| Message ID | 04b7c48c-eb68-44bb-8bd3-b85647dbbf91@xs4all.nl |
|---|---|
| State | New |
| Headers | show |
| Series | [for,v6.10] Revert "media: v4l2-ctrls: show all owned controls in log_status" | expand |
Hi Hans, Thank you for the patch. On Fri, May 10, 2024 at 09:11:46AM +0200, Hans Verkuil wrote: > This reverts commit 9801b5b28c6929139d6fceeee8d739cc67bb2739. > > This patch introduced a potential deadlock scenario: > > [Wed May 8 10:02:06 2024] Possible unsafe locking scenario: > > [Wed May 8 10:02:06 2024] CPU0 CPU1 > [Wed May 8 10:02:06 2024] ---- ---- > [Wed May 8 10:02:06 2024] lock(vivid_ctrls:1620:(hdl_vid_cap)->_lock); > [Wed May 8 10:02:06 2024] lock(vivid_ctrls:1608:(hdl_user_vid)->_lock); > [Wed May 8 10:02:06 2024] lock(vivid_ctrls:1620:(hdl_vid_cap)->_lock); > [Wed May 8 10:02:06 2024] lock(vivid_ctrls:1608:(hdl_user_vid)->_lock); > > For now just revert. > > Fixes: 9801b5b28c69 ("media: v4l2-ctrls: show all owned controls in log_status") > Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > --- > drivers/media/v4l2-core/v4l2-ctrls-core.c | 18 +++++------------- > 1 file changed, 5 insertions(+), 13 deletions(-) > > diff --git a/drivers/media/v4l2-core/v4l2-ctrls-core.c b/drivers/media/v4l2-core/v4l2-ctrls-core.c > index c59dd691f79f6..eeab6a5eb7bac 100644 > --- a/drivers/media/v4l2-core/v4l2-ctrls-core.c > +++ b/drivers/media/v4l2-core/v4l2-ctrls-core.c > @@ -2507,8 +2507,7 @@ int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl) > EXPORT_SYMBOL(v4l2_ctrl_handler_setup); > > /* Log the control name and value */ > -static void log_ctrl(const struct v4l2_ctrl_handler *hdl, > - struct v4l2_ctrl *ctrl, > +static void log_ctrl(const struct v4l2_ctrl *ctrl, > const char *prefix, const char *colon) > { > if (ctrl->flags & (V4L2_CTRL_FLAG_DISABLED | V4L2_CTRL_FLAG_WRITE_ONLY)) > @@ -2518,11 +2517,7 @@ static void log_ctrl(const struct v4l2_ctrl_handler *hdl, > > pr_info("%s%s%s: ", prefix, colon, ctrl->name); > > - if (ctrl->handler != hdl) > - v4l2_ctrl_lock(ctrl); > ctrl->type_ops->log(ctrl); > - if (ctrl->handler != hdl) > - v4l2_ctrl_unlock(ctrl); > > if (ctrl->flags & (V4L2_CTRL_FLAG_INACTIVE | > V4L2_CTRL_FLAG_GRABBED | > @@ -2541,7 +2536,7 @@ static void log_ctrl(const struct v4l2_ctrl_handler *hdl, > void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl, > const char *prefix) > { > - struct v4l2_ctrl_ref *ref; > + struct v4l2_ctrl *ctrl; > const char *colon = ""; > int len; > > @@ -2553,12 +2548,9 @@ void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl, > if (len && prefix[len - 1] != ' ') > colon = ": "; > mutex_lock(hdl->lock); > - list_for_each_entry(ref, &hdl->ctrl_refs, node) { > - if (ref->from_other_dev || > - (ref->ctrl->flags & V4L2_CTRL_FLAG_DISABLED)) > - continue; > - log_ctrl(hdl, ref->ctrl, prefix, colon); > - } > + list_for_each_entry(ctrl, &hdl->ctrls, node) > + if (!(ctrl->flags & V4L2_CTRL_FLAG_DISABLED)) > + log_ctrl(ctrl, prefix, colon); > mutex_unlock(hdl->lock); > } > EXPORT_SYMBOL(v4l2_ctrl_handler_log_status);
diff --git a/drivers/media/v4l2-core/v4l2-ctrls-core.c b/drivers/media/v4l2-core/v4l2-ctrls-core.c index c59dd691f79f6..eeab6a5eb7bac 100644 --- a/drivers/media/v4l2-core/v4l2-ctrls-core.c +++ b/drivers/media/v4l2-core/v4l2-ctrls-core.c @@ -2507,8 +2507,7 @@ int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl) EXPORT_SYMBOL(v4l2_ctrl_handler_setup); /* Log the control name and value */ -static void log_ctrl(const struct v4l2_ctrl_handler *hdl, - struct v4l2_ctrl *ctrl, +static void log_ctrl(const struct v4l2_ctrl *ctrl, const char *prefix, const char *colon) { if (ctrl->flags & (V4L2_CTRL_FLAG_DISABLED | V4L2_CTRL_FLAG_WRITE_ONLY)) @@ -2518,11 +2517,7 @@ static void log_ctrl(const struct v4l2_ctrl_handler *hdl, pr_info("%s%s%s: ", prefix, colon, ctrl->name); - if (ctrl->handler != hdl) - v4l2_ctrl_lock(ctrl); ctrl->type_ops->log(ctrl); - if (ctrl->handler != hdl) - v4l2_ctrl_unlock(ctrl); if (ctrl->flags & (V4L2_CTRL_FLAG_INACTIVE | V4L2_CTRL_FLAG_GRABBED | @@ -2541,7 +2536,7 @@ static void log_ctrl(const struct v4l2_ctrl_handler *hdl, void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl, const char *prefix) { - struct v4l2_ctrl_ref *ref; + struct v4l2_ctrl *ctrl; const char *colon = ""; int len; @@ -2553,12 +2548,9 @@ void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl, if (len && prefix[len - 1] != ' ') colon = ": "; mutex_lock(hdl->lock); - list_for_each_entry(ref, &hdl->ctrl_refs, node) { - if (ref->from_other_dev || - (ref->ctrl->flags & V4L2_CTRL_FLAG_DISABLED)) - continue; - log_ctrl(hdl, ref->ctrl, prefix, colon); - } + list_for_each_entry(ctrl, &hdl->ctrls, node) + if (!(ctrl->flags & V4L2_CTRL_FLAG_DISABLED)) + log_ctrl(ctrl, prefix, colon); mutex_unlock(hdl->lock); } EXPORT_SYMBOL(v4l2_ctrl_handler_log_status);
This reverts commit 9801b5b28c6929139d6fceeee8d739cc67bb2739. This patch introduced a potential deadlock scenario: [Wed May 8 10:02:06 2024] Possible unsafe locking scenario: [Wed May 8 10:02:06 2024] CPU0 CPU1 [Wed May 8 10:02:06 2024] ---- ---- [Wed May 8 10:02:06 2024] lock(vivid_ctrls:1620:(hdl_vid_cap)->_lock); [Wed May 8 10:02:06 2024] lock(vivid_ctrls:1608:(hdl_user_vid)->_lock); [Wed May 8 10:02:06 2024] lock(vivid_ctrls:1620:(hdl_vid_cap)->_lock); [Wed May 8 10:02:06 2024] lock(vivid_ctrls:1608:(hdl_user_vid)->_lock); For now just revert. Fixes: 9801b5b28c69 ("media: v4l2-ctrls: show all owned controls in log_status") Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> --- drivers/media/v4l2-core/v4l2-ctrls-core.c | 18 +++++------------- 1 file changed, 5 insertions(+), 13 deletions(-)