Document alloc_pages() for both NUMA and non-NUMA cases as kernel-doc
doesn't care.

Link: https://lkml.kernel.org/r/20210225150642.2582252-6-willy@infradead.orgSigned-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: NMike Rapoport <rppt@linux.ibm.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When CONFIG_NUMA is enabled, alloc_pages() is a wrapper around
alloc_pages_current().  This is pointless, just implement alloc_pages()
directly.

Link: https://lkml.kernel.org/r/20210225150642.2582252-5-willy@infradead.orgSigned-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There are only two callers of __alloc_pages() so prune the thicket of
alloc_page variants by combining the two functions together.  Current
callers of __alloc_pages() simply add an extra 'NULL' parameter and
current callers of __alloc_pages_nodemask() call __alloc_pages() instead.

Link: https://lkml.kernel.org/r/20210225150642.2582252-4-willy@infradead.orgSigned-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Shorten some overly-long lines by renaming this identifier.

Link: https://lkml.kernel.org/r/20210225150642.2582252-3-willy@infradead.orgSigned-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "Rationalise __alloc_pages wrappers", v3.

I was poking around the __alloc_pages variants trying to understand why
they each exist, and couldn't really find a good justification for keeping
__alloc_pages and __alloc_pages_nodemask as separate functions.  That led
to getting rid of alloc_pages_current() and then I noticed the
documentation was bad, and then I noticed the mempolicy documentation
wasn't included.

Anyway, this is all cleanups & doc fixes.

This patch (of 7):

We have two masks involved -- the nodemask and the gfp mask, so alloc_mask
is an unclear name.

Link: https://lkml.kernel.org/r/20210225150642.2582252-2-willy@infradead.orgSigned-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Tidy things up and delete comments stating the obvious with typos or
making no sense.

Link: https://lkml.kernel.org/r/20210303071609.797782-2-yuzhao@google.comSigned-off-by: NYu Zhao <yuzhao@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The naming convention used in include/linux/page-flags-layout.h:
  *_SHIFT: the number of bits trying to allocate
  *_WIDTH: the number of bits successfully allocated

So when it comes to LAST_CPUPID_WIDTH, we need to check whether all
previous *_WIDTH and LAST_CPUPID_SHIFT can fit into page flags. This
means we need to use NODES_WIDTH, not NODES_SHIFT.

Link: https://lkml.kernel.org/r/20210303071609.797782-1-yuzhao@google.comSigned-off-by: NYu Zhao <yuzhao@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

__alloc_contig_migrate_range already has lru_add_drain_all call via
migrate_prep.  It's necessary to move LRU taget pages into LRU list to be
able to isolated.  However, lru_add_drain_all call after
__alloc_contig_migrate_range is pointless since it has changed source page
freeing from putback_lru_pages to put_page[1].

This patch removes it.

[1] c6c919eb, ("mm: use put_page() to free page instead of putback_lru_page()"

Link: https://lkml.kernel.org/r/20210303204512.2863087-1-minchan@kernel.orgSigned-off-by: NMinchan Kim <minchan@kernel.org>
Reviewed-by: NOscar Salvador <osalvador@suse.de>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The information that some PFNs are busy is:

a) not helpful for ordinary users: we don't even know *who* called
   alloc_contig_range(). This is certainly not worth a pr_info.*().

b) not really helpful for debugging: we don't have any details *why*
   these PFNs are busy, and that is what we usually care about.

c) not complete: there are other cases where we fail alloc_contig_range()
   using different paths that are not getting recorded.

For example, we reach this path once we succeeded in isolating pageblocks,
but failed to migrate some pages - which can happen easily on ZONE_NORMAL
(i.e., has_unmovable_pages() is racy) but also on ZONE_MOVABLE i.e., we
would have to retry longer to migrate).

For example via virtio-mem when unplugging memory, we can create quite
some noise (especially with ZONE_NORMAL) that is not of interest to users
- it's expected that some allocations may fail as memory is busy.

