Re: [PATCH v3 08/15] arm64: kvm: Split hyp/switch.c to VHE/nVHE

[Will Deacon]

On Thu, Jun 25, 2020 at 09:16:03AM +0100, Marc Zyngier wrote:
> On 2020-06-25 06:03, kernel test robot wrote:
> > Hi David,
> > 
> > Thank you for the patch! Perhaps something to improve:
> > 
> > [auto build test WARNING on linus/master]
> > [also build test WARNING on v5.8-rc2 next-20200624]
> > [cannot apply to kvmarm/next arm64/for-next/core arm-perf/for-next/perf]
> > [If your patch is applied to the wrong git tree, kindly drop us a note.
> > And when submitting patch, we suggest to use  as documented in
> > https://git-scm.com/docs/git-format-patch]
> > 
> > url:
> > https://github.com/0day-ci/linux/commits/David-Brazdil/Split-off-nVHE-hyp-code/20200618-203230
> > base:
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> > 1b5044021070efa3259f3e9548dc35d1eb6aa844
> > config: arm64-randconfig-r021-20200624 (attached as .config)
> > compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project
> > 8911a35180c6777188fefe0954a2451a2b91deaf)
> > reproduce (this is a W=1 build):
> >         wget
> > https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross
> > -O ~/bin/make.cross
> >         chmod +x ~/bin/make.cross
> >         # install arm64 cross compiling tool for clang build
> >         # apt-get install binutils-aarch64-linux-gnu
> >         # save the attached .config to linux build tree
> >         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross
> > ARCH=arm64
> > 
> > If you fix the issue, kindly add following tag as appropriate
> > Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > 
> > All warnings (new ones prefixed by >>):
> > 
> > > > arch/arm64/kvm/hyp/nvhe/switch.c:244:28: warning: no previous
> > > > prototype for function 'hyp_panic' [-Wmissing-prototypes]
> >    void __hyp_text __noreturn hyp_panic(struct kvm_cpu_context
> > *host_ctxt)
> 
> I really wish we could turn these warnings off. They don't add much.
> Or is there an annotation we could stick on the function (something
> like __called_from_asm_please_leave_me_alone springs to mind...)?

Agreed, I've caught myself skim-reading the kbuild robot reports now
because they're often just noise, and then having to force myself to look at
them properly when I remember. Even just something in the subject to
say "the only problems are W=1 warnings" would help. Is that possible?

Will