From: Vyacheslav Cherkashin <v.cherkashin@samsung.com>
Date: Wed, 26 Aug 2015 11:19:55 +0000 (+0300)
Subject: [FIX] Move call_mm_release invocation out of atomic context
X-Git-Tag: submit/tizen_2.4/20150912.103527~21
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=refs%2Fchanges%2F57%2F46857%2F4;p=kernel%2Fswap-modules.git

[FIX] Move call_mm_release invocation out of atomic context

Change-Id: I2f3016c08a6e8c027681beb9c629e27b4f688b4f
Signed-off-by: Vyacheslav Cherkashin <v.cherkashin@samsung.com>
---

diff --git a/us_manager/helper.c b/us_manager/helper.c
index 3ba5c4f..37e4882 100644
--- a/us_manager/helper.c
+++ b/us_manager/helper.c
@@ -280,15 +280,41 @@ static void rm_uprobes_child(struct kretprobe_instance *ri,
 }
 
 
+/* FIXME: sync with stop */
+static unsigned long cp_cb(void *data)
+{
+	if (atomic_read(&stop_flag))
+		call_mm_release(current);
+
+	return 0;
+}
+
+static int pre_handler_cp(struct kprobe *p, struct pt_regs *regs)
+{
+	int ret = 0;
+
+	if (is_kthread(current))
+		goto out;
+
+	if (!atomic_read(&stop_flag))
+		goto out;
+
+	ret = set_kjump_cb(regs, cp_cb, NULL, 0);
+	if (ret < 0) {
+		pr_err("set_kjump_cp, ret=%d\n", ret);
+		ret = 0;
+	}
+out:
+	return ret;
+}
+
+
 static atomic_t copy_process_cnt = ATOMIC_INIT(0);
 
 static int entry_handler_cp(struct kretprobe_instance *ri, struct pt_regs *regs)
 {
 	atomic_inc(&copy_process_cnt);
 
-	if (atomic_read(&stop_flag))
-		call_mm_release(current);
-
 	return 0;
 }
 
@@ -315,14 +341,24 @@ static struct kretprobe cp_kretprobe = {
 	.handler = ret_handler_cp,
 };
 
+static struct kprobe cp_kprobe = {
+	.pre_handler = pre_handler_cp
+};
+
 static int register_cp(void)
 {
 	int ret;
 
-	ret = swap_register_kretprobe(&cp_kretprobe);
+
+	ret = swap_register_kprobe(&cp_kprobe);
 	if (ret)
-		printk(KERN_INFO
-		       "swap_register_kretprobe(copy_process) ret=%d!\n", ret);
+		pr_err("swap_register_kprobe(copy_process) ret=%d!\n", ret);
+
+	ret = swap_register_kretprobe(&cp_kretprobe);
+	if (ret) {
+		pr_err("swap_register_kretprobe(copy_process) ret=%d!\n", ret);
+		swap_unregister_kprobe(&cp_kprobe);
+	}
 
 	return ret;
 }
@@ -334,6 +370,7 @@ static void unregister_cp(void)
 		synchronize_sched();
 	} while (atomic_read(&copy_process_cnt));
 	swap_unregister_kretprobe_bottom(&cp_kretprobe);
+	swap_unregister_kprobe(&cp_kprobe);
 }
 
 
@@ -811,6 +848,7 @@ int once_helper(void)
 	cp_kretprobe.kp.addr = (kprobe_opcode_t *)swap_ksyms_substr(sym);
 	if (cp_kretprobe.kp.addr == NULL)
 		goto not_found;
+	cp_kprobe.addr = cp_kretprobe.kp.addr;
 
 	sym = "mm_release";
 	mr_kprobe.addr = (kprobe_opcode_t *)swap_ksyms(sym);
diff --git a/us_manager/pf/pf_group.c b/us_manager/pf/pf_group.c
index 898ad7e..0057636 100644
--- a/us_manager/pf/pf_group.c
+++ b/us_manager/pf/pf_group.c
@@ -592,13 +592,13 @@ void call_mm_release(struct task_struct *task)
 	struct sspt_proc *proc;
 
 	sspt_proc_write_lock();
-
 	proc = sspt_proc_get_by_task(task);
 	if (proc)
-		/* TODO: uninstall_proc - is not atomic context */
-		uninstall_proc(proc);
-
+		list_del(&proc->list);
 	sspt_proc_write_unlock();
+
+	if (proc)
+		uninstall_proc(proc);
 }
 
 /**