mm: simplify compat numa syscalls

The compat implementations for mbind, get_mempolicy, set_mempolicy and
migrate_pages are just there to handle the subtly different layout of
bitmaps on 32-bit hosts.

The compat implementation however lacks some of the checks that are
present in the native one, in particular for checking that the extra bits
are all zero when user space has a larger mask size than the kernel.
Worse, those extra bits do not get cleared when copying in or out of the
kernel, which can lead to incorrect data as well.

Unify the implementation to handle the compat bitmap layout directly in
the get_nodes() and copy_nodes_to_user() helpers.  Splitting out the
get_bitmap() helper from get_nodes() also helps readability of the native
case.

On x86, two additional problems are addressed by this: compat tasks can
pass a bitmap at the end of a mapping, causing a fault when reading across
the page boundary for a 64-bit word.  x32 tasks might also run into
problems with get_mempolicy corrupting data when an odd number of 32-bit
words gets passed.

On parisc the migrate_pages() system call apparently had the wrong calling
convention, as big-endian architectures expect the words inside of a
bitmap to be swapped.  This is not a problem though since parisc has no
NUMA support.

Link: https://lkml.kernel.org/r/20210727144859.4150043-5-arnd@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

mm: simplify compat_sys_move_pages

The compat move_pages() implementation uses compat_alloc_user_space() for
converting the pointer array.  Moving the compat handling into the
function itself is a bit simpler and lets us avoid the
compat_alloc_user_space() call.

Link: https://lkml.kernel.org/r/20210727144859.4150043-4-arnd@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

kexec: avoid compat_alloc_user_space

kimage_alloc_init() expects a __user pointer, so compat_sys_kexec_load()
uses compat_alloc_user_space() to convert the layout and put it back onto
the user space caller stack.

Moving the user space access into the syscall handler directly actually
makes the code simpler, as the conversion for compat mode can now be done
on kernel memory.

Link: https://lkml.kernel.org/r/20210727144859.4150043-3-arnd@kernel.org
Link: https://lore.kernel.org/lkml/YPbtsU4GX6PL7%2F42@infradead.org/
Link: https://lore.kernel.org/lkml/m1y2cbzmnw.fsf@fess.ebiederm.org/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Co-developed-by: Eric Biederman <ebiederm@xmission.com>
Co-developed-by: Christoph Hellwig <hch@infradead.org>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

kexec: move locking into do_kexec_load

Patch series "compat: remove compat_alloc_user_space", v5.

Going through compat_alloc_user_space() to convert indirect system call
arguments tends to add complexity compared to handling the native and
compat logic in the same code.

This patch (of 6):

The locking is the same between the native and compat version of
sys_kexec_load(), so it can be done in the common implementation to reduce
duplication.

Link: https://lkml.kernel.org/r/20210727144859.4150043-1-arnd@kernel.org
Link: https://lkml.kernel.org/r/20210727144859.4150043-2-arnd@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Co-developed-by: Eric Biederman <ebiederm@xmission.com>
Co-developed-by: Christoph Hellwig <hch@infradead.org>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

scripts: check_extable: fix typo in user error message

Fix typo ("and" should be "an") in an error message.

Link: https://lkml.kernel.org/r/20210727002943.29774-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

mm/vmalloc: add __alloc_size attributes for better bounds checking

As already done in GrapheneOS, add the __alloc_size attribute for
appropriate vmalloc allocator interfaces, to provide additional hinting
for better bounds checking, assisting CONFIG_FORTIFY_SOURCE and other
compiler optimizations.

Link: https://lkml.kernel.org/r/20210818214021.2476230-8-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Co-developed-by: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Daniel Micay <danielmicay@gmail.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

percpu: add __alloc_size attributes for better bounds checking

As already done in GrapheneOS, add the __alloc_size attribute for
appropriate percpu allocator interfaces, to provide additional hinting for
better bounds checking, assisting CONFIG_FORTIFY_SOURCE and other compiler
optimizations.

