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more than once
commit 3d7fed4ad8ccb691d217efbb0f934e6a4df5ef91 upstream.
Mmap /dev/dax more than once, then read the poison location using
address from one of the mappings. The other mappings due to not having
the page mapped in will cause SIGKILLs delivered to the process.
SIGKILL succeeds over SIGBUS, so user process loses the opportunity to
handle the UE.
Although one may add MAP_POPULATE to mmap(2) to work around the issue,
MAP_POPULATE makes mapping 128GB of pmem several magnitudes slower, so
isn't always an option.
Details -
ndctl inject-error --block=10 --count=1 namespace6.0
./read_poison -x dax6.0 -o 5120 -m 2
mmaped address 0x7f5bb6600000
mmaped address 0x7f3cf3600000
doing local read at address 0x7f3cf3601400
Killed
Console messages in instrumented kernel -
mce: Uncorrected hardware memory error in user-access at edbe201400
Memory failure: tk->addr = 7f5bb6601000
Memory failure: address edbe201: call dev_pagemap_mapping_shift
dev_pagemap_mapping_shift: page edbe201: no PUD
Memory failure: tk->size_shift == 0
Memory failure: Unable to find user space address edbe201 in read_poison
Memory failure: tk->addr = 7f3cf3601000
Memory failure: address edbe201: call dev_pagemap_mapping_shift
Memory failure: tk->size_shift = 21
Memory failure: 0xedbe201: forcibly killing read_poison:22434 because of failure to unmap corrupted page
=> to deliver SIGKILL
Memory failure: 0xedbe201: Killing read_poison:22434 due to hardware memory corruption
=> to deliver SIGBUS
Link: http://lkml.kernel.org/r/1565112345-28754-3-git-send-email-jane.chu@oracle.com
Signed-off-by: Jane Chu <jane.chu@oracle.com>
Suggested-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Michal Hocko <mhocko@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>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
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commit f231fe4235e22e18d847e05cbe705deaca56580a upstream.
Uninitialized memmaps contain garbage and in the worst case trigger
kernel BUGs, especially with CONFIG_PAGE_POISONING. They should not get
touched.
Let's make sure that we only consider online memory (managed by the
buddy) that has initialized memmaps. ZONE_DEVICE is not applicable.
page_zone() will call page_to_nid(), which will trigger
VM_BUG_ON_PGFLAGS(PagePoisoned(page), page) with CONFIG_PAGE_POISONING
and CONFIG_DEBUG_VM_PGFLAGS when called on uninitialized memmaps. This
can be the case when an offline memory block (e.g., never onlined) is
spanned by a zone.
Note: As explained by Michal in [1], alloc_contig_range() will verify
the range. So it boils down to the wrong access in this function.
[1] http://lkml.kernel.org/r/20180423000943.GO17484@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/20191015120717.4858-1-david@redhat.com
Fixes: f1dd2cd13c4b ("mm, memory_hotplug: do not associate hotadded memory to zones until online") [visible after d0dc12e86b319]
Signed-off-by: David Hildenbrand <david@redhat.com>
Reported-by: Michal Hocko <mhocko@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: <stable@vger.kernel.org> [4.13+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
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commit f3057ad767542be7bbac44e548cb44017178a163 upstream.
Until commit 92d12f9544b7 ("memblock: refactor internal allocation
functions") the maximal address for memblock allocations was forced to
memblock.current_limit only for the allocation functions returning
virtual address. The changes introduced by that commit moved the limit
enforcement into the allocation core and as a result the allocation
functions returning physical address also started to limit allocations
to memblock.current_limit.
This caused breakage of etnaviv GPU driver:
etnaviv etnaviv: bound 130000.gpu (ops gpu_ops)
etnaviv etnaviv: bound 134000.gpu (ops gpu_ops)
etnaviv etnaviv: bound 2204000.gpu (ops gpu_ops)
etnaviv-gpu 130000.gpu: model: GC2000, revision: 5108
etnaviv-gpu 130000.gpu: command buffer outside valid memory window
etnaviv-gpu 134000.gpu: model: GC320, revision: 5007
etnaviv-gpu 134000.gpu: command buffer outside valid memory window
etnaviv-gpu 2204000.gpu: model: GC355, revision: 1215
etnaviv-gpu 2204000.gpu: Ignoring GPU with VG and FE2.0
Restore the behaviour of memblock_phys* family so that these functions
will not enforce memblock.current_limit.
Link: http://lkml.kernel.org/r/1570915861-17633-1-git-send-email-rppt@kernel.org
Fixes: 92d12f9544b7 ("memblock: refactor internal allocation functions")
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reported-by: Adam Ford <aford173@gmail.com>
Tested-by: Adam Ford <aford173@gmail.com> [imx6q-logicpd]
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
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lru_zone_size
commit b11edebbc967ebf5c55b8f9e1d5bb6d68ec3a7fd upstream.
Commit 1a61ab8038e72 ("mm: memcontrol: replace zone summing with
lruvec_page_state()") has made lruvec_page_state to use per-cpu counters
instead of calculating it directly from lru_zone_size with an idea that
this would be more effective.
Tim has reported that this is not really the case for their database
benchmark which is showing an opposite results where lruvec_page_state
is taking up a huge chunk of CPU cycles (about 25% of the system time
which is roughly 7% of total cpu cycles) on 5.3 kernels. The workload
is running on a larger machine (96cpus), it has many cgroups (500) and
it is heavily direct reclaim bound.
Tim Chen said:
: The problem can also be reproduced by running simple multi-threaded
: pmbench benchmark with a fast Optane SSD swap (see profile below).
