user-mode-linux-user

Re: [uml-user] Website is in need of many small changes and updates?

[Balaco B. <bal...@im...>]

On Thu, Oct 29, 2015, at 16:55, Richard Weinberger wrote:
> On Thu, Oct 29, 2015 at 8:46 PM, Balaco Baco <bal...@im...> wrote:
> >> > > >> > Really!? I wish I had read that somewhere. Well, just retried with
> >> > > >> > another option that is there for me. It is one of the cases I detailed
> >> > > >> > before that end with error.
> >> > > >> >
> >> > > >>
> >> > > >> Linux 2.6.24?! SRSLY?
> >> > >
> >> > > If you want me to help, please use a recent/supported kernel.
> >> > > Ready-to-use root filesystems can be found everywhere.
> >> > > For example: http://fs.devloop.org.uk/
> >> > >
> >> >
> >> > I'm not sure now, but the two Debian root fs I'm using were downloaded
> >> > from the site you point here. Later I'll check their sums, and PS this
> >> > in a next message. Kernels 2.6.* were recent and assumed to be supported
> >> > in most places I could need - or so I assumed.
> >>
> >> > What is your definition of recent and your definition of supported? This
> >> > may be useful for many other users of UML I guess. The fact that the
> >> > kernels offered in the UML website didn't work, and then I tried to
> >> > compile from source should be pointed here. I don't think I have done
> >> > something so weird or uncommon here - mainly because I don't need much
> >> > as long as I have flexibility to execute it.
> >>
> >> Everything that gets -stable updates.
> >
> > Website: UML's, http://user-mode-linux.sourceforge.net/, accessed right
> > now.
> >
> > "Getting started" seemed like a good place for me a few weeks ago (and
> > still does, but...). And I think it will make many users feel and think
> > the same way I did. Except that it gives us wrong directions - but gives
> > bad directions for users that will surely follow them without knowing
> > the wrong details since they're expecting to see something working to
> > get more familiar with UML. "Download THIS ( pointing to
> > http://user-mode-linux.sourceforge.net/linux-2.6.24-rc7.bz2) or THIS
> > (pointing to
> > http://user-mode-linux.sourceforge.net/linux-2.6.24-x86_64.bz2 )". Are
> > these kernel versions familiar to you in the list? They are for me, now
> > I just understood a few more details, and the possible path to solution,
> > to execution without unexpected problems - or so I hope.
> >
> > The thread I started today, quickly skimmed in the above quotes, shows
> > this. The website needs to be fixed. And more than that, needs to be
> > updated more frequently (or so I must guess) or write about how users
> > can be sure their setup is good enough.
> >
> > I downloaded both suggested kernels, following the official (and assumed
> > best, for that) instructions. Both did not work (and still don't). And
> > the one that worked back then is probably needing something I've
> > forgotten in these days or stopped to work today. But that one I
> > compiled from source - and now I need to do it again, from the very
> > start.
> >
> > Everything that gets stable updates... but this should not exclude the
> > UML website, right?
> 
> The website is very old and from the pre-mainline time.
> If you volunteer to update and maintain it it would be wonderful.
> 
> I'm not a web designer nor do I have the time for this.
> 

Really?! I would never bet that it was that old.

I can update it. And I also have a little bit of web design knowledge
and practices that may be eventually useful. On the other hand, I would
need directions and thumbs up to guarantee that the contents are kept
correct (which would be my main objetive when changing texts). I have
not programmed that much kernel code and "related or almost so" things,
although I have a solid C background - and this is something that UML
seems to have a broad contact surface, from the messages I have read
here.

At most a month of medium site changes are good as expectations?
Although most of the time I can give a few hours per week, so that month
should not look too bad.

What would be the process? If only with you directly, I guess we
continue to talk about it between us.


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Re: [uml-user] Website is in need of many small changes and updates?

[Richard W. <ric...@gm...>]

On Thu, Oct 29, 2015 at 8:46 PM, Balaco Baco <bal...@im...> wrote:
>> > > >> > Really!? I wish I had read that somewhere. Well, just retried with
>> > > >> > another option that is there for me. It is one of the cases I detailed
>> > > >> > before that end with error.
>> > > >> >
>> > > >>
>> > > >> Linux 2.6.24?! SRSLY?
>> > >
>> > > If you want me to help, please use a recent/supported kernel.
>> > > Ready-to-use root filesystems can be found everywhere.
>> > > For example: http://fs.devloop.org.uk/
>> > >
>> >
>> > I'm not sure now, but the two Debian root fs I'm using were downloaded
>> > from the site you point here. Later I'll check their sums, and PS this
>> > in a next message. Kernels 2.6.* were recent and assumed to be supported
>> > in most places I could need - or so I assumed.
>>
>> > What is your definition of recent and your definition of supported? This
>> > may be useful for many other users of UML I guess. The fact that the
>> > kernels offered in the UML website didn't work, and then I tried to
>> > compile from source should be pointed here. I don't think I have done
>> > something so weird or uncommon here - mainly because I don't need much
>> > as long as I have flexibility to execute it.
>>
>> Everything that gets -stable updates.
>
> Website: UML's, http://user-mode-linux.sourceforge.net/, accessed right
> now.
>
> "Getting started" seemed like a good place for me a few weeks ago (and
> still does, but...). And I think it will make many users feel and think
> the same way I did. Except that it gives us wrong directions - but gives
> bad directions for users that will surely follow them without knowing
> the wrong details since they're expecting to see something working to
> get more familiar with UML. "Download THIS ( pointing to
> http://user-mode-linux.sourceforge.net/linux-2.6.24-rc7.bz2) or THIS
> (pointing to
> http://user-mode-linux.sourceforge.net/linux-2.6.24-x86_64.bz2 )". Are
> these kernel versions familiar to you in the list? They are for me, now
> I just understood a few more details, and the possible path to solution,
> to execution without unexpected problems - or so I hope.
>
> The thread I started today, quickly skimmed in the above quotes, shows
> this. The website needs to be fixed. And more than that, needs to be
> updated more frequently (or so I must guess) or write about how users
> can be sure their setup is good enough.
>
> I downloaded both suggested kernels, following the official (and assumed
> best, for that) instructions. Both did not work (and still don't). And
> the one that worked back then is probably needing something I've
> forgotten in these days or stopped to work today. But that one I
> compiled from source - and now I need to do it again, from the very
> start.
>
> Everything that gets stable updates... but this should not exclude the
> UML website, right?

