| Message ID | 20180531184858.181917-1-seanpaul@chromium.org (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Delegated to: | Andy Gross |
| Headers | show |
On 2018-05-31 11:48, Sean Paul wrote: > This patch avoids dereferencing msm_host->dev when it is NULL. > > If we find ourselves tearing down dsi before calling > (mdp4|mdp5|dpu)_kms_init(), we'll end up in a state where the dev > pointer is NULL and trying to extract priv from it will fail. > > This was introduced in a seemingly innocuous commit to ensure the > arguments to msm_gem_put_iova() are correct (even though that > function has been a stub for ~5 years). Correctness FTW! \o/ > > Fixes: b01884a286b0 drm/msm: use correct aspace pointer in > msm_gem_put_iova() > Cc: Daniel Mack <daniel@zonque.org> > Cc: Rob Clark <robdclark@gmail.com> > Signed-off-by: Sean Paul <seanpaul@chromium.org> Reviewed-by: Abhinav Kumar <abhinavk@codeaurora.org> > --- > drivers/gpu/drm/msm/dsi/dsi_host.c | 12 +++++++++++- > 1 file changed, 11 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c > b/drivers/gpu/drm/msm/dsi/dsi_host.c > index b916f464f4ec..2f1a2780658a 100644 > --- a/drivers/gpu/drm/msm/dsi/dsi_host.c > +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c > @@ -1066,8 +1066,18 @@ static int dsi_tx_buf_alloc(struct msm_dsi_host > *msm_host, int size) > static void dsi_tx_buf_free(struct msm_dsi_host *msm_host) > { > struct drm_device *dev = msm_host->dev; > - struct msm_drm_private *priv = dev->dev_private; > + struct msm_drm_private *priv; > + > + /* > + * This is possible if we're tearing down before we've had a chance > to > + * fully initialize. A very real possibility if our probe is > deferred, > + * in which case we'll hit msm_dsi_host_destroy() without having run > + * through the dsi_tx_buf_alloc(). > + */ > + if (!dev) > + return; > > + priv = dev->dev_private; > if (msm_host->tx_gem_obj) { > msm_gem_put_iova(msm_host->tx_gem_obj, priv->kms->aspace); > drm_gem_object_put_unlocked(msm_host->tx_gem_obj); -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c index b916f464f4ec..2f1a2780658a 100644 --- a/drivers/gpu/drm/msm/dsi/dsi_host.c +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c @@ -1066,8 +1066,18 @@ static int dsi_tx_buf_alloc(struct msm_dsi_host *msm_host, int size) static void dsi_tx_buf_free(struct msm_dsi_host *msm_host) { struct drm_device *dev = msm_host->dev; - struct msm_drm_private *priv = dev->dev_private; + struct msm_drm_private *priv; + + /* + * This is possible if we're tearing down before we've had a chance to + * fully initialize. A very real possibility if our probe is deferred, + * in which case we'll hit msm_dsi_host_destroy() without having run + * through the dsi_tx_buf_alloc(). + */ + if (!dev) + return; + priv = dev->dev_private; if (msm_host->tx_gem_obj) { msm_gem_put_iova(msm_host->tx_gem_obj, priv->kms->aspace); drm_gem_object_put_unlocked(msm_host->tx_gem_obj);
This patch avoids dereferencing msm_host->dev when it is NULL. If we find ourselves tearing down dsi before calling (mdp4|mdp5|dpu)_kms_init(), we'll end up in a state where the dev pointer is NULL and trying to extract priv from it will fail. This was introduced in a seemingly innocuous commit to ensure the arguments to msm_gem_put_iova() are correct (even though that function has been a stub for ~5 years). Correctness FTW! \o/ Fixes: b01884a286b0 drm/msm: use correct aspace pointer in msm_gem_put_iova() Cc: Daniel Mack <daniel@zonque.org> Cc: Rob Clark <robdclark@gmail.com> Signed-off-by: Sean Paul <seanpaul@chromium.org> --- drivers/gpu/drm/msm/dsi/dsi_host.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-)