Commit f7e30f01 authored Apr 12, 2017 by Matthias Kaehlcke Committed by Thomas Gleixner Apr 14, 2017

cpumask: Add helper cpumask_available()



With CONFIG_CPUMASK_OFFSTACK=y cpumask_var_t is a struct cpumask
pointer, otherwise a struct cpumask array with a single element.

Some code dealing with cpumasks needs to validate that a cpumask_var_t
is not a NULL pointer when CONFIG_CPUMASK_OFFSTACK=y. This is typically
done by performing the check always, regardless of the underlying type
of cpumask_var_t. This works in both cases, however clang raises a
warning like this when 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]

Add the inline helper cpumask_available() which only performs the
pointer check if CONFIG_CPUMASK_OFFSTACK=y.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Cc: Grant Grundler <grundler@chromium.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Greg Hackmann <ghackmann@google.com>
Cc: Michael Davidson <md@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20170412182030.83657-1-mka@chromium.org


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

parent 45e52022

include/linux/cpumask.h

+10 −0

Original line number	Diff line number	Diff line
		@@ -667,6 +667,11 @@ void alloc_bootmem_cpumask_var(cpumask_var_t *mask);
		void free_cpumask_var(cpumask_var_t mask);
		void free_bootmem_cpumask_var(cpumask_var_t mask);

		static inline bool cpumask_available(cpumask_var_t mask)
		{
		return mask != NULL;
		}

		#else
		typedef struct cpumask cpumask_var_t[1];

		@@ -708,6 +713,11 @@ static inline void free_cpumask_var(cpumask_var_t mask)
		static inline void free_bootmem_cpumask_var(cpumask_var_t mask)
		{
		}

		static inline bool cpumask_available(cpumask_var_t mask)
		{
		return true;
		}
		#endif /* CONFIG_CPUMASK_OFFSTACK */

		/* It's common to want to use cpu_all_mask in struct member initializers,

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