[PATCH] powerpc/64s: Fix build failures with CONFIG_NMI_IPI=n

[PATCH] powerpc/64s: Fix build failures with CONFIG_NMI_IPI=n

[Michael Ellerman]

I broke the build when CONFIG_NMI_IPI=n with my recent commit to add
arch_trigger_cpumask_backtrace(), eg:

  stacktrace.c:(.text+0x1b0): undefined reference to `.smp_send_safe_nmi_ipi'

We should rework the CONFIG symbols here in future to avoid these
double barrelled ifdefs but for now they fix the build.

Fixes: 5cc05910f26e ("powerpc/64s: Wire up arch_trigger_cpumask_backtrace()")
Reported-by: Christophe LEROY <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/include/asm/nmi.h   | 2 +-
 arch/powerpc/kernel/stacktrace.c | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/include/asm/nmi.h b/arch/powerpc/include/asm/nmi.h
index 0f571e0ebca1..bd9ba8defd72 100644
--- a/arch/powerpc/include/asm/nmi.h
+++ b/arch/powerpc/include/asm/nmi.h
@@ -8,7 +8,7 @@ extern void arch_touch_nmi_watchdog(void);
 static inline void arch_touch_nmi_watchdog(void) {}
 #endif
 
-#if defined(CONFIG_PPC_BOOK3S_64) && defined(CONFIG_STACKTRACE)
+#if defined(CONFIG_NMI_IPI) && defined(CONFIG_STACKTRACE)
 extern void arch_trigger_cpumask_backtrace(const cpumask_t *mask,
 					   bool exclude_self);
 #define arch_trigger_cpumask_backtrace arch_trigger_cpumask_backtrace
diff --git a/arch/powerpc/kernel/stacktrace.c b/arch/powerpc/kernel/stacktrace.c
index 07e97f289c52..e2c50b55138f 100644
--- a/arch/powerpc/kernel/stacktrace.c
+++ b/arch/powerpc/kernel/stacktrace.c
@@ -196,7 +196,7 @@ save_stack_trace_tsk_reliable(struct task_struct *tsk,
 EXPORT_SYMBOL_GPL(save_stack_trace_tsk_reliable);
 #endif /* CONFIG_HAVE_RELIABLE_STACKTRACE */
 
-#ifdef CONFIG_PPC_BOOK3S_64
+#if defined(CONFIG_PPC_BOOK3S_64) && defined(CONFIG_NMI_IPI)
 static void handle_backtrace_ipi(struct pt_regs *regs)
 {
 	nmi_cpu_backtrace(regs);
@@ -242,4 +242,4 @@ void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
 {
 	nmi_trigger_cpumask_backtrace(mask, exclude_self, raise_backtrace_ipi);
 }
-#endif /* CONFIG_PPC64 */
+#endif /* defined(CONFIG_PPC_BOOK3S_64) && defined(CONFIG_NMI_IPI) */
-- 
2.14.1

Re: powerpc/64s: Fix build failures with CONFIG_NMI_IPI=n

[Michael Ellerman]

On Tue, 2018-06-19 at 23:04:54 UTC, Michael Ellerman wrote:
> I broke the build when CONFIG_NMI_IPI=n with my recent commit to add
> arch_trigger_cpumask_backtrace(), eg:
> 
>   stacktrace.c:(.text+0x1b0): undefined reference to `.smp_send_safe_nmi_ipi'
> 
> We should rework the CONFIG symbols here in future to avoid these
> double barrelled ifdefs but for now they fix the build.
> 
> Fixes: 5cc05910f26e ("powerpc/64s: Wire up arch_trigger_cpumask_backtrace()")
> Reported-by: Christophe LEROY <christophe.leroy@c-s.fr>
> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Applied to powerpc fixes.

https://git.kernel.org/powerpc/c/e08ecba17b72aeb01859601bc242a5

cheers