Messages in this thread | | | Date | Thu, 7 Mar 2019 13:32:00 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH 05/20] x86/uaccess/xen: Suppress SMAP warnings |
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On Thu, Mar 07, 2019 at 01:22:52PM +0100, Juergen Gross wrote: > On 07/03/2019 12:45, Peter Zijlstra wrote: > > drivers/xen/privcmd.o: warning: objtool: privcmd_ioctl()+0x1414: call to hypercall_page() with UACCESS enabled > > > > Xen needs to do HV calls with AC=1 for hysterical raisins. Make the > > warning go away. > > No, this is a hypercall with parameters passed through from user land > (Xen tools). So setting AC=1 is not related to hysterical reasons, but > to indicate that unprivileged buffers are okay here. So please change > the commit message to something like: > > Some Xen hypercalls allow parameter buffers in user land, so they need > to set AC=1. Avoid the warning for those cases.
*yuck* that's gross...
And I understood from Andrew yesterday (but perhaps I misunderstood) that the whole privcmd thing was a bit of a hack.
But sure, I'll change the message.
> > XXX: arguably we should rename ANNOTATE_NOSPEC_ALTERNATIVE to > > ANNOTATE_IGNORE_ALTERNATIVE. > > > > Cc: andrew.cooper3@citrix.com > > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> > > Mind Cc-ing the maintainers of the code you are touching in future > patches?
Sure; my bad, I forgot to ask get_maintainers about this.
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