Messages in this thread | | | Subject | Re: 2.6.11.8 + UML/x86_64 (2.6.12-rc3+) = oops | From | Andi Kleen <> | Date | Sun, 08 May 2005 17:15:36 +0200 |
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Antoine Martin <antoine@nagafix.co.uk> writes:
>> (..) >> That is a wrmsr to 0x00000000c0000102 (KERNEL_GS_BASE), the code >> is trying to write 0x0000c8e816000002 into it. That is a non canonical >> address, which causes the GPF. >> >> The strange thing is that the kernel should have rejected it in >> the first place. The code to allow user space to set kernel gs >> checks for the address being > TASK_SIZE and TASK_SIZE is 0x800000000000. >> It should have rejected it in the first place. >> >> Are you sure you did not apply any strange UML related patches >> to the host kernel? Maybe those are buggy. > The only extra patch applied on top of what is on the web page (as per > Jeff's instructions) is the mconsole-exec patch, and AFAIK it wouldn't > affect the code above. > > Alexander Nyberg is also experiencing crashes, aren't you?
Ok, the bug is found now. It is a kernel bug that it allows to set non canonical addresses in 64bit segment registers through ptrace.
But even if I fixed that then it will not help you run UML, because UML needs to set correct addresses of course, not illegal ones.
I will submit a patch later for the crash problem.
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