Re: simulating wireless device (if_alloc panic, VirtualBox, VIMAGE)

2011-02-03 Thread Monthadar Al Jaberi
On Wed, Feb 2, 2011 at 8:06 PM, Julian Elischer jul...@freebsd.org wrote:
 On 2/2/11 10:05 AM, Monthadar Al Jaberi wrote:

 I just tried something that seems to work, but please dont hit me ^^;;;

 in wtap_ioctl I assigned curthread-td_vnet myself to point to a VNET
 (saved it when the module first loaded) (I have not created any jails
 yet)... and it works... I didnt put any CURVNET macros...

 td-td_vnet is exactly what the CURVNET_SET macro sets.
 You should use the Macros because we may change the place where we store it.

 The vnet for the current thread is picked up from several places depending
 on the context,
 and it is cleared again when it is not needed.  the V_xxx usages in the code
 end up being
 in effect expanded to curthread-td_vnet.xxx, where each 'xxx' is sort of
 like an element in a structure
 but not quite.

 Now, theoretically we could just leave it set all the time but then it would
 be nearly impossible
 to find places where we should have changed it, but forgot and just got the
 existing one.

 if you want to find the correct place to go, then look at the vnet of the
 calling process
 which should be in the process cred. or just use vnet0.

Can I check it from user space?


 I don't understand why you saw a CRED_TO_VNET of 0
 I was under the impression that every process/thread in the system would be
 on vnet0
 in a vimage kernel.

This is how my printf looks like:
struct thread *td = curthread;
struct vnet *v = TD_TO_VNET(td);
struct ucred *cred = CRED_TO_VNET(td-ucred);
struct vnet *td_vnet = td-td_vnet;
printf(td=%p, td-td_vnet=%p, td-td_ucred=%p, TD_TO_VNET=%p,
CRED_TO_VNET=%p\n, td, td_vnet, td-td_ucred, v, cred);

I made a fast search in /usr/src for td_vnet and found it was
assigned only in
int fork1(td, flags, pages, procp):
#ifdef VIMAGE
td2-td_vnet = NULL;
td2-td_vnet_lpush = NULL;
#endif

Maybe something wrong with how I declare my wtap_ioctl:

static struct cdevsw wtap_cdevsw = {
.d_version =D_VERSION,
.d_flags =  0,
.d_ioctl =  wtap_ioctl,
.d_name =   wtapctl,
};
...
make_dev(wtap_cdevsw,0,UID_ROOT,GID_WHEEL,0600,(const char *)wtapctl);


 your stored vnet idea is ok as well, but may go strange if you load the
 driver from a vnet jail
 and then remove the jail.

Ok, will document it in the code for now





 my assumption is that if ath drivers dont use VNET I shouldnt :P

 What is wrong with this hack?

 br,

 P.S. I have printed porting to vnet text to have it always at hand,
 but its a bit hard for me... doing my best.

 On Wed, Feb 2, 2011 at 6:30 PM, Julian Elischerjul...@freebsd.org
  wrote:

 On 2/2/11 9:12 AM, Bjoern A. Zeeb wrote:

 On Wed, 2 Feb 2011, Monthadar Al Jaberi wrote:

 Hi,

 Thanx makes more sense, but I have noticed something weired if you can
 shade some light on.

 I added printfs one when the module is first loaded (static int
 event_handler(module_t module, int event, void *arg)):
 curthread=0xc3f95870
 curthread-td_vnet=0xc3170e00
 curthread-td_ucred=0xc3185d00
 TD_TO_VNET=0
 CRED_TO_VNET=0

 Try to load it from laoder on boot; I think that should work as we are
 setting the curvent for the kernel startup.

 The problem you are seeing is a bug in the current implementation that
 you cannot add any physical network interface after the kernel started.
 This applies to cardbus/usb/... as well as any kind of ethernet
 interface, so a kldload igb should yield it as well.

 The fix for that is easy and hard at the same time:
 A) either touch all drivers
 B) or touch all cloned interfaces and change 3 common lines.
   or try to make cloners aware of vimages.

 Solution B) is sitting in perforce with the entire stuff that it depends
 on and was started with CH=179022,179255 but not limited to that if you
 want to have a peek.

 What you certainly can do locally to your driver for now is to make a
 change like this:

 +#ifdef VIMAGE
 +       CURVNET_SET(vnet0);
 +#endif
        ifp = if_alloc(IFT_ETHER);
 +#ifdef VIMAGE
 +       CURVNET_RESTORE();
 +#endif

 you don't really need  the #ifdef except for readability as CURVNET_XXX
 ar
 enot defined for !vnet

 It's the type A) kind of change from above that will break eventually
 in the future.

 /bz









-- 
//Monthadar Al Jaberi
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Re: simulating wireless device (if_alloc panic, VirtualBox, VIMAGE)

2011-02-03 Thread Bjoern A. Zeeb

On Thu, 3 Feb 2011, Monthadar Al Jaberi wrote:


On Thu, Feb 3, 2011 at 12:18 PM, Bjoern A. Zeeb
bzeeb-li...@lists.zabbadoz.net wrote:

On Thu, 3 Feb 2011, Monthadar Al Jaberi wrote:


On Thu, Feb 3, 2011 at 11:59 AM, Bjoern A. Zeeb
bzeeb-li...@lists.zabbadoz.net wrote:


On Thu, 3 Feb 2011, Monthadar Al Jaberi wrote:


I don't understand why you saw a CRED_TO_VNET of 0
I was under the impression that every process/thread in the system
would
be
on vnet0
in a vimage kernel.


