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