kernel-docs that are in include/linux/highmem.h and in
include/linux/highmem-internal.h should be included in highmem.rst.

Use kdocs directives to include the above-mentioned comments into
highmem.rst.

Link: https://lkml.kernel.org/r/20220428212455.892-3-fmdefrancesco@gmail.comSigned-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Suggested-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Patch series "Extend and reorganize Highmem's documentation", v4.

This series has the purpose to extend and reorganize Highmem's
documentation.

This is a work in progress because some information should still be moved
from highmem.rst to highmem.h and highmem-internal.h.  Specifically I'm
talking about moving the "how to" information to the relevant headers, as
it as been suggested by Ira Weiny (Intel).

Also, this is a work in progress because some kdocs in highmem.h and
highmem-internal.h should be improved.


This patch (of 4):

`scripts/kernel-doc -v -none include/linux/highmem*` reports the following
warnings:

include/linux/highmem.h:160: warning: expecting prototype for kunmap_atomic(). Prototype was for nr_free_highpages() instead
include/linux/highmem.h:204: warning: No description found for return value of 'alloc_zeroed_user_highpage_movable'
include/linux/highmem-internal.h:256: warning: Function parameter or member '__addr' not described in 'kunmap_atomic'
include/linux/highmem-internal.h:256: warning: Excess function parameter 'addr' description in 'kunmap_atomic'

Fix these warnings by (1) moving the kernel-doc comments from highmem.h to
highmem-internal.h (which is the file were the kunmap_atomic() macro is
actually defined), (2) extending and merging it with the comment which was
already in highmem-internal.h, and (3) using correct parameter names (4)
correcting a few technical inaccuracies in comments, and (5) adding a
deprecation notice in kunmap_atomic() for consistency with kmap_atomic().

Link: https://lkml.kernel.org/r/20220428212455.892-1-fmdefrancesco@gmail.com
Link: https://lkml.kernel.org/r/20220428212455.892-2-fmdefrancesco@gmail.comSigned-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Originally, do num_poisoned_pages_inc() in memory failure routine, use
num_poisoned_pages_dec() to rollback the number if filtered/ cancelled.

Suggested by Naoya, do num_poisoned_pages_inc() only in action_result(),
this make this clear and simple.

Link: https://lkml.kernel.org/r/20220509105641.491313-6-pizhenwei@bytedance.comSigned-off-by: zhenwei pi <pizhenwei@bytedance.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

hwpoison filter is enabled by hwpoison-inject module, after removing this
module, hwpoison filter still works.  What is worse, user can not find the
debugfs entries to know this.

Disable the hwpoison filter during removing hwpoison-inject module.

Link: https://lkml.kernel.org/r/20220509105641.491313-5-pizhenwei@bytedance.comSigned-off-by: zhenwei pi <pizhenwei@bytedance.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

hwpoison_filter is missing in the soft offline path, this leads an issue:
after enabling the corrupt filter, the user process still has a chance to
inject hwpoison fault by madvise(addr, len, MADV_SOFT_OFFLINE) at PFN
which is expected to reject.

Also do a minor change in comment of memory_failure().

Link: https://lkml.kernel.org/r/20220509105641.491313-4-pizhenwei@bytedance.comSigned-off-by: zhenwei pi <pizhenwei@bytedance.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Don't decrease the number of poisoned pages in page_alloc.c, let the
memory-failure.c do inc/dec poisoned pages only.

Also simplify unpoison_memory(), only decrease the number of
poisoned pages when:
 - TestClearPageHWPoison() succeed
 - put_page_back_buddy succeed

After decreasing, print necessary log.

Finally, remove clear_page_hwpoison() and unpoison_taken_off_page().

Link: https://lkml.kernel.org/r/20220509105641.491313-3-pizhenwei@bytedance.comSigned-off-by: zhenwei pi <pizhenwei@bytedance.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Patch series "memory-failure: fix hwpoison_filter", v2.

As well known, the memory failure mechanism handles memory corrupted
event, and try to send SIGBUS to the user process which uses this
corrupted page.

For the virtualization case, QEMU catches SIGBUS and tries to inject MCE
into the guest, and the guest handles memory failure again.  Thus the
guest gets the minimal effect from hardware memory corruption.

The further step I'm working on:

1, try to modify code to decrease poisoned pages in a single place
   (mm/memofy-failure.c: simplify num_poisoned_pages_dec in this series).

