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List: cfe-dev
Subject: Re: [cfe-dev] About Address San...
From: John Criswell <criswell () illinois ! edu>
Date: 2012-05-28 15:20:33
Message-ID: 4FC397C1.1020601 () illinois ! edu
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On 5/28/12 3:27 AM, Umesh Kalappa wrote:
>
> Hi John and All,
> Thank you for the your inputs,we tried running Safecode with Liblto
> on our code base few weeks back,I'm very sorry to say this that we
> feel that safecode is not so stable and output is not so informative
> ,Please correct us if i'm wrong here.
>
Can you be more specific about how SAFECode was not stable or its output
was not informative? Even though you've decided not to use it, we'd
like to know details on what you think is wrong so that we can determine
if it can be improved.
Also, may I ask what program you were compiling with SAFECode? If it's
open source, we might give SAFECode a spin on it ourselves.
Two other things that might influence your decision:
1) Did you compile programs with the -g option? If not, then SAFECode's
error reports will not provide any useful debugging output.
2) Will Dietz recently made some extraordinary memory consumption
improvements to the code used in the libLTO module. If memory
consumption was the problem you were having with SAFECode's libLTO, that
is fixed now.
-- John T.
>
> Thanks Again.
>
> ~Umesh
>
> On May 25, 2012 7:54 PM, "John Criswell" <criswell@illinois.edu
> <mailto:criswell@illinois.edu>> wrote:
>
> On 5/25/12 6:57 AM, Umesh Kalappa wrote:
>> Hi All ,
>>
>> I'm not sure the question is relevant to the forum,My apologies
>> if not
>>
>> We are trying to instrument our code with ASan(Clang) to find
>> the memory errors and we see that the application execution halts
>> when the Asan check finds the memory issue at the
>> being. Which mean we need to fix the issue then compile and
>> execute the instrumented code again to find the next issue and
>> so on .Which is fine.
>>
>> We would like to know that there is any option to clang or llvm
>> ,Where we can say to Asan to log output to the file and continue
>> to execute the instrumented application instead of halting the
>> same.Like Valgrind memcheck has.So we can whole or almost issues
>> in the log .
>
> SAFECode's clang supports this feature in its debug mode; I think
> the number of failures before termination is configurable via a
> command-line option. The price that it pays is extra performance
> overhead and an inability to detect the dereference of
> out-of-bounds pointers in external library code.
>
> SAFECode also supports a feature to log error reports to a
> separate file instead of on stderr.
>
> If you find the continued execution feature useful, please let all
> of us know. Since these features make design tradeoffs, it's
> useful to learn what is useful and what isn't.
>
> That said, if ASan is finding a genuine memory safety error, you
> should fix that bug.
>
> -- John T.
>
>>
>> For you reference
>> I'm using the clang version as
>>
>> [root@localhost ~]# clang --version
>> clang version 3.2 (trunk)
>> Target: i386-pc-linux-gnu
>> Thread model: posix
>>
>>
>> On OS
>>
>> Centos -6
>> [root@localhost ~]# uname -a
>> Linux localhost.localdomain 2.6.32-220.el6.i686 #1 SMP Tue
>> Dec 6 16:15:40 GMT 2011 i686 i686 i386 GNU/Linux
>>
>>
>> Thanks
>> ~Umesh
>>
>>
>>
>>
>> _______________________________________________
>> cfe-dev mailing list
>> cfe-dev@cs.uiuc.edu <mailto:cfe-dev@cs.uiuc.edu>
>> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev
>
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On 5/28/12 3:27 AM, Umesh Kalappa wrote:
<blockquote
cite="mid:CAGfacvTpjR8qUXZ3ra9=GMHiGYR6mzpny=ai9bOmq56kp6ASZg@mail.gmail.com"
type="cite">
<meta http-equiv="Content-Type" content="text/html;
charset=ISO-8859-1">
<p>Hi John and All,<br>
Thank you for the your inputs,we tried running Safecode with
Liblto on our code base few weeks back,I'm very sorry to say
this that we feel that safecode is not so stable and output is
not so informative ,Please correct us if i'm wrong here.</p>
</blockquote>
<br>
Can you be more specific about how SAFECode was not stable or its
output was not informative? Even though you've decided not to use
it, we'd like to know details on what you think is wrong so that we
can determine if it can be improved.<br>
<br>
Also, may I ask what program you were compiling with SAFECode? If
it's open source, we might give SAFECode a spin on it ourselves.<br>
<br>
Two other things that might influence your decision:<br>
<br>
1) Did you compile programs with the -g option? If not, then
SAFECode's error reports will not provide any useful debugging
output.<br>
<br>
2) Will Dietz recently made some extraordinary memory consumption
improvements to the code used in the libLTO module. If memory
consumption was the problem you were having with SAFECode's libLTO,
that is fixed now.<br>
