From: Yao Qi <qiyaoltc@gmail.com>
To: Antoine Tremblay <antoine.tremblay@ericsson.com>
Cc: Pedro Alves <palves@redhat.com>, gdb-patches@sourceware.org
Subject: Re: [PATCH 0/9 V3] Use reinsert breakpoint for vCont;s
Date: Thu, 24 Nov 2016 21:55:00 -0000 [thread overview]
Message-ID: <20161124215510.pbsobdtj6niycjhd@localhost> (raw)
In-Reply-To: <wwok37ikrgmq.fsf@ericsson.com>
On Mon, Nov 21, 2016 at 10:34:44AM -0500, Antoine Tremblay wrote:
> > Thread 1 either sees the original instruction on address A or the
> > breakpoint instruction. Unless ptrace read/write 32-bit is not
> > atomic, IOW, partial ptrace write result is visible to other
> > threads, I don't see why we get SIGILL here.
>
> I think this is the problem, ptrace read/write doesn't seem to be
> atomic, and thread 1 sees some half written memory. (Given that we get
> SIGILL/SIGSEGV issues)
We need to check in linux-arm-kernel@.
>
> Did you have any reference suggesting it was atomic ?
>
No.
> While testing it seems to be atomic for 32bit writes but in thumb mode
> with a 16 byte write, it is not.
I think you meant "16 bit write". Why is that?
>
> Given the SIGILL/SIGSEG I get maybe that one is 2 writes of 1 byte ?
> I'll have to dig in the ptrace code I guess.
>
It is good to get some a clear answer instead of ambiguous speculation.
I think we need to ask in linux-arm-kernel@
--
Yao
next prev parent reply other threads:[~2016-11-24 21:55 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-30 14:09 Yao Qi
2016-06-30 14:09 ` [PATCH 5/9] Switch current_thread to lwp's thread in install_software_single_step_breakpoints Yao Qi
2016-06-30 14:09 ` [PATCH 7/9] Enqueue signal even when resuming threads Yao Qi
2016-07-01 15:06 ` Pedro Alves
2016-07-01 16:45 ` Yao Qi
2016-07-01 16:55 ` Pedro Alves
2016-07-01 17:01 ` Pedro Alves
2016-06-30 14:09 ` [PATCH 9/9] Support vCont s and S actions with software single step Yao Qi
2016-06-30 14:09 ` [PATCH 1/9] Pass breakpoint type in set_breakpoint_at Yao Qi
2016-06-30 14:09 ` [PATCH 3/9] Refactor clone_all_breakpoints Yao Qi
2016-06-30 14:09 ` [PATCH 2/9] Create sub classes of 'struct breakpoint' Yao Qi
2016-06-30 14:09 ` [PATCH 4/9] Make reinsert_breakpoint thread specific Yao Qi
2016-06-30 14:09 ` [PATCH 8/9] Use reinsert_breakpoint for vCont;s Yao Qi
2016-07-01 15:07 ` Pedro Alves
2016-07-05 8:15 ` Yao Qi
2016-07-21 8:38 ` Yao Qi
2016-07-21 10:02 ` Pedro Alves
2016-06-30 14:09 ` [PATCH 6/9] Use enqueue_pending_signal in linux_resume_one_thread Yao Qi
2016-07-21 11:18 ` [PATCH 0/9 V3] Use reinsert breakpoint for vCont;s Yao Qi
2016-11-14 19:14 ` Antoine Tremblay
2016-11-21 12:08 ` Yao Qi
[not found] ` <wwok37ikrgmq.fsf@ericsson.com>
2016-11-23 19:03 ` Antoine Tremblay
2016-11-24 21:55 ` Yao Qi [this message]
2016-11-25 12:22 ` Antoine Tremblay
2016-11-25 13:13 ` Antoine Tremblay
2016-11-25 13:35 ` Antoine Tremblay
2016-11-25 13:44 ` Pedro Alves
2016-11-25 13:57 ` Antoine Tremblay
2016-11-25 14:28 ` Antoine Tremblay
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20161124215510.pbsobdtj6niycjhd@localhost \
--to=qiyaoltc@gmail.com \
--cc=antoine.tremblay@ericsson.com \
--cc=gdb-patches@sourceware.org \
--cc=palves@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox