The kernel test robot flagged a recursive lock as a result of a conversion
from kmap_atomic() to kmap_local_folio()[Link]

The cause was due to the code depending on the kmap_atomic() side effect
of disabling page faults.  In that case the code expects the fault to fail
and take the fallback case.

git archaeology implied that the recursion may not be an actual bug.[1]
However, depending on the implementation of the mmap_lock and the
condition of the call there may still be a deadlock.[2] So this is not
purely a lockdep issue.  Considering a single threaded call stack there
are 3 options.

	1) Different mm's are in play (no issue)
	2) Readlock implementation is recursive and same mm is in play
	   (no issue)
	3) Readlock implementation is _not_ recursive (issue)

The mmap_lock is recursive so with a single thread there is no issue.

However, Matthew pointed out a deadlock scenario when you consider
additional process' and threads thusly.

"The readlock implementation is only recursive if nobody else has taken a
write lock.  If you have a multithreaded process, one of the other threads
can call mmap() and that will prevent recursion (due to fairness).  Even
if it's a different process that you're trying to acquire the mmap read
lock on, you can still get into a deadly embrace.  eg:

process A thread 1 takes read lock on own mmap_lock
process A thread 2 calls mmap, blocks taking write lock
process B thread 1 takes page fault, read lock on own mmap lock
process B thread 2 calls mmap, blocks taking write lock
process A thread 1 blocks taking read lock on process B
process B thread 1 blocks taking read lock on process A

Now all four threads are blocked waiting for each other."

Regardless using pagefault_disable() ensures that no matter what locking
implementation is used a deadlock will not occur.  Add an explicit
pagefault_disable() and a big comment to explain this for future souls
looking at this code.

[1] https://lore.kernel.org/all/Y1MymJ%2FINb45AdaY@iweiny-desk3/
[2] https://lore.kernel.org/lkml/Y1bXBtGTCym77%2FoD@casper.infradead.org/

Link: https://lkml.kernel.org/r/20221025220108.2366043-1-ira.weiny@intel.com
Link: https://lore.kernel.org/r/202210211215.9dc6efb5-yujie.liu@intel.com
Fixes: 7a7256d5 ("shmem: convert shmem_mfill_atomic_pte() to use a folio")
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Reported-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reported-by: kernel test robot <yujie.liu@intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

kmap() and kmap_atomic() are being deprecated in favor of
kmap_local_page() which is appropriate for any thread local context.[1]

A recent locking bug report with userfaultfd showed that the conversion of
the kmap_atomic()'s in those code flows requires care with regard to the
prevention of deadlock.[2]

git archaeology implied that the recursion may not be an actual bug.[3]
However, depending on the implementation of the mmap_lock and the
condition of the call there may still be a deadlock.[4] So this is not
purely a lockdep issue.  Considering a single threaded call stack there
are 3 options.

	1) Different mm's are in play (no issue)
	2) Readlock implementation is recursive and same mm is in play
	   (no issue)
	3) Readlock implementation is _not_ recursive (issue)

The mmap_lock is recursive so with a single thread there is no issue.

However, Matthew pointed out a deadlock scenario when you consider
additional process' and threads thusly.

"The readlock implementation is only recursive if nobody else has taken a
write lock.  If you have a multithreaded process, one of the other threads
can call mmap() and that will prevent recursion (due to fairness).  Even
if it's a different process that you're trying to acquire the mmap read
lock on, you can still get into a deadly embrace.  eg:

process A thread 1 takes read lock on own mmap_lock
process A thread 2 calls mmap, blocks taking write lock
process B thread 1 takes page fault, read lock on own mmap lock
process B thread 2 calls mmap, blocks taking write lock
process A thread 1 blocks taking read lock on process B
process B thread 1 blocks taking read lock on process A

Now all four threads are blocked waiting for each other."

Regardless using pagefault_disable() ensures that no matter what locking
implementation is used a deadlock will not occur.

