Pull aio updates from Al Viro:
"Majority of AIO stuff this cycle. aio-fsync and aio-poll, mostly.
The only thing I'm holding back for a day or so is Adam's aio ioprio -
his last-minute fixup is trivial (missing stub in !CONFIG_BLOCK case),
but let it sit in -next for decency sake..."
* 'work.aio-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits)
aio: sanitize the limit checking in io_submit(2)
aio: fold do_io_submit() into callers
aio: shift copyin of iocb into io_submit_one()
aio_read_events_ring(): make a bit more readable
aio: all callers of aio_{read,write,fsync,poll} treat 0 and -EIOCBQUEUED the same way
aio: take list removal to (some) callers of aio_complete()
aio: add missing break for the IOCB_CMD_FDSYNC case
random: convert to ->poll_mask
timerfd: convert to ->poll_mask
eventfd: switch to ->poll_mask
pipe: convert to ->poll_mask
crypto: af_alg: convert to ->poll_mask
net/rxrpc: convert to ->poll_mask
net/iucv: convert to ->poll_mask
net/phonet: convert to ->poll_mask
net/nfc: convert to ->poll_mask
net/caif: convert to ->poll_mask
net/bluetooth: convert to ->poll_mask
net/sctp: convert to ->poll_mask
net/tipc: convert to ->poll_mask
...
including:
- Extensive RST conversions and organizational work in the
memory-management docs thanks to Mike Rapoport.
- An update of Documentation/features from Andrea Parri and a script to
keep it updated.
- Various LICENSES updates from Thomas, along with a script to check SPDX
tags.
- Work to fix dangling references to documentation files; this involved a
fair number of one-liner comment changes outside of Documentation/
...and the usual list of documentation improvements, typo fixes, etc.
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Merge tag 'docs-4.18' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
"There's been a fair amount of work in the docs tree this time around,
including:
- Extensive RST conversions and organizational work in the
memory-management docs thanks to Mike Rapoport.
- An update of Documentation/features from Andrea Parri and a script
to keep it updated.
- Various LICENSES updates from Thomas, along with a script to check
SPDX tags.
- Work to fix dangling references to documentation files; this
involved a fair number of one-liner comment changes outside of
Documentation/
... and the usual list of documentation improvements, typo fixes, etc"
* tag 'docs-4.18' of git://git.lwn.net/linux: (103 commits)
Documentation: document hung_task_panic kernel parameter
docs/admin-guide/mm: add high level concepts overview
docs/vm: move ksm and transhuge from "user" to "internals" section.
docs: Use the kerneldoc comments for memalloc_no*()
doc: document scope NOFS, NOIO APIs
docs: update kernel versions and dates in tables
docs/vm: transhuge: split userspace bits to admin-guide/mm/transhuge
docs/vm: transhuge: minor updates
docs/vm: transhuge: change sections order
Documentation: arm: clean up Marvell Berlin family info
Documentation: gpio: driver: Fix a typo and some odd grammar
docs: ranoops.rst: fix location of ramoops.txt
scripts/documentation-file-ref-check: rewrite it in perl with auto-fix mode
docs: uio-howto.rst: use a code block to solve a warning
mm, THP, doc: Add document for thp_swpout/thp_swpout_fallback
w1: w1_io.c: fix a kernel-doc warning
Documentation/process/posting: wrap text at 80 cols
docs: admin-guide: add cgroup-v2 documentation
Revert "Documentation/features/vm: Remove arch support status file for 'pte_special'"
Documentation: refcount-vs-atomic: Update reference to LKMM doc.
...
- replaceme the force_dma flag with a dma_configure bus method.
(Nipun Gupta, although one patch is іncorrectly attributed to me
due to a git rebase bug)
- use GFP_DMA32 more agressively in dma-direct. (Takashi Iwai)
- remove PCI_DMA_BUS_IS_PHYS and rely on the dma-mapping API to do the
right thing for bounce buffering.
- move dma-debug initialization to common code, and apply a few cleanups
to the dma-debug code.
- cleanup the Kconfig mess around swiotlb selection
- swiotlb comment fixup (Yisheng Xie)
- a trivial swiotlb fix. (Dan Carpenter)
- support swiotlb on RISC-V. (based on a patch from Palmer Dabbelt)
- add a new generic dma-noncoherent dma_map_ops implementation and use
it for arc, c6x and nds32.
- improve scatterlist validity checking in dma-debug. (Robin Murphy)
- add a struct device quirk to limit the dma-mask to 32-bit due to
bridge/system issues, and switch x86 to use it instead of a local
hack for VIA bridges.
- handle devices without a dma_mask more gracefully in the dma-direct
code.
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Merge tag 'dma-mapping-4.18' of git://git.infradead.org/users/hch/dma-mapping
Pull dma-mapping updates from Christoph Hellwig:
- replace the force_dma flag with a dma_configure bus method. (Nipun
Gupta, although one patch is іncorrectly attributed to me due to a
git rebase bug)
- use GFP_DMA32 more agressively in dma-direct. (Takashi Iwai)
- remove PCI_DMA_BUS_IS_PHYS and rely on the dma-mapping API to do the
right thing for bounce buffering.
- move dma-debug initialization to common code, and apply a few
cleanups to the dma-debug code.
- cleanup the Kconfig mess around swiotlb selection
- swiotlb comment fixup (Yisheng Xie)
- a trivial swiotlb fix. (Dan Carpenter)
- support swiotlb on RISC-V. (based on a patch from Palmer Dabbelt)
- add a new generic dma-noncoherent dma_map_ops implementation and use
it for arc, c6x and nds32.
- improve scatterlist validity checking in dma-debug. (Robin Murphy)
- add a struct device quirk to limit the dma-mask to 32-bit due to
bridge/system issues, and switch x86 to use it instead of a local
hack for VIA bridges.
- handle devices without a dma_mask more gracefully in the dma-direct
code.
* tag 'dma-mapping-4.18' of git://git.infradead.org/users/hch/dma-mapping: (48 commits)
dma-direct: don't crash on device without dma_mask
nds32: use generic dma_noncoherent_ops
nds32: implement the unmap_sg DMA operation
nds32: consolidate DMA cache maintainance routines
x86/pci-dma: switch the VIA 32-bit DMA quirk to use the struct device flag
x86/pci-dma: remove the explicit nodac and allowdac option
x86/pci-dma: remove the experimental forcesac boot option
Documentation/x86: remove a stray reference to pci-nommu.c
core, dma-direct: add a flag 32-bit dma limits
dma-mapping: remove unused gfp_t parameter to arch_dma_alloc_attrs
dma-debug: check scatterlist segments
c6x: use generic dma_noncoherent_ops
arc: use generic dma_noncoherent_ops
arc: fix arc_dma_{map,unmap}_page
arc: fix arc_dma_sync_sg_for_{cpu,device}
arc: simplify arc_dma_sync_single_for_{cpu,device}
dma-mapping: provide a generic dma-noncoherent implementation
dma-mapping: simplify Kconfig dependencies
riscv: add swiotlb support
riscv: only enable ZONE_DMA32 for 64-bit
...