Let's just drop that pr_info_ratelimit() and rather implement a dynamic
debugging mechanism in the future that can give us a better reason why
alloc_contig_range() failed on specific pages.

Link: https://lkml.kernel.org/r/20210301150945.77012-1-david@redhat.comSigned-off-by: NDavid Hildenbrand <david@redhat.com>
Reviewed-by: NZi Yan <ziy@nvidia.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: NOscar Salvador <osalvador@suse.de>
Acked-by: NMinchan Kim <minchan@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mem_init_print_info() is called in mem_init() on each architecture, and
pass NULL argument, so using void argument and move it into mm_init().

Link: https://lkml.kernel.org/r/20210317015210.33641-1-wangkefeng.wang@huawei.comSigned-off-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>	[x86]
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>	[powerpc]
Acked-by: NDavid Hildenbrand <david@redhat.com>
Tested-by: Anatoly Pugachev <matorola@gmail.com>	[sparc64]
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>	[arm]
Acked-by: NMike Rapoport <rppt@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Guo Ren <guoren@kernel.org>
Cc: Yoshinori Sato <ysato@users.osdn.me>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Peter Zijlstra" <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add the irq_work_queue() call stack into the KASAN auxiliary stack in
order to improve KASAN reports.  this will let us know where the irq work
be queued.

Link: https://lkml.kernel.org/r/20210331063202.28770-1-qiang.zhang@windriver.comSigned-off-by: NZqiang <qiang.zhang@windriver.com>
Reviewed-by: NDmitry Vyukov <dvyukov@google.com>
Acked-by: NAndrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Walter Wu <walter-zh.wu@mediatek.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently, KASAN-KUnit tests can check that a particular annotated part of
code causes a KASAN report.  However, they do not check that no unwanted
reports happen between the annotated parts.

This patch implements these checks.

It is done by setting report_data.report_found to false in
kasan_test_init() and at the end of KUNIT_EXPECT_KASAN_FAIL() and then
checking that it remains false at the beginning of
KUNIT_EXPECT_KASAN_FAIL() and in kasan_test_exit().

kunit_add_named_resource() call is moved to kasan_test_init(), and the
value of fail_data.report_expected is kept as false in between
KUNIT_EXPECT_KASAN_FAIL() annotations for consistency.

Link: https://lkml.kernel.org/r/48079c52cc329fbc52f4386996598d58022fb872.1617207873.git.andreyknvl@google.comSigned-off-by: NAndrey Konovalov <andreyknvl@google.com>
Reviewed-by: NMarco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Why record task_work_add() call stack?  Syzbot reports many use-after-free
issues for task_work, see [1].  After seeing the free stack and the
current auxiliary stack, we think they are useless, we don't know where
the work was registered.  This work may be the free call stack, so we miss
the root cause and don't solve the use-after-free.

Add the task_work_add() call stack into the KASAN auxiliary stack in order
to improve KASAN reports.  It helps programmers solve use-after-free
issues.

[1]: https://groups.google.com/g/syzkaller-bugs/search?q=kasan%20use-after-free%20task_work_run

Link: https://lkml.kernel.org/r/20210316024410.19967-1-walter-zh.wu@mediatek.comSigned-off-by: NWalter Wu <walter-zh.wu@mediatek.com>
Suggested-by: NDmitry Vyukov <dvyukov@google.com>
Reviewed-by: NDmitry Vyukov <dvyukov@google.com>
Reviewed-by: NJens Axboe <axboe@kernel.dk>
Acked-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NAndrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Update the "Tests" section in KASAN documentation:

 - Add an introductory sentence.

 - Add proper indentation for the list of ways to run KUnit tests.

 - Punctuation, readability, and other minor clean-ups.