Complete kmap conversion in userfaultfd by replacing the kmap() and
kmap_atomic() calls with kmap_local_page().  When replacing the
kmap_atomic() call ensure page faults continue to be disabled to support
the correct fall back behavior and add a comment to inform future souls of
the requirement.

[1] https://lore.kernel.org/all/20220813220034.806698-1-ira.weiny@intel.com/
[2] https://lore.kernel.org/all/Y1Mh2S7fUGQ%2FiKFR@iweiny-desk3/
[3] https://lore.kernel.org/all/Y1MymJ%2FINb45AdaY@iweiny-desk3/
[4] https://lore.kernel.org/lkml/Y1bXBtGTCym77%2FoD@casper.infradead.org/

[ira.weiny@intel.com: v2]
  Link: https://lkml.kernel.org/r/20221025220136.2366143-1-ira.weiny@intel.com
Link: https://lkml.kernel.org/r/20221024043452.1491677-1-ira.weiny@intel.comSigned-off-by: Ira Weiny <ira.weiny@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Ensure that KMSAN builds replace memset/memcpy/memmove calls with the
respective __msan_XXX functions, and that none of the macros are redefined
twice.  This should allow building kernel with both CONFIG_KMSAN and
CONFIG_FORTIFY_SOURCE.

Link: https://lkml.kernel.org/r/20221024212144.2852069-5-glider@google.com
Link: https://github.com/google/kmsan/issues/89Signed-off-by: Alexander Potapenko <glider@google.com>
Reported-by: Tamas K Lengyel <tamas.lengyel@zentific.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

User access macros must ensure their arguments are evaluated only once if
they are used more than once in the macro body.  Adding
instrument_put_user() to __put_user_size() resulted in double evaluation
of the `ptr` argument, which led to correctness issues when performing
e.g.  unsafe_put_user(..., p++, ...).

To fix those issues, evaluate the `ptr` argument of __put_user_size() at
the beginning of the macro.

Link: https://lkml.kernel.org/r/20221024212144.2852069-4-glider@google.com
Fixes: 888f84a6 ("x86: asm: instrument usercopy in get_user() and put_user()")
Signed-off-by: Alexander Potapenko <glider@google.com>
Reported-by: youling257 <youling257@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

KMSAN adds a lot of instrumentation to the code, which results in
increased stack usage (up to 2048 bytes and more in some cases).  It's
hard to predict how big the stack frames can be, so we disable the
warnings for KMSAN instead.

Link: https://lkml.kernel.org/r/20221024212144.2852069-3-glider@google.com
Link: https://github.com/google/kmsan/issues/89Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

The stand-alone purgatory.ro does not contain the KMSAN runtime, therefore
it can't be built with KMSAN compiler instrumentation.

Link: https://lkml.kernel.org/r/20221024212144.2852069-2-glider@google.com
Link: https://github.com/google/kmsan/issues/89Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Certain modules call copy_user_highpage(), which calls
kmsan_copy_page_meta() under KMSAN, so we need to export the latter.

Link: https://lkml.kernel.org/r/20221024212144.2852069-1-glider@google.com
Link: https://github.com/google/kmsan/issues/89
Fixes: b073d7f8 ("mm: kmsan: maintain KMSAN metadata for page operations")
Signed-off-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

During THP migration, if THPs are not migrated but they are split and all
subpages are migrated successfully, migrate_pages() will still return the
number of THP pages that were not migrated.  This will confuse the callers
of migrate_pages().  For example, the longterm pinning will failed though
all pages are migrated successfully.

Thus we should return 0 to indicate that all pages are migrated in this
case

Link: https://lkml.kernel.org/r/de386aa864be9158d2f3b344091419ea7c38b2f7.1666599848.git.baolin.wang@linux.alibaba.com
Fixes: b5bade97 ("mm: migrate: fix the return value of migrate_pages()")
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

We used to have a report that pte-marker code can be reached even when
uffd-wp is not compiled in for file memories, here:

https://lore.kernel.org/all/YzeR+R6b4bwBlBHh@x1n/T/#u

I just got time to revisit this and found that the root cause is we simply
messed up with the vma check, so that for !PTE_MARKER_UFFD_WP system, we
will allow UFFDIO_REGISTER of MINOR & WP upon shmem as the check was
wrong:

    if (vm_flags & VM_UFFD_MINOR)
        return is_vm_hugetlb_page(vma) || vma_is_shmem(vma);

Where we'll allow anything to pass on shmem as long as minor mode is
requested.

Axel did it right when introducing minor mode but I messed it up in
b1f9e876 when moving code around.  Fix it.

Link: https://lkml.kernel.org/r/20221024193336.1233616-1-peterx@redhat.com
Link: https://lkml.kernel.org/r/20221024193336.1233616-2-peterx@redhat.com
Fixes: b1f9e876 ("mm/uffd: enable write protection for shmem & hugetlbfs")
Signed-off-by: Peter Xu <peterx@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Although page allocation always clears page->private in the first page or
head page of an allocation, it has never made a point of clearing
page->private in the tails (though 0 is often what is already there).

But now commit 71e2d666 ("mm/huge_memory: do not clobber swp_entry_t
during THP split") issues a warning when page_tail->private is found to be
non-0 (unless it's swapcache).

Change that warning to dump page_tail (which also dumps head), instead of
just the head: so far we have seen dead000000000122, dead000000000003,
dead000000000001 or 0000000000000002 in the raw output for tail private.

We could just delete the warning, but today's consensus appears to want
page->private to be 0, unless there's a good reason for it to be set: so
now clear it in prep_compound_tail() (more general than just for THP; but
not for high order allocation, which makes no pass down the tails).

Link: https://lkml.kernel.org/r/1c4233bb-4e4d-5969-fbd4-96604268a285@google.com
Fixes: 71e2d666 ("mm/huge_memory: do not clobber swp_entry_t during THP split")
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

A common use case for hugetlbfs is for the application to create
memory pools backed by huge pages, which then get handed over to
some malloc library (eg. jemalloc) for further management.

That malloc library may be doing MADV_DONTNEED calls on memory
that is no longer needed, expecting those calls to happen on
PAGE_SIZE boundaries.

However, currently the MADV_DONTNEED code rounds up any such
requests to HPAGE_PMD_SIZE boundaries. This leads to undesired
outcomes when jemalloc expects a 4kB MADV_DONTNEED, but 2MB of
memory get zeroed out, instead.

Use of pre-built shared libraries means that user code does not
always know the page size of every memory arena in use.

Avoid unexpected data loss with MADV_DONTNEED by rounding up
only to PAGE_SIZE (in do_madvise), and rounding down to huge
page granularity.

That way programs will only get as much memory zeroed out as
they requested.

Link: https://lkml.kernel.org/r/20221021192805.366ad573@imladris.surriel.com
Fixes: 90e7e7f5 ("mm: enable MADV_DONTNEED for hugetlb mappings")
Signed-off-by: Rik van Riel <riel@surriel.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

When !CONFIG_VM_BUG_ON, there is warning of
clang-analyzer-deadcode.DeadStores:
Value stored to 'mt' during its initialization is never read.

Link: https://lkml.kernel.org/r/20221021101555.7992-2-quic_aiquny@quicinc.comSigned-off-by: Maria Yu <quic_aiquny@quicinc.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Doug Berger <opendmb@gmail.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

fs/ext4/super.c:1744:19: warning: 'deprecated_msg' defined but not used [-Wunused-const-variable=]
Reported-by: kernel test robot <lkp@intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

These percpu counters are referenced in free_ipcs->freeque, so destroy
them later.

Fixes: 72d1e611 ("ipc/msg: mitigate the lock contention with percpu counter")
Reported-by: syzbot+96e659d35b9d6b541152@syzkaller.appspotmail.com
Tested-by: Mark Rutland <mark.rutland@arm.com>
Cc: Jiebin Sun <jiebin.sun@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

In sysfs, we use attribute name "cpumap" or "cpus" for cpu mask and
"cpulist" or "cpus_list" for cpu list.  For example, in my system,

 $ cat /sys/devices/system/node/node0/cpumap
 f,ffffffff
 $ cat /sys/devices/system/cpu/cpu2/topology/core_cpus
 0,00100004
 $ cat cat /sys/devices/system/node/node0/cpulist
 0-35
 $ cat /sys/devices/system/cpu/cpu2/topology/core_cpus_list
 2,20

It looks reasonable to use "nodemap" for node mask and "nodelist" for
node list.  So, rename the attribute to follow the naming convention.

Link: https://lkml.kernel.org/r/20221020015122.290097-1-ying.huang@intel.com
Fixes: 9832fb87 ("mm/demotion: expose memory tier details via sysfs")
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Acked-by: Wei Xu <weixugc@google.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Bharata B Rao <bharata@amd.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Hesham Almatary <hesham.almatary@huawei.com>
Cc: Jagdish Gediya <jvgediya.oss@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tim Chen <tim.c.chen@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Github deprecated the git:// links about a year ago, so let's move to the
https:// URLs instead.

Link: https://lkml.kernel.org/r/20221020024255.5000-1-konishi.ryusuke@gmail.com
Link: https://github.blog/2021-09-01-improving-git-protocol-security-github/
Link: https://lkml.kernel.org/r/20221013214638.30933-1-palmer@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Commit 6edda04c ("mm/kmemleak: prevent soft lockup in first object
iteration loop of kmemleak_scan()") adds cond_resched() in the first
object iteration loop of kmemleak_scan().  However, it turns that the 2nd
objection iteration loop can still cause soft lockup to happen in some
cases.  So add a cond_resched() call in the 2nd and 3rd loops as well to
prevent that and for completeness.

Link: https://lkml.kernel.org/r/20221020175619.366317-1-longman@redhat.com
Fixes: 6edda04c ("mm/kmemleak: prevent soft lockup in first object iteration loop of kmemleak_scan()")
Signed-off-by: Waiman Long <longman@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Fix a buffer release race condition, where the error value was used after
release.

Link: https://lkml.kernel.org/r/20221020223616.7571-4-phillip@squashfs.org.uk
Fixes: b09a7a03 ("squashfs: support reading fragments in readahead call")
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
Reported-by: Marc Miltenberger <marcmiltenberger@gmail.com>
Cc: Dimitri John Ledkov <dimitri.ledkov@canonical.com>
Cc: Hsin-Yi Wang <hsinyi@chromium.org>
Cc: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Cc: Slade Watkins <srw@sladewatkins.net>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

The readahead code will try to extend readahead to the entire size of the
Squashfs data block.

But, it didn't take into account that the last block at the end of the
file may not be a whole block.  In this case, the code would extend
readahead to beyond the end of the file, leaving trailing pages.

Fix this by only requesting the expected number of pages.

Link: https://lkml.kernel.org/r/20221020223616.7571-3-phillip@squashfs.org.uk
Fixes: 8fc78b6f ("squashfs: implement readahead")
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
Reported-by: Marc Miltenberger <marcmiltenberger@gmail.com>
Cc: Dimitri John Ledkov <dimitri.ledkov@canonical.com>
Cc: Hsin-Yi Wang <hsinyi@chromium.org>
Cc: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Cc: Slade Watkins <srw@sladewatkins.net>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Patch series "squashfs: fix some regressions introduced in the readahead
code".

This patchset fixes 3 regressions introduced by the recent readahead code
changes.  The first regression is causing "snaps" to randomly fail after a
couple of hours or days, which how the regression came to light.


This patch (of 3):

If a file isn't a whole multiple of the page size, the last page will have
trailing bytes unfilled.

There was a mistake in the readahead code which did this.  In particular
it incorrectly assumed that the last page in the readahead page array
(page[nr_pages - 1]) will always contain the last page in the block, which
if we're at file end, will be the page that needs to be zero filled.

