* [Qemu-devel] [PATCH v3] libvhost-user-glib: fix VugDev main fd cleanup
@ 2019-08-27 12:49 Johannes Berg
2019-08-27 13:43 ` Marc-André Lureau
0 siblings, 1 reply; 3+ messages in thread
From: Johannes Berg @ 2019-08-27 12:49 UTC (permalink / raw)
To: qemu-devel; +Cc: Marc-André Lureau, Johannes Berg
From: Johannes Berg <johannes.berg@intel.com>
If you try to make a device implementation that can handle multiple
connections and allow disconnections (which requires overriding the
VHOST_USER_NONE handling), then glib will warn that we remove a src
while it's still on the mainloop, and will poll() an FD that doesn't
exist anymore.
Fix this by making vug_source_new() require pairing with the new
vug_source_destroy() so we can keep the GSource referenced in the
meantime.
Note that this requires calling the new API in vhost-user-input.
vhost-user-gpu also uses vug_source_new(), but never seems to free
the result at all, so I haven't changed anything there.
Fixes: 8bb7ddb78a1c ("libvhost-user: add glib source helper")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
contrib/libvhost-user/libvhost-user-glib.c | 15 ++++++++++++---
contrib/libvhost-user/libvhost-user-glib.h | 1 +
contrib/vhost-user-input/main.c | 6 ++----
3 files changed, 15 insertions(+), 7 deletions(-)
diff --git a/contrib/libvhost-user/libvhost-user-glib.c b/contrib/libvhost-user/libvhost-user-glib.c
index 99edd2f3de45..eaf88b8aa749 100644
--- a/contrib/libvhost-user/libvhost-user-glib.c
+++ b/contrib/libvhost-user/libvhost-user-glib.c
@@ -91,7 +91,6 @@ vug_source_new(VugDev *gdev, int fd, GIOCondition cond,
g_source_add_poll(gsrc, &src->gfd);
id = g_source_attach(gsrc, NULL);
g_assert(id);
- g_source_unref(gsrc);
return gsrc;
}
@@ -131,6 +130,16 @@ static void vug_watch(VuDev *dev, int condition, void *data)
}
}
+void vug_source_destroy(GSource *src)
+{
+ if (!src) {
+ return;
+ }
+
+ g_source_unref(src);
+ g_source_destroy(src);
+}
+
bool
vug_init(VugDev *dev, uint16_t max_queues, int socket,
vu_panic_cb panic, const VuDevIface *iface)
@@ -144,7 +153,7 @@ vug_init(VugDev *dev, uint16_t max_queues, int socket,
}
dev->fdmap = g_hash_table_new_full(NULL, NULL, NULL,
- (GDestroyNotify) g_source_destroy);
+ (GDestroyNotify) vug_source_destroy);
dev->src = vug_source_new(dev, socket, G_IO_IN, vug_watch, NULL);
@@ -157,5 +166,5 @@ vug_deinit(VugDev *dev)
g_assert(dev);
g_hash_table_unref(dev->fdmap);
- g_source_unref(dev->src);
+ vug_source_destroy(dev->src);
}
diff --git a/contrib/libvhost-user/libvhost-user-glib.h b/contrib/libvhost-user/libvhost-user-glib.h
index 64d539d93aba..1a79a4916ef2 100644
--- a/contrib/libvhost-user/libvhost-user-glib.h
+++ b/contrib/libvhost-user/libvhost-user-glib.h
@@ -31,5 +31,6 @@ void vug_deinit(VugDev *dev);
GSource *vug_source_new(VugDev *dev, int fd, GIOCondition cond,
vu_watch_cb vu_cb, gpointer data);
+void vug_source_destroy(GSource *src);
#endif /* LIBVHOST_USER_GLIB_H */
