Hi all,
I am getting oops when i run a user land program to access data from simple
kernel land driver.
Can someone tell me where am i wrong???And how to correct it???
TIA
shan
P.S:i have enclose both userland appl. and kernal progrm. along with the oops
message.
<4>major number is 254
Inside test_open
Minor number is 0
Unable to handle kernel NULL pointer dereference at virtual address 00000029
printing eip:
c01372a0
*pde = 00000000
Oops: 0002
CPU: 0
EIP: 0010:[<c01372a0>] Tainted: P
EFLAGS: 00010202
EIP is at fget [kernel] 0x20
eax: c41d0000 ebx: c44ee000 ecx: 00000003 edx: 00000015
esi: fffffff7 edi: bffff9a4 ebp: 0000000d esp: c44eff8c
ds: 0018 es: 0018 ss: 0018
Process a.out (pid: 2880, stackpage=c44ef000)
Stack: c01365e9 c44effbc c60f0000 c768e260 c773f980 c44ee000 00000000 c7678000
c0302640 c44ee000 40016b4c bffff9a4 bffff938 c0106f3b 00000003 bffff920
0000000d 40016b4c bffff9a4 bffff938 00000003 0000002b 0000002b 00000003
Call Trace: [<c01365e9>] sys_read [kernel] 0x19
[<c0106f3b>] system_call [kernel] 0x33
Code: ff 42 14 89 d0 c3 8d 76 00 8d bc 27 00 00 00 00 8b 4c 24 04
<1>Unable to handle kernel NULL pointer dereference at virtual address 00000029
printing eip:
c01361e6
*pde = 00000000
Oops: 0000
CPU: 0
EIP: 0010:[<c01361e6>] Tainted: P
EFLAGS: 00010202
EIP is at filp_close [kernel] 0x6
eax: c41d0000 ebx: 00000015 ecx: 00000000 edx: 00000015
esi: c384f7a0 edi: 00000001 ebp: 00000003 esp: c44efe38
ds: 0018 es: 0018 ss: 0018
Process a.out (pid: 2880, stackpage=c44ef000)
Stack: 00000001 c384f7a0 c0119e5c 00000015 c384f7a0 00000000 c44ee000 0000000b
c44eff58 c011a461 c384f7a0 c022d63e c44eff58 c011439e c0230ec0 00000002
c0107497 00000000 c023166d c022c0f2 c022d63e 00000002 00000001 00000000
Call Trace: [<c0119e5c>] put_files_struct [kernel] 0x4c
[<c011a461>] do_exit [kernel] 0xd1
[<c022d63e>] .rodata.str1.1 [kernel] 0x1b39
[<c011439e>] bust_spinlocks [kernel] 0x3e
[<c0230ec0>] .rodata.str1.1 [kernel] 0x53bb
[<c0107497>] die [kernel] 0x47
[<c023166d>] .rodata.str1.1 [kernel] 0x5b68
[<c022c0f2>] .rodata.str1.1 [kernel] 0x5ed
[<c022d63e>] .rodata.str1.1 [kernel] 0x1b39
[<c01372a0>] fget [kernel] 0x20
[<c0114480>] do_page_fault [kernel] 0x0
[<c01147f7>] do_page_fault [kernel] 0x377
[<c0177266>] vt_console_print [kernel] 0x2a6
[<c01179b6>] __call_console_drivers [kernel] 0x46
[<c0117b2b>] call_console_drivers [kernel] 0xeb
[<c0117cb0>] printk [kernel] 0x100
[<c01476ec>] dput [kernel] 0x1c
[<c80c71da>] test_read [number] 0x136
[<c0114480>] do_page_fault [kernel] 0x0
[<c0107038>] error_code [kernel] 0x38
[<c01372a0>] fget [kernel] 0x20
[<c01365e9>] sys_read [kernel] 0x19
[<c0106f3b>] system_call [kernel] 0x33
Code: 8b 43 14 85 c0 75 13 68 60 82 21 c0 e8 b9 19 fe ff 59 31 c0
<4>Inside test_open
Minor number is 0
Unable to handle kernel NULL pointer dereference at virtual address 00000029
printing eip:
c01372a0
*pde = 00000000
