Vijayanand Jitta [Fri, 26 Feb 2021 01:21:31 +0000 (17:21 -0800)]
lib: stackdepot: fix ignoring return value warning
Fix the below ignoring return value warning for kstrtobool in
is_stack_depot_disabled function.
lib/stackdepot.c: In function 'is_stack_depot_disabled':
lib/stackdepot.c:154:2: warning: ignoring return value of 'kstrtobool'
declared with attribute 'warn_unused_result' [-Wunused-result]
Link: https://lkml.kernel.org/r/1612163048-28026-1-git-send-email-vjitta@codeaurora.org Fixes: b9779abb09a8 ("lib: stackdepot: add support to disable stack depot") Signed-off-by: Vijayanand Jitta <vjitta@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vijayanand Jitta [Fri, 26 Feb 2021 01:21:27 +0000 (17:21 -0800)]
lib: stackdepot: add support to disable stack depot
Add a kernel parameter stack_depot_disable to disable stack depot. So
that stack hash table doesn't consume any memory when stack depot is
disabled.
The use case is CONFIG_PAGE_OWNER without page_owner=on. Without this
patch, stackdepot will consume the memory for the hashtable. By default,
it's 8M which is never trivial.
With this option, in CONFIG_PAGE_OWNER configured system, page_owner=off,
stack_depot_disable in kernel command line, we could save the wasted
memory for the hashtable.
Yogesh Lal [Fri, 26 Feb 2021 01:21:24 +0000 (17:21 -0800)]
lib: stackdepot: add support to configure STACK_HASH_SIZE
Use CONFIG_STACK_HASH_ORDER to configure STACK_HASH_SIZE.
Aim is to have configurable value for STACK_HASH_SIZE,
so depend on use case one can configure it.
One example is of Page Owner, CONFIG_PAGE_OWNER works only if
page_owner=on via kernel parameter on CONFIG_PAGE_OWNER configured system.
Thus, unless admin enable it via command line option, the stackdepot will
just waste 8M memory without any customer.
Making it configurable and use lower value helps to enable features like
CONFIG_PAGE_OWNER without any significant overhead.
Link: https://lkml.kernel.org/r/1611749198-24316-1-git-send-email-vjitta@codeaurora.org Signed-off-by: Yogesh Lal <ylal@codeaurora.org> Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org> Signed-off-by: Vijayanand Jitta <vjitta@codeaurora.org> Reviewed-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Francis Laniel [Fri, 26 Feb 2021 01:21:20 +0000 (17:21 -0800)]
string.h: move fortified functions definitions in a dedicated header.
This patch adds fortify-string.h to contain fortified functions
definitions. Thus, the code is more separated and compile time is
approximately 1% faster for people who do not set CONFIG_FORTIFY_SOURCE.
Vlastimil Babka [Fri, 26 Feb 2021 01:21:14 +0000 (17:21 -0800)]
MAINTAINERS: add uapi directories to API/ABI section
Let's add include/uapi/ and arch/*/include/uapi/ to API/ABI section, so
that for patches modifying them, get_maintainers.pl suggests CCing
linux-api@ so people don't forget.
Link: https://lkml.kernel.org/r/20210217174745.13591-1-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reported-by: David Hildenbrand <david@redhat.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Randy Dunlap [Fri, 26 Feb 2021 01:20:56 +0000 (17:20 -0800)]
include/linux: remove repeated words
Drop the doubled word "for" in a comment. {firewire-cdev.h}
Drop the doubled word "in" in a comment. {input.h}
Drop the doubled word "a" in a comment. {mdev.h}
Drop the doubled word "the" in a comment. {ptrace.h}
Link: https://lkml.kernel.org/r/20210126232444.22861-1-rdunlap@infradead.org Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Stefan Richter <stefanr@s5r6.in-berlin.de> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Kirti Wankhede <kwankhede@nvidia.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Lin Feng [Fri, 26 Feb 2021 01:20:53 +0000 (17:20 -0800)]
sysctl.c: fix underflow value setting risk in vm_table
Apart from subsystem specific .proc_handler handler, all ctl_tables with
extra1 and extra2 members set should use proc_dointvec_minmax instead of
proc_dointvec, or the limit set in extra* never work and potentially echo
underflow values(negative numbers) is likely make system unstable.
Especially vfs_cache_pressure and zone_reclaim_mode, -1 is apparently not
a valid value, but we can set to them. And then kernel may crash.
# echo -1 > /proc/sys/vm/vfs_cache_pressure
Link: https://lkml.kernel.org/r/20201223105535.2875-1-linf@wangsu.com Signed-off-by: Lin Feng <linf@wangsu.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Josef Bacik [Fri, 26 Feb 2021 01:20:49 +0000 (17:20 -0800)]
proc: use kvzalloc for our kernel buffer
Since
sysctl: pass kernel pointers to ->proc_handler
we have been pre-allocating a buffer to copy the data from the proc
handlers into, and then copying that to userspace. The problem is this
just blindly kzalloc()'s the buffer size passed in from the read, which in
the case of our 'cat' binary was 64kib. Order-4 allocations are not
awesome, and since we can potentially allocate up to our maximum order, so
use kvzalloc for these buffers.
[willy@infradead.org: changelog tweaks]
Link: https://lkml.kernel.org/r/6345270a2c1160b89dd5e6715461f388176899d1.1612972413.git.josef@toxicpanda.com Fixes: 32927393dc1c ("sysctl: pass kernel pointers to ->proc_handler") Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Alexey Dobriyan <adobriyan@gmail.com> CC: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Helge Deller [Fri, 26 Feb 2021 01:20:45 +0000 (17:20 -0800)]
proc/wchan: use printk format instead of lookup_symbol_name()
To resolve the symbol fuction name for wchan, use the printk format
specifier %ps instead of manually looking up the symbol function name
via lookup_symbol_name().
Andrey Konovalov [Fri, 26 Feb 2021 01:20:31 +0000 (17:20 -0800)]
arm64: kasan: simplify and inline MTE functions
This change provides a simpler implementation of mte_get_mem_tag(),
mte_get_random_tag(), and mte_set_mem_tag_range().
Simplifications include removing system_supports_mte() checks as these
functions are onlye called from KASAN runtime that had already checked
system_supports_mte(). Besides that, size and address alignment checks
are removed from mte_set_mem_tag_range(), as KASAN now does those.
This change also moves these functions into the asm/mte-kasan.h header and
implements mte_set_mem_tag_range() via inline assembly to avoid
unnecessary functions calls.
[vincenzo.frascino@arm.com: fix warning in mte_get_random_tag()] Link: https://lkml.kernel.org/r/20210211152208.23811-1-vincenzo.frascino@arm.com Link: https://lkml.kernel.org/r/a26121b294fdf76e369cb7a74351d1c03a908930.1612546384.git.andreyknvl@google.com Co-developed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> 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: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrey Konovalov [Fri, 26 Feb 2021 01:20:27 +0000 (17:20 -0800)]
kasan: ensure poisoning size alignment
A previous changes d99f6a10c161 ("kasan: don't round_up too much")
attempted to simplify the code by adding a round_up(size) call into
kasan_poison(). While this allows to have less round_up() calls around
the code, this results in round_up() being called multiple times.
This patch removes round_up() of size from kasan_poison() and ensures that
all callers round_up() the size explicitly. This patch also adds
WARN_ON() alignment checks for address and size to kasan_poison() and
kasan_unpoison().
Link: https://lkml.kernel.org/r/3ffe8d4a246ae67a8b5e91f65bf98cd7cba9d7b9.1612546384.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco 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: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrey Konovalov [Fri, 26 Feb 2021 01:20:23 +0000 (17:20 -0800)]
kasan, mm: optimize krealloc poisoning
Currently, krealloc() always calls ksize(), which unpoisons the whole
object including the redzone. This is inefficient, as kasan_krealloc()
repoisons the redzone for objects that fit into the same buffer.
This patch changes krealloc() instrumentation to use uninstrumented
__ksize() that doesn't unpoison the memory. Instead, kasan_kreallos() is
changed to unpoison the memory excluding the redzone.
For objects that don't fit into the old allocation, this patch disables
KASAN accessibility checks when copying memory into a new object instead
of unpoisoning it.
