Re: [PATCH] powerpc/8xx: Fix pinned TLBs with CONFIG_STRICT_KERNEL_RWX

From: Michael Ellerman
Date: Wed Nov 17 2021 - 06:25:42 EST


On Mon, 15 Nov 2021 09:08:36 +0100, Christophe Leroy wrote:
> As spotted and explained in commit c12ab8dbc492 ("powerpc/8xx: Fix
> Oops with STRICT_KERNEL_RWX without DEBUG_RODATA_TEST"), the selection
> of STRICT_KERNEL_RWX without selecting DEBUG_RODATA_TEST has spotted
> the lack of the DIRTY bit in the pinned kernel data TLBs.
>
> This problem should have been detected a lot earlier if things had
> been working as expected. But due to an incredible level of chance or
> mishap, this went undetected because of a set of bugs: In fact the
> DTLBs were not pinned, because instead of setting the reserve bit
> in MD_CTR, it was set in MI_CTR that is the register for ITLBs.
>
> [...]

Applied to powerpc/fixes.

[1/1] powerpc/8xx: Fix pinned TLBs with CONFIG_STRICT_KERNEL_RWX
https://git.kernel.org/powerpc/c/1e35eba4055149c578baf0318d2f2f89ea3c44a0

cheers