[PATCH 2/2] [BUGFIX] kprobes/mips: Fix to check double free of insn slot

[Masami Hiramatsu]

Fix to check double free of insn_slot at arch_remove_kprobe
as other arches do.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Daney <ddaney@caviumnetworks.com>
Cc: Maneesh Soni <manesoni@cisco.com>
Cc: Victor Kamensky <kamensky@cisco.com>
Cc: linux-mips@linux-mips.org
---
 arch/mips/kernel/kprobes.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/mips/kernel/kprobes.c b/arch/mips/kernel/kprobes.c
index 12bc4eb..1f8187a 100644
--- a/arch/mips/kernel/kprobes.c
+++ b/arch/mips/kernel/kprobes.c
@@ -207,7 +207,10 @@ void __kprobes arch_disarm_kprobe(struct kprobe *p)
 
 void __kprobes arch_remove_kprobe(struct kprobe *p)
 {
-	free_insn_slot(p->ainsn.insn, 0);
+	if (p->ainsn.insn) {
+		free_insn_slot(p->ainsn.insn, 0);
+		p->ainsn.insn = NULL;
+	}
 }
 
 static void save_previous_kprobe(struct kprobe_ctlblk *kcb)