4.4-stable review patch. If anyone has any objections, please let me know.
------------------ From: Matthias Kaehlcke <m...@chromium.org> commit f7e30f01a9e221067bb4b579e3cfc25cd2617467 upstream. 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 <m...@chromium.org> Cc: Grant Grundler <grund...@chromium.org> Cc: Rusty Russell <ru...@rustcorp.com.au> Cc: Greg Hackmann <ghackm...@google.com> Cc: Michael Davidson <m...@google.com> Cc: Andrew Morton <a...@linux-foundation.org> Link: http://lkml.kernel.org/r/20170412182030.83657-1-...@chromium.org Signed-off-by: Thomas Gleixner <t...@linutronix.de> Cc: Nathan Chancellor <natechancel...@gmail.com> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- include/linux/cpumask.h | 10 ++++++++++ 1 file changed, 10 insertions(+) --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -661,6 +661,11 @@ void alloc_bootmem_cpumask_var(cpumask_v 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]; @@ -701,6 +706,11 @@ static inline void free_cpumask_var(cpum 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,
