kernelnewbies.kernelnewbies.org archive mirror
 help / color / mirror / Atom feed
From: sengottuvelan.s@gmail.com (Sengottuvelan S)
To: kernelnewbies@lists.kernelnewbies.org
Subject: Cannot get I/O permissions
Date: Fri, 1 Apr 2011 15:32:59 -0700	[thread overview]
Message-ID: <BANLkTikL-Tyeanmu2ehCqh+n-p9QJbaVaA@mail.gmail.com> (raw)
In-Reply-To: <BANLkTimVusN58K-aUpkYmshHKh3Hy8Bb6g@mail.gmail.com>

On Fri, Apr 1, 2011 at 3:32 PM, Sengottuvelan S
<sengottuvelan.s@gmail.com>wrote:

> Hi All,
>
> I am trying to access /dev/mem in my user process. I could not access
> because not a privileged access. I tried to use iopl(3) call in linux 2.6,
> but i am getting unresolved symbol for this.  Is any other way to get access
> in user process. I am not sure how to solve this. Can you someone throw some
> light on this.
>
>    if(iopl(3)){
>         fprintf(stderr, "Cannot get I/O permissions (being root helps)");
>         return -1;
>     }
>
>   if ((fd = open("/dev/mem", O_RDWR | O_SYNC)) < 0) {
>         fprintf(stderr, "Failed to open /dev/mem");
>         return -1;
>     }
>
> --
> Regards,
> S. Sengottuvelan.
>



-- 
Regards,
S. Sengottuvelan.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.kernelnewbies.org/pipermail/kernelnewbies/attachments/20110401/2baba05f/attachment.html 

       reply	other threads:[~2011-04-01 22:32 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <BANLkTimVusN58K-aUpkYmshHKh3Hy8Bb6g@mail.gmail.com>
2011-04-01 22:32 ` Sengottuvelan S [this message]
2011-04-06  3:30   ` Cannot get I/O permissions Pei Lin

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=BANLkTikL-Tyeanmu2ehCqh+n-p9QJbaVaA@mail.gmail.com \
    --to=sengottuvelan.s@gmail.com \
    --cc=kernelnewbies@lists.kernelnewbies.org \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).