<br>
-- John T.<br>
<br>
<br>
<blockquote
cite="mid:CAGfacvTpjR8qUXZ3ra9=GMHiGYR6mzpny=ai9bOmq56kp6ASZg@mail.gmail.com"
type="cite">
<p><br>
</p>
<p>Thanks Again.</p>
<p>~Umesh</p>
<div class="gmail_quote">On May 25, 2012 7:54 PM, "John Criswell"
<<a moz-do-not-send="true"
href="mailto:criswell@illinois.edu" \
target="_blank">criswell@illinois.edu</a>> wrote:<br type="attribution">
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000"> On 5/25/12 6:57 AM,
Umesh Kalappa wrote:
<blockquote type="cite"> Hi All ,
<div><br>
</div>
<div>I'm not sure the question is relevant to the forum,My
apologies if not </div>
<div><br>
</div>
<div>We are trying to instrument our code with <span><font
face="arial, sans-serif"><span
style="line-height:16px">ASan(Clang) to find the
memory errors and we see that the
application execution halts when the Asan check
finds the memory issue at the \
being. Which mean we need to fix the issue then compile and
execute the instrumented code again to find the
next issue and so on .Which is fine.</span></font></span></div>
<div><span><font face="arial, sans-serif"><span
style="line-height:16px"><br>
</span></font></span></div>
<div><span><font face="arial, sans-serif"><span
style="line-height:16px">We would like to know
that there is any option to clang or llvm ,Where
we can say to Asan to log output to the file and
continue to execute the instrumented application
instead of halting the same.Like Valgrind memcheck
has.So we can whole or almost issues in the log \
.</span></font></span></div> </blockquote>
<br>
SAFECode's clang supports this feature in its debug mode; I
think the number of failures before termination is
configurable via a command-line option. The price that it
pays is extra performance overhead and an inability to
detect the dereference of out-of-bounds pointers in external
library code.<br>
<br>
SAFECode also supports a feature to log error reports to a
separate file instead of on stderr.<br>
<br>
If you find the continued execution feature useful, please
let all of us know. Since these features make design
tradeoffs, it's useful to learn what is useful and what
isn't.<br>
<br>
That said, if ASan is finding a genuine memory safety error,
you should fix that bug.<br>
<br>
-- John T.<br>
<br>
<blockquote type="cite">
<div><span><font face="arial, sans-serif"><span
style="line-height:16px"><br>
</span></font></span></div>
<div><span><font face="arial, sans-serif"><span
style="line-height:16px">For you \
reference </span></font></span></div> <div><font face="arial, sans-serif"><span
style="line-height:16px">I'm using the clang version
as </span></font></div>
<blockquote style="margin:0 0 0
40px;border:none;padding:0px">
<div><font face="arial, sans-serif"><span
style="line-height:16px">
<div> [root@localhost ~]# clang --version</div>
</span></font></div>
<div><font face="arial, sans-serif"><span
style="line-height:16px">
<div>clang version 3.2 (trunk)</div>
</span></font></div>
<div><font face="arial, sans-serif"><span
style="line-height:16px">
<div> Target: i386-pc-linux-gnu</div>
</span></font></div>
<div><font face="arial, sans-serif"><span
style="line-height:16px">
<div>Thread model: posix</div>
</span></font></div>
</blockquote>
<div><font face="arial, sans-serif"><span
style="line-height:16px">
<div> <br>
</div>
</span></font></div>
<div><font face="arial, sans-serif"><span
style="line-height:16px">On OS </span></font></div>
<blockquote style="margin:0 0 0
40px;border:none;padding:0px">
<div><font face="arial, sans-serif"><span
style="line-height:16px">Centos -6 </span></font></div>
<div><font face="arial, sans-serif"><span
style="line-height:16px">
<div>[root@localhost ~]# uname -a</div>
</span></font></div>
<div><font face="arial, sans-serif"><span
style="line-height:16px">
<div>Linux localhost.localdomain
2.6.32-220.el6.i686 #1 SMP Tue Dec 6 16:15:40
GMT 2011 i686 i686 i386 GNU/Linux</div>
</span></font></div>
</blockquote>
<div><font face="arial, sans-serif"><span
style="line-height:16px">
<div><br>
</div>
</span></font></div>
<div><span
style="font-family:arial,sans-serif;line-height:16px">Thanks </span></div>
<div> <font face="arial, sans-serif"><span
style="line-height:16px">~Umesh </span></font></div>
<div><font face="arial, sans-serif"><span
style="line-height:16px"><br>
</span></font></div>
<div><span><font face="arial, sans-serif"><span
style="line-height:16px"><br>
</span></font></span></div>
<br>
<fieldset></fieldset>
<br>
<pre>_______________________________________________
cfe-dev mailing list
<a moz-do-not-send="true" href="mailto:cfe-dev@cs.uiuc.edu" \
target="_blank">cfe-dev@cs.uiuc.edu</a> <a moz-do-not-send="true" \
href="http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev" \
target="_blank">http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev</a> </pre>
</blockquote>
<br>
</div>
</blockquote>
</div>
</blockquote>
<br>
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