /lib | |
| parent | lib: zlog stays running on shutdown (diff) | |
| download | frr-f177663631c25d59643b4a75036586d90c6c25de.tar.xz frr-f177663631c25d59643b4a75036586d90c6c25de.zip | |
lib: do not log_memstats() in crash handler
`log_memstats()` is not AS-safe. It can hang the crash handler (or set
your PC on fire, or cause the sun to go supernova - according to POSIX
specs, anyway.)
Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/sigevent.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/lib/sigevent.c b/lib/sigevent.c index 3e69f280d..7c465bfce 100644 --- a/lib/sigevent.c +++ b/lib/sigevent.c @@ -237,8 +237,18 @@ core_handler(int signo, siginfo_t *siginfo, void *context) zlog_signal(signo, "aborting...", siginfo, pc); - /* dump memory stats on core */ - log_memstats(stderr, "core_handler"); + /* there used to be a log_memstats() call here, to dump MTYPE counters + * on a coredump. This is not possible since log_memstats is not + * AS-Safe, as it calls fopen(), fprintf(), and cousins. This can + * lead to a deadlock depending on where we crashed - very much not a + * good thing if the process just hangs there after a crash. + * + * The alarm(1) above tries to alleviate this, but that's really a + * last resort recovery. Stick with AS-safe calls here. + * + * If the fprintf() calls are removed from log_memstats(), this can be + * added back in, since writing to log with zlog_sigsafe() is AS-safe. + */ /* * This is a buffer flush because FRR is going down |