Re: [GIT PATCH] USB patches for 2.6.17

Greg KH
2006-06-23T00:59:37Z

On Thu, Jun 22, 2006 at 04:11:26PM -0700, Linus Torvalds wrote:
>
>
> On Wed, 21 Jun 2006, Greg KH wrote:
> >
> > Here are a lot of USB patches for 2.6.17. They do the following:
>
> I think these may be responsible for:
>
> Bluetooth: L2CAP ver 2.8
> Bluetooth: L2CAP socket layer initialized
> Bluetooth: HIDP (Human Interface Emulation) ver 1.1
> Bluetooth: RFCOMM socket layer initialized
> Bluetooth: RFCOMM TTY layer initialized
> Bluetooth: RFCOMM ver 1.7
> BUG: unable to handle kernel paging request at virtual address 5a5a5a5a
> printing eip:
> c02a58f8
> *pde = 00000000
> Oops: 0000 [#1]
> SMP
> Modules linked in: rfcomm hidp l2cap hci_usb bluetooth ip_conntrack_netbios_ns ipt_REJECT iptable_filter ip_tables ip6table_filter ip6_tables cpufreq_ondemand lp pcspkr intel_agp agpgart
> CPU: 0
> EIP: 0060:[<c02a58f8>] Not tainted VLI
> EFLAGS: 00210206 (2.6.17-gd588fcbe #211)
> EIP is at usbdev_open+0xb4/0x1ec
> eax: 0bd00005 ebx: 5a5a5a5a ecx: 5a5a58d2 edx: dd991e4c
> esi: de020bdc edi: c712da68 ebp: c6eeaee8 esp: c6eeaeac
> ds: 007b es: 007b ss: 0068
> Process hid2hci (pid: 3719, threadinfo=c6eea000 task=ddfb8570)
> Stack: c854dc28 dd22cd70 00000000 00000005 c6eeaed4 c016bd39 c6eeaf3c 00000001
> c6eea000 00000000 dd22cd70 c6eeaee8 00000000 c050b8a0 dd22cd70 c6eeaf04
> c01678a4 c854dc28 c6eeaf04 c854dc28 dd22cd70 00000000 c6eeaf20 c015e424
> Call Trace:
> <c0103c46> show_stack_log_lvl+0x85/0x8f <c0103dc3> show_registers+0x13b/0x1af
> <c0103fac> die+0x175/0x285 <c011a86d> do_page_fault+0x428/0x522
> <c0103777> error_code+0x4f/0x54 <c01678a4> chrdev_open+0x11a/0x171
> <c015e424> __dentry_open+0xc8/0x1ab <c015e575> nameidata_to_filp+0x1c/0x2e
> <c015e5b5> do_filp_open+0x2e/0x35 <c015e5fc> do_sys_open+0x40/0xba
> <c015e6a2> sys_open+0x16/0x18 <c0102c0f> sysenter_past_esp+0x54/0x75
> Code: 00 8b 35 cc 77 61 c0 8b 8e 9c 00 00 00 81 e9 88 01 00 00 eb 16 8b 45 d0 0d 00 00 d0 0b 39 81 94 01 00 00 74 81 8d 8b 78
> fe ff ff <8b> 99 88 01 00 00 0f 18 03 90 8d 91 88 01 00 00 8d 86 9c 00 00
> EIP: [<c02a58f8>] usbdev_open+0xb4/0x1ec SS:ESP 0068:c6eeaeac
>
> where that 5a5a5a5a is possibly/probably due to SLAB debugging (it's the
> "POISON_INUSE" pattern)
>
> It might have happened before too, of course, I just haven't seen it
> before (even though I've had SLAB debugging on all the time on that
> machine).
>
> It seems to actually be from usbdev_lookup_minor(), which has been inlined
> (damn compiler), and it's the "node.next" access in the
>
> list_for_each_entry(device, &usb_device_class->devices, node) {
>
> loop.
>
> Any ideas?

Ok, this was a stupid one on my part, I'm really surprised that it
didn't trigger all the time. Here's a patch for it. Sorry about this.

This just survived a lot of unloads and reloads and devices disappearing
and added.

thanks,

greg k-h

---------------------

From: Greg Kroah-Hartman <gregkh@suse.de>
Subject: Driver core: fix locking issues with the devices that are attached to classes

Doh, that was foolish...

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/base/core.c | 19 +++++++++++--------
1 file changed, 11 insertions(+), 8 deletions(-)

--- gregkh-2.6.orig/drivers/base/core.c
+++ gregkh-2.6/drivers/base/core.c
@@ -356,6 +356,13 @@ int device_add(struct device *dev)
if (parent)
klist_add_tail(&dev->knode_parent, &parent->klist_children);

+ if (dev->class) {
+ /* tie the class to the device */
+ down(&dev->class->sem);
+ list_add_tail(&dev->node, &dev->class->devices);
+ up(&dev->class->sem);
+ }
+
/* notify platform of device entry */
if (platform_notify)
platform_notify(dev);
@@ -456,6 +463,9 @@ void device_del(struct device * dev)
sysfs_remove_link(&dev->kobj, "device");
sysfs_remove_link(&dev->parent->kobj, class_name);
kfree(class_name);
+ down(&dev->class->sem);
+ list_del_init(&dev->node);
+ up(&dev->class->sem);
}
device_remove_file(dev, &dev->uevent_attr);

@@ -602,11 +612,6 @@ struct device *device_create(struct clas
if (retval)
goto error;

- /* tie the class to the device */
- down(&class->sem);
- list_add_tail(&dev->node, &class->devices);
- up(&class->sem);
-
return dev;

error:
@@ -637,9 +642,7 @@ void device_destroy(struct class *class,
}
up(&class->sem);

- if (dev) {
- list_del_init(&dev->node);
+ if (dev)
device_unregister(dev);
- }
}
EXPORT_SYMBOL_GPL(device_destroy);