Link: https://lkml.kernel.org/r/20210818214021.2476230-7-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Co-developed-by: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Daniel Micay <danielmicay@gmail.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

mm/page_alloc: add __alloc_size attributes for better bounds checking

As already done in GrapheneOS, add the __alloc_size attribute for
appropriate page allocator interfaces, to provide additional hinting for
better bounds checking, assisting CONFIG_FORTIFY_SOURCE and other compiler
optimizations.

Link: https://lkml.kernel.org/r/20210818214021.2476230-6-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Co-developed-by: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Daniel Micay <danielmicay@gmail.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

slab: add __alloc_size attributes for better bounds checking

As already done in GrapheneOS, add the __alloc_size attribute for regular
kmalloc interfaces, to provide additional hinting for better bounds
checking, assisting CONFIG_FORTIFY_SOURCE and other compiler
optimizations.

Link: https://lkml.kernel.org/r/20210818214021.2476230-5-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Co-developed-by: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Daniel Micay <danielmicay@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

slab: clean up function declarations

In order to have more readable and regular declarations, move __must_check
to the line above the main function declaration and add all the missing
parameter names.

Link: https://lkml.kernel.org/r/20210818214021.2476230-4-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Suggested-by: Joe Perches <joe@perches.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Daniel Micay <danielmicay@gmail.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

checkpatch: add __alloc_size() to known $Attribute

Make sure checkpatch.pl doesn't get confused about finding the
__alloc_size attribute on functions.

Link: https://lkml.kernel.org/r/20210818214021.2476230-3-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Suggested-by: Joe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Daniel Micay <danielmicay@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

Compiler Attributes: Add __alloc_size for better bounds checking fix

Adjust the warning logic to deal with pre-9.1 gcc behaviors.

Link: https://lkml.kernel.org/r/20210827151327.2729736-1-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

Compiler Attributes: add __alloc_size() for better bounds checking

Patch series "Add __alloc_size() for better bounds checking", v2.

GCC and Clang both use the "alloc_size" attribute to assist with bounds
checking around the use of allocation functions.  Add the attribute,
adjust the Makefile to silence needless warnings, and add the hints to the
allocators where possible.  These changes have been in use for a while now
in GrapheneOS.

This patch (of 2):

GCC and Clang can use the "alloc_size" attribute to better inform the
results of __builtin_object_size() (for compile-time constant values).
Clang can additionally use alloc_size to inform the results of
__builtin_dynamic_object_size() (for run-time values).

Because GCC sees the frequent use of struct_size() as an allocator size
argument, and notices it can return SIZE_MAX (the overflow indication), it
complains about these call sites may overflow (since SIZE_MAX is greater
than the default -Walloc-size-larger-than=PTRDIFF_MAX).  This isn't
helpful since we already know a SIZE_MAX will be caught at run-time (this
was an intentional design).  Instead, just disable this check as it is
both a false positive and redundant.  (Clang does not have this warning
option.)

Link: https://lkml.kernel.org/r/20210818214021.2476230-1-keescook@chromium.org
Link: https://lkml.kernel.org/r/20210818214021.2476230-2-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Daniel Micay <danielmicay@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

mm: unexport {,un}lock_page_memcg

These are only used in built-in core mm code.

Link: https://lkml.kernel.org/r/20210820095815.445392-3-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

mm: unexport folio_memcg_{,un}lock

Patch series "unexport memcg locking helpers".

Neither the old page-based nor the new folio-based memcg locking helpers
are used in modular code at all, so drop the exports.

This patch (of 2):

folio_memcg_{,un}lock are only used in built-in core mm code.

Link: https://lkml.kernel.org/r/20210820095815.445392-1-hch@lst.de
Link: https://lkml.kernel.org/r/20210820095815.445392-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

mm: migrate: change to use bool type for 'page_was_mapped'

Change to use bool type for 'page_was_mapped' variable making it more
readable.