Oops: 0002
CPU: 0
EIP: 0010:[<c01372a0>] Tainted: P
EFLAGS: 00010202
EIP is at fget [kernel] 0x20
eax: c41d0800 ebx: c44ee000 ecx: 00000003 edx: 00000015
esi: fffffff7 edi: bffff3a4 ebp: 00000001 esp: c44eff8c
ds: 0018 es: 0018 ss: 0018
Process a.out (pid: 2892, stackpage=c44ef000)
Stack: c01365e9 c44effbc c60f0000 c768e260 c773f980 c44ee000 00000000 c7678000
c0302640 c44ee000 40016b4c bffff3a4 bffff338 c0106f3b 00000003 bffff320
00000001 40016b4c bffff3a4 bffff338 00000003 0000002b 0000002b 00000003
Call Trace: [<c01365e9>] sys_read [kernel] 0x19
[<c0106f3b>] system_call [kernel] 0x33
Code: ff 42 14 89 d0 c3 8d 76 00 8d bc 27 00 00 00 00 8b 4c 24 04
<1>Unable to handle kernel NULL pointer dereference at virtual address 00000029
printing eip:
c01361e6
*pde = 00000000
Oops: 0000
CPU: 0
EIP: 0010:[<c01361e6>] Tainted: P
EFLAGS: 00010202
EIP is at filp_close [kernel] 0x6
eax: c41d0800 ebx: 00000015 ecx: 00000000 edx: 00000015
esi: c384fc80 edi: 00000001 ebp: 00000003 esp: c44efe38
ds: 0018 es: 0018 ss: 0018
Process a.out (pid: 2892, stackpage=c44ef000)
Stack: 00000001 c384fc80 c0119e5c 00000015 c384fc80 00000000 c44ee000 0000000b
c44eff58 c011a461 c384fc80 c022d63e c44eff58 c011439e c0230ec0 00000002
c0107497 00000000 c023166d c022c0f2 c022d63e 00000002 00000001 00000000
Call Trace: [<c0119e5c>] put_files_struct [kernel] 0x4c
[<c011a461>] do_exit [kernel] 0xd1
[<c022d63e>] .rodata.str1.1 [kernel] 0x1b39
[<c011439e>] bust_spinlocks [kernel] 0x3e
[<c0230ec0>] .rodata.str1.1 [kernel] 0x53bb
[<c0107497>] die [kernel] 0x47
[<c023166d>] .rodata.str1.1 [kernel] 0x5b68
[<c022c0f2>] .rodata.str1.1 [kernel] 0x5ed
[<c022d63e>] .rodata.str1.1 [kernel] 0x1b39
[<c01372a0>] fget [kernel] 0x20
[<c0114480>] do_page_fault [kernel] 0x0
[<c01147f7>] do_page_fault [kernel] 0x377
[<c0177266>] vt_console_print [kernel] 0x2a6
[<c01179b6>] __call_console_drivers [kernel] 0x46
[<c0117b2b>] call_console_drivers [kernel] 0xeb
[<c0117cb0>] printk [kernel] 0x100
[<c01476ec>] dput [kernel] 0x1c
[<c80c71da>] test_read [number] 0x136
[<c0114480>] do_page_fault [kernel] 0x0
[<c0107038>] error_code [kernel] 0x38
[<c01372a0>] fget [kernel] 0x20
[<c01365e9>] sys_read [kernel] 0x19
[<c0106f3b>] system_call [kernel] 0x33
Code: 8b 43 14 85 c0 75 13 68 60 82 21 c0 e8 b9 19 fe ff 59 31 c0
<1>Module dying<4>major number is 254
Inside test_open
Minor number is 0
Unable to handle kernel NULL pointer dereference at virtual address 00000029
printing eip:
c01372a0
*pde = 00000000
Oops: 0002
CPU: 0
EIP: 0010:[<c01372a0>] Tainted: P
EFLAGS: 00010202
EIP is at fget [kernel] 0x20
eax: c41d0c00 ebx: c44ee000 ecx: 00000003 edx: 00000015
esi: fffffff7 edi: bffff1a4 ebp: 00000001 esp: c44eff8c
ds: 0018 es: 0018 ss: 0018
Process a.out (pid: 2896, stackpage=c44ef000)
Stack: c01365e9 c44effbc c60f0000 c768e260 c773f980 c44ee000 00000000 c7678000
c0302640 c44ee000 40016b4c bffff1a4 bffff138 c0106f3b 00000003 bffff120
