From: Vyacheslav Cherkashin <v.cherkashin@samsung.com>
Date: Fri, 15 Apr 2016 12:15:43 +0000 (+0300)
Subject: [FIX] sspt_ip usage after removing
X-Git-Tag: submit/tizen/20161124.145503~40^2~8
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=87e1ca7a74d7e04c72164c18785414b19046efdf;p=kernel%2Fswap-modules.git

[FIX] sspt_ip usage after removing

Change-Id: I5d897ad063a31ac02e15ae4ccb9b8aca54e1fae7
Signed-off-by: Vyacheslav Cherkashin <v.cherkashin@samsung.com>
---

diff --git a/us_manager/img/img_file.c b/us_manager/img/img_file.c
index 377fdfb..b90ef0a 100644
--- a/us_manager/img/img_file.c
+++ b/us_manager/img/img_file.c
@@ -68,7 +68,8 @@ static void img_file_free(struct img_file *file)
 
 	list_for_each_entry_safe(ip, tmp, &file->ips.head, list) {
 		img_del_ip_by_list(ip);
-		img_ip_free(ip);
+		img_ip_clean(ip);
+		img_ip_put(ip);
 	}
 
 	kfree(file);
@@ -174,7 +175,8 @@ int img_file_del_ip(struct img_file *file, unsigned long addr,
 	img_del_ip_by_list(ip);
 	mutex_unlock(&file->ips.mtx);
 
-	img_ip_free(ip);
+	img_ip_clean(ip);
+	img_ip_put(ip);
 
 	return 0;
 }
diff --git a/us_manager/img/img_ip.c b/us_manager/img/img_ip.c
index 3d99b8d..368ddb4 100644
--- a/us_manager/img/img_ip.c
+++ b/us_manager/img/img_ip.c
@@ -25,6 +25,7 @@
 
 #include "img_ip.h"
 #include <us_manager/probes/use_probes.h>
+#include <us_manager/sspt/sspt.h>
 #include <us_manager/sspt/sspt_ip.h>
 #include <linux/slab.h>
 
@@ -44,32 +45,68 @@ struct img_ip *img_ip_create(unsigned long addr, struct probe_desc *pd)
 		return NULL;
 
 	INIT_LIST_HEAD(&ip->list);
-	INIT_LIST_HEAD(&ip->sspt_head);
+	kref_init(&ip->ref);
+	mutex_init(&ip->sspt.mtx);
+	INIT_LIST_HEAD(&ip->sspt.head);
 	ip->addr = addr;
 	ip->desc = pd;
 
 	return ip;
 }
 
-/**
- * @brief Remove img_ip struct
- *
- * @param ip remove object
- * @return Void
- */
-void img_ip_free(struct img_ip *ip)
+static void img_ip_release(struct kref *ref)
+{
+	struct img_ip *ip = container_of(ref, struct img_ip, ref);
+
+	WARN_ON(!list_empty(&ip->sspt.head));
+	kfree(ip);
+}
+
+void img_ip_clean(struct img_ip *ip)
 {
 	struct sspt_ip *p, *n;
+	LIST_HEAD(head);
 
-	list_for_each_entry_safe(p, n, &ip->sspt_head, img_list) {
-		list_del_init(&p->img_list);
-		p->img_ip = NULL;
-		list_del(&p->list);
-		probe_info_unregister(p->desc->type, p, 1);
-		sspt_ip_free(p);
+	mutex_lock(&ip->sspt.mtx);
+	list_for_each_entry_safe(p, n, &ip->sspt.head, img_list) {
+		if (sspt_page_is_installed_ip(p->page, p))
+			sspt_unregister_usprobe(NULL, p, US_UNREGS_PROBE);
+
+		sspt_ip_get(p);
+		list_move(&p->img_list, &head);
 	}
+	mutex_unlock(&ip->sspt.mtx);
 
-	kfree(ip);
+	list_for_each_entry_safe(p, n, &head, img_list) {
+		sspt_ip_clean(p);
+		sspt_ip_put(p);
+	}
+}
+
+void img_ip_get(struct img_ip *ip)
+{
+	kref_get(&ip->ref);
+}
+
+void img_ip_put(struct img_ip *ip)
+{
+	kref_put(&ip->ref, img_ip_release);
+}
+
+void img_ip_add_ip(struct img_ip *ip, struct sspt_ip *sspt_ip)
+{
+	sspt_ip->img_ip = ip;
+	list_add(&sspt_ip->img_list, &ip->sspt.head);
+}
+
+void img_ip_lock(struct img_ip *ip)
+{
+	mutex_lock(&ip->sspt.mtx);
+}
+
+void img_ip_unlock(struct img_ip *ip)
+{
+	mutex_unlock(&ip->sspt.mtx);
 }
 
