On Tue, Sep 08, 2020 at 08:31:33AM +0200, Christoph Hellwig wrote: > Hi s390 maintainers, > > the base work to remove address space overrides using set_fs() has > landed in linux-next through this tree: > > https://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git/log/?h=base.set_fs > > and in addition to x86 and powerpc converted there, we have arm, arm64 > and RISC-V conversion in progress. That means s390 is the only "tier 1" > architecture still missing. Due to the special instructions for > accessing the user space address space I don't really feel like doing > the conversion myself, but it would be great if we could get s390 done > for 5.10 as well. > > The rought TODO list is: > (1) actually stop using set_fs in the zrcypt driver. I could prepare > a crude untested patch for that if it helps. Hmm.. Harald's initial implementation years ago was without set_fs(), if I remember correctly, and then he was talked into using set_fs() ;) Harald, can you take care of this part? > (2) implement the __get_user_nofault and __put_user_nofault helpers to > safely access kernel memory. These should behave like > get_user/put_user under set_fs(KERNEL_DS), but not actually > manipulate any task state to do so > (3) unselect CONFIG_SET_FS and remove all the code related to overriding > the address space(3) unselect CONFIG_SET_FS and remove all the code > related to overriding the address space limit Ok, I guess everything will have to land in vfs.git then.
