2005-04-17 19:27:32

by Catalin Patulea

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Subject: Reading kmem

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
[email protected]