This is how my printf looks like:
struct thread *td = curthread;
struct vnet *v = TD_TO_VNET(td);
struct ucred *cred = CRED_TO_VNET(td-ucred);
struct vnet *td_vnet = td-td_vnet;


here's your problem:

strcut vnet *vnet = cred-cr_prison-pr_vnet;


When I add CURVNET_SET(CRED_TO_VNET(curthread-td_ucred)); I get a panic
too...
But your suggestion works if I do like this:
curthread-td_vnet = curthread-td_ucred-cr_prison-pr_vnet;

CRED_TO_VNET(curthread-td_ucred) returns NULL


I wonder how you are building your module and if VIMAGE is properly
defined.  If it's not that would explain a lot of things.


I have put options VIMAGE, rebuild both world and kernel.

I can create jails with vnet options...

I build my module with the standard Makefile for modules:
...
KMOD    =  wtap
...
SRCS    =  if_wtap_module.c if_wtap.c if_medium.c hal.c

.include bsd.kmod.mk


Right but are you building your module along with the kernel or
outside the tree?  In the latter case you may want to add soemthing
like

SRCS+=          opt_global.h

.if defined(KERNBUILDDIR)
MKDEP=          -include ${KERNBUILDDIR}/opt_global.h
.else
CFLAGS+=        -include opt_global.h
MKDEP=          -include opt_global.h

opt_global.h:
       echo #define VIMAGE 1  ${.TARGET}
.endif

and/or point KERNBUILDDIR to where you built your kernels.


Thanks it works now..



One thing you should be aware of is that if you will compile without
KERNBUILDDIR set, your module will not work on a non-VIMAGE kernel.

Unfortuantely we can only have defaults for one or the other in the
case.  Worst you may want to only do the echo if there was a command
line option like -DVIMAGE or the like.  Note, setting it to 0 will not
do the trick as it would still be defined.

/bz

--
Bjoern A. Zeeb You have to have visions!
ks Going to jail sucks -- bz All my daemons like it!
  http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/jails.html___
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Re: simulating wireless device (if_alloc panic, VirtualBox, VIMAGE)

2011-02-03 Thread Adrian Penisoara
Hi,

  Since we're going to see VIMAGE (partly) committed into HEAD anytime
now, perhaps it would be a good time to make available some clear
developer documentation on how to cope with VIMAGE in the kernel (at
kernel build time or building a module separately). 3rd party driver
vendors will be most interested in this.

PS: it would be very welcoming for such mechanisms to be elegant in
their usage ;)...

Thank you,
Adrian.

On Thu, Feb 3, 2011 at 9:35 PM, Bjoern A. Zeeb
bzeeb-li...@lists.zabbadoz.net wrote:
 On Thu, 3 Feb 2011, Monthadar Al Jaberi wrote:

 On Thu, Feb 3, 2011 at 12:18 PM, Bjoern A. Zeeb
 bzeeb-li...@lists.zabbadoz.net wrote:

 On Thu, 3 Feb 2011, Monthadar Al Jaberi wrote:

 On Thu, Feb 3, 2011 at 11:59 AM, Bjoern A. Zeeb
 bzeeb-li...@lists.zabbadoz.net wrote:

 On Thu, 3 Feb 2011, Monthadar Al Jaberi wrote:

 I don't understand why you saw a CRED_TO_VNET of 0
 I was under the impression that every process/thread in the system
 would
 be
 on vnet0
 in a vimage kernel.

 This is how my printf looks like:
 struct thread *td = curthread;
 struct vnet *v = TD_TO_VNET(td);
 struct ucred *cred = CRED_TO_VNET(td-ucred);
 struct vnet *td_vnet = td-td_vnet;

 here's your problem:

 strcut vnet *vnet = cred-cr_prison-pr_vnet;

 When I add CURVNET_SET(CRED_TO_VNET(curthread-td_ucred)); I get a
 panic
 too...
 But your suggestion works if I do like this:
 curthread-td_vnet = curthread-td_ucred-cr_prison-pr_vnet;

 CRED_TO_VNET(curthread-td_ucred) returns NULL

 I wonder how you are building your module and if VIMAGE is properly
 defined.  If it's not that would explain a lot of things.

 I have put options VIMAGE, rebuild both world and kernel.

 I can create jails with vnet options...

 I build my module with the standard Makefile for modules:
 ...
 KMOD    =  wtap
 ...
 SRCS    =  if_wtap_module.c if_wtap.c if_medium.c hal.c

 .include bsd.kmod.mk

 Right but are you building your module along with the kernel or
 outside the tree?  In the latter case you may want to add soemthing
 like

 SRCS+=          opt_global.h

 .if defined(KERNBUILDDIR)
 MKDEP=          -include ${KERNBUILDDIR}/opt_global.h
 .else
 CFLAGS+=        -include opt_global.h
 MKDEP=          -include opt_global.h

 opt_global.h:
        echo #define VIMAGE 1  ${.TARGET}
 .endif

 and/or point KERNBUILDDIR to where you built your kernels.

 Thanks it works now..


 One thing you should be aware of is that if you will compile without
 KERNBUILDDIR set, your module will not work on a non-VIMAGE kernel.

 Unfortuantely we can only have defaults for one or the other in the
 case.  Worst you may want to only do the echo if there was a command
 line option like -DVIMAGE or the like.  Note, setting it to 0 will not
 do the trick as it would still be defined.

 /bz

 --
 Bjoern A. Zeeb                                 You have to have visions!
        ks Going to jail sucks -- bz All my daemons like it!
  http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/jails.html
 ___
 freebsd-virtualization@freebsd.org mailing list
 http://lists.freebsd.org/mailman/listinfo/freebsd-virtualization
 To unsubscribe, send any mail to
 freebsd-virtualization-unsubscr...@freebsd.org


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Re: simulating wireless device (if_alloc panic, VirtualBox, VIMAGE)

2011-02-02 Thread Julian Elischer

On 2/2/11 7:06 AM, Monthadar Al Jaberi wrote:

Thanx makes more sense, but I have noticed something weired if you can
shade some light on.