Link: https://lkml.kernel.org/r/fb08845e25c8847ffda271fa19cda2621c04a65b.1615559068.git.andreyknvl@google.comSigned-off-by: NAndrey Konovalov <andreyknvl@google.com>
Reviewed-by: NMarco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Update the "Ignoring accesses" section in KASAN documentation:

 - Mention __no_sanitize_address/noinstr.

 - Mention kasan_disable/enable_current().

 - Mention kasan_reset_tag()/page_kasan_tag_reset().

 - Readability and punctuation clean-ups.

Link: https://lkml.kernel.org/r/4531ba5f3eca61f6aade863c136778cc8c807a64.1615559068.git.andreyknvl@google.comSigned-off-by: NAndrey Konovalov <andreyknvl@google.com>
Reviewed-by: NMarco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Update the "Shadow memory" section in KASAN documentation:

 - Rearrange the introduction paragraph do it doesn't give a
   "KASAN has an issue" impression.

 - Update the list of architectures with vmalloc support.

 - Punctuation, readability, and other minor clean-ups.

Link: https://lkml.kernel.org/r/00f8c38b0fd5290a3f4dced04eaba41383e67e14.1615559068.git.andreyknvl@google.comSigned-off-by: NAndrey Konovalov <andreyknvl@google.com>
Reviewed-by: NMarco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Update the "Implementation details" section for HW_TAGS KASAN:

 - Punctuation, readability, and other minor clean-ups.

Link: https://lkml.kernel.org/r/ee2caf4c138cc1fd239822c2abefd5af6c057744.1615559068.git.andreyknvl@google.comSigned-off-by: NAndrey Konovalov <andreyknvl@google.com>
Reviewed-by: NMarco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Update the "Implementation details" section for SW_TAGS KASAN:

 - Clarify the introduction sentence.

 - Punctuation, readability, and other minor clean-ups.

Link: https://lkml.kernel.org/r/69b9b2e49d8cf789358fa24558be3fc0ce4ee32c.1615559068.git.andreyknvl@google.comSigned-off-by: NAndrey Konovalov <andreyknvl@google.com>
Reviewed-by: NMarco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Update the "Implementation details" section for generic KASAN:

 - Don't mention kmemcheck, it's not present in the kernel anymore.

 - Don't mention GCC as the only supported compiler.

 - Update kasan_mem_to_shadow() definition to match actual code.

 - Punctuation, readability, and other minor clean-ups.

Link: https://lkml.kernel.org/r/f2f35fdab701f8c709f63d328f98aec2982c8acc.1615559068.git.andreyknvl@google.comSigned-off-by: NAndrey Konovalov <andreyknvl@google.com>
Reviewed-by: NMarco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Update the "Boot parameters" section in KASAN documentation:

 - Mention panic_on_warn.

 - Mention kasan_multi_shot and its interaction with panic_on_warn.

 - Clarify kasan.fault=panic interaction with panic_on_warn.

 - A readability clean-up.

Link: https://lkml.kernel.org/r/01364952f15789948f0627d6733b5cdf5209f83a.1615559068.git.andreyknvl@google.comSigned-off-by: NAndrey Konovalov <andreyknvl@google.com>
Reviewed-by: NMarco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Update the "Error reports" section in KASAN documentation:

 - Mention that bug titles are best-effort.

 - Move and reword the part about auxiliary stacks from "Implementation
   details".

 - Punctuation, readability, and other minor clean-ups.

Link: https://lkml.kernel.org/r/3531e8fe6972cf39d1954e3643237b19eb21227e.1615559068.git.andreyknvl@google.comSigned-off-by: NAndrey Konovalov <andreyknvl@google.com>
Reviewed-by: NMarco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Update the "Usage" section in KASAN documentation:

 - Add inline code snippet markers.

 - Reword the part about stack traces for clarity.

 - Other minor clean-ups.

