Re: [Xenomai-help] Kernel access of bad area with rtdm_event_wait() (MPC8347)

[Jan Kiszka <jan.kiszka@domain.hid>]

Perrine Martignoni wrote:
> Hello,
> 
> I work on a MPC8347 processor and I found out a problem with
> rtdm_event_wait(). I reproduce the problem with a simple code :
> 
> *driver.c* :
> #include <rtdm/rtdm_driver.h>
> 
> MODULE_AUTHOR("P.Martignoni");
> MODULE_LICENSE("GPL");
> 
> #define DEV_FILE_NAME       "DspDev"
> #define DRV_NAME            "DspDrv"
> 
> #define DEV_FILE_DSP            "dspdev0"
> 
> static rtdm_event_t s_ReadEvent;
> 
> static int Open(struct rtdm_dev_context    *p_Context,
>                 rtdm_user_info_t           *p_UserInfo,
>                 int                        Oflags)
> {
>     int ret = 0;
> 
>     rtdm_event_init(&s_ReadEvent,0);
> 
>     // generates an error : Oops : Kernel access of bad area, sig : 11 [#1]
>     rtdm_event_wait(&s_ReadEvent);

General advice: switch on XENO_OPT_DEBUG_RTDM (and IPIPE_DEBUG_CONTEXT)
to catch service invocations from a wrong context, like here.

Your mistake: calling a blocking Xenomai services from non-rt context
(see your registration of Open in t_IdspDevice).

Jan

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