Re: [PATCH v2] drivers/net/usb/hso.c: prevent reading uninitializedmemory

From: Alan Cox
Date: Thu Sep 16 2010 - 13:26:32 EST


On Thu, 16 Sep 2010 12:52:40 -0400
Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:

> On Thu, 2010-09-16 at 18:07 +0100, Alan Cox wrote:
> > ->tiocmget;
> > > >
> > > > + memset(&icount, 0, sizeof(struct serial_icounter_struct));
> > > > +
> > >
> > > Move the above to after the spinlocks.
> >
> > Why - its a local variable ?
> >
> > Easier to write
> >
> > struct serial_icounter_struct icount = { 0 };
> >
> > though
>
> True, but if we want to micro-optimize, moving it after the spinlocks
> means we do no zero initialization in the tiocmget == 0. Although gcc
> may be smart enough to realize that too.

If you want to micro-optimise it you can enumerate the cases that
tiocmget can be NULL in that driver..
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