On Wed, Sep 14, 2016 at 2:46 PM, Dave Hansen <dave.han...@linux.intel.com> wrote: > On 09/14/2016 02:35 PM, Kyle Huey wrote: >> It's not quite a plain move. To leave the existing arch_prctls only >> accessible to 64 bit callers, I added the is_32 bit and the four early >> returns for each existing ARCH_BLAH. These cases are now >> conditionally compiled out in a 32 bit kernel, so we only have to >> handle the 32 bit process on a 64 bit kernel case at runtime. > > I think it would make a lot of sense to do the move and the modification > in two patches.
Ok. > Oh, and arch_prctl() really *is* 64-bit only. I didn't realize that. > That would have been nice to call out in the changelog, too. It's > totally non-obvious. Ok. > You're going to owe some manpage updates after this too, I guess. It > says: "arch_prctl() is supported only on Linux/x86-64 for 64-bit > programs currently." Indeed. There's a patch at the end of the series (sent to LKML, but you're not directly CCd on it) with a suggested manpage patch. > FWIW, I don't think it would be horrible to leave the existing > do_arch_prctl() code in process_64.h and call it > do_64_bit_only_something_arch_prctl(), and only call in to it from the > generic do_arch_prctl(). You really have one reason for all the "if > (is_32)"'s and it would be nice to document why in one single place. Yeah, that seems like a good idea. - Kyle