diff --git a/contrib/vhost-user-input/main.c b/contrib/vhost-user-input/main.c
index 449fd2171a5a..7d6b0f9d80cc 100644
--- a/contrib/vhost-user-input/main.c
+++ b/contrib/vhost-user-input/main.c
@@ -187,7 +187,7 @@ vi_queue_set_started(VuDev *dev, int qidx, bool started)
}
if (!started && vi->evsrc) {
- g_source_destroy(vi->evsrc);
+ vug_source_destroy(vi->evsrc);
vi->evsrc = NULL;
}
}
@@ -401,9 +401,7 @@ main(int argc, char *argv[])
vug_deinit(&vi.dev);
- if (vi.evsrc) {
- g_source_unref(vi.evsrc);
- }
+ vugg_source_destroy(vi.evsrc);
g_array_free(vi.config, TRUE);
g_free(vi.queue);
return 0;
--
2.23.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [Qemu-devel] [PATCH v3] libvhost-user-glib: fix VugDev main fd cleanup
2019-08-27 12:49 [Qemu-devel] [PATCH v3] libvhost-user-glib: fix VugDev main fd cleanup Johannes Berg
@ 2019-08-27 13:43 ` Marc-André Lureau
2019-08-28 8:33 ` Johannes Berg
0 siblings, 1 reply; 3+ messages in thread
From: Marc-André Lureau @ 2019-08-27 13:43 UTC (permalink / raw)
To: Johannes Berg; +Cc: qemu-devel, Johannes Berg
Hi
On Tue, Aug 27, 2019 at 4:49 PM Johannes Berg <johannes@sipsolutions.net> wrote:
>
> From: Johannes Berg <johannes.berg@intel.com>
>
> If you try to make a device implementation that can handle multiple
> connections and allow disconnections (which requires overriding the
> VHOST_USER_NONE handling), then glib will warn that we remove a src
> while it's still on the mainloop, and will poll() an FD that doesn't
> exist anymore.
>
> Fix this by making vug_source_new() require pairing with the new
> vug_source_destroy() so we can keep the GSource referenced in the
> meantime.
>
> Note that this requires calling the new API in vhost-user-input.
> vhost-user-gpu also uses vug_source_new(), but never seems to free
> the result at all, so I haven't changed anything there.
>
> Fixes: 8bb7ddb78a1c ("libvhost-user: add glib source helper")
> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
> ---
> contrib/libvhost-user/libvhost-user-glib.c | 15 ++++++++++++---
> contrib/libvhost-user/libvhost-user-glib.h | 1 +
> contrib/vhost-user-input/main.c | 6 ++----
> 3 files changed, 15 insertions(+), 7 deletions(-)
>
> diff --git a/contrib/libvhost-user/libvhost-user-glib.c b/contrib/libvhost-user/libvhost-user-glib.c
> index 99edd2f3de45..eaf88b8aa749 100644
> --- a/contrib/libvhost-user/libvhost-user-glib.c
> +++ b/contrib/libvhost-user/libvhost-user-glib.c
> @@ -91,7 +91,6 @@ vug_source_new(VugDev *gdev, int fd, GIOCondition cond,
> g_source_add_poll(gsrc, &src->gfd);
> id = g_source_attach(gsrc, NULL);
> g_assert(id);
> - g_source_unref(gsrc);
>
> return gsrc;
> }
> @@ -131,6 +130,16 @@ static void vug_watch(VuDev *dev, int condition, void *data)
> }
> }
>
> +void vug_source_destroy(GSource *src)
> +{
> + if (!src) {
> + return;
> + }
> +
> + g_source_unref(src);
> + g_source_destroy(src);
I would call destroy() (detach) before unref().
