Re: arch/powerpc/kernel/stacktrace.c:171:9: error: implicit declaration of function 'nmi_cpu_backtrace'

[Peter Zijlstra <peterz@infradead.org>]

On Fri, Jan 14, 2022 at 06:13:37AM +0800, kernel test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   fb3b0673b7d5b477ed104949450cd511337ba3c6
> commit: 1614b2b11fab29dd4ff31ebba9d266961f5af69e arch: Make ARCH_STACKWALK independent of STACKTRACE
> date:   5 weeks ago
> config: powerpc64-randconfig-r025-20220113 (https://download.01.org/0day-ci/archive/20220114/202201140631.ZuSwa9QF-lkp@intel.com/config)
> compiler: powerpc64-linux-gcc (GCC) 11.2.0
> 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
>         # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1614b2b11fab29dd4ff31ebba9d266961f5af69e
>         git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
>         git fetch --no-tags linus master
>         git checkout 1614b2b11fab29dd4ff31ebba9d266961f5af69e
>         # save the config file to linux build tree
>         mkdir build_dir
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=powerpc SHELL=/bin/bash
> 
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
> 
> All errors (new ones prefixed by >>):
> 
>    arch/powerpc/kernel/stacktrace.c: In function 'handle_backtrace_ipi':
> >> arch/powerpc/kernel/stacktrace.c:171:9: error: implicit declaration of function 'nmi_cpu_backtrace' [-Werror=implicit-function-declaration]
>      171 |         nmi_cpu_backtrace(regs);
>          |         ^~~~~~~~~~~~~~~~~
>    arch/powerpc/kernel/stacktrace.c: At top level:
>    arch/powerpc/kernel/stacktrace.c:224:6: warning: no previous prototype for 'arch_trigger_cpumask_backtrace' [-Wmissing-prototypes]
>      224 | void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
>          |      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>    arch/powerpc/kernel/stacktrace.c: In function 'arch_trigger_cpumask_backtrace':
> >> arch/powerpc/kernel/stacktrace.c:226:9: error: implicit declaration of function 'nmi_trigger_cpumask_backtrace'; did you mean 'arch_trigger_cpumask_backtrace'? [-Werror=implicit-function-declaration]
>      226 |         nmi_trigger_cpumask_backtrace(mask, exclude_self, raise_backtrace_ipi);
>          |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>          |         arch_trigger_cpumask_backtrace
>    cc1: some warnings being treated as errors

I suppose this ought to cure things...

diff --git a/arch/powerpc/kernel/stacktrace.c b/arch/powerpc/kernel/stacktrace.c
index a2443d61728e..bde1aaedeb72 100644
--- a/arch/powerpc/kernel/stacktrace.c
+++ b/arch/powerpc/kernel/stacktrace.c
@@ -165,7 +165,7 @@ int __no_sanitize_address arch_stack_walk_reliable(stack_trace_consume_fn consum
 	return 0;
 }
 
-#if defined(CONFIG_PPC_BOOK3S_64) && defined(CONFIG_NMI_IPI)
+#if defined(CONFIG_PPC_BOOK3S_64) && defined(CONFIG_NMI_IPI) && defined(CONFIG_STACKTRACE)
 static void handle_backtrace_ipi(struct pt_regs *regs)
 {
 	nmi_cpu_backtrace(regs);