:
:
: 6.15% 3.08% pmbench [kernel.vmlinux] [k] lruvec_lru_size
: |
: |--3.07%--lruvec_lru_size
: | |
: | |--2.11%--cpumask_next
: | | |
: | | --1.66%--find_next_bit
: | |
: | --0.57%--call_function_interrupt
: | |
: | --0.55%--smp_call_function_interrupt
: |
: |--1.59%--0x441f0fc3d009
: | _ops_rdtsc_init_base_freq
: | access_histogram
: | page_fault
: | __do_page_fault
: | handle_mm_fault
: | __handle_mm_fault
: | |
: | --1.54%--do_swap_page
: | swapin_readahead
: | swap_cluster_readahead
: | |
: | --1.53%--read_swap_cache_async
: | __read_swap_cache_async
: | alloc_pages_vma
: | __alloc_pages_nodemask
: | __alloc_pages_slowpath
: | try_to_free_pages
: | do_try_to_free_pages
: | shrink_node
: | shrink_node_memcg
: | |
: | |--0.77%--lruvec_lru_size
: | |
: | --0.76%--inactive_list_is_low
: | |
: | --0.76%--lruvec_lru_size
: |
: --1.50%--measure_read
: page_fault
: __do_page_fault
: handle_mm_fault
: __handle_mm_fault
: do_swap_page
: swapin_readahead
: swap_cluster_readahead
: |
: --1.48%--read_swap_cache_async
: __read_swap_cache_async
: alloc_pages_vma
: __alloc_pages_nodemask
: __alloc_pages_slowpath
: try_to_free_pages
: do_try_to_free_pages
: shrink_node
: shrink_node_memcg
: |
: |--0.75%--inactive_list_is_low
: | |
: | --0.75%--lruvec_lru_size
: |
: --0.73%--lruvec_lru_size
The likely culprit is the cache traffic the lruvec_page_state_local
generates. Dave Hansen says:
: I was thinking purely of the cache footprint. If it's reading
: pn->lruvec_stat_local->count[idx] is three separate cachelines, so 192
: bytes of cache *96 CPUs = 18k of data, mostly read-only. 1 cgroup would
: be 18k of data for the whole system and the caching would be pretty
: efficient and all 18k would probably survive a tight page fault loop in
: the L1. 500 cgroups would be ~90k of data per CPU thread which doesn't
: fit in the L1 and probably wouldn't survive a tight page fault loop if
: both logical threads were banging on different cgroups.
:
: It's just a theory, but it's why I noted the number of cgroups when I
: initially saw this show up in profiles
Fix the regression by partially reverting the said commit and calculate
the lru size explicitly.
Link: http://lkml.kernel.org/r/20190905071034.16822-1-honglei.wang@oracle.com
Fixes: 1a61ab8038e72 ("mm: memcontrol: replace zone summing with lruvec_page_state()")
Signed-off-by: Honglei Wang <honglei.wang@oracle.com>
Reported-by: Tim Chen <tim.c.chen@linux.intel.com>
Acked-by: Tim Chen <tim.c.chen@linux.intel.com>
Tested-by: Tim Chen <tim.c.chen@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: <stable@vger.kernel.org> [5.2+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
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commit a2e9a5afce080226edbf1882d63d99bf32070e9e upstream.
Florian and Dave reported [1] a NULL pointer dereference in
__reset_isolation_pfn(). While the exact cause is unclear, staring at
the code revealed two bugs, which might be related.
One bug is that if zone starts in the middle of pageblock, block_page
might correspond to different pfn than block_pfn, and then the
pfn_valid_within() checks will check different pfn's than those accessed
via struct page. This might result in acessing an unitialized page in
CONFIG_HOLES_IN_ZONE configs.
The other bug is that end_page refers to the first page of next
pageblock and not last page of current pageblock. The online and valid
check is then wrong and with sections, the while (page < end_page) loop
might wander off actual struct page arrays.
[1] https://lore.kernel.org/linux-xfs/87o8z1fvqu.fsf@mid.deneb.enyo.de/
Link: http://lkml.kernel.org/r/20191008152915.24704-1-vbabka@suse.cz
Fixes: 6b0868c820ff ("mm/compaction.c: correct zone boundary handling when resetting pageblock skip hints")
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reported-by: Florian Weimer <fw@deneb.enyo.de>
Reported-by: Dave Chinner <david@fromorbit.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
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/proc/pagetypeinfo
commit a26ee565b6cd8dc2bf15ff6aa70bbb28f928b773 upstream.
Uninitialized memmaps contain garbage and in the worst case trigger
kernel BUGs, especially with CONFIG_PAGE_POISONING. They should not get
touched.
For example, when not onlining a memory block that is spanned by a zone
and reading /proc/pagetypeinfo with CONFIG_DEBUG_VM_PGFLAGS and
CONFIG_PAGE_POISONING, we can trigger a kernel BUG:
:/# echo 1 > /sys/devices/system/memory/memory40/online
:/# echo 1 > /sys/devices/system/memory/memory42/online
:/# cat /proc/pagetypeinfo > test.file
page:fffff2c585200000 is uninitialized and poisoned
raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff
raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff
page dumped because: VM_BUG_ON_PAGE(PagePoisoned(p))
There is not page extension available.
------------[ cut here ]------------
kernel BUG at include/linux/mm.h:1107!
invalid opcode: 0000 [#1] SMP NOPTI
Please note that this change does not affect ZONE_DEVICE, because
pagetypeinfo_showmixedcount_print() is called from
mm/vmstat.c:pagetypeinfo_showmixedcount() only for populated zones, and
ZONE_DEVICE is never populated (zone->present_pages always 0).