But the readahead code may not return the last page in the block, which
means it is unmapped and will be skipped by the decompressors (a temporary
buffer used).

In this case the zero filling code will zero out the wrong page, leading
to data corruption.

Fix this by by extending the "page actor" to return the last page if
present, or NULL if a temporary buffer was used.

Link: https://lkml.kernel.org/r/20221020223616.7571-1-phillip@squashfs.org.uk
Link: https://lkml.kernel.org/r/20221020223616.7571-2-phillip@squashfs.org.uk
Fixes: 8fc78b6f ("squashfs: implement readahead")
Link: https://lore.kernel.org/lkml/b0c258c3-6dcf-aade-efc4-d62a8b3a1ce2@alu.unizg.hr/Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Reported-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Tested-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Tested-by: Slade Watkins <srw@sladewatkins.net>
Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
Reported-by: Marc Miltenberger <marcmiltenberger@gmail.com>
Cc: Dimitri John Ledkov <dimitri.ledkov@canonical.com>
Cc: Hsin-Yi Wang <hsinyi@chromium.org>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Commit 16ce101d ("mm/memory.c: fix race when faulting a device private
page") changed the migrate_to_ram() callback to take a reference on the
device page to ensure it can't be freed while handling the fault. 
Unfortunately the corresponding update to Nouveau to accommodate this
change was inadvertently dropped from that patch causing GPU to CPU
migration to fail so add it here.

Link: https://lkml.kernel.org/r/20221019122934.866205-1-apopple@nvidia.com
Fixes: 16ce101d ("mm/memory.c: fix race when faulting a device private page")
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

The following has been observed when running stressng mmap since commit
b653db77 ("mm: Clear page->private when splitting or migrating a page")

   watchdog: BUG: soft lockup - CPU#75 stuck for 26s! [stress-ng:9546]
   CPU: 75 PID: 9546 Comm: stress-ng Tainted: G            E      6.0.0-revert-b653db77-fix+ #29 0357d79b60fb09775f678e4f3f64ef0579ad1374
   Hardware name: SGI.COM C2112-4GP3/X10DRT-P-Series, BIOS 2.0a 05/09/2016
   RIP: 0010:xas_descend+0x28/0x80
   Code: cc cc 0f b6 0e 48 8b 57 08 48 d3 ea 83 e2 3f 89 d0 48 83 c0 04 48 8b 44 c6 08 48 89 77 18 48 89 c1 83 e1 03 48 83 f9 02 75 08 <48> 3d fd 00 00 00 76 08 88 57 12 c3 cc cc cc cc 48 c1 e8 02 89 c2
   RSP: 0018:ffffbbf02a2236a8 EFLAGS: 00000246
   RAX: ffff9cab7d6a0002 RBX: ffffe04b0af88040 RCX: 0000000000000002
   RDX: 0000000000000030 RSI: ffff9cab60509b60 RDI: ffffbbf02a2236c0
   RBP: 0000000000000000 R08: ffff9cab60509b60 R09: ffffbbf02a2236c0
   R10: 0000000000000001 R11: ffffbbf02a223698 R12: 0000000000000000
   R13: ffff9cab4e28da80 R14: 0000000000039c01 R15: ffff9cab4e28da88
   FS:  00007fab89b85e40(0000) GS:ffff9cea3fcc0000(0000) knlGS:0000000000000000
   CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
   CR2: 00007fab84e00000 CR3: 00000040b73a4003 CR4: 00000000003706e0
   DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
   DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
   Call Trace:
    <TASK>
    xas_load+0x3a/0x50
    __filemap_get_folio+0x80/0x370
    ? put_swap_page+0x163/0x360
    pagecache_get_page+0x13/0x90
    __try_to_reclaim_swap+0x50/0x190
    scan_swap_map_slots+0x31e/0x670
    get_swap_pages+0x226/0x3c0
    folio_alloc_swap+0x1cc/0x240
    add_to_swap+0x14/0x70
    shrink_page_list+0x968/0xbc0
    reclaim_page_list+0x70/0xf0
    reclaim_pages+0xdd/0x120
    madvise_cold_or_pageout_pte_range+0x814/0xf30
    walk_pgd_range+0x637/0xa30
    __walk_page_range+0x142/0x170
    walk_page_range+0x146/0x170
    madvise_pageout+0xb7/0x280
    ? asm_common_interrupt+0x22/0x40
    madvise_vma_behavior+0x3b7/0xac0
    ? find_vma+0x4a/0x70
    ? find_vma+0x64/0x70
    ? madvise_vma_anon_name+0x40/0x40
    madvise_walk_vmas+0xa6/0x130
    do_madvise+0x2f4/0x360
    __x64_sys_madvise+0x26/0x30
    do_syscall_64+0x5b/0x80
    ? do_syscall_64+0x67/0x80
    ? syscall_exit_to_user_mode+0x17/0x40
    ? do_syscall_64+0x67/0x80
    ? syscall_exit_to_user_mode+0x17/0x40
    ? do_syscall_64+0x67/0x80
    ? do_syscall_64+0x67/0x80
    ? common_interrupt+0x8b/0xa0
    entry_SYSCALL_64_after_hwframe+0x63/0xcd

