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From: Don Raikes <don.raikes@oracle.com>
To: "Speakup is a screen review system for Linux."
	<speakup@linux-speakup.org>
Subject: RE: OT: kernel oops
Date: Thu, 18 Jul 2013 10:16:33 -0700 (PDT)	[thread overview]
Message-ID: <e84841b6-6522-49f9-97b0-32a37b04a760@default> (raw)
In-Reply-To: <87mwpjx3ae.fsf@mushroom.PK5001Z>

Chris,

Thanks it worked like a charm.
No more segmentation faults and I was able to print the contents of the array I copied from userspace!

Wow I should have come here earlier in the week instead of beating my head against the wall for so long :-)
-----Original Message-----
From: Chris Brannon [mailto:chris@the-brannons.com] 
Sent: Thursday, July 18, 2013 9:05 AM
To: Speakup is a screen review system for Linux.
Subject: Re: OT: kernel oops

Don Raikes <don.raikes@oracle.com> writes:

> The section of code that is having problems looks like this:
*SNIP*
> if (copy_from_user(&tbuf, buf, count))

This line is your problem.  You are passing a pointer-to-pointer-to-character (char **) as the first argument to copy_from_user, but you should be passing char * instead.  So ditch the ampersand, and all will be right with the world!
I could give you a thorough explanation of why this is failing, if you like, but to make a long story short, this line of code is smashing the stack!

I'm always happy to help.
-- Chris
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  parent reply	other threads:[~ UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
 Don Raikes
 ` Jason White
 ` Chris Brannon
   ` Don Raikes
   ` Don Raikes [this message]
   ` Jason White
     ` Don Raikes
       ` Jason White
         ` Don Raikes
           ` Jason White
             ` Don Raikes
               ` Jason White

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