Link: https://lkml.kernel.org/r/9bef90327c9cb109d736c40115684fd32f49e6b0.1612546384.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco 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: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrey Konovalov [Fri, 26 Feb 2021 01:20:19 +0000 (17:20 -0800)]
kasan, mm: fail krealloc on freed objects
Currently, if krealloc() is called on a freed object with KASAN enabled,
it allocates and returns a new object, but doesn't copy any memory from
the old one as ksize() returns 0. This makes the caller believe that
krealloc() succeeded (KASAN report is printed though).
This patch adds an accessibility check into __do_krealloc(). If the check
fails, krealloc() returns NULL. This check duplicates the one in ksize();
this is fixed in the following patch.
This patch also adds a KASAN-KUnit test to check krealloc() behaviour when
it's called on a freed object.
Link: https://lkml.kernel.org/r/cbcf7b02be0a1ca11de4f833f2ff0b3f2c9b00c8.1612546384.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco 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: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrey Konovalov [Fri, 26 Feb 2021 01:20:15 +0000 (17:20 -0800)]
kasan: rework krealloc tests
This patch reworks KASAN-KUnit tests for krealloc() to:
1. Check both slab and page_alloc based krealloc() implementations.
2. Allow at least one full granule to fit between old and new sizes for
each KASAN mode, and check accesses to that granule accordingly.
Link: https://lkml.kernel.org/r/c707f128a2bb9f2f05185d1eb52192cf179cf4fa.1612546384.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco 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: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrey Konovalov [Fri, 26 Feb 2021 01:20:07 +0000 (17:20 -0800)]
kasan: clean up setting free info in kasan_slab_free
Put kasan_stack_collection_enabled() check and kasan_set_free_info() calls
next to each other.
The way this was previously implemented was a minor optimization that
relied of the the fact that kasan_stack_collection_enabled() is always
true for generic KASAN. The confusion that this brings outweights saving
a few instructions.
Link: https://lkml.kernel.org/r/f838e249be5ab5810bf54a36ef5072cfd80e2da7.1612546384.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco 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: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrey Konovalov [Fri, 26 Feb 2021 01:20:03 +0000 (17:20 -0800)]
kasan: optimize large kmalloc poisoning
Similarly to kasan_kmalloc(), kasan_kmalloc_large() doesn't need to
unpoison the object as it as already unpoisoned by alloc_pages() (or by
ksize() for krealloc()).
This patch changes kasan_kmalloc_large() to only poison the redzone.
Link: https://lkml.kernel.org/r/33dee5aac0e550ad7f8e26f590c9b02c6129b4a3.1612546384.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco 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: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrey Konovalov [Fri, 26 Feb 2021 01:19:59 +0000 (17:19 -0800)]
kasan, mm: optimize kmalloc poisoning
For allocations from kmalloc caches, kasan_kmalloc() always follows
kasan_slab_alloc(). Currenly, both of them unpoison the whole object,
which is unnecessary.
This patch provides separate implementations for both annotations:
kasan_slab_alloc() unpoisons the whole object, and kasan_kmalloc() only
poisons the redzone.
For generic KASAN, the redzone start might not be aligned to
KASAN_GRANULE_SIZE. Therefore, the poisoning is split in two parts:
kasan_poison_last_granule() poisons the unaligned part, and then
kasan_poison() poisons the rest.
This patch also clarifies alignment guarantees of each of the poisoning
functions and drops the unnecessary round_up() call for redzone_end.
With this change, the early SLUB cache annotation needs to be changed to
kasan_slab_alloc(), as kasan_kmalloc() doesn't unpoison objects now. The
number of poisoned bytes for objects in this cache stays the same, as
kmem_cache_node->object_size is equal to sizeof(struct kmem_cache_node).
Link: https://lkml.kernel.org/r/7e3961cb52be380bc412860332063f5f7ce10d13.1612546384.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco 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: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrey Konovalov [Fri, 26 Feb 2021 01:19:55 +0000 (17:19 -0800)]
kasan, mm: don't save alloc stacks twice
Patch series "kasan: optimizations and fixes for HW_TAGS", v4.
This patchset makes the HW_TAGS mode more efficient, mostly by reworking
poisoning approaches and simplifying/inlining some internal helpers.
With this change, the overhead of HW_TAGS annotations excluding setting
and checking memory tags is ~3%. The performance impact caused by tags
will be unknown until we have hardware that supports MTE.
As a side-effect, this patchset speeds up generic KASAN by ~15%.
This patch (of 13):
Currently KASAN saves allocation stacks in both kasan_slab_alloc() and
kasan_kmalloc() annotations. This patch changes KASAN to save allocation
stacks for slab objects from kmalloc caches in kasan_kmalloc() only, and
stacks for other slab objects in kasan_slab_alloc() only.
This change requires ____kasan_kmalloc() knowing whether the object
belongs to a kmalloc cache. This is implemented by adding a flag field to
the kasan_info structure. That flag is only set for kmalloc caches via a
new kasan_cache_create_kmalloc() annotation.
Link: https://lkml.kernel.org/r/cover.1612546384.git.andreyknvl@google.com Link: https://lkml.kernel.org/r/7c673ebca8d00f40a7ad6f04ab9a2bddeeae2097.1612546384.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.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: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make it possible to trace KASAN error reporting. A good usecase is
watching for trace events from the userspace to detect and process memory
corruption reports from the kernel.
Link: https://lkml.kernel.org/r/20210121131915.1331302-4-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Suggested-by: Marco Elver <elver@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make it possible to trace KFENCE error reporting. A good usecase is
watching for trace events from the userspace to detect and process memory
corruption reports from the kernel.
Link: https://lkml.kernel.org/r/20210121131915.1331302-3-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Suggested-by: Marco Elver <elver@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "Add error_report_end tracepoint to KFENCE and KASAN", v3.
This patchset adds a tracepoint, error_repor_end, that is to be used by
KFENCE, KASAN, and potentially other bug detection tools, when they print
an error report. One of the possible use cases is userspace collection of
kernel error reports: interested parties can subscribe to the tracing
event via tracefs, and get notified when an error report occurs.
This patch (of 3):
Introduce error_report_end tracepoint. It can be used in debugging tools
like KASAN, KFENCE, etc. to provide extensions to the error reporting
mechanisms (e.g. allow tests hook into error reporting, ease error report
collection from production kernels). Another benefit would be making use
of ftrace for debugging or benchmarking the tools themselves.
Should we need it, the tracepoint name leaves us with the possibility to
introduce a complementary error_report_start tracepoint in the future.
Marco Elver [Fri, 26 Feb 2021 01:19:40 +0000 (17:19 -0800)]
kfence: report sensitive information based on no_hash_pointers
We cannot rely on CONFIG_DEBUG_KERNEL to decide if we're running a "debug
kernel" where we can safely show potentially sensitive information in the
kernel log.
Instead, simply rely on the newly introduced "no_hash_pointers" to print
unhashed kernel pointers, as well as decide if our reports can include
other potentially sensitive information such as registers and corrupted
bytes.
Link: https://lkml.kernel.org/r/20210223082043.1972742-1-elver@google.com Signed-off-by: Marco Elver <elver@google.com> Cc: Timur Tabi <timur@kernel.org> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Marco Elver [Fri, 26 Feb 2021 01:19:31 +0000 (17:19 -0800)]
kfence: add test suite
Add KFENCE test suite, testing various error detection scenarios. Makes
use of KUnit for test organization. Since KFENCE's interface to obtain
error reports is via the console, the test verifies that KFENCE outputs
expected reports to the console.
[elver@google.com: fix typo in test] Link: https://lkml.kernel.org/r/X9lHQExmHGvETxY4@elver.google.com
[elver@google.com: show access type in report] Link: https://lkml.kernel.org/r/20210111091544.3287013-2-elver@google.com Link: https://lkml.kernel.org/r/20201103175841.3495947-9-elver@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Signed-off-by: Marco Elver <elver@google.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Co-developed-by: Alexander Potapenko <glider@google.com> Reviewed-by: Jann Horn <jannh@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christopher Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hillf Danton <hdanton@sina.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joern Engel <joern@purestorage.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kees Cook <keescook@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: SeongJae Park <sjpark@amazon.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make KFENCE compatible with KASAN. Currently this helps test KFENCE
itself, where KASAN can catch potential corruptions to KFENCE state, or
other corruptions that may be a result of freepointer corruptions in the
main allocators.
