This is a note to let you know that I've just added the patch titled

cpumask: Add helper cpumask_available()

to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: cpumask-add-helper-cpumask_available.patch and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From f7e30f01a9e221067bb4b579e3cfc25cd2617467 Mon Sep 17 00:00:00 2001

From: Matthias Kaehlcke mka@chromium.org Date: Wed, 12 Apr 2017 11:20:29 -0700 Subject: cpumask: Add helper cpumask_available()

From: Matthias Kaehlcke mka@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 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 Cc: Nathan Chancellor natechancellor@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- include/linux/cpumask.h | 10 ++++++++++ 1 file changed, 10 insertions(+)

--- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -680,6 +680,11 @@ 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];

@@ -720,6 +725,11 @@ 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,

Patches currently in stable-queue which might be from mka@chromium.org are

queue-4.9/dm-ioctl-remove-double-parentheses.patch queue-4.9/genirq-use-cpumask_available-for-check-of-cpumask-variable.patch queue-4.9/fs-compat-remove-warning-from-compatible_ioctl.patch queue-4.9/selinux-remove-unnecessary-check-of-array-base-in-selinux_set_mapping.patch queue-4.9/pci-make-pci_rom_address_mask-a-32-bit-constant.patch queue-4.9/cpumask-add-helper-cpumask_available.patch