<table><tr><td style="">bruns requested changes to this revision.<br />bruns added inline comments.<br />This revision now requires changes to proceed.
</td><a style="text-decoration: none; padding: 4px 8px; margin: 0 8px 8px; float: right; color: #464C5C; font-weight: bold; border-radius: 3px; background-color: #F7F7F9; background-image: linear-gradient(to bottom,#fff,#f1f0f1); display: inline-block; border: 1px solid rgba(71,87,120,.2);" href="https://phabricator.kde.org/D17816">View Revision</a></tr></table><br /><div><strong>INLINE COMMENTS</strong><div><div style="margin: 6px 0 12px 0;"><div style="border: 1px solid #C7CCD9; border-radius: 3px;"><div style="padding: 0; background: #F7F7F7; border-color: #e3e4e8; border-style: solid; border-width: 0 0 1px 0; margin: 0;"><div style="color: #74777d; background: #eff2f4; padding: 6px 8px; overflow: hidden;"><a style="float: right; text-decoration: none;" href="https://phabricator.kde.org/D17816#inline-164866">View Inline</a><span style="color: #4b4d51; font-weight: bold;">file_unix.cpp:141</span></div>
<div style="font: 11px/15px "Menlo", "Consolas", "Monaco", monospace; white-space: pre-wrap; clear: both; padding: 4px 0; margin: 0;"><div style="padding: 0 8px; margin: 0 4px; background: rgba(151, 234, 151, .6);"> <span style="color: #74777d">// Get the list of keys</span>
</div><div style="padding: 0 8px; margin: 0 4px; background: rgba(151, 234, 151, .6);"> <span style="color: #aa4000">ssize_t</span> <span class="n">listlen</span> <span style="color: #aa2211">=</span> <span style="color: #601200">512</span><span class="p">;</span>
</div><div style="padding: 0 8px; margin: 0 4px; background: rgba(151, 234, 151, .6);"> <span class="n">QByteArray</span> <span style="color: #004012">keylist</span><span class="p">(</span><span class="n">listlen</span><span class="p">,</span> <span class="n">Qt</span><span style="color: #aa2211">::</span><span class="n">Uninitialized</span><span class="p">);</span>
</div></div></div>
<div style="margin: 8px 0; padding: 0 12px;"><p style="padding: 0; margin: 8px;">The idea is almost right, the implementation is wrong.</p>
<div class="remarkup-code-block" style="margin: 12px 0;" data-code-lang="text" data-sigil="remarkup-code-block"><pre class="remarkup-code" style="font: 11px/15px "Menlo", "Consolas", "Monaco", monospace; padding: 12px; margin: 0; background: rgba(71, 87, 120, 0.08);">1. set listlen to 0
2. resize keylist to listlen
3. execute flistxattr with size = keylist.size();
4a. if (3.) returns listlen > 0 and keylist.size() == 0, go to (2.)
4b. if (3.) returns listlen > 0 and keylist.size() > 0 -> break
4c. if (3.) returns listlen == -1 and errno == ERANGE, set listlen to 0 and go to (2.)
4d. if (3.) returns listlen == -1 and errno == ENOTSUP -> return
4e. if (3.) returns listlen == 0 -> return
5. resize keylist to listlen, the list may shrink between flistxattr calls.</pre></div></div></div><br /><div style="border: 1px solid #C7CCD9; border-radius: 3px;"><div style="padding: 0; background: #F7F7F7; border-color: #e3e4e8; border-style: solid; border-width: 0 0 1px 0; margin: 0;"><div style="color: #74777d; background: #eff2f4; padding: 6px 8px; overflow: hidden;"><a style="float: right; text-decoration: none;" href="https://phabricator.kde.org/D17816#inline-164864">View Inline</a><span style="color: #4b4d51; font-weight: bold;">file_unix.cpp:153</span></div>
<div style="font: 11px/15px "Menlo", "Consolas", "Monaco", monospace; white-space: pre-wrap; clear: both; padding: 4px 0; margin: 0;"><div style="padding: 0 8px; margin: 0 4px; background: rgba(151, 234, 151, .6);"> <span style="color: #aa4000">if</span> <span class="p">(</span><span class="n">errno</span> <span style="color: #aa2211">==</span> <span class="n">ERANGE</span><span class="p">)</span> <span class="p">{</span>
</div><div style="padding: 0 8px; margin: 0 4px; background: rgba(151, 234, 151, .6);"> <span class="n">keylist</span><span class="p">.</span><span class="n">resize</span><span class="p">(</span><span class="n">listlen</span> <span style="color: #aa2211">+</span> <span style="color: #601200">512</span><span class="p">);</span>
</div><div style="padding: 0 8px; margin: 0 4px; background: rgba(151, 234, 151, .6);"> <span class="p">}</span>
</div></div></div>