2, try to use page_handle_poison() to handle SetPageHWPoison() and
   num_poisoned_pages_inc() together.  It would be best to call
   num_poisoned_pages_inc() in a single place too.

3, introduce memory failure notifier list in memory-failure.c: notify
   the corrupted PFN to someone who registers this list.  If I can
   complete [1] and [2] part, [3] will be quite easy(just call notifier
   list after increasing poisoned page).

4, introduce memory recover VQ for memory balloon device, and registers
   memory failure notifier list.  During the guest kernel handles memory
   failure, balloon device gets notified by memory failure notifier list,
   and tells the host to recover the corrupted PFN(GPA) by the new VQ.

5, host side remaps the corrupted page(HVA), and tells the guest side
   to unpoison the PFN(GPA).  Then the guest fixes the corrupted page(GPA)
   dynamically.


This patch (of 5):

clear_hwpoisoned_pages() clears HWPoison flag and decreases the number of
poisoned pages, this actually works as part of memory failure.

Move this function from sparse.c to memory-failure.c, finally there is no
CONFIG_MEMORY_FAILURE in sparse.c.

Link: https://lkml.kernel.org/r/20220509105641.491313-1-pizhenwei@bytedance.com
Link: https://lkml.kernel.org/r/20220509105641.491313-2-pizhenwei@bytedance.comSigned-off-by: zhenwei pi <pizhenwei@bytedance.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

current->comm[] is not a string (no guarantee for a zero byte in it).

strlcpy(s1, s2, l) is calling strlen(s2), potentially
causing out-of-bound access, as reported by syzbot:

detected buffer overflow in __fortify_strlen
------------[ cut here ]------------
kernel BUG at lib/string_helpers.c:980!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 4087 Comm: dhcpcd-run-hooks Not tainted 5.18.0-rc3-syzkaller-01537-g20b87e7c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:fortify_panic+0x18/0x1a lib/string_helpers.c:980
Code: 8c e8 c5 ba e1 fa e9 23 0f bf fa e8 0b 5d 8c f8 eb db 55 48 89 fd e8 e0 49 40 f8 48 89 ee 48 c7 c7 80 f5 26 8a e8 99 09 f1 ff <0f> 0b e8 ca 49 40 f8 48 8b 54 24 18 4c 89 f1 48 c7 c7 00 00 27 8a
RSP: 0018:ffffc900000074a8 EFLAGS: 00010286

RAX: 000000000000002c RBX: ffff88801226b728 RCX: 0000000000000000
RDX: ffff8880198e0000 RSI: ffffffff81600458 RDI: fffff52000000e87
RBP: ffffffff89da2aa0 R08: 000000000000002c R09: 0000000000000000
R10: ffffffff815fae2e R11: 0000000000000000 R12: ffff88801226b700
R13: ffff8880198e0830 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5876ad6ff8 CR3: 000000001a48c000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 __fortify_strlen include/linux/fortify-string.h:128 [inline]
 strlcpy include/linux/fortify-string.h:143 [inline]
 __set_page_owner_handle+0x2b1/0x3e0 mm/page_owner.c:171
 __set_page_owner+0x3e/0x50 mm/page_owner.c:190
 prep_new_page mm/page_alloc.c:2441 [inline]
 get_page_from_freelist+0xba2/0x3e00 mm/page_alloc.c:4182
 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5408
 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2272
 alloc_slab_page mm/slub.c:1799 [inline]
 allocate_slab+0x26c/0x3c0 mm/slub.c:1944
 new_slab mm/slub.c:2004 [inline]
 ___slab_alloc+0x8df/0xf20 mm/slub.c:3005
 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3092
 slab_alloc_node mm/slub.c:3183 [inline]
 slab_alloc mm/slub.c:3225 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3232 [inline]
 kmem_cache_alloc+0x360/0x3b0 mm/slub.c:3242
 dst_alloc+0x146/0x1f0 net/core/dst.c:92

Link: https://lkml.kernel.org/r/20220509145949.265184-1-eric.dumazet@gmail.com
Fixes: 865ed6a3 ("mm/page_owner: record task command name")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Waiman Long <longman@redhat.com>
Acked-by: Shakeel Butt <shakeelb@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Various readability clean-ups of KASAN Kconfig options.

No functional changes.

Link: https://lkml.kernel.org/r/c160840dd9e4b1ad5529ecfdb0bba35d9a14d826.1652203271.git.andreyknvl@google.com
Link: https://lkml.kernel.org/r/47afaecec29221347bee49f58c258ac1ced3b429.1652123204.git.andreyknvl@google.comSigned-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Move the "Boot parameters" section in KASAN documentation next to the
section that describes KASAN build options.

