| Message ID | 1341747464-1772-5-git-send-email-Julia.Lawall@lip6.fr (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Dear Julia, Am Sonntag, den 08.07.2012, 13:37 +0200 schrieb Julia Lawall: > From: Julia Lawall <Julia.Lawall@lip6.fr> > > If list_for_each_entry, etc complete a traversal of the list, the iterator > variable ends up pointing to an address at an offset from the list head, > and not a meaningful structure. Thus this value should not be used after > the end of the iterator. > > In the first two cases, a a break is added after the switch; the break in s,a a,a, > the switch would jump out of the switch, but not out of the complete > iteration. > > In the first case, the null test on connector is removed, because the > iterator variable of list_for_each_entry is never null. > > In the third case, entry->base.crtc.fb is not a meaningful value. What > seems to be intended is crtc->fb, which gets the information from the last > element of the list. maybe three separate patches would have been better? > These problems were found using Coccinelle (http://coccinelle.lip6.fr/). I always liked your example Coccinelle code snippets. Could you add them again to your commit messages? That would be awesome! > Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> > > --- > drivers/gpu/drm/gma500/mdfld_intel_display.c | 4 +--- > drivers/gpu/drm/gma500/oaktrail_crtc.c | 1 + > drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c | 2 +- > 3 files changed, 3 insertions(+), 4 deletions(-) > > diff --git a/drivers/gpu/drm/gma500/mdfld_intel_display.c b/drivers/gpu/drm/gma500/mdfld_intel_display.c > index 3f3cd61..fc1ced0 100644 > --- a/drivers/gpu/drm/gma500/mdfld_intel_display.c > +++ b/drivers/gpu/drm/gma500/mdfld_intel_display.c > @@ -755,9 +755,6 @@ static int mdfld_crtc_mode_set(struct drm_crtc *crtc, > sizeof(struct drm_display_mode)); > > list_for_each_entry(connector, &mode_config->connector_list, head) { > - if (!connector) > - continue; > - > encoder = connector->encoder; > > if (!encoder) > @@ -779,6 +776,7 @@ static int mdfld_crtc_mode_set(struct drm_crtc *crtc, > is_hdmi = true; > break; > } > + break; > } > > /* Disable the VGA plane that we never use */ > diff --git a/drivers/gpu/drm/gma500/oaktrail_crtc.c b/drivers/gpu/drm/gma500/oaktrail_crtc.c > index f821c83..4b2172e 100644 > --- a/drivers/gpu/drm/gma500/oaktrail_crtc.c > +++ b/drivers/gpu/drm/gma500/oaktrail_crtc.c > @@ -329,6 +329,7 @@ static int oaktrail_crtc_mode_set(struct drm_crtc *crtc, > is_mipi = true; > break; > } > + break; > } > > /* Disable the VGA plane that we never use */ > diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c b/drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c > index 070fb23..634611a 100644 > --- a/drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c > +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c > @@ -93,7 +93,7 @@ static int vmw_ldu_commit_list(struct vmw_private *dev_priv) > > if (crtc == NULL) > return 0; > - fb = entry->base.crtc.fb; > + fb = crtc->fb; > > return vmw_kms_write_svga(dev_priv, w, h, fb->pitches[0], > fb->bits_per_pixel, fb->depth); Acked-by: Paul Menzel <paulepanter@users.sourceforge.net> Thanks, Paul
On Sun, 8 Jul 2012, Paul Menzel wrote: > Dear Julia, > > > Am Sonntag, den 08.07.2012, 13:37 +0200 schrieb Julia Lawall: >> From: Julia Lawall <Julia.Lawall@lip6.fr> >> >> If list_for_each_entry, etc complete a traversal of the list, the iterator >> variable ends up pointing to an address at an offset from the list head, >> and not a meaningful structure. Thus this value should not be used after >> the end of the iterator. >> >> In the first two cases, a a break is added after the switch; the break in > > s,a a,a, Thanks. >> the switch would jump out of the switch, but not out of the complete >> iteration. >> >> In the first case, the null test on connector is removed, because the >> iterator variable of list_for_each_entry is never null. >> >> In the third case, entry->base.crtc.fb is not a meaningful