public inbox for linux-ia64@vger.kernel.org
 help / color / mirror / Atom feed
From: Jeff Woods <kazrak+kernel@cesmail.net>
To: linux-ia64@vger.kernel.org
Subject: Re: segv at strcmp
Date: Wed, 24 Dec 2003 23:44:15 +0000	[thread overview]
Message-ID: <marc-linux-ia64-107230959611195@msgid-missing> (raw)
In-Reply-To: <marc-linux-ia64-107230762310061@msgid-missing>

At 12/24/2003 03:13 PM -0800, umut aymakoglu wrote:
>The segv happens at memcmp() at a line like: 'strcmp(x, "this is 24 chars 
>long")' where x is a char pointer with a length of 7 and the constant has 
>a length of 24. x is located at the first 8 bytes of the last 16 bytes at 
>the end of a non-contiguous shared memory segment. memcmp() segvs when it 
>tries to load 8 bytes from the "r19" register which initially has the 
>address of x and points to the end of the segment when the segv happens.

So are you calling strcmp() or memcmp() ?  If you are calling strcmp(), it 
sounds like the "last 16 bytes" are not null-terminated to be a valid 
string and the strcmp() is running off the end of the memory segment which 
causes it to try address memory to which it doesn't have access.  If you're 
calling memcmp() with a length longer than 16 then it is also running off 
the end of the segment.

--
Jeff Woods <kazrak+kernel@cesmail.net> 



  reply	other threads:[~2003-12-24 23:44 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-12-24 23:13 segv at strcmp umut aymakoglu
2003-12-24 23:44 ` Jeff Woods [this message]
2003-12-25  0:25 ` Luck, Tony
2003-12-25  1:11 ` Zhu, Yi
  -- strict thread matches above, loose matches on Subject: below --
2004-01-05 19:08 umut aymakoglu
2004-01-05 19:19 ` Luck, Tony
2004-01-05 19:52 ` umut aymakoglu
2004-01-05 20:10 ` Luck, Tony
2004-01-05 22:06 ` David Mosberger
2004-01-06  0:04 ` umut aymakoglu
2004-01-06  1:14 ` Luck, Tony
2004-01-06  1:38 ` umut aymakoglu
2004-01-06  2:01 ` Chen, Kenneth W
2004-01-06 19:58 ` umut aymakoglu

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=marc-linux-ia64-107230959611195@msgid-missing \
    --to=kazrak+kernel@cesmail.net \
    --cc=linux-ia64@vger.kernel.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