[david@redhat.com: move check to outer loop, add comment, rephrase description]
Link: http://lkml.kernel.org/r/20191011140638.8160-1-david@redhat.com
Fixes: f1dd2cd13c4b ("mm, memory_hotplug: do not associate hotadded memory to zones until online") # visible after d0dc12e86b319
Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Miles Chen <miles.chen@mediatek.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org> [4.13+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
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commit e4f8e513c3d353c134ad4eef9fd0bba12406c7c8 upstream.
A long time ago we fixed a similar deadlock in show_slab_objects() [1].
However, it is apparently due to the commits like 01fb58bcba63 ("slab:
remove synchronous synchronize_sched() from memcg cache deactivation
path") and 03afc0e25f7f ("slab: get_online_mems for
kmem_cache_{create,destroy,shrink}"), this kind of deadlock is back by
just reading files in /sys/kernel/slab which will generate a lockdep
splat below.
Since the "mem_hotplug_lock" here is only to obtain a stable online node
mask while racing with NUMA node hotplug, in the worst case, the results
may me miscalculated while doing NUMA node hotplug, but they shall be
corrected by later reads of the same files.
WARNING: possible circular locking dependency detected
------------------------------------------------------
cat/5224 is trying to acquire lock:
ffff900012ac3120 (mem_hotplug_lock.rw_sem){++++}, at:
show_slab_objects+0x94/0x3a8
but task is already holding lock:
b8ff009693eee398 (kn->count#45){++++}, at: kernfs_seq_start+0x44/0xf0
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (kn->count#45){++++}:
lock_acquire+0x31c/0x360
__kernfs_remove+0x290/0x490
kernfs_remove+0x30/0x44
sysfs_remove_dir+0x70/0x88
kobject_del+0x50/0xb0
sysfs_slab_unlink+0x2c/0x38
shutdown_cache+0xa0/0xf0
kmemcg_cache_shutdown_fn+0x1c/0x34
kmemcg_workfn+0x44/0x64
process_one_work+0x4f4/0x950
worker_thread+0x390/0x4bc
kthread+0x1cc/0x1e8
ret_from_fork+0x10/0x18
-> #1 (slab_mutex){+.+.}:
lock_acquire+0x31c/0x360
__mutex_lock_common+0x16c/0xf78
mutex_lock_nested+0x40/0x50
memcg_create_kmem_cache+0x38/0x16c
memcg_kmem_cache_create_func+0x3c/0x70
process_one_work+0x4f4/0x950
worker_thread+0x390/0x4bc
kthread+0x1cc/0x1e8
ret_from_fork+0x10/0x18
-> #0 (mem_hotplug_lock.rw_sem){++++}:
validate_chain+0xd10/0x2bcc
__lock_acquire+0x7f4/0xb8c
lock_acquire+0x31c/0x360
get_online_mems+0x54/0x150
show_slab_objects+0x94/0x3a8
total_objects_show+0x28/0x34
slab_attr_show+0x38/0x54
sysfs_kf_seq_show+0x198/0x2d4
kernfs_seq_show+0xa4/0xcc
seq_read+0x30c/0x8a8
kernfs_fop_read+0xa8/0x314
__vfs_read+0x88/0x20c
vfs_read+0xd8/0x10c
ksys_read+0xb0/0x120
__arm64_sys_read+0x54/0x88
el0_svc_handler+0x170/0x240
el0_svc+0x8/0xc
other info that might help us debug this:
Chain exists of:
mem_hotplug_lock.rw_sem --> slab_mutex --> kn->count#45
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(kn->count#45);
lock(slab_mutex);
lock(kn->count#45);
lock(mem_hotplug_lock.rw_sem);
*** DEADLOCK ***
3 locks held by cat/5224:
#0: 9eff00095b14b2a0 (&p->lock){+.+.}, at: seq_read+0x4c/0x8a8
#1: 0eff008997041480 (&of->mutex){+.+.}, at: kernfs_seq_start+0x34/0xf0
#2: b8ff009693eee398 (kn->count#45){++++}, at:
kernfs_seq_start+0x44/0xf0
stack backtrace:
Call trace:
dump_backtrace+0x0/0x248
show_stack+0x20/0x2c
dump_stack+0xd0/0x140
print_circular_bug+0x368/0x380
check_noncircular+0x248/0x250
validate_chain+0xd10/0x2bcc
__lock_acquire+0x7f4/0xb8c
lock_acquire+0x31c/0x360
get_online_mems+0x54/0x150
show_slab_objects+0x94/0x3a8
total_objects_show+0x28/0x34
slab_attr_show+0x38/0x54
sysfs_kf_seq_show+0x198/0x2d4
kernfs_seq_show+0xa4/0xcc
seq_read+0x30c/0x8a8
kernfs_fop_read+0xa8/0x314
__vfs_read+0x88/0x20c
vfs_read+0xd8/0x10c
ksys_read+0xb0/0x120
__arm64_sys_read+0x54/0x88
el0_svc_handler+0x170/0x240
el0_svc+0x8/0xc
I think it is important to mention that this doesn't expose the
show_slab_objects to use-after-free. There is only a single path that
might really race here and that is the slab hotplug notifier callback
__kmem_cache_shrink (via slab_mem_going_offline_callback) but that path
doesn't really destroy kmem_cache_node data structures.
