From: Jan Kratochvil <jan.kratochvil@redhat.com>
To: paawan oza <paawan1982@yahoo.com>
Cc: gdb@sourceware.org
Subject: Re: debugging gdb using gdb
Date: Sun, 20 Feb 2011 08:07:00 -0000 [thread overview]
Message-ID: <20110220080707.GA6601@host1.dyn.jankratochvil.net> (raw)
In-Reply-To: <810666.91200.qm@web112518.mail.gq1.yahoo.com>
On Wed, 16 Feb 2011 04:41:59 +0100, paawan oza wrote:
> during reversible implementation, I am trying to debug arm-gdb using arm-gdb.
> so i connect through telnet terminal and open two different terminals.
> and run both the gdb on target and attach the one gdb with another one.
> the moment I attach another gdb and give continue command, the gdb being
> debugged, looses iis terminal, and I am not able to type anything, and gdb does
> not accept any keyboard input and it hangs.
One of the possibilities is a ptrace kernel bug. For example there was a bug
reproducing only during gdb debugging of gdb (but not via attach):
http://sources.redhat.com/cgi-bin/cvsweb.cgi/~checkout~/tests/ptrace-tests/tests/o_tracevfork-parent.c?cvsroot=systemtap
There are large parts of the ptrace implementation arch-dependent. You can
compare the testsuite results on x86 vs. arm, although the bug you hit there
is most probably not yet convered by it:
cvs -d :pserver:anoncvs:anoncvs@sourceware.org:/cvs/systemtap co ptrace-tests
You can strace (without -f!) the second gdb to see how the ptrace/wait
syscalls behave. Then you can try to minimize the behavior to a testcase for
an arm kernel fix.
(Sure the reason can be also completely different than ptrace.)
Regards,
Jan
next prev parent reply other threads:[~2011-02-20 8:07 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-02-16 3:42 paawan oza
2011-02-16 18:08 ` Michael Snyder
2011-02-17 3:31 ` paawan oza
2011-02-20 8:07 ` Jan Kratochvil [this message]
2011-02-19 4:51 paawan oza
2011-02-19 22:30 ` Michael Snyder
2011-02-21 8:41 ` paawan oza
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=20110220080707.GA6601@host1.dyn.jankratochvil.net \
--to=jan.kratochvil@redhat.com \
--cc=gdb@sourceware.org \
--cc=paawan1982@yahoo.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