Need help with debugging a directx9 game crashing

[Qian Hong]

Hi Ken,

On Thu, Jul 25, 2013 at 2:33 AM, Ken Thomases <ken at codeweavers.com> wrote:
> Hmm.  You may need to mark the dummy array as volatile to prevent it from being optimized away.  Worth trying.  You might also increase the size of the array.

You are right, thanks! Increasing the size of the array helps, the
minimum working size I found is 588, I've attach the patch and the
backtrace to Bug 34125.

In my hack, I let:
+    char dummy[588];
+    memset(dummy, 0x55, sizeof(dummy));
+    dummy[4] = 0x88;
+    dummy[5] = 0x77;
+    dummy[6] = 0x66;
+    dummy[7] = 0x55;
/* why 584 doesn't work? */

And I get a crashing like:
Unhandled exception: page fault on read access to 0x55667788 in 32-bit code

I've also hack wined3d/directx.c in a similar way, the minimum size is 592:
+    char dummy[592];
+    memset(dummy, 0xee, sizeof(dummy));
+    dummy[8] = 0xdd;
+    dummy[9] = 0xcc;
+    dummy[10] = 0xbb;
+    dummy[11] = 0xaa;
/* why 584 and 588 doesn't work ? */
The crashing is like:
Unhandled exception: page fault on read access to 0xaabbccdd in 32-bit code

When combining the  d3d9 hack and the wined3d hack, the behavior is
the same to d3d9 hack only.

I'll see how far I can get from here, also I'm open to any suggestion
and appreciate to any help!

Thanks again.


-- 
Regards,
Qian Hong

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