linked_list

tasks/linked_lists/module.c

@@ -34,9 +34,49 @@ static void __init test_stack(void)
     assert(stack_empty(&data_stack));
 }
 
-static void __init print_processes_backwards(void)
+static int __init print_processes_backwards(void)
 {
-    // TODO
+    LIST_HEAD(stack_of_process);
+    stack_entry_t* entry_ps = NULL;
+    struct task_struct* task_ps;
+    char* str = NULL;
+    for_each_process(task_ps)
+    {
+        str = (char*)kmalloc(TASK_COMM_LEN, GFP_KERNEL);
+        if (!str)
+        {
+            goto error;
+        }
+
+        entry_ps = create_stack_entry(str);
+        if (!entry_ps)
+        {
+            goto error;
+        }
+
+        get_task_comm(str, task_ps);
+        stack_push(&stack_of_process, entry_ps);
+    }
+
+    while(!stack_empty(&stack_of_process))
+    {
+        entry_ps = stack_pop(&stack_of_process);
+        str = STACK_ENTRY_DATA(entry_ps, char*);
+        printk(KERN_ALERT "%s\n", str);
+        delete_stack_entry(entry_ps);
+    }
+    return -ENOMEM;
+
+error:
+    printk(KERN_ALERT "error");
+    while(!stack_empty(&stack_of_process))
+    {
+        entry_ps = stack_pop(&stack_of_process);
+        str = STACK_ENTRY_DATA(entry_ps, char*);
+
+        delete_stack_entry(entry_ps);
+    }
+    return -ENOMEM;
 }
 
 static int __init ll_init(void)

tasks/linked_lists/stack.c

@@ -1,28 +1,30 @@
+#include <linux/slab.h>
+#include <linux/gfp.h>
 #include "stack.h"
 
 stack_entry_t* create_stack_entry(void *data)
 {
-    // TODO
-    (void)data;
-    return NULL;
+    stack_entry_t* entry_ptr = kmalloc(sizeof(stack_entry_t), GFP_KERNEL);
+    if (entry_ptr != NULL)
+    {
+        entry_ptr->data = data;
+        INIT_LIST_HEAD(&(entry_ptr->lh));
+    }
+    return entry_ptr;
 }
 
 void delete_stack_entry(stack_entry_t *entry)
 {
-    // TODO
-    (void)entry;
+    list_del(&entry->lh);
+    kfree(entry);
 }
 
 void stack_push(struct list_head *stack, stack_entry_t *entry)
 {
-    // TODO
-    (void)stack;
-    (void)entry;
+    list_add(&entry->lh, stack);
 }
 
 stack_entry_t* stack_pop(struct list_head *stack)
 {
-    // TODO
-    (void)stack;
-    return NULL;
+    return list_entry(stack->next, stack_entry_t, lh);
 }