From mboxrd@z Thu Jan  1 00:00:00 1970
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Date: Mon, 10 Jan 2011 17:24:28 +0100
From: Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>
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Subject: Re: [Xenomai-help] Correct use of xeno_sigshadow_install()
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To: Peter Soetens <peter@domain.hid>
Cc: xenomai-help <xenomai@xenomai.org>

Peter Soetens wrote:
> Hi,
> 
> A while ago, I was advised to call xeno_sigshadow_install() after a library 
> installed a sigwinch signal handler (I believe this was Xenomai 2.5.1). Could 
> it be that this is no longer supported in recent versions ? What is the 
> correct way to avoid a segfault if an application installed a sigwinch handler 
> after Xenomai did ?

I think we already answered that at the time, but if you install your
own sigwinch handler, you should:
- register it with the SA_SIGINFO flag
- call xeno_sigwinch_handler and consider that the signal is for the
application only if this function returns 0.

If you can not do that, then redefine SIGSHADOW in
include/asm-generic/syscall.h to a different value, and recompile both
Xenomai user-space and kernel-space support. Note however that when
starting applications in gdb you will then have to type:

handle <the_new_signal> pass nostop print

If you want to be able to debug Xenomai applications.

-- 
                                                                Gilles.