The patch titled Subject: cpumask: use nr_cpumask_bits for parsing functions has been removed from the -mm tree. Its filename was cpumask-use-nr_cpumask_bits-for-parsing-functions.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Tejun Heo <tj@xxxxxxxxxx> Subject: cpumask: use nr_cpumask_bits for parsing functions 513e3d2d11c9 ("cpumask: always use nr_cpu_ids in formatting and parsing functions") converted both cpumask printing and parsing functions to use nr_cpu_ids instead of nr_cpumask_bits. While this was okay for the printing functions as it just picked one of the two output formats that we were alternating between depending on a kernel config, doing the same for parsing wasn't okay. nr_cpumask_bits can be either nr_cpu_ids or NR_CPUS. We can always use nr_cpu_ids but that is a variable while NR_CPUS is a constant, so it can be more efficient to use NR_CPUS when we can get away with it. Converting the printing functions to nr_cpu_ids makes sense because it affects how the masks get presented to userspace and doesn't break anything; however, using nr_cpu_ids for parsing functions can incorrectly leave the higher bits uninitialized while reading in these masks from userland. As all testing and comparison functions use nr_cpumask_bits which can be larger than nr_cpu_ids, the parsed cpumasks can erroneously yield false negative results. This made the taskstats interface incorrectly return -EINVAL even when the inputs were correct. Fix it by restoring the parse functions to use nr_cpumask_bits instead of nr_cpu_ids. Link: http://lkml.kernel.org/r/20170206182442.GB31078@xxxxxxxxxxxxxxx Fixes: 513e3d2d11c9 ("cpumask: always use nr_cpu_ids in formatting and parsing functions") Signed-off-by: Tejun Heo <tj@xxxxxxxxxx> Reported-by: Martin Steigerwald <martin.steigerwald@xxxxxxxxx> Debugged-by: Ben Hutchings <ben.hutchings@xxxxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> [4.0+] Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/cpumask.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff -puN include/linux/cpumask.h~cpumask-use-nr_cpumask_bits-for-parsing-functions include/linux/cpumask.h --- a/include/linux/cpumask.h~cpumask-use-nr_cpumask_bits-for-parsing-functions +++ a/include/linux/cpumask.h @@ -560,7 +560,7 @@ static inline void cpumask_copy(struct c static inline int cpumask_parse_user(const char __user *buf, int len, struct cpumask *dstp) { - return bitmap_parse_user(buf, len, cpumask_bits(dstp), nr_cpu_ids); + return bitmap_parse_user(buf, len, cpumask_bits(dstp), nr_cpumask_bits); } /** @@ -575,7 +575,7 @@ static inline int cpumask_parselist_user struct cpumask *dstp) { return bitmap_parselist_user(buf, len, cpumask_bits(dstp), - nr_cpu_ids); + nr_cpumask_bits); } /** @@ -590,7 +590,7 @@ static inline int cpumask_parse(const ch char *nl = strchr(buf, '\n'); unsigned int len = nl ? (unsigned int)(nl - buf) : strlen(buf); - return bitmap_parse(buf, len, cpumask_bits(dstp), nr_cpu_ids); + return bitmap_parse(buf, len, cpumask_bits(dstp), nr_cpumask_bits); } /** @@ -602,7 +602,7 @@ static inline int cpumask_parse(const ch */ static inline int cpulist_parse(const char *buf, struct cpumask *dstp) { - return bitmap_parselist(buf, cpumask_bits(dstp), nr_cpu_ids); + return bitmap_parselist(buf, cpumask_bits(dstp), nr_cpumask_bits); } /** _ Patches currently in -mm which might be from tj@xxxxxxxxxx are revert-slub-move-synchronize_sched-out-of-slab_mutex-on-shrink.patch slub-separate-out-sysfs_slab_release-from-sysfs_slab_remove.patch slab-remove-synchronous-rcu_barrier-call-in-memcg-cache-release-path.patch slab-reorganize-memcg_cache_params.patch slab-link-memcg-kmem_caches-on-their-associated-memory-cgroup.patch slab-implement-slab_root_caches-list.patch slab-introduce-__kmemcg_cache_deactivate.patch slab-remove-synchronous-synchronize_sched-from-memcg-cache-deactivation-path.patch slab-remove-slub-sysfs-interface-files-early-for-empty-memcg-caches.patch slab-use-memcg_kmem_cache_wq-for-slab-destruction-operations.patch slub-make-sysfs-directories-for-memcg-sub-caches-optional.patch