From mboxrd@z Thu Jan  1 00:00:00 1970
Date: Thu, 23 Apr 2015 16:34:07 +0200
From: Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>
Message-ID: <20150423143407.GI7109@hermes.click-hack.org>
References: <1429798709.21270.3.camel@lx-henry>
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Subject: Re: [Xenomai] segfaults when using xenomai shared library
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To: Henry Bausley <hbausley@deltatau.com>
Cc: "Xenomai@xenomai.org" <xenomai@xenomai.org>

On Thu, Apr 23, 2015 at 07:18:29AM -0700, Henry Bausley wrote:
> I am seeing a intermittent segfaults when linking to a shared library
> that links with xenomai.
> 
> I sometimes get
> [30354.351344] projpp[25002]: segfault at c ip b751bcfa sp b770c238
> error 4 in libpthread-2.19.so[b7511000+18000]
> 
> My shared library libppmac.so contains a single function and absolutely
> nothing else
> 
> int Test(void)
> {
>   return 1 + 1;
> }
> 
> ldd returns
> 
> root@10.34.9.73:/opt/ppmac/libppmac# ldd libppmac.so 
> 	linux-gate.so.1 =>  (0xb7779000)
> 	libpthread_rt.so.1 => /usr/lib/libpthread_rt.so.1 (0xb774e000)
> 	libxenomai.so.0 => /usr/lib/libxenomai.so.0 (0xb7746000)
> 	libc.so.6 => /lib/i386-linux-gnu/libc.so.6 (0xb7596000)
> 	libpthread.so.0 => /lib/i386-linux-gnu/libpthread.so.0 (0xb757a000)
> 	librt.so.1 => /lib/i386-linux-gnu/librt.so.1 (0xb7571000)
> 	/lib/ld-linux.so.2 (0xb777a000)
> 
> My application does not even call the function in the shared library.
> Its code is as follows
> 
> #include <pthread.h>
> #include <dlfcn.h>
> 
> int Test(void);
> 
> int main(int argc, char *argv[])
> {
>   printf("pthread_setschedparam(pthread_self(),SCHED_OTHER,&param);\n");
> }
> 
> int CallLibraryToBreak(void)
> {
>   Test();
> }
> 
> The application does not segfault if I do not link the xenomai libraries
> ie. 

There is a case you seem to not have tested. What about linking with
xenomai libraries without linking to libppmac.so ?

-- 
					    Gilles.