The website is very old and from the pre-mainline time.
If you volunteer to update and maintain it it would be wonderful.

I'm not a web designer nor do I have the time for this.

-- 
Thanks,
//richard

[uml-user] Website is in need of many small changes and updates?

[Balaco B. <bal...@im...>]

> > > >> > Really!? I wish I had read that somewhere. Well, just retried with
> > > >> > another option that is there for me. It is one of the cases I detailed
> > > >> > before that end with error.
> > > >> >
> > > >>
> > > >> Linux 2.6.24?! SRSLY?
> > > 
> > > If you want me to help, please use a recent/supported kernel.
> > > Ready-to-use root filesystems can be found everywhere.
> > > For example: http://fs.devloop.org.uk/
> > > 
> > 
> > I'm not sure now, but the two Debian root fs I'm using were downloaded
> > from the site you point here. Later I'll check their sums, and PS this
> > in a next message. Kernels 2.6.* were recent and assumed to be supported
> > in most places I could need - or so I assumed.
> 
> > What is your definition of recent and your definition of supported? This
> > may be useful for many other users of UML I guess. The fact that the
> > kernels offered in the UML website didn't work, and then I tried to
> > compile from source should be pointed here. I don't think I have done
> > something so weird or uncommon here - mainly because I don't need much
> > as long as I have flexibility to execute it.
> 
> Everything that gets -stable updates.

Website: UML's, http://user-mode-linux.sourceforge.net/, accessed right
now.

"Getting started" seemed like a good place for me a few weeks ago (and
still does, but...). And I think it will make many users feel and think
the same way I did. Except that it gives us wrong directions - but gives
bad directions for users that will surely follow them without knowing
the wrong details since they're expecting to see something working to
get more familiar with UML. "Download THIS ( pointing to
http://user-mode-linux.sourceforge.net/linux-2.6.24-rc7.bz2) or THIS
(pointing to
http://user-mode-linux.sourceforge.net/linux-2.6.24-x86_64.bz2 )". Are
these kernel versions familiar to you in the list? They are for me, now
I just understood a few more details, and the possible path to solution,
to execution without unexpected problems - or so I hope.

The thread I started today, quickly skimmed in the above quotes, shows
this. The website needs to be fixed. And more than that, needs to be
updated more frequently (or so I must guess) or write about how users
can be sure their setup is good enough.

I downloaded both suggested kernels, following the official (and assumed
best, for that) instructions. Both did not work (and still don't). And
the one that worked back then is probably needing something I've
forgotten in these days or stopped to work today. But that one I
compiled from source - and now I need to do it again, from the very
start.

Everything that gets stable updates... but this should not exclude the
UML website, right?


-- 
http://www.fastmail.com - The way an email service should be

Re: [uml-user] Possible ways to execute

[Richard W. <ric...@gm...>]

On Thu, Oct 29, 2015 at 4:26 PM, Balaco Baco <bal...@im...> wrote:
> What is your definition of recent and your definition of supported? This
> may be useful for many other users of UML I guess. The fact that the
> kernels offered in the UML website didn't work, and then I tried to
> compile from source should be pointed here. I don't think I have done
> something so weird or uncommon here - mainly because I don't need much
> as long as I have flexibility to execute it.

Everything that gets -stable updates.

-- 
Thanks,
//richard

Re: [uml-user] Possible ways to execute

[Balaco B. <bal...@im...>]

On Thu, Oct 29, 2015, at 11:12, Richard Weinberger wrote:
> On Thu, Oct 29, 2015 at 2:21 PM, Balaco Baco <bal...@im...> wrote:
> >
> > On Thu, Oct 29, 2015, at 10:18, Richard Weinberger wrote:
> >> Am 29.10.2015 um 14:14 schrieb Balaco Baco:
> >> > Really!? I wish I had read that somewhere. Well, just retried with
> >> > another option that is there for me. It is one of the cases I detailed
> >> > before that end with error.
> >> >
> >> > The full execution, right now, is:
> >> >
> >> > ==========================
> >> > $./linux-2.6.24-x86_64 ubda=Debian-Wheezy-AMD64-root_fs mem=128M
> >>
> >> Linux 2.6.24?! SRSLY?
> 
> If you want me to help, please use a recent/supported kernel.
> Ready-to-use root filesystems can be found everywhere.
> For example: http://fs.devloop.org.uk/
> 

I'm not sure now, but the two Debian root fs I'm using were downloaded
from the site you point here. Later I'll check their sums, and PS this
in a next message. Kernels 2.6.* were recent and assumed to be supported
in most places I could need - or so I assumed.

What is your definition of recent and your definition of supported? This
may be useful for many other users of UML I guess. The fact that the
kernels offered in the UML website didn't work, and then I tried to
compile from source should be pointed here. I don't think I have done
something so weird or uncommon here - mainly because I don't need much
as long as I have flexibility to execute it.


-- 
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                          love email again

Re: [uml-user] [PATCH v3] um: net: replace GFP_KERNEL with GFP_ATOMIC when spinlock is held

[Joe P. <jo...@pe...>]

On Thu, 2015-10-29 at 14:46 +0530, Saurabh Sengar wrote:
> replace GFP_KERNEL with GFP_ATOMIC while spinlock is held,
> as code while holding a spinlock should be atomic.
> GFP_KERNEL may sleep and can cause deadlock,
> where as GFP_ATOMIC may fail but certainly avoids deadlock
> 
> Signed-off-by: Saurabh Sengar <sau...@gm...>
> ---
> v3: removed the atomic variable, as per Richard comment

Trivia: You could remove the gfp_mask variables too
	and just use GFP_KERNEL and GFP_ATOMIC directly.

