<table><tr><td style="">ossi added a comment.
</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/D11236">View Revision</a></tr></table><br /><div><div><blockquote style="border-left: 3px solid #8C98B8;
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<div style="font-style: normal;
padding-bottom: 4px;">In <a href="https://phabricator.kde.org/D11236#394363" style="background-color: #e7e7e7;
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color: rgb(107, 116, 140);"><p>Actually the point I removed does not seem to be true any longer. I'm almost certain, that the <tt style="background: #ebebeb; font-size: 13px;">prctrl(PR_SET_PTRACER, ...)</tt> was not required until some time ago when starting DrKonqi as a fork. But now the internal backtrace is not working without. I cannot tell, when that started (currently using kernel 4.20).</p></div>
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<p>that sounds suspicious. i don't think the kernel's behavior did changed, and the process hierarchy presumably didn't, either. the right is handed down the ancestry, and that's irrespective of whether the tracer is a "natural" ancestor or the tracee, or was set via prctl(). maybe your sysctl settings simply changed?</p></div></div><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/D11236#inline-101173">View Inline</a><span style="color: #4b4d51; font-weight: bold;">kcrash.cpp:657</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; "> <span style="color: #74777d">// Wait forever until the started process exits. This code path is executed</span>
</div><div style="padding: 0 8px; margin: 0 4px; background: rgba(251, 175, 175, .7);"> <span style="color: #74777d">// when launching drkonqi. Note that <span class="bright">drk</span>onqi will <span class="bright">stop</span> this process in the meantime<span class="bright">.</span></span>
</div><div style="padding: 0 8px; margin: 0 4px; background: rgba(251, 175, 175, .7);"> <span class="bright"></span><span style="color: #aa4000"><span class="bright">if</span></span><span class="bright"> </span><span class="p"><span class="bright">(</span></span><span class="bright"></span><span class="n"><span class="bright">directly</span></span><span class="bright"></span><span class="p"><span class="bright">)</span></span><span class="bright"> </span><span class="p"><span class="bright">{</span></span>
</div><div style="padding: 0 8px; margin: 0 4px; background: rgba(251, 175, 175, .7);"> <span style="color: #74777d">//if the process was started directly, use waitpid(), as it's a child...</span>
</div><div style="padding: 0 8px; margin: 0 4px; background: rgba(251, 175, 175, .7);"> <span style="color: #aa4000">while</span> <span class="p">(</span><span class="n">waitpid</span><span class="p">(</span><span style="color: #aa2211">-</span><span style="color: #601200">1</span><span class="p">,</span> <span style="color: #aa4000">nullptr</span><span class="p">,</span> <span style="color: #601200">0</span><span class="p">)</span> <span style="color: #aa2211">!=</span> <span class="n">pid</span><span class="p">)</span> <span class="p">{}</span>
</div><div style="padding: 0 8px; margin: 0 4px; background: rgba(251, 175, 175, .7);"> <span class="p">}</span> <span style="color: #aa4000">else</span> <span class="p">{</span>
</div><div style="padding: 0 8px; margin: 0 4px; background: rgba(151, 234, 151, .6);"> <span style="color: #74777d">// when launching drkonqi. Note that <span class="bright">DrK</span>onqi will <span class="bright">SIGSTOP</span> this process in the meantime</span>
</div><div style="padding: 0 8px; margin: 0 4px; background: rgba(151, 234, 151, .6);"> <span class="bright"></span><span style="color: #74777d"><span class="bright">// and a backtrace will end here.</span></span>
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<div style="margin: 8px 0; padding: 0 12px;"><p style="padding: 0; margin: 8px;">ok, so now it's claimed to apply to the entire block. but how can that be? thepollDrKonqiSocket() couldn't possibly be called then ...</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/D11236#inline-101174">View Inline</a><span style="color: #4b4d51; font-weight: bold;">kcrash.cpp:907</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="n">r</span> <span style="color: #aa2211">=</span> <span class="n">poll</span><span class="p">(</span><span style="color: #aa2211">&</span><span class="n">fd</span><span class="p">,</span> <span style="color: #601200">1</span><span class="p">,</span> <span style="color: #601200">1000</span><span class="p">);</span> <span style="color: #74777d">// wait for 1 second for a request by DrKonqi</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">r</span> <span style="color: #aa2211">==</span> <span style="color: #aa2211">-</span><span style="color: #601200">1</span> <span style="color: #aa2211">&&</span> <span class="p">(</span><span class="n">errno</span> <span style="color: #aa2211">==</span> <span class="n">EINTR</span> <span style="color: #aa2211">||</span> <span class="n">errno</span> <span style="color: #aa2211">==</span> <span class="n">EAGAIN</span><span class="p">));</span>
</div><div style="padding: 0 8px; margin: 0 4px; background: rgba(151, 234, 151, .6);"> <span style="color: #74777d">// only continue if POLLIN event returned</span>
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<div style="margin: 8px 0; padding: 0 12px;"><p style="padding: 0; margin: 8px;">remove eagain here as well.</p></div></div></div></div></div><br /><div><strong>REPOSITORY</strong><div><div>R285 KCrash</div></div></div><br /><div><strong>REVISION DETAIL</strong><div><a href="https://phabricator.kde.org/D11236">https://phabricator.kde.org/D11236</a></div></div><br /><div><strong>To: </strong>croick, Frameworks, ossi<br /><strong>Cc: </strong>dfaure, lepagevalleeemmanuel, kde-frameworks-devel, sitter, michaelh, ngraham, bruns<br /></div>