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Commit Graph

15341 Commits

Author SHA1 Message Date
Wei Yang
a1ddc2e825 mm/hugetlb: remove VM_BUG_ON(!nrg) in get_file_region_entry_from_cache()
We are sure to get a valid file_region, otherwise the
VM_BUG_ON(resv->region_cache_count <= 0) at the very beginning would be
triggered.

Let's remove the redundant one.

Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Link: https://lkml.kernel.org/r/20200831022351.20916-3-richard.weiyang@linux.alibaba.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:34 -07:00
Wei Yang
7db5e7b67e mm/hugetlb: not necessary to coalesce regions recursively
Patch series "mm/hugetlb: code refine and simplification", v4.

Following are some cleanups for hugetlb.  Simple testing with
tools/testing/selftests/vm/map_hugetlb passes.

This patch (of 7):

Per my understanding, we keep the regions ordered and would always
coalesce regions properly.  So the task to keep this property is just to
coalesce its neighbour.

Let's simplify this.

Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Link: https://lkml.kernel.org/r/20200901014636.29737-1-richard.weiyang@linux.alibaba.com
Link: https://lkml.kernel.org/r/20200831022351.20916-1-richard.weiyang@linux.alibaba.com
Link: https://lkml.kernel.org/r/20200831022351.20916-2-richard.weiyang@linux.alibaba.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:34 -07:00
Baoquan He
d79d176a30 mm/hugetlb.c: remove the unnecessary non_swap_entry()
If a swap entry tests positive for either is_[migration|hwpoison]_entry(),
then its swap_type() is among SWP_MIGRATION_READ, SWP_MIGRATION_WRITE and
SWP_HWPOISON.  All these types >= MAX_SWAPFILES, exactly what is asserted
with non_swap_entry().

So the checking non_swap_entry() in is_hugetlb_entry_migration() and
is_hugetlb_entry_hwpoisoned() is redundant.

Let's remove it to optimize code.

Signed-off-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lkml.kernel.org/r/20200723032248.24772-3-bhe@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:33 -07:00
Baoquan He
3e5c36007e mm/hugetlb.c: make is_hugetlb_entry_hwpoisoned return bool
Patch series "mm/hugetlb: Small cleanup and improvement", v2.

This patch (of 3):

Just like its neighbour is_hugetlb_entry_migration() has done.

Signed-off-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lkml.kernel.org/r/20200723032248.24772-1-bhe@redhat.com
Link: https://lkml.kernel.org/r/20200723032248.24772-2-bhe@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:33 -07:00
Matthew Wilcox (Oracle)
e320d3012d mm/page_alloc.c: fix freeing non-compound pages
Here is a very rare race which leaks memory:

Page P0 is allocated to the page cache.  Page P1 is free.

Thread A                Thread B                Thread C
find_get_entry():
xas_load() returns P0
						Removes P0 from page cache
						P0 finds its buddy P1
			alloc_pages(GFP_KERNEL, 1) returns P0
			P0 has refcount 1
page_cache_get_speculative(P0)
P0 has refcount 2
			__free_pages(P0)
			P0 has refcount 1
put_page(P0)
P1 is not freed

Fix this by freeing all the pages in __free_pages() that won't be freed
by the call to put_page().  It's usually not a good idea to split a page,
but this is a very unlikely scenario.

Fixes: e286781d5f ("mm: speculative page references")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Nick Piggin <npiggin@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200926213919.26642-1-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:33 -07:00
Ralph Campbell
a9b576f725 mm: move call to compound_head() in release_pages()
The function is_huge_zero_page() doesn't call compound_head() to make sure
the page pointer is a head page. The call to is_huge_zero_page() in
release_pages() is made before compound_head() is called so the test would
fail if release_pages() was called with a tail page of the huge_zero_page
and put_page_testzero() would be called releasing the page.
This is unlikely to be happening in normal use or we would be seeing all
sorts of process data corruption when accessing a THP zero page.

Looking at other places where is_huge_zero_page() is called, all seem to
only pass a head page so I think the right solution is to move the call
to compound_head() in release_pages() to a point before calling
is_huge_zero_page().

Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: https://lkml.kernel.org/r/20200917173938.16420-1-rcampbell@nvidia.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:33 -07:00
Mateusz Nosek
30d8ec73e8 mmzone: clean code by removing unused macro parameter
Previously 'for_next_zone_zonelist_nodemask' macro parameter 'zlist' was
unused so this patch removes it.

Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/20200917211906.30059-1-mateusznosek0@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:33 -07:00
Yanfei Xu
2187e17b02 mm/page_alloc.c: __perform_reclaim should return 'unsigned long'
__perform_reclaim()'s single caller expects it to return 'unsigned long',
hence change its return value and a local variable to 'unsigned long'.

Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Yanfei Xu <yanfei.xu@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/20200916022138.16740-1-yanfei.xu@windriver.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:33 -07:00
Mateusz Nosek
a0622d0537 mm/page_alloc.c: clean code by merging two functions
finalise_ac() is just 'epilogue' for 'prepare_alloc_pages'.  Therefore
there is no need to keep them both so 'finalise_ac' content can be merged
into prepare_alloc_pages() code.  It would make __alloc_pages_nodemask()
cleaner when it comes to readability.

Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Rapoport <rppt@kernel.org>
Link: https://lkml.kernel.org/r/20200916110118.6537-1-mateusznosek0@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:33 -07:00
Mateusz Nosek
fdd4fa1cd9 mm/page_alloc.c: fix early params garbage value accesses
Previously in '__init early_init_on_alloc' and '__init early_init_on_free'
the return values from 'kstrtobool' were not handled properly.  That
caused potential garbage value read from variable 'bool_result'.
Introduced patch fixes error handling.

Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/20200916214125.28271-1-mateusznosek0@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:33 -07:00
Mateusz Nosek
cfb4a54191 mm/page_alloc.c: micro-optimization remove unnecessary branch
Previously flags check was separated into two separated checks with two
separated branches. In case of presence of any of two mentioned flags,
the same effect on flow occurs. Therefore checks can be merged and one
branch can be avoided.

Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/20200911092310.31136-1-mateusznosek0@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:33 -07:00
Mateusz Nosek
b630749f01 mm/page_alloc.c: clean code by removing unnecessary initialization
Previously variable 'tmp' was initialized, but was not read later before
reassigning.  So the initialization can be removed.

[akpm@linux-foundation.org: remove `tmp' altogether]

Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/20200904132422.17387-1-mateusznosek0@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:33 -07:00
Li Xinhai
6a654e36fa mm, isolation: avoid checking unmovable pages across pageblock boundary
In has_unmovable_pages(), the page parameter would not always be the first
page within a pageblock (see how the page pointer is passed in from
start_isolate_page_range() after call __first_valid_page()), so that would
cause checking unmovable pages span two pageblocks.

After this patch, the checking is enforced within one pageblock no matter
the page is first one or not, and obey the semantics of this function.

This issue is found by code inspection.

Michal said "this might lead to false negatives when an unrelated block
would cause an isolation failure".

Signed-off-by: Li Xinhai <lixinhai.lxh@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: David Hildenbrand <david@redhat.com>
Link: https://lkml.kernel.org/r/20200824065811.383266-1-lixinhai.lxh@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:33 -07:00
David Hildenbrand
1c31cb493c mm/page_isolation: cleanup set_migratetype_isolate()
Let's clean it up a bit, simplifying the exit paths.

Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Qian Cai <cai@lca.pw>
Link: http://lkml.kernel.org/r/20200816125333.7434-5-david@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:33 -07:00
David Hildenbrand
48381d7e4c mm/page_isolation: drop WARN_ON_ONCE() in set_migratetype_isolate()
Inside has_unmovable_pages(), we have a comment describing how unmovable
data could end up in ZONE_MOVABLE - via "movablecore".  Also, besides
checking if the first page in the pageblock is reserved, we don't perform
any further checks in case of ZONE_MOVABLE.

In case of memory offlining, we set REPORT_FAILURE, properly dump_page()
the page and handle the error gracefully.  alloc_contig_pages() users
currently never allocate from ZONE_MOVABLE.  E.g., hugetlb uses
alloc_contig_pages() for the allocation of gigantic pages only, which will
never end up on the MOVABLE zone (see htlb_alloc_mask()).

Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Qian Cai <cai@lca.pw>
Link: http://lkml.kernel.org/r/20200816125333.7434-4-david@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:33 -07:00
David Hildenbrand
51030a53d8 mm/page_isolation: exit early when pageblock is isolated in set_migratetype_isolate()
Right now, if we have two isolations racing on a pageblock that's in the
MOVABLE zone, we would trigger the WARN_ON_ONCE().  Let's just return
directly, simplifying error handling.

The change was introduced in commit 3d680bdf60 ("mm/page_isolation: fix
potential warning from user").  As far as I can see, we currently don't
have alloc_contig_range() users that use the ZONE_MOVABLE (anymore), so
it's currently more a cleanup and a preparation for the future than a fix.

Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Link: http://lkml.kernel.org/r/20200816125333.7434-3-david@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:33 -07:00
David Hildenbrand
c9c510dc29 mm/page_alloc: tweak comments in has_unmovable_pages()
Patch series "mm / virtio-mem: support ZONE_MOVABLE", v5.

When introducing virtio-mem, the semantics of ZONE_MOVABLE were rather
unclear, which is why we special-cased ZONE_MOVABLE such that partially
plugged blocks would never end up in ZONE_MOVABLE.

Now that the semantics are much clearer (and are documented in patch #6),
let's support partially plugged memory blocks in ZONE_MOVABLE, allowing
partially plugged memory blocks to be online to ZONE_MOVABLE and also
unplugging from such memory blocks.  This avoids surprises when onlining
of memory blocks suddenly fails, just because they are not completely
populated by virtio-mem (yet).

This is especially helpful for testing, but also paves the way for
virtio-mem optimizations, allowing more memory to get reliably unplugged.

Cleanup has_unmovable_pages() and set_migratetype_isolate(), providing
better documentation of how ZONE_MOVABLE interacts with different kind of
unmovable pages (memory offlining vs.  alloc_contig_range()).

This patch (of 6):

Let's move the split comment regarding bootmem allocations and memory
holes, especially in the context of ZONE_MOVABLE, to the PageReserved()
check.

Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Qian Cai <cai@lca.pw>
Link: http://lkml.kernel.org/r/20200816125333.7434-1-david@redhat.com
Link: http://lkml.kernel.org/r/20200816125333.7434-2-david@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:32 -07:00
David Gow
be4f1ae978 mm: kasan: do not panic if both panic_on_warn and kasan_multishot set
KASAN errors will currently trigger a panic when panic_on_warn is set.
This renders kasan_multishot useless, as further KASAN errors won't be
reported if the kernel has already paniced.  By making kasan_multishot
disable this behaviour for KASAN errors, we can still have the benefits of
panic_on_warn for non-KASAN warnings, yet be able to use kasan_multishot.

This is particularly important when running KASAN tests, which need to
trigger multiple KASAN errors: previously these would panic the system if
panic_on_warn was set, now they can run (and will panic the system should
non-KASAN warnings show up).

Signed-off-by: David Gow <davidgow@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Patricia Alfonso <trishalfonso@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/20200915035828.570483-6-davidgow@google.com
Link: https://lkml.kernel.org/r/20200910070331.3358048-6-davidgow@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:32 -07:00
Patricia Alfonso
83c4e7a036 KUnit: KASAN Integration
Integrate KASAN into KUnit testing framework.

        - Fail tests when KASAN reports an error that is not expected
        - Use KUNIT_EXPECT_KASAN_FAIL to expect a KASAN error in KASAN
	  tests
        - Expected KASAN reports pass tests and are still printed when run
          without kunit_tool (kunit_tool still bypasses the report due to the
          test passing)
	- KUnit struct in current task used to keep track of the current
	  test from KASAN code

Make use of "[PATCH v3 kunit-next 1/2] kunit: generalize kunit_resource
API beyond allocated resources" and "[PATCH v3 kunit-next 2/2] kunit: add
support for named resources" from Alan Maguire [1]

        - A named resource is added to a test when a KASAN report is
          expected
        - This resource contains a struct for kasan_data containing
          booleans representing if a KASAN report is expected and if a
          KASAN report is found

[1] (https://lore.kernel.org/linux-kselftest/1583251361-12748-1-git-send-email-alan.maguire@oracle.com/T/#t)