No content changes.

Link: https://lkml.kernel.org/r/870628e1293b4f44edf7cbcb92374ff9eb7503d7.1652203271.git.andreyknvl@google.com
Link: https://lkml.kernel.org/r/ec9c923f35e7c5312836c4624a7f317dc1ee2c1c.1652123204.git.andreyknvl@google.comSigned-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Do assorted clean-ups and improvements to KASAN documentation, including:

- Describe each mode in a dedicated paragraph.
- Split out a Support section that describes in details which compilers,
  architectures and memory types each mode requires/supports.
- Capitalize the first letter in the names of each KASAN mode.

[andreyknvl@google.com: rewording, per Marco]
  Link: https://lkml.kernel.org/r/896b2d914d6b50d677fd7b38f76967cc705c01ba.1652203271.git.andreyknvl@google.com
Link: https://lkml.kernel.org/r/5bd58ebebf066593ce0e1d265d60278b5f5a1874.1652123204.git.andreyknvl@google.comSigned-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Rename KASAN_KMALLOC_* shadow values to KASAN_SLAB_*, as they are used for
all slab allocations, not only for kmalloc.

Also rename KASAN_FREE_PAGE to KASAN_PAGE_FREE to be consistent with
KASAN_PAGE_REDZONE and KASAN_SLAB_FREE.

Link: https://lkml.kernel.org/r/bebcaf4eafdb0cabae0401a69c0af956aa87fcaa.1652111464.git.andreyknvl@google.comSigned-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Consistently use tabs instead of spaces to shadow value definitions.

Link: https://lkml.kernel.org/r/00e7e66b5fc375d58200dc1489949b3edcd096b7.1652111464.git.andreyknvl@google.comSigned-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Clean up comments in mm/kasan/kasan.h: clarify, unify styles, fix
punctuation, etc.

Link: https://lkml.kernel.org/r/a0680ff30035b56cb7bdd5f59fd400e71712ceb5.1652111464.git.andreyknvl@google.comSigned-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

The per-CPU resource vmap_block_queue is accessed via get_cpu_var().  That
macro disables preemption and then loads the pointer from the current CPU.

This doesn't work on PREEMPT_RT because a spinlock_t is later accessed
within the preempt-disable section.

There is no need to disable preemption while accessing the per-CPU struct
vmap_block_queue because the list is protected with a spinlock_t.  The
per-CPU struct is also accessed cross-CPU in purge_fragmented_blocks().

It is possible that by using raw_cpu_ptr() the code migrates to another
CPU and uses struct from another CPU.  This is fine because the list is
locked and the locked section is very short.

Use raw_cpu_ptr() to access vmap_block_queue.

Link: https://lkml.kernel.org/r/YnKx3duAB53P7ojN@linutronix.deSigned-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Fixes the following sparse warnings:

include/trace/events/*: sparse: cast to restricted gfp_t
include/trace/events/*: sparse: restricted gfp_t degrades to integer

gfp_t type is bitwise and requires __force attributes for any casts.

Link: https://lkml.kernel.org/r/331d88fe-f4f7-657c-02a2-d977f15fbff6@openvz.orgSigned-off-by: Vasily Averin <vvs@openvz.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

The 2nd trial allocation under per-cpu presumption has been used to
prevent regression of allocation failure.  However, it makes trouble for
maintenance without significant benefit.  The slowpath branch is executed
extremely rarely: getting there is problematic.  Therefore, we delete this
branch.

Since b09ab054 ("zram: support BDI_CAP_STABLE_WRITES"), zram has used
QUEUE_FLAG_STABLE_WRITES to prevent buffer change between 1st and 2nd
memory allocations.  Since we remove second trial memory allocation logic,
we could remove the STABLE_WRITES flag because there is no change buffer
to be modified under us.

Link: https://lkml.kernel.org/r/20220505094443.11728-1-avromanov@sberdevices.ruSigned-off-by: Alexey Romanov <avromanov@sberdevices.ru>
Signed-off-by: Dmitry Rokosov <ddrokosov@sberdevices.ru>
Acked-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Add call_site, bytes_alloc and gfp_flags fields to the output of the
percpu_alloc_percpu ftrace event:

mkdir-4393  [001]   169.334788: percpu_alloc_percpu:
 call_site=mem_cgroup_css_alloc+0xa6 reserved=0 is_atomic=0 size=2408 align=8
  base_addr=0xffffc7117fc00000 off=402176 ptr=0x3dc867a62300 bytes_alloc=14448
   gfp_flags=GFP_KERNEL_ACCOUNT

This is required to track memcg-accounted percpu allocations.

