[BISECTED] kexec regression on PowerBook G4

[Aaro Koskinen]

Hi,

On Thu, May 23, 2019 at 08:58:11PM +0200, Christophe Leroy wrote:
> Le 23/05/2019 à 19:27, Aaro Koskinen a écrit :
> >On Thu, May 23, 2019 at 07:33:38AM +0200, Christophe Leroy wrote:
> >>Ok, the Oops confirms that the error is due to executing the kexec control
> >>code which is located outside the kernel text area.
> >>
> >>My yesterday's proposed change doesn't work because on book3S/32, NX
> >>protection is based on setting segments to NX, and using IBATs for kernel
> >>text.
> >>
> >>Can you try the patch I sent out a few minutes ago ?
> >>(https://patchwork.ozlabs.org/patch/1103827/)
> >
> >It now crashes with "BUG: Unable to handle kernel instruction fetch"
> >and the faulting address is 0xef13a000.
> 
> Ok.
> 
> Can you try with both changes at the same time, ie the mtsrin(...) and the
> change_page_attr() ?
> 
> I suspect that allthough the HW is not able to check EXEC flag, the SW will
> check it before loading the hash entry.

Unfortunately still no luck... The crash is pretty much the same with both
changes.

A.