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Merge tag 'for-4.18/block-20180603' of git://git.kernel.dk/linux-block
Pull block updates from Jens Axboe:
- clean up how we pass around gfp_t and
blk_mq_req_flags_t (Christoph)
- prepare us to defer scheduler attach (Christoph)
- clean up drivers handling of bounce buffers (Christoph)
- fix timeout handling corner cases (Christoph/Bart/Keith)
- bcache fixes (Coly)
- prep work for bcachefs and some block layer optimizations (Kent).
- convert users of bio_sets to using embedded structs (Kent).
- fixes for the BFQ io scheduler (Paolo/Davide/Filippo)
- lightnvm fixes and improvements (Matias, with contributions from Hans
and Javier)
- adding discard throttling to blk-wbt (me)
- sbitmap blk-mq-tag handling (me/Omar/Ming).
- remove the sparc jsflash block driver, acked by DaveM.
- Kyber scheduler improvement from Jianchao, making it more friendly
wrt merging.
- conversion of symbolic proc permissions to octal, from Joe Perches.
Previously the block parts were a mix of both.
- nbd fixes (Josef and Kevin Vigor)
- unify how we handle the various kinds of timestamps that the block
core and utility code uses (Omar)
- three NVMe pull requests from Keith and Christoph, bringing AEN to
feature completeness, file backed namespaces, cq/sq lock split, and
various fixes
- various little fixes and improvements all over the map
* tag 'for-4.18/block-20180603' of git://git.kernel.dk/linux-block: (196 commits)
blk-mq: update nr_requests when switching to 'none' scheduler
block: don't use blocking queue entered for recursive bio submits
dm-crypt: fix warning in shutdown path
lightnvm: pblk: take bitmap alloc. out of critical section
lightnvm: pblk: kick writer on new flush points
lightnvm: pblk: only try to recover lines with written smeta
lightnvm: pblk: remove unnecessary bio_get/put
lightnvm: pblk: add possibility to set write buffer size manually
lightnvm: fix partial read error path
lightnvm: proper error handling for pblk_bio_add_pages
lightnvm: pblk: fix smeta write error path
lightnvm: pblk: garbage collect lines with failed writes
lightnvm: pblk: rework write error recovery path
lightnvm: pblk: remove dead function
lightnvm: pass flag on graceful teardown to targets
lightnvm: pblk: check for chunk size before allocating it
lightnvm: pblk: remove unnecessary argument
lightnvm: pblk: remove unnecessary indirection
lightnvm: pblk: return NVM_ error on failed submission
lightnvm: pblk: warn in case of corrupted write buffer
...
George Boole would have noticed a slight error in 4.16 commit
69d763fc6d ("mm: pin address_space before dereferencing it while
isolating an LRU page"). Fix it, to match both the comment above it,
and the original behaviour.
Although anonymous pages are not marked PageDirty at first, we have an
old habit of calling SetPageDirty when a page is removed from swap
cache: so there's a category of ex-swap pages that are easily
migratable, but were inadvertently excluded from compaction's async
migration in 4.16.
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1805302014001.12558@eggly.anvils
Fixes: 69d763fc6d ("mm: pin address_space before dereferencing it while isolating an LRU page")
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Reported-by: Ivan Kalvachev <ikalvachev@gmail.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Swapping load on huge=always tmpfs (with khugepaged tuned up to be very
eager, but I'm not sure that is relevant) soon hung uninterruptibly,
waiting for page lock in shmem_getpage_gfp()'s find_lock_entry(), most
often when "cp -a" was trying to write to a smallish file. Debug showed
that the page in question was not locked, and page->mapping NULL by now,
but page->index consistent with having been in a huge page before.
Reproduced in minutes on a 4.15 kernel, even with 4.17's 605ca5ede7
("mm/huge_memory.c: reorder operations in __split_huge_page_tail()") added
in; but took hours to reproduce on a 4.17 kernel (no idea why).
The culprit proved to be the __ClearPageDirty() on tails beyond i_size in
__split_huge_page(): the non-atomic __bitoperation may have been safe when
4.8's baa355fd33 ("thp: file pages support for split_huge_page()")
introduced it, but liable to erase PageWaiters after 4.10's 6290602709
("mm: add PageWaiters indicating tasks are waiting for a page bit").
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1805291841070.3197@eggly.anvils
Fixes: 6290602709 ("mm: add PageWaiters indicating tasks are waiting for a page bit")
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Nicholas Piggin <npiggin@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>
These abstract out calls to the poll method in preparation for changes
in how we poll.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Using module_init() is wrong. E.g. ACPI adds and onlines memory before
our memory notifier gets registered.
This makes sure that ACPI memory detected during boot up will not result
in a kernel crash.
Easily reproducible with QEMU, just specify a DIMM when starting up.
Link: http://lkml.kernel.org/r/20180522100756.18478-3-david@redhat.com
Fixes: 786a895991 ("kasan: disable memory hotplug")
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We have to free memory again when we cancel onlining, otherwise a later
onlining attempt will fail.
Link: http://lkml.kernel.org/r/20180522100756.18478-2-david@redhat.com
Fixes: fa69b5989b ("mm/kasan: add support for memory hotplug")
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The case of a new numa node got missed in avoiding using the node info
from page_struct during hotplug. In this path we have a call to
register_mem_sect_under_node (which allows us to specify it is hotplug
so don't change the node), via link_mem_sections which unfortunately
does not.
Fix is to pass check_nid through link_mem_sections as well and disable
it in the new numa node path.
Note the bug only 'sometimes' manifests depending on what happens to be
in the struct page structures - there are lots of them and it only needs
to match one of them.
The result of the bug is that (with a new memory only node) we never
successfully call register_mem_sect_under_node so don't get the memory
associated with the node in sysfs and meminfo for the node doesn't
report it.
It came up whilst testing some arm64 hotplug patches, but appears to be
universal. Whilst I'm triggering it by removing then reinserting memory
to a node with no other elements (thus making the node disappear then
appear again), it appears it would happen on hotplugging memory where
there was none before and it doesn't seem to be related the arm64
patches.
These patches call __add_pages (where most of the issue was fixed by
Pavel's patch). If there is a node at the time of the __add_pages call
then all is well as it calls register_mem_sect_under_node from there
with check_nid set to false. Without a node that function returns
having not done the sysfs related stuff as there is no node to use.
This is expected but it is the resulting path that fails...