> +}
> +
> bool
> vug_init(VugDev *dev, uint16_t max_queues, int socket,
> vu_panic_cb panic, const VuDevIface *iface)
> @@ -144,7 +153,7 @@ vug_init(VugDev *dev, uint16_t max_queues, int socket,
> }
>
> dev->fdmap = g_hash_table_new_full(NULL, NULL, NULL,
> - (GDestroyNotify) g_source_destroy);
> + (GDestroyNotify) vug_source_destroy);
>
> dev->src = vug_source_new(dev, socket, G_IO_IN, vug_watch, NULL);
>
> @@ -157,5 +166,5 @@ vug_deinit(VugDev *dev)
> g_assert(dev);
>
> g_hash_table_unref(dev->fdmap);
> - g_source_unref(dev->src);
> + vug_source_destroy(dev->src);
> }
> diff --git a/contrib/libvhost-user/libvhost-user-glib.h b/contrib/libvhost-user/libvhost-user-glib.h
> index 64d539d93aba..1a79a4916ef2 100644
> --- a/contrib/libvhost-user/libvhost-user-glib.h
> +++ b/contrib/libvhost-user/libvhost-user-glib.h
> @@ -31,5 +31,6 @@ void vug_deinit(VugDev *dev);
>
> GSource *vug_source_new(VugDev *dev, int fd, GIOCondition cond,
> vu_watch_cb vu_cb, gpointer data);
> +void vug_source_destroy(GSource *src);
>
> #endif /* LIBVHOST_USER_GLIB_H */
> diff --git a/contrib/vhost-user-input/main.c b/contrib/vhost-user-input/main.c
> index 449fd2171a5a..7d6b0f9d80cc 100644
> --- a/contrib/vhost-user-input/main.c
> +++ b/contrib/vhost-user-input/main.c
> @@ -187,7 +187,7 @@ vi_queue_set_started(VuDev *dev, int qidx, bool started)
> }
>
> if (!started && vi->evsrc) {
> - g_source_destroy(vi->evsrc);
> + vug_source_destroy(vi->evsrc);
> vi->evsrc = NULL;
> }
> }
> @@ -401,9 +401,7 @@ main(int argc, char *argv[])
>
> vug_deinit(&vi.dev);
>
> - if (vi.evsrc) {
> - g_source_unref(vi.evsrc);
> - }
> + vugg_source_destroy(vi.evsrc);
typo
> g_array_free(vi.config, TRUE);
> g_free(vi.queue);
> return 0;
vhost-user-input calls g_source_destroy(), please replace it too with
vug_source_destroy().
vhost-user-gpu "renderer_source" leaks, not this patch fault, but
worth to mention in the commit. Feel free to add a second commit to
fix that too.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [Qemu-devel] [PATCH v3] libvhost-user-glib: fix VugDev main fd cleanup
2019-08-27 13:43 ` Marc-André Lureau
@ 2019-08-28 8:33 ` Johannes Berg
0 siblings, 0 replies; 3+ messages in thread
From: Johannes Berg @ 2019-08-28 8:33 UTC (permalink / raw)
To: Marc-André Lureau; +Cc: qemu-devel
Hi,
> > + g_source_unref(src);
> > + g_source_destroy(src);
>
> I would call destroy() (detach) before unref().
Fair enough. I think there's an internal reference, but it's probably
safer that way.
> > + vugg_source_destroy(vi.evsrc);
>
> typo
Oops. I thought I compiled it, I guess I didn't, fixed.
> > g_array_free(vi.config, TRUE);
> > g_free(vi.queue);
> > return 0;
>
> vhost-user-input calls g_source_destroy(), please replace it too with
> vug_source_destroy().
That's what the patch above was, apart from the typo :-)
> vhost-user-gpu "renderer_source" leaks, not this patch fault, but
> worth to mention in the commit.
I did:
>> vhost-user-gpu also uses vug_source_new(), but never seems to free
>> the result at all, so I haven't changed anything there.
> Feel free to add a second commit to fix that too.
I looked at it briefly but couldn't unwind the paths, sorry.
johannes
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2019-08-28 8:36 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2019-08-27 12:49 [Qemu-devel] [PATCH v3] libvhost-user-glib: fix VugDev main fd cleanup Johannes Berg
2019-08-27 13:43 ` Marc-André Lureau
2019-08-28 8:33 ` Johannes Berg
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