Proof of work SO2, lab02

tools/labs/.gitignore

@@ -1,4 +1,4 @@
-/skels/
+#/skels/
 vmlinux
 zImage
 serial.pts

tools/labs/skels/Kbuild

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+# autogenerated, do not edit 
+ccflags-y += -Wno-unused-function -Wno-unused-label -Wno-unused-variable 
+obj-m += ./kernel_api/5-list-full/
+obj-m += ./kernel_api/4-list/
+obj-m += ./kernel_api/1-mem/
+obj-m += ./kernel_api/2-sched-spin/
+obj-m += ./kernel_api/7-list-test/
+obj-m += ./kernel_api/3-memory/
+obj-m += ./kernel_api/6-list-sync/

tools/labs/skels/kernel_api/1-mem/Kbuild

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+ccflags-y = -Wno-unused-function -Wno-unused-label -Wno-unused-variable
+
+obj-m = mem.o

tools/labs/skels/kernel_api/1-mem/mem.c

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+/*
+ * Kernel API lab
+ * 
+ * mem.c - Memory allocation in Linux
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/ctype.h>
+
+MODULE_DESCRIPTION("Print memory");
+MODULE_AUTHOR("SO2");
+MODULE_LICENSE("GPL");
+
+static char *mem;
+
+static int mem_init(void)
+{
+ size_t i;
+
+ mem = kmalloc(4096 * sizeof(*mem), GFP_KERNEL);
+ if (mem == NULL)
+ goto err_mem;
+
+ pr_info("chars: ");
+ for (i = 0; i < 4096; i++) {
+ if (isalpha(mem[i]))
+ printk("%c ", mem[i]);
+ }
+ pr_info("\n");
+
+ return 0;
+
+err_mem:
+ return -1;
+}
+
+static void mem_exit(void)
+{
+ kfree(mem);
+}
+
+module_init(mem_init);
+module_exit(mem_exit);

tools/labs/skels/kernel_api/2-sched-spin/Kbuild

@@ -0,0 +1,3 @@
+ccflags-y = -Wno-unused-function -Wno-unused-label -Wno-unused-variable
+
+obj-m = sched-spin.o

tools/labs/skels/kernel_api/2-sched-spin/sched-spin.c

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+/*
+ * Kernel API lab
+ *
+ * sched-spin.c: Sleeping in atomic context
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+
+MODULE_DESCRIPTION("Sleep while atomic");
+MODULE_AUTHOR("SO2");
+MODULE_LICENSE("GPL");
+
+static int sched_spin_init(void)
+{
+ spinlock_t lock;
+
+ spin_lock_init(&lock);
+
+ /* TODO 0: Use spin_lock to aquire the lock */
+ spin_lock(&lock);
+
+ set_current_state(TASK_INTERRUPTIBLE);
+ /* Try to sleep for 5 seconds. */
+ schedule_timeout(5 * HZ);
+
+ /* TODO 0: Use spin_unlock to release the lock */
+ spin_unlock(&lock);
+
+ return 0;
+}
+
+static void sched_spin_exit(void)
+{
+}
+
+module_init(sched_spin_init);
+module_exit(sched_spin_exit);

tools/labs/skels/kernel_api/3-memory/Kbuild

@@ -0,0 +1,3 @@
+ccflags-y = -Wno-unused-function -Wno-unused-label -Wno-unused-variable
+
+obj-m = memory.o