 /**
diff --git a/us_manager/img/img_ip.h b/us_manager/img/img_ip.h
index fa57531..14c2bd3 100644
--- a/us_manager/img/img_ip.h
+++ b/us_manager/img/img_ip.h
@@ -27,7 +27,11 @@
 #define _IMG_IP_H
 
 #include <linux/types.h>
-#include <us_manager/probes/probes.h>
+#include <linux/kref.h>
+
+
+struct sspt_ip;
+struct probe_desc;
 
 /**
  * @struct img_ip
@@ -37,15 +41,26 @@ struct img_ip {
 	/* img_file */
 	struct list_head list;		/**< List for img_file */
 
+	struct kref ref;
+
 	/* sspt_ip */
-	struct list_head sspt_head;	/**< Head for sspt_ip */
+	struct {
+		struct mutex mtx;
+		struct list_head head;
+	} sspt;
 
 	unsigned long addr;		/**< Function address */
 	struct probe_desc *desc;	/**< Probe info */
 };
 
 struct img_ip *img_ip_create(unsigned long addr, struct probe_desc *info);
-void img_ip_free(struct img_ip *ip);
+void img_ip_clean(struct img_ip *ip);
+void img_ip_get(struct img_ip *ip);
+void img_ip_put(struct img_ip *ip);
+
+void img_ip_add_ip(struct img_ip *ip, struct sspt_ip *sspt_ip);
+void img_ip_lock(struct img_ip *ip);
+void img_ip_unlock(struct img_ip *ip);
 
 /* debug */
 void img_ip_print(struct img_ip *ip);
diff --git a/us_manager/sspt/sspt_file.c b/us_manager/sspt/sspt_file.c
index c55da68..0190898 100644
--- a/us_manager/sspt/sspt_file.c
+++ b/us_manager/sspt/sspt_file.c
@@ -124,7 +124,8 @@ void sspt_file_free(struct sspt_file *file)
 		head = htable_head_by_idx(file, i);
 		swap_hlist_for_each_entry_safe(page, p, n, head, hlist) {
 			hlist_del(&page->hlist);
-			sspt_page_free(page);
+			sspt_page_clean(page);
+			sspt_page_put(page);
 		}
 	}
 	up_write(&file->htable.sem);
@@ -223,12 +224,10 @@ void sspt_file_add_ip(struct sspt_file *file, struct img_ip *img_ip)
 	if (!page)
 		return;
 
-	/* FIXME: delete ip */
-	ip = sspt_ip_create(img_ip);
+	ip = sspt_ip_create(img_ip, page);
 	if (!ip)
 		return;
 
-	sspt_add_ip(page, ip);
 	probe_info_init(ip->desc->type, ip);
 }
 
diff --git a/us_manager/sspt/sspt_ip.c b/us_manager/sspt/sspt_ip.c
index b69cd21..0f0b4ff 100644
--- a/us_manager/sspt/sspt_ip.c
+++ b/us_manager/sspt/sspt_ip.c
@@ -23,6 +23,7 @@
  */
 
 #include <linux/slab.h>
+#include <linux/list.h>
 #include <linux/module.h>
 #include "sspt_ip.h"
 #include "sspt_page.h"
@@ -39,7 +40,7 @@
  * @param page Pointer to the parent sspt_page struct
  * @return Pointer to the created us_ip struct
  */
-struct sspt_ip *sspt_ip_create(struct img_ip *img_ip)
+struct sspt_ip *sspt_ip_create(struct img_ip *img_ip, struct sspt_page *page)
 {
 	struct sspt_ip *ip;
 
@@ -50,24 +51,69 @@ struct sspt_ip *sspt_ip_create(struct img_ip *img_ip)
 	memset(ip, 0, sizeof(*ip));
 	INIT_LIST_HEAD(&ip->list);
 	INIT_LIST_HEAD(&ip->img_list);
-	ip->offset = img_ip->addr;
+	ip->offset = img_ip->addr & ~PAGE_MASK;
 	ip->desc = img_ip->desc;
-	ip->img_ip = img_ip;
-	list_add(&ip->img_list, &img_ip->sspt_head);
+	atomic_set(&ip->usage, 2);	/* for 'img_ip' and 'page' */
+
+	/* add to img_ip list */
+	img_ip_get(img_ip);
+	img_ip_lock(img_ip);
+	img_ip_add_ip(img_ip, ip);
+	img_ip_unlock(img_ip);
+
+	/* add to page list */
+	sspt_page_get(page);
+	sspt_page_lock(page);
+	sspt_page_add_ip(page, ip);
+	sspt_page_unlock(page);
 
 	return ip;
 }
 
-/**
- * @brief Remove us_ip struct
- *
- * @param ip remove object
- * @return Void
- */
-void sspt_ip_free(struct sspt_ip *ip)
+static void sspt_ip_free(struct sspt_ip *ip)
 {
-	if (!list_empty(&ip->img_list))
-		list_del(&ip->img_list);
+	WARN_ON(!list_empty(&ip->list) || !list_empty(&ip->img_list));
 
