Attachment 82664 Details for Bug 67069 – guarantee compat_output in the range [ -1 .. num_output-1 ]

[patch] guarantee compat_output in the range [ -1 .. num_output-1 ]

0002-xfree86-guarantee-compat_output-in-the-range-1-.-num.patch (text/plain), 2.37 KB, created by vdb128 on 2013-07-19 09:05:18 UTC

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Creator: vdb128

Created: 2013-07-19 09:05:18 UTC

Size: 2.37 KB

patch

obsolete

>[PATCH] xf86Crtc.c guarantee compat_output in the range [ -1 .. num_output-1 ]
>
>The current code allows for compat_output >= num_output when
>num_output decreases to zero.  Thus hw/xfree86/modes/xf86Crtc.h
>xf86CompatOutput() may read beyond the end of the output array via
>config->output[config->compat_output].
>
>Move the compat_output update into its own if() block.  Then it is
>always updated to the last selected compat output, including
>the compat == -1 case.
>
>Signed-off-by: Servaas Vandenberghe
>---
> hw/xfree86/modes/xf86Crtc.c |   35 ++++++++++++++++++++---------------
> 1 files changed, 20 insertions(+), 15 deletions(-)
>
>diff --git a/hw/xfree86/modes/xf86Crtc.c b/hw/xfree86/modes/xf86Crtc.c
>index 1d15a46..bf4b204 100644
>--- a/hw/xfree86/modes/xf86Crtc.c
>+++ b/hw/xfree86/modes/xf86Crtc.c
>@@ -1831,22 +1831,27 @@ SetCompatOutput(xf86CrtcConfigPtr config)
>         }
>     }
> 
>-    if (compat >= 0) {
>-        if (compat != config->compat_output) {
>-            config->compat_output = compat;
>-            /* Set screen scrn->monitor info. */
>-            xf86SetDDCproperties(output->scrn, output->MonInfo);
>-        }
>-    }
>-    else if (config->compat_output >= 0 && config->compat_output < config->num_output) {
>-        /* Don't change the compat output when no valid outputs found */
>-        output = config->output[config->compat_output];
>+    if (!output) {
>+        /* All outputs are disconnected from crtc or monitor */
>+        if (config->compat_output >= 0 
>+	    && config->compat_output < config->num_output) {
>+            /* Don't change the compat output when no valid outputs found */
>+	    compat = config->compat_output;
>+	    output = config->output[compat];
>+	}
>+	else if (config->num_output > 0) {
>+	    /* All outputs are disconnected, select one to fake */
>+	    compat = 0;
>+	    output = config->output[compat];
>+	}
>     }
>-    else if (config->num_output > 0) {
>-        /* All outputs are disconnected, select one to fake */
>-        config->compat_output = 0;
>-        output = config->output[config->compat_output];
>-        xf86SetDDCproperties(output->scrn, output->MonInfo);
>+
>+    if (compat != config->compat_output) {
>+        /* compat range [ -1 .. num_output-1 ] */
>+        config->compat_output = compat;
>+        /* Set screen scrn->monitor info. */
>+        if (output)
>+	    xf86SetDDCproperties(output->scrn, output->MonInfo);
>     }
> 
>     return output;
>-- 
>1.7.4.5
>

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