Signed-off-by: Patricia Alfonso <trishalfonso@google.com>
Signed-off-by: David Gow <davidgow@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Brendan Higgins <brendanhiggins@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/20200915035828.570483-3-davidgow@google.com
Link: https://lkml.kernel.org/r/20200910070331.3358048-3-davidgow@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:32 -07:00
Hui Su
74640617e1 mm/vmalloc.c: fix the comment of find_vm_area
Fix the comment of find_vm_area() and get_vm_area()

Signed-off-by: Hui Su <sh_def@163.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/20200927153034.GA199877@rlk
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:32 -07:00
Hui Su
82afbc32f2 mm/vmalloc.c: update the comment in __vmalloc_area_node()
Since c67dc62475 ("mm/vmalloc: do not call kmemleak_free() on not yet
accounted memory"), the __vunmap() have been changed to __vfree(), so
update the confusing comment().

Signed-off-by: Hui Su <sh_def@163.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Roman Penyaev <rpenyaev@suse.de>
Link: https://lkml.kernel.org/r/20200927155409.GA3315@rlk
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:32 -07:00
Alex Shi
2c3125977e mm/memory-failure.c: remove unused macro `writeback'
Unlike others we don't use the marco writeback.  so let's remove it to
tame gcc warning:

mm/memory-failure.c:827: warning: macro "writeback" is not used
[-Wunused-macros]

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Link: https://lkml.kernel.org/r/1599715096-20369-1-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:32 -07:00
Xianting Tian
c43bc03d0a mm/memory-failure: do pgoff calculation before for_each_process()
There is no need to calculate pgoff in each loop of for_each_process(), so
move it to the place before for_each_process(), which can save some CPU
cycles.

Signed-off-by: Xianting Tian <tian.xianting@h3c.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Link: http://lkml.kernel.org/r/20200818082647.34322-1-tian.xianting@h3c.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:32 -07:00
Andy Shevchenko
41a04814a7 mm/dmapool.c: replace hard coded function name with __func__
No need to hard code function name when __func__ can be used.

While here, replace specifiers for special types like dma_addr_t.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Link: http://lkml.kernel.org/r/20200814135055.24898-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:32 -07:00
Andy Shevchenko
42286f83f8 mm/dmapool.c: replace open-coded list_for_each_entry_safe()
There is a place in the code where open-coded version of
list_for_each_entry_safe() is used.  Replace that with the standard macro.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Link: http://lkml.kernel.org/r/20200814135055.24898-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:32 -07:00
Peter Xu
c78f463649 mm: remove src/dst mm parameter in copy_page_range()
Both of the mm pointers are not needed after commit 7a4830c380
("mm/fork: Pass new vma pointer into copy_page_range()").

Jason Gunthorpe also reported that the ordering of copy_page_range() is
odd.  Since working at it, reorder the parameters to be logical, by (1)
always put the dst_* fields to be before src_* fields, and (2) keep the
same type of parameters together.

[peterx@redhat.com: further reorder some parameters and line format, per Jason]
  Link: https://lkml.kernel.org/r/20201002192647.7161-1-peterx@redhat.com
[peterx@redhat.com: fix warnings]
  Link: https://lkml.kernel.org/r/20201006200138.GA6026@xz-x1

Reported-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: https://lkml.kernel.org/r/20200930204950.6668-1-peterx@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:32 -07:00
Liao Pingfang
8332326e8e mm/mmap.c: replace do_brk with do_brk_flags in comment of insert_vm_struct()
Replace do_brk with do_brk_flags in comment of insert_vm_struct(), since
do_brk was removed in following commit.

Fixes: bb177a732c ("mm: do not bug_on on incorrect length in __mm_populate()")
Signed-off-by: Liao Pingfang <liao.pingfang@zte.com.cn>
Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/1600650778-43230-1-git-send-email-wang.yi59@zte.com.cn
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:32 -07:00
Miaohe Lin
cb48841fbf mm/mmap.c: use helper function allow_write_access() in __remove_shared_vm_struct()
In commit 1da177e4c3 ("Linux-2.6.12-rc2"), the helper allow_write_access
came with the atomic_inc operation of the i_writecount field in the func
__remove_shared_vm_struct().  But it forgot to use this helper function.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/20200921115814.39680-1-linmiaohe@huawei.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:32 -07:00
Miaohe Lin
cf508b5845 mm: use helper function mapping_allow_writable()
Commit 4bb5f5d939 ("mm: allow drivers to prevent new writable mappings")
changed i_mmap_writable from unsigned int to atomic_t and add the helper
function mapping_allow_writable() to atomic_inc i_mmap_writable.  But it
forgot to use this helper function in dup_mmap() and __vma_link_file().