[akpm@linux-foundation.org: merge fixup]
[andreyknvl@google.com: untag addresses for KFENCE] Link: https://lkml.kernel.org/r/9dc196006921b191d25d10f6e611316db7da2efc.1611946152.git.andreyknvl@google.com Link: https://lkml.kernel.org/r/20201103175841.3495947-7-elver@google.com Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Alexander Potapenko <glider@google.com> Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Jann Horn <jannh@google.com> Co-developed-by: Marco Elver <elver@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christopher Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hillf Danton <hdanton@sina.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joern Engel <joern@purestorage.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kees Cook <keescook@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: SeongJae Park <sjpark@amazon.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To pass the originally requested size to KFENCE, add an argument
'orig_size' to slab_alloc*(). The additional argument is required to
preserve the requested original size for kmalloc() allocations, which
uses size classes (e.g. an allocation of 272 bytes will return an object
of size 512). Therefore, kmem_cache::size does not represent the
kmalloc-caller's requested size, and we must introduce the argument
'orig_size' to propagate the originally requested size to KFENCE.
Without the originally requested size, we would not be able to detect
out-of-bounds accesses for objects placed at the end of a KFENCE object
page if that object is not equal to the kmalloc-size class it was
bucketed into.
When KFENCE is disabled, there is no additional overhead, since
slab_alloc*() functions are __always_inline.
Link: https://lkml.kernel.org/r/20201103175841.3495947-6-elver@google.com Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Alexander Potapenko <glider@google.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Jann Horn <jannh@google.com> Co-developed-by: Marco Elver <elver@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christopher Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hillf Danton <hdanton@sina.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joern Engel <joern@purestorage.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kees Cook <keescook@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: SeongJae Park <sjpark@amazon.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To pass the originally requested size to KFENCE, add an argument
'orig_size' to slab_alloc*(). The additional argument is required to
preserve the requested original size for kmalloc() allocations, which
uses size classes (e.g. an allocation of 272 bytes will return an object
of size 512). Therefore, kmem_cache::size does not represent the
kmalloc-caller's requested size, and we must introduce the argument
'orig_size' to propagate the originally requested size to KFENCE.
Without the originally requested size, we would not be able to detect
out-of-bounds accesses for objects placed at the end of a KFENCE object
page if that object is not equal to the kmalloc-size class it was
bucketed into.
When KFENCE is disabled, there is no additional overhead, since
slab_alloc*() functions are __always_inline.
Link: https://lkml.kernel.org/r/20201103175841.3495947-5-elver@google.com Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Alexander Potapenko <glider@google.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Co-developed-by: Marco 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: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hillf Danton <hdanton@sina.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Joern Engel <joern@purestorage.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kees Cook <keescook@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: SeongJae Park <sjpark@amazon.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Marco Elver [Fri, 26 Feb 2021 01:19:08 +0000 (17:19 -0800)]
kfence: use pt_regs to generate stack trace on faults
Instead of removing the fault handling portion of the stack trace based on
the fault handler's name, just use struct pt_regs directly.
Change kfence_handle_page_fault() to take a struct pt_regs, and plumb it
through to kfence_report_error() for out-of-bounds, use-after-free, or
invalid access errors, where pt_regs is used to generate the stack trace.
If the kernel is a DEBUG_KERNEL, also show registers for more information.
Link: https://lkml.kernel.org/r/20201105092133.2075331-1-elver@google.com Signed-off-by: Marco Elver <elver@google.com> Suggested-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Marco Elver [Fri, 26 Feb 2021 01:19:03 +0000 (17:19 -0800)]
arm64, kfence: enable KFENCE for ARM64
Add architecture specific implementation details for KFENCE and enable
KFENCE for the arm64 architecture. In particular, this implements the
required interface in <asm/kfence.h>.
KFENCE requires that attributes for pages from its memory pool can
individually be set. Therefore, force the entire linear map to be mapped
at page granularity. Doing so may result in extra memory allocated for
page tables in case rodata=full is not set; however, currently
CONFIG_RODATA_FULL_DEFAULT_ENABLED=y is the default, and the common case
is therefore not affected by this change.
[elver@google.com: add missing copyright and description header] Link: https://lkml.kernel.org/r/20210118092159.145934-3-elver@google.com Link: https://lkml.kernel.org/r/20201103175841.3495947-4-elver@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Signed-off-by: Marco Elver <elver@google.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Co-developed-by: Alexander Potapenko <glider@google.com> Reviewed-by: Jann Horn <jannh@google.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christopher Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hillf Danton <hdanton@sina.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joern Engel <joern@purestorage.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kees Cook <keescook@chromium.org> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: SeongJae Park <sjpark@amazon.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add architecture specific implementation details for KFENCE and enable
KFENCE for the x86 architecture. In particular, this implements the
required interface in <asm/kfence.h> for setting up the pool and
providing helper functions for protecting and unprotecting pages.
For x86, we need to ensure that the pool uses 4K pages, which is done
using the set_memory_4k() helper function.
[elver@google.com: add missing copyright and description header] Link: https://lkml.kernel.org/r/20210118092159.145934-2-elver@google.com Link: https://lkml.kernel.org/r/20201103175841.3495947-3-elver@google.com Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Alexander Potapenko <glider@google.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Co-developed-by: Marco Elver <elver@google.com> Reviewed-by: Jann Horn <jannh@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christopher Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hillf Danton <hdanton@sina.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joern Engel <joern@purestorage.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kees Cook <keescook@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: SeongJae Park <sjpark@amazon.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "KFENCE: A low-overhead sampling-based memory safety error detector", v7.
This adds the Kernel Electric-Fence (KFENCE) infrastructure. KFENCE is a
low-overhead sampling-based memory safety error detector of heap
use-after-free, invalid-free, and out-of-bounds access errors. This
series enables KFENCE for the x86 and arm64 architectures, and adds
KFENCE hooks to the SLAB and SLUB allocators.
KFENCE is designed to be enabled in production kernels, and has near
zero performance overhead. Compared to KASAN, KFENCE trades performance
for precision. The main motivation behind KFENCE's design, is that with
enough total uptime KFENCE will detect bugs in code paths not typically
exercised by non-production test workloads. One way to quickly achieve a
large enough total uptime is when the tool is deployed across a large
fleet of machines.
KFENCE objects each reside on a dedicated page, at either the left or
right page boundaries. The pages to the left and right of the object
page are "guard pages", whose attributes are changed to a protected
state, and cause page faults on any attempted access to them. Such page
faults are then intercepted by KFENCE, which handles the fault
gracefully by reporting a memory access error.
Guarded allocations are set up based on a sample interval (can be set
via kfence.sample_interval). After expiration of the sample interval,
the next allocation through the main allocator (SLAB or SLUB) returns a
guarded allocation from the KFENCE object pool. At this point, the timer
is reset, and the next allocation is set up after the expiration of the
interval.
To enable/disable a KFENCE allocation through the main allocator's
fast-path without overhead, KFENCE relies on static branches via the
static keys infrastructure. The static branch is toggled to redirect the
allocation to KFENCE.
The KFENCE memory pool is of fixed size, and if the pool is exhausted no
further KFENCE allocations occur. The default config is conservative
with only 255 objects, resulting in a pool size of 2 MiB (with 4 KiB
pages).
We have verified by running synthetic benchmarks (sysbench I/O,
hackbench) and production server-workload benchmarks that a kernel with
KFENCE (using sample intervals 100-500ms) is performance-neutral
compared to a non-KFENCE baseline kernel.
KFENCE is inspired by GWP-ASan [1], a userspace tool with similar
properties. The name "KFENCE" is a homage to the Electric Fence Malloc
Debugger [2].
For more details, see Documentation/dev-tools/kfence.rst added in the
series -- also viewable here:
This adds the Kernel Electric-Fence (KFENCE) infrastructure. KFENCE is a
low-overhead sampling-based memory safety error detector of heap
use-after-free, invalid-free, and out-of-bounds access errors.
KFENCE is designed to be enabled in production kernels, and has near
zero performance overhead. Compared to KASAN, KFENCE trades performance
for precision. The main motivation behind KFENCE's design, is that with
enough total uptime KFENCE will detect bugs in code paths not typically
exercised by non-production test workloads. One way to quickly achieve a
large enough total uptime is when the tool is deployed across a large
fleet of machines.
