From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: root@chaos.analogic.com
Cc: "Srinivas G." <srinivasg@esntechnologies.co.in>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: Having problem with mmap system call!!!
Date: Thu, 16 Sep 2004 14:31:36 +0100 [thread overview]
Message-ID: <1095341494.22744.26.camel@localhost.localdomain> (raw)
In-Reply-To: <Pine.LNX.4.53.0409160958070.12146@chaos>
On Iau, 2004-09-16 at 15:07, Richard B. Johnson wrote:
> if((vp = mmap((caddr_t) HINT, len, PROT, FLAGS, fd, addr)) == SHM_FAIL)
> {
> fprintf(stderr, "Can't access shared memory\n");
> exit(EXIT_FAILURE);
SHM_FAIL is the wrong error check btw.
It is much better to do this in the driver than do nasty user mode hacks
using /dev/mem. When you do it kernel driver side you end up with a
cleaner mmap interface, a sensible permissions model and the hardware
device pages mapped directly and nicely into the app
next prev parent reply other threads:[~2004-09-16 14:40 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <4EE0CBA31942E547B99B3D4BFAB348111078FE@mail.esn.co.in>
2004-09-16 14:07 ` Richard B. Johnson
2004-09-16 13:31 ` Alan Cox [this message]
2004-09-16 14:54 ` Richard B. Johnson
2004-09-16 15:57 ` Alan Cox
2004-09-16 18:13 ` Richard B. Johnson
2004-09-16 20:01 ` Alan Cox
2004-09-16 14:42 Srinivas G.
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