From: greg@kroah.com (Greg KH)
To: kernelnewbies@lists.kernelnewbies.org
Subject: Any successful story of debugging linux 4.13 with qemu 2.10 and gdb 8.01?
Date: Thu, 21 Sep 2017 09:21:43 +0200 [thread overview]
Message-ID: <20170921072143.GA4588@kroah.com> (raw)
In-Reply-To: <20170920192917.lg33kitgd4tqh4bx@judith.localdomain>
On Wed, Sep 20, 2017 at 09:29:17PM +0200, jjDaNiMoTh wrote:
> On 20/09/17 at 11:20am, ??? wrote:
> > 2017-09-20 4:18 GMT-04:00 jjDaNiMoTh <jjdanimoth@gmail.com>:
> > > Hello all,
> > >
> > > As the title says, any of you have successfully tried to debug Linux
> > > 4.13 with QEMU?
>
> > I encountered this problem in my debian testing. Any "break" or
> > "hbreak" point is not triggered
> > even if I set breakpoint at "start_kernel".
> [cut]
>
> So, after two weeks of a headache I took the courage to send an email
> here, and after only 3 hours after the email (!!!) I found the cause of
> the problem.
>
> Without being too long, the problem is KALSR. You have to disable it
> disabling the kernel option "Randomize the address of the kernel image (KASLR)",
> inside Processor type and features. In this way, gdb can translate
> all the symbols correctly (symbols <-> addresses).
>
> I really don't know how the developers test their code... because there
> is no evidence for this.
Why do you think that it requires developers to use a debugger and qemu
to test their code? I've never used a debugger on the kernel in all of
my years of kernel development...
Glad you found a solution and posted it.
greg k-h
next prev parent reply other threads:[~2017-09-21 7:21 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-20 8:18 Any successful story of debugging linux 4.13 with qemu 2.10 and gdb 8.01? jjDaNiMoTh
2017-09-20 15:20 ` 慕冬亮
2017-09-20 19:29 ` jjDaNiMoTh
2017-09-21 7:21 ` Greg KH [this message]
2017-09-21 7:29 ` Saket Sinha
2017-09-21 8:43 ` jjDaNiMoTh
2017-09-21 9:01 ` Greg KH
2017-09-21 17:08 ` 慕冬亮
2017-09-22 6:09 ` Saket Sinha
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=20170921072143.GA4588@kroah.com \
--to=greg@kroah.com \
--cc=kernelnewbies@lists.kernelnewbies.org \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.