Re: [OpenOCD-user] [openocd-user@lists.sourceforge.net: v0.11.0-rc2. Found bug when stepping or continue with debugger.]

[Antonio B. <bor...@gm...>]

Hi Alexander,

you point to the line
src/server/gdb_server.c:2753  retval = target_poll(target);
but that line is executed only when
src/server/gdb_server.c:2746  retval = target_resume(target, 1, 0, 0, 0);
returns error.

In the logs you have provided I do not see such error returned by
target_resume().
Look like your code calls target_poll() even when target_resume()
returns ERROR_OK!
Can you please clarify this?

So far I cannot replicate this issue, but I do not have an ARM11.
Maybe the problem is in arm11_resume()

Regards
Antonio


On Wed, Feb 24, 2021 at 5:28 PM Paul Fertser <fer...@gm...> wrote:
>
>
> --
> Be free, use free (http://www.gnu.org/philosophy/free-sw.html) software!
> mailto:fer...@gm...
>
>
>
> ---------- Forwarded message ----------
> From: "Габитов Александр Фаритович via OpenOCD-user" <ope...@li...>
> To: ope...@li...
> Cc:
> Bcc:
> Date: Wed, 24 Feb 2021 16:24:20 +0500
> Subject: [OpenOCD-user] v0.11.0-rc2. Found bug when stepping or continue with debugger.
> Hello!
>
> Recently I had to update the program from version 8-rc1 to version 11-rc2(from archive) to support the J-link v9 debugger. While debugging with a new version of the program when stepping, or when starting the program after a breakpoint - the control did not return to the console, while in the console I saw the following lines:
>
>     target halted in ARM state due to breakpoint, current mode: System
>     cpsr: 0x6000011f pc: 0x41703480
>
> I found that the problem is in the function 'gdb_handle_vcont_packet' (gdb_server.c):
>
>     /* simple case, a continue packet */
>     if (parse[0] == 'c') {
>         gdb_running_type = 'c';
>         LOG_DEBUG("target %s continue", target_name(target));
>         log_add_callback(gdb_log_callback, connection);
>         retval = target_resume(target, 1, 0, 0, 0);
>         if (retval == ERROR_TARGET_NOT_HALTED)
>             LOG_INFO("target %s was not halted when resume was requested", target_name(target));
>
>         /* poll target in an attempt to make its internal state consistent */
>         if (retval != ERROR_OK) {
>             retval = target_poll(target);
>             if (retval != ERROR_OK)
>                 LOG_DEBUG("error polling target %s after failed resume", target_name(target));
>         }
>
>         /*
>          * We don't report errors to gdb here, move frontend_state to
>          * TARGET_RUNNING to stay in sync with gdb's expectation of the
>          * target state
>          */
>         gdb_connection->frontend_state = TARGET_RUNNING;
>         target_call_event_callbacks(target, TARGET_EVENT_GDB_START);
>
>         return true;
>     }
>
> I will explain how I did it. I added 3 breakpoints and tried to navigate between them using the continue command. The problem is in string [ retval = target_poll(target); ]. Polling the target here leads to updating it state (if target hits breakpoint before polling), and than when we running frontend it never sees changing of target state. As a result we got target halted but running frontend. The previous version (v0.10.0) works fine, cause it doesnot poll target during process of continue command.
>
> The same problem when i do stepping (over or into).
>
> I should mention that sometimes everything works fine because target hits breakpoint after polling in continue command.
>
> I'll attach console log, debug log and CFG file.
>
> Note: I added some more debug meassages to source codes and most of them i have marked with label - Gabitov: or gabitov:, but some are unmarked (for example - 'enter DSCR_CORE_HALTED'). So if you find unrecognized message in debug log probably it's mine. The source codes version is 0.11.0-rc2 (from archive - https://sourceforge.net/projects/openocd/files/openocd/0.11.0-rc2/openocd-0.11.0-rc2.zip).
>
> I will provide more detailed information if needed.
>
> ------------------
>
> Alexander Gabitov, Engineer, LLC PLANAR
>
>
> _______________________________________________
> OpenOCD-user mailing list
> Ope...@li...
> https://lists.sourceforge.net/lists/listinfo/openocd-user