| Message ID | 20201204220139.15272-4-laurent.pinchart+renesas@ideasonboard.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Kieran Bingham |
| Headers | show |
| Series | drm: rcar-du: Fix LVDS-related crash | expand |
Hi Laurent, On Sat, Dec 05, 2020 at 12:01:33AM +0200, Laurent Pinchart wrote: > The encoder->name field can never be non-null in the error path, as that > can only be possible after a successful call to > drm_simple_encoder_init(). Drop the cleanup. > > Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> > --- > drivers/gpu/drm/rcar-du/rcar_du_encoder.c | 5 +---- > 1 file changed, 1 insertion(+), 4 deletions(-) > > diff --git a/drivers/gpu/drm/rcar-du/rcar_du_encoder.c b/drivers/gpu/drm/rcar-du/rcar_du_encoder.c > index 2d40da98144b..0edce24f2053 100644 > --- a/drivers/gpu/drm/rcar-du/rcar_du_encoder.c > +++ b/drivers/gpu/drm/rcar-du/rcar_du_encoder.c > @@ -124,11 +124,8 @@ int rcar_du_encoder_init(struct rcar_du_device *rcdu, > } > > done: > - if (ret < 0) { > - if (encoder->name) > - encoder->funcs->destroy(encoder); This is probably worth a Fixes tag, as accessing encoder->func if drm_simple_encoder_init() has not completed might lead to a NULL pointer dereference. Apart from this, patch looks good Reviewed-by: Jacopo Mondi <jacopo@jmondi.org> Thanks j > + if (ret < 0) > devm_kfree(rcdu->dev, renc); > - } > > return ret; > } > -- > Regards, > > Laurent Pinchart >
Hi Jacopo, On Mon, Dec 14, 2020 at 11:11:08AM +0100, Jacopo Mondi wrote: > On Sat, Dec 05, 2020 at 12:01:33AM +0200, Laurent Pinchart wrote: > > The encoder->name field can never be non-null in the error path, as that > > can only be possible after a successful call to > > drm_simple_encoder_init(). Drop the cleanup. > > > > Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> > > --- > > drivers/gpu/drm/rcar-du/rcar_du_encoder.c | 5 +---- > > 1 file changed, 1 insertion(+), 4 deletions(-) > > > > diff --git a/drivers/gpu/drm/rcar-du/rcar_du_encoder.c b/drivers/gpu/drm/rcar-du/rcar_du_encoder.c > > index 2d40da98144b..0edce24f2053 100644 > > --- a/drivers/gpu/drm/rcar-du/rcar_du_encoder.c > > +++ b/drivers/gpu/drm/rcar-du/rcar_du_encoder.c > > @@ -124,11 +124,8 @@ int rcar_du_encoder_init(struct rcar_du_device *rcdu, > > } > > > > done: > > - if (ret < 0) { > > - if (encoder->name) > > - encoder->funcs->destroy(encoder); > > This is probably worth a Fixes tag, as accessing encoder->func if > drm_simple_encoder_init() has not completed might lead to a NULL > pointer dereference. But in that case encoder->name would be NULL, so encoder->funcs won't be dereferenced. And encoder->name can never be non-NULL here, as explained in the commit message, so this is dead code. I don't think it requires a Fixes: tag. > Apart from this, patch looks good > Reviewed-by: Jacopo Mondi <jacopo@jmondi.org> > > > + if (ret < 0) > > devm_kfree(rcdu->dev, renc); > > - } > > > > return ret; > > }
Hi Laurent, On 04/12/2020 22:01, Laurent Pinchart wrote: > The encoder->name field can never be non-null in the error path, as that > can only be possible after a successful call to > drm_simple_encoder_init(). Drop the cleanup. Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> > Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> > --- > drivers/gpu/drm/rcar-du/rcar_du_encoder.c | 5 +---- > 1 file changed, 1 insertion(+), 4 deletions(-) > > diff --git a/drivers/gpu/drm/rcar-du/rcar_du_encoder.c b/drivers/gpu/drm/rcar-du/rcar_du_encoder.c > index 2d40da98144b..0edce24f2053 100644 > --- a/drivers/gpu/drm/rcar-du/rcar_du_encoder.c > +++ b/drivers/gpu/drm/rcar-du/rcar_du_encoder.c > @@ -124,11 +124,8 @@ int rcar_du_encoder_init(struct rcar_du_device *rcdu, > } > > done: > - if (ret < 0) { > - if (encoder->name) > - encoder->funcs->destroy(encoder); > + if (ret < 0) > devm_kfree(rcdu->dev, renc); > - } > > return ret; > } >
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_encoder.c b/drivers/gpu/drm/rcar-du/rcar_du_encoder.c index 2d40da98144b..0edce24f2053 100644 --- a/drivers/gpu/drm/rcar-du/rcar_du_encoder.c +++ b/drivers/gpu/drm/rcar-du/rcar_du_encoder.c @@ -124,11 +124,8 @@ int rcar_du_encoder_init(struct rcar_du_device *rcdu, } done: - if (ret < 0) { - if (encoder->name) - encoder->funcs->destroy(encoder); + if (ret < 0) devm_kfree(rcdu->dev, renc); - } return ret; }
The encoder->name field can never be non-null in the error path, as that can only be possible after a successful call to drm_simple_encoder_init(). Drop the cleanup. Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> --- drivers/gpu/drm/rcar-du/rcar_du_encoder.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-)