#include <linux/kernfs.h>
#include <linux/sched.h>

#define CGROUP_NAME_LEN 32 // max length of cgroup name
#define TASK_COMM_LEN 16   // max length of task name

#define BACKTRACE_DEPTH2 30 // max depth of backtrace

#define PROCESS_CHAINS_COUNT 10 // max count of process chains
#define PROCESS_ARGV_LEN 128    // max length of process argv

// from
// https://github.com/alibaba/diagnose-tools/blob/8cd905a1c17f2201e460a2d607413a1303757a32/SOURCE/uapi/ali_diagnose.h

typedef struct {
  char cgroup_buf[CGROUP_NAME_LEN];
  char cgroup_cpuset[CGROUP_NAME_LEN];
  int pid;
  int tgid;
  int container_pid;
  int container_tgid;
  long state;
  int task_type;
  unsigned long syscallno;
  /**
   * 0->user 1->sys 2->idle
   */
  unsigned long sys_task;
  /**
   * 1->user mode 0->sys mode -1->unknown
   */
  unsigned long user_mode;
  char comm[TASK_COMM_LEN];
} task_detail;

typedef struct {
  unsigned long stack[BACKTRACE_DEPTH2];
} kern_stack_detail;

typedef struct {
  struct pt_regs regs;
  unsigned long ip;
  unsigned long bp;
  unsigned long sp;
  unsigned long stack[BACKTRACE_DEPTH2];
} user_stack_detail;

typedef struct {
  unsigned int full_argv[PROCESS_CHAINS_COUNT];        //
  char chains[PROCESS_CHAINS_COUNT][PROCESS_ARGV_LEN]; // process chains argv
  unsigned int tgid[PROCESS_CHAINS_COUNT];             // process chains tgid
} proc_chains_detail;

// most important struct
typedef struct {
  int et_type;
  unsigned long id;
  unsigned long long tv;
  task_detail task;               // brief
  user_stack_detail user_stack;   // user stack
  kern_stack_detail kern_stack;   // kernel stack
  proc_chains_detail proc_chains; // process chains argv
} variable_monitor_task;

typedef struct {
  struct radix_tree_root mm_tree;
  spinlock_t mm_tree_lock;
} mm_tree;

void diag_task_brief(struct task_struct *tsk,
                     task_detail *detail); // get task brief
void diag_task_user_stack(struct task_struct *tsk,
                          user_stack_detail *detail); // get task user stack
void diag_task_kern_stack(struct task_struct *tsk,
                          kern_stack_detail *detail); // get task kernel stack
void dump_proc_chains_argv(
    int style, struct task_struct *tsk, mm_tree *mm_tree,
    proc_chains_detail *detail); // get process chains argv

// orig_X
struct sched_class *orig_idle_sched_class;
int (*orig_get_task_type)(struct sched_entity *se);
int (*orig_kernfs_name)(struct kernfs_node *kn, char *buf, size_t buflen);
int (*orig_access_remote_vm)(struct mm_struct *mm, unsigned long addr,
                             void *buf, int len, unsigned int gup_flags);
extern unsigned int (*orig_stack_trace_save_tsk)(struct task_struct *task,
                                                 unsigned long *store,
                                                 unsigned int size,
                                                 unsigned int skipnr);