From d571378ac7182ea3b797e382b55e61deb3259c73 Mon Sep 17 00:00:00 2001
From: gaoyang3513 <gaoyang3513@163.com>
Date: Wed, 17 Apr 2024 15:57:40 +0800
Subject: [PATCH] =?UTF-8?q?[Mod]=20=E6=94=AF=E6=8C=81Mutex=20=E6=AD=BB?=
 =?UTF-8?q?=E9=94=81=E6=B5=8B=E8=AF=95?=
MIME-Version: 1.0
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Content-Transfer-Encoding: 8bit

---
 arch/arm64/configs/lubancat2_defconfig |  2 +
 gaoyang3513/testings/pstore/test_ps.c  | 60 +++++++++++++++++++++++++-
 2 files changed, 61 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/configs/lubancat2_defconfig b/arch/arm64/configs/lubancat2_defconfig
index e99604956835..8476e02af0a5 100644
--- a/arch/arm64/configs/lubancat2_defconfig
+++ b/arch/arm64/configs/lubancat2_defconfig
@@ -800,3 +800,5 @@ CONFIG_BLK_DEV_IO_TRACE=y
 CONFIG_LKDTM=y
 
 CONFIG_TESTING_PSTORE=m
+CONFIG_LOCK_STAT=y
+CONFIG_PROVE_LOCKING=y
\ No newline at end of file
diff --git a/gaoyang3513/testings/pstore/test_ps.c b/gaoyang3513/testings/pstore/test_ps.c
index 7be00dd9dcb1..855798027613 100644
--- a/gaoyang3513/testings/pstore/test_ps.c
+++ b/gaoyang3513/testings/pstore/test_ps.c
@@ -4,6 +4,8 @@
 #include <linux/delay.h>
 #include <linux/vmalloc.h>
 #include <linux/rcupdate.h>
+#include <linux/kthread.h>
+#include <linux/mutex.h>
 
 static unsigned int test_type;
 module_param(test_type, uint, 0400);
@@ -61,6 +63,56 @@ static void trigger_rcu(void)
     call_rcu(&test_rcu_head, bad_rcu_callback);
 }
 
+static int is_ready_thread1, is_ready_thread2;
+static struct task_struct *thread1;
+static struct task_struct *thread2;
+
+static DEFINE_MUTEX(mutex_a);
+static DEFINE_MUTEX(mutex_b);
+
+static int thread_func(void *data)
+{
+    char *name = (char *) data;
+
+    if (!strcmp(name, "Thread1")) {
+        printk(KERN_INFO "%s: Acquiring mutex A...\n", name);
+        mutex_lock(&mutex_a);
+        is_ready_thread1 = 1;
+        while (!is_ready_thread2);
+        printk(KERN_INFO "%s: Got mutex A. Now trying to acquire mutex B...\n", name);
+        mutex_lock(&mutex_b);  // This will block, causing deadlock
+        printk(KERN_INFO "%s: Got mutex B.\n", name);
+    } else {
+        printk(KERN_INFO "%s: Acquiring mutex B...\n", name);
+        mutex_lock(&mutex_b);
+        is_ready_thread2 = 1;
+        while (!is_ready_thread1);
+        printk(KERN_INFO "%s: Got mutex B. Now trying to acquire mutex A...\n", name);
+        mutex_lock(&mutex_a);  // This will block, causing deadlock
+        printk(KERN_INFO "%s: Got mutex A.\n", name);
+    }
+
+    return 0;
+}
+
+static int trigger_deadlock(void)
+{
+    thread1 = kthread_run(thread_func, (void *) "Thread1", "thread1");
+    if (IS_ERR(thread1)) {
+        printk(KERN_ERR "Failed to create thread1\n");
+        return PTR_ERR(thread1);
+    }
+
+    thread2 = kthread_run(thread_func, (void *) "Thread2", "thread2");
+    if (IS_ERR(thread2)) {
+        printk(KERN_ERR "Failed to create thread2\n");
+        kthread_stop(thread1);
+        return PTR_ERR(thread2);
+    }
+
+    return 0;
+}
+
 static int trigger_init(void) {
     if (test_type == 0)
         trigger_oom();
@@ -68,12 +120,18 @@ static int trigger_init(void) {
         trigger_oops();
     else if (test_type == 2)
         trigger_rcu();
+    else if (test_type == 3)
+        trigger_deadlock();
 
     return 0;           // 加载模块不应该有返回值，但这里返回0避免编译警告。
 }
 
 static void __exit trigger_exit(void) {
-    printk(KERN_INFO "oom_trigger: Exiting the oom_trigger LKM\n");
+    if (test_type == 3) {
+        kthread_stop(thread1);
+        kthread_stop(thread2);
+        printk(KERN_INFO "Deadlock trigger exit.\n");
+    }
 }
 
 module_init(trigger_init);