From: Vasiliy Ulyanov <v.ulyanov@samsung.com>
Date: Wed, 26 Aug 2015 11:32:29 +0000 (+0300)
Subject: [FIX] Use stop_machine to disarm kretprobe_instance
X-Git-Tag: submit/tizen_2.4/20150912.103527~20
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=refs%2Fchanges%2F58%2F46858%2F4;p=kernel%2Fswap-modules.git

[FIX] Use stop_machine to disarm kretprobe_instance

Change-Id: Id1fb5f1ad1a13dc76b465bb08d42f55a4886b713
Signed-off-by: Vyacheslav Cherkashin <v.cherkashin@samsung.com>
---

diff --git a/kprobe/swap_kprobes.c b/kprobe/swap_kprobes.c
index 1a08278..ce18b00 100644
--- a/kprobe/swap_kprobes.c
+++ b/kprobe/swap_kprobes.c
@@ -40,6 +40,7 @@
 #include <linux/module.h>
 #include <linux/mm.h>
 #include <linux/pagemap.h>
+#include <linux/stop_machine.h>
 
 #include <ksyms/ksyms.h>
 #include <master/swap_initializer.h>
@@ -930,6 +931,33 @@ static void swap_disarm_krp(struct kretprobe *rp)
 	}
 }
 
+
+struct unreg_krp_args {
+	struct kretprobe **rps;
+	size_t size;
+	int rp_disarm;
+};
+
+static int __swap_unregister_kretprobes_top(void *data)
+{
+	struct unreg_krp_args *args = data;
+	struct kretprobe **rps = args->rps;
+	size_t size = args->size;
+	int rp_disarm = args->rp_disarm;
+	unsigned long flags;
+	const size_t end = ((size_t) 0) - 1;
+
+	spin_lock_irqsave(&kretprobe_lock, flags);
+	for (--size; size != end; --size) {
+		swap_unregister_kprobe(&rps[size]->kp);
+		if (rp_disarm)
+			swap_disarm_krp(rps[size]);
+	}
+	spin_unlock_irqrestore(&kretprobe_lock, flags);
+
+	return 0;
+}
+
 /**
  * @brief Kretprobes unregister top. Unregisters kprobes.
  *
@@ -941,16 +969,22 @@ static void swap_disarm_krp(struct kretprobe *rp)
 void swap_unregister_kretprobes_top(struct kretprobe **rps, size_t size,
 				   int rp_disarm)
 {
-	unsigned long flags;
-	const size_t end = ((size_t) 0) - 1;
-
-	spin_lock_irqsave(&kretprobe_lock, flags);
-	for (--size; size != end; --size) {
-		swap_unregister_kprobe(&rps[size]->kp);
-		if (rp_disarm)
-			swap_disarm_krp(rps[size]);
+	struct unreg_krp_args args = {
+		.rps = rps,
+		.size = size,
+		.rp_disarm = rp_disarm,
+	};
+
+	if (rp_disarm) {
+		int ret;
+
+		ret = stop_machine(__swap_unregister_kretprobes_top,
+				   &args, NULL);
+		if (ret)
+			pr_err("%s failed (%d)\n", __func__, ret);
+	} else {
+		__swap_unregister_kretprobes_top(&args);
 	}
-	spin_unlock_irqrestore(&kretprobe_lock, flags);
 }
 EXPORT_SYMBOL_GPL(swap_unregister_kretprobes_top);
 
diff --git a/task_data/task_data.c b/task_data/task_data.c
index 51f1578..085e016 100644
--- a/task_data/task_data.c
+++ b/task_data/task_data.c
@@ -161,7 +161,6 @@ static int __task_data_exit(void *data)
 	struct task_data *td;
 
 	swap_unregister_kprobe(&do_exit_probe);
-	swap_unregister_kretprobe(&copy_process_rp);
 
 	do_each_thread(g, t) {
 		td = __td(t);
@@ -185,14 +184,15 @@ static void task_data_stop(void)
 {
 	int ret;
 
+	swap_unregister_kretprobe(&copy_process_rp);
+
 	/* stop_machine: the same here */
-	ret = stop_machine(__task_data_exit, &copy_process_rp, NULL);
+	ret = stop_machine(__task_data_exit, NULL, NULL);
 	if (ret) {
 		printk(TD_PREFIX "task data cleanup failed: %d\n", ret);
 		/* something went wrong: at least make sure we unregister
 		 * all the installed probes */
 		swap_unregister_kprobe(&do_exit_probe);
-		swap_unregister_kretprobe(&copy_process_rp);
 	}
 }