[1] http://lkml.iu.edu/hypermail/linux/kernel/1101.0/02850.html
[akpm@linux-foundation.org: add comment explaining why we don't need mem_hotplug_lock]
Link: http://lkml.kernel.org/r/1570192309-10132-1-git-send-email-cai@lca.pw
Fixes: 01fb58bcba63 ("slab: remove synchronous synchronize_sched() from memcg cache deactivation path")
Fixes: 03afc0e25f7f ("slab: get_online_mems for kmem_cache_{create,destroy,shrink}")
Signed-off-by: Qian Cai <cai@lca.pw>
Acked-by: Michal Hocko <mhocko@suse.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: Tejun Heo <tj@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
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commit 96c804a6ae8c59a9092b3d5dd581198472063184 upstream.
We should check for pfn_to_online_page() to not access uninitialized
memmaps. Reshuffle the code so we don't have to duplicate the error
message.
Link: http://lkml.kernel.org/r/20191009142435.3975-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Fixes: f1dd2cd13c4b ("mm, memory_hotplug: do not associate hotadded memory to zones until online") [visible after d0dc12e86b319]
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: <stable@vger.kernel.org> [4.13+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
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commit 518a86713078168acd67cf50bc0b45d54b4cce6c upstream.
The "mode" and "level" variables are enums and in this context GCC will
treat them as unsigned ints so the error handling is never triggered.
I also removed the bogus initializer because it isn't required any more
and it's sort of confusing.
[akpm@linux-foundation.org: reduce implicit and explicit typecasting]
[akpm@linux-foundation.org: fix return value, add comment, per Matthew]
Link: http://lkml.kernel.org/r/20190925110449.GO3264@mwanda
Fixes: 3cadfa2b9497 ("mm/vmpressure.c: convert to use match_string() helper")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: Matthew Wilcox <willy@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Enrico Weigelt <info@metux.net>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
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commit 234fdce892f905cbc2674349a9eb4873e288e5b3 upstream.
On architectures like s390, arch_free_page() could mark the page unused
(set_page_unused()) and any access later would trigger a kernel panic.
Fix it by moving arch_free_page() after all possible accessing calls.
Hardware name: IBM 2964 N96 400 (z/VM 6.4.0)
Krnl PSW : 0404e00180000000 0000000026c2b96e (__free_pages_ok+0x34e/0x5d8)
R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3
Krnl GPRS: 0000000088d43af7 0000000000484000 000000000000007c 000000000000000f
000003d080012100 000003d080013fc0 0000000000000000 0000000000100000
00000000275cca48 0000000000000100 0000000000000008 000003d080010000
00000000000001d0 000003d000000000 0000000026c2b78a 000000002717fdb0
Krnl Code: 0000000026c2b95c: ec1100b30659 risbgn %r1,%r1,0,179,6
0000000026c2b962: e32014000036 pfd 2,1024(%r1)
#0000000026c2b968: d7ff10001000 xc 0(256,%r1),0(%r1)
>0000000026c2b96e: 41101100 la %r1,256(%r1)
0000000026c2b972: a737fff8 brctg %r3,26c2b962
0000000026c2b976: d7ff10001000 xc 0(256,%r1),0(%r1)
0000000026c2b97c: e31003400004 lg %r1,832
0000000026c2b982: ebff1430016a asi 5168(%r1),-1
Call Trace:
__free_pages_ok+0x16a/0x5d8)
memblock_free_all+0x206/0x290
mem_init+0x58/0x120
start_kernel+0x2b0/0x570
startup_continue+0x6a/0xc0
INFO: lockdep is turned off.
Last Breaking-Event-Address:
__free_pages_ok+0x372/0x5d8
Kernel panic - not syncing: Fatal exception: panic_on_oops
00: HCPGIR450W CP entered; disabled wait PSW 00020001 80000000 00000000 26A2379C
In the past, only kernel_poison_pages() would trigger this but it needs
"page_poison=on" kernel cmdline, and I suspect nobody tested that on
s390. Recently, kernel_init_free_pages() (commit 6471384af2a6 ("mm:
security: introduce init_on_alloc=1 and init_on_free=1 boot options"))
was added and could trigger this as well.
[akpm@linux-foundation.org: add comment]
Link: http://lkml.kernel.org/r/1569613623-16820-1-git-send-email-cai@lca.pw
Fixes: 8823b1dbc05f ("mm/page_poison.c: enable PAGE_POISONING as a separate option")
Fixes: 6471384af2a6 ("mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options")
Signed-off-by: Qian Cai <cai@lca.pw>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: <stable@vger.kernel.org> [5.3+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
|
|
commit 5b6807de11445c05b537df8324f5d7ab1c2782f9 upstream.
There's a really hard to reproduce race in z3fold between z3fold_free()
and z3fold_reclaim_page(). z3fold_reclaim_page() can claim the page
after z3fold_free() has checked if the page was claimed and
z3fold_free() will then schedule this page for compaction which may in
turn lead to random page faults (since that page would have been
reclaimed by then).
Fix that by claiming page in the beginning of z3fold_free() and not
forgetting to clear the claim in the end.
[vitalywool@gmail.com: v2]
Link: http://lkml.kernel.org/r/20190928113456.152742cf@bigdell
Link: http://lkml.kernel.org/r/20190926104844.4f0c6efa1366b8f5741eaba9@gmail.com
Signed-off-by: Vitaly Wool <vitalywool@gmail.com>
Reported-by: Markus Linnala <markus.linnala@gmail.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Henry Burns <henrywolfeburns@gmail.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Markus Linnala <markus.linnala@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>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
|
|
commit 314eed30ede02fa925990f535652254b5bad6b65 upstream.
