Re: [PATCH resend] x86/purgatory: Make sure we fail the build if purgatory.ro has missing symbols

[Arvind Sankar]

On Wed, Mar 11, 2020 at 09:49:54PM +0100, Borislav Petkov wrote:
> On Sat, Feb 29, 2020 at 07:12:57PM +0100, Hans de Goede wrote:
> > Hi,
> > 
> > On 2/29/20 6:16 PM, kbuild test robot wrote:
> > > Hi Hans,
> > > 
> > > I love your patch! Yet something to improve:
> > > 
> > > [auto build test ERROR on tip/x86/core]
> > > [also build test ERROR on v5.6-rc3 next-20200228]
> > > [cannot apply to tip/auto-latest]
> > > [if your patch is applied to the wrong git tree, please drop us a note to help
> > > improve the system. BTW, we also suggest to use '--base' option to specify the
> > > base tree in git format-patch, please see https://stackoverflow.com/a/37406982]
> > > 
> > > url:    https://github.com/0day-ci/linux/commits/Hans-de-Goede/x86-purgatory-Make-sure-we-fail-the-build-if-purgatory-ro-has-missing-symbols/20200223-040035
> > > base:   https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 248ed51048c40d36728e70914e38bffd7821da57
> > > config: x86_64-randconfig-s1-20200229 (attached as .config)
> > > compiler: gcc-4.9 (Debian 4.9.2-10+deb8u1) 4.9.2
> > > reproduce:
> > >          # save the attached .config to linux build tree
> > >          make ARCH=x86_64
> > > 
> > > If you fix the issue, kindly add following tag
> > > Reported-by: kbuild test robot <lkp@xxxxxxxxx>
> > > 
> > > All errors (new ones prefixed by >>):
> > > 
> > >     ld: arch/x86/purgatory/purgatory.ro: in function `kstrtoull':
> > > > > (.text+0x2b0e): undefined reference to `ftrace_likely_update'
> > 
> > AFAICT this is the patch working as intended and pointing out an actual issue
> > with the purgatory code. Which shows that we really should get this
> > patch merged...
> 
> ... and break the build? I don't think so.
> 
> I know, it would fail silently now but I don't recall anyone complaining
> about it. So it was a don't care so far.
> 
> IOW, first this ftrace_likely_update thing needs to be sorted out and
> then this merged.
> 
> Thx.
> 
> -- 
> Regards/Gruss,
>     Boris.
> 
> https://people.kernel.org/tglx/notes-about-netiquette

Hans, I think adding -DDISABLE_BRANCH_PROFILING to PURGATORY_CFLAGS
might fix this.

Thanks.