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Christian Kellner <christian@kellner.me>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Adrian Reber <areber@redhat.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Aleksa Sarai <cyphar@cyphar.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200917112736.7789-1-linmiaohe@huawei.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:31 -07:00
Wei Yang
0fc48a6e21 mm/mmap: check on file instead of the rb_root_cached of its address_space
In __vma_adjust(), we do the check on *root* to decide whether to adjust
the address_space.  It seems to be more meaningful to do the check on
*file* itself.  This means we are adjusting some data because it is a file
backed vma.

Since we seem to assume the address_space is valid if it is a file backed
vma, let's just replace *root* with *file* here.

Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/20200913133631.37781-2-richard.weiyang@linux.alibaba.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:31 -07:00
Wei Yang
808fbdbea0 mm/mmap: not necessary to check mapping separately
*root* with type of struct rb_root_cached is an element of *mapping*
with type of struct address_space. This implies when we have a valid
*root* it must be a part of valid *mapping*.

So we can merge these two checks together to make the code more easy to
read and to save some cpu cycles.

Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/20200913133631.37781-1-richard.weiyang@linux.alibaba.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:31 -07:00
Randy Dunlap
f1dc1685f6 mm/memory.c: fix spello of "function"
Fix typo/spello of "function".

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/e7bf180e-c558-b1d5-9a15-6d9708823c9c@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:31 -07:00
Wei Yang
f9d86a6057 mm/mmap: leave adjust_next as virtual address instead of page frame number
Instead of converting adjust_next between bytes and pages number, let's
just store the virtual address into adjust_next.

Also, this patch fixes one typo in the comment of vma_adjust_trans_huge().

[vbabka@suse.cz: changelog tweak]

Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Link: http://lkml.kernel.org/r/20200828081031.11306-1-richard.weiyang@linux.alibaba.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:31 -07:00
Wei Yang
4d1e72437b mm/mmap: leverage vma_rb_erase_ignore() to implement vma_rb_erase()
These two functions share the same logic except ignore a different vma.

Let's reuse the code.

Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/20200809232057.23477-2-richard.weiyang@linux.alibaba.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:31 -07:00
Wei Yang
7c61f917b1 mm/mmap: rename __vma_unlink_common() to __vma_unlink()
__vma_unlink_common() and __vma_unlink() are counterparts.  Since there is
no function named __vma_unlink(), let's rename __vma_unlink_common() to
__vma_unlink() to make the code more self-explanatory and easy for
audience to understand.

Otherwise we may expect there are several variants of vma_unlink() and
__vma_unlink_common() is used by them.

Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/20200809232057.23477-1-richard.weiyang@linux.alibaba.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:31 -07:00
Yanfei Xu
a7069ee3f8 mm/memory.c: replace vmf->vma with variable vma
The code has declared a vma_struct named vma which is assigned a value of
vmf->vma.  Thus, use variable vma directly here.

Signed-off-by: Yanfei Xu <yanfei.xu@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: http://lkml.kernel.org/r/20200818084607.37616-1-yanfei.xu@windriver.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:31 -07:00
Yanfei Xu
d383807aaf mm/memory.c: fix typo in __do_fault() comment
It's "pte_alloc_one", not "pte_alloc_pne". Let's fix that.

Signed-off-by: Yanfei Xu <yanfei.xu@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Link: http://lkml.kernel.org/r/20200818104339.5310-1-yanfei.xu@windriver.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:31 -07:00
Ralph Campbell
9a137153fc mm/memcg: fix device private memcg accounting
The code in mc_handle_swap_pte() checks for non_swap_entry() and returns
NULL before checking is_device_private_entry() so device private pages are
never handled.  Fix this by checking for non_swap_entry() after handling
device private swap PTEs.

I assume the memory cgroup accounting would be off somehow when moving
a process to another memory cgroup.  Currently, the device private page
is charged like a normal anonymous page when allocated and is uncharged
when the page is freed so I think that path is OK.

Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Link: https://lkml.kernel.org/r/20201009215952.2726-1-rcampbell@nvidia.com
xFixes: c733a82874 ("mm/memcontrol: support MEMORY_DEVICE_PRIVATE")
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:31 -07:00
Bharata B Rao
d1b2cf6cb8 mm: memcg/slab: uncharge during kmem_cache_free_bulk()
Object cgroup charging is done for all the objects during allocation, but
during freeing, uncharging ends up happening for only one object in the
case of bulk allocation/freeing.

Fix this by having a separate call to uncharge all the objects from
kmem_cache_free_bulk() and by modifying memcg_slab_free_hook() to take
care of bulk uncharging.

Fixes: 964d4bd370 ("mm: memcg/slab: save obj_cgroup for non-root slab objects"
Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20201009060423.390479-1-bharata@linux.ibm.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:31 -07:00
Miaohe Lin
7a52d4d88a mm: memcontrol: reword obsolete comment of mem_cgroup_unmark_under_oom()
Since commit 79dfdaccd1 ("memcg: make oom_lock 0 and 1 based rather than
counter"), the mem_cgroup_unmark_under_oom() is added and the comment of
the mem_cgroup_oom_unlock() is moved here.  But this comment make no sense
here because mem_cgroup_oom_lock() does not operate on under_oom field.
So we reword the comment as this would be helpful.  [Thanks Michal Hocko
for rewording this comment.]

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Link: https://lkml.kernel.org/r/20200930095336.21323-1-linmiaohe@huawei.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:30 -07:00
Miaohe Lin
d437024e69 mm/page_counter: correct the obsolete func name in the comment of page_counter_try_charge()
Since commit bbec2e1517 ("mm: rename page_counter's count/limit into
usage/max"), page_counter_limit() is renamed to page_counter_set_max().
So replace page_counter_limit with page_counter_set_max in comment.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Link: https://lkml.kernel.org/r/20200917113629.14382-1-linmiaohe@huawei.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:30 -07:00
Muchun Song
5f9a4f4a70 mm: memcontrol: add the missing numa_stat interface for cgroup v2
In the cgroup v1, we have a numa_stat interface.  This is useful for
providing visibility into the numa locality information within an memcg
since the pages are allowed to be allocated from any physical node.  One
of the use cases is evaluating application performance by combining this
information with the application's CPU allocation.  But the cgroup v2 does
not.  So this patch adds the missing information.

Suggested-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Zefan Li <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Link: https://lkml.kernel.org/r/20200916100030.71698-2-songmuchun@bytedance.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:30 -07:00
Waiman Long
bd0b230fe1 mm/memcg: unify swap and memsw page counters
The swap page counter is v2 only while memsw is v1 only.  As v1 and v2
controllers cannot be active at the same time, there is no point to keep
both swap and memsw page counters in mem_cgroup.  The previous patch has
made sure that memsw page counter is updated and accessed only when in v1
code paths.  So it is now safe to alias the v1 memsw page counter to v2
swap page counter.  This saves 14 long's in the size of mem_cgroup.  This
is a saving of 112 bytes for 64-bit archs.

While at it, also document which page counters are used in v1 and/or v2.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Chris Down <chris@chrisdown.name>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Yafang Shao <laoar.shao@gmail.com>
Link: https://lkml.kernel.org/r/20200914024452.19167-4-longman@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:30 -07:00
Waiman Long
8d387a5f17 mm/memcg: simplify mem_cgroup_get_max()
mem_cgroup_get_max() used to get memory+swap max from both the v1 memsw
and v2 memory+swap page counters & return the maximum of these 2 values.
This is redundant and it is more efficient to just get either the v1 or
the v2 values depending on which one is currently in use.

[longman@redhat.com: v4]
  Link: https://lkml.kernel.org/r/20200914150928.7841-1-longman@redhat.com

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Chris Down <chris@chrisdown.name>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Yafang Shao <laoar.shao@gmail.com>
Link: https://lkml.kernel.org/r/20200914024452.19167-3-longman@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:30 -07:00
Waiman Long
f9f84ec56f mm/memcg: clean up obsolete enum charge_type
Patch series "mm/memcg: Miscellaneous cleanups and streamlining", v2.

