alistair23-linux/mm
zijun_hu 3ca45a46f8 percpu: ensure the requested alignment is power of two
The percpu allocator expectedly assumes that the requested alignment
is power of two but hasn't been veryfing the input.  If the specified
alignment isn't power of two, the allocator can malfunction.  Add the
sanity check.

The following is detailed analysis of the effects of alignments which
aren't power of two.

 The alignment must be a even at least since the LSB of a chunk->map
 element is used as free/in-use flag of a area; besides, the alignment
 must be a power of 2 too since ALIGN() doesn't work well for other
 alignment always but is adopted by pcpu_fit_in_area().  IOW, the
 current allocator only works well for a power of 2 aligned area
 allocation.

 See below opposite example for why an odd alignment doesn't work.
 Let's assume area [16, 36) is free but its previous one is in-use, we
 want to allocate a @size == 8 and @align == 7 area.  The larger area
 [16, 36) is split to three areas [16, 21), [21, 29), [29, 36)
 eventually.  However, due to the usage for a chunk->map element, the
 actual offset of the aim area [21, 29) is 21 but is recorded in
 relevant element as 20; moreover, the residual tail free area [29,
 36) is mistook as in-use and is lost silently

 Unlike macro roundup(), ALIGN(x, a) doesn't work if @a isn't a power
 of 2 for example, roundup(10, 6) == 12 but ALIGN(10, 6) == 10, and
 the latter result isn't desired obviously.

tj: Code style and patch description updates.

