On Wed, Oct 03, 2018 at 05:29:34PM +0200, Daniel Vetter wrote:
On Wed, Oct 3, 2018 at 4:30 PM Eugeniy Paltsev eugeniy.paltsev@synopsys.com wrote:
On Wed, 2018-10-03 at 15:30 +0300, Ville Syrjälä wrote:
On Wed, Oct 03, 2018 at 01:36:00PM +0200, Daniel Vetter wrote:
On Wed, Oct 3, 2018 at 1:05 PM Eugeniy Paltsev Eugeniy.Paltsev@synopsys.com wrote:
Validate requested pixel format against bits_per_pixel to reject invalid formats with subcomponents length sum is greater than requested bits_per_pixel.
weston 5.0.0 with fbdev backend tries to set up an ARGB x8r8g8b8 pixel format without bits_per_pixel updating. So it can request x8r8g8b8 with 16 bpp which is obviously incorrect and should be rejected.
Cc: stable@vger.kernel.org Signed-off-by: Eugeniy Paltsev Eugeniy.Paltsev@synopsys.com
drm fbdev emulation doesn't support changing the pixel format at all. I think we should reject all such request, not just the invalid ones. Can you pls respin?
FYI I once posted a patch to tighten up the fb-helper pixel format stuff: https://patchwork.freedesktop.org/patch/203189/
Hi Daniel,
will you take Ville's patch or should I create the new one which is only related to new pixel format validation in drm_fb_helper_check_var() ?
Ville's patch isn't the bugfix we're looking for, but a draft version of what adding proper format support in drm's fbdev emulation could look like. With lots&lots of open questions.
Actually it does pretty much what you seem to be asking for. Ie. reject any attempt to change the pixel format. Not really sure how to do it much more minimally.
Hmm. Oh there is a more minimal way actually. I mistakenly remembered that fbdev clobbers info->var already before check_var(), but actually it only does that before set_par(). So I guess all we really need is to compare the fb_bitfields/bits_per_pixel/etc. between info->var and the passed in var.
Not anywhere near ready for merging, and definitely not stable backport material.
So yes, still want the minimal bugfix. -Daniel
Thanks, Daniel
drivers/gpu/drm/drm_fb_helper.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 16ec93b75dbf..4f39da07f053 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -1610,6 +1610,13 @@ int drm_fb_helper_check_var(struct fb_var_screeninfo *var, return -EINVAL; }
if ((var->green.length + var->blue.length + var->red.length +var->transp.length) > var->bits_per_pixel) {DRM_DEBUG("fb requested pixel format can't fit in %d bpp\n",var->bits_per_pixel);return -EINVAL;}switch (var->bits_per_pixel) { case 16: depth = (var->green.length == 6) ? 16 : 15;-- 2.14.4
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-- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - https://urldefense.proofpoint.com/v2/url?u=http-3A__blog.ffwll.ch&d=DwID... GmaplEUGcAEk9yPtCLdUXI&m=f12ZyEESIeavtqCUKutiZ9F6xtRFC2UUvdqnM4ywBx8&s=Vt8OX9s9ljSK6GDgbnwsF-Yd35fbBUfe8SBV2jPnVaQ&e= _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://urldefense.proofpoint.com/v2/url?u=https-3A__lists.freedesktop.org_m... riPUTkBKCrPSx67GmaplEUGcAEk9yPtCLdUXI&m=f12ZyEESIeavtqCUKutiZ9F6xtRFC2UUvdqnM4ywBx8&s=CPS8taMiYbIgXo-fxhqErOJXvO6PMTzmr-BNnGJIoy0&e=
-- Eugeniy Paltsev
-- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch