<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/include/linux, branch v5.12-rc5</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>Merge tag 'locking-urgent-2021-03-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2021-03-28T19:12:22+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-03-28T19:12:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=47fbbc94dab61a1385f21a0a209c61b5d6b0a215'/>
<id>47fbbc94dab61a1385f21a0a209c61b5d6b0a215</id>
<content type='text'>
Pull locking fix from Ingo Molnar:
 "Fix the non-debug mutex_lock_io_nested() method to map to
  mutex_lock_io() instead of mutex_lock().

  Right now nothing uses this API explicitly, but this is an
  accident waiting to happen"

* tag 'locking-urgent-2021-03-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/mutex: Fix non debug version of mutex_lock_io_nested()
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull locking fix from Ingo Molnar:
 "Fix the non-debug mutex_lock_io_nested() method to map to
  mutex_lock_io() instead of mutex_lock().

  Right now nothing uses this API explicitly, but this is an
  accident waiting to happen"

* tag 'locking-urgent-2021-03-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/mutex: Fix non debug version of mutex_lock_io_nested()
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'for-5.12/dm-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm</title>
<updated>2021-03-26T19:21:05+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-03-26T19:21:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0f4498cef9f5cd18d7c6639a2a902ec1edc5be4e'/>
<id>0f4498cef9f5cd18d7c6639a2a902ec1edc5be4e</id>
<content type='text'>
Pull device mapper fixes from Mike Snitzer:

 - Fix DM verity target's optional argument processing.

 - Fix DM core's zoned model and zone sectors checks.

 - Fix spurious "detected capacity change" pr_info() when creating new
   DM device.

 - Fix DM ioctl out of bounds array access in handling of
   DM_LIST_DEVICES_CMD when no devices exist.

* tag 'for-5.12/dm-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm ioctl: fix out of bounds array access when no devices
  dm: don't report "detected capacity change" on device creation
  dm table: Fix zoned model check and zone sectors check
  dm verity: fix DM_VERITY_OPTS_MAX value
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull device mapper fixes from Mike Snitzer:

 - Fix DM verity target's optional argument processing.

 - Fix DM core's zoned model and zone sectors checks.

 - Fix spurious "detected capacity change" pr_info() when creating new
   DM device.

 - Fix DM ioctl out of bounds array access in handling of
   DM_LIST_DEVICES_CMD when no devices exist.

* tag 'for-5.12/dm-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm ioctl: fix out of bounds array access when no devices
  dm: don't report "detected capacity change" on device creation
  dm table: Fix zoned model check and zone sectors check
  dm verity: fix DM_VERITY_OPTS_MAX value
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'akpm' (patches from Andrew)</title>
<updated>2021-03-25T18:43:43+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-03-25T18:43:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=002322402dafd846c424ffa9240a937f49b48c42'/>
<id>002322402dafd846c424ffa9240a937f49b48c42</id>
<content type='text'>
Merge misc fixes from Andrew Morton:
 "14 patches.

  Subsystems affected by this patch series: mm (hugetlb, kasan, gup,
  selftests, z3fold, kfence, memblock, and highmem), squashfs, ia64,
  gcov, and mailmap"

* emailed patches from Andrew Morton &lt;akpm@linux-foundation.org&gt;:
  mailmap: update Andrey Konovalov's email address
  mm/highmem: fix CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP
  mm: memblock: fix section mismatch warning again
  kfence: make compatible with kmemleak
  gcov: fix clang-11+ support
  ia64: fix format strings for err_inject
  ia64: mca: allocate early mca with GFP_ATOMIC
  squashfs: fix xattr id and id lookup sanity checks
  squashfs: fix inode lookup sanity checks
  z3fold: prevent reclaim/free race for headless pages
  selftests/vm: fix out-of-tree build
  mm/mmu_notifiers: ensure range_end() is paired with range_start()
  kasan: fix per-page tags for non-page_alloc pages
  hugetlb_cgroup: fix imbalanced css_get and css_put pair for shared mappings
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Merge misc fixes from Andrew Morton:
 "14 patches.

  Subsystems affected by this patch series: mm (hugetlb, kasan, gup,
  selftests, z3fold, kfence, memblock, and highmem), squashfs, ia64,
  gcov, and mailmap"

* emailed patches from Andrew Morton &lt;akpm@linux-foundation.org&gt;:
  mailmap: update Andrey Konovalov's email address
  mm/highmem: fix CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP
  mm: memblock: fix section mismatch warning again
  kfence: make compatible with kmemleak
  gcov: fix clang-11+ support
  ia64: fix format strings for err_inject
  ia64: mca: allocate early mca with GFP_ATOMIC
  squashfs: fix xattr id and id lookup sanity checks
  squashfs: fix inode lookup sanity checks
  z3fold: prevent reclaim/free race for headless pages
  selftests/vm: fix out-of-tree build
  mm/mmu_notifiers: ensure range_end() is paired with range_start()
  kasan: fix per-page tags for non-page_alloc pages
  hugetlb_cgroup: fix imbalanced css_get and css_put pair for shared mappings
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: memblock: fix section mismatch warning again</title>
<updated>2021-03-25T16:22:55+00:00</updated>
<author>
<name>Mike Rapoport</name>
<email>rppt@linux.ibm.com</email>
</author>
<published>2021-03-25T04:37:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a024b7c2850dddd01e65b8270f0971deaf272f27'/>
<id>a024b7c2850dddd01e65b8270f0971deaf272f27</id>
<content type='text'>
Commit 34dc2efb39a2 ("memblock: fix section mismatch warning") marked
memblock_bottom_up() and memblock_set_bottom_up() as __init, but they
could be referenced from non-init functions like
memblock_find_in_range_node() on architectures that enable
CONFIG_ARCH_KEEP_MEMBLOCK.

For such builds kernel test robot reports:

   WARNING: modpost: vmlinux.o(.text+0x74fea4): Section mismatch in reference from the function memblock_find_in_range_node() to the function .init.text:memblock_bottom_up()
   The function memblock_find_in_range_node() references the function __init memblock_bottom_up().
   This is often because memblock_find_in_range_node lacks a __init  annotation or the annotation of memblock_bottom_up is wrong.

Replace __init annotations with __init_memblock annotations so that the
appropriate section will be selected depending on
CONFIG_ARCH_KEEP_MEMBLOCK.

Link: https://lore.kernel.org/lkml/202103160133.UzhgY0wt-lkp@intel.com
Link: https://lkml.kernel.org/r/20210316171347.14084-1-rppt@kernel.org
Fixes: 34dc2efb39a2 ("memblock: fix section mismatch warning")
Signed-off-by: Mike Rapoport &lt;rppt@linux.ibm.com&gt;
Reviewed-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Reviewed-by: David Hildenbrand &lt;david@redhat.com&gt;
Acked-by: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit 34dc2efb39a2 ("memblock: fix section mismatch warning") marked
memblock_bottom_up() and memblock_set_bottom_up() as __init, but they
could be referenced from non-init functions like
memblock_find_in_range_node() on architectures that enable
CONFIG_ARCH_KEEP_MEMBLOCK.

For such builds kernel test robot reports:

   WARNING: modpost: vmlinux.o(.text+0x74fea4): Section mismatch in reference from the function memblock_find_in_range_node() to the function .init.text:memblock_bottom_up()
   The function memblock_find_in_range_node() references the function __init memblock_bottom_up().
   This is often because memblock_find_in_range_node lacks a __init  annotation or the annotation of memblock_bottom_up is wrong.

Replace __init annotations with __init_memblock annotations so that the
appropriate section will be selected depending on
CONFIG_ARCH_KEEP_MEMBLOCK.

Link: https://lore.kernel.org/lkml/202103160133.UzhgY0wt-lkp@intel.com
Link: https://lkml.kernel.org/r/20210316171347.14084-1-rppt@kernel.org
Fixes: 34dc2efb39a2 ("memblock: fix section mismatch warning")
Signed-off-by: Mike Rapoport &lt;rppt@linux.ibm.com&gt;
Reviewed-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Reviewed-by: David Hildenbrand &lt;david@redhat.com&gt;
Acked-by: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm/mmu_notifiers: ensure range_end() is paired with range_start()</title>
<updated>2021-03-25T16:22:55+00:00</updated>
<author>
<name>Sean Christopherson</name>
<email>seanjc@google.com</email>
</author>
<published>2021-03-25T04:37:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c2655835fd8cabdfe7dab737253de3ffb88da126'/>
<id>c2655835fd8cabdfe7dab737253de3ffb88da126</id>
<content type='text'>
If one or more notifiers fails .invalidate_range_start(), invoke
.invalidate_range_end() for "all" notifiers.  If there are multiple
notifiers, those that did not fail are expecting _start() and _end() to
be paired, e.g.  KVM's mmu_notifier_count would become imbalanced.
Disallow notifiers that can fail _start() from implementing _end() so
that it's unnecessary to either track which notifiers rejected _start(),
or had already succeeded prior to a failed _start().

Note, the existing behavior of calling _start() on all notifiers even
after a previous notifier failed _start() was an unintented "feature".
Make it canon now that the behavior is depended on for correctness.

As of today, the bug is likely benign:

  1. The only caller of the non-blocking notifier is OOM kill.
  2. The only notifiers that can fail _start() are the i915 and Nouveau
     drivers.
  3. The only notifiers that utilize _end() are the SGI UV GRU driver
     and KVM.
  4. The GRU driver will never coincide with the i195/Nouveau drivers.
  5. An imbalanced kvm-&gt;mmu_notifier_count only causes soft lockup in the
     _guest_, and the guest is already doomed due to being an OOM victim.

Fix the bug now to play nice with future usage, e.g.  KVM has a
potential use case for blocking memslot updates in KVM while an
invalidation is in-progress, and failure to unblock would result in said
updates being blocked indefinitely and hanging.

Found by inspection.  Verified by adding a second notifier in KVM that
periodically returns -EAGAIN on non-blockable ranges, triggering OOM,
and observing that KVM exits with an elevated notifier count.

Link: https://lkml.kernel.org/r/20210311180057.1582638-1-seanjc@google.com
Fixes: 93065ac753e4 ("mm, oom: distinguish blockable mode for mmu notifiers")
Signed-off-by: Sean Christopherson &lt;seanjc@google.com&gt;
Suggested-by: Jason Gunthorpe &lt;jgg@ziepe.ca&gt;
Reviewed-by: Jason Gunthorpe &lt;jgg@nvidia.com&gt;
Cc: David Rientjes &lt;rientjes@google.com&gt;
Cc: Ben Gardon &lt;bgardon@google.com&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: "Jérôme Glisse" &lt;jglisse@redhat.com&gt;
Cc: Andrea Arcangeli &lt;aarcange@redhat.com&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Dimitri Sivanich &lt;dimitri.sivanich@hpe.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If one or more notifiers fails .invalidate_range_start(), invoke
.invalidate_range_end() for "all" notifiers.  If there are multiple
notifiers, those that did not fail are expecting _start() and _end() to
be paired, e.g.  KVM's mmu_notifier_count would become imbalanced.
Disallow notifiers that can fail _start() from implementing _end() so
that it's unnecessary to either track which notifiers rejected _start(),
or had already succeeded prior to a failed _start().

Note, the existing behavior of calling _start() on all notifiers even
after a previous notifier failed _start() was an unintented "feature".
Make it canon now that the behavior is depended on for correctness.

As of today, the bug is likely benign:

  1. The only caller of the non-blocking notifier is OOM kill.
  2. The only notifiers that can fail _start() are the i915 and Nouveau
     drivers.
  3. The only notifiers that utilize _end() are the SGI UV GRU driver
     and KVM.
  4. The GRU driver will never coincide with the i195/Nouveau drivers.
  5. An imbalanced kvm-&gt;mmu_notifier_count only causes soft lockup in the
     _guest_, and the guest is already doomed due to being an OOM victim.

Fix the bug now to play nice with future usage, e.g.  KVM has a
potential use case for blocking memslot updates in KVM while an
invalidation is in-progress, and failure to unblock would result in said
updates being blocked indefinitely and hanging.

Found by inspection.  Verified by adding a second notifier in KVM that
periodically returns -EAGAIN on non-blockable ranges, triggering OOM,
and observing that KVM exits with an elevated notifier count.

Link: https://lkml.kernel.org/r/20210311180057.1582638-1-seanjc@google.com
Fixes: 93065ac753e4 ("mm, oom: distinguish blockable mode for mmu notifiers")
Signed-off-by: Sean Christopherson &lt;seanjc@google.com&gt;
Suggested-by: Jason Gunthorpe &lt;jgg@ziepe.ca&gt;
Reviewed-by: Jason Gunthorpe &lt;jgg@nvidia.com&gt;
Cc: David Rientjes &lt;rientjes@google.com&gt;
Cc: Ben Gardon &lt;bgardon@google.com&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: "Jérôme Glisse" &lt;jglisse@redhat.com&gt;
Cc: Andrea Arcangeli &lt;aarcange@redhat.com&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Dimitri Sivanich &lt;dimitri.sivanich@hpe.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>kasan: fix per-page tags for non-page_alloc pages</title>
<updated>2021-03-25T16:22:55+00:00</updated>
<author>
<name>Andrey Konovalov</name>
<email>andreyknvl@google.com</email>
</author>
<published>2021-03-25T04:37:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=cf10bd4c4aff8dd64d1aa7f2a529d0c672bc16af'/>
<id>cf10bd4c4aff8dd64d1aa7f2a529d0c672bc16af</id>
<content type='text'>
To allow performing tag checks on page_alloc addresses obtained via
page_address(), tag-based KASAN modes store tags for page_alloc
allocations in page-&gt;flags.

Currently, the default tag value stored in page-&gt;flags is 0x00.
Therefore, page_address() returns a 0x00ffff...  address for pages that
were not allocated via page_alloc.

This might cause problems.  A particular case we encountered is a
conflict with KFENCE.  If a KFENCE-allocated slab object is being freed
via kfree(page_address(page) + offset), the address passed to kfree()
will get tagged with 0x00 (as slab pages keep the default per-page
tags).  This leads to is_kfence_address() check failing, and a KFENCE
object ending up in normal slab freelist, which causes memory
corruptions.

This patch changes the way KASAN stores tag in page-flags: they are now
stored xor'ed with 0xff.  This way, KASAN doesn't need to initialize
per-page flags for every created page, which might be slow.

With this change, page_address() returns natively-tagged (with 0xff)
pointers for pages that didn't have tags set explicitly.

This patch fixes the encountered conflict with KFENCE and prevents more
similar issues that can occur in the future.

Link: https://lkml.kernel.org/r/1a41abb11c51b264511d9e71c303bb16d5cb367b.1615475452.git.andreyknvl@google.com
Fixes: 2813b9c02962 ("kasan, mm, arm64: tag non slab memory allocated via pagealloc")
Signed-off-by: Andrey Konovalov &lt;andreyknvl@google.com&gt;
Reviewed-by: Marco Elver &lt;elver@google.com&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: Vincenzo Frascino &lt;vincenzo.frascino@arm.com&gt;
Cc: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Cc: Andrey Ryabinin &lt;aryabinin@virtuozzo.com&gt;
Cc: Alexander Potapenko &lt;glider@google.com&gt;
Cc: Peter Collingbourne &lt;pcc@google.com&gt;
Cc: Evgenii Stepanov &lt;eugenis@google.com&gt;
Cc: Branislav Rankov &lt;Branislav.Rankov@arm.com&gt;
Cc: Kevin Brodsky &lt;kevin.brodsky@arm.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
To allow performing tag checks on page_alloc addresses obtained via
page_address(), tag-based KASAN modes store tags for page_alloc
allocations in page-&gt;flags.

Currently, the default tag value stored in page-&gt;flags is 0x00.
Therefore, page_address() returns a 0x00ffff...  address for pages that
were not allocated via page_alloc.

This might cause problems.  A particular case we encountered is a
conflict with KFENCE.  If a KFENCE-allocated slab object is being freed
via kfree(page_address(page) + offset), the address passed to kfree()
will get tagged with 0x00 (as slab pages keep the default per-page
tags).  This leads to is_kfence_address() check failing, and a KFENCE
object ending up in normal slab freelist, which causes memory
corruptions.

This patch changes the way KASAN stores tag in page-flags: they are now
stored xor'ed with 0xff.  This way, KASAN doesn't need to initialize
per-page flags for every created page, which might be slow.

With this change, page_address() returns natively-tagged (with 0xff)
pointers for pages that didn't have tags set explicitly.

This patch fixes the encountered conflict with KFENCE and prevents more
similar issues that can occur in the future.

