kernel_watch_timer add *task

source/module/monitor_timer.c

@@ -1,18 +1,26 @@
 #include "monitor_timer.h"
+#include <linux/sched.h>
+#include <linux/pid.h>
 
 // Global variable
 kernel_watch_timer kernel_wtimer_list[MAX_TIMER_NUM] = {
-    0};                    // all kernel_watch_timer
+    0};                             // all kernel_watch_timer
 volatile int kernel_wtimer_num = 0; // current kernel_watch_timer number
 
 EXPORT_SYMBOL(kernel_wtimer_list); // export kernel_watch_timer_list
 EXPORT_SYMBOL(kernel_wtimer_num);  // export kernel_watch_timer_num
 
-
 #define TIMER_FILLED(timer) ((timer)->sentinel >= TIMER_MAX_WATCH_NUM)
-#define TIMER_EMPTY(timer) (!((timer)->time_ns | (timer)->sentinel))
+#define TIMER_EMPTY(timer)                                                     \
+  (!((timer)->time_ns | (timer)->sentinel | ((timer)->task != NULL)))
 #define TIMER_NO_KWARG(timer) ((timer)->sentinel == 0)
 
+/**
+ * @brief search all kwarg, if pid match, delete all
+ *
+ * @param pid
+ * @return unsigned char
+ */
 unsigned char del_all_kwarg_by_pid(pid_t pid) {
   int i = 0;
   kernel_watch_timer *timer = NULL;
@@ -42,7 +50,6 @@ unsigned char del_all_kwarg_by_pid(pid_t pid) {
       }
       kernel_wtimer_num--;
       i--;
-
     }
   }
   return 0;
@@ -51,9 +58,23 @@ unsigned char del_all_kwarg_by_pid(pid_t pid) {
 /// @brief get a valuable timer
 /// @param time_ns
 /// @return kernel_watch_timer *, NULL means fail
-kernel_watch_timer *get_timer(unsigned long long time_ns) {
-  int i = 0;
+kernel_watch_timer *get_timer(pid_t tid, unsigned long long time_ns) {
   kernel_watch_timer *timer = NULL;
+  struct task_struct *task = NULL;
+  // if tid is 0 or current pid, task is current
+  if ((tid == 0) || (tid == current->pid)) {
+    task = current;
+  } else {
+    rcu_read_lock();
+    task = pid_task(find_vpid(tid), PIDTYPE_PID); // find task by pid
+    rcu_read_unlock();
+  }
+
+  if (task == NULL) {
+    pr_info("get_timer tid is abnormal\n");
+    return NULL;
+  }
+  int i = 0;
   // chose a timer
   for (i = 0; i < kernel_wtimer_num; i++) {
     timer = &kernel_wtimer_list[i];
@@ -61,7 +82,9 @@ kernel_watch_timer *get_timer(unsigned long long time_ns) {
     if (TIMER_EMPTY(timer)) {
       break;
     }
-    if ((timer->time_ns == time_ns) && (!TIMER_FILLED(timer))) {
+    // if task match, time_ns match, and timer is not filled
+    if ((task->pid == timer->task->pid) && (timer->time_ns == time_ns) &&
+        (!TIMER_FILLED(timer))) {
       break;
     }
   }
@@ -72,7 +95,8 @@ kernel_watch_timer *get_timer(unsigned long long time_ns) {
   // if a new timer, init it
   if (i > kernel_wtimer_num - 1) {
     printk(KERN_INFO "New timer\n");
-
+    // init timer
+    kernel_wtimer_list[i].task = task;
     kernel_wtimer_list[i].time_ns = time_ns;
     kernel_wtimer_list[i].sentinel = 0;
 
@@ -106,6 +130,13 @@ unsigned char timer_add_watch(kernel_watch_timer *timer,
   return 0;
 }
 
+/**
+ * @brief for each timer's k_watch_args, if pid match, delete it
+ *
+ * @param timer
+ * @param pid
+ * @return unsigned char
+ */
 unsigned char timer_del_watch_by_pid(kernel_watch_timer *timer, pid_t pid) {
   int i = 0;
   for (i = 0; i < timer->sentinel; i++) {
@@ -149,10 +180,11 @@ void start_all_hrTimer(void) {
     timer = &(kernel_wtimer_list[i]);
     TIMER_START(timer);
   }
-  printk(KERN_INFO "HrTimer start,module keep %d hrtimer for now\n", kernel_wtimer_num);
+  printk(KERN_INFO "HrTimer start,module keep %d hrtimer for now\n",
+         kernel_wtimer_num);
 }
 
-/// @brief cancel hrTimer and stop all work
+/// @brief cancel hrTimer
 /// @param
 void cancel_all_hrTimer(void) {
   int i = 0;
@@ -161,12 +193,13 @@ void cancel_all_hrTimer(void) {
     timer = &(kernel_wtimer_list[i]);
     TIMER_CANCEL(timer);
   }
-  printk(KERN_INFO "HrTimer cancel,module keep %d hrtimer for now\n", kernel_wtimer_num);
+  printk(KERN_INFO "HrTimer cancel,module keep %d hrtimer for now\n",
+         kernel_wtimer_num);
 }
 
 /**
  * @brief cancel all work
- * 
+ *
  */
 void cancel_all_work(void) {
   int i = 0;
@@ -179,7 +212,7 @@ void cancel_all_work(void) {
 
 /**
  * @brief destory all work
- * 
+ *
  */
 void cancel_destory_all_work(void) {
   int i = 0;

source/module/monitor_timer.h

@@ -32,6 +32,8 @@ typedef struct {
   unsigned long long time_ns; // hrTimer time interval (ns)
   struct hrtimer hr_timer;    // hrTimer
   ktime_t kt;                 // hrTimer time
+  struct task_struct *task;   // task pointer
+                              // one timer one task(process)
   unsigned sentinel;          // sentinel
   kernel_watch_arg
       k_watch_args[TIMER_MAX_WATCH_NUM];     // all watched kernel_watch_arg
@@ -40,8 +42,6 @@ typedef struct {
   int threshold_buffer[TIMER_MAX_WATCH_NUM]; //
   struct work_struct wk;                     // for handle
   unsigned long long tv;                     // time
-  struct task_struct *task;                  // task pointer
-                                             // one timer one task(process)
 } kernel_watch_timer;
 
 // Global variable
@@ -59,7 +59,7 @@ unsigned char del_all_kwarg_by_pid(pid_t pid);
 #define TIMER_CANCEL(timer) (hrtimer_cancel(&timer->hr_timer))
 
 // for timer
-kernel_watch_timer *get_timer(unsigned long long time_ns);
+kernel_watch_timer *get_timer(pid_t tid, unsigned long long time_ns);
 unsigned char timer_add_watch(kernel_watch_timer *timer,
                               kernel_watch_arg k_watch_arg);
 unsigned char timer_del_watch_by_pid(kernel_watch_timer *timer, pid_t pid);