On 08/07/2018 03:24 AM, Joerg Roedel wrote: > The function sets the global-bit on cloned PMD entries, > which only makes sense when the permissions are identical > between the user and the kernel page-table. > > Further, only write-permissions are cleared for entry-text > and kernel-text sections, which are not writeable anyway.
I think this patch is correct, but I'd be curious if Andy remembers why we chose to clear _PAGE_RW on these things. It might have been that we were trying to say that the *entry* code shouldn't write to this stuff, regardless of whether the normal kernel can. But, either way, I agree with the logic here that Global pages must share permissions between both mappings, so feel free to add my Ack. I just want to make sure Andy doesn't remember some detail I'm forgetting.
