Content-class: urn:content-classes:message
MIME-Version: 1.0
Content-Type: text/plain;
	charset="us-ascii"
Content-Transfer-Encoding: 8BIT
Subject: RE: Walking all the physical memory in an x86 system
Date: Tue, 30 Nov 2004 14:36:27 -0700
Message-ID: <C863B68032DED14E8EBA9F71EB8FE4C2058057A1@azsmsx406>
Thread-Topic: Walking all the physical memory in an x86 system
Thread-Index: AcTXI3+uzPbOQJnvROKMZe0B4m8APwAAJd8g
From: "Hanson, Jonathan M" <jonathan.m.hanson@intel.com>
To: <jengelh@linux01.gwdg.de>
Cc: <linux-kernel@vger.kernel.org>
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1188
Lines: 39


-----Original Message-----
From: Jan Engelhardt [mailto:jengelh@linux01.gwdg.de] 
Sent: Tuesday, November 30, 2004 2:28 PM
To: Hanson, Jonathan M
Cc: linux-kernel@vger.kernel.org
Subject: RE: Walking all the physical memory in an x86 system

>[Jon M. Hanson] I can read /dev/mem from a userspace application as
root
>with no problems and print out what it sees. However, things are not so
>simple from a kernel module as I just can't call open() and read() on
>/dev/mem because no such functions are exported from the kernel. Is
>there a way to read the contents of /dev/mem from a kernel module?

You can use filp_open().


Jan Engelhardt
-- 
ENOSPC

[Jon M. Hanson] I tried the filp_open() approach like this:

struct file *mem_fd;

mem_fd = filp_open("/dev/mem", O_RDONLY | O_LARGEFILE, 0);

I then have a check if IS_ERR(mem_fd) is true immediately afterwards
along with a printk saying it failed. This condition is true when I ran
it.


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/