I added printfs one when the module is first loaded (static int
event_handler(module_t module, int event, void *arg)):
curthread=0xc3f95870
curthread-td_vnet=0xc3170e00
curthread-td_ucred=0xc3185d00
TD_TO_VNET=0
CRED_TO_VNET=0


And same printf in wtap_ioctl which is called from a user space
program (I am root):
curthread=0xc3f952d0
curthread-td_vnet=0
curthread-td_ucred=0xc3185d00
TD_TO_VNET=0
CRED_TO_VNET=0


In both cases TD_TO_VNET/CRED_TO_VNET return NULL... shouldn't they
return a pointer same as curthread-td_vnet? Another thing is that in
wtap_ioctl curthread-td_vnet is NULL


that depends on where in your code you did the print..

have you read this file?

http://p4db.freebsd.org/fileViewer.cgi?FSPC=//depot/projects/vimage/porting_to_vimage.txtREV=18
use the 'download' button to get a more readable version.

it goes into some of the details of this. especially the 
initialization or vimage modules.



I still get a panic...

br,

On Tue, Feb 1, 2011 at 8:37 PM, Julian Elischerjul...@freebsd.org  wrote:

ok here's how it works..

any place you access a V_xxx variable you need to have the current vnet set.
so somewhere in your code path to get to that point you have to have done
CURVNET_SET() and after you have finised on the way out you should do
CURVNET_RESTORE().

you can get the vnet from several places:

1/ as shown below, you can get it from any thread's cred if teh running
thread is part of a
process in the jail in question.
2/ if you have an ifp pointer, you can use ifp-vnet  .   I think that's
right, it's been a while...
3/ I believe though I may be wrong  (I may be thinking of multi FIBS)
that it maybe in the socket structure too but don't trust me on that one..
check it.

if, like in a timer thread you have access to NONE of those, you have
several choices..
1/ the caller of the timer may have given you indirect access to it in the
arg.
2/ maybe you juaast have to interate through all the vimages.. to do
whatever it is that you do
(that happens in some protocols)


On 2/1/11 11:04 AM, Monthadar Al Jaberi wrote:

On Tue, Feb 1, 2011 at 6:25 PM, Julian Elischerjul...@freebsd.org
  wrote:

On 2/1/11 8:40 AM, Monthadar Al Jaberi wrote:

Hi,

I hope I am on the write place, second try...

I have written a module that loads fake wifi devices (wtap?) and
distributes packets between them. For now I use route command to route
packets between them from upper layers (TCP,...).
I want to take it to next step and create jails with VNET. I started
reading Julian Elischer's Vimage: what is it? and he says that if I
am writing hardware drivers I dont need to make any changes when I
enable VIMAGE option on the kernel, because each one will have their
own stack.

I can give a more detailed explanation on how my module works. But for
now I get a panic when calling if_alloc() when using option VIMAGE.

Thank you,

while this  was true to some extent it i snot 100% true now.
during allocation we now try to have separate interface indexes per
vimage
which means that the setup routines do need to know the current vnet.

so I cant call if_alloc directly?


it looks like wtap_ioctl or wtap_attach should have the following:
(copied from the tun driver)

this should not be needed from real hardware based drivers as far as I
can
tell.

CURVNET_SET(CRED_TO_VNET(cred));
/* find any existing device, or allocate new unit number */
i = clone_create(tunclones,tun_cdevsw,u, dev, 0);
[blah]
if_clone_create(name, namelen, NULL);
CURVNET_RESTORE();

My wtap is based on ath driver code (if_ath.c) which should look like
a real device right?
if_ath.c is not using VNET, as far as I can tell

Currently my module creates a couple of wtaps, which I then create a
corresponding wlan. These wtaps are interconnected together, so no out
world yet... so I dont have struct cdev *dev

Basic idea is my module have a main queue (simulating air) and each
wtap have a rx_task which sends packets up to higher layers, plus
callout timer for generation beacons...

I will try to use CURVET_SET(...) tomo



My setup:
FreeBSD Current 201010 guest on VirtualBox on Ubuntu 10.04.

Kernel page fault with the following non-sleepable locks held:
exclusive rw ifnet_rw (ifnet_rw) r = 0 (0xc0fc8284) locked @
/usr/src/sys/net/if.c:414
KDB: stack backtrace:
db_trace_self_wrapper(c0cf3cdb,1,0,0,0,...) at
db_trace_self_wrapper+0x26
kdb_backtrace(19e,1,,c0f9b194,c2fc9a1c,...) at
kdb_backtrace+0x2a
_witness_debugger(c0cf6408,c2fc9a30,4,1,0,...) at _witness_debugger+0x25
witness_warn(5,0,c0d2c479,3,c4070d48,...) at witness_warn+0x1fe
trap(c2fc9abc) at trap+0x195
calltrap() at calltrap+0x6
--- trap 0xc, eip = 0xc0970999, esp = 0xc2fc9afc, ebp = 0xc2fc9b1c ---
ifindex_alloc_locked(c0d003cf,c2fc9b36,19e,19e,c15ab714,...) at
ifindex_alloc_locked+0x19

Re: simulating wireless device (if_alloc panic, VirtualBox, VIMAGE)

2011-02-02 Thread Julian Elischer

On 2/2/11 8:42 AM, Julian Elischer wrote:

On 2/2/11 7:06 AM, Monthadar Al Jaberi wrote:

Thanx makes more sense, but I have noticed something weired if you can
shade some light on.