Exact path to the problem is as follows:
mm/memory_hotplug.c: add_memory_resource()
The node is not online so we enter the 'if (new_node)' twice, on the
second such block there is a call to link_mem_sections which calls
into
drivers/node.c: link_mem_sections() which calls
drivers/node.c: register_mem_sect_under_node() which calls
get_nid_for_pfn and keeps trying until the output of that matches
the expected node (passed all the way down from
add_memory_resource)
It is effectively the same fix as the one referred to in the fixes tag
just in the code path for a new node where the comments point out we
have to rerun the link creation because it will have failed in
register_new_memory (as there was no node at the time). (actually that
comment is wrong now as we don't have register_new_memory any more it
got renamed to hotplug_memory_register in Pavel's patch).
Link: http://lkml.kernel.org/r/20180504085311.1240-1-Jonathan.Cameron@huawei.com
Fixes: fc44f7f923 ("mm/memory_hotplug: don't read nid from struct page during hotplug")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oscar has reported:
: Due to an unfortunate setting with movablecore, memblocks containing bootmem
: memory (pages marked by get_page_bootmem()) ended up marked in zone_movable.
: So while trying to remove that memory, the system failed in do_migrate_range
: and __offline_pages never returned.
:
: This can be reproduced by running
: qemu-system-x86_64 -m 6G,slots=8,maxmem=8G -numa node,mem=4096M -numa node,mem=2048M
: and movablecore=4G kernel command line
:
: linux kernel: BIOS-provided physical RAM map:
: linux kernel: BIOS-e820: [mem 0x0000000000000000-0x000000000009fbff] usable
: linux kernel: BIOS-e820: [mem 0x000000000009fc00-0x000000000009ffff] reserved
: linux kernel: BIOS-e820: [mem 0x00000000000f0000-0x00000000000fffff] reserved
: linux kernel: BIOS-e820: [mem 0x0000000000100000-0x00000000bffdffff] usable
: linux kernel: BIOS-e820: [mem 0x00000000bffe0000-0x00000000bfffffff] reserved
: linux kernel: BIOS-e820: [mem 0x00000000feffc000-0x00000000feffffff] reserved
: linux kernel: BIOS-e820: [mem 0x00000000fffc0000-0x00000000ffffffff] reserved
: linux kernel: BIOS-e820: [mem 0x0000000100000000-0x00000001bfffffff] usable
: linux kernel: NX (Execute Disable) protection: active
: linux kernel: SMBIOS 2.8 present.
: linux kernel: DMI: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org
: linux kernel: Hypervisor detected: KVM
: linux kernel: e820: update [mem 0x00000000-0x00000fff] usable ==> reserved
: linux kernel: e820: remove [mem 0x000a0000-0x000fffff] usable
: linux kernel: last_pfn = 0x1c0000 max_arch_pfn = 0x400000000
:
: linux kernel: SRAT: PXM 0 -> APIC 0x00 -> Node 0
: linux kernel: SRAT: PXM 1 -> APIC 0x01 -> Node 1
: linux kernel: ACPI: SRAT: Node 0 PXM 0 [mem 0x00000000-0x0009ffff]
: linux kernel: ACPI: SRAT: Node 0 PXM 0 [mem 0x00100000-0xbfffffff]
: linux kernel: ACPI: SRAT: Node 0 PXM 0 [mem 0x100000000-0x13fffffff]
: linux kernel: ACPI: SRAT: Node 1 PXM 1 [mem 0x140000000-0x1bfffffff]
: linux kernel: ACPI: SRAT: Node 0 PXM 0 [mem 0x1c0000000-0x43fffffff] hotplug
: linux kernel: NUMA: Node 0 [mem 0x00000000-0x0009ffff] + [mem 0x00100000-0xbfffffff] -> [mem 0x0
: linux kernel: NUMA: Node 0 [mem 0x00000000-0xbfffffff] + [mem 0x100000000-0x13fffffff] -> [mem 0
: linux kernel: NODE_DATA(0) allocated [mem 0x13ffd6000-0x13fffffff]
: linux kernel: NODE_DATA(1) allocated [mem 0x1bffd3000-0x1bfffcfff]
:
: zoneinfo shows that the zone movable is placed into both numa nodes:
: Node 0, zone Movable
: pages free 160140
: min 1823
: low 2278
: high 2733
: spanned 262144
: present 262144
: managed 245670
: Node 1, zone Movable
: pages free 448427
: min 3827
: low 4783
: high 5739
: spanned 524288
: present 524288
: managed 515766
Note how only Node 0 has a hutplugable memory region which would rule it
out from the early memblock allocations (most likely memmap). Node1
will surely contain memmaps on the same node and those would prevent
offlining to succeed. So this is arguably a configuration issue.
Although one could argue that we should be more clever and rule early
allocations from the zone movable. This would be correct but probably
not worth the effort considering what a hack movablecore is.
Anyway, We could do better for those cases though. We rely on
start_isolate_page_range resp. has_unmovable_pages to do their job.
The first one isolates the whole range to be offlined so that we do not
allocate from it anymore and the later makes sure we are not stumbling
over non-migrateable pages.
has_unmovable_pages is overly optimistic, however. It doesn't check all
the pages if we are withing zone_movable because we rely that those
pages will be always migrateable. As it turns out we are still not
perfect there. While bootmem pages in zonemovable sound like a clear
bug which should be fixed let's remove the optimization for now and warn
if we encounter unmovable pages in zone_movable in the meantime. That
should help for now at least.
Btw. this wasn't a real problem until commit 72b39cfc4d ("mm,
memory_hotplug: do not fail offlining too early") because we used to
have a small number of retries and then failed. This turned out to be
too fragile though.
Link: http://lkml.kernel.org/r/20180523125555.30039-2-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Oscar Salvador <osalvador@techadventures.net>
Tested-by: Oscar Salvador <osalvador@techadventures.net>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
KASAN uses different routines to map shadow for hot added memory and
memory obtained in boot process. Attempt to offline memory onlined by
normal boot process leads to this:
Trying to vfree() nonexistent vm area (000000005d3b34b9)
WARNING: CPU: 2 PID: 13215 at mm/vmalloc.c:1525 __vunmap+0x147/0x190
Call Trace:
kasan_mem_notifier+0xad/0xb9
notifier_call_chain+0x166/0x260
__blocking_notifier_call_chain+0xdb/0x140
__offline_pages+0x96a/0xb10
memory_subsys_offline+0x76/0xc0
device_offline+0xb8/0x120
store_mem_state+0xfa/0x120
kernfs_fop_write+0x1d5/0x320
__vfs_write+0xd4/0x530
vfs_write+0x105/0x340
SyS_write+0xb0/0x140
Obviously we can't call vfree() to free memory that wasn't allocated via
vmalloc(). Use find_vm_area() to see if we can call vfree().
