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References: <20161205195638.7005-1-shuahkh@osg.samsung.com> <4a3b7e4f-6b5c-d9e8-f26c-1286d4e1f630@osg.samsung.com>
From: Andrey Konovalov <andreyknvl@google.com>
Date: Tue, 6 Dec 2016 13:06:40 +0100
Message-ID: <CAAeHK+ycHQS7Hbamt-A3MHORGrvH8UmW7KdiEA==V1z8wdnwEA@mail.gmail.com>
Subject: Re: [PATCH] usbip: fix warning in vhci_hcd_probe/lockdep_init_map
To: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Valentina Manea <valentina.manea.m@gmail.com>,
        Shuah Khan <shuah@kernel.org>, linux-usb@vger.kernel.org,
        LKML <linux-kernel@vger.kernel.org>
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On Mon, Dec 5, 2016 at 9:00 PM, Shuah Khan <shuahkh@osg.samsung.com> wrote:
> Hi Andrey,
>
> On 12/05/2016 12:56 PM, Shuah Khan wrote:
>> vhci_hcd calls sysfs_create_group() with dynamically allocated sysfs
>> attributes triggering the lock-class key not persistent warning. Call
>> sysfs_attr_init() for dynamically allocated sysfs attributes to fix it.
>>
>> vhci_hcd vhci_hcd: USB/IP Virtual Host Controller
>> vhci_hcd vhci_hcd: new USB bus registered, assigned bus number 2
>> BUG: key ffff88006a7e8d18 not in .data!
>> ------------[ cut here ]------------
>> WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:3131
>> lockdep_init_map+0x60c/0x770
>> DEBUG_LOCKS_WARN_ON(1)[    1.567044] Modules linked in:
>> CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.9.0-rc7+ #58
>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>>  ffff88006bce6eb8 ffffffff81f96c8a ffffffff00000a02 1ffff1000d79cd6a
>>  ffffed000d79cd62 000000046bce6ed8 0000000041b58ab3 ffffffff8598af40
>>  ffffffff81f969f8 0000000000000000 0000000041b58ab3 0000000000000200
>> Call Trace:
>>  [<     inline     >] __dump_stack lib/dump_stack.c:15
>>  [<ffffffff81f96c8a>] dump_stack+0x292/0x398 lib/dump_stack.c:51
>>  [<ffffffff812b808f>] __warn+0x19f/0x1e0 kernel/panic.c:550
>>  [<ffffffff812b8195>] warn_slowpath_fmt+0xc5/0x110 kernel/panic.c:565
>>  [<ffffffff813f3efc>] lockdep_init_map+0x60c/0x770 kernel/locking/lockdep.c:3131
>>  [<ffffffff819e43d4>] __kernfs_create_file+0x114/0x2a0 fs/kernfs/file.c:954
>>  [<ffffffff819e68f5>] sysfs_add_file_mode_ns+0x225/0x520 fs/sysfs/file.c:305
>>  [<     inline     >] create_files fs/sysfs/group.c:64
>>  [<ffffffff819e8a89>] internal_create_group+0x239/0x8f0 fs/sysfs/group.c:134
>>  [<ffffffff819e915f>] sysfs_create_group+0x1f/0x30 fs/sysfs/group.c:156
>>  [<ffffffff8323de24>] vhci_start+0x5b4/0x7a0 drivers/usb/usbip/vhci_hcd.c:978
>>  [<ffffffff82c907ca>] usb_add_hcd+0x8da/0x1c60 drivers/usb/core/hcd.c:2867
>>  [<ffffffff8323bc57>] vhci_hcd_probe+0x97/0x130
>> drivers/usb/usbip/vhci_hcd.c:1103
>>  ---
>>  ---
>> ---[ end trace c33c7b202cf3aac8 ]---
>>
>> Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
>> Reported-by: Andrey Konovalov <andreyknvl@google.com>
>
> Here is the fix. Fixed the warning I reproduced on my system.
> Let me know if it works for you.

Hi Shuah,

This fixes the warning I've been seeing.

Thanks!

>
> thanks,
> -- Shuah
>
>> ---
>>  drivers/usb/usbip/vhci_sysfs.c | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/usb/usbip/vhci_sysfs.c b/drivers/usb/usbip/vhci_sysfs.c
>> index c404017..b96e5b1 100644
>> --- a/drivers/usb/usbip/vhci_sysfs.c
>> +++ b/drivers/usb/usbip/vhci_sysfs.c
>> @@ -361,6 +361,7 @@ static void set_status_attr(int id)
>>       status->attr.attr.name = status->name;
>>       status->attr.attr.mode = S_IRUGO;
>>       status->attr.show = status_show;
>> +     sysfs_attr_init(&status->attr.attr);
>>  }
>>
>>  static int init_status_attrs(void)
>>
>