Comment 34 for bug 281610

I'm using the evdev driver, so I get a different backtrace:

0: X [0x100ae894]
1: X(xf86SigHandler+0xc8) [0x100ae824]
2: [0x100344]
3: [0x28]
4: X(NewInputDeviceRequest+0x504) [0x100c7d24]
5: X [0x10089080]
6: X [0x10089560]
7: X [0x10088130]
8: X [0x10146f94]
9: X(WaitForSomething+0x7e8) [0x101478ec]
10: X(Dispatch+0xac) [0x1004c5e8]
11: X(main+0x5b4) [0x10028b8c]
12: /lib/libc.so.6 [0xf906704]
13: /lib/libc.so.6 [0xf9068c0]

(Unfortunately, I can't seem to get more information about the crash with gdb, it just hangs instead of giving me a prompt... Steve, are you seeing this as well? Anyway, I've narrowed it down using debugging output to CheckMotion() crashing because pSprite is NULL.)

But I think the key is really

[dix] cannot find pointer to pair with. This is a bug.

I've bisected this to xserver commit 1e24e7b9df3d02350c7ea18e9379e87fe4d00026 ('Xi: remove configure/query device property calls.'), but I can't see what in there could cause the symptoms we're seeing; also obviously it doesn't happen on x86... So it could be related to endianness or char being unsigned by default, or maybe just some kind of latent memory corruption issue that happens not to affect x86. (I think I've ruled out a compiler optimization bug by rebuilding everything affected by this change with -O0).

Peter, any suggestions for narrowing down why it's unable to find a pointer for pairing?