I added printfs one when the module is first loaded (static int
event_handler(module_t module, int event, void *arg)):
curthread=0xc3f95870
curthread-td_vnet=0xc3170e00
curthread-td_ucred=0xc3185d00
TD_TO_VNET=0
CRED_TO_VNET=0


And same printf in wtap_ioctl which is called from a user space
program (I am root):
curthread=0xc3f952d0
curthread-td_vnet=0
curthread-td_ucred=0xc3185d00
TD_TO_VNET=0
CRED_TO_VNET=0


In both cases TD_TO_VNET/CRED_TO_VNET return NULL... shouldn't they
return a pointer same as curthread-td_vnet? Another thing is that in
wtap_ioctl curthread-td_vnet is NUL





that depends on where in your code you did the print..

have you read this file?

http://p4db.freebsd.org/fileViewer.cgi?FSPC=//depot/projects/vimage/porting_to_vimage.txtREV=18 


use the 'download' button to get a more readable version.

it goes into some of the details of this. especially the 
initialization or vimage modules.


oops sent too early.

I think you said you had seen it but read it again now that I have 
explained some of it to you and maybe

it will give new insights.

The VNET_SYSINIT() code will get called once for every vnet, and the 
current vnet is set up for you before it calls you.

it is also called once when you start  a NEW vnet..

this is the place where Marko jumps in because my head is currently 
full of other stuff from work and I

have paged the vimage stuff out to swap..  :-)








I still get a panic...

br,

On Tue, Feb 1, 2011 at 8:37 PM, Julian 
Elischerjul...@freebsd.org  wrote:

ok here's how it works..

any place you access a V_xxx variable you need to have the current 
vnet set.
so somewhere in your code path to get to that point you have to 
have done

CURVNET_SET() and after you have finised on the way out you should do
CURVNET_RESTORE().

you can get the vnet from several places:

1/ as shown below, you can get it from any thread's cred if teh 
running

thread is part of a
process in the jail in question.
2/ if you have an ifp pointer, you can use ifp-vnet  .   I think 
that's

right, it's been a while...
3/ I believe though I may be wrong  (I may be thinking of multi FIBS)
that it maybe in the socket structure too but don't trust me on 
that one..

check it.

if, like in a timer thread you have access to NONE of those, you have
several choices..
1/ the caller of the timer may have given you indirect access to 
it in the

arg.
2/ maybe you juaast have to interate through all the vimages.. to do
whatever it is that you do
(that happens in some protocols)


On 2/1/11 11:04 AM, Monthadar Al Jaberi wrote:

On Tue, Feb 1, 2011 at 6:25 PM, Julian Elischerjul...@freebsd.org
  wrote:

On 2/1/11 8:40 AM, Monthadar Al Jaberi wrote:

Hi,

I hope I am on the write place, second try...

I have written a module that loads fake wifi devices (wtap?) and
distributes packets between them. For now I use route command 
to route

packets between them from upper layers (TCP,...).
I want to take it to next step and create jails with VNET. I 
started
reading Julian Elischer's Vimage: what is it? and he says 
that if I

am writing hardware drivers I dont need to make any changes when I
enable VIMAGE option on the kernel, because each one will have 
their

own stack.

I can give a more detailed explanation on how my module works. 
But for
now I get a panic when calling if_alloc() when using option 
VIMAGE.


Thank you,

while this  was true to some extent it i snot 100% true now.
during allocation we now try to have separate interface indexes per
vimage
which means that the setup routines do need to know the current 
vnet.

so I cant call if_alloc directly?


it looks like wtap_ioctl or wtap_attach should have the following:
(copied from the tun driver)

this should not be needed from real hardware based drivers as 
far as I

can
tell.

CURVNET_SET(CRED_TO_VNET(cred));
/* find any existing device, or allocate new unit number */
i = clone_create(tunclones,tun_cdevsw,u, dev, 0);
[blah]
if_clone_create(name, namelen, NULL);
CURVNET_RESTORE();
My wtap is based on ath driver code (if_ath.c) which should look 
like

a real device right?
if_ath.c is not using VNET, as far as I can tell

Currently my module creates a couple of wtaps, which I then create a
corresponding wlan. These wtaps are interconnected together, so 
no out

world yet... so I dont have struct cdev *dev

Basic idea is my module have a main queue (simulating air) and each
wtap have a rx_task which sends packets up to higher layers, plus
callout timer for generation beacons...

I will try to use CURVET_SET(...) tomo



My setup:
FreeBSD Current 201010 guest on VirtualBox on Ubuntu 10.04.

Kernel page fault with the following non-sleepable locks held:
exclusive rw ifnet_rw (ifnet_rw) r = 0 (0xc0fc8284) locked @

Re: simulating wireless device (if_alloc panic, VirtualBox, VIMAGE)

2011-02-02 Thread Monthadar Al Jaberi
I just tried something that seems to work, but please dont hit me ^^;;;

in wtap_ioctl I assigned curthread-td_vnet myself to point to a VNET
(saved it when the module first loaded) (I have not created any jails
yet)... and it works... I didnt put any CURVNET macros...

my assumption is that if ath drivers dont use VNET I shouldnt :P

What is wrong with this hack?

br,

P.S. I have printed porting to vnet text to have it always at hand,
but its a bit hard for me... doing my best.

On Wed, Feb 2, 2011 at 6:30 PM, Julian Elischer jul...@freebsd.org wrote:
 On 2/2/11 9:12 AM, Bjoern A. Zeeb wrote:

 On Wed, 2 Feb 2011, Monthadar Al Jaberi wrote:

 Hi,

 Thanx makes more sense, but I have noticed something weired if you can
 shade some light on.

 I added printfs one when the module is first loaded (static int
 event_handler(module_t module, int event, void *arg)):
 curthread=0xc3f95870
 curthread-td_vnet=0xc3170e00
 curthread-td_ucred=0xc3185d00
 TD_TO_VNET=0
 CRED_TO_VNET=0

 Try to load it from laoder on boot; I think that should work as we are
 setting the curvent for the kernel startup.

 The problem you are seeing is a bug in the current implementation that
 you cannot add any physical network interface after the kernel started.
 This applies to cardbus/usb/... as well as any kind of ethernet
 interface, so a kldload igb should yield it as well.