KFENCE objects each reside on a dedicated page, at either the left or
right page boundaries. The pages to the left and right of the object
page are "guard pages", whose attributes are changed to a protected
state, and cause page faults on any attempted access to them. Such page
faults are then intercepted by KFENCE, which handles the fault
gracefully by reporting a memory access error. To detect out-of-bounds
writes to memory within the object's page itself, KFENCE also uses
pattern-based redzones. The following figure illustrates the page
layout:
---+-----------+-----------+-----------+-----------+-----------+---
| xxxxxxxxx | O : | xxxxxxxxx | : O | xxxxxxxxx |
| xxxxxxxxx | B : | xxxxxxxxx | : B | xxxxxxxxx |
| x GUARD x | J : RED- | x GUARD x | RED- : J | x GUARD x |
| xxxxxxxxx | E : ZONE | xxxxxxxxx | ZONE : E | xxxxxxxxx |
| xxxxxxxxx | C : | xxxxxxxxx | : C | xxxxxxxxx |
| xxxxxxxxx | T : | xxxxxxxxx | : T | xxxxxxxxx |
---+-----------+-----------+-----------+-----------+-----------+---
Guarded allocations are set up based on a sample interval (can be set
via kfence.sample_interval). After expiration of the sample interval, a
guarded allocation from the KFENCE object pool is returned to the main
allocator (SLAB or SLUB). At this point, the timer is reset, and the
next allocation is set up after the expiration of the interval.
To enable/disable a KFENCE allocation through the main allocator's
fast-path without overhead, KFENCE relies on static branches via the
static keys infrastructure. The static branch is toggled to redirect the
allocation to KFENCE. To date, we have verified by running synthetic
benchmarks (sysbench I/O, hackbench) that a kernel compiled with KFENCE
is performance-neutral compared to the non-KFENCE baseline.
For more details, see Documentation/dev-tools/kfence.rst (added later in
the series).
[elver@google.com: fix parameter description for kfence_object_start()] Link: https://lkml.kernel.org/r/20201106092149.GA2851373@elver.google.com
[elver@google.com: avoid stalling work queue task without allocations] Link: https://lkml.kernel.org/r/CADYN=9J0DQhizAGB0-jz4HOBBh+05kMBXb4c0cXMS7Qi5NAJiw@mail.gmail.com Link: https://lkml.kernel.org/r/20201110135320.3309507-1-elver@google.com
[elver@google.com: fix potential deadlock due to wake_up()] Link: https://lkml.kernel.org/r/000000000000c0645805b7f982e4@google.com Link: https://lkml.kernel.org/r/20210104130749.1768991-1-elver@google.com
[elver@google.com: add option to use KFENCE without static keys] Link: https://lkml.kernel.org/r/20210111091544.3287013-1-elver@google.com
[elver@google.com: add missing copyright and description headers] Link: https://lkml.kernel.org/r/20210118092159.145934-1-elver@google.com Link: https://lkml.kernel.org/r/20201103175841.3495947-2-elver@google.com Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Alexander Potapenko <glider@google.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: SeongJae Park <sjpark@amazon.de> Co-developed-by: Marco Elver <elver@google.com> Reviewed-by: Jann Horn <jannh@google.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christopher Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hillf Danton <hdanton@sina.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Joern Engel <joern@purestorage.com> Cc: Kees Cook <keescook@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Guo Ren [Fri, 26 Feb 2021 01:18:38 +0000 (17:18 -0800)]
mm: page-flags.h: Typo fix (It -> If)
The "If" was wrongly spelled as "It".
Link: https://lkml.kernel.org/r/1608959036-91409-1-git-send-email-guoren@kernel.org Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Steven Price <steven.price@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rokudo Yan [Fri, 26 Feb 2021 01:18:31 +0000 (17:18 -0800)]
zsmalloc: account the number of compacted pages correctly
There exists multiple path may do zram compaction concurrently.
1. auto-compaction triggered during memory reclaim
2. userspace utils write zram<id>/compaction node
So, multiple threads may call zs_shrinker_scan/zs_compact concurrently.
But pages_compacted is a per zsmalloc pool variable and modification
of the variable is not serialized(through under class->lock).
There are two issues here:
1. the pages_compacted may not equal to total number of pages
freed(due to concurrently add).
2. zs_shrinker_scan may not return the correct number of pages
freed(issued by current shrinker).
The fix is simple:
1. account the number of pages freed in zs_compact locally.
2. use actomic variable pages_compacted to accumulate total number.
Link: https://lkml.kernel.org/r/20210202122235.26885-1-wu-yan@tcl.com Fixes: 860c707dca155a56 ("zsmalloc: account the number of compacted pages") Signed-off-by: Rokudo Yan <wu-yan@tcl.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Miaohe Lin [Fri, 26 Feb 2021 01:18:27 +0000 (17:18 -0800)]
mm/zsmalloc.c: convert to use kmem_cache_zalloc in cache_alloc_zspage()
We always memset the zspage allocated via cache_alloc_zspage. So it's
more convenient to use kmem_cache_zalloc in cache_alloc_zspage than caller
do it manually.
Link: https://lkml.kernel.org/r/20210114120032.25885-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tian Tao [Fri, 26 Feb 2021 01:18:22 +0000 (17:18 -0800)]
mm: set the sleep_mapped to true for zbud and z3fold
zpool driver adds a flag to indicate whether the zpool driver can enter an
atomic context after mapping. This patch sets it true for z3fold and
zbud.
Link: https://lkml.kernel.org/r/1611035683-12732-3-git-send-email-tiantao6@hisilicon.com Signed-off-by: Tian Tao <tiantao6@hisilicon.com> Reviewed-by: Vitaly Wool <vitaly.wool@konsulko.com> Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reported-by: Mike Galbraith <efault@gmx.de> Cc: Seth Jennings <sjenning@redhat.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Barry Song <song.bao.hua@hisilicon.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tian Tao [Fri, 26 Feb 2021 01:18:17 +0000 (17:18 -0800)]
mm/zswap: add the flag can_sleep_mapped
Patch series "Fix the compatibility of zsmalloc and zswap".
Patch #1 adds a flag to zpool, then zswap used to determine if zpool
drivers such as zbud/z3fold/zsmalloc will enter an atomic context after
mapping.
The difference between zbud/z3fold and zsmalloc is that zsmalloc requires
an atomic context that since its map function holds a preempt-disabled,
but zbud/z3fold don't require an atomic context. So patch #2 sets flag
sleep_mapped to true indicating that zbud/z3fold can sleep after mapping.
zsmalloc didn't support sleep after mapping, so don't set that flag to
true.
This patch (of 2):
Add a flag to zpool, named is "can_sleep_mapped", and have it set true for
zbud/z3fold, not set this flag for zsmalloc, so its default value is
false. Then zswap could go the current path if the flag is true; and if
it's false, copy data from src to a temporary buffer, then unmap the
handle, take the mutex, process the buffer instead of src to avoid
sleeping function called from atomic context.
Miaohe Lin [Fri, 26 Feb 2021 01:18:09 +0000 (17:18 -0800)]
mm/rmap: fix potential pte_unmap on an not mapped pte
For PMD-mapped page (usually THP), pvmw->pte is NULL. For PTE-mapped THP,
pvmw->pte is mapped. But for HugeTLB pages, pvmw->pte is not mapped and
set to the relevant page table entry. So in page_vma_mapped_walk_done(),
we may do pte_unmap() for HugeTLB pte which is not mapped. Fix this by
checking pvmw->page against PageHuge before trying to do pte_unmap().
Link: https://lkml.kernel.org/r/20210127093349.39081-1-linmiaohe@huawei.com Fixes: ace71a19cec5 ("mm: introduce page_vma_mapped_walk()") Signed-off-by: Hongxiang Lou <louhongxiang@huawei.com> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Cc: Kees Cook <keescook@chromium.org> Cc: Nathan Chancellor <natechancellor@gmail.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Michel Lespinasse <walken@google.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Brian Geffon <bgeffon@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Miaohe Lin [Fri, 26 Feb 2021 01:18:06 +0000 (17:18 -0800)]
mm/rmap: correct obsolete comment of page_get_anon_vma()
Since commit 746b18d421da ("mm: use refcounts for page_lock_anon_vma()"),
page_lock_anon_vma() is renamed to page_get_anon_vma() and converted to
return a refcount increased anon_vma. But it forgot to change the
relevant comment.
