Hi Arnd, On Fri, 24 Aug 2018 14:46:16 +0200 Arnd Bergmann <arnd@xxxxxxxx> wrote: > On Fri, Aug 24, 2018 at 10:23 AM Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote: > > > > On Fri, 24 Aug 2018 13:32:06 +1000 > > Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote: > > > > > Hi all, > > > > > > After merging the origin tree, today's linux-next build (powerpc > > > allyesconfig) produced these warnings: > > > > > > Maybe introduced by commit > > > > > > 6b7dca401cb1 ("tracing: Allow gcov profiling on only ftrace subsystem") > > > > > > I am guessing, but that is the only new thing that affects all of > > > kernel/trace ... > > > > Yes, I agree. But I just followed Documentation/dev-tools/gcov.rst > > to enable profiling in kernel/trace. Hmm, doesn't ppc64 support > > GCOV_PROFILE? (But as far as I can see, ARCH_HAS_GCOV_PROFILE_ALL > > is enabled in arch/powerpc/Kconfig) > > > > Anyway, I'll try to reproduce it. > > Thje same commit causes a link failure on ARM with a randconfig > kernel (see https://pastebin.com/KspjpyKG for the .config): OK, I confirmed that this happened with both gcc-7.3.0 and gcc-8.1.0 with your config. I also confirmed that CONFIG_GCOV_PROFILE_ALL causes same issue. (Note that CONFIG_GCOV_PROFILE_ALL depends on !CONFIG_COMPILE_TEST, so allyesconfig disables it always) Hmm, now gcov kernel itself might have a problem on arm and powerpc(on gcc-8)? Thanks, -- Masami Hiramatsu <mhiramat@xxxxxxxxxx>