 The fix for that is easy and hard at the same time:
 A) either touch all drivers
 B) or touch all cloned interfaces and change 3 common lines.
   or try to make cloners aware of vimages.

 Solution B) is sitting in perforce with the entire stuff that it depends
 on and was started with CH=179022,179255 but not limited to that if you
 want to have a peek.

 What you certainly can do locally to your driver for now is to make a
 change like this:

 +#ifdef VIMAGE
 +       CURVNET_SET(vnet0);
 +#endif
        ifp = if_alloc(IFT_ETHER);
 +#ifdef VIMAGE
 +       CURVNET_RESTORE();
 +#endif


 you don't really need  the #ifdef except for readability as CURVNET_XXX ar
 enot defined for !vnet

 It's the type A) kind of change from above that will break eventually
 in the future.

 /bz






-- 
//Monthadar Al Jaberi
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Re: simulating wireless device (if_alloc panic, VirtualBox, VIMAGE)

2011-02-02 Thread Julian Elischer

On 2/2/11 10:05 AM, Monthadar Al Jaberi wrote:

I just tried something that seems to work, but please dont hit me ^^;;;

in wtap_ioctl I assigned curthread-td_vnet myself to point to a VNET
(saved it when the module first loaded) (I have not created any jails
yet)... and it works... I didnt put any CURVNET macros...


td-td_vnet is exactly what the CURVNET_SET macro sets.
You should use the Macros because we may change the place where we 
store it.


The vnet for the current thread is picked up from several places 
depending on the context,
and it is cleared again when it is not needed.  the V_xxx usages in 
the code end up being
in effect expanded to curthread-td_vnet.xxx, where each 'xxx' is sort 
of like an element in a structure

but not quite.

Now, theoretically we could just leave it set all the time but then it 
would be nearly impossible
to find places where we should have changed it, but forgot and just 
got the existing one.


if you want to find the correct place to go, then look at the vnet of 
the calling process

which should be in the process cred. or just use vnet0.

I don't understand why you saw a CRED_TO_VNET of 0
I was under the impression that every process/thread in the system 
would be on vnet0

in a vimage kernel.

your stored vnet idea is ok as well, but may go strange if you load 
the driver from a vnet jail

and then remove the jail.





my assumption is that if ath drivers dont use VNET I shouldnt :P

What is wrong with this hack?

br,

P.S. I have printed porting to vnet text to have it always at hand,
but its a bit hard for me... doing my best.

On Wed, Feb 2, 2011 at 6:30 PM, Julian Elischerjul...@freebsd.org  wrote:

On 2/2/11 9:12 AM, Bjoern A. Zeeb wrote:

On Wed, 2 Feb 2011, Monthadar Al Jaberi wrote:

Hi,


Thanx makes more sense, but I have noticed something weired if you can
shade some light on.

I added printfs one when the module is first loaded (static int
event_handler(module_t module, int event, void *arg)):
curthread=0xc3f95870
curthread-td_vnet=0xc3170e00
curthread-td_ucred=0xc3185d00
TD_TO_VNET=0
CRED_TO_VNET=0

Try to load it from laoder on boot; I think that should work as we are
setting the curvent for the kernel startup.

The problem you are seeing is a bug in the current implementation that
you cannot add any physical network interface after the kernel started.
This applies to cardbus/usb/... as well as any kind of ethernet
interface, so a kldload igb should yield it as well.

The fix for that is easy and hard at the same time:
A) either touch all drivers
B) or touch all cloned interfaces and change 3 common lines.
   or try to make cloners aware of vimages.

Solution B) is sitting in perforce with the entire stuff that it depends
on and was started with CH=179022,179255 but not limited to that if you
want to have a peek.

What you certainly can do locally to your driver for now is to make a
change like this:

+#ifdef VIMAGE
+   CURVNET_SET(vnet0);
+#endif
ifp = if_alloc(IFT_ETHER);
+#ifdef VIMAGE
+   CURVNET_RESTORE();
+#endif


you don't really need  the #ifdef except for readability as CURVNET_XXX ar
enot defined for !vnet


It's the type A) kind of change from above that will break eventually
in the future.

/bz








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simulating wireless device (if_alloc panic, VirtualBox, VIMAGE)

2011-02-01 Thread Monthadar Al Jaberi
Hi,

I hope I am on the write place, second try...

I have written a module that loads fake wifi devices (wtap?) and
distributes packets between them. For now I use route command to route
packets between them from upper layers (TCP,...).
I want to take it to next step and create jails with VNET. I started
reading Julian Elischer's Vimage: what is it? and he says that if I
am writing hardware drivers I dont need to make any changes when I
enable VIMAGE option on the kernel, because each one will have their
own stack.

I can give a more detailed explanation on how my module works. But for
now I get a panic when calling if_alloc() when using option VIMAGE.

Thank you,


My setup:
FreeBSD Current 201010 guest on VirtualBox on Ubuntu 10.04.