Link: https://lkml.kernel.org/r/48427809cd4b8b5d6bc00926cbe87e2b5081df17.1615559068.git.andreyknvl@google.comSigned-off-by: NAndrey Konovalov <andreyknvl@google.com>
Reviewed-by: NMarco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Update the "Overview" section in KASAN documentation:

 - Outline main use cases for each mode.

 - Mention that HW_TAGS mode need compiler support too.

 - Move the part about SLUB/SLAB support from "Usage" to "Overview".

 - Punctuation, readability, and other minor clean-ups.

Link: https://lkml.kernel.org/r/1486fba8514de3d7db2f47df2192db59228b0a7b.1615559068.git.andreyknvl@google.comSigned-off-by: NAndrey Konovalov <andreyknvl@google.com>
Reviewed-by: NMarco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Update KASAN documentation:

 - Give some sections clearer names.

 - Remove unneeded subsections in the "Tests" section.

 - Move the "For developers" section and split into subsections.

Link: https://lkml.kernel.org/r/c2bbb56eaea80ad484f0ee85bb71959a3a63f1d7.1615559068.git.andreyknvl@google.comSigned-off-by: NAndrey Konovalov <andreyknvl@google.com>
Reviewed-by: NMarco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This change uses the previously added memory initialization feature of
HW_TAGS KASAN routines for slab memory when init_on_free is enabled.

With this change, memory initialization memset() is no longer called when
both HW_TAGS KASAN and init_on_free are enabled.  Instead, memory is
initialized in KASAN runtime.

For SLUB, the memory initialization memset() is moved into
slab_free_hook() that currently directly follows the initialization loop.
A new argument is added to slab_free_hook() that indicates whether to
initialize the memory or not.

To avoid discrepancies with which memory gets initialized that can be
caused by future changes, both KASAN hook and initialization memset() are
put together and a warning comment is added.

Combining setting allocation tags with memory initialization improves
HW_TAGS KASAN performance when init_on_free is enabled.

Link: https://lkml.kernel.org/r/190fd15c1886654afdec0d19ebebd5ade665b601.1615296150.git.andreyknvl@google.comSigned-off-by: NAndrey Konovalov <andreyknvl@google.com>
Reviewed-by: NMarco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This change uses the previously added memory initialization feature of
HW_TAGS KASAN routines for slab memory when init_on_alloc is enabled.

With this change, memory initialization memset() is no longer called when
both HW_TAGS KASAN and init_on_alloc are enabled.  Instead, memory is
initialized in KASAN runtime.

The memory initialization memset() is moved into slab_post_alloc_hook()
that currently directly follows the initialization loop.  A new argument
is added to slab_post_alloc_hook() that indicates whether to initialize
the memory or not.

To avoid discrepancies with which memory gets initialized that can be
caused by future changes, both KASAN hook and initialization memset() are
put together and a warning comment is added.

Combining setting allocation tags with memory initialization improves
HW_TAGS KASAN performance when init_on_alloc is enabled.

Link: https://lkml.kernel.org/r/c1292aeb5d519da221ec74a0684a949b027d7720.1615296150.git.andreyknvl@google.comSigned-off-by: NAndrey Konovalov <andreyknvl@google.com>
Reviewed-by: NMarco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This change uses the previously added memory initialization feature of
HW_TAGS KASAN routines for page_alloc memory when init_on_alloc/free is
enabled.

With this change, kernel_init_free_pages() is no longer called when both
HW_TAGS KASAN and init_on_alloc/free are enabled.  Instead, memory is
initialized in KASAN runtime.

To avoid discrepancies with which memory gets initialized that can be
caused by future changes, both KASAN and kernel_init_free_pages() hooks
are put together and a warning comment is added.

This patch changes the order in which memory initialization and page
poisoning hooks are called.  This doesn't lead to any side-effects, as
whenever page poisoning is enabled, memory initialization gets disabled.

Combining setting allocation tags with memory initialization improves
HW_TAGS KASAN performance when init_on_alloc/free is enabled.

[andreyknvl@google.com: fix for "integrate page_alloc init with HW_TAGS"]
  Link: https://lkml.kernel.org/r/65b6028dea2e9a6e8e2cb779b5115c09457363fc.1617122211.git.andreyknvl@google.com

Link: https://lkml.kernel.org/r/e77f0d5b1b20658ef0b8288625c74c2b3690e725.1615296150.git.andreyknvl@google.comSigned-off-by: NAndrey Konovalov <andreyknvl@google.com>
Reviewed-by: NMarco Elver <elver@google.com>
Tested-by: NVlastimil Babka <vbabka@suse.cz>
Reviewed-by: NSergei Trofimovich <slyfox@gentoo.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This change adds an argument to kasan_poison() and kasan_unpoison() that
allows initializing memory along with setting the tags for HW_TAGS.

Combining setting allocation tags with memory initialization will improve
HW_TAGS KASAN performance when init_on_alloc/free is enabled.

This change doesn't integrate memory initialization with KASAN, this is
done is subsequent patches in this series.

Link: https://lkml.kernel.org/r/3054314039fa64510947e674180d675cab1b4c41.1615296150.git.andreyknvl@google.comSigned-off-by: NAndrey Konovalov <andreyknvl@google.com>
Reviewed-by: NMarco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "kasan: integrate with init_on_alloc/free", v3.

This patch series integrates HW_TAGS KASAN with init_on_alloc/free by
initializing memory via the same arm64 instruction that sets memory tags.

This is expected to improve HW_TAGS KASAN performance when
init_on_alloc/free is enabled.  The exact perfomance numbers are unknown
as MTE-enabled hardware doesn't exist yet.

This patch (of 5):

This change adds an argument to mte_set_mem_tag_range() that allows to
enable memory initialization when settinh the allocation tags.  The
implementation uses stzg instruction instead of stg when this argument
indicates to initialize memory.

Combining setting allocation tags with memory initialization will improve
HW_TAGS KASAN performance when init_on_alloc/free is enabled.

This change doesn't integrate memory initialization with KASAN, this is
done is subsequent patches in this series.

Link: https://lkml.kernel.org/r/cover.1615296150.git.andreyknvl@google.com
Link: https://lkml.kernel.org/r/d04ae90cc36be3fe246ea8025e5085495681c3d7.1615296150.git.andreyknvl@google.comSigned-off-by: NAndrey Konovalov <andreyknvl@google.com>
Acked-by: NMarco Elver <elver@google.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: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

During boot, all non-reserved memblock memory is exposed to page_alloc via
memblock_free_pages->__free_pages_core().  This results in
kasan_free_pages() being called, which poisons that memory.

Poisoning all that memory lengthens boot time.  The most noticeable effect
is observed with the HW_TAGS mode.  A boot-time impact may potentially
also affect systems with large amount of RAM.

This patch changes the tag-based modes to not poison the memory during the
memblock->page_alloc transition.

An exception is made for KASAN_GENERIC.  Since it marks all new memory as
accessible, not poisoning the memory released from memblock will lead to
KASAN missing invalid boot-time accesses to that memory.

With KASAN_SW_TAGS, as it uses the invalid 0xFE tag as the default tag for
all memory, it won't miss bad boot-time accesses even if the poisoning of
memblock memory is removed.

With KASAN_HW_TAGS, the default memory tags values are unspecified.
Therefore, if memblock poisoning is removed, this KASAN mode will miss the
mentioned type of boot-time bugs with a 1/16 probability.  This is taken
as an acceptable trafe-off.

Internally, the poisoning is removed as follows.  __free_pages_core() is
used when exposing fresh memory during system boot and when onlining
memory during hotplug.  This patch adds a new FPI_SKIP_KASAN_POISON flag
and passes it to __free_pages_ok() through free_pages_prepare() from
__free_pages_core().  If FPI_SKIP_KASAN_POISON is set, kasan_free_pages()
is not called.