Link: https://lkml.kernel.org/r/1a41abb11c51b264511d9e71c303bb16d5cb367b.1615475452.git.andreyknvl@google.com
Fixes: 2813b9c02962 ("kasan, mm, arm64: tag non slab memory allocated via pagealloc")
Signed-off-by: Andrey Konovalov &lt;andreyknvl@google.com&gt;
Reviewed-by: Marco Elver &lt;elver@google.com&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: Vincenzo Frascino &lt;vincenzo.frascino@arm.com&gt;
Cc: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Cc: Andrey Ryabinin &lt;aryabinin@virtuozzo.com&gt;
Cc: Alexander Potapenko &lt;glider@google.com&gt;
Cc: Peter Collingbourne &lt;pcc@google.com&gt;
Cc: Evgenii Stepanov &lt;eugenis@google.com&gt;
Cc: Branislav Rankov &lt;Branislav.Rankov@arm.com&gt;
Cc: Kevin Brodsky &lt;kevin.brodsky@arm.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>hugetlb_cgroup: fix imbalanced css_get and css_put pair for shared mappings</title>
<updated>2021-03-25T16:22:55+00:00</updated>
<author>
<name>Miaohe Lin</name>
<email>linmiaohe@huawei.com</email>
</author>
<published>2021-03-25T04:37:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=d85aecf2844ff02a0e5f077252b2461d4f10c9f0'/>
<id>d85aecf2844ff02a0e5f077252b2461d4f10c9f0</id>
<content type='text'>
The current implementation of hugetlb_cgroup for shared mappings could
have different behavior.  Consider the following two scenarios:

 1.Assume initial css reference count of hugetlb_cgroup is 1:
  1.1 Call hugetlb_reserve_pages with from = 1, to = 2. So css reference
      count is 2 associated with 1 file_region.
  1.2 Call hugetlb_reserve_pages with from = 2, to = 3. So css reference
      count is 3 associated with 2 file_region.
  1.3 coalesce_file_region will coalesce these two file_regions into
      one. So css reference count is 3 associated with 1 file_region
      now.

 2.Assume initial css reference count of hugetlb_cgroup is 1 again:
  2.1 Call hugetlb_reserve_pages with from = 1, to = 3. So css reference
      count is 2 associated with 1 file_region.

Therefore, we might have one file_region while holding one or more css
reference counts. This inconsistency could lead to imbalanced css_get()
and css_put() pair. If we do css_put one by one (i.g. hole punch case),
scenario 2 would put one more css reference. If we do css_put all
together (i.g. truncate case), scenario 1 will leak one css reference.

The imbalanced css_get() and css_put() pair would result in a non-zero
reference when we try to destroy the hugetlb cgroup. The hugetlb cgroup
directory is removed __but__ associated resource is not freed. This
might result in OOM or can not create a new hugetlb cgroup in a busy
workload ultimately.

In order to fix this, we have to make sure that one file_region must
hold exactly one css reference. So in coalesce_file_region case, we
should release one css reference before coalescence. Also only put css
reference when the entire file_region is removed.

The last thing to note is that the caller of region_add() will only hold
one reference to h_cg-&gt;css for the whole contiguous reservation region.
But this area might be scattered when there are already some
file_regions reside in it. As a result, many file_regions may share only
one h_cg-&gt;css reference. In order to ensure that one file_region must
hold exactly one css reference, we should do css_get() for each
file_region and release the reference held by caller when they are done.

[linmiaohe@huawei.com: fix imbalanced css_get and css_put pair for shared mappings]
  Link: https://lkml.kernel.org/r/20210316023002.53921-1-linmiaohe@huawei.com

Link: https://lkml.kernel.org/r/20210301120540.37076-1-linmiaohe@huawei.com
Fixes: 075a61d07a8e ("hugetlb_cgroup: add accounting for shared mappings")
Reported-by: kernel test robot &lt;lkp@intel.com&gt; (auto build test ERROR)
Signed-off-by: Miaohe Lin &lt;linmiaohe@huawei.com&gt;
Reviewed-by: Mike Kravetz &lt;mike.kravetz@oracle.com&gt;
Cc: Aneesh Kumar K.V &lt;aneesh.kumar@linux.vnet.ibm.com&gt;
Cc: Wanpeng Li &lt;liwp.linux@gmail.com&gt;
Cc: Mina Almasry &lt;almasrymina@google.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The current implementation of hugetlb_cgroup for shared mappings could
have different behavior.  Consider the following two scenarios:

 1.Assume initial css reference count of hugetlb_cgroup is 1:
  1.1 Call hugetlb_reserve_pages with from = 1, to = 2. So css reference
      count is 2 associated with 1 file_region.
  1.2 Call hugetlb_reserve_pages with from = 2, to = 3. So css reference
      count is 3 associated with 2 file_region.
  1.3 coalesce_file_region will coalesce these two file_regions into
      one. So css reference count is 3 associated with 1 file_region
      now.

 2.Assume initial css reference count of hugetlb_cgroup is 1 again:
  2.1 Call hugetlb_reserve_pages with from = 1, to = 3. So css reference
      count is 2 associated with 1 file_region.

