| Message ID | 20170921210424.GA21951@Haneen (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Sep 21, 2017 at 11:16:44PM +0200, Julia Lawall wrote: > > > On Thu, 21 Sep 2017, Haneen Mohammed wrote: > > > Remove obsolete comment which was initially added in 2008 to annotate > > that idr_find() was used before idr_remove() since idr_remove() didn't > > use to return feedback. The comment now is irrelevant with > > commit f6cd7daecff5 ("drm: Release driver references to handle before > > making it available again"). > > Why did you send it again? > > julia > I forgot to include the dri-devel mailing list for the first patch. Haneen > > > > Signed-off-by: Haneen Mohammed <hamohammed.sa@gmail.com> > > --- > > drivers/gpu/drm/drm_gem.c | 9 --------- > > 1 file changed, 9 deletions(-) > > > > diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c > > index c55f338..b9bddaa 100644 > > --- a/drivers/gpu/drm/drm_gem.c > > +++ b/drivers/gpu/drm/drm_gem.c > > @@ -282,15 +282,6 @@ drm_gem_handle_delete(struct drm_file *filp, u32 handle) > > { > > struct drm_gem_object *obj; > > > > - /* This is gross. The idr system doesn't let us try a delete and > > - * return an error code. It just spews if you fail at deleting. > > - * So, we have to grab a lock around finding the object and then > > - * doing the delete on it and dropping the refcount, or the user > > - * could race us to double-decrement the refcount and cause a > > - * use-after-free later. Given the frequency of our handle lookups, > > - * we may want to use ida for number allocation and a hash table > > - * for the pointers, anyway. > > - */ > > spin_lock(&filp->table_lock); > > > > /* Check if we currently have a reference on the object */ > > -- > > 2.7.4 > > > > -- > > You received this message because you are subscribed to the Google Groups "outreachy-kernel" group. > > To unsubscribe from this group and stop receiving emails from it, send an email to outreachy-kernel+unsubscribe@googlegroups.com. > > To post to this group, send email to outreachy-kernel@googlegroups.com. > > To view this discussion on the web visit https://groups.google.com/d/msgid/outreachy-kernel/20170921210424.GA21951%40Haneen. > > For more options, visit https://groups.google.com/d/optout. > >
On Thu, Sep 21, 2017 at 03:04:24PM -0600, Haneen Mohammed wrote: > Remove obsolete comment which was initially added in 2008 to annotate > that idr_find() was used before idr_remove() since idr_remove() didn't > use to return feedback. The comment now is irrelevant with > commit f6cd7daecff5 ("drm: Release driver references to handle before > making it available again"). Personally I'd have added a lot more of the research story you've detailed in the private mails, just to show the work you've done. But the terse version is ok too ofc. > Signed-off-by: Haneen Mohammed <hamohammed.sa@gmail.com> Applied to drm-misc-next, thanks. -Daniel > --- > drivers/gpu/drm/drm_gem.c | 9 --------- > 1 file changed, 9 deletions(-) > > diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c > index c55f338..b9bddaa 100644 > --- a/drivers/gpu/drm/drm_gem.c > +++ b/drivers/gpu/drm/drm_gem.c > @@ -282,15 +282,6 @@ drm_gem_handle_delete(struct drm_file *filp, u32 handle) > { > struct drm_gem_object *obj; > > - /* This is gross. The idr system doesn't let us try a delete and > - * return an error code. It just spews if you fail at deleting. > - * So, we have to grab a lock around finding the object and then > - * doing the delete on it and dropping the refcount, or the user > - * could race us to double-decrement the refcount and cause a > - * use-after-free later. Given the frequency of our handle lookups, > - * we may want to use ida for number allocation and a hash table > - * for the pointers, anyway. > - */ > spin_lock(&filp->table_lock); > > /* Check if we currently have a reference on the object */ > -- > 2.7.4 > > -- > You received this message because you are subscribed to the Google Groups "outreachy-kernel" group. > To unsubscribe from this group and stop receiving emails from it, send an email to outreachy-kernel+unsubscribe@googlegroups.com. > To post to this group, send email to outreachy-kernel@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/outreachy-kernel/20170921210424.GA21951%40Haneen. > For more options, visit https://groups.google.com/d/optout.
