Hello,
When I try to build and run the latest mainline kernel, it Oops loading i915
module:
BUG: unable to handle page fault for address: ffffffff9edc1598
#PF: supervisor write access in kernel mode
#PF: error_code(0x0003) - permissions violation
PGD 1a20c067 P4D 1a20c067 PUD 1a20d063 PMD 8000000019e000e1
Oops: 0003 [#1] SMP PTI
The complete log is attached.
Bisection tells "x86/asm: Pin sensitive CR4 bits" (873d50d58) is the first "bad"
commit. I can revert it and also "x86/asm: Pin sensitive CR0 bits" (8dbec27a2)
to make the kernel "seems to" work.
I'm not a kernel expert so I can't tell if there is a bug in Kees' patch, or his
patch exploits a bug in i915 or module loader.
My CPU is an i3-3217u. If a kdump is helpful I'll try to gather it.
--
Xi Ruoyao <[email protected]>
School of Aerospace Science and Technology, Xidian University
Hi,
On Wed, Jul 10, 2019 at 01:44:17PM +0800, Xi Ruoyao wrote:
> Hello,
>
> When I try to build and run the latest mainline kernel, it Oops loading i915
> module:
>
> BUG: unable to handle page fault for address: ffffffff9edc1598
> #PF: supervisor write access in kernel mode
> #PF: error_code(0x0003) - permissions violation
> PGD 1a20c067 P4D 1a20c067 PUD 1a20d063 PMD 8000000019e000e1
> Oops: 0003 [#1] SMP PTI
>
> The complete log is attached.
>
> Bisection tells "x86/asm: Pin sensitive CR4 bits" (873d50d58) is the first "bad"
> commit. I can revert it and also "x86/asm: Pin sensitive CR0 bits" (8dbec27a2)
> to make the kernel "seems to" work.
>
> I'm not a kernel expert so I can't tell if there is a bug in Kees' patch, or his
> patch exploits a bug in i915 or module loader.
This seems to be a kernel bug introduced after v5.2, see
https://lore.kernel.org/lkml/CAHk-=wjh+h_-fd-gJz=wor42ZNmqq46QnB90jyfzqmKLsLFWOg@mail.gmail.com/
--
ldv