在crash中可以用whatis命令查看数据类型信息以及函数的原型。

如果想知道某个数据是什么类型那么可以用下面的方法：

查看结构体的定义

crash> whatis mm_struct
struct mm_struct {
    struct {
        struct maple_tree mm_mt;
        unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned lon;
        unsigned long mmap_base;
        unsigned long mmap_legacy_base;
...

上面显示mm_struct是一个结构体，那么也可以用struct命令：

crash> struct mm_struct
struct mm_struct {
    struct {
        struct maple_tree mm_mt;
        unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned lon;
        unsigned long mmap_base;
        unsigned long mmap_legacy_base;
...

查看联合体的定义

crash> whatis snd_pcm_sync_id
union snd_pcm_sync_id {
    unsigned char id[16];
    unsigned short id16[8];
    unsigned int id32[4];
}
SIZE: 16

查看typedef类型

crash> whatis call_single_data_t
typedef struct __call_single_data {
    struct __call_single_node node;
    smp_call_func_t func;
    void *info;
} call_single_data_t;
SIZE: 32

crash> whatis cpumask_var_t
typedef struct cpumask {
    unsigned long bits[1];
} [1] cpumask_var_t;
SIZE: 8

crash> whatis smp_call_func_t
typedef void (*)(void *) smp_call_func_t;
SIZE: 8

查看枚举类型的定义

crash> whatis acpi_execute_type
typedef enum {
  OSL_GLOBAL_LOCK_HANDLER = 0
  OSL_NOTIFY_HANDLER = 1
  OSL_GPE_HANDLER = 2
  OSL_DEBUGGER_MAIN_THREAD = 3
  OSL_DEBUGGER_EXEC_THREAD = 4
  OSL_EC_POLL_HANDLER = 5
  OSL_EC_BURST_HANDLER = 6
} acpi_execute_type;

crash> whatis pageflags

enum pageflags {
  PG_locked = 0
  PG_referenced = 1
  PG_uptodate = 2
  PG_dirty = 3
  PG_lru = 4
  PG_active = 5
  PG_workingset = 6
  PG_waiters = 7
  PG_error = 8
  PG_slab = 9
  PG_owner_priv_1 = 10
  PG_arch_1 = 11
  ...
};

查看函数原型

crash> whatis blk_update_request
bool blk_update_request(struct request *, blk_status_t, unsigned int);

查看全局变量的类型

crash> whatis cfd_data
struct call_function_data cfd_data;