On Tue, Sep 26, 2017 at 07:24:38AM +0200, Daniel Vetter wrote: > On Thu, Sep 21, 2017 at 03:04:24PM -0600, Haneen Mohammed wrote: > > Remove obsolete comment which was initially added in 2008 to annotate > > that idr_find() was used before idr_remove() since idr_remove() didn't > > use to return feedback. The comment now is irrelevant with > > commit f6cd7daecff5 ("drm: Release driver references to handle before > > making it available again"). > > Personally I'd have added a lot more of the research story you've detailed > in the private mails, just to show the work you've done. But the terse > version is ok too ofc. > > > Signed-off-by: Haneen Mohammed <hamohammed.sa@gmail.com> > > Applied to drm-misc-next, thanks. > -Daniel > My bad, I was afraid to add too much details as I always read commit message should be concise that I then ended up with too little. I will try next time to add the necessary information. Thank you! Haneen > > --- > > drivers/gpu/drm/drm_gem.c | 9 --------- > > 1 file changed, 9 deletions(-) > > > > diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c > > index c55f338..b9bddaa 100644 > > --- a/drivers/gpu/drm/drm_gem.c > > +++ b/drivers/gpu/drm/drm_gem.c > > @@ -282,15 +282,6 @@ drm_gem_handle_delete(struct drm_file *filp, u32 handle) > > { > > struct drm_gem_object *obj; > > > > - /* This is gross. The idr system doesn't let us try a delete and > > - * return an error code. It just spews if you fail at deleting. > > - * So, we have to grab a lock around finding the object and then > > - * doing the delete on it and dropping the refcount, or the user > > - * could race us to double-decrement the refcount and cause a > > - * use-after-free later. Given the frequency of our handle lookups, > > - * we may want to use ida for number allocation and a hash table > > - * for the pointers, anyway. > > - */ > > spin_lock(&filp->table_lock); > > > > /* Check if we currently have a reference on the object */ > > -- > > 2.7.4 > > > > -- > > You received this message because you are subscribed to the Google Groups "outreachy-kernel" group. > > To unsubscribe from this group and stop receiving emails from it, send an email to outreachy-kernel+unsubscribe@googlegroups.com. > > To post to this group, send email to outreachy-kernel@googlegroups.com. > > To view this discussion on the web visit https://groups.google.com/d/msgid/outreachy-kernel/20170921210424.GA21951%40Haneen. > > For more options, visit https://groups.google.com/d/optout. > > -- > Daniel Vetter > Software Engineer, Intel Corporation > http://blog.ffwll.ch
diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index c55f338..b9bddaa 100644 --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -282,15 +282,6 @@ drm_gem_handle_delete(struct drm_file *filp, u32 handle) { struct drm_gem_object *obj; - /* This is gross. The idr system doesn't let us try a delete and - * return an error code. It just spews if you fail at deleting. - * So, we have to grab a lock around finding the object and then - * doing the delete on it and dropping the refcount, or the user - * could race us to double-decrement the refcount and cause a - * use-after-free later. Given the frequency of our handle lookups, - * we may want to use ida for number allocation and a hash table - * for the pointers, anyway. - */ spin_lock(&filp->table_lock); /* Check if we currently have a reference on the object */
Remove obsolete comment which was initially added in 2008 to annotate that idr_find() was used before idr_remove() since idr_remove() didn't use to return feedback. The comment now is irrelevant with commit f6cd7daecff5 ("drm: Release driver references to handle before making it available again"). Signed-off-by: Haneen Mohammed <hamohammed.sa@gmail.com> --- drivers/gpu/drm/drm_gem.c | 9 --------- 1 file changed, 9 deletions(-)