 	kfree(ip);
 }
+
+void sspt_ip_get(struct sspt_ip *ip)
+{
+	atomic_inc(&ip->usage);
+}
+
+void sspt_ip_put(struct sspt_ip *ip)
+{
+	if (atomic_dec_and_test(&ip->usage))
+		sspt_ip_free(ip);
+}
+
+void sspt_ip_clean(struct sspt_ip *ip)
+{
+	bool put_page = false;
+	bool put_ip = false;
+
+	/* remove from page */
+	sspt_page_lock(ip->page);
+	if (!list_empty(&ip->list)) {
+		list_del_init(&ip->list);
+		put_page = true;
+	}
+	sspt_page_unlock(ip->page);
+	if (put_page) {
+		sspt_page_put(ip->page);
+		sspt_ip_put(ip);
+	}
+
+	/* remove from img_ip */
+	img_ip_lock(ip->img_ip);
+	if (!list_empty(&ip->img_list)) {
+		list_del_init(&ip->img_list);
+		put_ip = true;
+	}
+	img_ip_unlock(ip->img_ip);
+	if (put_ip) {
+		img_ip_put(ip->img_ip);
+		sspt_ip_put(ip);
+	}
+}
diff --git a/us_manager/sspt/sspt_ip.h b/us_manager/sspt/sspt_ip.h
index 14954b8..226173e 100644
--- a/us_manager/sspt/sspt_ip.h
+++ b/us_manager/sspt/sspt_ip.h
@@ -25,6 +25,7 @@
  */
 
 #include <linux/list.h>
+#include <linux/atomic.h>
 #include <uprobe/swap_uprobes.h>
 #include <us_manager/probes/probes.h>
 
@@ -43,6 +44,8 @@ struct sspt_ip {
 	struct img_ip *img_ip;      /**< Pointer on the img_ip (parent) */
 	struct list_head img_list;  /**< For img_ip */
 
+	atomic_t usage;
+
 	unsigned long orig_addr;    /**< Function address */
 	unsigned long offset;       /**< Page offset */
 
@@ -55,8 +58,10 @@ struct sspt_ip {
 };
 
 
-struct sspt_ip *sspt_ip_create(struct img_ip *img_ip);
-void sspt_ip_free(struct sspt_ip *ip);
+struct sspt_ip *sspt_ip_create(struct img_ip *img_ip, struct sspt_page *page);
+void sspt_ip_clean(struct sspt_ip *ip);
+void sspt_ip_get(struct sspt_ip *ip);
+void sspt_ip_put(struct sspt_ip *ip);
 
 
 #endif /* _SSPT_IP */
diff --git a/us_manager/sspt/sspt_page.c b/us_manager/sspt/sspt_page.c
index 476996b..6eed534 100644
--- a/us_manager/sspt/sspt_page.c
+++ b/us_manager/sspt/sspt_page.c
@@ -46,42 +46,54 @@ struct sspt_page *sspt_page_create(unsigned long offset)
 		INIT_LIST_HEAD(&obj->ip_list.not_inst);
 		obj->offset = offset;
 		obj->file = NULL;
+		kref_init(&obj->ref);
 	}
 
 	return obj;
 }
 
-/**
- * @brief Remove sspt_page struct
- *
- * @param page remove object
- * @return Void
- */
-void sspt_page_free(struct sspt_page *page)
+void sspt_page_clean(struct sspt_page *page)
 {
 	struct sspt_ip *ip, *n;
+	LIST_HEAD(head);
 
+	mutex_lock(&page->ip_list.mtx);
+	WARN_ON(!list_empty(&page->ip_list.inst));
 	list_for_each_entry_safe(ip, n, &page->ip_list.inst, list) {
-		list_del(&ip->list);
-		sspt_ip_free(ip);
+		sspt_ip_get(ip);
+		list_move(&ip->list, &head);
 	}
 
 	list_for_each_entry_safe(ip, n, &page->ip_list.not_inst, list) {
-		list_del(&ip->list);
-		sspt_ip_free(ip);
+		sspt_ip_get(ip);
+		list_move(&ip->list, &head);
+	}
+	mutex_unlock(&page->ip_list.mtx);
+
+	list_for_each_entry_safe(ip, n, &head, list) {
+		sspt_ip_clean(ip);
+		sspt_ip_put(ip);
 	}
+}
+
+static void sspt_page_release(struct kref *ref)
+{
+	struct sspt_page *page = container_of(ref, struct sspt_page, ref);
+
+	WARN_ON(!list_empty(&page->ip_list.inst) ||
+		!list_empty(&page->ip_list.not_inst));
 
 	kfree(page);
 }
 
-static void sspt_list_add_ip(struct sspt_page *page, struct sspt_ip *ip)
+void sspt_page_get(struct sspt_page *page)
 {
-	list_add(&ip->list, &page->ip_list.not_inst);
+	kref_get(&page->ref);
 }
 
