derzeit keine Struktur von Modul zu Benutzerraum

Question

Das ist mein Modul auf Kernel-Ebene kopieren:

#include <linux/kernel.h> 
#include <linux/module.h> 
#include <linux/fs.h> 
#include <asm/uaccess.h> 
#include <linux/miscdevice.h> 


static struct miscdevice my_dev; 

struct time_check 
{ 
time_t tv_sec_ker; 
time_t tv_sec_nsday; 
long int tv_nsec_ker; 
long int tv_nsec_nsday; 
}time; 


ssize_t read_function(struct file *file_pointer, char *buffer, size_t count, loff_t *offset); 

int open_function(struct inode *node_pointer,struct file *file_pointer); 


static const struct file_operations file_op = { 
     .read = read_function, 
     .open = open_function, 
}; 

int open_function(struct inode *node_pointer,struct file *file_pointer) 
{ 
     printk(" opened the file module\n"); 
     return 0; 
} 

ssize_t read_function(struct file *file_pointer,char *buffer,size_t count,loff_t *offset) 
{ 


    int error_no=0; 
struct timespec gets_time; 
struct time_check time_s; 
if(access_ok(VERIFY_READ,buffer,2*sizeof(struct timespec))) 
{ 
struct timespec cur_time=current_kernel_time();   
printk("current_kernel_time:\n%lld %lld\n",(long long)(cur_time.tv_sec),(long long)(cur_time.tv_nsec)); 

getnstimeofday(&gets_time); 
      printk("getnstimeofday:\n%lld %lld\n",(long long)(gets_time.tv_sec),(long long)(gets_time.tv_nsec)); 


      time_s.tv_sec_ker=cur_time.tv_sec; 
      time_s.tv_nsec_ker=cur_time.tv_nsec; 
      time_s.tv_sec_nsday=gets_time.tv_sec; 
      time_s.tv_nsec_nsday=gets_time.tv_nsec; 

      printk("current_kernel_time_copied:\n%lld %lld\n",(long long)(time_s.tv_sec_ker),(long long)(time_s.tv_nsec_ker)); 
      printk("getnstimepfday_copied:\n%lld %lld\n",(long long)(time_s.tv_sec_nsday),(long long)(time_s.tv_nsec_nsday)); 

      if(copy_to_user(buffer,&time_s,sizeof(time_s))) 
        error_no=-EFAULT; 

    } 
    else 
    { 
    error_no=-EFAULT; 
    } 
    return error_no; 



} 
int init_function(void) 
{ 
    int retval; 
    my_dev.minor = MISC_DYNAMIC_MINOR; 
    my_dev.name = "mytime"; 
    my_dev.fops = &file_op; 
    retval = misc_register(&my_dev); 
    if (retval) return retval; 
    printk("got minor %i\n",my_dev.minor); 
    return 0; 
} 


void exit_function(void) 
{ 

     misc_deregister(&my_dev); 
} 

module_init(init_function); 
module_exit(exit_function); 

Das ist Funktion meiner Benutzerebene:

#include<stdio.h> 
#include<fcntl.h> 
#include<unistd.h> 
#include <sys/stat.h> 

struct time_check 
{ 
time_t tv_sec_ker; 
time_t tv_sec_nsday; 
long int tv_nsec_ker; 
long int tv_nsec_nsday; 
}ti; 

int main() 
{ 
     FILE *fd; 
     int count; 
     struct time_check time; 

     /* open device */ 
     fd = fopen("/dev/mytime","r"); 

     /* read from device */ 
     count =fread(&time,sizeof(time),1,fd); 
     printf("Return value %d\n", count); 
     printf("size of time:%ld\n",sizeof(time)); 
     printf("ker_sec:%ld\nker_nsec:%ld\nnsday_sec:%ld\nnsday_nsec:%ld\n",time.tv_sec_ker,time.tv_nsec_ker,time.tv_sec_nsday,time.tv_nsec_nsday); 

     /* close device */ 
     fclose(fd); 

     return 0; 
} 

Aber ich bin nicht in der Lage, die Struktur zu kopieren. Ich kann nicht verstehen, wo ich falsch gemacht habe. Es wird auf der Benutzerebene ein gewisser Müllwert gedruckt.

Rückgabewert 0

Größe der Zeit: 32

ker_sec: 0

ker_nsec: 4196144

nsday_sec: 0

nsday_nsec: 4195696

Kann jemand Sag mir, welche Veränderungen ich machen sollte, um erfolgreich zu sein Kopieren Sie die Struktur

Answer 1

Sie geben einen falschen Rückgabewert.

read_function sollte die genaue Zahl zurückgeben, die Sie in den Benutzerbereich kopiert haben.

Sie geben error_no zurück, also sollte die Kopie erfolgreich sein, sollte sie die Größe der Struktur "time_s" haben.

Der Ausgang:

Return value 1 
size of time:32 
ker_sec:1508833722 
ker_nsec:745536502 
nsday_sec:1508833722 
nsday_nsec:746151801 

Der Quellcode:

ssize_t read_function(struct file *file_pointer,char *buffer,size_t count,loff_t *offset) 
{ 
    int error_no=0; 
    struct timespec gets_time; 
    struct time_check time_s; 
    if(access_ok(VERIFY_READ,buffer,2*sizeof(struct timespec))) 
    { 
     struct timespec cur_time=current_kernel_time(); 
     printk("current_kernel_time:\n%lld %lld\n",(long long)(cur_time.tv_sec),(long long)(cur_time.tv_nsec)); 

     getnstimeofday(&gets_time); 
     printk("getnstimeofday:\n%lld %lld\n",(long long)(gets_time.tv_sec),(long long)(gets_time.tv_nsec)); 

     time_s.tv_sec_ker=cur_time.tv_sec; 
     time_s.tv_nsec_ker=cur_time.tv_nsec; 
     time_s.tv_sec_nsday=gets_time.tv_sec; 
     time_s.tv_nsec_nsday=gets_time.tv_nsec; 

     printk("current_kernel_time_copied:\n%lld %lld\n",(long long)(time_s.tv_sec_ker),(long long)(time_s.tv_nsec_ker)); 
     printk("getnstimepfday_copied:\n%lld %lld\n",(long long)(time_s.tv_sec_nsday),(long long)(time_s.tv_nsec_nsday)); 

     if(!copy_to_user(buffer,&time_s,sizeof(time_s))) 
     { 
       error_no = sizeof(time_s); 
     }  
     else 
     { 
       error_no=-EFAULT; 
     } 

    } 
    else 
    { 
     error_no=-EFAULT; 
    } 

    printk("=== copy number ====%d", error_no); 
    return error_no; 
}