00000001 40016b4c bffff1a4 bffff138 00000003 0000002b 0000002b 00000003
Call Trace: [<c01365e9>] sys_read [kernel] 0x19
[<c0106f3b>] system_call [kernel] 0x33
Code: ff 42 14 89 d0 c3 8d 76 00 8d bc 27 00 00 00 00 8b 4c 24 04
<1>Unable to handle kernel NULL pointer dereference at virtual address 00000029
printing eip:
c01361e6
*pde = 00000000
Oops: 0000
CPU: 0
EIP: 0010:[<c01361e6>] Tainted: P
EFLAGS: 00010202
EIP is at filp_close [kernel] 0x6
eax: c41d0c00 ebx: 00000015 ecx: 00000000 edx: 00000015
esi: c384fe20 edi: 00000001 ebp: 00000003 esp: c44efe38
ds: 0018 es: 0018 ss: 0018
Process a.out (pid: 2896, stackpage=c44ef000)
Stack: 00000001 c384fe20 c0119e5c 00000015 c384fe20 00000000 c44ee000 0000000b
c44eff58 c011a461 c384fe20 00000004 00000000 c022d63e c44eff58 c44eff58
c0230ec0 00000018 c0230018 ffffff00 c01074a3 00000010 00000292 00000000
Call Trace: [<c0119e5c>] put_files_struct [kernel] 0x4c
[<c011a461>] do_exit [kernel] 0xd1
[<c022d63e>] .rodata.str1.1 [kernel] 0x1b39
[<c0230ec0>] .rodata.str1.1 [kernel] 0x53bb
[<c0230018>] .rodata.str1.1 [kernel] 0x4513
[<c01074a3>] die [kernel] 0x53
[<c01372a0>] fget [kernel] 0x20
[<c0114480>] do_page_fault [kernel] 0x0
[<c01147f7>] do_page_fault [kernel] 0x377
[<c0177266>] vt_console_print [kernel] 0x2a6
[<c01179b6>] __call_console_drivers [kernel] 0x46
[<c0117b2b>] call_console_drivers [kernel] 0xeb
[<c0117cb0>] printk [kernel] 0x100
[<c01476ec>] dput [kernel] 0x1c
[<c80c71da>] test_read [number] 0x136
[<c0114480>] do_page_fault [kernel] 0x0
[<c0107038>] error_code [kernel] 0x38
[<c01372a0>] fget [kernel] 0x20
[<c01365e9>] sys_read [kernel] 0x19
[<c0106f3b>] system_call [kernel] 0x33
Code: 8b 43 14 85 c0 75 13 68 60 82 21 c0 e8 b9 19 fe ff 59 31 c0
<4>Inside test_open
Minor number is 0
Unable to handle kernel NULL pointer dereference at virtual address 00000029
printing eip:
c01372a0
*pde = 00000000
Oops: 0002
CPU: 0
EIP: 0010:[<c01372a0>] Tainted: P
EFLAGS: 00010202
EIP is at fget [kernel] 0x20
eax: c462d400 ebx: c44ee000 ecx: 00000003 edx: 00000015
esi: fffffff7 edi: bfffec24 ebp: 00000001 esp: c44eff8c
ds: 0018 es: 0018 ss: 0018
Process a.out (pid: 2907, stackpage=c44ef000)
Stack: c01365e9 c44effbc c60f0000 c768e260 c773f980 c44ee000 00000000 c7678000
c0302640 c44ee000 40016b4c bfffec24 bfffebb8 c0106f3b 00000003 bfffebb4
00000001 40016b4c bfffec24 bfffebb8 00000003 0000002b 0000002b 00000003
Call Trace: [<c01365e9>] sys_read [kernel] 0x19
[<c0106f3b>] system_call [kernel] 0x33
Code: ff 42 14 89 d0 c3 8d 76 00 8d bc 27 00 00 00 00 8b 4c 24 04
<1>Unable to handle kernel NULL pointer dereference at virtual address 00000029
printing eip:
c01361e6
*pde = 00000000
Oops: 0000
CPU: 0
EIP: 0010:[<c01361e6>] Tainted: P
EFLAGS: 00010202
EIP is at filp_close [kernel] 0x6
eax: c462d400 ebx: 00000015 ecx: 00000000 edx: 00000015
esi: c384f2c0 edi: 00000001 ebp: 00000003 esp: c44efe38