Kernel page fault with the following non-sleepable locks held:
exclusive rw ifnet_rw (ifnet_rw) r = 0 (0xc0fc8284) locked @
/usr/src/sys/net/if.c:414
KDB: stack backtrace:
db_trace_self_wrapper(c0cf3cdb,1,0,0,0,...) at db_trace_self_wrapper+0x26
kdb_backtrace(19e,1,,c0f9b194,c2fc9a1c,...) at kdb_backtrace+0x2a
_witness_debugger(c0cf6408,c2fc9a30,4,1,0,...) at _witness_debugger+0x25
witness_warn(5,0,c0d2c479,3,c4070d48,...) at witness_warn+0x1fe
trap(c2fc9abc) at trap+0x195
calltrap() at calltrap+0x6
--- trap 0xc, eip = 0xc0970999, esp = 0xc2fc9afc, ebp = 0xc2fc9b1c ---
ifindex_alloc_locked(c0d003cf,c2fc9b36,19e,19e,c15ab714,...) at
ifindex_alloc_locked+0x19
if_alloc(47,c4085a16,3,c0de9614,c32aa780,...) at if_alloc+0x85
wtap_attach(c31a7800,c40857c0,0,4,0,...) at wtap_attach+0x29
new_wtap(c32aa780,0,c2fc9bf0,c083ac9b,c3cbb200,...) at new_wtap+0x9b
wtap_ioctl(c3cbb200,80045701,c31edaa0,1,c3f90b40,...) at wtap_ioctl+0x36
devfs_ioctl_f(c3cfe3b8,80045701,c31edaa0,c3185d00,c3f90b40,...) at
devfs_ioctl_f+0x10b
kern_ioctl(c3f90b40,3,80045701,c31edaa0,fc9cec,...) at kern_ioctl+0x20d
ioctl(c3f90b40,c2fc9cec,c2fc9d28,c0cf5783,0,...) at ioctl+0x134
syscallenter(c3f90b40,c2fc9ce4,c2fc9ce4,0,0,...) at syscallenter+0x263
syscall(c2fc9d28) at syscall+0x34
Xint0x80_syscall() at Xint0x80_syscall+0x21
--- syscall (54, FreeBSD ELF32, ioctl), eip = 0x28181203, esp =
0xbfbfec3c, ebp = 0xbfbfec58 ---


Fatal trap 12: page fault while in kernel mode
cpuid = 0; apic id = 00
fault virtual address   = 0x18
fault code  = supervisor read, page not present
instruction pointer = 0x20:0xc0970999
stack pointer   = 0x28:0xc2fc9afc
frame pointer   = 0x28:0xc2fc9b1c
code segment= base 0x0, limit 0xf, type 0x1b
   = DPL 0, pres 1, def32 1, gran 1
processor eflags= interrupt enabled, resume, IOPL = 0
current process = 1203 (ioctl)
panic: from debugger
cpuid = 0
Uptime: 21s
Physical memory: 495 MB
Dumping 55 MB: 40 24 8

-- 
//Monthadar Al Jaberi
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Re: simulating wireless device (if_alloc panic, VirtualBox, VIMAGE)

2011-02-01 Thread Julian Elischer

On 2/1/11 8:40 AM, Monthadar Al Jaberi wrote:

Hi,

I hope I am on the write place, second try...

I have written a module that loads fake wifi devices (wtap?) and
distributes packets between them. For now I use route command to route
packets between them from upper layers (TCP,...).
I want to take it to next step and create jails with VNET. I started
reading Julian Elischer's Vimage: what is it? and he says that if I
am writing hardware drivers I dont need to make any changes when I
enable VIMAGE option on the kernel, because each one will have their
own stack.

I can give a more detailed explanation on how my module works. But for
now I get a panic when calling if_alloc() when using option VIMAGE.

Thank you,


while this  was true to some extent it i snot 100% true now.
during allocation we now try to have separate interface indexes per vimage
which means that the setup routines do need to know the current vnet.

it looks like wtap_ioctl or wtap_attach should have the following:
(copied from the tun driver)

this should not be needed from real hardware based drivers as far as I 
can tell.


CURVNET_SET(CRED_TO_VNET(cred));
/* find any existing device, or allocate new unit number */
i = clone_create(tunclones, tun_cdevsw, u, dev, 0);
[blah]
if_clone_create(name, namelen, NULL);
CURVNET_RESTORE();


My setup:
FreeBSD Current 201010 guest on VirtualBox on Ubuntu 10.04.

Kernel page fault with the following non-sleepable locks held:
exclusive rw ifnet_rw (ifnet_rw) r = 0 (0xc0fc8284) locked @
/usr/src/sys/net/if.c:414
KDB: stack backtrace:
db_trace_self_wrapper(c0cf3cdb,1,0,0,0,...) at db_trace_self_wrapper+0x26
kdb_backtrace(19e,1,,c0f9b194,c2fc9a1c,...) at kdb_backtrace+0x2a
_witness_debugger(c0cf6408,c2fc9a30,4,1,0,...) at _witness_debugger+0x25
witness_warn(5,0,c0d2c479,3,c4070d48,...) at witness_warn+0x1fe
trap(c2fc9abc) at trap+0x195
calltrap() at calltrap+0x6
--- trap 0xc, eip = 0xc0970999, esp = 0xc2fc9afc, ebp = 0xc2fc9b1c ---
ifindex_alloc_locked(c0d003cf,c2fc9b36,19e,19e,c15ab714,...) at
ifindex_alloc_locked+0x19
if_alloc(47,c4085a16,3,c0de9614,c32aa780,...) at if_alloc+0x85
wtap_attach(c31a7800,c40857c0,0,4,0,...) at wtap_attach+0x29
new_wtap(c32aa780,0,c2fc9bf0,c083ac9b,c3cbb200,...) at new_wtap+0x9b
wtap_ioctl(c3cbb200,80045701,c31edaa0,1,c3f90b40,...) at wtap_ioctl+0x36
devfs_ioctl_f(c3cfe3b8,80045701,c31edaa0,c3185d00,c3f90b40,...) at
devfs_ioctl_f+0x10b
kern_ioctl(c3f90b40,3,80045701,c31edaa0,fc9cec,...) at kern_ioctl+0x20d
ioctl(c3f90b40,c2fc9cec,c2fc9d28,c0cf5783,0,...) at ioctl+0x134
syscallenter(c3f90b40,c2fc9ce4,c2fc9ce4,0,0,...) at syscallenter+0x263
syscall(c2fc9d28) at syscall+0x34
Xint0x80_syscall() at Xint0x80_syscall+0x21
--- syscall (54, FreeBSD ELF32, ioctl), eip = 0x28181203, esp =
0xbfbfec3c, ebp = 0xbfbfec58 ---


