| Date | Mon, 15 Dec 2014 18:03:10 +0800 | Subject | Re: [PATCH 00/18] uaccess: fix sparse warning on get_user for bitwise types | From | "LF.Tan" <> |
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On Mon, Dec 15, 2014 at 12:51 AM, Michael S. Tsirkin <mst@redhat.com> wrote: > At the moment, if p and x are both tagged as bitwise types, > get_user(x, p) produces a sparse warning on many architectures. > This is because *p on these architectures is loaded into long > (typically using asm), then cast back to typeof(*p). > > When typeof(*p) is a bitwise type (which is uncommon), such a cast needs > __force, otherwise sparse produces a warning. > > Some architectures already have the __force tag, add it > where it's missing. > > Specificlly, vhost wants to read bitwise types from userspace using get_user. > At the moment this triggers sparse errors, since the value is passed through an > integer. > > For now, I worked around this by converting vhost code to access_ok + > __get_user, but that's not robust, I'd like to switch to get_user for 3.19. > > I tested this on x86 only so far. Since it's just adding __force, should be > trivially safe everywhere? > > Please review, and consider for 3.19. > > Who can merge this? Arnd? Hi Michael
FYI, there is new arch (arch/nios2) in 3.19. Is your patchset include the fix for it? Thanks.
Regards Ley Foon
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