util/log: Close per-thread log file on thread termination

When `-D ${logfile} -d tid` is passed, qemu_log_trylock() creates
a dedicated log file for the current thread and opens it. The
corresponding file descriptor is cached in a __thread variable.
Nothing is done to close the corresponding file descriptor when the
thread terminates though and the file descriptor is leaked.

The issue was found during code inspection and reproduced manually.

Fix that with an atexit notifier.

Fixes: 4e51069d67 ("util/log: Support per-thread log files")
Cc: richard.henderson@linaro.org
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20221021105734.555797-1-groug@kaod.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Greg Kurz 2022-10-21 12:57:34 +02:00 committed by Paolo Bonzini
parent 19e2a9fb9d
commit eff3de52f2

View File

@ -42,6 +42,7 @@ static QemuMutex global_mutex;
static char *global_filename;
static FILE *global_file;
static __thread FILE *thread_file;
static __thread Notifier qemu_log_thread_cleanup_notifier;
int qemu_loglevel;
static bool log_append;
@ -77,6 +78,12 @@ static int log_thread_id(void)
#endif
}
static void qemu_log_thread_cleanup(Notifier *n, void *unused)
{
fclose(thread_file);
thread_file = NULL;
}
/* Lock/unlock output. */
FILE *qemu_log_trylock(void)
@ -93,6 +100,8 @@ FILE *qemu_log_trylock(void)
return NULL;
}
thread_file = logfile;
qemu_log_thread_cleanup_notifier.notify = qemu_log_thread_cleanup;
qemu_thread_atexit_add(&qemu_log_thread_cleanup_notifier);
} else {
rcu_read_lock();
/*