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From: bugghy <bugghy@SAFe-mail.net>
To: linux-kernel@vger.kernel.org, bugghy@SAFe-mail.net
Subject: address of int80 idt
Date: Thu, 15 Jul 2004 18:27:38 +0000	[thread overview]
Message-ID: <1089916056.15617.14.camel@illusion.com> (raw)

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	Hy, I'm working on an improved rk detector and I've got some problems.
I use this code to get the address of int80's idt (interrupt description
table)

struct idtr
{
  unsigned short limit;
  unsigned int base;
} __attribute__ ((packed));


void find_int80()
{
  struct idtr idtr;
  memset(&idtr, 0, sizeof(struct idtr));
  asm ("sidt %0" : "=m" (idtr));
  printf("idtr.base=0x%08x\n", idtr.base);
  kmem_read(fd, &idt, sizeof(idt), idtr.base + 0x80 * sizeof(struct
idt));
  ...
}

The problem is that on some kernels 2.4.22 (and I think on 2.6.7, 2.2.26
and 2.4.26 too) on vmware sidt returns a bogus address for idtr.base:
idtr.base=0xffc6a370 (2.4.22) 


If I try to read from /dev/kmem from this address it doesn't work.

I printed the contents of struct idtr after the sidt call, here it is:
ff 07 70 a3 c6 ff

What could be the problem? Is there any solution for this? Most of the
time works but not on my (2.4.22) vmware. And if this is not a bug, what
would be another method of doing this ?

PS: Please cc me the answer as I'm not on this mailling list.

	Thanks in advance,
		Bugghy


-- 
------------------------
- Software is like sex -
-     it's better when -
-          it's free   -
-     Linus Torvalds   -
------------------------

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             reply	other threads:[~2004-07-15 15:29 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-07-15 18:27 bugghy [this message]
  -- strict thread matches above, loose matches on Subject: below --
2004-07-15 15:38 address of int80 idt Petr Vandrovec

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