Re: Strange switching [threadname] to secondary mode after exception #0 in kernel-space at 0x80272444

François Legal devel at
Fri Sep 25 18:11:55 CEST 2020

Sorry to come back so late on that topic.
I took some time to write a simple test program, which is attached.

Config is as follows :


Le Vendredi, Août 21, 2020 20:04 CEST, Jan Kiszka <jan.kiszka at> a écrit: 
> On 20.08.20 15:46, François Legal via Xenomai wrote:
> > Using RTNet with multiple interfaces, xenomai 3.1 with linux 4.4
> > Whenever a posix RT thread calls recvmsg (), I get this error.
> > 
> > I could track this down to line 422 in udp.c :     msg = rtnet_get_arg(fd, &_msg, u_msg, sizeof(_msg));
> > 
> > If I disassemble the kernel, the failing instruction (at 0x80272444) is a nop in arm_copy_from_user
> > Am I doing anything wrong ?
> Maybe you are passing an invalid pointer to recvmsg, directly or in its
> message structures. That would cause an exception which is fixed up but
> also reported. Do you get an error in return?
> Jan
> -- 
> Siemens AG, Corporate Technology, CT RDA IOT SES-DE
> Corporate Competence Center Embedded Linux
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