Link: https://lkml.kernel.org/r/20210203093215.31990-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Miaohe Lin [Fri, 26 Feb 2021 01:18:03 +0000 (17:18 -0800)]
mm/rmap: use page_not_mapped in try_to_unmap()
page_mapcount_is_zero() calculates accurately how many mappings a hugepage
has in order to check against 0 only. This is a waste of cpu time. We
can do this via page_not_mapped() to save some possible atomic_read
cycles. Remove the function page_mapcount_is_zero() as it's not used
anymore and move page_not_mapped() above try_to_unmap() to avoid
identifier undeclared compilation error.
Miaohe Lin [Fri, 26 Feb 2021 01:17:59 +0000 (17:17 -0800)]
mm/rmap: fix obsolete comment in __page_check_anon_rmap()
Commit 21333b2b66b8 ("ksm: no debug in page_dup_rmap()") has reverted
page_dup_rmap() to an inline atomic_inc of mapcount. So page_dup_rmap()
does not call __page_check_anon_rmap() anymore.
Miaohe Lin [Fri, 26 Feb 2021 01:17:53 +0000 (17:17 -0800)]
mm/rmap: correct some obsolete comments of anon_vma
commit 2b575eb64f7a ("mm: convert anon_vma->lock to a mutex") changed
spinlock used to serialize access to vma list to mutex. And further, the
commit 5a505085f043 ("mm/rmap: Convert the struct anon_vma::mutex to an
rwsem") converted the mutex to an rwsem for solving scalability problem.
So replace spinlock with rwsem to make comment uptodate.
Link: https://lkml.kernel.org/r/20210123072459.25903-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Rik van Riel <riel@surriel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Miaohe Lin [Fri, 26 Feb 2021 01:17:49 +0000 (17:17 -0800)]
mm/mlock: stop counting mlocked pages when none vma is found
There will be no vma satisfies addr < vm_end when find_vma() returns NULL.
Thus it's meaningless to traverse the vma list below because we can't
find any vma to count mlocked pages. Stop counting mlocked pages in this
case to save some vma list traversal cycles.
Link: https://lkml.kernel.org/r/20210204110705.17586-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
virtio-mem: check against mhp_get_pluggable_range() which memory we can hotplug
Right now, we only check against MAX_PHYSMEM_BITS - but turns out there
are more restrictions of which memory we can actually hotplug, especially
om arm64 or s390x once we support them: we might receive something like
-E2BIG or -ERANGE from add_memory_driver_managed(), stopping device
operation.
So, check right when initializing the device which memory we can add,
warning the user. Try only adding actually pluggable ranges: in the worst
case, no memory provided by our device is pluggable.
In the usual case, we expect all device memory to be pluggable, and in
corner cases only some memory at the end of the device-managed memory
region to not be pluggable.
Link: https://lkml.kernel.org/r/1612149902-7867-5-git-send-email-anshuman.khandual@arm.com Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: teawater <teawaterz@linux.alibaba.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Pankaj Gupta <pankaj.gupta@cloud.ionos.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This overrides arch_get_mappabble_range() on s390 platform which will be
used with recently added generic framework. It modifies the existing
range check in vmem_add_mapping() using arch_get_mappable_range(). It
also adds a VM_BUG_ON() check that would ensure that mhp_range_allowed()
has already been called on the hotplug path.
Link: https://lkml.kernel.org/r/1612149902-7867-4-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pankaj Gupta <pankaj.gupta@cloud.ionos.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: teawater <teawaterz@linux.alibaba.com> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This overrides arch_get_mappable_range() on arm64 platform which will be
used with recently added generic framework. It drops
inside_linear_region() and subsequent check in arch_add_memory() which are
no longer required. It also adds a VM_BUG_ON() check that would ensure
that mhp_range_allowed() has already been called.
Link: https://lkml.kernel.org/r/1612149902-7867-3-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pankaj Gupta <pankaj.gupta@cloud.ionos.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: teawater <teawaterz@linux.alibaba.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/memory_hotplug: prevalidate the address range being added with platform
Patch series "mm/memory_hotplug: Pre-validate the address range with platform", v5.
This series adds a mechanism allowing platforms to weigh in and
prevalidate incoming address range before proceeding further with the
memory hotplug. This helps prevent potential platform errors for the
given address range, down the hotplug call chain, which inevitably fails
the hotplug itself.
This mechanism was suggested by David Hildenbrand during another
discussion with respect to a memory hotplug fix on arm64 platform.
This mechanism focuses on the addressibility aspect and not [sub] section
alignment aspect. Hence check_hotplug_memory_range() and check_pfn_span()
have been left unchanged.
This patch (of 4):
This introduces mhp_range_allowed() which can be called in various memory
hotplug paths to prevalidate the address range which is being added, with
the platform. Then mhp_range_allowed() calls mhp_get_pluggable_range()
which provides applicable address range depending on whether linear
mapping is required or not. For ranges that require linear mapping, it
calls a new arch callback arch_get_mappable_range() which the platform can
override. So the new callback, in turn provides the platform an
opportunity to configure acceptable memory hotplug address ranges in case
there are constraints.
This mechanism will help prevent platform specific errors deep down during
hotplug calls. This drops now redundant
check_hotplug_memory_addressable() check in __add_pages() but instead adds
a VM_BUG_ON() check which would ensure that the range has been validated
with mhp_range_allowed() earlier in the call chain. Besides
mhp_get_pluggable_range() also can be used by potential memory hotplug
callers to avail the allowed physical range which would go through on a
given platform.
This does not really add any new range check in generic memory hotplug but
instead compensates for lost checks in arch_add_memory() where applicable
and check_hotplug_memory_addressable(), with unified mhp_range_allowed().
[akpm@linux-foundation.org: make pagemap_range() return -EINVAL when mhp_range_allowed() fails]
Link: https://lkml.kernel.org/r/1612149902-7867-1-git-send-email-anshuman.khandual@arm.com Link: https://lkml.kernel.org/r/1612149902-7867-2-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Suggested-by: David Hildenbrand <david@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> # s390 Cc: Will Deacon <will@kernel.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Pankaj Gupta <pankaj.gupta@cloud.ionos.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: teawater <teawaterz@linux.alibaba.com> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Documentation: sysfs/memory: clarify some memory block device properties
In commit 53cdc1cb29e8 ("drivers/base/memory.c: indicate all memory blocks
as removable") we changed the output of the "removable" property of memory
devices to return "1" if and only if the kernel supports memory offlining.
Let's update documentation, stating that the interface is legacy. Also
update documentation of the "state" property and "valid_zones" properties.
Link: https://lkml.kernel.org/r/20210201181347.13262-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: David Hildenbrand <david@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Ilya Dryomov <idryomov@gmail.com> Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Cc: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/base/memory: don't store phys_device in memory blocks
No need to store the value for each and every memory block, as we can
easily query the value at runtime. Reshuffle the members to optimize the
memory layout. Also, let's clarify what the interface once was used for
and why it's legacy nowadays.
"phys_device" was used on s390x in older versions of lsmem[2]/chmem[3],
back when they were still part of s390x-tools. They were later replaced
by the variants in linux-utils. For example, RHEL6 and RHEL7 contain
lsmem/chmem from s390-utils. RHEL8 switched to versions from util-linux
on s390x [4].
"phys_device" was added with sysfs support for memory hotplug in commit 3947be1969a9 ("[PATCH] memory hotplug: sysfs and add/remove functions") in
2005. It always returned 0.
s390x started returning something != 0 on some setups (if sclp.rzm is set
by HW) in 2010 via commit 57b552ba0b2f ("memory hotplug/s390: set
phys_device").
For s390x, it allowed for identifying which memory block devices belong to
the same storage increment (RZM). Only if all memory block devices
comprising a single storage increment were offline, the memory could
actually be removed in the hypervisor.
Since commit e5d709bb5fb7 ("s390/memory hotplug: provide
memory_block_size_bytes() function") in 2013 a memory block device spans
at least one storage increment - which is why the interface isn't really
helpful/used anymore (except by old lsmem/chmem tools).
There were once RFC patches to make use of "phys_device" in ACPI context;
however, the underlying problem could be solved using different interfaces
[1].
Miaohe Lin [Fri, 26 Feb 2021 01:17:21 +0000 (17:17 -0800)]
mm/memory_hotplug: use helper function zone_end_pfn() to get end_pfn
Commit 108bcc96ef70 ("mm: add & use zone_end_pfn() and zone_spans_pfn()")
introduced the helper zone_end_pfn() to calculate the zone end pfn. But
update_pgdat_span() forgot to use it.