Unfortunately it's a bit tricky to properly unmap and free shadow
allocated during boot, so we'll have to keep it. If memory will come
online again that shadow will be reused.
Matthew asked: how can you call vfree() on something that isn't a
vmalloc address?
vfree() is able to free any address returned by
__vmalloc_node_range(). And __vmalloc_node_range() gives you any
address you ask. It doesn't have to be an address in [VMALLOC_START,
VMALLOC_END] range.
That's also how the module_alloc()/module_memfree() works on
architectures that have designated area for modules.
[aryabinin@virtuozzo.com: improve comments]
Link: http://lkml.kernel.org/r/dabee6ab-3a7a-51cd-3b86-5468718e0390@virtuozzo.com
[akpm@linux-foundation.org: fix typos, reflow comment]
Link: http://lkml.kernel.org/r/20180201163349.8700-1-aryabinin@virtuozzo.com
Fixes: fa69b5989b ("mm/kasan: add support for memory hotplug")
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reported-by: Paul Menzel <pmenzel+linux-kasan-dev@molgen.mpg.de>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If swapon() fails after incrementing nr_rotate_swap, we don't decrement
it and thus effectively leak it. Make sure we decrement it if we
incremented it.
Link: http://lkml.kernel.org/r/b6fe6b879f17fa68eee6cbd876f459f6e5e33495.1526491581.git.osandov@fb.com
Fixes: 81a0298bdf ("mm, swap: don't use VMA based swap readahead if HDD is used as swap")
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Rik van Riel <riel@surriel.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts the following commits that change CMA design in MM.
3d2054ad8c ("ARM: CMA: avoid double mapping to the CMA area if CONFIG_HIGHMEM=y")
1d47a3ec09 ("mm/cma: remove ALLOC_CMA")
bad8c6c0b1 ("mm/cma: manage the memory of the CMA area by using the ZONE_MOVABLE")
Ville reported a following error on i386.
Inode-cache hash table entries: 65536 (order: 6, 262144 bytes)
microcode: microcode updated early to revision 0x4, date = 2013-06-28
Initializing CPU#0
Initializing HighMem for node 0 (000377fe:00118000)
Initializing Movable for node 0 (00000001:00118000)
BUG: Bad page state in process swapper pfn:377fe
page:f53effc0 count:0 mapcount:-127 mapping:00000000 index:0x0
flags: 0x80000000()
raw: 80000000 00000000 00000000 ffffff80 00000000 00000100 00000200 00000001
page dumped because: nonzero mapcount
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 4.17.0-rc5-elk+ #145
Hardware name: Dell Inc. Latitude E5410/03VXMC, BIOS A15 07/11/2013
Call Trace:
dump_stack+0x60/0x96
bad_page+0x9a/0x100
free_pages_check_bad+0x3f/0x60
free_pcppages_bulk+0x29d/0x5b0
free_unref_page_commit+0x84/0xb0
free_unref_page+0x3e/0x70
__free_pages+0x1d/0x20
free_highmem_page+0x19/0x40
add_highpages_with_active_regions+0xab/0xeb
set_highmem_pages_init+0x66/0x73
mem_init+0x1b/0x1d7
start_kernel+0x17a/0x363
i386_start_kernel+0x95/0x99
startup_32_smp+0x164/0x168
The reason for this error is that the span of MOVABLE_ZONE is extended
to whole node span for future CMA initialization, and, normal memory is
wrongly freed here. I submitted the fix and it seems to work, but,
another problem happened.
It's so late time to fix the later problem so I decide to reverting the
series.
Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Laura Abbott <labbott@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
From 0aa2e9b921d6db71150633ff290199554f0842a8 Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@kernel.org>
Date: Wed, 23 May 2018 10:29:00 -0700
cgwb_release() punts the actual release to cgwb_release_workfn() on
system_wq. Depending on the number of cgroups or block devices, there
can be a lot of cgwb_release_workfn() in flight at the same time.
We're periodically seeing close to 256 kworkers getting stuck with the
following stack trace and overtime the entire system gets stuck.
[<ffffffff810ee40c>] _synchronize_rcu_expedited.constprop.72+0x2fc/0x330
[<ffffffff810ee634>] synchronize_rcu_expedited+0x24/0x30
[<ffffffff811ccf23>] bdi_unregister+0x53/0x290
[<ffffffff811cd1e9>] release_bdi+0x89/0xc0
[<ffffffff811cd645>] wb_exit+0x85/0xa0
[<ffffffff811cdc84>] cgwb_release_workfn+0x54/0xb0
[<ffffffff810a68d0>] process_one_work+0x150/0x410
[<ffffffff810a71fd>] worker_thread+0x6d/0x520
[<ffffffff810ad3dc>] kthread+0x12c/0x160
[<ffffffff81969019>] ret_from_fork+0x29/0x40
[<ffffffffffffffff>] 0xffffffffffffffff
The events leading to the lockup are...
1. A lot of cgwb_release_workfn() is queued at the same time and all
system_wq kworkers are assigned to execute them.
2. They all end up calling synchronize_rcu_expedited(). One of them
wins and tries to perform the expedited synchronization.
3. However, that invovles queueing rcu_exp_work to system_wq and
waiting for it. Because #1 is holding all available kworkers on
system_wq, rcu_exp_work can't be executed. cgwb_release_workfn()
is waiting for synchronize_rcu_expedited() which in turn is waiting
for cgwb_release_workfn() to free up some of the kworkers.
We shouldn't be scheduling hundreds of cgwb_release_workfn() at the
same time. There's nothing to be gained from that. This patch
updates cgwb release path to use a dedicated percpu workqueue with
@max_active of 1.
While this resolves the problem at hand, it might be a good idea to
isolate rcu_exp_work to its own workqueue too as it can be used from
various paths and is prone to this sort of indirect A-A deadlocks.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Commit be83bbf806 ("mmap: introduce sane default mmap limits") was
introduced to catch problems in various ad-hoc character device drivers
doing mmap and getting the size limits wrong. In the process, it used
"known good" limits for the normal cases of mapping regular files and
block device drivers.
It turns out that the "s_maxbytes" limit was less "known good" than I
thought. In particular, /proc doesn't set it, but exposes one regular
file to mmap: /proc/vmcore. As a result, that file got limited to the
default MAX_INT s_maxbytes value.
This went unnoticed for a while, because apparently the only thing that
needs it is the s390 kernel zfcpdump, but there might be other tools
that use this too.
Vasily suggested just changing s_maxbytes for all of /proc, which isn't
wrong, but makes me nervous at this stage. So instead, just make the
new mmap limit always be MAX_LFS_FILESIZE for regular files, which won't
affect anything else. It wasn't the regular file case I was worried
about.
I'd really prefer for maxsize to have been per-inode, but that is not
how things are today.