ds: 0018 es: 0018 ss: 0018
Process a.out (pid: 2907, stackpage=c44ef000)
Stack: 00000001 c384f2c0 c0119e5c 00000015 c384f2c0 00000000 c44ee000 0000000b
c44eff58 c011a461 c384f2c0 c022d63e c44eff58 c011439e c0230ec0 00000002
c0107497 00000000 c023166d c022c0f2 c022d63e 00000002 00000001 00000000
Call Trace: [<c0119e5c>] put_files_struct [kernel] 0x4c
[<c011a461>] do_exit [kernel] 0xd1
[<c022d63e>] .rodata.str1.1 [kernel] 0x1b39
[<c011439e>] bust_spinlocks [kernel] 0x3e
[<c0230ec0>] .rodata.str1.1 [kernel] 0x53bb
[<c0107497>] die [kernel] 0x47
[<c023166d>] .rodata.str1.1 [kernel] 0x5b68
[<c022c0f2>] .rodata.str1.1 [kernel] 0x5ed
[<c022d63e>] .rodata.str1.1 [kernel] 0x1b39
[<c01372a0>] fget [kernel] 0x20
[<c0114480>] do_page_fault [kernel] 0x0
[<c01147f7>] do_page_fault [kernel] 0x377
[<c0177266>] vt_console_print [kernel] 0x2a6
[<c01179b6>] __call_console_drivers [kernel] 0x46
[<c0117b2b>] call_console_drivers [kernel] 0xeb
[<c0117cb0>] printk [kernel] 0x100
[<c01476ec>] dput [kernel] 0x1c
[<c80c71da>] test_read [number] 0x136
[<c0114480>] do_page_fault [kernel] 0x0
[<c0107038>] error_code [kernel] 0x38
[<c01372a0>] fget [kernel] 0x20
[<c01365e9>] sys_read [kernel] 0x19
[<c0106f3b>] system_call [kernel] 0x33
Code: 8b 43 14 85 c0 75 13 68 60 82 21 c0 e8 b9 19 fe ff 59 31 c0
<4>Inside test_open
Minor number is 0
Unable to handle kernel NULL pointer dereference at virtual address 00000029
printing eip:
c01372a0
*pde = 00000000
Oops: 0002
CPU: 0
EIP: 0010:[<c01372a0>] Tainted: P
EFLAGS: 00010202
EIP is at fget [kernel] 0x20
eax: c462d000 ebx: c44ee000 ecx: 00000003 edx: 00000015
esi: fffffff7 edi: bffff224 ebp: 00000001 esp: c44eff8c
ds: 0018 es: 0018 ss: 0018
Process a.out (pid: 2959, stackpage=c44ef000)
Stack: c01365e9 c44effbc c60f0000 c768e260 c773f980 c44ee000 00000000 c7678000
c0302640 c44ee000 40016b4c bffff224 bffff1b8 c0106f3b 00000003 bffff1b4
00000001 40016b4c bffff224 bffff1b8 00000003 0000002b 0000002b 00000003
Call Trace: [<c01365e9>] sys_read [kernel] 0x19
[<c0106f3b>] system_call [kernel] 0x33
Code: ff 42 14 89 d0 c3 8d 76 00 8d bc 27 00 00 00 00 8b 4c 24 04
<1>Unable to handle kernel NULL pointer dereference at virtual address 00000029
printing eip:
c01361e6
*pde = 00000000
Oops: 0000
CPU: 0
EIP: 0010:[<c01361e6>] Tainted: P
EFLAGS: 00010202
EIP is at filp_close [kernel] 0x6
eax: c462d000 ebx: 00000015 ecx: 00000000 edx: 00000015
esi: c384f600 edi: 00000001 ebp: 00000003 esp: c44efe38
ds: 0018 es: 0018 ss: 0018
Process a.out (pid: 2959, stackpage=c44ef000)
Stack: 00000001 c384f600 c0119e5c 00000015 c384f600 00000000 c44ee000 0000000b
c44eff58 c011a461 c384f600 c022d63e c44eff58 c011439e c0230ec0 00000002
c0107497 00000000 c023166d c022c0f2 c022d63e 00000002 00000001 00000000
Call Trace: [<c0119e5c>] put_files_struct [kernel] 0x4c
[<c011a461>] do_exit [kernel] 0xd1
[<c022d63e>] .rodata.str1.1 [kernel] 0x1b39