Use this helper and rename local variable zone_end_pfn to end_pfn to avoid
a naming conflict with the existing zone_end_pfn().
Link: https://lkml.kernel.org/r/20210127093211.37714-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Let's make "MEMHP_MERGE_RESOURCE" consistent with "MHP_NONE", "mhp_t" and
"mhp_flags". As discussed recently [1], "mhp" is our internal acronym for
memory hotplug now.
mm/memory_hotplug: rename all existing 'memhp' into 'mhp'
This renames all 'memhp' instances to 'mhp' except for memhp_default_state
for being a kernel command line option. This is just a clean up and
should not cause a functional change. Let's make it consistent rater than
mixing the two prefixes. In preparation for more users of the 'mhp'
terminology.
Link: https://lkml.kernel.org/r/1611554093-27316-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Suggested-by: David Hildenbrand <david@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dan Williams [Fri, 26 Feb 2021 01:17:08 +0000 (17:17 -0800)]
mm: fix memory_failure() handling of dax-namespace metadata
Given 'struct dev_pagemap' spans both data pages and metadata pages be
careful to consult the altmap if present to delineate metadata. In fact
the pfn_first() helper already identifies the first valid data pfn, so
export that helper for other code paths via pgmap_pfn_valid().
Other usage of get_dev_pagemap() are not a concern because those are
operating on known data pfns having been looked up by get_user_pages().
I.e. metadata pfns are never user mapped.
Link: https://lkml.kernel.org/r/161058501758.1840162.4239831989762604527.stgit@dwillia2-desk3.amr.corp.intel.com Fixes: 6100e34b2526 ("mm, memory_failure: Teach memory_failure() about dev_pagemap pages") Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reported-by: David Hildenbrand <david@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Qian Cai <cai@lca.pw> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dan Williams [Fri, 26 Feb 2021 01:17:05 +0000 (17:17 -0800)]
mm: teach pfn_to_online_page() about ZONE_DEVICE section collisions
While pfn_to_online_page() is able to determine pfn_valid() at subsection
granularity it is not able to reliably determine if a given pfn is also
online if the section is mixes ZONE_{NORMAL,MOVABLE} with ZONE_DEVICE.
This means that pfn_to_online_page() may return invalid @page objects.
For example with a memory map like:
...succeeds when it should fail. When it succeeds it touches an
uninitialized page and may crash or cause other damage (see
dissolve_free_huge_page()).
While the memory map above is contrived via the memmap=ss!nn kernel
command line option, the collision happens in practice on shipping
platforms. The memory controller resources that decode spans of physical
address space are a limited resource. One technique platform-firmware
uses to conserve those resources is to share a decoder across 2 devices to
keep the address range contiguous. Unfortunately the unit of operation of
a decoder is 64MiB while the Linux section size is 128MiB. This results
in situations where, without subsection hotplug memory mappings with
different lifetimes collide into one object that can only express one
lifetime.
Update move_pfn_range_to_zone() to flag (SECTION_TAINT_ZONE_DEVICE) a
section that mixes ZONE_DEVICE pfns with other online pfns. With
SECTION_TAINT_ZONE_DEVICE to delineate, pfn_to_online_page() can fall back
to a slow-path check for ZONE_DEVICE pfns in an online section. In the
fast path online_section() for a full ZONE_DEVICE section returns false.
Because the collision case is rare, and for simplicity, the
SECTION_TAINT_ZONE_DEVICE flag is never cleared once set.
[dan.j.williams@intel.com: fix CONFIG_ZONE_DEVICE=n build] Link: https://lkml.kernel.org/r/CAPcyv4iX+7LAgAeSqx7Zw-Zd=ZV9gBv8Bo7oTbwCOOqJoZ3+Yg@mail.gmail.com Link: https://lkml.kernel.org/r/161058500675.1840162.7887862152161279354.stgit@dwillia2-desk3.amr.corp.intel.com Fixes: ba72b4c8cf60 ("mm/sparsemem: support sub-section hotplug") Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reported-by: Michal Hocko <mhocko@suse.com> Acked-by: Michal Hocko <mhocko@suse.com> Reported-by: David Hildenbrand <david@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Qian Cai <cai@lca.pw> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dan Williams [Fri, 26 Feb 2021 01:17:01 +0000 (17:17 -0800)]
mm: teach pfn_to_online_page() to consider subsection validity
pfn_to_online_page is primarily used to filter out offline or fully
uninitialized pages. pfn_valid resp. online_section_nr have a coarse
per memory section granularity. If a section shared with a partially
offline memory (e.g. part of ZONE_DEVICE) then pfn_to_online_page
would lead to a false positive on some pfns. Fix this by adding
pfn_section_valid check which is subsection aware.
[mhocko@kernel.org: changelog rewrite]
Link: https://lkml.kernel.org/r/161058500148.1840162.4365921007820501696.stgit@dwillia2-desk3.amr.corp.intel.com Fixes: b13bc35193d9 ("mm/hotplug: invalid PFNs from pfn_to_online_page()") Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reported-by: David Hildenbrand <david@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Qian Cai <cai@lca.pw> Cc: Oscar Salvador <osalvador@suse.de> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dan Williams [Fri, 26 Feb 2021 01:16:57 +0000 (17:16 -0800)]
mm: move pfn_to_online_page() out of line
Patch series "mm: Fix pfn_to_online_page() with respect to ZONE_DEVICE", v4.
A pfn-walker that uses pfn_to_online_page() may inadvertently translate a
pfn as online and in the page allocator, when it is offline managed by a
ZONE_DEVICE mapping (details in Patch 3: ("mm: Teach pfn_to_online_page()
about ZONE_DEVICE section collisions")).
The 2 proposals under consideration are teach pfn_to_online_page() to be
precise in the presence of mixed-zone sections, or teach the memory-add
code to drop the System RAM associated with ZONE_DEVICE collisions. In
order to not regress memory capacity by a few 10s to 100s of MiB the
approach taken in this set is to add precision to pfn_to_online_page().
In the course of validating pfn_to_online_page() a couple other fixes
fell out:
1/ soft_offline_page() fails to drop the reference taken in the
madvise(..., MADV_SOFT_OFFLINE) case.
2/ memory_failure() uses get_dev_pagemap() to lookup ZONE_DEVICE pages,
however that mapping may contain data pages and metadata raw pfns.
Introduce pgmap_pfn_valid() to delineate the 2 types and fail the
handling of raw metadata pfns.
This patch (of 4);
pfn_to_online_page() is already too large to be a macro or an inline
function. In anticipation of further logic changes / growth, move it out
of line.
Jiang Biao [Fri, 26 Feb 2021 01:16:54 +0000 (17:16 -0800)]
mm/vmstat.c: erase latency in vmstat_shepherd
Many 100us+ latencies have been deteceted in vmstat_shepherd() on CPX
platform which has 208 logic cpus. And vmstat_shepherd is queued every
second, which could make the case worse.
Add schedule point in vmstat_shepherd() to erase the latency.
Link: https://lkml.kernel.org/r/20210111035526.1511-1-benbjiang@tencent.com Signed-off-by: Jiang Biao <benbjiang@tencent.com> Reported-by: Bin Lai <robinlai@tencent.com> Cc: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Fri, 26 Feb 2021 01:16:51 +0000 (17:16 -0800)]
mm: vmstat: add some comments on internal storage of byte items
Byte-accounted items are used for slab object accounting at the cgroup
level, because the objects in a slab page can belong to different cgroups.
At the global level these items always change in multiples of whole slab
pages. The vmstat code exploits this and stores these items as pages
internally, which allows for more compact per-cpu data.
This optimization isn't self-evident from the asserts and the division in
the stat update functions. Provide the reader with some context.
Johannes Weiner [Fri, 26 Feb 2021 01:16:47 +0000 (17:16 -0800)]
mm: vmstat: fix NOHZ wakeups for node stat changes
On NOHZ, the periodic vmstat flushers on each CPU can go to sleep and
won't wake up until stat changes are detected in the per-cpu deltas of the
zone vmstat counters.
In commit 75ef71840539 ("mm, vmstat: add infrastructure for per-node
vmstats") per-node counters were introduced, and subsequently most stats
were moved from the zone to the node level. However, the node counters
weren't added to the NOHZ wakeup detection.