All memory allocated normally when the boot is over keeps getting poisoned
as usual.

Link: https://lkml.kernel.org/r/a0570dc1e3a8f39a55aa343a1fc08cd5c2d4cad6.1613692950.git.andreyknvl@google.comSigned-off-by: NAndrey Konovalov <andreyknvl@google.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently, KASAN_SW_TAGS uses 0xFF as the default tag value for
unallocated memory.  The underlying idea is that since that memory hasn't
been allocated yet, it's only supposed to be dereferenced through a
pointer with the native 0xFF tag.

While this is a good idea in terms on consistency, practically it doesn't
bring any benefit.  Since the 0xFF pointer tag is a match-all tag, it
doesn't matter what tag the accessed memory has.  No accesses through
0xFF-tagged pointers are considered buggy by KASAN.

This patch changes the default tag value for unallocated memory to 0xFE,
which is the tag KASAN uses for inaccessible memory.  This doesn't affect
accesses through 0xFF-tagged pointer to this memory, but this allows KASAN
to detect wild and large out-of-bounds invalid memory accesses through
otherwise-tagged pointers.

This is a prepatory patch for the next one, which changes the tag-based
KASAN modes to not poison the boot memory.

Link: https://lkml.kernel.org/r/c8e93571c18b3528aac5eb33ade213bf133d10ad.1613692950.git.andreyknvl@google.comSigned-off-by: NAndrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We can sometimes end up with kasan_byte_accessible() being called on
non-slab memory.  For example ksize() and krealloc() may end up calling it
on KFENCE allocated memory.  In this case the memory will be tagged with
KASAN_SHADOW_INIT, which a subsequent patch ("kasan: initialize shadow to
TAG_INVALID for SW_TAGS") will set to the same value as KASAN_TAG_INVALID,
causing kasan_byte_accessible() to fail when called on non-slab memory.

This highlighted the fact that the check in kasan_byte_accessible() was
inconsistent with checks as implemented for loads and stores
(kasan_check_range() in SW tags mode and hardware-implemented checks in HW
tags mode).  kasan_check_range() does not have a check for
KASAN_TAG_INVALID, and instead has a comparison against
KASAN_SHADOW_START.  In HW tags mode, we do not have either, but we do set
TCR_EL1.TCMA which corresponds with the comparison against
KASAN_TAG_KERNEL.

Therefore, update kasan_byte_accessible() for both SW and HW tags modes to
correspond with the respective checks on loads and stores.

Link: https://linux-review.googlesource.com/id/Ic6d40803c57dcc6331bd97fbb9a60b0d38a65a36
Link: https://lkml.kernel.org/r/20210405220647.1965262-1-pcc@google.comSigned-off-by: NPeter Collingbourne <pcc@google.com>
Reviewed-by: NAndrey Konovalov <andreyknvl@gmail.com>
Reviewed-by: NMarco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

strlcpy is marked as deprecated in Documentation/process/deprecated.rst,
and there is no functional difference when the caller expects truncation
(when not checking the return value).  strscpy is relatively better as it
also avoids scanning the whole source string.

Link: https://lkml.kernel.org/r/1613970647-23272-1-git-send-email-daizhiyuan@phytium.com.cnSigned-off-by: NZhiyuan Dai <daizhiyuan@phytium.com.cn>
Acked-by: NAlexander Potapenko <glider@google.com>
Reviewed-by: NAndrey Konovalov <andreyknvl@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The script './scripts/kernel-doc -none ./include/linux/pagewalk.h' reports:

  include/linux/pagewalk.h:37: warning: cannot understand function prototype: 'struct mm_walk_ops '
  include/linux/pagewalk.h:85: warning: cannot understand function prototype: 'struct mm_walk '

A kernel-doc description for a structure requires to prefix the struct
name with the keyword 'struct'.  So, do that such that no further
kernel-doc warnings are reported for this file.

