CINXE.COM

<?xml version="1.0" encoding="UTF-8" standalone="yes"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>LKML: "linux-os \(Dick Johnson\)": Re: How to enable/disable security features on mmap() ?</title><link href="/css/message.css" rel="stylesheet" type="text/css" /><link href="/css/wrap.css" rel="alternate stylesheet" type="text/css" title="wrap" /><link href="/css/nowrap.css" rel="stylesheet" type="text/css" title="nowrap" /><link href="/favicon.ico" rel="shortcut icon" /><script src="/js/simple-calendar.js" type="text/javascript"></script><script src="/js/styleswitcher.js" type="text/javascript"></script><link rel="alternate" type="application/rss+xml" title="lkml.org : last 100 messages" href="/rss.php" /><link rel="alternate" type="application/rss+xml" title="lkml.org : last messages by "linux-os \(Dick Johnson\)"" href="/groupie.php?aid=29670" /><script> var _paq = window._paq = window._paq || []; /* tracker methods like "setCustomDimension" should be called before "trackPageView" */ _paq.push(["setDoNotTrack", true]); _paq.push(["disableCookies"]); _paq.push(['trackPageView']); _paq.push(['enableLinkTracking']); (function() { var u="//m.lkml.org/"; _paq.push(['setTrackerUrl', u+'matomo.php']); _paq.push(['setSiteId', '1']); var d=document, g=d.createElement('script'), s=d.getElementsByTagName('script')[0]; g.async=true; g.src=u+'matomo.js'; s.parentNode.insertBefore(g,s); })(); </script></head><body onload="es.jasper.simpleCalendar.init();" itemscope="itemscope" itemtype="http://schema.org/BlogPosting"><table border="0" cellpadding="0" cellspacing="0"><tr><td width="180" align="center"><a href="/"><img style="border:0;width:135px;height:32px" src="/images/toprowlk.gif" alt="lkml.org" /></a></td><td width="32">聽</td><td class="nb"><div><a class="nb" href="/lkml"> [lkml]</a> 聽 <a class="nb" href="/lkml/2005"> [2005]</a> 聽 <a class="nb" href="/lkml/2005/12"> [Dec]</a> 聽 <a class="nb" href="/lkml/2005/12/8"> [8]</a> 聽 <a class="nb" href="/lkml/last100"> [last100]</a> 聽 <a href="/rss.php"><img src="/images/rss-or.gif" border="0" alt="RSS Feed" /></a></div><div>Views: <a href="#" class="nowrap" onclick="setActiveStyleSheet('wrap');return false;">[wrap]</a><a href="#" class="wrap" onclick="setActiveStyleSheet('nowrap');return false;">[no wrap]</a> 聽 <a class="nb" href="/lkml/mheaders/2005/12/8/118" onclick="this.href='/lkml/headers'+'/2005/12/8/118';">[headers]</a>聽 <a href="/lkml/bounce/2005/12/8/118">[forward]</a>聽 </div></td><td width="32">聽</td></tr><tr><td valign="top"><div class="es-jasper-simpleCalendar" baseurl="/lkml/"></div><div class="threadlist">Messages in this thread</div><ul class="threadlist"><li class="root"><a href="/lkml/2005/12/8/92">First message in thread</a></li><li><a href="/lkml/2005/12/8/108">Arjan van de Ven</a><ul><li><a href="/lkml/2005/12/8/112">Emmanuel Fleury</a><ul><li><a href="/lkml/2005/12/8/116">Emmanuel Fleury</a></li><li class="origin"><a href="/lkml/2005/12/8/121">"linux-os \(Dick Johnson\)"</a><ul><li><a href="/lkml/2005/12/8/121">Emmanuel Fleury</a><ul><li><a href="/lkml/2005/12/8/126">Arjan van de Ven</a></li></ul></li><li><a href="/lkml/2005/12/8/123">Arjan van de Ven</a><ul><li><a href="/lkml/2005/12/8/132">"linux-os \(Dick Johnson\)"</a></li></ul></li></ul></li></ul></li></ul></li></ul></td><td width="32" rowspan="2" class="c" valign="top"><img src="/images/icornerl.gif" width="32" height="32" alt="/" /></td><td class="c" rowspan="2" valign="top" style="padding-top: 1em"><table><tr><td><table><tr><td class="lp">Subject</td><td class="rp" itemprop="name">Re: How to enable/disable security features on mmap() ?