Link: https://lkml.kernel.org/r/ce1279df18d2c163998c403e0b5ec6d3f6f90f7a.1629447552.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

mm: migrate: fix the incorrect function name in comments

since commit a98a2f0c8ce1 ("mm/rmap: split migration into its own
function"), the migration ptes establishment has been split into a
separate try_to_migrate() function, thus update the related comments.

Link: https://lkml.kernel.org/r/5b824bad6183259c916ae6cf42f81d14c6118b06.1629447552.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

mm: migrate: introduce a local variable to get the number of pages

Use thp_nr_pages() instead of compound_nr() to get the number of pages for
THP page, meanwhile introducing a local variable 'nr_pages' to avoid
getting the number of pages repeatedly.

Link: https://lkml.kernel.org/r/a8e331ac04392ee230c79186330fb05e86a2aa77.1629447552.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

mm: migrate: simplify the file-backed pages validation when migrating its mapping

Patch series "Some cleanup for page migration", v3.

This patchset does some cleanups and improvements for page migration.

This patch (of 4):

There is no need to validate the file-backed page's refcount before trying
to freeze the page's expected refcount, instead we can rely on the
folio_ref_freeze() to validate if the page has the expected refcount
before migrating its mapping.

Moreover we are always under the page lock when migrating the page
mapping, which means nowhere else can remove it from the page cache, so we
can remove the xas_load() validation under the i_pages lock.

Link: https://lkml.kernel.org/r/cover.1629447552.git.baolin.wang@linux.alibaba.com
Link: https://lkml.kernel.org/r/df4c129fd8e86a95dbc55f4663d77441cc0d3bd1.1629447552.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Alistair Popple <apopple@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

mm: move kvmalloc-related functions to slab.h

Not all files in the kernel should include mm.h.  Migrating callers from
kmalloc to kvmalloc is easier if the kvmalloc functions are in slab.h.

[akpm@linux-foundation.org: move the new kvrealloc() also]
Link: https://lkml.kernel.org/r/20210622215757.3525604-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Pekka Enberg <penberg@kernel.org>
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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

mm/workingset: correct kernel-doc notations

Use the documented kernel-doc format to prevent kernel-doc warnings.

mm/workingset.c:256: warning: No description found for return value of 'workingset_eviction'
mm/workingset.c:285: warning: Function parameter or member 'folio' not described in 'workingset_refault'
mm/workingset.c:285: warning: Excess function parameter 'page' description in 'workingset_refault'

Link: https://lkml.kernel.org/r/20210808203153.10678-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

Merge branch 'akpm-current/current'

Merge remote-tracking branch 'folio/for-next'

# Conflicts:
# mm/filemap.c
# mm/rmap.c
# mm/util.c

Merge remote-tracking branch 'cxl/next'

Merge remote-tracking branch 'rust/rust-next'

Merge remote-tracking branch 'memblock/for-next'

Merge remote-tracking branch 'kunit-next/kunit'

Merge remote-tracking branch 'kgdb/kgdb/for-next'

Merge remote-tracking branch 'auxdisplay/auxdisplay'

Merge remote-tracking branch 'hyperv/hyperv-next'

Merge remote-tracking branch 'nvmem/for-next'

Merge remote-tracking branch 'slimbus/for-next'

Merge remote-tracking branch 'gnss/gnss-next'

Merge remote-tracking branch 'kspp/for-next/kspp'

# Conflicts:
# Makefile

Merge remote-tracking branch 'ntb/ntb-next'

Merge remote-tracking branch 'at24/at24/for-next'

Merge remote-tracking branch 'nvdimm/libnvdimm-for-next'

Merge remote-tracking branch 'rtc/rtc-next'

Merge remote-tracking branch 'coresight/next'

Merge remote-tracking branch 'livepatching/for-next'

Merge remote-tracking branch 'kselftest/next'

Merge remote-tracking branch 'userns/for-next'

Merge remote-tracking branch 'pwm/for-next'

Merge remote-tracking branch 'pinctrl/for-next'

