Re: [PATCH tip/core/rcu 9/9] rcu: Suppress levelspread uninitialized messages

[Paul E. McKenney]

On Thu, Oct 03, 2019 at 10:53:03AM +0200, Geert Uytterhoeven wrote:
> Hi Paul,
> 
> On Thu, Oct 3, 2019 at 3:49 AM <paulmck@xxxxxxxxxx> wrote:
> > From: "Paul E. McKenney" <paulmck@xxxxxxxxxx>
> >
> > New tools bring new warnings, and with v5.3 comes:
> 
> According to the kisskb build logs, it happens with gcc 4.6.3 only ;-)
> 
> > kernel/rcu/srcutree.c: warning: 'levelspread[<U aa0>]' may be used uninitialized in this function [-Wuninitialized]:  => 121:34
> >
> > This commit suppresses this warning by initializing the full array
> > to INT_MIN, which will result in failures should any out-of-bounds
> > references appear.
> >
> > Reported-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> > Reported-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> > Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
> 
> Thanks for your patch!
> 
> Reviewed-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> (for the initialization loop, not for the actual INT_MIN value)

Applied, thank you!

> Unfortunately I don't have a gcc-4.6.3 Linux cross-compiler anymore.
> I tried with msp430-gcc-4.6.3 and some hackery to get it to compile,
> but that didn't let me reproduce the warning.

OK, please let me know when gcc-4.6.3 is old enough that this patch
should be reverted.  Or just submit the revert at that point, as the
case may be.  ;-)

							Thanx, Paul