[PATCH v3 3/5] kprobes: Skip preparing optprobe if the probe is ftrace-based

[Naveen N. Rao]

From: Masami Hiramatsu <mhiramat@xxxxxxxxxx>

Skip preparing optprobe if the probe is ftrace-based, since anyway, it
must not be optimized (or already optimized by ftrace).

Tested-by: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
---
Though this patch is generic, it is needed for KPROBES_ON_FTRACE to work
on powerpc.

- Naveen


 kernel/kprobes.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 6a128f3a7ed1..406889889ce5 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -743,13 +743,20 @@ static void kill_optimized_kprobe(struct kprobe *p)
 	arch_remove_optimized_kprobe(op);
 }
 
+static inline
+void __prepare_optimized_kprobe(struct optimized_kprobe *op, struct kprobe *p)
+{
+	if (!kprobe_ftrace(p))
+		arch_prepare_optimized_kprobe(op, p);
+}
+
 /* Try to prepare optimized instructions */
 static void prepare_optimized_kprobe(struct kprobe *p)
 {
 	struct optimized_kprobe *op;
 
 	op = container_of(p, struct optimized_kprobe, kp);
-	arch_prepare_optimized_kprobe(op, p);
+	__prepare_optimized_kprobe(op, p);
 }
 
 /* Allocate new optimized_kprobe and try to prepare optimized instructions */
@@ -763,7 +770,7 @@ static struct kprobe *alloc_aggr_kprobe(struct kprobe *p)
 
 	INIT_LIST_HEAD(&op->list);
 	op->kp.addr = p->addr;
-	arch_prepare_optimized_kprobe(op, p);
+	__prepare_optimized_kprobe(op, p);
 
 	return &op->kp;
 }
-- 
2.12.1