> diff --git a/arch/um/drivers/net_kern.c b/arch/um/drivers/net_kern.c
[]
> @@ -600,20 +600,22 @@ void register_transport(struct transport *new)
>  	void *init;
>  	char *mac = NULL;
>  	int match;
> +	int gfp_mask;
>  
>  	spin_lock(&transports_lock);
>  	BUG_ON(!list_empty(&new->list));
>  	list_add(&new->list, &transports);
>  	spin_unlock(&transports_lock);
>  
> +	gfp_mask = GFP_KERNEL;
>  	list_for_each_safe(ele, next, &eth_cmd_line) {
>  		eth = list_entry(ele, struct eth_init, list);
>  		match = check_transport(new, eth->init, eth->index, &init,
> -					&mac);
> +					&mac, gfp_mask);
>  		if (!match)
>  			continue;
>  		else if (init != NULL) {
> -			eth_configure(eth->index, init, mac, new);
> +			eth_configure(eth->index, init, mac, new, gfp_mask);
>  			kfree(init);
>  		}
>  		list_del(&eth->list);
> @@ -627,14 +629,17 @@ static int eth_setup_common(char *str, int index)
>  	void *init;
>  	char *mac = NULL;
>  	int found = 0;
> +	int gfp_mask;
>  
>  	spin_lock(&transports_lock);
> +	gfp_mask = GFP_ATOMIC;
>  	list_for_each(ele, &transports) {
>  		transport = list_entry(ele, struct transport, list);
> -	        if (!check_transport(transport, str, index, &init, &mac))
> +		if (!check_transport(transport, str, index, &init,
> +							&mac, gfp_mask))
>  			continue;
>  		if (init != NULL) {
> -			eth_configure(index, init, mac, transport);
> +			eth_configure(index, init, mac, transport, gfp_mask);
>  			kfree(init);
>  		}
>  		found = 1;

Re: [uml-user] [PATCH v3] um: net: replace GFP_KERNEL with GFP_ATOMIC when spinlock is held

[Richard W. <ri...@no...>]

Am 29.10.2015 um 15:50 schrieb Joe Perches:
> On Thu, 2015-10-29 at 14:46 +0530, Saurabh Sengar wrote:
>> replace GFP_KERNEL with GFP_ATOMIC while spinlock is held,
>> as code while holding a spinlock should be atomic.
>> GFP_KERNEL may sleep and can cause deadlock,
>> where as GFP_ATOMIC may fail but certainly avoids deadlock
>>
>> Signed-off-by: Saurabh Sengar <sau...@gm...>
>> ---
>> v3: removed the atomic variable, as per Richard comment
> 
> Trivia: You could remove the gfp_mask variables too
> 	and just use GFP_KERNEL and GFP_ATOMIC directly.

Yep.
And "int gfp_mask" does also not make sense, GFP_* is of type
gfp_t.

Thanks,
//richard

Re: [uml-user] Possible ways to execute

[Richard W. <ric...@gm...>]

On Thu, Oct 29, 2015 at 2:21 PM, Balaco Baco <bal...@im...> wrote:
>
> On Thu, Oct 29, 2015, at 10:18, Richard Weinberger wrote:
>> Am 29.10.2015 um 14:14 schrieb Balaco Baco:
>> > Really!? I wish I had read that somewhere. Well, just retried with
>> > another option that is there for me. It is one of the cases I detailed
>> > before that end with error.
>> >
>> > The full execution, right now, is:
>> >
>> > ==========================
>> > $./linux-2.6.24-x86_64 ubda=Debian-Wheezy-AMD64-root_fs mem=128M
>>
>> Linux 2.6.24?! SRSLY?

If you want me to help, please use a recent/supported kernel.
Ready-to-use root filesystems can be found everywhere.
For example: http://fs.devloop.org.uk/

-- 
Thanks,
//richard

Re: [uml-user] Possible ways to execute

[Balaco B. <bal...@im...>]

On Thu, Oct 29, 2015, at 10:21, Balaco Baco wrote:
> 
> On Thu, Oct 29, 2015, at 10:18, Richard Weinberger wrote:
> > Am 29.10.2015 um 14:14 schrieb Balaco Baco:
> > > Really!? I wish I had read that somewhere. Well, just retried with
> > > another option that is there for me. It is one of the cases I detailed
> > > before that end with error.
> > > 
> > > The full execution, right now, is:
> > > 
> > > ==========================
> > > $./linux-2.6.24-x86_64 ubda=Debian-Wheezy-AMD64-root_fs mem=128M
> > 
> > Linux 2.6.24?! SRSLY?
> > 
> 
> What is wrong with that? 
> 

I don't see the problem, but indeed the error lines I sent have, among
other things:

"FATAL: kernel too old"

Can someone please give me kernel version limits and how to find root_fs
files to it? And how to run in (possibly) all kinds of real computers
(if there are limits with this)? I don't see what I am doing wrong, but
there are errors that look strange to me. Strange as "this should not be
happening this way".

If I get a newer kernel would it be fixed? But how did I run these
before, everything normal?




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Re: [uml-user] Possible ways to execute

[Balaco B. <bal...@im...>]

On Thu, Oct 29, 2015, at 10:18, Richard Weinberger wrote:
> Am 29.10.2015 um 14:14 schrieb Balaco Baco:
> > Really!? I wish I had read that somewhere. Well, just retried with
> > another option that is there for me. It is one of the cases I detailed
> > before that end with error.
> > 
> > The full execution, right now, is:
> > 
> > ==========================
> > $./linux-2.6.24-x86_64 ubda=Debian-Wheezy-AMD64-root_fs mem=128M
> 
> Linux 2.6.24?! SRSLY?
> 

What is wrong with that? 

