Messages in this thread | | | Date | Tue, 3 Nov 2009 14:59:14 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH] fbdev: Wrong test on unsigned in fb_set_user_cmap()? |
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On Tue, 20 Oct 2009 21:30:38 +0200 Roel Kluin <roel.kluin@gmail.com> wrote:
> struct fb_cmap_user member start is unsigned. > > Signed-off-by: Roel Kluin <roel.kluin@gmail.com> > --- > Is this required? > > diff --git a/drivers/video/fbcmap.c b/drivers/video/fbcmap.c > index f53b9f1..f46f05f 100644 > --- a/drivers/video/fbcmap.c > +++ b/drivers/video/fbcmap.c > @@ -266,7 +266,7 @@ int fb_set_user_cmap(struct fb_cmap_user *cmap, struct fb_info *info) > rc = -ENODEV; > goto out; > } > - if (cmap->start < 0 || (!info->fbops->fb_setcolreg && > + if ((int)cmap->start < 0 || (!info->fbops->fb_setcolreg && > !info->fbops->fb_setcmap)) { > rc = -EINVAL; > goto out1;
I think the test _is_ needed, as `start' is passed in direct from userspace, via do_fb_ioctl():FBIOPUTCMAP.
However fb_set_user_cmap() calls fb_set_cmap() which also checks `start', only this time it does it correctly.
So overall the code is OK and the check which you've identified is unneeded.
In fact, all of
if (cmap->start < 0 || (!info->fbops->fb_setcolreg && !info->fbops->fb_setcmap)) { rc = -EINVAL; goto out1; }
can be removed.
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