Merge remote-tracking branch 'gpio-brgl/gpio/for-next'

Merge remote-tracking branch 'rpmsg/for-next'

Merge remote-tracking branch 'vhost/linux-next'

# Conflicts:
# drivers/virtio/virtio.c
# include/uapi/linux/virtio_ids.h

Merge remote-tracking branch 'scsi/for-next'

# Conflicts:
# drivers/scsi/st.c

Merge remote-tracking branch 'cgroup/for-next'

Merge remote-tracking branch 'dmaengine/next'

Merge remote-tracking branch 'vfio/next'

Merge remote-tracking branch 'extcon/extcon-next'

Merge remote-tracking branch 'usb/usb-next'

Merge remote-tracking branch 'ipmi/for-next'

Merge remote-tracking branch 'chrome-platform/for-next'

Merge remote-tracking branch 'drivers-x86/for-next'

Merge remote-tracking branch 'percpu/for-next'

Merge remote-tracking branch 'xen-tip/linux-next'

Merge remote-tracking branch 'kvms390/next'

Merge remote-tracking branch 'kvm-arm/next'

Merge remote-tracking branch 'kvm/next'

Merge remote-tracking branch 'rcu/rcu/next'

# Conflicts:
# kernel/time/tick-internal.h

Merge remote-tracking branch 'ftrace/for-next'

# Conflicts:
# MAINTAINERS

Merge remote-tracking branch 'tip/auto-latest'

Merge remote-tracking branch 'mailbox/mailbox-for-next'

Merge remote-tracking branch 'devicetree/for-next'

Merge remote-tracking branch 'iommu/next'

Merge remote-tracking branch 'watchdog/master'

Merge remote-tracking branch 'keys/keys-next'

# Conflicts:
# certs/system_keyring.c

Merge remote-tracking branch 'integrity/next-integrity'

Merge remote-tracking branch 'apparmor/apparmor-next'

Merge remote-tracking branch 'security/next-testing'

Merge remote-tracking branch 'backlight/for-backlight-next'

Merge remote-tracking branch 'mfd/for-mfd-next'

Merge remote-tracking branch 'block/for-next'

Merge remote-tracking branch 'input/next'

Merge remote-tracking branch 'modules/modules-next'

Merge remote-tracking branch 'imx-drm/imx-drm/next'

Merge remote-tracking branch 'amdgpu/drm-next'

# Conflicts:
# drivers/gpu/drm/amd/amdgpu/amdgpu_ras_eeprom.c

Merge remote-tracking branch 'drm-misc/for-linux-next'

Merge remote-tracking branch 'nand/nand/next'

Merge remote-tracking branch 'mtd/mtd/next'

Merge remote-tracking branch 'bluetooth/master'

Merge remote-tracking branch 'rdma/for-next'

Merge remote-tracking branch 'swiotlb/linux-next'

# Conflicts:
# kernel/dma/direct.c

Merge remote-tracking branch 'dlm/next'

Merge remote-tracking branch 'ieee1394/for-next'

Merge remote-tracking branch 'thermal/thermal/linux-next'

Merge remote-tracking branch 'cpupower/cpupower'

Merge remote-tracking branch 'pm/linux-next'

Merge remote-tracking branch 'v4l-dvb-next/master'

Merge remote-tracking branch 'jc_docs/docs-next'

Merge remote-tracking branch 'i2c/i2c/for-next'

Merge remote-tracking branch 'hid/for-next'

Merge remote-tracking branch 'pstore/for-next/pstore'

Merge remote-tracking branch 'pci/next'

# Conflicts:
# MAINTAINERS
# drivers/net/ethernet/broadcom/bnx2.c
# drivers/net/ethernet/broadcom/bnxt/bnxt.c

Merge remote-tracking branch 'printk/for-next'

# Conflicts:
# MAINTAINERS

Merge remote-tracking branch 'vfs/for-next'

Merge remote-tracking branch 'zonefs/for-next'

Merge remote-tracking branch 'xfs/for-next'