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From: Shuah Khan <skhan@linuxfoundation.org>
To: xndcn <xndchn@gmail.com>
Cc: Valentina Manea <valentina.manea.m@gmail.com>,
	Shuah Khan <shuah@kernel.org>, Hongren Zheng <i@zenithal.me>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"open list:USB OVER IP DRIVER" <linux-usb@vger.kernel.org>,
	open list <linux-kernel@vger.kernel.org>,
	Shuah Khan <skhan@linuxfoundation.org>
Subject: Re: [PATCH 1/2] usbip: Fix seqnum sign extension issue in vhci_tx_urb
Date: Thu, 9 Jan 2025 09:02:36 -0700	[thread overview]
Message-ID: <2ff39cff-af3c-4020-81b3-4238efe6c2e3@linuxfoundation.org> (raw)
In-Reply-To: <CAJ=gGT3pAnKUCve1OV5SXVArz6HUdizu9wjM5tPJ_CrQ=sF=nw@mail.gmail.com>

On 1/3/25 08:18, xndcn wrote:
> Thanks.
> 
>> How did you find the problem?
>> Why does it make sense to cast it to u32?
> 
> After running with usbip enough time, I happened to see logs like this:
>> [ 293.863125] vhci_hcd vhci_hcd.0: Device attached
>> [ 294.081110] usb 1-1: new high-speed USB device number 2 using vhci_hcd
>> [ 294.193163] usb 1-1: SetAddress Request (2) to port 0
>> [ 294.204334] vhci_hcd: cannot find a urb of seqnum 2147483648 max seqnum -2147483648
>> [ 294.204850] vhci_hcd: stop threads
>> [ 294.204851] vhci_hcd: release socket
>> [ 294.204853] vhci_hcd: disconnect device
> 
> Then I notice that on 64bit platform, when
> atomic_inc_return(&vhci_hcd->seqnum) returns (2147483647 + 1, or
> 0x80000000),
> priv->seqnum (which is unsigned long, i.e. u64 on 64bit) will be
> extends to 0xffffffff80000000
> So we can fix the issue by cast it to u32.
> 

Can you send me the dmesg without and with your patch?

thanks,
-- Shuah


  reply	other threads:[~2025-01-09 16:02 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-12-31 16:15 [PATCH 0/2] usbip: Fix seqnum sign extension and format specifier issues Xiong Nandi
2024-12-31 16:15 ` [PATCH 1/2] usbip: Fix seqnum sign extension issue in vhci_tx_urb Xiong Nandi
2025-01-02 22:06   ` Shuah Khan
2025-01-03 15:18     ` xndcn
2025-01-09 16:02       ` Shuah Khan [this message]
2025-01-13 13:29         ` xndcn
2025-01-15 21:14   ` Shuah Khan
2024-12-31 16:15 ` [PATCH 2/2] usbip: Correct format specifier for seqnum from %d to %u Xiong Nandi
2025-01-02 22:09   ` Shuah Khan
2025-01-03 15:25     ` xndcn
2025-01-15 21:14   ` Shuah Khan

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