tools/labs/skels/kernel_api/3-memory/memory.c

@@ -0,0 +1,77 @@
+/*
+ * SO2 lab3 - task 3
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/sched/signal.h>
+
+MODULE_DESCRIPTION("Memory processing");
+MODULE_AUTHOR("SO2");
+MODULE_LICENSE("GPL");
+
+struct task_info {
+ pid_t pid;
+ unsigned long timestamp;
+};
+
+static struct task_info *ti1, *ti2, *ti3, *ti4;
+
+static struct task_info *task_info_alloc(int pid)
+{
+ struct task_info *ti;
+
+ /* TODO 1: allocated and initialize a task_info struct */
+ ti = kmalloc(sizeof(*ti), GFP_KERNEL);
+ if (ti == NULL)
+ return NULL;
+
+ ti->pid = pid;
+ ti->timestamp = jiffies;
+
+ return ti;
+}
+
+static int memory_init(void)
+{
+ struct task_struct *p;
+ p = get_current();
+
+ /* TODO 2: call task_info_alloc for current pid */
+ ti1 = task_info_alloc(p->pid);
+
+ /* TODO 2: call task_info_alloc for parent PID */
+ p = next_task(p);
+ ti2 = task_info_alloc(p->pid);
+
+ /* TODO 2: call task_info alloc for next process PID */
+ p = next_task(p);
+ ti3 = task_info_alloc(p->pid);
+
+ /* TODO 2: call task_info_alloc for next process of the next process */
+ p = next_task(p);
+ ti4 = task_info_alloc(p->pid);
+
+ return 0;
+}
+
+static void memory_exit(void)
+{
+ /* TODO 3: print ti* field values */
+ printk("pid: %d, timestamp: %ld\n", ti1->pid, ti1->timestamp);
+ printk("pid: %d, timestamp: %ld\n", ti2->pid, ti2->timestamp);
+ printk("pid: %d, timestamp: %ld\n", ti3->pid, ti3->timestamp);
+ printk("pid: %d, timestamp: %ld\n", ti4->pid, ti4->timestamp);
+
+ /* TODO 4: free ti* structures */
+ kfree(ti1);
+ kfree(ti2);
+ kfree(ti3);
+ kfree(ti4);
+}
+
+module_init(memory_init);
+module_exit(memory_exit);

tools/labs/skels/kernel_api/4-list/Kbuild

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+ccflags-y = -Wno-unused-function -Wno-unused-label -Wno-unused-variable
+
+obj-m = list.o

tools/labs/skels/kernel_api/4-list/list.c

@@ -0,0 +1,101 @@
+/*
+ * Kernel API lab
+ *
+ * list.c: Working with lists
+ * 
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/sched/signal.h>
+
+MODULE_DESCRIPTION("Use list to process task info");
+MODULE_AUTHOR("SO2");
+MODULE_LICENSE("GPL");
+
+struct task_info {
+ pid_t pid;
+ unsigned long timestamp;
+ struct list_head list;
+};
+
+static struct list_head head;
+
+static struct task_info *task_info_alloc(int pid)
+{
+ struct task_info *ti;
+
+ ti = kmalloc(sizeof(*ti), GFP_KERNEL);
+ if (ti == NULL)
+ return NULL;
+ ti->pid = pid;
+ ti->timestamp = jiffies;
+
+ return ti;
+}
+
+static void task_info_add_to_list(int pid)
+{
+ struct task_info *ti;
+
+ /* TODO 1: Allocate task_info and add it to list */
+ ti = task_info_alloc(pid);
+ list_add(&ti->list, &head);
+}
+
+static void task_info_add_for_current(void)
+{
+ /* Add current, parent, next and next of next to the list */
+ task_info_add_to_list(current->pid);
+ task_info_add_to_list(current->parent->pid);
+ task_info_add_to_list(next_task(current)->pid);
+ task_info_add_to_list(next_task(next_task(current))->pid);
+}
+
+static void task_info_print_list(const char *msg)
+{
+ struct list_head *p;
+ struct task_info *ti;
+
+ pr_info("%s: [ ", msg);
+ list_for_each(p, &head) {
+ ti = list_entry(p, struct task_info, list);
+ pr_info("(%d, %lu) ", ti->pid, ti->timestamp);
+ }
+ pr_info("]\n");
+}
+
+static void task_info_purge_list(void)
+{
+ struct list_head *p, *q;
+ struct task_info *ti;
+
+ /* TODO 2: Iterate over the list and delete all elements */
+ list_for_each_safe(p, q, &head)
+ {
+ ti = list_entry(p, struct task_info, list);
+ list_del(p);
+ kfree(ti);
+ }
+}
+
+static int list_init(void)
+{
+ INIT_LIST_HEAD(&head);
+
+ task_info_add_for_current();
+
+ return 0;
+}
+
+static void list_exit(void)
+{
+ task_info_print_list("before exiting");
+ task_info_purge_list();
+}
+
+module_init(list_init);
+module_exit(list_exit);

tools/labs/skels/kernel_api/5-list-full/Kbuild

@@ -0,0 +1,3 @@
+ccflags-y = -Wno-unused-function -Wno-unused-label -Wno-unused-variable
+
+obj-m = list-full.o