Re: [PATCH 01/16] CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONS: set if CPUMASK_OFFSTACK.

From: Paul Bolle
Date: Mon Mar 02 2015 - 07:34:17 EST


On Mon, 2015-03-02 at 22:05 +1030, Rusty Russell wrote:
> Using these functions with offstack cpus is unsafe. They use all NR_CPUS
> bits, unstead of nr_cpumask_bits.
>
> In particular, lustre (in staging) used cpus_ and that caused a bug.
>
> Reported-by: Oleg Drokin <green@xxxxxxxxxxxxxx>
> Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
> ---
> lib/Kconfig | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/lib/Kconfig b/lib/Kconfig
> index 87da53bb1fef..722427805220 100644
> --- a/lib/Kconfig
> +++ b/lib/Kconfig
> @@ -398,8 +398,8 @@ config CPUMASK_OFFSTACK
> stack overflow.
>
> config DISABLE_OBSOLETE_CPUMASK_FUNCTIONS
> - bool "Disable obsolete cpumask functions" if DEBUG_PER_CPU_MAPS
> - depends on BROKEN
> + bool
> + depends on CPUMASK_OFFSTACK

This removes the "prompt" from this symbol's entry. And nothing selects
it either (not in next-20150302 nor in this series). So I think this
just disables this Kconfig symbol entirely. Ie, it can't be set even if
CPUMAK_OFFSTACK is set.

Should this entry perhaps be using
def_bool y

instead?

> config CPU_RMAP
> bool

Thanks,


Paul Bolle

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