difference in behavior between 2.6.18 and 2.6.33 while using mknod

greplinux · 05-04-2012, 03:54 PM

Hi All,

I am using mknod function in my driver to create a device file.

Code:

 mknod("/dev/sampledev", S_IFCHR|S_IRUGO|S_IWUGO, MKDEV(SAMPLE_MAJOR, 0));

While loading this driver in 2.6.18 kernel the permission i get is as following:

Quote:

crw-rw-rw-

In 2.6.33:

Quote:

crw-r--r--

I havent done any changes in the code. can you guys explain this difference in behavior?

Thanks in advance,

business_kid · 05-05-2012, 12:55 PM

Umask?? Permissions??

Ananda Bbau · 05-06-2012, 07:03 AM

Hi All

Me also has got the same write permission problem while using the mknod for kernel 2.6.32. I checked the umask values and permissions all. Please any one can try and give the answer to that..

Please if anyone help for that, it will be better to me.

Thanks,
G.Ananda Babu.

business_kid · 05-06-2012, 12:57 PM

If everything else is the same, the difference might just be the one you mentioned - 2.6.18 vs 2.6.33. I would compare options also. If IFCHR, S_IRUGO, & S_IWUGO are variables, check them with

Quote:

echo $IFCHR $S_IRUGO $S_IWUGO

MKDEV is what? If it's a script

Quote:

cat MKDEV