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Re: [uml-user] Possible ways to execute

[Richard W. <ri...@no...>]

Am 29.10.2015 um 14:14 schrieb Balaco Baco:
> Really!? I wish I had read that somewhere. Well, just retried with
> another option that is there for me. It is one of the cases I detailed
> before that end with error.
> 
> The full execution, right now, is:
> 
> ==========================
> $./linux-2.6.24-x86_64 ubda=Debian-Wheezy-AMD64-root_fs mem=128M

Linux 2.6.24?! SRSLY?

Thanks,
//richard

Re: [uml-user] Possible ways to execute

[Balaco B. <bal...@im...>]

Really!? I wish I had read that somewhere. Well, just retried with
another option that is there for me. It is one of the cases I detailed
before that end with error.

The full execution, right now, is:

==========================
$./linux-2.6.24-x86_64 ubda=Debian-Wheezy-AMD64-root_fs mem=128M
Core dump limits :
	soft - 0
	hard - NONE
Checking that ptrace can change system call numbers...OK
Checking syscall emulation patch for ptrace...OK
Checking advanced syscall emulation patch for ptrace...OK
Checking for tmpfs mount on /dev/shm...nothing mounted on /dev/shm
Checking PROT_EXEC mmap in /tmp/...OK
Checking for new_mm and switch_mm support in the host:
	/proc/self/mm ... Failed - 
No such file or directory
Checking for the skas3 patch in the host:
  - /proc/mm...not found: No such file or directory
  - PTRACE_FAULTINFO...not found
  - PTRACE_LDT...not found
UML running in SKAS0 mode
Adding 2719744 bytes to physical memory to account for exec-shield gap
Aborted (core dumped)
$

==========================

Waiting for suggestions. And there are some more details in my first
message - also below in this one,

-- 
  Balaco



On Thu, Oct 29, 2015, at 08:43, Richard Weinberger wrote:
> On Thu, Oct 29, 2015 at 12:28 PM, Balaco Baco <bal...@im...> wrote:
> > A few weeks ago, after more struggling than I expected, I was abble to
> > run UML. I recompiled the linux kernel from source; I did not use the
> > root fs files available in the website, and found a Debian that seems to
> > suit my needs.
> >
> > But yesterday I tried to execute it again, it did not work. The fact
> > that yesterday I tried it through SSH makes a difference?
> >
> > Most of the command lines I had in my Bash history (long enough to have
> > almost everything I did in the previous session with this problem). None
> > of them worked. Most of them just seg fault in the beginning of
> > execution. Error related to root fs (surprise for me!). Just two of the
> > commands I tried did not seg fault immediatelly; but they also give no
> > output, and I had to start another SSH session, at the same time, to be
> > able to kill it (since ctrl+c and any other keyboard shortcuts) would be
> > "processed" my uml. I'm not sure what to do now.
> >
> > This command line I executed right now:
> >
> > ./linux-2.6.24-x86_64 ubda=Debian-Wheezy-x86-root_fs  mem=128M
> 
> You cannot use i386 userspace on a x86_64 kernel.
> 
> > Execute in the folder where the root fs file exists, gives ONLY this
> > output (almost immediatelly). It is through SSH. Is there a problem
> > here? I expected an user/password "screen" or anything similar.
> >
> > The whole output I have for the above command, and I will let it waiting
> > for several minutes, is:
> >
> > ===========================================
> > Core dump limits :
> >         soft - 0
> >         hard - NONE
> > Checking that ptrace can change system call numbers...OK
> > Checking syscall emulation patch for ptrace...OK
> > Checking advanced syscall emulation patch for ptrace...OK
> > Checking for tmpfs mount on /dev/shm...nothing mounted on /dev/shm
> > Checking PROT_EXEC mmap in /tmp/...OK
> > Checking for new_mm and switch_mm support in the host:
> >         /proc/self/mm ... Failed -
> > No such file or directory
> > Checking for the skas3 patch in the host:
> >   - /proc/mm...not found: No such file or directory
> >   - PTRACE_FAULTINFO...not found
> >   - PTRACE_LDT...not found
> > UML running in SKAS0 mode
> > Adding 29876224 bytes to physical memory to account for exec-shield gap
> > Linux version 2.6.24-g91525300-dirty (jd...@am...)
> > (gcc version 4.1.1 20070105 (Red Hat 4.1.1-51)) #1 Mon Jan 28 12:03:41
> > EST 2008
> > Built 1 zonelists in Zone order, mobility grouping on.  Total pages:
> > 39515
> > Kernel command line: ubda=Debian-Wheezy-x86-root_fs mem=128M root=98:0
> > PID hash table entries: 1024 (order: 10, 8192 bytes)
> > Dentry cache hash table entries: 32768 (order: 6, 262144 bytes)
> > Inode-cache hash table entries: 16384 (order: 5, 131072 bytes)
> > Memory: 122164k available
> > Mount-cache hash table entries: 256
> > Checking that host ptys support output SIGIO...Yes
> > Checking that host ptys support SIGIO on close...No, enabling workaround
> > net_namespace: 120 bytes
> > Using 2.6 host AIO
> > NET: Registered protocol family 16
> > NET: Registered protocol family 2
> > Time: itimer clocksource has been installed.
> > IP route cache hash table entries: 2048 (order: 2, 16384 bytes)
> > TCP established hash table entries: 8192 (order: 5, 131072 bytes)
> > TCP bind hash table entries: 8192 (order: 4, 65536 bytes)
> > TCP: Hash tables configured (established 8192 bind 8192)
> > TCP reno registered
> > Checking host MADV_REMOVE support...OK
> > mconsole (version 2) initialized on
> > /home/folder/path/.uml/1DZd7v/mconsole
> > ((! the above line was manually changed for this message; and the
> > working folder is a subfolder in my home folder !))
> > VFS: Disk quotas dquot_6.5.1
> > Dquot-cache hash table entries: 512 (order 0, 4096 bytes)
> > io scheduler noop registered
> > io scheduler anticipatory registered (default)
> > io scheduler deadline registered
> > io scheduler cfq registered
> > TCP cubic registered
> > NET: Registered protocol family 1
> > NET: Registered protocol family 17
> > Initialized stdio console driver
> > Console initialized on /dev/tty0
> > console [tty0] enabled
> > Initializing software serial port version 1
> > console [mc-1] enabled
> >  ubda: unknown partition table
> > kjournald starting.  Commit interval 5 seconds
> > EXT3-fs: mounted filesystem with ordered data mode.
> > VFS: Mounted root (ext3 filesystem) readonly.
> > request_module: runaway loop modprobe binfmt-464c
> > request_module: runaway loop modprobe binfmt-464c
> > request_module: runaway loop modprobe binfmt-464c
> > request_module: runaway loop modprobe binfmt-464c
> > request_module: runaway loop modprobe binfmt-464c
> >
> > ===========================================
> >
> > What do you suggest to try?
> >
> > --
> >   Balaco
> >
> >
> > --
> > http://www.fastmail.com - A fast, anti-spam email service.
> >
> >
> > ------------------------------------------------------------------------------
> > _______________________________________________
> > User-mode-linux-user mailing list
> > Use...@li...
> > https://lists.sourceforge.net/lists/listinfo/user-mode-linux-user
> 
> 
> 
> -- 
> Thanks,
> //richard

