Re: linux-next: Tree for Sep 18 (objtool)

From: Peter Zijlstra
Date: Mon Sep 23 2019 - 05:20:30 EST


On Wed, Sep 18, 2019 at 09:04:21PM -0700, Randy Dunlap wrote:
> On 9/18/19 3:10 PM, Mark Brown wrote:
> > Hi all,
> >
> > Changes since 20190917:
> >
>
> on x86_64:
>
> drivers/gpu/drm/i915/gem/i915_gem_execbuffer.o: warning: objtool: i915_gem_execbuffer2_ioctl()+0x2fb: call to gen8_canonical_addr() with UACCESS enabled

I'm thinking that comes from:

offset = gen8_canonical_addr(offset & ~UPDATE);
if (unlikely(__put_user(offset, &urelocs[r-stack].presumed_offset))) {

however, per commit 6ae865615fc4 (and 2a418cf3f5f1) the compiler really
should not be sticking gen8_canonical_addr() after __uaccess_begin().

/me puzzled...