Re: [PATCH] kernel/irq: Limit validation of cpumask_var_t to CONFIG_CPUMASK_OFFSTACK=y

[Thomas Gleixner]

On Tue, 11 Apr 2017, Matthias Kaehlcke wrote:
> With CONFIG_CPUMASK_OFFSTACK=y cpumask_var_t is a struct cpumask
> pointer, otherwise a struct cpumask array with a single element.
> 
> irq_thread_check_affinity() validates the cpumask_var_t field in the
> interrupt descriptor by checking if it is not NULL. This works for
> both CONFIG_CPUMASK_OFFSTACK=y/n, however clang raises the following
> warning with CONFIG_CPUMASK_OFFSTACK=n:
> 
> kernel/irq/manage.c:839:28: error: address of array
> 'desc->irq_common_data.affinity' will always evaluate to 'true'
> [-Werror,-Wpointer-bool-conversion]
> 
> To get rid of the warning only validate the cpumask_var_t field when
> CONFIG_CPUMASK_OFFSTACK=y.

This ifdeffery is horrible. Can you please create a helper inline
cpumask_available() or something like that which hides this in a header
file. The irq code is probably not the only place which does this.

Thanks,

	tglx