On Fri, Sep 25, 2020 at 01:29:20PM +0300, Jarkko Sakkinen wrote: > On Fri, Sep 25, 2020 at 09:00:56AM +0200, Ard Biesheuvel wrote: > > On Fri, 25 Sep 2020 at 07:56, Jarkko Sakkinen > > <jarkko.sakkinen@xxxxxxxxxxxxxxx> wrote: > > > > > > On Tue, Sep 22, 2020 at 11:41:28AM +0200, Ard Biesheuvel wrote: > > > > The TPM event log is provided to the OS by the firmware, by loading > > > > it into an area in memory and passing the physical address via a node > > > > in the device tree. > > > > > > > > Currently, we use __va() to access the memory via the kernel's linear > > > > map: however, it is not guaranteed that the linear map covers this > > > > particular address, as we may be running under HIGHMEM on a 32-bit > > > > architecture, or running firmware that uses a memory type for the > > > > event log that is omitted from the linear map (such as EfiReserved). > > > > > > Makes perfect sense to the level that I wonder if this should have a > > > fixes tag and/or needs to be backported to the stable kernels? > > > > > > > AIUI, the code was written specifically for ppc64, which is a > > non-highmem, non-EFI architecture. However, when we start reusing this > > driver for ARM, this issue could pop up. > > > > The code itself has been refactored a couple of times, so I think it > > will require different versions of the patch for different generations > > of stable kernels. > > > > So perhaps just add Cc: <stable@xxxxxxxxxxxxxxx>, and wait and see how > > far back it applies cleanly? > > Yeah, I think I'll cc it with some note before the diffstat. > > I'm thinking to cap it to only 5.x kernels (at least first) unless it is > dead easy to backport below that. I have this vauge recollection of pointing at this before and being told that it had to be __va for some PPC reason? Do check with the PPC people first, I see none on the CC list. Jason