Therefore, we might have one file_region while holding one or more css
reference counts. This inconsistency could lead to imbalanced css_get()
and css_put() pair. If we do css_put one by one (i.g. hole punch case),
scenario 2 would put one more css reference. If we do css_put all
together (i.g. truncate case), scenario 1 will leak one css reference.

The imbalanced css_get() and css_put() pair would result in a non-zero
reference when we try to destroy the hugetlb cgroup. The hugetlb cgroup
directory is removed __but__ associated resource is not freed. This
might result in OOM or can not create a new hugetlb cgroup in a busy
workload ultimately.

In order to fix this, we have to make sure that one file_region must
hold exactly one css reference. So in coalesce_file_region case, we
should release one css reference before coalescence. Also only put css
reference when the entire file_region is removed.

The last thing to note is that the caller of region_add() will only hold
one reference to h_cg-&gt;css for the whole contiguous reservation region.
But this area might be scattered when there are already some
file_regions reside in it. As a result, many file_regions may share only
one h_cg-&gt;css reference. In order to ensure that one file_region must
hold exactly one css reference, we should do css_get() for each
file_region and release the reference held by caller when they are done.

[linmiaohe@huawei.com: fix imbalanced css_get and css_put pair for shared mappings]
  Link: https://lkml.kernel.org/r/20210316023002.53921-1-linmiaohe@huawei.com

Link: https://lkml.kernel.org/r/20210301120540.37076-1-linmiaohe@huawei.com
Fixes: 075a61d07a8e ("hugetlb_cgroup: add accounting for shared mappings")
Reported-by: kernel test robot &lt;lkp@intel.com&gt; (auto build test ERROR)
Signed-off-by: Miaohe Lin &lt;linmiaohe@huawei.com&gt;
Reviewed-by: Mike Kravetz &lt;mike.kravetz@oracle.com&gt;
Cc: Aneesh Kumar K.V &lt;aneesh.kumar@linux.vnet.ibm.com&gt;
Cc: Wanpeng Li &lt;liwp.linux@gmail.com&gt;
Cc: Mina Almasry &lt;almasrymina@google.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net</title>
<updated>2021-03-25T01:16:04+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-03-25T01:16:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e138138003eb3b3d06cc91cf2e8c5dec77e2a31e'/>
<id>e138138003eb3b3d06cc91cf2e8c5dec77e2a31e</id>
<content type='text'>
Pull networking fixes from David Miller:
 "Various fixes, all over:

   1) Fix overflow in ptp_qoriq_adjfine(), from Yangbo Lu.

   2) Always store the rx queue mapping in veth, from Maciej
      Fijalkowski.

   3) Don't allow vmlinux btf in map_create, from Alexei Starovoitov.

   4) Fix memory leak in octeontx2-af from Colin Ian King.

   5) Use kvalloc in bpf x86 JIT for storing jit'd addresses, from
      Yonghong Song.

   6) Fix tx ptp stats in mlx5, from Aya Levin.

   7) Check correct ip version in tun decap, fropm Roi Dayan.

   8) Fix rate calculation in mlx5 E-Switch code, from arav Pandit.

   9) Work item memork leak in mlx5, from Shay Drory.

  10) Fix ip6ip6 tunnel crash with bpf, from Daniel Borkmann.

  11) Lack of preemptrion awareness in macvlan, from Eric Dumazet.

  12) Fix data race in pxa168_eth, from Pavel Andrianov.

  13) Range validate stab in red_check_params(), from Eric Dumazet.

  14) Inherit vlan filtering setting properly in b53 driver, from
      Florian Fainelli.

  15) Fix rtnl locking in igc driver, from Sasha Neftin.

  16) Pause handling fixes in igc driver, from Muhammad Husaini
      Zulkifli.

  17) Missing rtnl locking in e1000_reset_task, from Vitaly Lifshits.

  18) Use after free in qlcnic, from Lv Yunlong.

  19) fix crash in fritzpci mISDN, from Tong Zhang.

  20) Premature rx buffer reuse in igb, from Li RongQing.

  21) Missing termination of ip[a driver message handler arrays, from
      Alex Elder.

  22) Fix race between "x25_close" and "x25_xmit"/"x25_rx" in hdlc_x25
      driver, from Xie He.

  23) Use after free in c_can_pci_remove(), from Tong Zhang.

  24) Uninitialized variable use in nl80211, from Jarod Wilson.

