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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> kernelnewbies-bounces@kernelnewbies.org [mailto:kernelnewbies-bounces@kernelnewbies.org]
<b>On Behalf Of </b>KASHISH BHATIA<br>
<b>Sent:</b> Friday, August 14, 2015 6:09 AM<br>
<b>To:</b> Pranay Srivastava<br>
<b>Cc:</b> kernelnewbies<br>
<b>Subject:</b> Re: signals handling in kernel<o:p></o:p></span></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt">I want to write a module which will spawn two kthreads where kthread-1 will send signal X to kthread-2 and kthread-2 has registered a signal handler to catch signal X. When the signal X is caught by kthread-2,
it will execute its signal handler.<o:p></o:p></p>
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<p class="MsoNormal">Just am exploring signal handing and its intricacies, so thought of this exercise. Is it possible ?<o:p></o:p></p>
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<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">I think signal handlers of the sort you describe are a feature of user space. If a process (kthread or user space) that is blocked on a call to wait_event_interruptible()
is sent a signal, the call to wait_event_interruptible() will return with an –ERESTARTSYS so you can add “signal handler” code there. But I don’t think it’s possible to register a signal handler from kernel space like you can using the signal() or sigaction()
systems calls that you can use from user space.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">If somebody else thinks different, please do pipe up. This signal stuff in the kernel has always been a bit mysterious to me.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Jeff Haran<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
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