<div style="margin: 8px 0; padding: 0 12px;"><p style="padding: 0; margin: 8px;">as listlen is -1 here, you always resize to 511 ...</p></div></div><br /><div style="border: 1px solid #C7CCD9; border-radius: 3px;"><div style="padding: 0; background: #F7F7F7; border-color: #e3e4e8; border-style: solid; border-width: 0 0 1px 0; margin: 0;"><div style="color: #74777d; background: #eff2f4; padding: 6px 8px; overflow: hidden;"><a style="float: right; text-decoration: none;" href="https://phabricator.kde.org/D17816#inline-164867">View Inline</a><span style="color: #4b4d51; font-weight: bold;">file_unix.cpp:163</span></div>
<div style="font: 11px/15px "Menlo", "Consolas", "Monaco", monospace; white-space: pre-wrap; clear: both; padding: 4px 0; margin: 0;"><div style="padding: 0 8px; margin: 0 4px; background: rgba(151, 234, 151, .6);"> <span class="p">}</span>
</div><div style="padding: 0 8px; margin: 0 4px; background: rgba(151, 234, 151, .6);"> <span class="p">}</span> <span style="color: #aa4000">while</span> <span class="p">(</span><span class="n">listlen</span> <span style="color: #aa2211">==</span> <span style="color: #aa2211">-</span><span style="color: #601200">1</span> <span style="color: #aa2211">&&</span> <span class="n">errno</span> <span style="color: #aa2211">==</span> <span class="n">ERANGE</span><span class="p">);</span>
</div></div></div>
<div style="margin: 8px 0; padding: 0 12px;"><p style="padding: 0; margin: 8px;">man 2 flistxattr:</p>
<blockquote style="border-left: 3px solid #a7b5bf; color: #464c5c; font-style: italic; margin: 4px 0 12px 0; padding: 4px 12px; background-color: #f8f9fc;"><p style="padding: 0; margin: 8px;">In addition, the errors documented in stat(2) can also occur.</p></blockquote>
<p style="padding: 0; margin: 8px;">So any error but ERANGE will exit the loop, and you will have bogus keylist contents.</p>
<p style="padding: 0; margin: 8px;">Do <tt style="background: #ebebeb; font-size: 13px;">return false</tt> on any error but ERANGE in the loop.</p>
<p style="padding: 0; margin: 8px;">After the loop (i.e. when listlen is guaranteed to be > 0), resize keylist to listlen, the list may shrink.</p></div></div><br /><div style="border: 1px solid #C7CCD9; border-radius: 3px;"><div style="padding: 0; background: #F7F7F7; border-color: #e3e4e8; border-style: solid; border-width: 0 0 1px 0; margin: 0;"><div style="color: #74777d; background: #eff2f4; padding: 6px 8px; overflow: hidden;"><a style="float: right; text-decoration: none;" href="https://phabricator.kde.org/D17816#inline-164869">View Inline</a><span style="color: #4b4d51; font-weight: bold;">file_unix.cpp:173</span></div>
<div style="font: 11px/15px "Menlo", "Consolas", "Monaco", monospace; white-space: pre-wrap; clear: both; padding: 4px 0; margin: 0;"><div style="padding: 0 8px; margin: 0 4px; background: rgba(151, 234, 151, .6);"> <span style="color: #74777d">// For each key</span>
</div><div style="padding: 0 8px; margin: 0 4px; background: rgba(151, 234, 151, .6);"> <span class="n">keylist</span><span class="p">.</span><span class="n">squeeze</span><span class="p">();</span>
</div><div style="padding: 0 8px; margin: 0 4px; background: rgba(151, 234, 151, .6);"> <span style="color: #aa4000">while</span> <span class="p">(</span><span class="n">keyPtr</span> <span style="color: #aa2211">!=</span> <span class="n">keylist</span><span class="p">.</span><span class="n">cend</span><span class="p">())</span> <span class="p">{</span>
</div></div></div>
<div style="margin: 8px 0; padding: 0 12px;"><p style="padding: 0; margin: 8px;">Thats bad. Thats really bad.</p>
<p style="padding: 0; margin: 8px;">squeeze may reallocate. This invalidates keyPtr.</p></div></div><br /><div style="border: 1px solid #C7CCD9; border-radius: 3px;"><div style="padding: 0; background: #F7F7F7; border-color: #e3e4e8; border-style: solid; border-width: 0 0 1px 0; margin: 0;"><div style="color: #74777d; background: #eff2f4; padding: 6px 8px; overflow: hidden;"><a style="float: right; text-decoration: none;" href="https://phabricator.kde.org/D17816#inline-164871">View Inline</a><span style="color: #4b4d51; font-weight: bold;">file_unix.cpp:186</span></div>
<div style="font: 11px/15px "Menlo", "Consolas", "Monaco", monospace; white-space: pre-wrap; clear: both; padding: 4px 0; margin: 0;"><div style="padding: 0 8px; margin: 0 4px; background: rgba(151, 234, 151, .6);"> <span style="color: #aa4000">ssize_t</span> <span class="n">valuelen</span> <span style="color: #aa2211">=</span> <span style="color: #601200">512</span><span class="p">;</span>
</div><div style="padding: 0 8px; margin: 0 4px; background: rgba(151, 234, 151, .6);"> <span class="n">QByteArray</span> <span style="color: #004012">value</span><span class="p">(</span><span class="n">valuelen</span><span class="p">,</span> <span class="n">Qt</span><span style="color: #aa2211">::</span><span class="n">Uninitialized</span><span class="p">);</span>
