Reading kmem

From: Catalin Patulea
Date: Sun Apr 17 2005 - 14:32:10 EST


Hello,

I'm having trouble reading from /dev/kmem in Linux 2.4.22 and 2.4.25. I have written some code available at http://vv.carleton.ca/~cat/misc/readidt.c. The behavior on both kernel versions is the following:

# ./readidt
idt: 0xffffe000 + 0x07ff
pointer at 0x00000000ffffe400
read: 0

As read returns 0, it seems as if it's reading past the end of file. However, the IDT must be present in the kernel's virtual memory. Also, looking at 2.4.20's read_kmem() (drivers/char/mem.c:215), I don't see how the function could return 0 unless count was 0.

It would be great if follow-ups could be CC'ed to my e-mail address.

Thank you very much for your time,
Catalin

-----------------------------------------
Catalin Patulea VV Volunteer 2002,3
http://vv.carleton.ca/~cat/ VV HI 2004
cat@xxxxxxxxxxxxxx
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