When running on a system with >512MB RAM with a 32-bit kernel built with:
CONFIG_DEBUG_VIRTUAL=y
CONFIG_HIGHMEM=y
CONFIG_HARDENED_USERCOPY=y
all execve()s will fail due to argv copying into kmap()ed pages, and on
usercopy checking the calls ultimately of virt_to_page() will be looking
for "bad" kmap (highmem) pointers due to CONFIG_DEBUG_VIRTUAL=y:
------------[ cut here ]------------
kernel BUG at ../arch/x86/mm/physaddr.c:83!
invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.3.0-rc8 #6
Hardware name: Dell Inc. Inspiron 1318/0C236D, BIOS A04 01/15/2009
EIP: __phys_addr+0xaf/0x100
...
Call Trace:
__check_object_size+0xaf/0x3c0
? __might_sleep+0x80/0xa0
copy_strings+0x1c2/0x370
copy_strings_kernel+0x2b/0x40
__do_execve_file+0x4ca/0x810
? kmem_cache_alloc+0x1c7/0x370
do_execve+0x1b/0x20
...
The check is from arch/x86/mm/physaddr.c:
VIRTUAL_BUG_ON((phys_addr >> PAGE_SHIFT) > max_low_pfn);
Due to the kmap() in fs/exec.c:
kaddr = kmap(kmapped_page);
...
if (copy_from_user(kaddr+offset, str, bytes_to_copy)) ...
Now we can fetch the correct page to avoid the pfn check. In both cases,
hardened usercopy will need to walk the page-span checker (if enabled)
to do sanity checking.
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Fixes: f5509cc18daa ("mm: Hardened usercopy")
Cc: Matthew Wilcox <willy@infradead.org>
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/201909171056.7F2FFD17@keescook
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
|
|
commit 692fe62433d4ca47605b39f7c416efd6679ba694 upstream.
Currently handling of MADV_WILLNEED hint calls directly into readahead
code. Handle it by calling vfs_fadvise() instead so that filesystem can
use its ->fadvise() callback to acquire necessary locks or otherwise
prepare for the request.
Suggested-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Boaz Harrosh <boazh@netapp.com>
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit cf1ea0592dbf109e7e7935b7d5b1a47a1ba04174 upstream.
Filesystems will need to call this function from their fadvise handlers.
CC: stable@vger.kernel.org
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit e55d9d9bfb69405bd7615c0f8d229d8fafb3e9b8 upstream.
Thomas has noticed the following NULL ptr dereference when using cgroup
v1 kmem limit:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
PGD 0
P4D 0
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 3 PID: 16923 Comm: gtk-update-icon Not tainted 4.19.51 #42
Hardware name: Gigabyte Technology Co., Ltd. Z97X-Gaming G1/Z97X-Gaming G1, BIOS F9 07/31/2015
RIP: 0010:create_empty_buffers+0x24/0x100
Code: cd 0f 1f 44 00 00 0f 1f 44 00 00 41 54 49 89 d4 ba 01 00 00 00 55 53 48 89 fb e8 97 fe ff ff 48 89 c5 48 89 c2 eb 03 48 89 ca <48> 8b 4a 08 4c 09 22 48 85 c9 75 f1 48 89 6a 08 48 8b 43 18 48 8d
RSP: 0018:ffff927ac1b37bf8 EFLAGS: 00010286
RAX: 0000000000000000 RBX: fffff2d4429fd740 RCX: 0000000100097149
RDX: 0000000000000000 RSI: 0000000000000082 RDI: ffff9075a99fbe00
RBP: 0000000000000000 R08: fffff2d440949cc8 R09: 00000000000960c0
R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000000
R13: ffff907601f18360 R14: 0000000000002000 R15: 0000000000001000
FS: 00007fb55b288bc0(0000) GS:ffff90761f8c0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000008 CR3: 000000007aebc002 CR4: 00000000001606e0
Call Trace:
create_page_buffers+0x4d/0x60
__block_write_begin_int+0x8e/0x5a0
? ext4_inode_attach_jinode.part.82+0xb0/0xb0
? jbd2__journal_start+0xd7/0x1f0
ext4_da_write_begin+0x112/0x3d0
generic_perform_write+0xf1/0x1b0
? file_update_time+0x70/0x140
__generic_file_write_iter+0x141/0x1a0
ext4_file_write_iter+0xef/0x3b0
__vfs_write+0x17e/0x1e0
vfs_write+0xa5/0x1a0
ksys_write+0x57/0xd0
do_syscall_64+0x55/0x160
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Tetsuo then noticed that this is because the __memcg_kmem_charge_memcg
fails __GFP_NOFAIL charge when the kmem limit is reached. This is a wrong
behavior because nofail allocations are not allowed to fail. Normal
charge path simply forces the charge even if that means to cross the
limit. Kmem accounting should be doing the same.
Link: http://lkml.kernel.org/r/20190906125608.32129-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Thomas Lindroth <thomas.lindroth@gmail.com>
Debugged-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Thomas Lindroth <thomas.lindroth@gmail.com>
Cc: Shakeel Butt <shakeelb@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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit f9c645621a28e37813a1de96d9cbd89cde94a1e4 upstream.
Masoud Sharbiani noticed that commit 29ef680ae7c21110 ("memcg, oom: move
out_of_memory back to the charge path") broke memcg OOM called from
__xfs_filemap_fault() path. It turned out that try_charge() is retrying
forever without making forward progress because mem_cgroup_oom(GFP_NOFS)
cannot invoke the OOM killer due to commit 3da88fb3bacfaa33 ("mm, oom:
move GFP_NOFS check to out_of_memory").
Allowing forced charge due to being unable to invoke memcg OOM killer will
lead to global OOM situation. Also, just returning -ENOMEM will be risky
because OOM path is lost and some paths (e.g. get_user_pages()) will leak
-ENOMEM. Therefore, invoking memcg OOM killer (despite GFP_NOFS) will be
the only choice we can choose for now.