This patch (of 3):

Since commit 0a31bc97c8 ("mm: memcontrol: rewrite uncharge API") and
commit 00501b531c ("mm: memcontrol: rewrite charge API") in v3.17, the
enum charge_type was no longer used anywhere.  However, the enum itself
was not removed at that time.  Remove the obsolete enum charge_type now.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Chris Down <chris@chrisdown.name>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Yafang Shao <laoar.shao@gmail.com>
Link: https://lkml.kernel.org/r/20200914024452.19167-1-longman@redhat.com
Link: https://lkml.kernel.org/r/20200914024452.19167-2-longman@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:30 -07:00
Miaohe Lin
05bdc520b3 mm: memcontrol: correct the comment of mem_cgroup_iter()
Since commit bbec2e1517 ("mm: rename page_counter's count/limit into
usage/max"), the arg @reclaim has no priority field anymore.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Link: https://lkml.kernel.org/r/20200913094129.44558-1-linmiaohe@huawei.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:30 -07:00
Roman Gushchin
19b629c979 mm: memcg/slab: fix racy access to page->mem_cgroup in mem_cgroup_from_obj()
mem_cgroup_from_obj() checks the lowest bit of the page->mem_cgroup
pointer to determine if the page has an attached obj_cgroup vector instead
of a regular memcg pointer.  If it's not set, it simple returns the
page->mem_cgroup value as a struct mem_cgroup pointer.

The commit 10befea91b ("mm: memcg/slab: use a single set of kmem_caches
for all allocations") changed the moment when this bit is set: if
previously it was set on the allocation of the slab page, now it can be
set well after, when the first accounted object is allocated on this page.

It opened a race: if page->mem_cgroup is set concurrently after the first
page_has_obj_cgroups(page) check, a pointer to the obj_cgroups array can
be returned as a memory cgroup pointer.

A simple check for page->mem_cgroup pointer for NULL before the
page_has_obj_cgroups() check fixes the race.  Indeed, if the pointer is
not NULL, it's either a simple mem_cgroup pointer or a pointer to
obj_cgroup vector.  The pointer can be asynchronously changed from NULL to
(obj_cgroup_vec | 0x1UL), but can't be changed from a valid memcg pointer
to objcg vector or back.

If the object passed to mem_cgroup_from_obj() is a slab object and
page->mem_cgroup is NULL, it means that the object is not accounted, so
the function must return NULL.

I've discovered the race looking at the code, so far I haven't seen it in
the wild.

Fixes: 10befea91b ("mm: memcg/slab: use a single set of kmem_caches for all allocations")
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Link: https://lkml.kernel.org/r/20200910022435.2773735-1-guro@fb.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:30 -07:00
Gustavo A. R. Silva
61e604e636 mm: memcontrol: use the preferred form for passing the size of a structure type
Use the preferred form for passing the size of a structure type.  The
alternative form where the structure type is spelled out hurts readability
and introduces an opportunity for a bug when the object type is changed
but the corresponding object identifier to which the sizeof operator is
applied is not.

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Link: https://lkml.kernel.org/r/773e013ff2f07fe2a0b47153f14dea054c0c04f1.1596214831.git.gustavoars@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:30 -07:00
Gustavo A. R. Silva
e90342e6d2 mm: memcontrol: use flex_array_size() helper in memcpy()
Make use of the flex_array_size() helper to calculate the size of a
flexible array member within an enclosing structure.

This helper offers defense-in-depth against potential integer overflows,
while at the same time makes it explicitly clear that we are dealing with
a flexible array member.

Also, remove unnecessary braces.

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Link: https://lkml.kernel.org/r/ddd60dae2d9aea1ccdd2be66634815c93696125e.1596214831.git.gustavoars@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:30 -07:00
Ira Weiny
433e7d3177 mm/memremap.c: convert devmap static branch to {inc,dec}
While reviewing Protection Key Supervisor support it was pointed out that
using a counter to track static branch enable was an anti-pattern which
was better solved using the provided static_branch_{inc,dec} functions.[1]

Fix up devmap_managed_key to work the same way.  Also this should be safer
because there is a very small (very unlikely) race when multiple callers
try to enable at the same time.

[1] https://lore.kernel.org/lkml/20200714194031.GI5523@worktop.programming.kicks-ass.net/

Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Link: https://lkml.kernel.org/r/20200810235319.2796597-1-ira.weiny@intel.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13 18:38:30 -07:00