Signed-off-by: zijun_hu <zijun_hu@htc.com>
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2016-10-19 13:53:02 -04:00
..
kasan kasan: remove the unnecessary WARN_ONCE from quarantine.c 2016-08-11 16:58:14 -07:00
backing-dev.c block: fix bdi vs gendisk lifetime mismatch 2016-08-04 14:19:16 -06:00
balloon_compaction.c mm: balloon: use general non-lru movable page feature 2016-07-26 16:19:19 -07:00
bootmem.c mm: kmemleak: avoid using __va() on addresses that don't have a lowmem mapping 2016-10-11 15:06:33 -07:00
cleancache.c
cma.c mm: kmemleak: avoid using __va() on addresses that don't have a lowmem mapping 2016-10-11 15:06:33 -07:00
cma.h
cma_debug.c
compaction.c mm, compaction: restrict fragindex to costly orders 2016-10-07 18:46:29 -07:00
debug.c mm: clarify why we avoid page_mapcount() for slab pages in dump_page() 2016-10-07 18:46:29 -07:00
debug_page_ref.c
dmapool.c
early_ioremap.c
fadvise.c mm/fadvise.c: do not discard partial pages with POSIX_FADV_DONTNEED 2016-06-09 14:23:11 -07:00
failslab.c
filemap.c Merge branch 'work.splice_read' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 13:38:49 -07:00
frame_vector.c
frontswap.c mm, frontswap: convert frontswap_enabled to static key 2016-07-26 16:19:19 -07:00
gup.c - ARM: GICv3 ITS emulation and various fixes. Removal of the old 2016-08-02 16:11:27 -04:00
highmem.c
huge_memory.c mm: vm_page_prot: update with WRITE_ONCE/READ_ONCE 2016-10-07 18:46:29 -07:00
hugetlb.c mm: remove unnecessary condition in remove_inode_hugepages 2016-10-07 18:46:29 -07:00
hugetlb_cgroup.c
hwpoison-inject.c
init-mm.c
internal.h mm, compaction: make full priority ignore pageblock suitability 2016-10-07 18:46:29 -07:00
interval_tree.c
Kconfig mm: clarify COMPACTION Kconfig text 2016-08-26 17:39:35 -07:00
Kconfig.debug PM / Hibernate: allow hibernation with PAGE_POISONING_ZERO 2016-09-13 02:35:27 +02:00
khugepaged.c mm, thp: fix leaking mapped pte in __collapse_huge_page_swapin() 2016-09-19 15:36:16 -07:00
kmemcheck.c
kmemleak-test.c
kmemleak.c mm: kmemleak: avoid using __va() on addresses that don't have a lowmem mapping 2016-10-11 15:06:33 -07:00
ksm.c mm,ksm: add __GFP_HIGH to the allocation in alloc_stable_node() 2016-10-07 18:46:29 -07:00
list_lru.c
maccess.c
madvise.c
Makefile Disable the __builtin_return_address() warning globally after all 2016-10-12 10:23:41 -07:00
memblock.c mm: kmemleak: avoid using __va() on addresses that don't have a lowmem mapping 2016-10-11 15:06:33 -07:00
memcontrol.c mm: memcontrol: consolidate cgroup socket tracking 2016-10-07 18:46:29 -07:00
memory-failure.c mm: hwpoison: remove incorrect comments 2016-07-28 16:07:41 -07:00
memory.c mm: fix cache mode tracking in vm_insert_mixed() 2016-10-07 18:46:28 -07:00
memory_hotplug.c mm/hugetlb: check for reserved hugepages during memory offline 2016-10-07 18:46:29 -07:00
mempolicy.c mm: use zonelist name instead of using hardcoded index 2016-10-07 18:46:28 -07:00
mempool.c Revert "mm, mempool: only set __GFP_NOMEMALLOC if there are free elements" 2016-07-28 16:07:41 -07:00
memtest.c
migrate.c mm: vm_page_prot: update with WRITE_ONCE/READ_ONCE 2016-10-07 18:46:29 -07:00
mincore.c mm, swap: use offset of swap entry as key of swap cache 2016-10-07 18:46:28 -07:00
mlock.c mm: mlock: avoid increase mm->locked_vm on mlock() when already mlock2(,MLOCK_ONFAULT) 2016-10-07 18:46:28 -07:00
mm_init.c
mmap.c mm: vma_merge: correct false positive from __vma_unlink->validate_mm_rb 2016-10-07 18:46:29 -07:00
mmu_context.c
mmu_notifier.c
mmzone.c
mprotect.c Merge branch 'mm-pkeys-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-10-10 11:01:51 -07:00
mremap.c mm: thp: check pmd_trans_unstable() after split_huge_pmd() 2016-07-26 16:19:19 -07:00
msync.c
nobootmem.c mm: kmemleak: avoid using __va() on addresses that don't have a lowmem mapping 2016-10-11 15:06:33 -07:00
nommu.c mm: introduce fault_env 2016-07-26 16:19:19 -07:00
oom_kill.c oom: print nodemask in the oom report 2016-10-07 18:46:29 -07:00
page-writeback.c mm: don't use radix tree writeback tags for pages in swap cache 2016-10-07 18:46:28 -07:00
page_alloc.c This adds a new gcc plugin named "latent_entropy". It is designed to 2016-10-15 10:03:15 -07:00
page_counter.c
page_ext.c mm/page_ext: support extra space allocation by page_ext user 2016-10-07 18:46:27 -07:00
page_idle.c mm, vmscan: move lru_lock to the node 2016-07-28 16:07:41 -07:00
page_io.c mm/page_io.c: replace some BUG_ON()s with VM_BUG_ON_PAGE() 2016-10-07 18:46:29 -07:00
page_isolation.c mm/page_isolation: fix typo: "paes" -> "pages" 2016-10-07 18:46:29 -07:00
page_owner.c mm/page_owner: don't define fields on struct page_ext by hard-coding 2016-10-07 18:46:27 -07:00
page_poison.c
pagewalk.c
percpu-km.c
percpu-vm.c
percpu.c percpu: ensure the requested alignment is power of two 2016-10-19 13:53:02 -04:00
pgtable-generic.c
process_vm_access.c
quicklist.c
readahead.c mm: silently skip readahead for DAX inodes 2016-08-26 17:39:35 -07:00
rmap.c rmap: fix compound check logic in page_remove_file_rmap 2016-08-10 16:40:56 -07:00
shmem.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
slab.c slab: Convert to hotplug state machine 2016-09-06 18:30:20 +02:00
slab.h mm, kasan: switch SLUB to stackdepot, enable memory quarantine for SLUB 2016-07-28 16:07:41 -07:00
slab_common.c mm: charge/uncharge kmemcg from generic page allocator paths 2016-07-26 16:19:19 -07:00
slob.c
slub.c slub: Convert to hotplug state machine 2016-09-06 18:30:20 +02:00
sparse-vmemmap.c treewide: replace obsolete _refok by __ref 2016-08-02 17:31:41 -04:00
sparse.c treewide: replace obsolete _refok by __ref 2016-08-02 17:31:41 -04:00
swap.c thp: reduce usage of huge zero page's atomic counter 2016-10-07 18:46:28 -07:00
swap_cgroup.c
swap_state.c mm, swap: use offset of swap entry as key of swap cache 2016-10-07 18:46:28 -07:00
swapfile.c mm, swap: use offset of swap entry as key of swap cache 2016-10-07 18:46:28 -07:00
truncate.c truncate: handle file thp 2016-07-26 16:19:19 -07:00
usercopy.c mm: usercopy: Check for module addresses 2016-09-20 16:07:39 -07:00
userfaultfd.c
util.c mm: move most file-based accounting to the node 2016-07-28 16:07:41 -07:00
vmacache.c mm: unrig VMA cache hit ratio 2016-10-07 18:46:27 -07:00
vmalloc.c mm: consolidate warn_alloc_failed users 2016-10-07 18:46:29 -07:00
vmpressure.c
vmscan.c mm: use zonelist name instead of using hardcoded index 2016-10-07 18:46:28 -07:00
vmstat.c seq/proc: modify seq_put_decimal_[u]ll to take a const char *, not char 2016-10-07 18:46:30 -07:00
workingset.c mm: workingset: fix crash in shadow node shrinker caused by replace_page_cache_page() 2016-09-30 15:26:52 -07:00
z3fold.c
zbud.c
zpool.c
zsmalloc.c zsmalloc: Delete an unnecessary check before the function call "iput" 2016-07-28 16:07:41 -07:00
zswap.c