In theory this can cause per-cpu errors to remain in the user-reported
stats indefinitely. In practice this only affects a handful of sub
counters (file_mapped, dirty and writeback e.g.) because other page state
changes at the node level likely involve a change at the zone level as
well (alloc and free, lru ops). Also, nobody has complained.
Fix it up for completeness: wake up vmstat refreshing on node changes.
Also remove the BUILD_BUG_ONs that assert counter size; we haven't relied
on it since we added sizeof() to the range calculation in commit 13c9aaf7fa01 ("mm/vmstat.c: fix NUMA statistics updates").
mm/page_alloc: count CMA pages per zone and print them in /proc/zoneinfo
Let's count the number of CMA pages per zone and print them in
/proc/zoneinfo.
Having access to the total number of CMA pages per zone is helpful for
debugging purposes to know where exactly the CMA pages ended up, and to
figure out how many pages of a zone might behave differently, even after
some of these pages might already have been allocated.
As one example, CMA pages part of a kernel zone cannot be used for
ordinary kernel allocations but instead behave more like ZONE_MOVABLE.
For now, we are only able to get the global nr+free cma pages from
/proc/meminfo and the free cma pages per zone from /proc/zoneinfo.
Example after this patch when booting a 6 GiB QEMU VM with
"hugetlb_cma=2G":
# cat /proc/zoneinfo | grep cma
cma 0
nr_free_cma 0
cma 0
nr_free_cma 0
cma 524288
nr_free_cma 493016
cma 0
cma 0
# cat /proc/meminfo | grep Cma
CmaTotal: 2097152 kB
CmaFree: 1972064 kB
Note: We print even without CONFIG_CMA, just like "nr_free_cma"; this way,
one can be sure when spotting "cma 0", that there are definetly no
CMA pages located in a zone.
mm/cma: expose all pages to the buddy if activation of an area fails
Right now, if activation fails, we might already have exposed some pages
to the buddy for CMA use (although they will never get actually used by
CMA), and some pages won't be exposed to the buddy at all.
Let's check for "single zone" early and on error, don't expose any pages
for CMA use - instead, expose them to the buddy available for any use.
Simply call free_reserved_page() on every single page - easier than going
via free_reserved_area(), converting back and forth between pfns and virt
addresses.
In addition, make sure to fixup totalcma_pages properly.
Example: 6 GiB QEMU VM with "... hugetlb_cma=2G movablecore=20% ...":
[ 0.006891] hugetlb_cma: reserve 2048 MiB, up to 2048 MiB per node
[ 0.006893] cma: Reserved 2048 MiB at 0x0000000100000000
[ 0.006893] hugetlb_cma: reserved 2048 MiB on node 0
...
[ 0.175433] cma: CMA area hugetlb0 could not be activated
Note: cma_init_reserved_mem() makes sure that we always cover full
pageblocks / MAX_ORDER - 1 pages.
Link: https://lkml.kernel.org/r/20210127101813.6370-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Roman Gushchin [Fri, 26 Feb 2021 01:16:33 +0000 (17:16 -0800)]
mm: cma: allocate cma areas bottom-up
Currently cma areas without a fixed base are allocated close to the end of
the node. This placement is sub-optimal because of compaction: it brings
pages into the cma area. In particular, it can bring in hot executable
pages, even if there is a plenty of free memory on the machine. This
results in cma allocation failures.
Instead let's place cma areas close to the beginning of a node. In this
case the compaction will help to free cma areas, resulting in better cma
allocation success rates.
If there is enough memory let's try to allocate bottom-up starting with
4GB to exclude any possible interference with DMA32. On smaller machines
or in a case of a failure, stick with the old behavior.
16GB vm, 2GB cma area:
With this patch:
[ 0.000000] Command line: root=/dev/vda3 rootflags=subvol=/root systemd.unified_cgroup_hierarchy=1 enforcing=0 console=ttyS0,115200 hugetlb_cma=2G
[ 0.002928] hugetlb_cma: reserve 2048 MiB, up to 2048 MiB per node
[ 0.002930] cma: Reserved 2048 MiB at 0x0000000100000000
[ 0.002931] hugetlb_cma: reserved 2048 MiB on node 0
Without this patch:
[ 0.000000] Command line: root=/dev/vda3 rootflags=subvol=/root systemd.unified_cgroup_hierarchy=1 enforcing=0 console=ttyS0,115200 hugetlb_cma=2G
[ 0.002930] hugetlb_cma: reserve 2048 MiB, up to 2048 MiB per node
[ 0.002933] cma: Reserved 2048 MiB at 0x00000003c0000000
[ 0.002934] hugetlb_cma: reserved 2048 MiB on node 0
v2:
- switched to memblock_set_bottom_up(true), by Mike
- start with 4GB, by Mike
Link: https://lkml.kernel.org/r/20201217201214.3414100-1-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Cc: Wonhyuk Yang <vvghjk1234@gmail.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Rik van Riel <riel@surriel.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rik van Riel [Fri, 26 Feb 2021 01:16:29 +0000 (17:16 -0800)]
mm,shmem,thp: limit shmem THP allocations to requested zones
Hugh pointed out that the gma500 driver uses shmem pages, but needs to
limit them to the DMA32 zone. Ensure the allocations resulting from the
gfp_mask returned by limit_gfp_mask use the zone flags that were
originally passed to shmem_getpage_gfp.
Link: https://lkml.kernel.org/r/20210224121016.1314ed6d@imladris.surriel.com Signed-off-by: Rik van Riel <riel@surriel.com> Suggested-by: Hugh Dickins <hughd@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xu Yu <xuyu@linux.alibaba.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rik van Riel [Fri, 26 Feb 2021 01:16:25 +0000 (17:16 -0800)]
mm,thp,shmem: make khugepaged obey tmpfs mount flags
Currently if thp enabled=[madvise], mounting a tmpfs filesystem with
huge=always and mmapping files from that tmpfs does not result in
khugepaged collapsing those mappings, despite the mount flag indicating
that it should.
Fix that by breaking up the blocks of tests in hugepage_vma_check a little
bit, and testing things in the correct order.
Link: https://lkml.kernel.org/r/20201124194925.623931-4-riel@surriel.com Fixes: c2231020ea7b ("mm: thp: register mm for khugepaged when merging vma for shmem") Signed-off-by: Rik van Riel <riel@surriel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xu Yu <xuyu@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rik van Riel [Fri, 26 Feb 2021 01:16:22 +0000 (17:16 -0800)]
mm,thp,shm: limit gfp mask to no more than specified
Matthew Wilcox pointed out that the i915 driver opportunistically
allocates tmpfs memory, but will happily reclaim some of its pool if no
memory is available.
Make sure the gfp mask used to opportunistically allocate a THP is always
at least as restrictive as the original gfp mask.
Link: https://lkml.kernel.org/r/20201124194925.623931-3-riel@surriel.com Signed-off-by: Rik van Riel <riel@surriel.com> Suggested-by: Matthew Wilcox <willy@infradead.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xu Yu <xuyu@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rik van Riel [Fri, 26 Feb 2021 01:16:18 +0000 (17:16 -0800)]
mm,thp,shmem: limit shmem THP alloc gfp_mask
Patch series "mm,thp,shm: limit shmem THP alloc gfp_mask", v6.
The allocation flags of anonymous transparent huge pages can be controlled
through the files in /sys/kernel/mm/transparent_hugepage/defrag, which can
help the system from getting bogged down in the page reclaim and
compaction code when many THPs are getting allocated simultaneously.
However, the gfp_mask for shmem THP allocations were not limited by those
configuration settings, and some workloads ended up with all CPUs stuck on
the LRU lock in the page reclaim code, trying to allocate dozens of THPs
simultaneously.
This patch applies the same configurated limitation of THPs to shmem
hugepage allocations, to prevent that from happening.
This way a THP defrag setting of "never" or "defer+madvise" will result in
quick allocation failures without direct reclaim when no 2MB free pages
are available.
With this patch applied, THP allocations for tmpfs will be a little more
aggressive than today for files mmapped with MADV_HUGEPAGE, and a little
less aggressive for files that are not mmapped or mapped without that
flag.