Fatal trap 12: page fault while in kernel mode
cpuid = 0; apic id = 00
fault virtual address   = 0x18
fault code  = supervisor read, page not present
instruction pointer = 0x20:0xc0970999
stack pointer   = 0x28:0xc2fc9afc
frame pointer   = 0x28:0xc2fc9b1c
code segment= base 0x0, limit 0xf, type 0x1b
= DPL 0, pres 1, def32 1, gran 1
processor eflags= interrupt enabled, resume, IOPL = 0
current process = 1203 (ioctl)
panic: from debugger
cpuid = 0
Uptime: 21s
Physical memory: 495 MB
Dumping 55 MB: 40 24 8



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Re: simulating wireless device (if_alloc panic, VirtualBox, VIMAGE)

2011-02-01 Thread Monthadar Al Jaberi
On Tue, Feb 1, 2011 at 6:25 PM, Julian Elischer jul...@freebsd.org wrote:
 On 2/1/11 8:40 AM, Monthadar Al Jaberi wrote:

 Hi,

 I hope I am on the write place, second try...

 I have written a module that loads fake wifi devices (wtap?) and
 distributes packets between them. For now I use route command to route
 packets between them from upper layers (TCP,...).
 I want to take it to next step and create jails with VNET. I started
 reading Julian Elischer's Vimage: what is it? and he says that if I
 am writing hardware drivers I dont need to make any changes when I
 enable VIMAGE option on the kernel, because each one will have their
 own stack.

 I can give a more detailed explanation on how my module works. But for
 now I get a panic when calling if_alloc() when using option VIMAGE.

 Thank you,

 while this  was true to some extent it i snot 100% true now.
 during allocation we now try to have separate interface indexes per vimage
 which means that the setup routines do need to know the current vnet.

so I cant call if_alloc directly?


 it looks like wtap_ioctl or wtap_attach should have the following:
 (copied from the tun driver)

 this should not be needed from real hardware based drivers as far as I can
 tell.

        CURVNET_SET(CRED_TO_VNET(cred));
        /* find any existing device, or allocate new unit number */
        i = clone_create(tunclones, tun_cdevsw, u, dev, 0);
        [blah]
        if_clone_create(name, namelen, NULL);
        CURVNET_RESTORE();

My wtap is based on ath driver code (if_ath.c) which should look like
a real device right?
if_ath.c is not using VNET, as far as I can tell

Currently my module creates a couple of wtaps, which I then create a
corresponding wlan. These wtaps are interconnected together, so no out
world yet... so I dont have struct cdev *dev

Basic idea is my module have a main queue (simulating air) and each
wtap have a rx_task which sends packets up to higher layers, plus
callout timer for generation beacons...

I will try to use CURVET_SET(...) tomo



 My setup:
 FreeBSD Current 201010 guest on VirtualBox on Ubuntu 10.04.

 Kernel page fault with the following non-sleepable locks held:
 exclusive rw ifnet_rw (ifnet_rw) r = 0 (0xc0fc8284) locked @
 /usr/src/sys/net/if.c:414
 KDB: stack backtrace:
 db_trace_self_wrapper(c0cf3cdb,1,0,0,0,...) at db_trace_self_wrapper+0x26
 kdb_backtrace(19e,1,,c0f9b194,c2fc9a1c,...) at kdb_backtrace+0x2a
 _witness_debugger(c0cf6408,c2fc9a30,4,1,0,...) at _witness_debugger+0x25
 witness_warn(5,0,c0d2c479,3,c4070d48,...) at witness_warn+0x1fe
 trap(c2fc9abc) at trap+0x195
 calltrap() at calltrap+0x6
 --- trap 0xc, eip = 0xc0970999, esp = 0xc2fc9afc, ebp = 0xc2fc9b1c ---
 ifindex_alloc_locked(c0d003cf,c2fc9b36,19e,19e,c15ab714,...) at
 ifindex_alloc_locked+0x19
 if_alloc(47,c4085a16,3,c0de9614,c32aa780,...) at if_alloc+0x85
 wtap_attach(c31a7800,c40857c0,0,4,0,...) at wtap_attach+0x29
 new_wtap(c32aa780,0,c2fc9bf0,c083ac9b,c3cbb200,...) at new_wtap+0x9b
 wtap_ioctl(c3cbb200,80045701,c31edaa0,1,c3f90b40,...) at wtap_ioctl+0x36
 devfs_ioctl_f(c3cfe3b8,80045701,c31edaa0,c3185d00,c3f90b40,...) at
 devfs_ioctl_f+0x10b
 kern_ioctl(c3f90b40,3,80045701,c31edaa0,fc9cec,...) at kern_ioctl+0x20d
 ioctl(c3f90b40,c2fc9cec,c2fc9d28,c0cf5783,0,...) at ioctl+0x134
 syscallenter(c3f90b40,c2fc9ce4,c2fc9ce4,0,0,...) at syscallenter+0x263
 syscall(c2fc9d28) at syscall+0x34
 Xint0x80_syscall() at Xint0x80_syscall+0x21
 --- syscall (54, FreeBSD ELF32, ioctl), eip = 0x28181203, esp =
 0xbfbfec3c, ebp = 0xbfbfec58 ---


 Fatal trap 12: page fault while in kernel mode
 cpuid = 0; apic id = 00
 fault virtual address   = 0x18
 fault code              = supervisor read, page not present
 instruction pointer     = 0x20:0xc0970999
 stack pointer           = 0x28:0xc2fc9afc
 frame pointer           = 0x28:0xc2fc9b1c
 code segment            = base 0x0, limit 0xf, type 0x1b
                        = DPL 0, pres 1, def32 1, gran 1
 processor eflags        = interrupt enabled, resume, IOPL = 0
 current process         = 1203 (ioctl)
 panic: from debugger
 cpuid = 0
 Uptime: 21s
 Physical memory: 495 MB
 Dumping 55 MB: 40 24 8






-- 
//Monthadar Al Jaberi
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Re: simulating wireless device (if_alloc panic, VirtualBox, VIMAGE)

2011-02-01 Thread Julian Elischer

ok here's how it works..

any place you access a V_xxx variable you need to have the current 
vnet set.

so somewhere in your code path to get to that point you have to have done
CURVNET_SET() and after you have finised on the way out you should do
CURVNET_RESTORE().

you can get the vnet from several places:

1/ as shown below, you can get it from any thread's cred if teh 
running thread is part of a

process in the jail in question.
2/ if you have an ifp pointer, you can use ifp-vnet  .   I think 
that's right, it's been a while...

