On Fri, 24 Aug 2018 17:20:53 +0900
Masami Hiramatsu [off-list ref] wrote:

On Fri, 24 Aug 2018 13:32:06 +1000
Stephen Rothwell [off-list ref] wrote:

quoted

Hi all,

After merging the origin tree, today's linux-next build (powerpc
allyesconfig) produced these warnings:

ld: warning: orphan section `.data..LPBX1' from `kernel/trace/trace_selftest_dynamic.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/trace_kprobe_selftest.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/trace_clock.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/ftrace.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/ring_buffer.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/ring_buffer_benchmark.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/trace.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/trace_output.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/trace_seq.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/trace_stat.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/trace_printk.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/tracing_map.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/trace_sched_switch.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/trace_functions.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/trace_preemptirq.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/trace_irqsoff.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/trace_sched_wakeup.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/trace_hwlat.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/trace_nop.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/trace_stack.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/trace_functions_graph.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/blktrace.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/trace_events.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/trace_export.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/trace_syscalls.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/trace_event_perf.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/trace_events_filter.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/trace_events_trigger.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/trace_events_hist.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/bpf_trace.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/trace_kprobe.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/power-traces.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/rpm-traces.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/trace_kdb.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/trace_probe.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/trace_uprobe.o' being placed in section `.data..LPBX1'
ld: warning: orphan section `.data..LPBX1' from `kernel/trace/trace_benchmark.o' being placed in section `.data..LPBX1'

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.

gcc-7.3.0 cross build ld shows below warnings.

  MODPOST vmlinux.o
/opt/gcc-7.3.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld: warning: orphan section `.gnu.hash' from `linker stubs' being placed in section `.gnu.hash'.
  KSYM    .tmp_kallsyms1.o
/opt/gcc-7.3.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld: warning: orphan section `.gnu.hash' from `linker stubs' being placed in section `.gnu.hash'.
  KSYM    .tmp_kallsyms2.o
/opt/gcc-7.3.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld: warning: orphan section `.gnu.hash' from `linker stubs' being placed in section `.gnu.hash'.
  KSYM    .tmp_kallsyms3.o
  LD      vmlinux
/opt/gcc-7.3.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld: warning: orphan section `.gnu.hash' from `linker stubs' being placed in section `.gnu.hash'.

But it seems another warning, and I couldn't see your warnings. Could you tell me your gcc version?

Thank you,

-- 
Masami Hiramatsu [off-list ref]