This patch (of 4):
The allocation flags of anonymous transparent huge pages can be controlled
through the files in /sys/kernel/mm/transparent_hugepage/defrag, which can
help the system from getting bogged down in the page reclaim and
compaction code when many THPs are getting allocated simultaneously.
However, the gfp_mask for shmem THP allocations were not limited by those
configuration settings, and some workloads ended up with all CPUs stuck on
the LRU lock in the page reclaim code, trying to allocate dozens of THPs
simultaneously.
This patch applies the same configurated limitation of THPs to shmem
hugepage allocations, to prevent that from happening.
Controlling the gfp_mask of THP allocations through the knobs in sysfs
allows users to determine the balance between how aggressively the system
tries to allocate THPs at fault time, and how much the application may end
up stalling attempting those allocations.
This way a THP defrag setting of "never" or "defer+madvise" will result in
quick allocation failures without direct reclaim when no 2MB free pages
are available.
With this patch applied, THP allocations for tmpfs will be a little more
aggressive than today for files mmapped with MADV_HUGEPAGE, and a little
less aggressive for files that are not mmapped or mapped without that
flag.
Link: https://lkml.kernel.org/r/20201124194925.623931-1-riel@surriel.com Link: https://lkml.kernel.org/r/20201124194925.623931-2-riel@surriel.com Signed-off-by: Rik van Riel <riel@surriel.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Xu Yu <xuyu@linux.alibaba.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
pagevec_lookup_entries() is now just a wrapper around find_get_entries()
so remove it and convert all its callers.
Link: https://lkml.kernel.org/r/20201112212641.27837-15-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
All callers of find_get_entries() use a pvec, so pass it directly instead
of manipulating it in the caller.
Link: https://lkml.kernel.org/r/20201112212641.27837-14-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: remove nr_entries parameter from pagevec_lookup_entries
All callers want to fetch the full size of the pvec.
Link: https://lkml.kernel.org/r/20201112212641.27837-13-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: add an 'end' parameter to pagevec_lookup_entries
Simplifies the callers and uses the existing functionality in
find_get_entries(). We can also drop the final argument of
truncate_exceptional_pvec_entries() and simplify the logic in that
function.
Link: https://lkml.kernel.org/r/20201112212641.27837-12-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This simplifies the callers and leads to a more efficient implementation
since the XArray has this functionality already.
Link: https://lkml.kernel.org/r/20201112212641.27837-11-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We have three functions (shmem_undo_range(), truncate_inode_pages_range()
and invalidate_mapping_pages()) which want exactly this function, so add
it to filemap.c. Before this patch, shmem_undo_range() would split any
compound page which overlaps either end of the range being punched in both
the first and second loops through the address space. After this patch,
that functionality is left for the second loop, which is arguably more
appropriate since the first loop is supposed to run through all the pages
quickly, and splitting a page can sleep.
[willy@infradead.org: add assertion] Link: https://lkml.kernel.org/r/20201124041507.28996-3-willy@infradead.org Link: https://lkml.kernel.org/r/20201112212641.27837-10-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Enhance mapping_seek_hole_data() to handle partially uptodate pages and
convert the iomap seek code to call it.
Link: https://lkml.kernel.org/r/20201112212641.27837-9-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: William Kucharski <william.kucharski@oracle.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rewrite shmem_seek_hole_data() and move it to filemap.c.
[willy@infradead.org: don't put an xa_is_value() page] Link: https://lkml.kernel.org/r/20201124041507.28996-4-willy@infradead.org Link: https://lkml.kernel.org/r/20201112212641.27837-8-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a lot of common code in find_get_entries(),
find_get_pages_range() and find_get_pages_range_tag(). Factor out
find_get_entry() which simplifies all three functions.
[willy@infradead.org: remove VM_BUG_ON_PAGE()] Link: https://lkml.kernel.org/r/20201124041507.28996-2-willy@infradead.orgLink: Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/filemap: rename find_get_entry to mapping_get_entry
find_get_entry doesn't "find" anything. It returns the entry at a
particular index.
Link: https://lkml.kernel.org/r/20201112212641.27837-6-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: William Kucharski <william.kucharski@oracle.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The functionality of find_lock_entry() and find_get_entry() can be
provided by pagecache_get_page(), which lets us delete find_lock_entry()
and make find_get_entry() static.
Link: https://lkml.kernel.org/r/20201112212641.27837-5-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: William Kucharski <william.kucharski@oracle.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There's no need to get a reference to the page, just load the entry and
see if it's a shadow entry.
Link: https://lkml.kernel.org/r/20201112212641.27837-4-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: William Kucharski <william.kucharski@oracle.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/shmem: use pagevec_lookup in shmem_unlock_mapping
The comment shows that the reason for using find_get_entries() is now
stale; find_get_pages() will not return 0 if it hits a consecutive run of
swap entries, and I don't believe it has since 2011. pagevec_lookup() is
a simpler function to use than find_get_pages(), so use it instead.
Link: https://lkml.kernel.org/r/20201112212641.27837-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: make pagecache tagged lookups return only head pages
Patch series "Overhaul multi-page lookups for THP", v4.
This THP prep patchset changes several page cache iteration APIs to only
return head pages.
- It's only possible to tag head pages in the page cache, so only
return head pages, not all their subpages.
- Factor a lot of common code out of the various batch lookup routines
- Add mapping_seek_hole_data()
- Unify find_get_entries() and pagevec_lookup_entries()
- Make find_get_entries only return head pages, like find_get_entry().
These are only loosely connected, but they seem to make sense together as
a series.
This patch (of 14):
Pagecache tags are used for dirty page writeback. Since dirtiness is
tracked on a per-THP basis, we only want to return the head page rather
than each subpage of a tagged page. All the filesystems which use huge
pages today are in-memory, so there are no tagged huge pages today.
Link: https://lkml.kernel.org/r/20201112212641.27837-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Yang Shi <yang.shi@linux.alibaba.com> Cc: Dave Chinner <dchinner@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds [Thu, 25 Feb 2021 18:17:31 +0000 (10:17 -0800)]
Merge tag 'kbuild-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
- Fix false-positive build warnings for ARCH=ia64 builds
- Optimize dictionary size for module compression with xz
- Check the compiler and linker versions in Kconfig
- Fix misuse of extra-y
- Support DWARF v5 debug info
- Clamp SUBLEVEL to 255 because stable releases 4.4.x and 4.9.x
exceeded the limit
- Add generic syscall{tbl,hdr}.sh for cleanups across arches
- Minor cleanups of genksyms
- Minor cleanups of Kconfig
* tag 'kbuild-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (38 commits)
initramfs: Remove redundant dependency of RD_ZSTD on BLK_DEV_INITRD
kbuild: remove deprecated 'always' and 'hostprogs-y/m'
kbuild: parse C= and M= before changing the working directory
kbuild: reuse this-makefile to define abs_srctree
kconfig: unify rule of config, menuconfig, nconfig, gconfig, xconfig
kconfig: omit --oldaskconfig option for 'make config'
kconfig: fix 'invalid option' for help option
kconfig: remove dead code in conf_askvalue()
kconfig: clean up nested if-conditionals in check_conf()
kconfig: Remove duplicate call to sym_get_string_value()
Makefile: Remove # characters from compiler string
Makefile: reuse CC_VERSION_TEXT
kbuild: check the minimum linker version in Kconfig
kbuild: remove ld-version macro
scripts: add generic syscallhdr.sh
scripts: add generic syscalltbl.sh
arch: syscalls: remove $(srctree)/ prefix from syscall tables
arch: syscalls: add missing FORCE and fix 'targets' to make if_changed work
gen_compile_commands: prune some directories
kbuild: simplify access to the kernel's version
...
Linus Torvalds [Thu, 25 Feb 2021 18:06:55 +0000 (10:06 -0800)]
Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 updates from Ted Ts'o:
"Miscellaneous ext4 cleanups and bug fixes. Pretty boring this cycle..."
* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: add .kunitconfig fragment to enable ext4-specific tests
ext: EXT4_KUNIT_TESTS should depend on EXT4_FS instead of selecting it
ext4: reset retry counter when ext4_alloc_file_blocks() makes progress
ext4: fix potential htree index checksum corruption
ext4: factor out htree rep invariant check
ext4: Change list_for_each* to list_for_each_entry*
ext4: don't try to processed freed blocks until mballoc is initialized
ext4: use DEFINE_MUTEX() for mutex lock
projects / mirror_ubuntu-kernels.git / log