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Re: [uml-user] Possible ways to execute

[Richard W. <ric...@gm...>]

On Thu, Oct 29, 2015 at 12:28 PM, Balaco Baco <bal...@im...> wrote:
> A few weeks ago, after more struggling than I expected, I was abble to
> run UML. I recompiled the linux kernel from source; I did not use the
> root fs files available in the website, and found a Debian that seems to
> suit my needs.
>
> But yesterday I tried to execute it again, it did not work. The fact
> that yesterday I tried it through SSH makes a difference?
>
> Most of the command lines I had in my Bash history (long enough to have
> almost everything I did in the previous session with this problem). None
> of them worked. Most of them just seg fault in the beginning of
> execution. Error related to root fs (surprise for me!). Just two of the
> commands I tried did not seg fault immediatelly; but they also give no
> output, and I had to start another SSH session, at the same time, to be
> able to kill it (since ctrl+c and any other keyboard shortcuts) would be
> "processed" my uml. I'm not sure what to do now.
>
> This command line I executed right now:
>
> ./linux-2.6.24-x86_64 ubda=Debian-Wheezy-x86-root_fs  mem=128M

You cannot use i386 userspace on a x86_64 kernel.

> Execute in the folder where the root fs file exists, gives ONLY this
> output (almost immediatelly). It is through SSH. Is there a problem
> here? I expected an user/password "screen" or anything similar.
>
> The whole output I have for the above command, and I will let it waiting
> for several minutes, is:
>
> ===========================================
> Core dump limits :
>         soft - 0
>         hard - NONE
> Checking that ptrace can change system call numbers...OK
> Checking syscall emulation patch for ptrace...OK
> Checking advanced syscall emulation patch for ptrace...OK
> Checking for tmpfs mount on /dev/shm...nothing mounted on /dev/shm
> Checking PROT_EXEC mmap in /tmp/...OK
> Checking for new_mm and switch_mm support in the host:
>         /proc/self/mm ... Failed -
> No such file or directory
> Checking for the skas3 patch in the host:
>   - /proc/mm...not found: No such file or directory
>   - PTRACE_FAULTINFO...not found
>   - PTRACE_LDT...not found
> UML running in SKAS0 mode
> Adding 29876224 bytes to physical memory to account for exec-shield gap
> Linux version 2.6.24-g91525300-dirty (jd...@am...)
> (gcc version 4.1.1 20070105 (Red Hat 4.1.1-51)) #1 Mon Jan 28 12:03:41
> EST 2008
> Built 1 zonelists in Zone order, mobility grouping on.  Total pages:
> 39515
> Kernel command line: ubda=Debian-Wheezy-x86-root_fs mem=128M root=98:0
> PID hash table entries: 1024 (order: 10, 8192 bytes)
> Dentry cache hash table entries: 32768 (order: 6, 262144 bytes)
> Inode-cache hash table entries: 16384 (order: 5, 131072 bytes)
> Memory: 122164k available
> Mount-cache hash table entries: 256
> Checking that host ptys support output SIGIO...Yes
> Checking that host ptys support SIGIO on close...No, enabling workaround
> net_namespace: 120 bytes
> Using 2.6 host AIO
> NET: Registered protocol family 16
> NET: Registered protocol family 2
> Time: itimer clocksource has been installed.
> IP route cache hash table entries: 2048 (order: 2, 16384 bytes)
> TCP established hash table entries: 8192 (order: 5, 131072 bytes)
> TCP bind hash table entries: 8192 (order: 4, 65536 bytes)
> TCP: Hash tables configured (established 8192 bind 8192)
> TCP reno registered
> Checking host MADV_REMOVE support...OK
> mconsole (version 2) initialized on
> /home/folder/path/.uml/1DZd7v/mconsole
> ((! the above line was manually changed for this message; and the
> working folder is a subfolder in my home folder !))
> VFS: Disk quotas dquot_6.5.1
> Dquot-cache hash table entries: 512 (order 0, 4096 bytes)
> io scheduler noop registered
> io scheduler anticipatory registered (default)
> io scheduler deadline registered
> io scheduler cfq registered
> TCP cubic registered
> NET: Registered protocol family 1
> NET: Registered protocol family 17
> Initialized stdio console driver
> Console initialized on /dev/tty0
> console [tty0] enabled
> Initializing software serial port version 1
> console [mc-1] enabled
>  ubda: unknown partition table
> kjournald starting.  Commit interval 5 seconds
> EXT3-fs: mounted filesystem with ordered data mode.
> VFS: Mounted root (ext3 filesystem) readonly.
> request_module: runaway loop modprobe binfmt-464c
> request_module: runaway loop modprobe binfmt-464c
> request_module: runaway loop modprobe binfmt-464c
> request_module: runaway loop modprobe binfmt-464c
> request_module: runaway loop modprobe binfmt-464c
>
> ===========================================
>
> What do you suggest to try?
>
> --
>   Balaco
>
>
> --
> http://www.fastmail.com - A fast, anti-spam email service.
>
>
> ------------------------------------------------------------------------------
> _______________________________________________
> User-mode-linux-user mailing list
> Use...@li...
> https://lists.sourceforge.net/lists/listinfo/user-mode-linux-user