The problem can be reproduced with the mmtests config
config-workload-stressng-mmap.  It does not always happen and when it
triggers is variable but it has happened on multiple machines.

The intent of commit b653db77 patch was to avoid the case where
PG_private is clear but folio->private is not-NULL.  However, THP tail
pages uses page->private for "swp_entry_t if folio_test_swapcache()" as
stated in the documentation for struct folio.  This patch only clobbers
page->private for tail pages if the head page was not in swapcache and
warns once if page->private had an unexpected value.

Link: https://lkml.kernel.org/r/20221019134156.zjyyn5aownakvztf@techsingularity.net
Fixes: b653db77 ("mm: Clear page->private when splitting or migrating a page")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Brian Foster <bfoster@redhat.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Oleksandr Natalenko <oleksandr@natalenko.name>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

The hugetlb vma_lock structure hangs off the vm_private_data pointer of
sharable hugetlb vmas.  The structure is vma specific and can not be
shared between vmas.  At fork and various other times, vmas are duplicated
via vm_area_dup().  When this happens, the pointer in the newly created
vma must be cleared and the structure reallocated.  Two hugetlb specific
routines deal with this hugetlb_dup_vma_private and hugetlb_vm_op_open. 
Both routines are called for newly created vmas.  hugetlb_dup_vma_private
would always clear the pointer and hugetlb_vm_op_open would allocate the
new vms_lock structure.  This did not work in the case of this calling
sequence pointed out in [1].

  move_vma
    copy_vma
      new_vma = vm_area_dup(vma);
      new_vma->vm_ops->open(new_vma); --> new_vma has its own vma lock.
    is_vm_hugetlb_page(vma)
      clear_vma_resv_huge_pages
        hugetlb_dup_vma_private --> vma->vm_private_data is set to NULL

When clearing hugetlb_dup_vma_private we actually leak the associated
vma_lock structure.

The vma_lock structure contains a pointer to the associated vma.  This
information can be used in hugetlb_dup_vma_private and hugetlb_vm_op_open
to ensure we only clear the vm_private_data of newly created (copied)
vmas.  In such cases, the vma->vma_lock->vma field will not point to the
vma.

Update hugetlb_dup_vma_private and hugetlb_vm_op_open to not clear
vm_private_data if vma->vma_lock->vma == vma.  Also, log a warning if
hugetlb_vm_op_open ever encounters the case where vma_lock has already
been correctly allocated for the vma.