Fixes: be83bbf806 ("mmap: introduce sane default mmap limits")
Reported-by: Vasily Gorbik <gor@linux.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It is unsafe to do virtual to physical translations before mm_init() is
called if struct page is needed in order to determine the memory section
number (see SECTION_IN_PAGE_FLAGS). This is because only in mm_init()
we initialize struct pages for all the allocated memory when deferred
struct pages are used.
My recent fix in commit c9e97a1997 ("mm: initialize pages on demand
during boot") exposed this problem, because it greatly reduced number of
pages that are initialized before mm_init(), but the problem existed
even before my fix, as Fengguang Wu found.
Below is a more detailed explanation of the problem.
We initialize struct pages in four places:
1. Early in boot a small set of struct pages is initialized to fill the
first section, and lower zones.
2. During mm_init() we initialize "struct pages" for all the memory that
is allocated, i.e reserved in memblock.
3. Using on-demand logic when pages are allocated after mm_init call
(when memblock is finished)
4. After smp_init() when the rest free deferred pages are initialized.
The problem occurs if we try to do va to phys translation of a memory
between steps 1 and 2. Because we have not yet initialized struct pages
for all the reserved pages, it is inherently unsafe to do va to phys if
the translation itself requires access of "struct page" as in case of
this combination: CONFIG_SPARSE && !CONFIG_SPARSE_VMEMMAP
The following path exposes the problem:
start_kernel()
trap_init()
setup_cpu_entry_areas()
setup_cpu_entry_area(cpu)
get_cpu_gdt_paddr(cpu)
per_cpu_ptr_to_phys(addr)
pcpu_addr_to_page(addr)
virt_to_page(addr)
pfn_to_page(__pa(addr) >> PAGE_SHIFT)
We disable this path by not allowing NEED_PER_CPU_KM with deferred
struct pages feature.
The problems are discussed in these threads:
http://lkml.kernel.org/r/20180418135300.inazvpxjxowogyge@wfg-t540p.sh.intel.comhttp://lkml.kernel.org/r/20180419013128.iurzouiqxvcnpbvz@wfg-t540p.sh.intel.comhttp://lkml.kernel.org/r/20180426202619.2768-1-pasha.tatashin@oracle.com
Link: http://lkml.kernel.org/r/20180515175124.1770-1-pasha.tatashin@oracle.com
Fixes: 3a80a7fa79 ("mm: meminit: initialise a subset of struct pages if CONFIG_DEFERRED_STRUCT_PAGE_INIT is set")
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Dennis Zhou <dennisszhou@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>
proc_pid_cmdline_read() and environ_read() directly access the target
process' VM to retrieve the command line and environment. If this
process remaps these areas onto a file via mmap(), the requesting
process may experience various issues such as extra delays if the
underlying device is slow to respond.
Let's simply refuse to access file-backed areas in these functions.
For this we add a new FOLL_ANON gup flag that is passed to all calls
to access_remote_vm(). The code already takes care of such failures
(including unmapped areas). Accesses via /proc/pid/mem were not
changed though.
This was assigned CVE-2018-1120.
Note for stable backports: the patch may apply to kernels prior to 4.11
but silently miss one location; it must be checked that no call to
access_remote_vm() keeps zero as the last argument.
Reported-by: Qualys Security Advisory <qsa@qualys.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Variant of proc_create_data that directly take a struct seq_operations
argument + a private state size and drastically reduces the boilerplate
code in the callers.
All trivial callers converted over.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Variants of proc_create{,_data} that directly take a struct seq_operations
argument and drastically reduces the boilerplate code in the callers.
All trivial callers converted over.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Allows mempools to be embedded in other structs, getting rid of a
pointer indirection from allocation fastpaths.
mempool_exit() is safe to call on an uninitialized but zeroed mempool.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Merge misc fixes from Andrew Morton:
"13 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
rbtree: include rcu.h
scripts/faddr2line: fix error when addr2line output contains discriminator
ocfs2: take inode cluster lock before moving reflinked inode from orphan dir
mm, oom: fix concurrent munlock and oom reaper unmap, v3
mm: migrate: fix double call of radix_tree_replace_slot()
proc/kcore: don't bounds check against address 0
mm: don't show nr_indirectly_reclaimable in /proc/vmstat
mm: sections are not offlined during memory hotremove
z3fold: fix reclaim lock-ups
init: fix false positives in W+X checking
lib/find_bit_benchmark.c: avoid soft lockup in test_find_first_bit()
KASAN: prohibit KASAN+STRUCTLEAK combination
MAINTAINERS: update Shuah's email address
Since exit_mmap() is done without the protection of mm->mmap_sem, it is
possible for the oom reaper to concurrently operate on an mm until
MMF_OOM_SKIP is set.
This allows munlock_vma_pages_all() to concurrently run while the oom
reaper is operating on a vma. Since munlock_vma_pages_range() depends
on clearing VM_LOCKED from vm_flags before actually doing the munlock to
determine if any other vmas are locking the same memory, the check for
VM_LOCKED in the oom reaper is racy.
This is especially noticeable on architectures such as powerpc where
clearing a huge pmd requires serialize_against_pte_lookup(). If the pmd
is zapped by the oom reaper during follow_page_mask() after the check
for pmd_none() is bypassed, this ends up deferencing a NULL ptl or a
kernel oops.
Fix this by manually freeing all possible memory from the mm before
doing the munlock and then setting MMF_OOM_SKIP. The oom reaper can not
run on the mm anymore so the munlock is safe to do in exit_mmap(). It
also matches the logic that the oom reaper currently uses for
determining when to set MMF_OOM_SKIP itself, so there's no new risk of
excessive oom killing.
This issue fixes CVE-2018-1000200.
Link: http://lkml.kernel.org/r/alpine.DEB.2.21.1804241526320.238665@chino.kir.corp.google.com
Fixes: 2129258024 ("mm: oom: let oom_reap_task and exit_mmap run concurrently")
Signed-off-by: David Rientjes <rientjes@google.com>
Suggested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org> [4.14+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
radix_tree_replace_slot() is called twice for head page, it's obviously
a bug. Let's fix it.
Link: http://lkml.kernel.org/r/20180423072101.GA12157@hori1.linux.bs1.fc.nec.co.jp
Fixes: e71769ae52 ("mm: enable thp migration for shmem thp")
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reported-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Zi Yan <zi.yan@sent.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Don't show nr_indirectly_reclaimable in /proc/vmstat, because there is
no need to export this vm counter to userspace, and some changes are
expected in reclaimable object accounting, which can alter this counter.
Link: http://lkml.kernel.org/r/20180425191422.9159-1-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Memory hotplug and hotremove operate with per-block granularity. If the
machine has a large amount of memory (more than 64G), the size of a
memory block can span multiple sections. By mistake, during hotremove
we set only the first section to offline state.
