* Oops calling sysfs_create_link() from pci_probe()
@ 2005-06-16 19:57 Luben Tuikov
2005-06-17 5:55 ` Greg KH
0 siblings, 1 reply; 3+ messages in thread
From: Luben Tuikov @ 2005-06-16 19:57 UTC (permalink / raw)
To: Linux Kernel Mailing List
Hi,
I'm calling
sysfs_create_link(&class->kobj,
&pcidev->driver->driver.kobj, "driver");
To create a link from a syfs directory of an object which I've
created with class_device_regsiter(), to point to the
driver directory of the pci driver.
This is effectively called at the bottom of the pci_driver->probe
function.
But I get this oops:
printing eip:
c0229e7b
*pde = 00000000
Oops: 0000 [#1]
PREEMPT SMP
Modules linked in: aic94xx sas_class
CPU: 0
EIP: 0060:[<c0229e7b>] Not tainted VLI
EFLAGS: 00010296 (2.6.12-rc6)
EIP is at kref_get+0xb/0x50
eax: 00000060 ebx: 00000060 ecx: 00000000 edx: 0000002c
esi: e09342cb edi: df02a997 ebp: fffffff4 esp: d5a81e0c
ds: 007b es: 007b ss: 0068
Process insmod (pid: 3166, threadinfo=d5a80000 task=df6bc540)
Stack: c014653b dfff5080 000000d0 df02a98c 00000048 c02293aa 00000060 d35257ac
c0195d77 00000048 000000d0 c022948e decdc040 c0229460 d335d4b0 c2a0b530
00000000 decdc020 decdc014 c0195e0f c2a0b530 e09342c4 00000048 e0935180
Call Trace:
[<c014653b>] __kmalloc+0x9b/0xd0
[<c02293aa>] kobject_get+0x1a/0x30
[<c0195d77>] sysfs_add_link+0x77/0xd0
[<c022948e>] kobject_put+0x1e/0x30
[<c0229460>] kobject_release+0x0/0x10
[<c0195e0f>] sysfs_create_link+0x3f/0x70
[<e093419e>] sas_register_ha+0x10e/0x160 [sas_class]
[<e0a6cf67>] asd_pci_probe+0x6b7/0x760 [aic94xx]
[<c0235a62>] pci_device_probe_static+0x52/0x70
[<c0235abc>] __pci_device_probe+0x3c/0x50
[<c0235afc>] pci_device_probe+0x2c/0x50
[<c026d40f>] driver_probe_device+0x2f/0x80
[<c026d55c>] driver_attach+0x5c/0x90
[<c026da8e>] bus_add_driver+0x9e/0xd0
[<c0235dbd>] pci_register_driver+0x7d/0xa0
[<e0814044>] aic94xx_init+0x44/0x58 [aic94xx]
[<c01389a3>] sys_init_module+0x223/0x250
[<c0102fb5>] syscall_call+0x7/0xb
Code: 92 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 8b 44 24 04 c7 00 01 00 00 00 c3 90 8d 74 26 00 83 ec 14 89 5c 24 10 8b 5c 24 18 <8b> 03 85 c0 74 0b f0 ff 03 8b 5c 24 10 83 c4 14 c3 c7 04 24 fa
Which suggests that I cannot call this from inside pci_probe(),
but will have to "wait" to call it after pci_regsiter_driver()
returns, effectively after pci_populate_driver_dir() returns.
Is this correct assumption? Or can I call the syslink call
above in other ways?
Thanks,
Luben
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Oops calling sysfs_create_link() from pci_probe()
2005-06-16 19:57 Oops calling sysfs_create_link() from pci_probe() Luben Tuikov
@ 2005-06-17 5:55 ` Greg KH
2005-06-17 16:23 ` Luben Tuikov
0 siblings, 1 reply; 3+ messages in thread
From: Greg KH @ 2005-06-17 5:55 UTC (permalink / raw)
To: Luben Tuikov; +Cc: Linux Kernel Mailing List
On Thu, Jun 16, 2005 at 03:57:34PM -0400, Luben Tuikov wrote:
> Hi,
>
> I'm calling
>
> sysfs_create_link(&class->kobj,
> &pcidev->driver->driver.kobj, "driver");
>
> To create a link from a syfs directory of an object which I've
> created with class_device_regsiter(), to point to the
> driver directory of the pci driver.
