Attachment 75146 Details for Bug 59445 – Proposed fix

[patch] Proposed fix

0001-i965-Avoid-segfault-in-gen6_upload_state.patch (text/plain), 1.80 KB, created by Carl Worth on 2013-02-20 00:25:56 UTC

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Creator: Carl Worth

Created: 2013-02-20 00:25:56 UTC

Size: 1.80 KB

patch

obsolete

>From 8b64b35506ff68539e03ea3230214b7dba81dcf3 Mon Sep 17 00:00:00 2001
>From: Carl Worth <cworth@cworth.org>
>Date: Tue, 19 Feb 2013 16:21:33 -0800
>Subject: [PATCH] i965: Avoid segfault in gen6_upload_state
>
>This fixes a bug introduced in commit 258453716f001eab1288d99765213 and
>triggered whenever "rb" is NULL.
>
>Fixes bug #59445:
>
>	[SNB/IVB/HSW Bisected]Oglc draw-buffers2(advanced.blending.none) segfault
>	https://bugs.freedesktop.org/show_bug.cgi?id=59445
>---
>
>I don't know under what conditions "rb" might be NULL, but it's clear that
>it's possible and expected as there is earlier code in this function that
>checks it, (and sets rb_type specifically in that case). So if someone could
>help me write a more descriptive commit message, that would be great.
>
>Also, I notice that similar code in brw_cc.c uses a different condition here:
>
>       if (ctx->DrawBuffer->Visual.alphaBits == 0) {
>
>So an alternate fix could be to switch to something like that. Please let me
>know if one version or the other is cleaner, (and both could be made to
>match).
>
> src/mesa/drivers/dri/i965/gen6_cc.c |    2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
>diff --git a/src/mesa/drivers/dri/i965/gen6_cc.c b/src/mesa/drivers/dri/i965/gen6_cc.c
>index d32f636..7ac5d5f 100644
>--- a/src/mesa/drivers/dri/i965/gen6_cc.c
>+++ b/src/mesa/drivers/dri/i965/gen6_cc.c
>@@ -126,7 +126,7 @@ gen6_upload_blend_state(struct brw_context *brw)
>           * not read the alpha channel, but will instead use the correct
>           * implicit value for alpha.
>           */
>-         if (!_mesa_base_format_has_channel(rb->_BaseFormat, GL_TEXTURE_ALPHA_TYPE))
>+         if (rb && !_mesa_base_format_has_channel(rb->_BaseFormat, GL_TEXTURE_ALPHA_TYPE))
>          {
>             srcRGB = brw_fix_xRGB_alpha(srcRGB);
>             srcA = brw_fix_xRGB_alpha(srcA);
>-- 
>1.7.10.4
>

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Attachments on bug 59445: 75146 | 75193

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