#include <linux/kprobes.h>

// for diag_kallsyms_lookup_name
extern unsigned long (*diag_kallsyms_lookup_name)(const char *name);
extern struct kprobe kprobe_kallsyms_lookup_name;

// int fn_kallsyms_lookup_name_init(void); // init kallsyms_lookup_name

// form
// https://github.com/alibaba/diagnose-tools/blob/8cd905a1c17f2201e460a2d607413a1303757a32/SOURCE/module/internal.h#L65
// look for current function address, all the function with prefix "orig_" are
#define LOOKUP_SYMS(name)                                                      \
  do {                                                                         \
    orig_##name = (void *)diag_kallsyms_lookup_name(#name);                    \
    if (!orig_##name) {                                                        \
      printk(KERN_ERR "kallsyms_lookup_name: %s\n", #name);                    \
      return -EINVAL;                                                          \
    }                                                                          \
  } while (0)

#define LOOKUP_SYMS_NORET(name)                                                \
  do {                                                                         \
    orig_##name = (void *)diag_kallsyms_lookup_name(#name);                    \
    if (!orig_##name)                                                          \
      pr_err("kallsyms_lookup_name: %s\n", #name);                             \
  } while (0)

int init_orig_fun(void);

// All the function with prefix "orig_X" are
// LOOKUP_SYMS(X);
extern unsigned int (*orig_stack_trace_save_tsk)(struct task_struct *task,
                                                 unsigned long *store,
                                                 unsigned int size,
                                                 unsigned int skipnr);
extern void (*orig_show_stack)(struct task_struct *task, unsigned long *sp,
                               const char *loglvl); // output kernel stack
extern struct sched_class *orig_idle_sched_class;   // idle process
extern int (*orig_get_task_type)(struct sched_entity *se);
extern int (*orig_kernfs_name)(struct kernfs_node *kn, char *buf,
                               size_t buflen); // get sysfs name
extern int (*orig_access_remote_vm)(
    struct mm_struct *mm, unsigned long addr, void *buf, int len,
    unsigned int gup_flags); // read remote memory
extern struct task_struct *(*orig_find_task_by_vpid)(
    pid_t nr); // find task by pid

extern void (*orig_open_softirq)(int nr, void (*action)(struct softirq_action *));
extern void (*orig_raise_softirq)(unsigned int nr);