value. What >> seems to be intended is crtc->fb, which gets the information from the last >> element of the list. > > maybe three separate patches would have been better? OK, I wasn't sure what would be best. I'll send three patches now. >> These problems were found using Coccinelle (http://coccinelle.lip6.fr/). > > I always liked your example Coccinelle code snippets. Could you add them > again to your commit messages? That would be awesome! Sure. I didn't include it because there was a 0/7 message that has the complete semantic patch. julia >> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> >> >> --- >> drivers/gpu/drm/gma500/mdfld_intel_display.c | 4 +--- >> drivers/gpu/drm/gma500/oaktrail_crtc.c | 1 + >> drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c | 2 +- >> 3 files changed, 3 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/gpu/drm/gma500/mdfld_intel_display.c b/drivers/gpu/drm/gma500/mdfld_intel_display.c >> index 3f3cd61..fc1ced0 100644 >> --- a/drivers/gpu/drm/gma500/mdfld_intel_display.c >> +++ b/drivers/gpu/drm/gma500/mdfld_intel_display.c >> @@ -755,9 +755,6 @@ static int mdfld_crtc_mode_set(struct drm_crtc *crtc, >> sizeof(struct drm_display_mode)); >> >> list_for_each_entry(connector, &mode_config->connector_list, head) { >> - if (!connector) >> - continue; >> - >> encoder = connector->encoder; >> >> if (!encoder) >> @@ -779,6 +776,7 @@ static int mdfld_crtc_mode_set(struct drm_crtc *crtc, >> is_hdmi = true; >> break; >> } >> + break; >> } >> >> /* Disable the VGA plane that we never use */ >> diff --git a/drivers/gpu/drm/gma500/oaktrail_crtc.c b/drivers/gpu/drm/gma500/oaktrail_crtc.c >> index f821c83..4b2172e 100644 >> --- a/drivers/gpu/drm/gma500/oaktrail_crtc.c >> +++ b/drivers/gpu/drm/gma500/oaktrail_crtc.c >> @@ -329,6 +329,7 @@ static int oaktrail_crtc_mode_set(struct drm_crtc *crtc, >> is_mipi = true; >> break; >> } >> + break; >> } >> >> /* Disable the VGA plane that we never use */ >> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c b/drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c >> index 070fb23..634611a 100644 >> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c >> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c >> @@ -93,7 +93,7 @@ static int vmw_ldu_commit_list(struct vmw_private *dev_priv) >> >> if (crtc == NULL) >> return 0; >> - fb = entry->base.crtc.fb; >> + fb = crtc->fb; >> >> return vmw_kms_write_svga(dev_priv, w, h, fb->pitches[0], >> fb->bits_per_pixel, fb->depth); > > Acked-by: Paul Menzel <paulepanter@users.sourceforge.net> > > > Thanks, > > Paul >
diff --git a/drivers/gpu/drm/gma500/mdfld_intel_display.c b/drivers/gpu/drm/gma500/mdfld_intel_display.c index 3f3cd61..fc1ced0 100644 --- a/drivers/gpu/drm/gma500/mdfld_intel_display.c +++ b/drivers/gpu/drm/gma500/mdfld_intel_display.c @@ -755,9 +755,6 @@ static int mdfld_crtc_mode_set(struct drm_crtc *crtc, sizeof(struct drm_display_mode)); list_for_each_entry(connector, &mode_config->connector_list, head) { - if (!connector) - continue; - encoder = connector->encoder; if (!encoder) @@ -779,6 +776,7 @@ static int mdfld_crtc_mode_set(struct drm_crtc *crtc, is_hdmi = true; break; } + break; } /* Disable the VGA plane that we never use */ diff --git a/drivers/gpu/drm/gma500/oaktrail_crtc.c b/drivers/gpu/drm/gma500/oaktrail_crtc.c index f821c83..4b2172e 100644 --- a/drivers/gpu/drm/gma500/oaktrail_crtc.c +++ b/drivers/gpu/drm/gma500/oaktrail_crtc.c @@ -329,6 +329,7 @@ static int oaktrail_crtc_mode_set(struct drm_crtc *crtc, is_mipi = true; break; } + break; } /* Disable the VGA plane that we never use */ diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c b/drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c index 070fb23..634611a 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c @@ -93,7 +93,7 @@ static int vmw_ldu_commit_list(struct vmw_private *dev_priv) if (crtc == NULL) return 0; - fb = entry->base.crtc.fb; + fb = crtc->fb; return vmw_kms_write_svga(dev_priv, w, h, fb->pitches[0], fb->bits_per_pixel, fb->depth);