Messages in this thread | | | Date | Thu, 15 Mar 2012 15:40:18 +0000 | From | Alan Cox <> | Subject | Re: [PATCH] tty: hold lock across tty buffer finding and buffer filling |
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On Thu, 15 Mar 2012 10:14:07 +0000 "Du, Alek" <alek.du@intel.com> wrote:
> Alan, > > I agree with you for the case of multiple writers to the tty buffer. > > But there is another case that cause kernel hang: driver is writing data to tty, while app shutdown the port or flush through IOCTL. The buf.tail is set to NULL, here is the log: > > > <1>[ 4713.451954] BUG: unable to handle kernel NULL pointer dereference at > 00000004 > <1>[ 4713.452424] IP: [<c14ff59c>] tty_insert_flip_string_fixed_flag+0x4c/0x90
Ouch.. yes that makes sense.
Alan
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