| 1 |
Patching the Linux kernel to disable the sys_iopl and sys_ioperm system |
| 2 |
calls (e.g., by setting CONFIG_GRKERNSEC_IO=y) used to cause the xserver |
| 3 |
to fail to start even with KMS-enabled drivers -- at least in the case |
| 4 |
of the in-kernel radeon driver. |
| 5 |
|
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I don't know what recent changes are responsible but for whatever |
| 7 |
reason, X now works fine without the aforementioned system calls on the |
| 8 |
same hardware. |
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|
| 10 |
Unfortunately, it doesn't work on another machine using the Intel driver |
| 11 |
and same X/kernel versions. It fails with the error: "failed to set |
| 12 |
IOPL". Does anyone know why the Intel, but not Radeon driver, might be |
| 13 |
failing? I don't have any particular knowledge of the inner-workings of |
| 14 |
the graphics stack |
| 15 |
|
| 16 |
A quick search turned up the following on the X mailing list: "Fix |
| 17 |
initialization when iopl is forbidden": |
| 18 |
http://lists.x.org/archives/xorg-devel/2012-September/033656.html |
| 19 |
|
| 20 |
http://cgit.freedesktop.org/~ajax/xserver/patch/?id=d88fb00d791c2b19cf9dd244276838aba3a6b442 |
| 21 |
|
| 22 |
The above patch applies to x11-base/xorg-server-1.13.2 (with a fuzz |
| 23 |
factor of 2 but it's good) but I haven't had a chance to test it on the |
| 24 |
affected machine. I'll post a followup if it fixes the problem. |
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|
| 26 |
Dave |
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