CVS commit: src/sys/dev/usb

["Taylor R Campbell" <riastradh%netbsd.org@localhost>]

Module Name:    src
Committed By:   riastradh
Date:           Sun Mar 13 11:28:42 UTC 2022

Modified Files:
        src/sys/dev/usb: usb_subr.c usbdi.c usbdivar.h

Log Message:
usbdi(9): Assert no concurrent aborts on a single pipe.

It is a driver bug to try to abort a pipe at the same time in two
different threads.

HCI drivers may release the bus lock to sleep in upm_abort while
waiting for the hardware to acknowledge an abort, so it won't try to,
e.g., scribble over a DMA buffer in the xfer that we've recycled
after usbd_abort_pipe returns.

If this happens, a concurrent usbd_abort_pipe might try to apply
upm_abort to the same xfer, which HCI drivers are not prepared for
and may wreak havoc.

To avoid this, allow only one usbd_abort_pipe in flight at any given
time.


To generate a diff of this commit:
cvs rdiff -u -r1.270 -r1.271 src/sys/dev/usb/usb_subr.c
cvs rdiff -u -r1.234 -r1.235 src/sys/dev/usb/usbdi.c
cvs rdiff -u -r1.135 -r1.136 src/sys/dev/usb/usbdivar.h

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.