[uml-devel] Starting uml with the debugger

[uml-devel] Starting uml with the debugger

[Etay Meiri]

[-- Attachment #1: Type: text/plain, Size: 396 bytes --]

Hi,

I'm trying to start uml under the controller of gdb using the following
command:

./vmlinux mem=128m ubda=root_fs.fc4_client ubdb=swap_client con=xterm
eth0=tuntap,,,10.10.20.10 <http://10.10.20.10> debug

uml is started ok but there is no sigh of the debugger.

Any idea?

Thanks,

--
------------------------------------------------------
Etay Meiri
etay.meiri@gmail.com

[-- Attachment #2: Type: text/html, Size: 511 bytes --]

Re: [uml-devel] Starting uml with the debugger

[Jeff Dike]

On Mon, Oct 17, 2005 at 07:09:21PM +0200, Etay Meiri wrote:
> Hi,
> 
> I'm trying to start uml under the controller of gdb using the following
> command:

What version?

> ./vmlinux mem=128m ubda=root_fs.fc4_client ubdb=swap_client con=xterm
> eth0=tuntap,,,10.10.20.10 <http://10.10.20.10> debug

WTF is <http://10.10.20.10>?

If this thing is new enough to have skas0, then just disable CONFIG_MODE_TT
and gdb it normally.

				Jeff


-------------------------------------------------------
This SF.Net email is sponsored by:
Power Architecture Resource Center: Free content, downloads, discussions,
and more. http://solutions.newsforge.com/ibmarch.tmpl
_______________________________________________
User-mode-linux-devel mailing list
User-mode-linux-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel

Re: [uml-devel] Starting uml with the debugger

[Etay Meiri]

[-- Attachment #1: Type: text/plain, Size: 820 bytes --]

On 10/17/05, Jeff Dike <jdike@addtoit.com> wrote:
>
> On Mon, Oct 17, 2005 at 07:09:21PM +0200, Etay Meiri wrote:
> > Hi,
> >
> > I'm trying to start uml under the controller of gdb using the following
> > command:
>
> What version?


2.6.13 with 2.6.13-bs2 patch.

> ./vmlinux mem=128m ubda=root_fs.fc4_client ubdb=swap_client con=xterm
> > eth0=tuntap,,,10.10.20.10 <http://10.10.20.10> <http://10.10.20.10>
> debug
>
> WTF is <http://10.10.20.10>?


hmm...looks like copy&paste problem. ignore it, it was not in the command
line.

If this thing is new enough to have skas0, then just disable CONFIG_MODE_TT
> and gdb it normally.


Will it still run if my host kernel is not skas enabled?



--
------------------------------------------------------
Etay Meiri
etay.meiri@gmail.com

[-- Attachment #2: Type: text/html, Size: 1607 bytes --]

Re: [uml-devel] Starting uml with the debugger

[Henrik Nordstrom]

On Mon, 17 Oct 2005, Etay Meiri wrote:

>> If this thing is new enough to have skas0, then just disable 
>> CONFIG_MODE_TT and gdb it normally.
>
>
> Will it still run if my host kernel is not skas enabled?

Yes.

SKAS0 is implementing memory management usign the same principles as SKAS, 
but without support from the host kernel. Performance is not as good as 
"real" SKAS, but the good thing is that to the main parts of the UML 
kernel memory management there is no difference other than performance and 
also that the SKAS model is behaving much better in terms of being a host 
process. Due to the better behaviour of UML in SKAS0 mode gdb can be used 
directly on the kernel just as you gdb any other application.

TT mode on the other hand implements memory (and even process) management 
very differently, behaving very oddly in terms of what a host process 
normally does. For this reason you can't gdb TT mode directly and instead 
have to use the debug option asking TT mode to gdb itself with some very 
magic tricks.

Regards
Henrik





-------------------------------------------------------
This SF.Net email is sponsored by:
Power Architecture Resource Center: Free content, downloads, discussions,
and more. http://solutions.newsforge.com/ibmarch.tmpl
_______________________________________________
User-mode-linux-devel mailing list
User-mode-linux-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel

Re: [uml-devel] Starting uml with the debugger

[Rob Landley]

On Monday 17 October 2005 12:53, Jeff Dike wrote:
> If this thing is new enough to have skas0, then just disable CONFIG_MODE_TT
> and gdb it normally.

I'm curious: now that skas0 mode works, when does tt mode start to go away?

(Obviously, making tls work might be nice first...)

Rob


-------------------------------------------------------
This SF.Net email is sponsored by:
Power Architecture Resource Center: Free content, downloads, discussions,
and more. http://solutions.newsforge.com/ibmarch.tmpl
_______________________________________________
User-mode-linux-devel mailing list
User-mode-linux-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel

Re: [uml-devel] Starting uml with the debugger

[Blaisorblade]

On Tuesday 18 October 2005 03:38, Rob Landley wrote:
> On Monday 17 October 2005 12:53, Jeff Dike wrote:
> > If this thing is new enough to have skas0, then just disable
> > CONFIG_MODE_TT and gdb it normally.

> I'm curious: now that skas0 mode works, when does tt mode start to go away?

I really don't want TT mode to go away.

Reason 1, developers need to be able to enable SMP. Or the locking will break 
even more. And in these two days, with the new (and better) lock debugging of 
2.6.14-rc (from Ingo), I've seen enough bugs to let me scared.

And I simply tested "uml_mconsole <umid> eth1=mcast".

Say, the uml_net_interrupt(), when holding the iface spinlock, can call, in 
the failure path, uml_net_close(), which calls the interrupt again.

Said that, I also have plans (from one year at least) to jail TT mode in a 
faster mode (i.e. with segment limits). I was descouraged, but the 
motivations behind that turned out to be mostly wrong (a supposed "bad 
performance"), and Xen uses it.

However, that's for the memory layout. For the rest I'd take normal SKAS flow. 
So, this would be a SKAS mode for everything, except that it would be like 
2.5G/1G instead of 3G/3G (if you know about 4G/4G in Fedora from Ingo vs. 
3G/1G in vanilla kernels, you should get what I mean. If not, search google 
or lwn.net about 4G/4G).

> (Obviously, making tls work might be nice first...)

I've been stopped by debugging problems, but now I workarounded GDB problems I 
can debug simple problems very easily.

TLS is more difficult, as you need to disassemble the faulting location for 
the strange SIGSEGV, and that is not even always possible.

However, for your Ubuntu issue, see the mail I'm going to post.
> Rob

-- 
Inform me of my mistakes, so I can keep imitating Homer Simpson's "Doh!".
Paolo Giarrusso, aka Blaisorblade (Skype ID "PaoloGiarrusso", ICQ 215621894)
http://www.user-mode-linux.org/~blaisorblade

		
___________________________________ 
Yahoo! Messenger: chiamate gratuite in tutto il mondo 
http://it.messenger.yahoo.com



-------------------------------------------------------
This SF.Net email is sponsored by:
Power Architecture Resource Center: Free content, downloads, discussions,
and more. http://solutions.newsforge.com/ibmarch.tmpl
_______________________________________________
User-mode-linux-devel mailing list
User-mode-linux-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel