Re: [patch 2/2] alarm unsigned signed conversion fixup

[Andrew Morton <akpm@osdl.org>]

Thomas Gleixner <tglx@linutronix.de> wrote:
>
> On Sat, 2006-03-18 at 12:12 -0800, Andrew Morton wrote:
> > Thomas Gleixner <tglx@linutronix.de> wrote:
> > >
> > > alarm() calls the kernel with an unsigend int timeout in seconds.
> > >  The value is converted to a timeval which is used to setup the
> > >  itimer. The tv_sec field of the timeval is a long, which causes
> > >  the timeout to be negative on 32 bit machines if seconds > INT_MAX.
> > >  Also this was silently caught before the hrtimer merge. 
> > >  To avoid fixups all over the place the duplicated sys_alarm code 
> > >  is moved to itimer.c.
> > 
> > It's not clear what you mean by this.   What does "silently caught" mean?
> > 
> > I _think_ you mean "a negative tv_sec gets treated in a random fashion, but
> > with my preceding patch it will incorrectly get -EINVAL, so fix things to
> > accept this large tv_sec".  Or something else.
> > 
> > Please clarify.
> > 
> > What happens if change sys_setitimer() to normalise the incoming timeval as
> > I suggested?  I guess that doesn't affect this..
> 
> No, because a negative value does not become positive by normalizing.
> Well except you build a normalizing function which converts negative
> values to INT_MAX.
> 

I just don't know what this patch does, sorry.

I could go read it and work that out, but am lazy.

Can we start again?