kqueue: Do not return early from _kqsub_cancel

_kqsub_free assumes the caller has called _kqsub_cancel before calling
it. It checks if both 'deps' and 'fd' have been freed and aborts when
the condition is not met. Since the only caller of _kqsub_free is
g_kqueue_file_monitor_finalize, which does call _kqsub_cancel before
calling _kqsub_free, it seems to be correct for _kqsub_free to assert
values of these two members there.

However, it is possible for _kqsub_cancel to return early without
freeing any resource _kqsub_free expects to be freed. When the kevent
call fails, _kqsub_cancel does not free anything and _kqsub_free aborts
with assertion failure. This is an unexpected behavior, and it can be
fixed by always freeing resources in _kqsub_cancel.

Fixes: https://gitlab.gnome.org/GNOME/glib/issues/1935
This commit is contained in:
Ting-Wei Lan 2019-11-17 22:39:07 +08:00
parent 8c68e30eb8
commit 6d734b895a

View File

@ -122,7 +122,7 @@ static gboolean g_kqueue_file_monitor_is_supported (void);
static kqueue_sub *_kqsub_new (gchar *, gchar *, GKqueueFileMonitor *, GFileMonitorSource *);
static void _kqsub_free (kqueue_sub *);
static gboolean _kqsub_cancel (kqueue_sub *);
static void _kqsub_cancel (kqueue_sub *);
#ifndef O_EVTONLY
@ -547,7 +547,7 @@ _kqsub_free (kqueue_sub *sub)
g_slice_free (kqueue_sub, sub);
}
static gboolean
static void
_kqsub_cancel (kqueue_sub *sub)
{
/* WARNING: Before calling this function, you must hold a lock on kq_lock
@ -563,7 +563,6 @@ _kqsub_cancel (kqueue_sub *sub)
if (kevent (kq_queue, &ev, 1, NULL, 0, NULL) == -1)
{
g_warning ("Unable to remove event for %s: %s", sub->filename, g_strerror (errno));
return FALSE;
}
close (sub->fd);
sub->fd = -1;
@ -576,8 +575,6 @@ _kqsub_cancel (kqueue_sub *sub)
dl_free (sub->deps);
sub->deps = NULL;
}
return TRUE;
}
gboolean