[1] https://lore.kernel.org/linux-mm/5154292a-4c55-28cd-0935-82441e512fc3@huawei.com/

Link: https://lkml.kernel.org/r/20221019201957.34607-1-mike.kravetz@oracle.com
Fixes: 131a79b4 ("hugetlb: fix vma lock handling during split vma and range unmapping")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: James Houghton <jthoughton@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Prakash Sangappa <prakash.sangappa@oracle.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Try to avoid using the left over split page on the next request for a page
by calling __free_pages_ok() with FPI_TO_TAIL.  This increases the
potential of defragmenting memory when it's used for a short period of
time.

Link: https://lkml.kernel.org/r/20220531185626.yvlmymbxyoe5vags@revolverSigned-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Suggested-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

/proc/pid/smaps_rollup showed 0 kB for everything: now find first vma.

Link: https://lkml.kernel.org/r/3011bee7-182-97a2-1083-d5f5b688e54b@google.com
Fixes: c4c84f06 ("fs/proc/task_mmu: stop using linked list and highest_vm_end")
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

The h->*_huge_pages counters are protected by the hugetlb_lock, but
alloc_huge_page has a corner case where it can decrement the counter
outside of the lock.

This could lead to a corrupted value of h->resv_huge_pages, which we have
observed on our systems.

Take the hugetlb_lock before decrementing h->resv_huge_pages to avoid a
potential race.

Link: https://lkml.kernel.org/r/20221017202505.0e6a4fcd@imladris.surriel.com
Fixes: a88c7695 ("mm: hugetlb: fix hugepage memory leak caused by wrong reserve count")
Signed-off-by: Rik van Riel <riel@surriel.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Glen McCready <gkmccready@meta.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mmap should return the start address of newly mapped area when successful.
On a successful merge of a VMA, the return address was changed and thus
was violating that expectation from userspace.

This is a restoration of functionality provided by 309d08d9
(mm/mmap.c: fix mmap return value when vma is merged after call_mmap()). 
For completeness of fixing MAP_FIXED, implement the comments from the
previous discussion to never update the address and fail if the address
changes.  Leaving the error as a WARN_ON() to avoid crashing the kernel.

Link: https://lkml.kernel.org/r/20221018191613.4133459-1-Liam.Howlett@oracle.com
Link: https://lore.kernel.org/all/Y06yk66SKxlrwwfb@lakrids/
Link: https://lore.kernel.org/all/20201203085350.22624-1-liuzixian4@huawei.com/
Fixes: 4dd1b841 ("mm/mmap: use advanced maple tree API for mmap_region()")
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reported-by: Mark Rutland <mark.rutland@arm.com>
Cc: Liu Zixian <liuzixian4@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

The code is OK, but it fools gcc.

mm/mmap.c:802 __vma_adjust() error: uninitialized symbol 'next_next'.

Fixes: 524e00b3 ("mm: remove rb tree.")
Reported-by: kernel test robot <lkp@intel.com>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

A memory leak in hugetlb_reserve_pages was reported in [1].  The root
cause was traced to an error path in mmap_region when mas_preallocate()
fails.  In this case, the vma is freed after a successful call to
filesystem specific mmap.  The hugetlbfs mmap routine may allocate data
structures pointed to by m_private_data.  These need to be cleaned up by
the hugetlb vm_ops->close() routine.

The same issue was addressed by commit deb0f656 ("mm/mmap: undo
->mmap() when arch_validate_flags() fails") for the arch_validate_flags()
test.  Go to the same close_and_free_vma label if mas_preallocate() fails.

[1] https://lore.kernel.org/linux-mm/CAKXUXMxf7OiCwbxib7MwfR4M1b5+b3cNTU7n5NV9Zm4967=FPQ@mail.gmail.com/

Link: https://lkml.kernel.org/r/20221018024945.415036-1-mike.kravetz@oracle.com
Fixes: d4af56c5 ("mm: start tracking VMAs with maple tree")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reported-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Carlos Llamas <cmllamas@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

There is a spelling mistake in a Kconfig description.  Fix it.

Link: https://lkml.kernel.org/r/20221007204339.2757753-1-colin.i.king@gmail.comSigned-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

In ocfs2_mknod(), if error occurs after dinode successfully allocated,
ocfs2 i_links_count will not be 0.

