mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-06 19:07:52 +00:00
usb: gadget: u_serial: Avoid spinlock recursion in __gs_console_push
When serial console over USB is enabled, gs_console_connect queues gs_console_work, where it acquires the spinlock and queues the usb request, and this request goes to gadget layer. Now consider a situation where gadget layer prints something to dmesg, this will eventually call gs_console_write() which requires cons->lock. And this causes spinlock recursion. Avoid this by excluding usb_ep_queue from the spinlock. spin_lock_irqsave //needs cons->lock gs_console_write . . _printk __warn_printk dev_warn/pr_err . . [USB Gadget Layer] . . usb_ep_queue gs_console_work __gs_console_push // acquires cons->lock process_one_work Signed-off-by: Prashanth K <quic_prashk@quicinc.com> Link: https://lore.kernel.org/r/1683638872-6885-1-git-send-email-quic_prashk@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
2f6ecb89fe
commit
e599046994
1 changed files with 3 additions and 0 deletions
|
@ -916,8 +916,11 @@ static void __gs_console_push(struct gs_console *cons)
|
||||||
}
|
}
|
||||||
|
|
||||||
req->length = size;
|
req->length = size;
|
||||||
|
|
||||||
|
spin_unlock_irq(&cons->lock);
|
||||||
if (usb_ep_queue(ep, req, GFP_ATOMIC))
|
if (usb_ep_queue(ep, req, GFP_ATOMIC))
|
||||||
req->length = 0;
|
req->length = 0;
|
||||||
|
spin_lock_irq(&cons->lock);
|
||||||
}
|
}
|
||||||
|
|
||||||
static void gs_console_work(struct work_struct *work)
|
static void gs_console_work(struct work_struct *work)
|
||||||
|
|
Loading…
Reference in a new issue