-- 
Thanks,
//richard

[uml-user] Possible ways to execute

[Balaco B. <bal...@im...>]

A few weeks ago, after more struggling than I expected, I was abble to
run UML. I recompiled the linux kernel from source; I did not use the
root fs files available in the website, and found a Debian that seems to
suit my needs.

But yesterday I tried to execute it again, it did not work. The fact
that yesterday I tried it through SSH makes a difference?

Most of the command lines I had in my Bash history (long enough to have
almost everything I did in the previous session with this problem). None
of them worked. Most of them just seg fault in the beginning of
execution. Error related to root fs (surprise for me!). Just two of the
commands I tried did not seg fault immediatelly; but they also give no
output, and I had to start another SSH session, at the same time, to be
able to kill it (since ctrl+c and any other keyboard shortcuts) would be
"processed" my uml. I'm not sure what to do now.

This command line I executed right now:

./linux-2.6.24-x86_64 ubda=Debian-Wheezy-x86-root_fs  mem=128M 

Execute in the folder where the root fs file exists, gives ONLY this
output (almost immediatelly). It is through SSH. Is there a problem
here? I expected an user/password "screen" or anything similar.

The whole output I have for the above command, and I will let it waiting
for several minutes, is:

===========================================
Core dump limits :
	soft - 0
	hard - NONE
Checking that ptrace can change system call numbers...OK
Checking syscall emulation patch for ptrace...OK
Checking advanced syscall emulation patch for ptrace...OK
Checking for tmpfs mount on /dev/shm...nothing mounted on /dev/shm
Checking PROT_EXEC mmap in /tmp/...OK
Checking for new_mm and switch_mm support in the host:
	/proc/self/mm ... Failed - 
No such file or directory
Checking for the skas3 patch in the host:
  - /proc/mm...not found: No such file or directory
  - PTRACE_FAULTINFO...not found
  - PTRACE_LDT...not found
UML running in SKAS0 mode
Adding 29876224 bytes to physical memory to account for exec-shield gap
Linux version 2.6.24-g91525300-dirty (jd...@am...)
(gcc version 4.1.1 20070105 (Red Hat 4.1.1-51)) #1 Mon Jan 28 12:03:41
EST 2008
Built 1 zonelists in Zone order, mobility grouping on.  Total pages:
39515
Kernel command line: ubda=Debian-Wheezy-x86-root_fs mem=128M root=98:0
PID hash table entries: 1024 (order: 10, 8192 bytes)
Dentry cache hash table entries: 32768 (order: 6, 262144 bytes)
Inode-cache hash table entries: 16384 (order: 5, 131072 bytes)
Memory: 122164k available
Mount-cache hash table entries: 256
Checking that host ptys support output SIGIO...Yes
Checking that host ptys support SIGIO on close...No, enabling workaround
net_namespace: 120 bytes
Using 2.6 host AIO
NET: Registered protocol family 16
NET: Registered protocol family 2
Time: itimer clocksource has been installed.
IP route cache hash table entries: 2048 (order: 2, 16384 bytes)
TCP established hash table entries: 8192 (order: 5, 131072 bytes)
TCP bind hash table entries: 8192 (order: 4, 65536 bytes)
TCP: Hash tables configured (established 8192 bind 8192)
TCP reno registered
Checking host MADV_REMOVE support...OK
mconsole (version 2) initialized on
/home/folder/path/.uml/1DZd7v/mconsole
((! the above line was manually changed for this message; and the
working folder is a subfolder in my home folder !))
VFS: Disk quotas dquot_6.5.1
Dquot-cache hash table entries: 512 (order 0, 4096 bytes)
io scheduler noop registered
io scheduler anticipatory registered (default)
io scheduler deadline registered
io scheduler cfq registered
TCP cubic registered
NET: Registered protocol family 1
NET: Registered protocol family 17
Initialized stdio console driver
Console initialized on /dev/tty0
console [tty0] enabled
Initializing software serial port version 1
console [mc-1] enabled
 ubda: unknown partition table
kjournald starting.  Commit interval 5 seconds
EXT3-fs: mounted filesystem with ordered data mode.
VFS: Mounted root (ext3 filesystem) readonly.
request_module: runaway loop modprobe binfmt-464c
request_module: runaway loop modprobe binfmt-464c
request_module: runaway loop modprobe binfmt-464c
request_module: runaway loop modprobe binfmt-464c
request_module: runaway loop modprobe binfmt-464c

===========================================

What do you suggest to try?

-- 
  Balaco


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Re: [uml-user] [PATCH v2] um: net: replace GFP_KERNEL with GFP_ATOMIC when spinlock is held

[Richard W. <ri...@no...>]

Am 29.10.2015 um 08:27 schrieb Saurabh Sengar:
> replace GFP_KERNEL with GFP_ATOMIC while spinlock is held,
> as code while holding a spinlock should be atomic.
> GFP_KERNEL may sleep and can cause deadlock,
> where as GFP_ATOMIC may fail but certainly avoids deadlock

As UML does not support SMP nor PREEMPT this is a non issue,
spinlocks are a NOP.
But for the sake of completeness you are right, the code needs
fixing.

