This is the mail archive of the
mailing list for the GDB project.
Re: [PATCH 3/3] Wait for target to stop before running agent commands
- From: Pedro Alves <palves at redhat dot com>
- To: Gary Benson <gbenson at redhat dot com>, gdb-patches at sourceware dot org
- Cc: Doug Evans <dje at google dot com>
- Date: Fri, 19 Sep 2014 17:16:02 +0100
- Subject: Re: [PATCH 3/3] Wait for target to stop before running agent commands
- Authentication-results: sourceware.org; auth=none
- References: <1411034346-868-1-git-send-email-gbenson at redhat dot com> <1411034346-868-4-git-send-email-gbenson at redhat dot com>
On 09/18/2014 10:59 AM, Gary Benson wrote:
> This commit fixes a bug on where agent_run_command is called on
> GNU/Linux targets that may not have stopped yet.
> * linux-nat.c (linux_child_static_tracepoint_markers_by_strid):
> Use target_stop_and_wait in place of target_stop.
> gdb/ChangeLog | 5 +++++
> gdb/linux-nat.c | 2 +-
> 2 files changed, 6 insertions(+), 1 deletions(-)
> diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c
> index 5a82d23..f2895ff 100644
> --- a/gdb/linux-nat.c
> +++ b/gdb/linux-nat.c
> @@ -4458,7 +4458,7 @@ linux_child_static_tracepoint_markers_by_strid (struct target_ops *self,
> ptid_t ptid = ptid_build (pid, 0, 0);
> /* Pause all */
> - target_stop (ptid);
> + target_stop_and_wait (ptid);
More would be needed for fix this fully.
Unlike the comment above suggests, target_stop_and_wait only
waits for one thread to stop, not all.
See the gdbserver version (run_inferior_command) -- this is also
missing uninserting breakpoints after fully pausing the target.
If we handle this internally to linux-nat.c, then similarly
to gdbserver's version, this could use
stop_callback/stop_wait_callback to leave pending any events
that pausing might trip on. Then we'd need to be careful to
only re-resume threads that were already resumed before, and
leave those with pending events stopped. If we want to
use existing target methods, then we need to teach gdb's
struct thread_info layer about leaving events pending, like in:
Alternative, we can would promote target_stop_and_wait to
a real target method that handles the leaving of events pending,
like gdbserver's pause_all/unpause_all methods.