On Mon, Jun 19, 2017 at 05:53:34PM +0300, Dmitry Safonov wrote:
> On 05/24/2017 05:51 PM, Dmitry Safonov wrote:
> > binder_mmap() protected proc->buffer from concurrent changes.
> > It was introduced with commit bd1eff9741af ("Staging: android: binder:
> > Fix crashes when sharing a binder file between processes").
> >
> > The commit fixed such races alike:
> >
> > task1
> > =====
> > fd = open("/dev/binder",..)
> > fork()
> > ---------------------------------------->task2
> > | =====
> > mmap(fd) mmap(fd)
> >
> > Afterwards the situation was changed with the commit a79f41ed9786
> > ("binder: don't allow mmap() by process other than proc->tsk").
> > That commit prohibited mmap'ing of fd, that was opened by some
> > other task.
> > That restriction has made locking in binder_mmap() unnecessary.
> >
> > Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
> > Cc: "Arve Hjønnevåg" <arve@xxxxxxxxxxx>
> > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> > Cc: Riley Andrews <riandrews@xxxxxxxxxxx>
> > Cc: devel@xxxxxxxxxxxxxxxxxxxx
> > Cc: Android Kernel Team <kernel-team@xxxxxxxxxxx>
> > Signed-off-by: Dmitry Safonov <dsafonov@xxxxxxxxxxxxx>
> > ---
> > drivers/android/binder.c | 5 -----
> > 1 file changed, 5 deletions(-)
>
> Ping?
The "break up the binder lock" patches should have now made this
obsolete, right? If not, can you please rebase it on my
char-misc-testing tree and resend?
thanks,
greg k-h
_______________________________________________
devel mailing list
devel@xxxxxxxxxxxxxxxxxxxxxx
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