> Signed-off-by: Saurabh Sengar <sau...@gm...>
> ---
> v2: correcting the subject
> 
>  arch/um/drivers/net_kern.c | 31 +++++++++++++++++++++++--------
>  1 file changed, 23 insertions(+), 8 deletions(-)
> 
> diff --git a/arch/um/drivers/net_kern.c b/arch/um/drivers/net_kern.c
> index f70dd54..7d4b709 100644
> --- a/arch/um/drivers/net_kern.c
> +++ b/arch/um/drivers/net_kern.c
> @@ -388,16 +388,22 @@ static const struct net_device_ops uml_netdev_ops = {
>  static int driver_registered;
>  
>  static void eth_configure(int n, void *init, char *mac,
> -			  struct transport *transport)
> +			  struct transport *transport, bool atomic)

Why do you need this atomic variable? Can't you just pass gfp_mask around?

Thanks,
//richard

Re: [uml-user] Any reason for a kernel thread not run after calling schedule()?

[Richard W. <ric...@gm...>]

On Wed, Oct 28, 2015 at 5:36 PM, Ricardo Nunes
<ric...@gm...> wrote:
> Hi,
>
> I'm making a UML driver to adapt a real driver to UML and hardware
> emulation.
>
> In this case I have a kernel thread trying to read a register, which is now
> done through a netlink channel to a userspace application (asynchronous
> response) but inside a synchronous function (the function that I'm
> implementing returns the register value). The first attempt was done doing:
>
> Kernel thread
>
> sleeping_task = current;
> set_current_state(TASK_INTERRUPTIBLE);
> schedule();
>
> Netlink new message callback
>
> wake_up_process(sleeping_task);
>
> But the kernel thread never runs again, unless I call schedule() in netlink
> callback function after wake_up_process, which will make that callback being
> blocked. I also tried using wait_queue but after the same result I saw the
> functions and realised that they also use schedule for putting the process
> to sleep.
>
> This worked in a "real" linux module (not with netlink callback, but between
> 2 kernel threads), I don't understand why shouldn't in UML. Any reason you
> might remember?

Can you please share your code?

-- 
Thanks,
//richard

[uml-user] Any reason for a kernel thread not run after calling schedule()?

[Ricardo N. <ric...@gm...>]

Hi,

I'm making a UML driver to adapt a real driver to UML and hardware
emulation.

In this case I have a kernel thread trying to read a register, which is now
done through a netlink channel to a userspace application (asynchronous
response) but inside a synchronous function (the function that I'm
implementing returns the register value). The first attempt was done doing:

*Kernel thread*

sleeping_task = current;
set_current_state(TASK_INTERRUPTIBLE);
schedule();

*Netlink new message callback*

wake_up_process(sleeping_task);

But the kernel thread never runs again, unless I call schedule() in
netlink callback function after wake_up_process, which will make that
callback being blocked. I also tried using wait_queue but after the
same result I saw the functions and realised that they also use
schedule for putting the process to sleep.

This worked in a "real" linux module (not with netlink callback, but
between 2 kernel threads), I don't understand why shouldn't in UML.
Any reason you might remember?

I'm using 4.2.1 Kernel with a Debian Jessie distro.

Re: [uml-user] IRQ support?

[Richard W. <ric...@gm...>]

Hi!

CC'ing -devel list.

On Thu, Oct 22, 2015 at 1:29 PM, Ricardo Nunes
<ric...@gm...> wrote:
> I'm trying to use a real hardware driver inside UML and I,ve come to the IRQ
> suppor part.

How do you map the hardware into UML?

> Right now it's failing on request_irq call, so my question is if there is
> any manual on how to support this method calls in UML or if it's supposed to
> work as it is.
>
> I need to register IRQs and raise them. After a few searches I saw SIGIO
> module and everything, but it didn't help enough.

UML is using SIGIO for interrupts.

> What's the best way to support this?

Well, it depends how you map the hardware.
Maybe you can use vfio.

-- 
Thanks,
//richard

Re: [uml-user] IRQ support?

[Ricardo N. <ric...@gm...>]

After some digging in the kernel I've found out that it's failing inside
request_threaded_irq
<http://lxr.free-electrons.com/source/kernel/irq/manage.c#L1527> function,
specifically on the irq_to_desc.

I'm studying what it might be, do you think it's UML related?

2015-10-22 12:29 GMT+01:00 Ricardo Nunes <ric...@gm...>:

> I'm trying to use a real hardware driver inside UML and I,ve come to the
> IRQ suppor part.
>
> Right now it's failing on request_irq call, so my question is if there is
> any manual on how to support this method calls in UML or if it's supposed
> to work as it is.
>
> I need to register IRQs and raise them. After a few searches I saw SIGIO
> module and everything, but it didn't help enough.
>
> What's the best way to support this?
>
> Thanks
>

[uml-user] IRQ support?

[Ricardo N. <ric...@gm...>]

I'm trying to use a real hardware driver inside UML and I,ve come to the
IRQ suppor part.

Right now it's failing on request_irq call, so my question is if there is
any manual on how to support this method calls in UML or if it's supposed
to work as it is.

I need to register IRQs and raise them. After a few searches I saw SIGIO
module and everything, but it didn't help enough.

What's the best way to support this?

Thanks

Re: [uml-user] UML <-> host communication

[Richard W. <ric...@gm...>]

On Mon, Oct 12, 2015 at 6:21 PM, Ricardo Nunes
<ric...@gm...> wrote:
> Right now I'm just finding for a way to make it work, so slow communications
> will also be acceptable for now. This is for device emulation, so a lot of
> memory reads and writes. Better slower then non existent.
>
> If I use a tuntap, a socket or something like that, what API can I use to
> communicate straight from the kernel to the host?
>
> I just tried to implement netpoll sockets, but it doesn't seem to be
> supported inside UML.

What is missing?

Anyway, you can create a debugfs file within UML which opens a fd on
the host side and wrapps
this fd into a file visible to UML guest processes.