The bug was discovered because kernel selftest started to fail:
https://lkml.kernel.org/r/20180423011247.GK5563@yexl-desktop
After commit, "mm/memory_hotplug: optimize probe routine". But, the bug
is older than this commit. In this optimization we also added a check
for sections to be in a proper state during hotplug operation.
Link: http://lkml.kernel.org/r/20180427145257.15222-1-pasha.tatashin@oracle.com
Fixes: 2d070eab2e ("mm: consider zone which is not fully populated to have holes")
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Do not try to optimize in-page object layout while the page is under
reclaim. This fixes lock-ups on reclaim and improves reclaim
performance at the same time.
[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20180430125800.444cae9706489f412ad12621@gmail.com
Signed-off-by: Vitaly Wool <vitaly.vul@sony.com>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Cc: <Oleksiy.Avramchenko@sony.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The internal VM "mmap()" interfaces are based on the mmap target doing
everything using page indexes rather than byte offsets, because
traditionally (ie 32-bit) we had the situation that the byte offset
didn't fit in a register. So while the mmap virtual address was limited
by the word size of the architecture, the backing store was not.
So we're basically passing "pgoff" around as a page index, in order to
be able to describe backing store locations that are much bigger than
the word size (think files larger than 4GB etc).
But while this all makes a ton of sense conceptually, we've been dogged
by various drivers that don't really understand this, and internally
work with byte offsets, and then try to work with the page index by
turning it into a byte offset with "pgoff << PAGE_SHIFT".
Which obviously can overflow.
Adding the size of the mapping to it to get the byte offset of the end
of the backing store just exacerbates the problem, and if you then use
this overflow-prone value to check various limits of your device driver
mmap capability, you're just setting yourself up for problems.
The correct thing for drivers to do is to do their limit math in page
indices, the way the interface is designed. Because the generic mmap
code _does_ test that the index doesn't overflow, since that's what the
mmap code really cares about.
HOWEVER.
Finding and fixing various random drivers is a sisyphean task, so let's
just see if we can just make the core mmap() code do the limiting for
us. Realistically, the only "big" backing stores we need to care about
are regular files and block devices, both of which are known to do this
properly, and which have nice well-defined limits for how much data they
can access.
So let's special-case just those two known cases, and then limit other
random mmap users to a backing store that still fits in "unsigned long".
Realistically, that's not much of a limit at all on 64-bit, and on
32-bit architectures the only worry might be the GPU drivers, which can
have big physical address spaces.
To make it possible for drivers like that to say that they are 64-bit
clean, this patch does repurpose the "FMODE_UNSIGNED_OFFSET" bit in the
file flags to allow drivers to mark their file descriptors as safe in
the full 64-bit mmap address space.
[ The timing for doing this is less than optimal, and this should really
go in a merge window. But realistically, this needs wide testing more
than it needs anything else, and being main-line is the only way to do
that.
So the earlier the better, even if it's outside the proper development
cycle - Linus ]
Cc: Kees Cook <keescook@chromium.org>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Dave Airlie <airlied@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Instead select the PHYS_ADDR_T_64BIT for 32-bit architectures that need a
64-bit phys_addr_t type directly.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: James Hogan <jhogan@kernel.org>
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Merge tag 'for-linus-20180504' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
"A collection of fixes that should to into this release. This contains:
- Set of bcache fixes from Coly, fixing regression in patches that
went into this series.
- Set of NVMe fixes by way of Keith.
- Set of bdi related fixes, one from Jan and two from Tetsuo Handa,
fixing various issues around device addition/removal.
- Two block inflight fixes from Omar, fixing issues around the
transition to using tags for blk-mq inflight accounting that we
did a few releases ago"
* tag 'for-linus-20180504' of git://git.kernel.dk/linux-block:
bdi: Fix oops in wb_workfn()
nvmet: switch loopback target state to connecting when resetting
nvme/multipath: Fix multipath disabled naming collisions
nvme/multipath: Disable runtime writable enabling parameter
nvme: Set integrity flag for user passthrough commands
nvme: fix potential memory leak in option parsing
bdi: Fix use after free bug in debugfs_remove()
bdi: wake up concurrent wb_shutdown() callers.
bcache: use pr_info() to inform duplicated CACHE_SET_IO_DISABLE set
bcache: set dc->io_disable to true in conditional_stop_bcache_device()
bcache: add wait_for_kthread_stop() in bch_allocator_thread()
bcache: count backing device I/O error for writeback I/O
bcache: set CACHE_SET_IO_DISABLE in bch_cached_dev_error()
bcache: store disk name in struct cache and struct cached_dev
blk-mq: fix sysfs inflight counter
blk-mq: count allocated but not started requests in iostats inflight
syzbot is reporting use after free bug in debugfs_remove() [1].
This is because fault injection made memory allocation for
debugfs_create_file() from bdi_debug_register() from bdi_register_va()
fail and continued with setting WB_registered. But when debugfs_remove()
is called from debugfs_remove(bdi->debug_dir) from bdi_debug_unregister()
from bdi_unregister() from release_bdi() because WB_registered was set
by bdi_register_va(), IS_ERR_OR_NULL(bdi->debug_dir) == false despite
debugfs_remove(bdi->debug_dir) was already called from bdi_register_va().
Fix this by making IS_ERR_OR_NULL(bdi->debug_dir) == true.
[1] https://syzkaller.appspot.com/bug?id=5ab4efd91a96dcea9b68104f159adf4af2a6dfc1
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: syzbot <syzbot+049cb4ae097049dac137@syzkaller.appspotmail.com>
Fixes: 97f0769793 ("bdi: convert bdi_debug_register to int")
Cc: weiping zhang <zhangweiping@didichuxing.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
syzbot is reporting hung tasks at wait_on_bit(WB_shutting_down) in
wb_shutdown() [1]. This seems to be because commit 5318ce7d46 ("bdi:
Shutdown writeback on all cgwbs in cgwb_bdi_destroy()") forgot to call
wake_up_bit(WB_shutting_down) after clear_bit(WB_shutting_down).
Introduce a helper function clear_and_wake_up_bit() and use it, in order
to avoid similar errors in future.
[1] https://syzkaller.appspot.com/bug?id=b297474817af98d5796bc544e1bb806fc3da0e5e
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: syzbot <syzbot+c0cf869505e03bdf1a24@syzkaller.appspotmail.com>
Fixes: 5318ce7d46 ("bdi: Shutdown writeback on all cgwbs in cgwb_bdi_destroy()")
Cc: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The existing comment provides a good overview of KSM implementation. Let's
update it to reflect recent additions of "chain" and "dup" variants of the
stable tree nodes and mark it as "DOC:" for inclusion into the KSM
documentation.
