| Message ID | 20200524233900.25598-1-chris@chris-wilson.co.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/i915/display: Fix early deref of 'dsb' | expand |
On 25-05-2020 05:09, Chris Wilson wrote: > drivers/gpu/drm/i915/display/intel_dsb.c:177 intel_dsb_reg_write() warn: variable dereferenced before check 'dsb' (see line 175) > > Fixes: afeda4f3b1c8 ("drm/i915/dsb: Pre allocate and late cleanup of cmd buffer") > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> > Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> > Cc: Animesh Manna <animesh.manna@intel.com> > Cc: Uma Shankar <uma.shankar@intel.com> Thanks Chris for catching. Reviewed-by: Animesh Manna <animesh.manna@intel.com> > --- > drivers/gpu/drm/i915/display/intel_dsb.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_dsb.c b/drivers/gpu/drm/i915/display/intel_dsb.c > index 475106e91fa7..24e6d63e2d47 100644 > --- a/drivers/gpu/drm/i915/display/intel_dsb.c > +++ b/drivers/gpu/drm/i915/display/intel_dsb.c > @@ -169,15 +169,17 @@ void intel_dsb_indexed_reg_write(const struct intel_crtc_state *crtc_state, > void intel_dsb_reg_write(const struct intel_crtc_state *crtc_state, > i915_reg_t reg, u32 val) > { > - struct intel_dsb *dsb = crtc_state->dsb; > struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc); > struct drm_i915_private *dev_priv = to_i915(crtc->base.dev); > - u32 *buf = dsb->cmd_buf; > + struct intel_dsb *dsb; > + u32 *buf; > > + dsb = crtc_state->dsb; > if (!dsb) { > intel_de_write(dev_priv, reg, val); > return; > } > + > buf = dsb->cmd_buf; > if (drm_WARN_ON(&dev_priv->drm, dsb->free_pos >= DSB_BUF_SIZE)) { > drm_dbg_kms(&dev_priv->drm, "DSB buffer overflow\n");
diff --git a/drivers/gpu/drm/i915/display/intel_dsb.c b/drivers/gpu/drm/i915/display/intel_dsb.c index 475106e91fa7..24e6d63e2d47 100644 --- a/drivers/gpu/drm/i915/display/intel_dsb.c +++ b/drivers/gpu/drm/i915/display/intel_dsb.c @@ -169,15 +169,17 @@ void intel_dsb_indexed_reg_write(const struct intel_crtc_state *crtc_state, void intel_dsb_reg_write(const struct intel_crtc_state *crtc_state, i915_reg_t reg, u32 val) { - struct intel_dsb *dsb = crtc_state->dsb; struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc); struct drm_i915_private *dev_priv = to_i915(crtc->base.dev); - u32 *buf = dsb->cmd_buf; + struct intel_dsb *dsb; + u32 *buf; + dsb = crtc_state->dsb; if (!dsb) { intel_de_write(dev_priv, reg, val); return; } + buf = dsb->cmd_buf; if (drm_WARN_ON(&dev_priv->drm, dsb->free_pos >= DSB_BUF_SIZE)) { drm_dbg_kms(&dev_priv->drm, "DSB buffer overflow\n");
drivers/gpu/drm/i915/display/intel_dsb.c:177 intel_dsb_reg_write() warn: variable dereferenced before check 'dsb' (see line 175) Fixes: afeda4f3b1c8 ("drm/i915/dsb: Pre allocate and late cleanup of cmd buffer") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Animesh Manna <animesh.manna@intel.com> Cc: Uma Shankar <uma.shankar@intel.com> --- drivers/gpu/drm/i915/display/intel_dsb.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)