</td></tr><tr><td class="lp">Date</td><td class="rp" itemprop="datePublished">Thu, 8 Dec 2005 10:16:38 -0500</td></tr><tr><td class="lp">From</td><td class="rp" itemprop="author">"linux-os \(Dick Johnson\)" <></td></tr></table></td><td></td></tr></table><pre itemprop="articleBody"><br />On Thu, 8 Dec 2005, Emmanuel Fleury wrote:<br /><br />> Arjan van de Ven wrote:<br />>><br />>> well it's a /proc/ variable already! So you can just turn it off<br />>> entirely at runtime. (what is better is that you use the setarch program<br />>> to turn it off for selected programs though...)<br />><br />> I knew it was a stupid question ! I fooled myself once more ! ;-)<br />> I'll take a look at this familly of variables and at the proc entries.<br />><br />> Thanks a lot !<br />> --<br /><br />> Emmanuel Fleury<br /><br />In reference to the random-stack patch....<br /><br />Executing the following program on linux-2.6.13.4:<br /><br />#include <stdio.h><br /><br />int main()<br />{<br /> int foo;<br /> printf("%p\n", &foo);<br /> return 0;<br />}<br /><br />... a few thousand times and sorting its output shows<br />the stack varies from:<br /> 0xbf7fe144 -> 0xbffff674<br /><br />Isn't this too much? I thought the random-stack patch was<br />only supposed to vary it a page or 64k at most. This looks<br />like some broken logic because it varies almost 8 megabytes!<br />No wonder some of my user's database programs sometimes seg-fault<br />and other times work perfectly fine. I think this is incorrect<br />and shows a serious bug (misbehavior).<br /><br />Cheers,<br />Dick Johnson<br />Penguin : Linux version 2.6.13.4 on an i686 machine (5589.55 BogoMips).<br />Warning : 98.36% of all statistics are fiction.<br />.<br /><br />****************************************************************<br />The information transmitted in this message is confidential and may be privileged. Any review, retransmission, dissemination, or other use of this information by persons or entities other than the intended recipient is prohibited. If you are not the intended recipient, please notify Analogic Corporation immediately - by replying to this message or by sending an email to DeliveryErrors@analogic.com - and destroy all copies of this information, including any attachments, without reading or disclosing them.<br /><br />Thank you.<br />-<br />To unsubscribe from this list: send the line "unsubscribe linux-kernel" in<br />the body of a message to majordomo@vger.kernel.org<br />More majordomo info at <a href="http://vger.kernel.org/majordomo-info.html">http://vger.kernel.org/majordomo-info.html</a><br />Please read the FAQ at <a href="http://www.tux.org/lkml/">http://www.tux.org/lkml/</a><br /><br /></pre></td><td width="32" rowspan="2" class="c" valign="top"><img src="/images/icornerr.gif" width="32" height="32" alt="\" /></td></tr><tr><td align="right" valign="bottom"> 聽 </td></tr><tr><td align="right" valign="bottom">聽</td><td class="c" valign="bottom" style="padding-bottom: 0px"><img src="/images/bcornerl.gif" width="32" height="32" alt="\" /></td><td class="c">聽</td><td class="c" valign="bottom" style="padding-bottom: 0px"><img src="/images/bcornerr.gif" width="32" height="32" alt="/" /></td></tr><tr><td align="right" valign="top" colspan="2"> 聽 </td><td class="lm">Last update: 2005-12-08 16:20 聽聽 [from the cache]<br />漏2003-2020 <a href="http://blog.jasper.es/"><span itemprop="editor">Jasper Spaans</span></a>|hosted at <a href="https://www.digitalocean.com/?refcode=9a8e99d24cf9">Digital Ocean</a> and my Meterkast|<a href="http://blog.jasper.es/categories.html#lkml-ref">Read the blog</a></td><td>聽</td></tr></table><script language="javascript" src="/js/styleswitcher.js" type="text/javascript"></script></body></html>