So even though we clear inode i_nlink before iput in error handling, it
still won't wipe inode since we'll refresh inode from dinode during inode
lock.  So just like clear inode i_nlink, we clear ocfs2 i_links_count as
well.  Also do the same change for ocfs2_symlink().

Link: https://lkml.kernel.org/r/20221017130227.234480-2-joseph.qi@linux.alibaba.comSigned-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reported-by: Yan Wang <wangyan122@huawei.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Commit b1529a41 "ocfs2: should reclaim the inode if
'__ocfs2_mknod_locked' returns an error" tried to reclaim the claimed
inode if __ocfs2_mknod_locked() fails later.  But this introduce a race,
the freed bit may be reused immediately by another thread, which will
update dinode, e.g.  i_generation.  Then iput this inode will lead to BUG:
inode->i_generation != le32_to_cpu(fe->i_generation)

We could make this inode as bad, but we did want to do operations like
wipe in some cases.  Since the claimed inode bit can only affect that an
dinode is missing and will return back after fsck, it seems not a big
problem.  So just leave it as is by revert the reclaim logic.

Link: https://lkml.kernel.org/r/20221017130227.234480-1-joseph.qi@linux.alibaba.com
Fixes: b1529a41 ("ocfs2: should reclaim the inode if '__ocfs2_mknod_locked' returns an error")
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reported-by: Yan Wang <wangyan122@huawei.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Starting with GCC 12.1, the created .gcda format can't be read by gcov
tool.  There are 2 significant changes to the .gcda file format that
need to be supported:

a) [gcov: Use system IO buffering]
   (23eb66d1d46a34cb28c4acbdf8a1deb80a7c5a05) changed that all sizes in
   the format are in bytes and not in words (4B)

b) [gcov: make profile merging smarter]
   (72e0c742bd01f8e7e6dcca64042b9ad7e75979de) add a new checksum to the
   file header.

Tested with GCC 7.5, 10.4, 12.2 and the current master.

Link: https://lkml.kernel.org/r/624bda92-f307-30e9-9aaa-8cc678b2dfb2@suse.czSigned-off-by: Martin Liska <mliska@suse.cz>
Tested-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Inside the zs_destroy_pool() function, there can still be NULL size_class
pointers: if when the next size_class is allocated, inside
zs_create_pool() function, kzalloc will return NULL and handling the error
condition, zs_create_pool() will call zs_destroy_pool().

Link: https://lkml.kernel.org/r/20221013112825.61869-1-avromanov@sberdevices.ru
Fixes: f24263a5 ("zsmalloc: remove unnecessary size_class NULL check")
Signed-off-by: Alexey Romanov <avromanov@sberdevices.ru>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Fuzzing produced an invalid argument to vma_merge() which was caught by
the newly added verification of the number of VMAs being removed on
process exit.  Analyzing the failure eventually resulted in finding an
issue with the search of a VMA that started at address 0, which caused an
underflow and thus the loss of many VMAs being tracked in the tree.  Fix
the underflow by changing the search of the maple tree to use the start
address directly.

Link: https://lkml.kernel.org/r/20221015021135.2816178-1-Liam.Howlett@oracle.com
Fixes: 66850be5 ("mm/mempolicy: use vma iterator & maple state instead of vma linked list")
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
  Link: https://lore.kernel.org/r/202210052318.5ad10912-oliver.sang@intel.com
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Update my email address for old entry and add a new entry for my
contribution while working with arm to continue support that work.

Link: https://lkml.kernel.org/r/20221014141016.539625-1-qyousef@layalina.ioSigned-off-by: Qais Yousef <qyousef@layalina.io>
Acked-by: Qais Yousef <qais.yousef@arm.com>
Acked-by: Qais Yousef <qsyousef@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

My time at Oracle is ending at the end of the month.  Update my email
address accordingly.

Link: https://lkml.kernel.org/r/Y0a+6+5SHMdvUnpg@kiliSigned-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>