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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Merge tag 'v4.17-rc2' into docs-next
Merge -rc2 to pick up the changes to
Documentation/core-api/kernel-api.rst that hit mainline via the
networking tree. In their absence, subsequent patches cannot be
applied.
Several documents in Documentation/vm fit quite well into the "admin/user
guide" category. The documents that don't overload the reader with lots of
implementation details and provide coherent description of certain feature
can be moved to Documentation/admin-guide/mm.
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
commit ce9962bf7e22bb3891655c349faff618922d4a73
0day reported warnings at boot on 32-bit systems without NX support:
attempted to set unsupported pgprot: 8000000000000025 bits: 8000000000000000 supported: 7fffffffffffffff
WARNING: CPU: 0 PID: 1 at
arch/x86/include/asm/pgtable.h:540 handle_mm_fault+0xfc1/0xfe0:
check_pgprot at arch/x86/include/asm/pgtable.h:535
(inlined by) pfn_pte at arch/x86/include/asm/pgtable.h:549
(inlined by) do_anonymous_page at mm/memory.c:3169
(inlined by) handle_pte_fault at mm/memory.c:3961
(inlined by) __handle_mm_fault at mm/memory.c:4087
(inlined by) handle_mm_fault at mm/memory.c:4124
The problem is that due to the recent commit which removed auto-massaging
of page protections, filtering page permissions at PTE creation time is not
longer done, so vma->vm_page_prot is passed unfiltered to PTE creation.
Filter the page protections before they are installed in vma->vm_page_prot.
Fixes: fb43d6cb91 ("x86/mm: Do not auto-massage page protections")
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@google.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: linux-mm@kvack.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Nadav Amit <namit@vmware.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Link: https://lkml.kernel.org/r/20180420222028.99D72858@viggo.jf.intel.com
f2fs specifies the __GFP_ZERO flag for allocating some of its pages.
Unfortunately, the page cache also uses the mapping's GFP flags for
allocating radix tree nodes. It always masked off the __GFP_HIGHMEM
flag, and masks off __GFP_ZERO in some paths, but not all. That causes
radix tree nodes to be allocated with a NULL list_head, which causes
backtraces like:
__list_del_entry+0x30/0xd0
list_lru_del+0xac/0x1ac
page_cache_tree_insert+0xd8/0x110
The __GFP_DMA and __GFP_DMA32 flags would also be able to sneak through
if they are ever used. Fix them all by using GFP_RECLAIM_MASK at the
innermost location, and remove it from earlier in the callchain.
Link: http://lkml.kernel.org/r/20180411060320.14458-2-willy@infradead.org
Fixes: 449dd6984d ("mm: keep page cache radix tree nodes in check")
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Reported-by: Chris Fries <cfries@google.com>
Debugged-by: Minchan Kim <minchan@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
My testing for the latest kernel supporting thp migration showed an
infinite loop in offlining the memory block that is filled with shmem
thps. We can get out of the loop with a signal, but kernel should return
with failure in this case.
What happens in the loop is that scan_movable_pages() repeats returning
the same pfn without any progress. That's because page migration always
fails for shmem thps.
In memory offline code, memory blocks containing unmovable pages should be
prevented from being offline targets by has_unmovable_pages() inside
start_isolate_page_range(). So it's possible to change migratability for
non-anonymous thps to avoid the issue, but it introduces more complex and
thp-specific handling in migration code, so it might not good.
So this patch is suggesting to fix the issue by enabling thp migration for
shmem thp. Both of anon/shmem thp are migratable so we don't need
precheck about the type of thps.
Link: http://lkml.kernel.org/r/20180406030706.GA2434@hori1.linux.bs1.fc.nec.co.jp
Fixes: commit 72b39cfc4d ("mm, memory_hotplug: do not fail offlining too early")
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Zi Yan <zi.yan@sent.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
lock_page_memcg()/unlock_page_memcg() use spin_lock_irqsave/restore() if
the page's memcg is undergoing move accounting, which occurs when a
process leaves its memcg for a new one that has
memory.move_charge_at_immigrate set.
unlocked_inode_to_wb_begin,end() use spin_lock_irq/spin_unlock_irq() if
the given inode is switching writeback domains. Switches occur when
enough writes are issued from a new domain.
This existing pattern is thus suspicious:
lock_page_memcg(page);
unlocked_inode_to_wb_begin(inode, &locked);
...
unlocked_inode_to_wb_end(inode, locked);
unlock_page_memcg(page);
If both inode switch and process memcg migration are both in-flight then
unlocked_inode_to_wb_end() will unconditionally enable interrupts while
still holding the lock_page_memcg() irq spinlock. This suggests the
possibility of deadlock if an interrupt occurs before unlock_page_memcg().
truncate
__cancel_dirty_page
lock_page_memcg
unlocked_inode_to_wb_begin
unlocked_inode_to_wb_end
<interrupts mistakenly enabled>
<interrupt>
end_page_writeback
test_clear_page_writeback
lock_page_memcg
<deadlock>
unlock_page_memcg
Due to configuration limitations this deadlock is not currently possible
because we don't mix cgroup writeback (a cgroupv2 feature) and
memory.move_charge_at_immigrate (a cgroupv1 feature).
If the kernel is hacked to always claim inode switching and memcg
moving_account, then this script triggers lockup in less than a minute:
cd /mnt/cgroup/memory
mkdir a b
echo 1 > a/memory.move_charge_at_immigrate
echo 1 > b/memory.move_charge_at_immigrate
(
echo $BASHPID > a/cgroup.procs
while true; do
dd if=/dev/zero of=/mnt/big bs=1M count=256
done
) &
while true; do
sync
done &
sleep 1h &
SLEEP=$!
while true; do
echo $SLEEP > a/cgroup.procs
echo $SLEEP > b/cgroup.procs
done
The deadlock does not seem possible, so it's debatable if there's any
reason to modify the kernel. I suggest we should to prevent future
surprises. And Wang Long said "this deadlock occurs three times in our
environment", so there's more reason to apply this, even to stable.
