Hi Arnd, On Thu, Jan 02, 2014 at 01:07:39PM +0100, Arnd Bergmann wrote: > We really want to kill off interruptible_sleep_on, which is defined > in a way that is always racy. There are four usb-serial drivers using > it to implement their tiocmiwait() functions, which is defined in > a way that always has a race when called from user space. > > This patch changes the four drivers in the same way to use an open-coded > prepare_to_wait/finish_wait loop to get rid of the deprecated function > call, but it does not address the fundamental race. > > This particular method of implementing it was chosen because it is > least invasive, a better but more invasive alternative would be > to use usb_serial_generic_tiocmiwait, which is something I did not > dare try without access to hardware. I'd prefer to just fix the race once and for all. These four drivers have been on my todo list since I converted the other usb-serial drivers about a year ago. In fact, I posted a fix for f81232 last week, and I've had a fix for pl2303 brewing as part of larger series for quite some time. I'll post a conversion series to linux-usb shortly and make sure to keep you CC:ed on the sleep_on-killing patches. Thanks, Johan > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> > Cc: Johan Hovold <jhovold@xxxxxxxxx> > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > Cc: linux-usb@xxxxxxxxxxxxxxx > --- > drivers/usb/serial/ch341.c | 29 ++++++++++++++++-------- > drivers/usb/serial/cypress_m8.c | 49 ++++++++++++++++++++++++++--------------- > drivers/usb/serial/f81232.c | 29 ++++++++++++++++-------- > drivers/usb/serial/pl2303.c | 29 ++++++++++++++++-------- > 4 files changed, 91 insertions(+), 45 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