  25) Off by one size calc in bpf verifier, from Piotr Krysiuk.

  26) Use delayed work instead of deferrable for flowtable GC, from
      Yinjun Zhang.

  27) Fix infinite loop in NPC unmap of octeontx2 driver, from
      Hariprasad Kelam.

  28) Fix being unable to change MTU of dwmac-sun8i devices due to lack
      of fifo sizes, from Corentin Labbe.

  29) DMA use after free in r8169 with WoL, fom Heiner Kallweit.

  30) Mismatched prototypes in isdn-capi, from Arnd Bergmann.

  31) Fix psample UAPI breakage, from Ido Schimmel"

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (171 commits)
  psample: Fix user API breakage
  math: Export mul_u64_u64_div_u64
  ch_ktls: fix enum-conversion warning
  octeontx2-af: Fix memory leak of object buf
  ptp_qoriq: fix overflow in ptp_qoriq_adjfine() u64 calcalation
  net: bridge: don't notify switchdev for local FDB addresses
  net/sched: act_ct: clear post_ct if doing ct_clear
  net: dsa: don't assign an error value to tag_ops
  isdn: capi: fix mismatched prototypes
  net/mlx5: SF, do not use ecpu bit for vhca state processing
  net/mlx5e: Fix division by 0 in mlx5e_select_queue
  net/mlx5e: Fix error path for ethtool set-priv-flag
  net/mlx5e: Offload tuple rewrite for non-CT flows
  net/mlx5e: Allow to match on MPLS parameters only for MPLS over UDP
  net/mlx5: Add back multicast stats for uplink representor
  net: ipconfig: ic_dev can be NULL in ic_close_devs
  MAINTAINERS: Combine "QLOGIC QLGE 10Gb ETHERNET DRIVER" sections into one
  docs: networking: Fix a typo
  r8169: fix DMA being used after buffer free if WoL is enabled
  net: ipa: fix init header command validation
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull networking fixes from David Miller:
 "Various fixes, all over:

   1) Fix overflow in ptp_qoriq_adjfine(), from Yangbo Lu.

   2) Always store the rx queue mapping in veth, from Maciej
      Fijalkowski.

   3) Don't allow vmlinux btf in map_create, from Alexei Starovoitov.

   4) Fix memory leak in octeontx2-af from Colin Ian King.

   5) Use kvalloc in bpf x86 JIT for storing jit'd addresses, from
      Yonghong Song.

   6) Fix tx ptp stats in mlx5, from Aya Levin.

   7) Check correct ip version in tun decap, fropm Roi Dayan.

   8) Fix rate calculation in mlx5 E-Switch code, from arav Pandit.

   9) Work item memork leak in mlx5, from Shay Drory.

  10) Fix ip6ip6 tunnel crash with bpf, from Daniel Borkmann.

  11) Lack of preemptrion awareness in macvlan, from Eric Dumazet.

  12) Fix data race in pxa168_eth, from Pavel Andrianov.

  13) Range validate stab in red_check_params(), from Eric Dumazet.

  14) Inherit vlan filtering setting properly in b53 driver, from
      Florian Fainelli.

  15) Fix rtnl locking in igc driver, from Sasha Neftin.

  16) Pause handling fixes in igc driver, from Muhammad Husaini
      Zulkifli.

  17) Missing rtnl locking in e1000_reset_task, from Vitaly Lifshits.

  18) Use after free in qlcnic, from Lv Yunlong.

  19) fix crash in fritzpci mISDN, from Tong Zhang.

  20) Premature rx buffer reuse in igb, from Li RongQing.

  21) Missing termination of ip[a driver message handler arrays, from
      Alex Elder.

  22) Fix race between "x25_close" and "x25_xmit"/"x25_rx" in hdlc_x25
      driver, from Xie He.

  23) Use after free in c_can_pci_remove(), from Tong Zhang.

  24) Uninitialized variable use in nl80211, from Jarod Wilson.

  25) Off by one size calc in bpf verifier, from Piotr Krysiuk.

  26) Use delayed work instead of deferrable for flowtable GC, from
      Yinjun Zhang.

  27) Fix infinite loop in NPC unmap of octeontx2 driver, from
      Hariprasad Kelam.

  28) Fix being unable to change MTU of dwmac-sun8i devices due to lack
      of fifo sizes, from Corentin Labbe.

  29) DMA use after free in r8169 with WoL, fom Heiner Kallweit.

  30) Mismatched prototypes in isdn-capi, from Arnd Bergmann.