Link: https://lkml.kernel.org/r/a07be858-c8a3-7851-9086-e3262cbcf707@openvz.orgSigned-off-by: Vasily Averin <vvs@openvz.org>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

A semantic conflict between commit 5603f9bd ("docs: vm/page_owner: use
literal blocks for param description") and a change queued for v5.19
authored by Jiajian Ye ("tools/vm/page_owner_sort.c: support sorting
blocks by multiple keys") results in a warning from "make htmldocs"
saying:

  [...]/vm/page_owner.rst:176: WARNING: Literal block expected; none found.

This is because a literal block in ReST ends at a line which has the same
indent as the paragraph preceding it.  In this case the one with no
indent.

Indent the two "For --xxxx option:" lines by two columns and make the
whole section a literal block.

While at it, fix indents by white spaces of "ator" keys.

Link: https://lkml.kernel.org/r/fdfecc82-d41e-6d8a-738d-4beb6faa27fb@gmail.comSigned-of-by: Akira Yokosawa <akiyks@gmail.com>
Reported-by: Shenghong Han <hanshenghong2019@email.szu.edu.cn>
Cc: Jiajian Ye <yejiajian2018@email.szu.edu.cn>
Cc: Chongxi Zhao <zhaochongxi2019@email.szu.edu.cn>
Cc: Yinan Zhang <zhangyinan2019@email.szu.edu.cn>
Cc: Yixuan Cao <caoyixuan2019@email.szu.edu.cn>
Cc: Yongqiang Liu <liuyongqiang13@huawei.com>
Cc: Yuhong Feng <yuhongf@szu.edu.cn>
Cc: Haowen Bai <baihaowen@meizu.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Fix the following coccicheck warnings:

./mm/damon/reclaim.c:241:30-33: WARNING: Suspicious code. resource_size is maybe missing with res.

Link: https://lkml.kernel.org/r/20220507032512.129598-1-jiapeng.chong@linux.alibaba.comSigned-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: "Boehme, Markus" <markubo@amazon.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

p4d_clear_huge may be optimized for void return type and function usage. 
vunmap_p4d_range function saves a few steps here.

Link: https://lkml.kernel.org/r/20220507150630.90399-1-kunyu@nfschina.comSigned-off-by: Li kunyu <kunyu@nfschina.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

As commit d283d422 ("x86: mm: add x86_64 support for page table
check"), enable ARCH_SUPPORTS_PAGE_TABLE_CHECK on riscv.

Add additional page table check stubs for page table helpers, these stubs
can be used to check the existing page table entries.

Link: https://lkml.kernel.org/r/20220507110114.4128854-7-tongtiangen@huawei.comSigned-off-by: Tong Tiangen <tongtiangen@huawei.com>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

As commit d283d422 ("x86: mm: add x86_64 support for page table
check") , enable ARCH_SUPPORTS_PAGE_TABLE_CHECK on arm64.

Add additional page table check stubs for page table helpers, these stubs
can be used to check the existing page table entries.

Link: https://lkml.kernel.org/r/20220507110114.4128854-6-tongtiangen@huawei.comSigned-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Currently, there is no architecture definition __HAVE_ARCH_PTEP_CLEAR,
Generic ptep_clear() is the only definition for all architecture, So drop
the "#ifndef __HAVE_ARCH_PTEP_CLEAR".

Link: https://lkml.kernel.org/r/20220507110114.4128854-5-tongtiangen@huawei.comSigned-off-by: Tong Tiangen <tongtiangen@huawei.com>
Suggested-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Move ptep_clear() to the include/linux/pgtable.h and add page table check
relate hooks to some helpers, it's prepare for support page table check
feature on new architecture.

Optimize the implementation of ptep_clear(), page table hooks added page
table check stubs, the interface control should be at stubs, there is no
rationale for doing a IS_ENABLED() check here.

For architectures that do not enable CONFIG_PAGE_TABLE_CHECK, they will
call a fallback page table check stubs[1] when getting their page table
helpers[2] in include/linux/pgtable.h.

