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

From: Hans de Goede
Date: Wed Mar 11 2020 - 17:25:42 EST


HI,

On 3/11/20 10:20 PM, Arvind Sankar wrote:
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.

Yes I was just looking into doing that myself, I agree that that
should fix this. I will mail out a new patch-series with that as
preparation patch soon.

Regards,

Hans