2020-07-06 08:03:19

by Zhang, Qiang

Subject: [PATCH v2] usb: gadget: function: fix missing spinlock in f_uac1_legacy

From: Zhang Qiang <[email protected]>

Add a missing spinlock protection to the add operation of the "audio->play_queue"
in "f_audio_out_ep_complete" function.

Signed-off-by: Zhang Qiang <[email protected]>
---
v1->v2:
Add changelog text.

drivers/usb/gadget/function/f_uac1_legacy.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/usb/gadget/function/f_uac1_legacy.c b/drivers/usb/gadget/function/f_uac1_legacy.c
index 349deae7cabd..e2d7f69128a0 100644
--- a/drivers/usb/gadget/function/f_uac1_legacy.c
+++ b/drivers/usb/gadget/function/f_uac1_legacy.c
@@ -336,7 +336,9 @@ static int f_audio_out_ep_complete(struct usb_ep *ep, struct usb_request *req)

/* Copy buffer is full, add it to the play_queue */
if (audio_buf_size - copy_buf->actual < req->actual) {
+ spin_lock_irq(&audio->lock);
list_add_tail(&copy_buf->list, &audio->play_queue);
+ spin_unlock_irq(&audio->lock);
schedule_work(&audio->playback_work);
copy_buf = f_audio_buffer_alloc(audio_buf_size);
if (IS_ERR(copy_buf))
--
2.24.1

2020-07-06 10:34:08

by Greg Kroah-Hartman

Subject: Re: [PATCH v2] usb: gadget: function: fix missing spinlock in f_uac1_legacy

On Sun, Jul 05, 2020 at 02:16:16PM +0800, [email protected] wrote:
> From: Zhang Qiang <[email protected]>
>
> Add a missing spinlock protection to the add operation of the "audio->play_queue"
> in "f_audio_out_ep_complete" function.

That says _what_ you did, but not _why_ you did that. Why is a lock
needed here? What does this protect?

What kernel commit does this "fix"? Put that in the "Fixes:" line, and
probably you need a "cc: stable" in that area too, right?

thanks,

greg k-h

2020-07-06 14:30:57

by Zhang, Qiang

Subject: 回复: [PATCH v2] usb: gadget: function: fix m issing spinlock in f_uac1_legacy

Thanks for your suggestin Greg KH
I think there is not need fix tags. I will resend.

thanks,
Zhang Qiang

________________________________________
??????: Greg KH <[email protected]>
????ʱ??: 2020??7??6?? 18:31
?ռ???: Zhang, Qiang
????: [email protected]; [email protected]; [email protected]; [email protected]
????: Re: [PATCH v2] usb: gadget: function: fix missing spinlock in f_uac1_legacy

On Sun, Jul 05, 2020 at 02:16:16PM +0800, [email protected] wrote:
> From: Zhang Qiang <[email protected]>
>
> Add a missing spinlock protection to the add operation of the "audio->play_queue"
> in "f_audio_out_ep_complete" function.

That says _what_ you did, but not _why_ you did that. Why is a lock
needed here? What does this protect?

What kernel commit does this "fix"? Put that in the "Fixes:" line, and
probably you need a "cc: stable" in that area too, right?

thanks,

greg k-h