Ick, why? Shouldn't something like this be done in the driver core, and
not in the individual drivers?
> This is effectively called at the bottom of the pci_driver->probe
> function.
>
> But I get this oops:
> printing eip:
> c0229e7b
> *pde = 00000000
> Oops: 0000 [#1]
> PREEMPT SMP
> Modules linked in: aic94xx sas_class
> CPU: 0
> EIP: 0060:[<c0229e7b>] Not tainted VLI
> EFLAGS: 00010296 (2.6.12-rc6)
> EIP is at kref_get+0xb/0x50
Looks like one of the kobjects that you are wanting to link is not fully
initialized and registered with sysfs. Where are you getting that
"&class->kobj" from?
Have a pointer to your patch anywhere?
Also, try turning on kobject and driver core debugging, you should get a
lot of helpful information in your syslog right before this oops.
thanks,
greg k-h
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Oops calling sysfs_create_link() from pci_probe()
2005-06-17 5:55 ` Greg KH
@ 2005-06-17 16:23 ` Luben Tuikov
0 siblings, 0 replies; 3+ messages in thread
From: Luben Tuikov @ 2005-06-17 16:23 UTC (permalink / raw)
To: Greg KH; +Cc: Linux Kernel Mailing List
On 06/17/05 01:55, Greg KH wrote:
> On Thu, Jun 16, 2005 at 03:57:34PM -0400, Luben Tuikov wrote:
>
>>Hi,
>>
>>I'm calling
>>
>>sysfs_create_link(&class->kobj,
>> &pcidev->driver->driver.kobj, "driver");
>>
>>To create a link from a syfs directory of an object which I've
>>created with class_device_regsiter(), to point to the
>>driver directory of the pci driver.
>
>
> Ick, why? Shouldn't something like this be done in the driver core, and
> not in the individual drivers?
Hi Greg,
I agree, it should be done in the driver core. The LLDD is registering
with the SAS class (unfinished, incomplete) and this is what appears:
/sys/class/sas/
/sys/class/sas/ha0/
/sys/class/sas/ha0/device -> link to PCI device
/sys/class/sas/ha0/device_name
where device name is the SAS address attribute (RO).
I'd ideally like to have a link to the LLDD in there
as well:
/sys/class/sas/ha0/driver -> link to the driver
But this host adapter registration with the SAS class happens
at pci_probe time, *at pci_register_driver* time so it seems that this
is the reason for the oops. (as opposed to PCI hot plugging the controller)
> Looks like one of the kobjects that you are wanting to link is not fully
> initialized and registered with sysfs. Where are you getting that
> "&class->kobj" from?
It is the kobj of "ha0" which was just registered with class_device_register().
I suspect since all this is called from pci_probe at module init, it is
failing for the 2nd kobj, the driver.
Would this imply that had pci_probe been called on a PCI hot plug event
(not at pci_driver_register() time) then that symlink would've succeeded?
(since the driver had been registered already)
If so, can we reconcile this somehow so that code executed in pci_probe
at time B, could've also been executed at time A, A < B?
> Have a pointer to your patch anywhere?
It is quite incomplete. Let me have something substantial and I'll post it
and then we can figure it out. For now that line is /* XXX it would be good... */
> Also, try turning on kobject and driver core debugging, you should get a
> lot of helpful information in your syslog right before this oops.
Thanks,
Luben
^ permalink raw reply [flat|nested] 3+ messages in thread
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2005-06-16 19:57 Oops calling sysfs_create_link() from pci_probe() Luben Tuikov
2005-06-17 5:55 ` Greg KH
2005-06-17 16:23 ` Luben Tuikov
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