Until 29ef680ae7c21110, we were able to invoke memcg OOM killer when
GFP_KERNEL reclaim failed [1]. But since 29ef680ae7c21110, we need to
invoke memcg OOM killer when GFP_NOFS reclaim failed [2]. Although in the
past we did invoke memcg OOM killer for GFP_NOFS [3], we might get
pre-mature memcg OOM reports due to this patch.
[1]
leaker invoked oom-killer: gfp_mask=0x6200ca(GFP_HIGHUSER_MOVABLE), nodemask=(null), order=0, oom_score_adj=0
CPU: 0 PID: 2746 Comm: leaker Not tainted 4.18.0+ #19
Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 04/13/2018
Call Trace:
dump_stack+0x63/0x88
dump_header+0x67/0x27a
? mem_cgroup_scan_tasks+0x91/0xf0
oom_kill_process+0x210/0x410
out_of_memory+0x10a/0x2c0
mem_cgroup_out_of_memory+0x46/0x80
mem_cgroup_oom_synchronize+0x2e4/0x310
? high_work_func+0x20/0x20
pagefault_out_of_memory+0x31/0x76
mm_fault_error+0x55/0x115
? handle_mm_fault+0xfd/0x220
__do_page_fault+0x433/0x4e0
do_page_fault+0x22/0x30
? page_fault+0x8/0x30
page_fault+0x1e/0x30
RIP: 0033:0x4009f0
Code: 03 00 00 00 e8 71 fd ff ff 48 83 f8 ff 49 89 c6 74 74 48 89 c6 bf c0 0c 40 00 31 c0 e8 69 fd ff ff 45 85 ff 7e 21 31 c9 66 90 <41> 0f be 14 0e 01 d3 f7 c1 ff 0f 00 00 75 05 41 c6 04 0e 2a 48 83
RSP: 002b:00007ffe29ae96f0 EFLAGS: 00010206
RAX: 000000000000001b RBX: 0000000000000000 RCX: 0000000001ce1000
RDX: 0000000000000000 RSI: 000000007fffffe5 RDI: 0000000000000000
RBP: 000000000000000c R08: 0000000000000000 R09: 00007f94be09220d
R10: 0000000000000002 R11: 0000000000000246 R12: 00000000000186a0
R13: 0000000000000003 R14: 00007f949d845000 R15: 0000000002800000
Task in /leaker killed as a result of limit of /leaker
memory: usage 524288kB, limit 524288kB, failcnt 158965
memory+swap: usage 0kB, limit 9007199254740988kB, failcnt 0
kmem: usage 2016kB, limit 9007199254740988kB, failcnt 0
Memory cgroup stats for /leaker: cache:844KB rss:521136KB rss_huge:0KB shmem:0KB mapped_file:0KB dirty:132KB writeback:0KB inactive_anon:0KB active_anon:521224KB inactive_file:1012KB active_file:8KB unevictable:0KB
Memory cgroup out of memory: Kill process 2746 (leaker) score 998 or sacrifice child
Killed process 2746 (leaker) total-vm:536704kB, anon-rss:521176kB, file-rss:1208kB, shmem-rss:0kB
oom_reaper: reaped process 2746 (leaker), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
[2]
leaker invoked oom-killer: gfp_mask=0x600040(GFP_NOFS), nodemask=(null), order=0, oom_score_adj=0
CPU: 1 PID: 2746 Comm: leaker Not tainted 4.18.0+ #20
Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 04/13/2018
Call Trace:
dump_stack+0x63/0x88
dump_header+0x67/0x27a
? mem_cgroup_scan_tasks+0x91/0xf0
oom_kill_process+0x210/0x410
out_of_memory+0x109/0x2d0
mem_cgroup_out_of_memory+0x46/0x80
try_charge+0x58d/0x650
? __radix_tree_replace+0x81/0x100
mem_cgroup_try_charge+0x7a/0x100
__add_to_page_cache_locked+0x92/0x180
add_to_page_cache_lru+0x4d/0xf0
iomap_readpages_actor+0xde/0x1b0
? iomap_zero_range_actor+0x1d0/0x1d0
iomap_apply+0xaf/0x130
iomap_readpages+0x9f/0x150
? iomap_zero_range_actor+0x1d0/0x1d0
xfs_vm_readpages+0x18/0x20 [xfs]
read_pages+0x60/0x140
__do_page_cache_readahead+0x193/0x1b0
ondemand_readahead+0x16d/0x2c0
page_cache_async_readahead+0x9a/0xd0
filemap_fault+0x403/0x620
? alloc_set_pte+0x12c/0x540
? _cond_resched+0x14/0x30
__xfs_filemap_fault+0x66/0x180 [xfs]
xfs_filemap_fault+0x27/0x30 [xfs]
__do_fault+0x19/0x40
__handle_mm_fault+0x8e8/0xb60
handle_mm_fault+0xfd/0x220
__do_page_fault+0x238/0x4e0
do_page_fault+0x22/0x30
? page_fault+0x8/0x30
page_fault+0x1e/0x30
RIP: 0033:0x4009f0
Code: 03 00 00 00 e8 71 fd ff ff 48 83 f8 ff 49 89 c6 74 74 48 89 c6 bf c0 0c 40 00 31 c0 e8 69 fd ff ff 45 85 ff 7e 21 31 c9 66 90 <41> 0f be 14 0e 01 d3 f7 c1 ff 0f 00 00 75 05 41 c6 04 0e 2a 48 83
RSP: 002b:00007ffda45c9290 EFLAGS: 00010206
RAX: 000000000000001b RBX: 0000000000000000 RCX: 0000000001a1e000
RDX: 0000000000000000 RSI: 000000007fffffe5 RDI: 0000000000000000
RBP: 000000000000000c R08: 0000000000000000 R09: 00007f6d061ff20d
R10: 0000000000000002 R11: 0000000000000246 R12: 00000000000186a0
R13: 0000000000000003 R14: 00007f6ce59b2000 R15: 0000000002800000
Task in /leaker killed as a result of limit of /leaker
memory: usage 524288kB, limit 524288kB, failcnt 7221
memory+swap: usage 0kB, limit 9007199254740988kB, failcnt 0
kmem: usage 1944kB, limit 9007199254740988kB, failcnt 0
Memory cgroup stats for /leaker: cache:3632KB rss:518232KB rss_huge:0KB shmem:0KB mapped_file:0KB dirty:0KB writeback:0KB inactive_anon:0KB active_anon:518408KB inactive_file:3908KB active_file:12KB unevictable:0KB
