[PATCH v3 8/9] powerpc/traps: Show instructions on exceptions

[Murilo Opsfelder Araujo]

Call show_instructions() in arch/powerpc/kernel/traps.c to dump
instructions at faulty location, useful to debugging.

Before this patch, an unhandled signal message looked like:

  pandafault[10524]: segfault (11) at 100007d0 nip 1000061c lr 7fffbd295100 
code 2 in pandafault[10000000+10000]

After this patch, it looks like:

  pandafault[10524]: segfault (11) at 100007d0 nip 1000061c lr 7fffbd295100 
code 2 in pandafault[10000000+10000]
  Instruction dump:
  4bfffeec 4bfffee8 3c401002 38427f00 fbe1fff8 f821ffc1 7c3f0b78 3d22fffe
  392988d0 f93f0020 e93f0020 39400048 <99490000> 39200000 7d234b78 383f0040

Signed-off-by: Murilo Opsfelder Araujo <muri...@linux.ibm.com>
---
 arch/powerpc/kernel/traps.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index e71f12bca146..b27f3f71d745 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -70,6 +70,7 @@
 #include <asm/hmi.h>
 #include <sysdev/fsl_pci.h>
 #include <asm/kprobes.h>
+#include <asm/stacktrace.h>
 
 #if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC_CORE)
 int (*__debugger)(struct pt_regs *regs) __read_mostly;
@@ -356,6 +357,8 @@ static void show_signal_msg(int signr, struct pt_regs 
*regs, int code,
        print_vma_addr(KERN_CONT " in ", regs->nip);
 
        pr_cont("\n");
+
+       show_instructions(regs);
 }
 
 void _exception_pkey(int signr, struct pt_regs *regs, int code,
-- 
2.17.1