Stable 4.4 has minor conflicts applying this patch. For a clean 4.4 patch
see "[PATCH for-4.4] writeback: safer lock nesting"
https://lkml.org/lkml/2018/4/11/146
Wang Long said "this deadlock occurs three times in our environment"
[gthelen@google.com: v4]
Link: http://lkml.kernel.org/r/20180411084653.254724-1-gthelen@google.com
[akpm@linux-foundation.org: comment tweaks, struct initialization simplification]
Change-Id: Ibb773e8045852978f6207074491d262f1b3fb613
Link: http://lkml.kernel.org/r/20180410005908.167976-1-gthelen@google.com
Fixes: 682aa8e1a6 ("writeback: implement unlocked_inode_to_wb transaction and use it for stat updates")
Signed-off-by: Greg Thelen <gthelen@google.com>
Reported-by: Wang Long <wanglong19@meituan.com>
Acked-by: Wang Long <wanglong19@meituan.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: <stable@vger.kernel.org> [v4.2+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Li Wang has reported that LTP move_pages04 test fails with the current
tree:
LTP move_pages04:
TFAIL : move_pages04.c:143: status[1] is EPERM, expected EFAULT
The test allocates an array of two pages, one is present while the other
is not (resp. backed by zero page) and it expects EFAULT for the second
page as the man page suggests. We are reporting EPERM which doesn't make
any sense and this is a result of a bug from cf5f16b23ec9 ("mm: unclutter
THP migration").
do_pages_move tries to handle as many pages in one batch as possible so we
queue all pages with the same node target together and that corresponds to
[start, i] range which is then used to update status array.
add_page_for_migration will correctly notice the zero (resp. !present)
page and returns with EFAULT which gets written to the status. But if
this is the last page in the array we do not update start and so the last
store_status after the loop will overwrite the range of the last batch
with NUMA_NO_NODE (which corresponds to EPERM).
Fix this by simply bailing out from the last flush if the pagelist is
empty as there is clearly nothing more to do.
Link: http://lkml.kernel.org/r/20180418121255.334-1-mhocko@kernel.org
Fixes: cf5f16b23ec9 ("mm: unclutter THP migration")
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Li Wang <liwang@redhat.com>
Tested-by: Li Wang <liwang@redhat.com>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike Rapoport says:
These patches convert files in Documentation/vm to ReST format, add an
initial index and link it to the top level documentation.
There are no contents changes in the documentation, except few spelling
fixes. The relatively large diffstat stems from the indentation and
paragraph wrapping changes.
I've tried to keep the formatting as consistent as possible, but I could
miss some places that needed markup and add some markup where it was not
necessary.
[jc: significant conflicts in vm/hmm.rst]
syzbot is catching so many bugs triggered by commit 9ee332d99e
("sget(): handle failures of register_shrinker()"). That commit expected
that calling kill_sb() from deactivate_locked_super() without successful
fill_super() is safe, but the reality was different; some callers assign
attributes which are needed for kill_sb() after sget() succeeds.
For example, [1] is a report where sb->s_mode (which seems to be either
FMODE_READ | FMODE_EXCL | FMODE_WRITE or FMODE_READ | FMODE_EXCL) is not
assigned unless sget() succeeds. But it does not worth complicate sget()
so that register_shrinker() failure path can safely call
kill_block_super() via kill_sb(). Making alloc_super() fail if memory
allocation for register_shrinker() failed is much simpler. Let's avoid
calling deactivate_locked_super() from sget_userns() by preallocating
memory for the shrinker and making register_shrinker() in sget_userns()
never fail.
[1] https://syzkaller.appspot.com/bug?id=588996a25a2587be2e3a54e8646728fb9cae44e7
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: syzbot <syzbot+5a170e19c963a2e0df79@syzkaller.appspotmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
cache_reap() is initially scheduled in start_cpu_timer() via
schedule_delayed_work_on(). But then the next iterations are scheduled
via schedule_delayed_work(), i.e. using WORK_CPU_UNBOUND.
Thus since commit ef55718044 ("workqueue: schedule WORK_CPU_UNBOUND
work on wq_unbound_cpumask CPUs") there is no guarantee the future
iterations will run on the originally intended cpu, although it's still
preferred. I was able to demonstrate this with
/sys/module/workqueue/parameters/debug_force_rr_cpu. IIUC, it may also
happen due to migrating timers in nohz context. As a result, some cpu's
would be calling cache_reap() more frequently and others never.
This patch uses schedule_delayed_work_on() with the current cpu when
scheduling the next iteration.
Link: http://lkml.kernel.org/r/20180411070007.32225-1-vbabka@suse.cz
Fixes: ef55718044 ("workqueue: schedule WORK_CPU_UNBOUND work on wq_unbound_cpumask CPUs")
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Pekka Enberg <penberg@kernel.org>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Building orangefs on MMU-less machines now results in a link error
because of the newly introduced use of the filemap_page_mkwrite()
function:
ERROR: "filemap_page_mkwrite" [fs/orangefs/orangefs.ko] undefined!
This adds a dummy version for it, similar to the existing
generic_file_mmap and generic_file_readonly_mmap stubs in the same file,
to avoid the link error without adding #ifdefs in each file system that
uses these.
Link: http://lkml.kernel.org/r/20180409105555.2439976-1-arnd@arndb.de
Fixes: a5135eeab2 ("orangefs: implement vm_ops->fault")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Martin Brandenburg <martin@omnibond.com>
Cc: Mike Marshall <hubcap@omnibond.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__get_user_pages_fast handles errors differently from
get_user_pages_fast: the former always returns the number of pages
pinned, the later might return a negative error code.
Link: http://lkml.kernel.org/r/1522962072-182137-6-git-send-email-mst@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
get_user_pages_fast is supposed to be a faster drop-in equivalent of
get_user_pages. As such, callers expect it to return a negative return
code when passed an invalid address, and never expect it to return 0
when passed a positive number of pages, since its documentation says:
* Returns number of pages pinned. This may be fewer than the number
* requested. If nr_pages is 0 or negative, returns 0. If no pages
* were pinned, returns -errno.
When get_user_pages_fast fall back on get_user_pages this is exactly
what happens. Unfortunately the implementation is inconsistent: it
returns 0 if passed a kernel address, confusing callers: for example,
the following is pretty common but does not appear to do the right thing
with a kernel address:
ret = get_user_pages_fast(addr, 1, writeable, &page);
if (ret < 0)
return ret;
Change get_user_pages_fast to return -EFAULT when supplied a kernel
address to make it match expectations.
All callers have been audited for consistency with the documented
semantics.
Link: http://lkml.kernel.org/r/1522962072-182137-4-git-send-email-mst@redhat.com
Fixes: 5b65c4677a ("mm, x86/mm: Fix performance regression in get_user_pages_fast()")
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reported-by: syzbot+6304bf97ef436580fede@syzkaller.appspotmail.com
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm/get_user_pages_fast fixes, cleanups", v2.
Turns out get_user_pages_fast and __get_user_pages_fast return different
values on error when given a single page: __get_user_pages_fast returns
0. get_user_pages_fast returns either 0 or an error.
Callers of get_user_pages_fast expect an error so fix it up to return an
error consistently.
Stress the difference between get_user_pages_fast and
__get_user_pages_fast to make sure callers aren't confused.
This patch (of 3):
__gup_benchmark_ioctl does not handle the case where get_user_pages_fast
fails:
- a negative return code will cause a buffer overrun
- returning with partial success will cause use of uninitialized
memory.
[akpm@linux-foundation.org: simplification]
Link: http://lkml.kernel.org/r/1522962072-182137-3-git-send-email-mst@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