[<c011439e>] bust_spinlocks [kernel] 0x3e
[<c0230ec0>] .rodata.str1.1 [kernel] 0x53bb
[<c0107497>] die [kernel] 0x47
[<c023166d>] .rodata.str1.1 [kernel] 0x5b68
[<c022c0f2>] .rodata.str1.1 [kernel] 0x5ed
[<c022d63e>] .rodata.str1.1 [kernel] 0x1b39
[<c01372a0>] fget [kernel] 0x20
[<c0114480>] do_page_fault [kernel] 0x0
[<c01147f7>] do_page_fault [kernel] 0x377
[<c0177266>] vt_console_print [kernel] 0x2a6
[<c01179b6>] __call_console_drivers [kernel] 0x46
[<c0117b2b>] call_console_drivers [kernel] 0xeb
[<c0117cb0>] printk [kernel] 0x100
[<c01476ec>] dput [kernel] 0x1c
[<c80c71da>] test_read [number] 0x136
[<c0114480>] do_page_fault [kernel] 0x0
[<c0107038>] error_code [kernel] 0x38
[<c01372a0>] fget [kernel] 0x20
[<c01365e9>] sys_read [kernel] 0x19
[<c0106f3b>] system_call [kernel] 0x33
Code: 8b 43 14 85 c0 75 13 68 60 82 21 c0 e8 b9 19 fe ff 59 31 c0
#include<stdio.h>
#include<fcntl.h>
#include<unistd.h>
#define BUFFSIZE 14
int main()
{
char buf[BUFFSIZE];
int recv;
int fd=open("/dev/Test",O_RDONLY);
if(fd < 0){
perror("open");
return -1;
}
recv=read(fd,buf,BUFFSIZE);
if(recv < 0){
perror("recv");
return -1;
}
printf("%s\n",buf);
printf("Byte recvd is %d\n",recv);
close(fd);
printf("Ending user prgm...\n");
return 0;
}
#define MODULE
#include<linux/kernel.h>
#include<linux/module.h>
#include<linux/fs.h>
#include<asm/uaccess.h>
int test_major=0,major;
char *data="copy_to_user";
/*MODULE_PARM(val,"i");*/
/*typedef struct test_device {
void **data;
unsigned long size;
struct semaphore sem;
}test_device;*/
static int test_open(struct inode *inode,struct file *filp)
{
/*test_device *dev;*/
int minor=MINOR(inode->i_rdev);
printk(KERN_WARNING"Inside test_open\n");
printk(KERN_WARNING"Minor number is %d\n",minor);
/* MOD_INC_USE_COUNT;*/
}
static int test_release(struct inode *inode,struct file *filp)
{
printk(KERN_WARNING"Inside test_release\n");
return 0;
}
ssize_t test_read(struct file *filp,char *buf,size_t count,loff_t *fpos)
{
/*test_device *dev=filp->private_data;*/
/*test_device *devptr;
devptr->data=data;*/
printk(KERN_WARNING"Inside test_read before count init\n");
count=0;
count=copy_to_user(buf,data,13);
if(count < 0){
printk(KERN_WARNING"data could not be copied\n");
}
else
printk(KERN_WARNING"data copied\n");
}
struct file_operations test_fops={
llseek: NULL,
read: test_read,
write: NULL,
readdir: NULL,
poll: NULL,
ioctl: NULL,
mmap: NULL,
open: test_open,
flush: NULL,
release: test_release,
fsync: NULL,
fasync: NULL,
lock: NULL,
readv: NULL,
writev: NULL,
owner: THIS_MODULE
};
int init_module()
{
/*int count;*/
major=register_chrdev(test_major,"Test",&test_fops);
if(major < 0)
{
printk(KERN_WARNING"cant get major %d\n",test_major);
return -1;
}
else
printk(KERN_WARNING"major number is %d\n",major);
return 0;
}
void cleanup_module()
{
printk("<1>Module dying");
/* MOD_DEC_USE_COUNT;*/
unregister_chrdev(major,"Test");
}