3/ I believe though I may be wrong  (I may be thinking of multi FIBS)
that it maybe in the socket structure too but don't trust me on that 
one.. check it.


if, like in a timer thread you have access to NONE of those, you have 
several choices..
1/ the caller of the timer may have given you indirect access to it in 
the arg.
2/ maybe you juaast have to interate through all the vimages.. to do 
whatever it is that you do

(that happens in some protocols)


On 2/1/11 11:04 AM, Monthadar Al Jaberi wrote:

On Tue, Feb 1, 2011 at 6:25 PM, Julian Elischerjul...@freebsd.org  wrote:

On 2/1/11 8:40 AM, Monthadar Al Jaberi wrote:

Hi,

I hope I am on the write place, second try...

I have written a module that loads fake wifi devices (wtap?) and
distributes packets between them. For now I use route command to route
packets between them from upper layers (TCP,...).
I want to take it to next step and create jails with VNET. I started
reading Julian Elischer's Vimage: what is it? and he says that if I
am writing hardware drivers I dont need to make any changes when I
enable VIMAGE option on the kernel, because each one will have their
own stack.

I can give a more detailed explanation on how my module works. But for
now I get a panic when calling if_alloc() when using option VIMAGE.

Thank you,

while this  was true to some extent it i snot 100% true now.
during allocation we now try to have separate interface indexes per vimage
which means that the setup routines do need to know the current vnet.

so I cant call if_alloc directly?


it looks like wtap_ioctl or wtap_attach should have the following:
(copied from the tun driver)

this should not be needed from real hardware based drivers as far as I can
tell.

CURVNET_SET(CRED_TO_VNET(cred));
/* find any existing device, or allocate new unit number */
i = clone_create(tunclones,tun_cdevsw,u, dev, 0);
[blah]
if_clone_create(name, namelen, NULL);
CURVNET_RESTORE();

My wtap is based on ath driver code (if_ath.c) which should look like
a real device right?
if_ath.c is not using VNET, as far as I can tell

Currently my module creates a couple of wtaps, which I then create a
corresponding wlan. These wtaps are interconnected together, so no out
world yet... so I dont have struct cdev *dev

Basic idea is my module have a main queue (simulating air) and each
wtap have a rx_task which sends packets up to higher layers, plus
callout timer for generation beacons...

I will try to use CURVET_SET(...) tomo



My setup:
FreeBSD Current 201010 guest on VirtualBox on Ubuntu 10.04.

Kernel page fault with the following non-sleepable locks held:
exclusive rw ifnet_rw (ifnet_rw) r = 0 (0xc0fc8284) locked @
/usr/src/sys/net/if.c:414
KDB: stack backtrace:
db_trace_self_wrapper(c0cf3cdb,1,0,0,0,...) at db_trace_self_wrapper+0x26
kdb_backtrace(19e,1,,c0f9b194,c2fc9a1c,...) at kdb_backtrace+0x2a
_witness_debugger(c0cf6408,c2fc9a30,4,1,0,...) at _witness_debugger+0x25
witness_warn(5,0,c0d2c479,3,c4070d48,...) at witness_warn+0x1fe
trap(c2fc9abc) at trap+0x195
calltrap() at calltrap+0x6
--- trap 0xc, eip = 0xc0970999, esp = 0xc2fc9afc, ebp = 0xc2fc9b1c ---
ifindex_alloc_locked(c0d003cf,c2fc9b36,19e,19e,c15ab714,...) at
ifindex_alloc_locked+0x19
if_alloc(47,c4085a16,3,c0de9614,c32aa780,...) at if_alloc+0x85
wtap_attach(c31a7800,c40857c0,0,4,0,...) at wtap_attach+0x29
new_wtap(c32aa780,0,c2fc9bf0,c083ac9b,c3cbb200,...) at new_wtap+0x9b
wtap_ioctl(c3cbb200,80045701,c31edaa0,1,c3f90b40,...) at wtap_ioctl+0x36
devfs_ioctl_f(c3cfe3b8,80045701,c31edaa0,c3185d00,c3f90b40,...) at
devfs_ioctl_f+0x10b
kern_ioctl(c3f90b40,3,80045701,c31edaa0,fc9cec,...) at kern_ioctl+0x20d
ioctl(c3f90b40,c2fc9cec,c2fc9d28,c0cf5783,0,...) at ioctl+0x134
syscallenter(c3f90b40,c2fc9ce4,c2fc9ce4,0,0,...) at syscallenter+0x263
syscall(c2fc9d28) at syscall+0x34
Xint0x80_syscall() at Xint0x80_syscall+0x21
--- syscall (54, FreeBSD ELF32, ioctl), eip = 0x28181203, esp =
0xbfbfec3c, ebp = 0xbfbfec58 ---


Fatal trap 12: page fault while in kernel mode
cpuid = 0; apic id = 00
fault virtual address   = 0x18
fault code  = supervisor read, page not present
instruction pointer = 0x20:0xc0970999
stack pointer   = 0x28:0xc2fc9afc
frame pointer   = 0x28:0xc2fc9b1c
code segment= base 0x0, limit 0xf, type 0x1b
= DPL 0, pres 1, def32 1, gran 1
processor eflags=