From: Chris Friesen <cfriesen@nortelnetworks.com>
To: linux-os@analogic.com
Cc: Bryn Reeves <breeves@redhat.com>, Rik van Riel <riel@redhat.com>,
Andrew Morton <akpm@osdl.org>,
linux-kernel@vger.kernel.org,
James Antill <james.antill@redhat.com>
Subject: Re: don't let mmap allocate down to zero
Date: Wed, 26 Jan 2005 13:13:11 -0600 [thread overview]
Message-ID: <41F7EBC7.5030108@nortelnetworks.com> (raw)
In-Reply-To: <Pine.LNX.4.61.0501261325540.18301@chaos.analogic.com>
linux-os wrote:
> The seg-fault you get when you de-reference a pointer to NULL
> is caused by the kernel. You are attempting to access memory
> that has not been mapped into your address space. Once that
> memory gets mmap()ed, you will no longer get a seg-fault.
> Again, the seg-fault has nothing to do with 'C'. It's an
> implementation behavior that can be changed with mmap().
The segfault *does* have something to do with C. The standard says that
the result of dereferencing a NULL pointer is *undefined*. Not
implementation-defined, but undefined. Anything relying on
dereferencing NULL pointers is not valid C code.
Chris
next prev parent reply other threads:[~2005-01-27 2:01 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-01-26 16:18 don't let mmap allocate down to zero Rik van Riel
2005-01-26 16:38 ` linux-os
2005-01-26 17:05 ` Sytse Wielinga
2005-01-26 17:34 ` Chris Friesen
2005-01-26 17:57 ` Bryn Reeves
2005-01-26 18:37 ` linux-os
2005-01-26 18:54 ` Rik van Riel
2005-01-26 19:09 ` linux-os
2005-01-26 19:13 ` Chris Friesen [this message]
2005-01-26 19:08 ` Chris Friesen
2005-01-26 18:10 ` Olivier Galibert
2005-01-26 18:20 ` linux-os
2005-01-26 18:31 ` Olivier Galibert
2005-01-26 18:39 ` linux-os
2005-01-26 19:41 ` Arjan van de Ven
2005-01-26 20:26 ` Andy Isaacson
2005-01-26 20:42 ` Rik van Riel
2005-01-26 22:12 ` Kyle Moffett
2005-01-26 23:31 ` Brian Gerst
2005-01-26 17:25 ` William Lee Irwin III
2005-01-27 5:09 ` William Lee Irwin III
2005-01-27 5:18 ` Dave Jones
2005-01-27 5:28 ` William Lee Irwin III
2005-01-27 9:29 ` Mikael Pettersson
2005-01-27 12:52 ` William Lee Irwin III
2005-01-27 14:25 ` Russell King
2005-01-27 15:12 ` William Lee Irwin III
2005-01-27 19:22 ` Rik van Riel
2005-01-27 20:44 ` William Lee Irwin III
2005-01-27 20:58 ` Rik van Riel
2005-01-27 21:13 ` William Lee Irwin III
2005-01-27 21:28 ` Rik van Riel
2005-01-28 5:30 ` William Lee Irwin III
2005-01-28 13:01 ` Rik van Riel
2005-01-28 14:14 ` Hugh Dickins
2005-01-28 14:26 ` William Lee Irwin III
2005-01-28 15:41 ` Rik van Riel
2005-01-28 15:53 ` Hugh Dickins
2005-01-27 21:58 ` linux-os
2005-01-27 14:26 ` Mikael Pettersson
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=41F7EBC7.5030108@nortelnetworks.com \
--to=cfriesen@nortelnetworks.com \
--cc=akpm@osdl.org \
--cc=breeves@redhat.com \
--cc=james.antill@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-os@analogic.com \
--cc=riel@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.