Watchpoints not being handled correctly on arm it seems

Watchpoints not being handled correctly on arm it seems

[François Legal]

Hello,

Working with xenomai 3.2.3 with linux 5.4 on Zynq7000.

While debugging my application, with GDB, if a watchpoint hits when in a xenomai RT thread, the machine hangs.
If I connect the JTAG probe, I get core 1 halted with message "Synchronous Watchpoint", with PC being on the instruction that should have trigged the watchpoint. From that point, I can never get GDB or the app to continue. I can (using the JTAG debugger) hit continue, but it seems the app stays hung (even kill -9 does not terminate it and I have to reboot the target.

Can anybody help ?

Thanks in advance

François

Re: Watchpoints not being handled correctly on arm it seems

[Jan Kiszka]

On 08.11.23 17:58, François Legal wrote:
> Hello,
> 
> Working with xenomai 3.2.3 with linux 5.4 on Zynq7000.
> 
> While debugging my application, with GDB, if a watchpoint hits when in a xenomai RT thread, the machine hangs.
> If I connect the JTAG probe, I get core 1 halted with message "Synchronous Watchpoint", with PC being on the instruction that should have trigged the watchpoint. From that point, I can never get GDB or the app to continue. I can (using the JTAG debugger) hit continue, but it seems the app stays hung (even kill -9 does not terminate it and I have to reboot the target.
> 
> Can anybody help ?

Do you see the same issue with 5.10 or newer (Dovetail patch series), or
with 4.19 (SLTS-based I-pipe)?

Jan

-- 
Siemens AG, Technology
Linux Expert Center

Re: Watchpoints not being handled correctly on arm it seems

[François Legal]

Le Jeudi, Novembre 09, 2023 12:22 CET, Jan Kiszka <jan.kiszka@siemens.com> a écrit:

> On 08.11.23 17:58, François Legal wrote:
> > Hello,
> >
> > Working with xenomai 3.2.3 with linux 5.4 on Zynq7000.
> >
> > While debugging my application, with GDB, if a watchpoint hits when in a xenomai RT thread, the machine hangs.
> > If I connect the JTAG probe, I get core 1 halted with message "Synchronous Watchpoint", with PC being on the instruction that should have trigged the watchpoint. From that point, I can never get GDB or the app to continue. I can (using the JTAG debugger) hit continue, but it seems the app stays hung (even kill -9 does not terminate it and I have to reboot the target.
> >
> > Can anybody help ?
>
> Do you see the same issue with 5.10 or newer (Dovetail patch series), or
> with 4.19 (SLTS-based I-pipe)?
>

I can't tell for 5.10 as I have some custom driver for custom hardware that I did not port to dovetail/evl yet. The same is true for 4.19 (which lacks features I need) and I'm not sure I can easily test that. It was OK in 4.4 though

François

> Jan
>
> --
> Siemens AG, Technology
> Linux Expert Center
>