1

linux_kernel/msg.c

@@ -0,0 +1,69 @@
+#include "head.h"
+struct msg_list g_msg_list;
+spinlock_t g_msg_lock;
+size_t g_msg_length;
+void push_msg(struct kernel_msg_t *msg) {
+    if (get_msg_list_length() > 0x1000) {
+        printk(KERN_ERR "Too many messages in the list\n");
+        return;
+    }
+    struct msg_list *new_msg = kmalloc(sizeof(struct msg_list), GFP_KERNEL);
+    if (new_msg == NULL) {
+        printk(KERN_ERR "Failed to allocate memory for new msg\n");
+        return;
+    }
+    new_msg->msg = msg;
+    new_msg->msg->check_sum = MSG_CHECK_SUM;
+    spin_lock_bh(&g_msg_lock);
+    list_add_tail(&new_msg->node, &g_msg_list.node);
+    g_msg_length++;
+    spin_unlock_bh(&g_msg_lock);
+    if (g_is_r3_ready) {
+        wake_up_interruptible(&g_r3_wait_queue);
+    }
+}
+struct kernel_msg_t *get_msg(void) {
+    struct kernel_msg_t *msg = NULL;
+    struct msg_list *tmp = NULL;
+    spin_lock_bh(&g_msg_lock);
+    if (list_empty(&g_msg_list.node)) {
+        spin_unlock_bh(&g_msg_lock);
+        return NULL;
+    }
+    tmp = list_first_entry(&g_msg_list.node, struct msg_list, node);
+    list_del(&tmp->node);
+    g_msg_length--;
+    spin_unlock_bh(&g_msg_lock);
+    msg = tmp->msg;
+    kfree(tmp);
+    return msg;
+}
+size_t get_msg_list_length(void) {
+    size_t len = 0;
+    spin_lock_bh(&g_msg_lock);
+    len = g_msg_length;
+    spin_unlock_bh(&g_msg_lock);
+    return len;
+}
+void cleanup_msg(void) {
+    struct msg_list *tmp = NULL;
+    struct msg_list *next = NULL;
+    spin_lock_bh(&g_msg_lock);
+    list_for_each_entry_safe(tmp, next, &g_msg_list.node, node) {
+        list_del(&tmp->node);
+        kfree(tmp->msg);
+        kfree(tmp);
+    }
+    g_msg_length = 0;
+    spin_unlock_bh(&g_msg_lock);
+}
+void init_msg(void) {
+    INIT_LIST_HEAD(&(g_msg_list.node));
+    spin_lock_init(&g_msg_lock);
+    g_msg_length = 0;
+}
+EXPORT_SYMBOL(push_msg);
+EXPORT_SYMBOL(get_msg);
+EXPORT_SYMBOL(get_msg_list_length);
+EXPORT_SYMBOL(cleanup_msg);
+EXPORT_SYMBOL(init_msg);