-static void sspt_list_del_ip(struct sspt_ip *ip)
+void sspt_page_put(struct sspt_page *page)
 {
-	list_del(&ip->list);
+	kref_put(&page->ref, sspt_page_release);
 }
 
 /**
@@ -91,23 +103,20 @@ static void sspt_list_del_ip(struct sspt_ip *ip)
  * @param ip Pointer to the us_ip struct
  * @return Void
  */
-void sspt_add_ip(struct sspt_page *page, struct sspt_ip *ip)
+void sspt_page_add_ip(struct sspt_page *page, struct sspt_ip *ip)
 {
-	ip->offset &= ~PAGE_MASK;
 	ip->page = page;
-	sspt_list_add_ip(page, ip);
+	list_add(&ip->list, &page->ip_list.not_inst);
 }
 
-/**
- * @brief Del instruction pointer from sspt_page
- *
- * @param ip Pointer to the us_ip struct
- * @return Void
- */
-void sspt_del_ip(struct sspt_ip *ip)
+void sspt_page_lock(struct sspt_page *page)
+{
+	mutex_lock(&page->ip_list.mtx);
+}
+
+void sspt_page_unlock(struct sspt_page *page)
 {
-	sspt_list_del_ip(ip);
-	sspt_ip_free(ip);
+	mutex_unlock(&page->ip_list.mtx);
 }
 
 /**
@@ -121,6 +130,18 @@ bool sspt_page_is_installed(struct sspt_page *page)
 	return !list_empty(&page->ip_list.inst);
 }
 
+bool sspt_page_is_installed_ip(struct sspt_page *page, struct sspt_ip *ip)
+{
+	struct sspt_ip *p;
+
+	list_for_each_entry(p, &page->ip_list.inst, list) {
+		if (p == ip)
+			return true;
+	}
+
+	return false;
+}
+
 /**
  * @brief Install probes on the page
  *
@@ -132,6 +153,7 @@ int sspt_register_page(struct sspt_page *page, struct sspt_file *file)
 {
 	int err = 0;
 	struct sspt_ip *ip, *n;
+	LIST_HEAD(not_inst_head);
 
 	mutex_lock(&page->ip_list.mtx);
 	if (list_empty(&page->ip_list.not_inst)) {
@@ -150,8 +172,8 @@ int sspt_register_page(struct sspt_page *page, struct sspt_file *file)
 
 		err = sspt_register_usprobe(ip);
 		if (err) {
-			list_del(&ip->list);
-			sspt_ip_free(ip);
+			sspt_ip_get(ip);
+			list_move(&ip->list, &not_inst_head);
 			continue;
 		}
 	}
@@ -161,6 +183,11 @@ int sspt_register_page(struct sspt_page *page, struct sspt_file *file)
 unlock:
 	mutex_unlock(&page->ip_list.mtx);
 
+	list_for_each_entry_safe(ip, n, &not_inst_head, list) {
+		sspt_ip_clean(ip);
+		sspt_ip_put(ip);
+	}
+
 	return 0;
 }
 
diff --git a/us_manager/sspt/sspt_page.h b/us_manager/sspt/sspt_page.h
index 1ed8a67..bf7fa89 100644
--- a/us_manager/sspt/sspt_page.h
+++ b/us_manager/sspt/sspt_page.h
@@ -26,6 +26,7 @@
 
 #include <linux/types.h>
 #include <linux/mutex.h>
+#include <linux/kref.h>
 
 struct sspt_ip;
 struct sspt_file;
@@ -49,13 +50,19 @@ struct sspt_page {
 	} ip_list;
 
 	unsigned long offset;			/**< File offset */
+
+	struct kref ref;
 };
 
 struct sspt_page *sspt_page_create(unsigned long offset);
-void sspt_page_free(struct sspt_page *page);
+void sspt_page_clean(struct sspt_page *page);
+void sspt_page_get(struct sspt_page *page);
+void sspt_page_put(struct sspt_page *page);
 
-void sspt_add_ip(struct sspt_page *page, struct sspt_ip *ip);
-void sspt_del_ip(struct sspt_ip *ip);
+bool sspt_page_is_installed_ip(struct sspt_page *page, struct sspt_ip *ip);
+void sspt_page_add_ip(struct sspt_page *page, struct sspt_ip *ip);
+void sspt_page_lock(struct sspt_page *page);
+void sspt_page_unlock(struct sspt_page *page);
 
 bool sspt_page_is_installed(struct sspt_page *page);