[PATCH v3 6/7] powerpc: kprobes: emulate instructions on kprobe handler re-entry

[Naveen N. Rao]

On kprobe handler re-entry, try to emulate the instruction rather than
single stepping always.

Acked-by: Ananth N Mavinakayanahalli <ana...@linux.vnet.ibm.com>
Signed-off-by: Naveen N. Rao <naveen.n....@linux.vnet.ibm.com>
---
 arch/powerpc/kernel/kprobes.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index 46e8c1e03ce4..067e9863bfdf 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -276,6 +276,14 @@ int __kprobes kprobe_handler(struct pt_regs *regs)
                        kprobes_inc_nmissed_count(p);
                        prepare_singlestep(p, regs);
                        kcb->kprobe_status = KPROBE_REENTER;
+                       if (p->ainsn.boostable >= 0) {
+                               ret = try_to_emulate(p, regs);
+
+                               if (ret > 0) {
+                                       restore_previous_kprobe(kcb);
+                                       return 1;
+                               }
+                       }
                        return 1;
                } else {
                        if (*addr != BREAKPOINT_INSTRUCTION) {
-- 
2.12.1