Memory cgroup out of memory: Kill process 2746 (leaker) score 992 or sacrifice child
Killed process 2746 (leaker) total-vm:536704kB, anon-rss:518264kB, file-rss:1188kB, shmem-rss:0kB
oom_reaper: reaped process 2746 (leaker), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
[3]
leaker invoked oom-killer: gfp_mask=0x50, order=0, oom_score_adj=0
leaker cpuset=/ mems_allowed=0
CPU: 1 PID: 3206 Comm: leaker Not tainted 3.10.0-957.27.2.el7.x86_64 #1
Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 04/13/2018
Call Trace:
[<ffffffffaf364147>] dump_stack+0x19/0x1b
[<ffffffffaf35eb6a>] dump_header+0x90/0x229
[<ffffffffaedbb456>] ? find_lock_task_mm+0x56/0xc0
[<ffffffffaee32a38>] ? try_get_mem_cgroup_from_mm+0x28/0x60
[<ffffffffaedbb904>] oom_kill_process+0x254/0x3d0
[<ffffffffaee36c36>] mem_cgroup_oom_synchronize+0x546/0x570
[<ffffffffaee360b0>] ? mem_cgroup_charge_common+0xc0/0xc0
[<ffffffffaedbc194>] pagefault_out_of_memory+0x14/0x90
[<ffffffffaf35d072>] mm_fault_error+0x6a/0x157
[<ffffffffaf3717c8>] __do_page_fault+0x3c8/0x4f0
[<ffffffffaf371925>] do_page_fault+0x35/0x90
[<ffffffffaf36d768>] page_fault+0x28/0x30
Task in /leaker killed as a result of limit of /leaker
memory: usage 524288kB, limit 524288kB, failcnt 20628
memory+swap: usage 524288kB, limit 9007199254740988kB, failcnt 0
kmem: usage 0kB, limit 9007199254740988kB, failcnt 0
Memory cgroup stats for /leaker: cache:840KB rss:523448KB rss_huge:0KB mapped_file:0KB swap:0KB inactive_anon:0KB active_anon:523448KB inactive_file:464KB active_file:376KB unevictable:0KB
Memory cgroup out of memory: Kill process 3206 (leaker) score 970 or sacrifice child
Killed process 3206 (leaker) total-vm:536692kB, anon-rss:523304kB, file-rss:412kB, shmem-rss:0kB
Bisected by Masoud Sharbiani.
Link: http://lkml.kernel.org/r/cbe54ed1-b6ba-a056-8899-2dc42526371d@i-love.sakura.ne.jp
Fixes: 3da88fb3bacfaa33 ("mm, oom: move GFP_NOFS check to out_of_memory") [necessary after 29ef680ae7c21110]
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: Masoud Sharbiani <msharbiani@apple.com>
Tested-by: Masoud Sharbiani <msharbiani@apple.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: <stable@vger.kernel.org> [4.19+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit a94b525241c0fff3598809131d7cfcfe1d572d8c upstream.
total_{migrate,free}_scanned will be added to COMPACTMIGRATE_SCANNED and
COMPACTFREE_SCANNED in compact_zone(). We should clear them before
scanning a new zone. In the proc triggered compaction, we forgot clearing
them.
[laoar.shao@gmail.com: introduce a helper compact_zone_counters_init()]
Link: http://lkml.kernel.org/r/1563869295-25748-1-git-send-email-laoar.shao@gmail.com
[akpm@linux-foundation.org: expand compact_zone_counters_init() into its single callsite, per mhocko]
[vbabka@suse.cz: squash compact_zone() list_head init as well]
Link: http://lkml.kernel.org/r/1fb6f7da-f776-9e42-22f8-bbb79b030b98@suse.cz
[akpm@linux-foundation.org: kcompactd_do_work(): avoid unnecessary initialization of cc.zone]
Link: http://lkml.kernel.org/r/1563789275-9639-1-git-send-email-laoar.shao@gmail.com
Fixes: 7f354a548d1c ("mm, compaction: add vmstats for kcompactd work")
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Yafang Shao <shaoyafang@didiglobal.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 63398413c00c7836ea87a1fa205c91d2199b25cf upstream.
Currently there is a leak in init_z3fold_page() -- it allocates handles
from kmem cache even for headless pages, but then they are never used and
never freed, so eventually kmem cache may get exhausted. This patch
provides a fix for that.
Link: http://lkml.kernel.org/r/20190917185352.44cf285d3ebd9e64548de5de@gmail.com
Signed-off-by: Vitaly Wool <vitalywool@gmail.com>
Reported-by: Markus Linnala <markus.linnala@gmail.com>
Tested-by: Markus Linnala <markus.linnala@gmail.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Henry Burns <henrywolfeburns@gmail.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Vlastimil Babka <vbabka@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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 3f9d2b5766aea06042630ac60b7316fd0cebf06f upstream.
z3fold_page_reclaim()'s retry mechanism is broken: on a second iteration
it will have zhdr from the first one so that zhdr is no longer in line
with struct page. That leads to crashes when the system is stressed.