Link: https://lkml.kernel.org/r/20210322122542.15072-3-lukas.bulwahn@gmail.comSigned-off-by: NLukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ralf Ramsauer <ralf.ramsauer@oth-regensburg.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "kernel-doc and MAINTAINERS clean-up".

Roughly 900 warnings of about 21.000 kernel-doc warnings in the kernel
tree warn with 'cannot understand function prototype:', i.e., the
kernel-doc parser cannot parse the function's signature.  The majority,
about 600 cases of those, are just struct definitions following the
kernel-doc description.  Further, spot-check investigations suggest that
the authors of the specific kernel-doc descriptions simply were not
aware that the general format for a kernel-doc description for a
structure requires to prefix the struct name with the keyword 'struct',
as in 'struct struct_name - Brief description.'.  Details on kernel-doc
are at the Link below.

Without the struct keyword, kernel-doc does not check if the kernel-doc
description fits to the actual struct definition in the source code.
Fortunately, in roughly a quarter of these cases, the kernel-doc
description is actually complete wrt.  its corresponding struct
definition.  So, the trivial change adding the struct keyword will allow
us to keep the kernel-doc descriptions more consistent for future
changes, by checking for new kernel-doc warnings.

Also, some of the files in ./include/ are not assigned to a specific
MAINTAINERS section and hence have no dedicated maintainer.  So, if
needed, the files in ./include/ are also assigned to the fitting
MAINTAINERS section, as I need to identify whom to send the clean-up
patch anyway.

Here is the change from this kernel-doc janitorial work in the
./include/ directory for MEMORY MANAGEMENT.

This patch (of 2):

Commit a520110e ("mm: split out a new pagewalk.h header from mm.h")
adds a new file in ./include/linux, but misses to update MAINTAINERS
accordingly.  Hence,

  ./scripts/get_maintainers.pl include/linux/pagewalk.h

points only to lkml as general fallback for all files, whereas the
original include/linux/mm.h clearly marks this file part of MEMORY
MANAGEMENT.

Assign include/linux/pagewalk.h to MEMORY MANAGEMENT.

Link: https://lkml.kernel.org/r/20210322122542.15072-1-lukas.bulwahn@gmail.com
Link: https://lkml.kernel.org/r/20210322122542.15072-2-lukas.bulwahn@gmail.comSigned-off-by: NLukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Ralf Ramsauer <ralf.ramsauer@oth-regensburg.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

kerneldoc in include/linux/mm.h and include/linux/mm_types.h wasn't being
included in the html build.

Link: https://lkml.kernel.org/r/20210322195022.2143603-4-willy@infradead.orgSigned-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: NMike Rapoport <rppt@linux.ibm.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The kernel-doc script complains about

  include/linux/mm.h:425: warning: wrong kernel-doc identifier on line:
   * Fault flag definitions.

I don't know how to document a series of #defines, so turn these
definitions into an enum and document that instead.

Link: https://lkml.kernel.org/r/20210322195022.2143603-3-willy@infradead.orgSigned-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: NMike Rapoport <rppt@linux.ibm.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

make htmldocs reports:

  include/linux/mm.h:1341: warning: Excess function parameter 'Return' description in 'page_maybe_dma_pinned'

Fix a few other formatting nits while I'm editing this description.

Link: https://lkml.kernel.org/r/20210322195022.2143603-2-willy@infradead.orgSigned-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: NMike Rapoport <rppt@linux.ibm.com>
Reviewed-by: NJohn Hubbard <jhubbard@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

make htmldocs reports:

  include/linux/mm.h:496: warning: Function parameter or member 'flags' not described in 'fault_flag_allow_retry_first'

Add a description.

Link: https://lkml.kernel.org/r/20210322195022.2143603-1-willy@infradead.orgSigned-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Link: https://lkml.kernel.org/r/20210402202237.20334-5-urezki@gmail.comSigned-off-by: NUladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>