[1] page table check stubs defined in include/linux/page_table_check.h
[2] ptep_clear() ptep_get_and_clear()  pmdp_huge_get_and_clear()
pudp_huge_get_and_clear()

Link: https://lkml.kernel.org/r/20220507110114.4128854-4-tongtiangen@huawei.comSigned-off-by: Tong Tiangen <tongtiangen@huawei.com>
Acked-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

The pxx_user_accessible_page() checks the PTE bit, it's
architecture-specific code, move them into x86's pgtable.h.

These helpers are being moved out to make the page table check framework
platform independent.

Link: https://lkml.kernel.org/r/20220507110114.4128854-3-tongtiangen@huawei.comSigned-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Acked-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Patch series "mm: page_table_check: add support on arm64 and riscv", v7.

Page table check performs extra verifications at the time when new pages
become accessible from the userspace by getting their page table entries
(PTEs PMDs etc.) added into the table.  It is supported on X86[1].

This patchset made some simple changes and make it easier to support new
architecture, then we support this feature on ARM64 and RISCV.

[1]https://lore.kernel.org/lkml/20211123214814.3756047-1-pasha.tatashin@soleen.com/


This patch (of 6):

Compared with PxD_PAGE_SIZE, which is defined and used only on X86,
PxD_SIZE is more common in each architecture.  Therefore, it is more
reasonable to use PxD_SIZE instead of PxD_PAGE_SIZE in page_table_check.c.
At the same time, it is easier to support page table check in other
architectures.  The substitution has no functional impact on the x86.

Link: https://lkml.kernel.org/r/20220507110114.4128854-1-tongtiangen@huawei.com
Link: https://lkml.kernel.org/r/20220507110114.4128854-2-tongtiangen@huawei.comSigned-off-by: Tong Tiangen <tongtiangen@huawei.com>
Suggested-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Pass in the folios that we already have in each caller.  Saves a
lot of calls to compound_head().

Link: https://lkml.kernel.org/r/20220504182857.4013401-27-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

This is the folio equivalent of PageMovable() which is needed to
convert mm/migrate.c to folios.

Link: https://lkml.kernel.org/r/20220504182857.4013401-26-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

This is the equivalent of PageMappingFlags and is needed for converting
mm/migrate.c to folios.

Link: https://lkml.kernel.org/r/20220504182857.4013401-25-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

shmem_swapin_page() only brings in order-0 pages, which are folios
by definition.

Link: https://lkml.kernel.org/r/20220504182857.4013401-24-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Rename shmem_alloc_and_acct_page() to shmem_alloc_and_acct_folio() and
have it return a folio, then use a folio throuughout shmem_getpage_gfp(). 
It continues to return a struct page.

Link: https://lkml.kernel.org/r/20220504182857.4013401-23-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Convert shmem_alloc_hugepage() to return the folio that it uses and use a
folio throughout shmem_alloc_and_acct_page().  Continue to return a page
from shmem_alloc_and_acct_page() for now.

Link: https://lkml.kernel.org/r/20220504182857.4013401-22-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Call vma_alloc_folio() directly instead of alloc_page_vma().  Add a
shmem_alloc_page() wrapper to avoid changing the callers.

Link: https://lkml.kernel.org/r/20220504182857.4013401-21-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

This is a straightforward conversion.

Link: https://lkml.kernel.org/r/20220504182857.4013401-20-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Shrinks shmem_add_to_page_cache() by 16 bytes.  All the callers grow,
but this is temporary as they will all be converted to folios soon.

Link: https://lkml.kernel.org/r/20220504182857.4013401-19-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

The only use of the page argument to cgroup_throttle_swaprate() is to get
the node ID, and this will be the same for all pages in the folio, so just
pass in the first page of the folio.

Link: https://lkml.kernel.org/r/20220504182857.4013401-18-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

When calling split_huge_page() we usually have to find the precise page,
but that's not necessary here because we only need to unlock and put the
folio afterwards.  Saves 231 bytes of text (20% of this function).

Link: https://lkml.kernel.org/r/20220504182857.4013401-17-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

These are all straightforward conversions to the folio API.

Link: https://lkml.kernel.org/r/20220504182857.4013401-16-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

The call to can_split_folio() in vmscan is currently guarded by a test of
PageTransHuge() so the BUILD_BUG() is eliminated if THP are disabled.  The
next patch replaces that test with folio_test_large() which may be true,
even when THP are disabled.  However, if THP are disabled, we cannot
split, so an unconditional return of false is appropriate.

Link: https://lkml.kernel.org/r/20220504182857.4013401-15-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>