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| author | Prashanth K <[email protected]> | 2023-05-09 13:27:52 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <[email protected]> | 2023-05-29 14:22:47 +0000 |
| commit | e5990469943c711cb00bfde6338d2add6c6d0bfe (patch) | |
| tree | 3a2d0733d82f6b3ac979946d1c3dc3d5d267b228 /drivers/usb/cdns3/cdns3-starfive.c | |
| parent | usb: gadget: u_serial: Add null pointer check in gserial_suspend (diff) | |
| download | kernel-e5990469943c711cb00bfde6338d2add6c6d0bfe.tar.gz kernel-e5990469943c711cb00bfde6338d2add6c6d0bfe.zip | |
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 <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Diffstat (limited to 'drivers/usb/cdns3/cdns3-starfive.c')
0 files changed, 0 insertions, 0 deletions