  31) Fix psample UAPI breakage, from Ido Schimmel"

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (171 commits)
  psample: Fix user API breakage
  math: Export mul_u64_u64_div_u64
  ch_ktls: fix enum-conversion warning
  octeontx2-af: Fix memory leak of object buf
  ptp_qoriq: fix overflow in ptp_qoriq_adjfine() u64 calcalation
  net: bridge: don't notify switchdev for local FDB addresses
  net/sched: act_ct: clear post_ct if doing ct_clear
  net: dsa: don't assign an error value to tag_ops
  isdn: capi: fix mismatched prototypes
  net/mlx5: SF, do not use ecpu bit for vhca state processing
  net/mlx5e: Fix division by 0 in mlx5e_select_queue
  net/mlx5e: Fix error path for ethtool set-priv-flag
  net/mlx5e: Offload tuple rewrite for non-CT flows
  net/mlx5e: Allow to match on MPLS parameters only for MPLS over UDP
  net/mlx5: Add back multicast stats for uplink representor
  net: ipconfig: ic_dev can be NULL in ic_close_devs
  MAINTAINERS: Combine "QLOGIC QLGE 10Gb ETHERNET DRIVER" sections into one
  docs: networking: Fix a typo
  r8169: fix DMA being used after buffer free if WoL is enabled
  net: ipa: fix init header command validation
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>mm/writeback: Add wait_on_page_writeback_killable</title>
<updated>2021-03-23T20:54:29+00:00</updated>
<author>
<name>Matthew Wilcox (Oracle)</name>
<email>willy@infradead.org</email>
</author>
<published>2021-03-20T05:40:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e5dbd33218bd8d87ab69f730ab90aed5fab7eb26'/>
<id>e5dbd33218bd8d87ab69f730ab90aed5fab7eb26</id>
<content type='text'>
This is the killable version of wait_on_page_writeback.

Signed-off-by: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Tested-by: kafs-testing@auristor.com
cc: linux-afs@lists.infradead.org
cc: linux-mm@kvack.org
Link: https://lore.kernel.org/r/20210320054104.1300774-3-willy@infradead.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This is the killable version of wait_on_page_writeback.

Signed-off-by: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Tested-by: kafs-testing@auristor.com
cc: linux-afs@lists.infradead.org
cc: linux-mm@kvack.org
Link: https://lore.kernel.org/r/20210320054104.1300774-3-willy@infradead.org
</pre>
</div>
</content>
</entry>
<entry>
<title>fs/cachefiles: Remove wait_bit_key layout dependency</title>
<updated>2021-03-23T20:54:29+00:00</updated>
<author>
<name>Matthew Wilcox (Oracle)</name>
<email>willy@infradead.org</email>
</author>
<published>2021-03-20T05:40:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=39f985c8f667c80a3d1eb19d31138032fa36b09e'/>
<id>39f985c8f667c80a3d1eb19d31138032fa36b09e</id>
<content type='text'>
Cachefiles was relying on wait_page_key and wait_bit_key being the
same layout, which is fragile.  Now that wait_page_key is exposed in
the pagemap.h header, we can remove that fragility

A comment on the need to maintain structure layout equivalence was added by
Linus[1] and that is no longer applicable.

Fixes: 62906027091f ("mm: add PageWaiters indicating tasks are waiting for a page bit")
Signed-off-by: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Tested-by: kafs-testing@auristor.com
cc: linux-cachefs@redhat.com
cc: linux-mm@kvack.org
Link: https://lore.kernel.org/r/20210320054104.1300774-2-willy@infradead.org/
Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3510ca20ece0150af6b10c77a74ff1b5c198e3e2 [1]
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Cachefiles was relying on wait_page_key and wait_bit_key being the
same layout, which is fragile.  Now that wait_page_key is exposed in
the pagemap.h header, we can remove that fragility

A comment on the need to maintain structure layout equivalence was added by
Linus[1] and that is no longer applicable.

Fixes: 62906027091f ("mm: add PageWaiters indicating tasks are waiting for a page bit")
Signed-off-by: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Tested-by: kafs-testing@auristor.com
cc: linux-cachefs@redhat.com
cc: linux-mm@kvack.org
Link: https://lore.kernel.org/r/20210320054104.1300774-2-willy@infradead.org/
Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3510ca20ece0150af6b10c77a74ff1b5c198e3e2 [1]
</pre>
</div>
</content>
</entry>
</feed>
