sparc64: Fix SMP bootup with CONFIG_STACK_DEBUG or ftrace.

Based upon a report by Meelis Roos.

Any function call can try to access the current
thread register via the _mcount hooks when the kernel
is built with -pg (via ftrace or STACK_DEBUG).

That can't be setup properly very early on during
the bootup of other cpus for sun4u and some early
sun4v systems.

So add notrace markers to these specific functions, so
that _mcount doesn't get invoked too early.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 1 deletions

diff --git a/arch/sparc64/kernel/traps.c b/arch/sparc64/kernel/traps.c
index 3d924121c796..c824df13f589 100644
--- a/arch/sparc64/kernel/traps.c
+++ b/arch/sparc64/kernel/traps.c
@@ -10,6 +10,7 @@
 
 #include <linux/module.h>
 #include <linux/sched.h>
+#include <linux/linkage.h>
 #include <linux/kernel.h>
 #include <linux/signal.h>
 #include <linux/smp.h>
@@ -2453,7 +2454,7 @@ struct trap_per_cpu trap_block[NR_CPUS];
 /* This can get invoked before sched_init() so play it super safe
  * and use hard_smp_processor_id().
  */
-void init_cur_cpu_trap(struct thread_info *t)
+void notrace init_cur_cpu_trap(struct thread_info *t)
 {
         int cpu = hard_smp_processor_id();
         struct trap_per_cpu *p = &trap_block[cpu];