From: Matt Chapman <matthewc@cse.unsw.edu.au>
To: linux-ia64@vger.kernel.org
Subject: Re: [RFC] prevent "dd if=/dev/mem" crash
Date: Sat, 18 Oct 2003 02:01:52 +0000 [thread overview]
Message-ID: <marc-linux-ia64-106644274924705@msgid-missing> (raw)
In-Reply-To: <marc-linux-ia64-106642876514553@msgid-missing>
On Fri, Oct 17, 2003 at 06:48:33PM -0700, David Mosberger wrote:
> >>>>> On Fri, 17 Oct 2003 17:49:55 -0700, Andrew Morton <akpm@osdl.org> said:
>
> Andrew> We _want_ to be able to read mmio ranges via /dev/mem, don't
> Andrew> we? I guess it has never come up because everyone uses
> Andrew> kmem.
>
> I just don't see how making a "dd if=/dev/mem" safe and allowing
> access to arbitrary physical memory can go to together. Given that
> /dev/mem _is_ being used for accessing mmio space, is it really worth
> bothering trying to make such a "dd" safe?
Usually people who want to access MMIO devices would use mmap rather
than read/write.
But I do agree that the current semantics are not unreasonable and the
user should think about what they're doing before accessing random parts
of /dev/mem.
Matt
next prev parent reply other threads:[~2003-10-18 2:01 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-10-17 22:10 [RFC] prevent "dd if=/dev/mem" crash Bjorn Helgaas
2003-10-17 22:19 ` Luck, Tony
2003-10-17 22:23 ` Matt Mackall
2003-10-17 22:40 ` Andreas Schwab
2003-10-17 22:50 ` Andrew Morton
2003-10-17 23:25 ` Bjorn Helgaas
2003-10-17 23:55 ` Andrew Morton
2003-10-18 0:15 ` William Lee Irwin III
2003-10-18 0:21 ` David Mosberger
2003-10-18 0:49 ` Andrew Morton
2003-10-18 1:31 ` Matt Chapman
2003-10-18 1:41 ` Andrew Morton
2003-10-18 1:48 ` David Mosberger
2003-10-18 2:01 ` Andrew Morton
2003-10-18 2:01 ` Matt Chapman [this message]
2003-10-19 11:25 ` Eric W. Biederman
2003-10-19 18:17 ` Pavel Machek
2003-10-19 19:01 ` William Lee Irwin III
2003-10-20 15:17 ` Bjorn Helgaas
2003-10-20 17:42 ` Bjorn Helgaas
2003-10-20 18:48 ` David Mosberger
2003-10-23 8:33 ` Martin Pool
2003-10-23 9:31 ` Zoltan Menyhart
2003-10-23 21:05 ` Bjorn Helgaas
-- strict thread matches above, loose matches on Subject: below --
2003-10-17 22:19 Luck, Tony
2003-10-17 22:40 ` Andreas Schwab
2003-10-17 22:10 Bjorn Helgaas
2003-10-17 22:23 ` Matt Mackall
2003-10-17 22:50 ` Andrew Morton
2003-10-17 23:25 ` Bjorn Helgaas
2003-10-17 23:55 ` Andrew Morton
2003-10-18 0:15 ` William Lee Irwin III
2003-10-18 0:21 ` David Mosberger
2003-10-18 0:49 ` Andrew Morton
2003-10-18 1:31 ` Matt Chapman
2003-10-18 1:41 ` Andrew Morton
2003-10-18 1:48 ` David Mosberger
2003-10-18 2:01 ` Andrew Morton
2003-10-18 2:01 ` Matt Chapman
2003-10-19 11:25 ` Eric W. Biederman
2003-10-19 19:01 ` William Lee Irwin III
2003-10-20 15:17 ` Bjorn Helgaas
2003-10-20 18:48 ` David Mosberger
2003-10-20 17:42 ` Bjorn Helgaas
2003-10-23 21:05 ` Bjorn Helgaas
2003-10-19 18:17 ` Pavel Machek
2003-10-23 8:33 ` Martin Pool
2003-10-23 9:31 ` Zoltan Menyhart
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