</div><div style="padding: 0 8px; margin: 0 4px; background: rgba(151, 234, 151, .6);"> <span style="color: #aa4000">do</span> <span class="p">{</span>
</div></div></div>
<div style="margin: 8px 0; padding: 0 12px;"><p style="padding: 0; margin: 8px;"><tt style="background: #ebebeb; font-size: 13px;">QByteArray value</tt> should be created outside the keyPtr loop.</p>
<p style="padding: 0; margin: 8px;">This reduces the calls to malloc for the QByteArray data storage.</p>
<p style="padding: 0; margin: 8px;">Then for each attribute, do a <tt style="background: #ebebeb; font-size: 13px;">value.resize(value.capacity)</tt>.</p></div></div><br /><div style="border: 1px solid #C7CCD9; border-radius: 3px;"><div style="padding: 0; background: #F7F7F7; border-color: #e3e4e8; border-style: solid; border-width: 0 0 1px 0; margin: 0;"><div style="color: #74777d; background: #eff2f4; padding: 6px 8px; overflow: hidden;"><a style="float: right; text-decoration: none;" href="https://phabricator.kde.org/D17816#inline-164870">View Inline</a><span style="color: #4b4d51; font-weight: bold;">file_unix.cpp:196</span></div>
<div style="font: 11px/15px "Menlo", "Consolas", "Monaco", monospace; white-space: pre-wrap; clear: both; padding: 4px 0; margin: 0;"><div style="padding: 0 8px; margin: 0 4px; background: rgba(151, 234, 151, .6);"> <span style="color: #aa4000">if</span> <span class="p">(</span><span class="n">valuelen</span> <span style="color: #aa2211">==</span> <span style="color: #aa2211">-</span><span style="color: #601200">1</span> <span style="color: #aa2211">&&</span> <span class="n">errno</span> <span style="color: #aa2211">==</span> <span class="n">ERANGE</span><span class="p">)</span> <span class="p">{</span>
</div><div style="padding: 0 8px; margin: 0 4px; background: rgba(151, 234, 151, .6);"> <span class="n">value</span><span class="p">.</span><span class="n">resize</span><span class="p">(</span><span class="n">valuelen</span> <span style="color: #aa2211">+</span> <span style="color: #601200">512</span><span class="p">);</span>
</div><div style="padding: 0 8px; margin: 0 4px; background: rgba(151, 234, 151, .6);"> <span class="p">}</span>
</div></div></div>
<div style="margin: 8px 0; padding: 0 12px;"><p style="padding: 0; margin: 8px;">-1 + 512 = 511 ...</p>
<p style="padding: 0; margin: 8px;">Should be <tt style="background: #ebebeb; font-size: 13px;">value.resize(value.size() + 512)</tt> or something similar.</p></div></div><br /><div style="border: 1px solid #C7CCD9; border-radius: 3px;"><div style="padding: 0; background: #F7F7F7; border-color: #e3e4e8; border-style: solid; border-width: 0 0 1px 0; margin: 0;"><div style="color: #74777d; background: #eff2f4; padding: 6px 8px; overflow: hidden;"><a style="float: right; text-decoration: none;" href="https://phabricator.kde.org/D17816#inline-164872">View Inline</a><span style="color: #4b4d51; font-weight: bold;">file_unix.cpp:198</span></div>
<div style="font: 11px/15px "Menlo", "Consolas", "Monaco", monospace; white-space: pre-wrap; clear: both; padding: 4px 0; margin: 0;"><div style="padding: 0 8px; margin: 0 4px; background: rgba(151, 234, 151, .6);"> <span class="p">}</span>
</div><div style="padding: 0 8px; margin: 0 4px; background: rgba(151, 234, 151, .6);"> <span class="p">}</span> <span style="color: #aa4000">while</span> <span class="p">(</span><span class="n">valuelen</span> <span style="color: #aa2211">==</span> <span style="color: #aa2211">-</span><span style="color: #601200">1</span> <span style="color: #aa2211">&&</span> <span class="n">errno</span> <span style="color: #aa2211">==</span> <span class="n">ERANGE</span><span class="p">);</span>
</div></div></div>
<div style="margin: 8px 0; padding: 0 12px;"><p style="padding: 0; margin: 8px;">Again, valuelen may be -1 here ...</p></div></div></div></div></div><br /><div><strong>REPOSITORY</strong><div><div>R241 KIO</div></div></div><br /><div><strong>REVISION DETAIL</strong><div><a href="https://phabricator.kde.org/D17816">https://phabricator.kde.org/D17816</a></div></div><br /><div><strong>To: </strong>cochise, dfaure, chinmoyr, bruns, Frameworks, tmarshall, usta<br /><strong>Cc: </strong>usta, scheirle, anthonyfieroni, tmarshall, arrowd, cfeck, bruns, phidrho, dhaumann, funkybomber, abika, pino, davidedmundson, ngraham, atha.kane, spoorun, nicolasfella, kde-frameworks-devel, LeGast00n, cblack, michaelh<br /></div>