From: Pedro Alves <palves@redhat.com>
To: Petr Sumbera <petr.sumbera@oracle.com>, gdb@sourceware.org
Subject: Re: Solaris - procfs: couldn't find pid 32748 (kernel thread 21) in procinfo list
Date: Tue, 2 Jun 2020 18:14:24 +0100 [thread overview]
Message-ID: <7fdd8e25-ccd3-00eb-ae30-b9f8c7604fd8@redhat.com> (raw)
In-Reply-To: <405d3ffb-ea46-57cb-a023-7dece1983fb6@oracle.com>
On 6/2/20 5:30 PM, Petr Sumbera wrote:
> I have modified your change to gdb 9.2 and to correct occurrence (you have added it to second occurrence of 'exited'):
>
> --- ../../gdb-9.2/gdb/procfs.c.orig 2020-06-02 17:10:32.057735432 +0000
> +++ ../../gdb-9.2/gdb/procfs.c 2020-06-02 18:02:45.496117117 +0000
> @@ -2207,9 +2207,10 @@
> if (print_thread_events)
> printf_unfiltered (_("[%s exited]\n"),
> target_pid_to_str (retval).c_str ());
> - delete_thread (find_thread_ptid (retval));
> - status->kind = TARGET_WAITKIND_SPURIOUS;
> - return retval;
> + thread_info *thr = find_thread_ptid (retval);
> + if (thr)
> + delete_thread (thr);
> + goto wait_again;
> }
> else if (syscall_is_exit (pi, what))
> {
>
> But this time exited message repeats forever:
>
> [LWP 24 exited]
> [LWP 24 exited]
> [LWP 24 exited]
Sounds like the LWP is stuck with the status, or the status is
cached. We probably need to resume the process to move it out
of the syscall, I guess. There's this bit in the file, at
another spot we call goto wait_again:
/* How to keep going without returning to wfi: */
target_continue_no_signal (ptid);
goto wait_again;
wfi == wait_for_inferior, the name of a function that used
to be pretty core in infrun.c. Nowadays handle_inferior_event
took the role.
Try doing the same. Like:
delete_thread (find_thread_ptid (this, retval));
target_continue_no_signal (ptid);
goto wait_again;
You may need to split the delete_thread/find_thread bits, or
you may not. I'm not sure.
The TARGET_WAITKIND_SPURIOUS handling in infrun.c also
just calls resume(GDB_SIGNAL_0), so I _think_ this will work as
well as before. I have no idea how this was supposed to handle
the case of an LWP exiting while another one is single
stepping. Looks like we lose the original single-stepping
request. Maybe. Not sure. But doesn't look like we're
making things any worse.
Thanks,
Pedro Alves
next prev parent reply other threads:[~2020-06-02 17:14 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-28 15:29 Petr Sumbera
2020-05-28 16:01 ` Rainer Orth
2020-06-01 12:47 ` Petr Sumbera
2020-06-01 11:39 ` Petr Sumbera
2020-06-01 19:12 ` Pedro Alves
2020-06-02 7:32 ` Petr Sumbera
2020-06-02 14:53 ` Pedro Alves
2020-06-02 16:30 ` Petr Sumbera
2020-06-02 17:14 ` Pedro Alves [this message]
2020-06-03 13:09 ` Petr Sumbera
2020-06-08 9:51 ` Petr Sumbera
2020-06-08 13:47 ` Pedro Alves
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