-- 
Thanks,
//richard

Re: [uml-user] UML <-> host communication

[Ricardo N. <ric...@gm...>]

Right now I'm just finding for a way to make it work, so slow
communications will also be acceptable for now. This is for device
emulation, so a lot of memory reads and writes. Better slower then non
existent.

If I use a tuntap, a socket or something like that, what API can I use to
communicate straight from the kernel to the host?

I just tried to implement netpoll sockets
<http://stackoverflow.com/a/12175937/538339>, but it doesn't seem to be
supported inside UML.

2015-10-12 16:50 GMT+01:00 Balaco Baco <bal...@im...>:

> Interesting idea! :)
>
> But why not using "real" network connections? If you keep a connection
> open, you will have no "big" overhead besides openning it the first time
> (or reopenning, if eventually needed). You will be able to choose the
> format of each message contents, as desired. And the communication can
> be redirected to whatever you need, both in the UML or the host system.
>
> You wrote about low latency, but gave no estimatives you expect. What
> would be it? And what have you discarded using with this constraint?
>
> --
>   Balaco
>
>
>
> On Mon, Oct 12, 2015, at 11:46, Ricardo Nunes wrote:
> > Hi. I'm trying to create a 2 way communication channel between a kernel
> > driver in UML with a process at the host.
> >
> > What's the best way to do it? I started by trying to create a pipe ath
> > the
> > host, share in hostfs but I can't get any communication (write on pipe in
> > UML, nothing appears in host).
> >
> > Plus, I'm using os_open_file kind of functions (shared/os.h) but it
> > always
> > return me error -2 (bad file path). I thought that it could be because
> > the
> > kernel module was loaded before the hostfs is mounted but the same error
> > happens if I insmod it after boot.
> >
> > What are the alternatives here? I wanted a low latency type of
> > communication, minimum overhead since it will be a lot of communications
> > os
> > 5-10 bytes each time.
> >
> > Thanks
> >
> ------------------------------------------------------------------------------
> > _______________________________________________
> > User-mode-linux-user mailing list
> > Use...@li...
> > https://lists.sourceforge.net/lists/listinfo/user-mode-linux-user
>
> --
> http://www.fastmail.com - Accessible with your email software
>                           or over the web
>
>
>
> ------------------------------------------------------------------------------
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>

Re: [uml-user] UML <-> host communication

[Balaco B. <bal...@im...>]

Interesting idea! :)

But why not using "real" network connections? If you keep a connection
open, you will have no "big" overhead besides openning it the first time
(or reopenning, if eventually needed). You will be able to choose the
format of each message contents, as desired. And the communication can
be redirected to whatever you need, both in the UML or the host system.

You wrote about low latency, but gave no estimatives you expect. What
would be it? And what have you discarded using with this constraint?

-- 
  Balaco



On Mon, Oct 12, 2015, at 11:46, Ricardo Nunes wrote:
> Hi. I'm trying to create a 2 way communication channel between a kernel
> driver in UML with a process at the host.
> 
> What's the best way to do it? I started by trying to create a pipe ath
> the
> host, share in hostfs but I can't get any communication (write on pipe in
> UML, nothing appears in host).
> 
> Plus, I'm using os_open_file kind of functions (shared/os.h) but it
> always
> return me error -2 (bad file path). I thought that it could be because
> the
> kernel module was loaded before the hostfs is mounted but the same error
> happens if I insmod it after boot.
> 
> What are the alternatives here? I wanted a low latency type of
> communication, minimum overhead since it will be a lot of communications
> os
> 5-10 bytes each time.
> 
> Thanks
> ------------------------------------------------------------------------------
> _______________________________________________
> User-mode-linux-user mailing list
> Use...@li...
> https://lists.sourceforge.net/lists/listinfo/user-mode-linux-user

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                          or over the web

[uml-user] UML <-> host communication

[Ricardo N. <ric...@gm...>]

Hi. I'm trying to create a 2 way communication channel between a kernel
driver in UML with a process at the host.

What's the best way to do it? I started by trying to create a pipe ath the
host, share in hostfs but I can't get any communication (write on pipe in
UML, nothing appears in host).

Plus, I'm using os_open_file kind of functions (shared/os.h) but it always
return me error -2 (bad file path). I thought that it could be because the
kernel module was loaded before the hostfs is mounted but the same error
happens if I insmod it after boot.

What are the alternatives here? I wanted a low latency type of
communication, minimum overhead since it will be a lot of communications os
5-10 bytes each time.

Thanks

Re: [uml-user] Creating Wheezy filesystem from scratch

[Richard W. <ric...@gm...>]

On Fri, Oct 9, 2015 at 5:11 PM, Ricardo Nunes
<ric...@gm...> wrote:
> I'm trying to create a Debian Wheezy filesystem to use in User Mode Linux.
> right now I'm following this tutorial. The commands after # Remove the other
> terminal events don't work here and I can't find the equivalent operations
> in Wheezy.
>
> When I try to boot all of the system gets frozen and ends up with this (full
> log here):
>
> INIT: Entering runlevel: 2
>
>     [[36minfo[39;49m] Using makefile-style concurrent boot in runlevel 2.
>     [   12.690000] Virtual console 5 assigned device '/dev/pts/12'
>     [   12.690000] Virtual console 6 assigned device '/dev/pts/19'
>     [   12.690000] Virtual console 4 assigned device '/dev/pts/20'
>     [   12.690000] Virtual console 3 assigned device '/dev/pts/26'
>     [   12.690000] Virtual console 2 assigned device '/dev/pts/27'
>     [   12.690000] Virtual console 1 assigned device '/dev/pts/28'
>
> I would use a already prepared filesystem, or even rootstrap, but both of
> them forces me to have internet inside the UML machine and, for security
> reasons in this environment, I cannot create bridges to my own network.
>
> Do you know how can I pass this until I get a login message?

Assign a getty to /dev/tty0.
Your debian spawned 6 gettys on serial devices, try "screen /dev/pts/28".

-- 
Thanks,
//richard