Fix that by moving zhdr assignment up.
While at it, protect against using already freed handles by using own
local slots structure in z3fold_page_reclaim().
Link: http://lkml.kernel.org/r/20190908162919.830388dc7404d1e2c80f4095@gmail.com
Signed-off-by: Vitaly Wool <vitalywool@gmail.com>
Reported-by: Markus Linnala <markus.linnala@gmail.com>
Reported-by: Chris Murphy <bugzilla@colorremedies.com>
Reported-by: Agustin Dall'Alba <agustin@dallalba.com.ar>
Cc: "Maciej S. Szmigiero" <mail@maciej.szmigiero.name>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Henry Burns <henrywolfeburns@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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 6e73fd25e2c7510b7dfadbaf701f31d4bff9c75b upstream.
With the original commit applied, z3fold_zpool_destroy() may get blocked
on wait_event() for indefinite time. Revert this commit for the time
being to get rid of this problem since the issue the original commit
addresses is less severe.
Link: http://lkml.kernel.org/r/20190910123142.7a9c8d2de4d0acbc0977c602@gmail.com
Fixes: d776aaa9895eb6eb77 ("mm/z3fold.c: fix race between migration and destruction")
Reported-by: Agustín Dall'Alba <agustin@dallalba.com.ar>
Signed-off-by: Vitaly Wool <vitalywool@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Jonathan Adams <jwadams@google.com>
Cc: Henry Burns <henrywolfeburns@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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 14108b9131a47ff18a3c640f583eb2d625c75c0d upstream.
Fix lock/unlock imbalance by unlocking *zhdr* before return.
Addresses Coverity ID 1452811 ("Missing unlock")
Link: http://lkml.kernel.org/r/20190826030634.GA4379@embeddedor
Fixes: d776aaa9895e ("mm/z3fold.c: fix race between migration and destruction")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Henry Burns <henrywolfeburns@gmail.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit be03074c9af25d06cf8e9ebddfcd284c0bf7f947 upstream.
z3fold_page_migrate() will never succeed because it attempts to acquire
a lock that has already been taken by migrate.c in __unmap_and_move().
__unmap_and_move() migrate.c
trylock_page(oldpage)
move_to_new_page(oldpage_newpage)
a_ops->migrate_page(oldpage, newpage)
z3fold_page_migrate(oldpage, newpage)
trylock_page(oldpage)
Link: http://lkml.kernel.org/r/20190710213238.91835-1-henryburns@google.com
Fixes: 1f862989b04a ("mm/z3fold.c: support page migration")
Signed-off-by: Henry Burns <henryburns@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Vitaly Vul <vitaly.vul@sony.com>
Cc: Jonathan Adams <jwadams@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Snild Dolkow <snild@sony.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 6c1c280805ded72eceb2afc1a0d431b256608554 upstream.
Instead of using raw_cpu_read() use per_cpu() to read the actual data of
the corresponding cpu otherwise we will be reading the data of the
current cpu for the number of online CPUs.
Link: http://lkml.kernel.org/r/20190829203110.129263-1-shakeelb@google.com
Fixes: bb65f89b7d3d ("mm: memcontrol: flush percpu vmevents before releasing memcg")
Fixes: c350a99ea2b1 ("mm: memcontrol: flush percpu vmstats before releasing memcg")
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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with the hierarchical ones"
commit b4c46484dc3fa3721d68fdfae85c1d7b1f6b5472 upstream.
Commit 766a4c19d880 ("mm/memcontrol.c: keep local VM counters in sync
with the hierarchical ones") effectively decreased the precision of
per-memcg vmstats_local and per-memcg-per-node lruvec percpu counters.
That's good for displaying in memory.stat, but brings a serious
regression into the reclaim process.
One issue I've discovered and debugged is the following:
lruvec_lru_size() can return 0 instead of the actual number of pages in
the lru list, preventing the kernel to reclaim last remaining pages.
Result is yet another dying memory cgroups flooding. The opposite is
also happening: scanning an empty lru list is the waste of cpu time.
Also, inactive_list_is_low() can return incorrect values, preventing the
active lru from being scanned and freed. It can fail both because the
size of active and inactive lists are inaccurate, and because the number
of workingset refaults isn't precise. In other words, the result is
pretty random.
I'm not sure, if using the approximate number of slab pages in
count_shadow_number() is acceptable, but issues described above are
enough to partially revert the patch.
Let's keep per-memcg vmstat_local batched (they are only used for
displaying stats to the userspace), but keep lruvec stats precise. This
change fixes the dead memcg flooding on my setup.
Link: http://lkml.kernel.org/r/20190817004726.2530670-1-guro@fb.com
Fixes: 766a4c19d880 ("mm/memcontrol.c: keep local VM counters in sync with the hierarchical ones")
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 441e254cd40dc03beec3c650ce6ce6074bc6517f upstream.
Fixes: 701d678599d0c1 ("mm/zsmalloc.c: fix race condition in zs_destroy_pool")
Link: http://lkml.kernel.org/r/201908251039.5oSbEEUT%25lkp@intel.com
Reported-by: kbuild test robot <lkp@intel.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Henry Burns <henrywolfeburns@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Jonathan Adams <jwadams@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 00fb24a42a68b1ee0f6495993fe1be7124433dfb upstream.
The code like this:
ptr = kmalloc(size, GFP_KERNEL);
page = virt_to_page(ptr);
offset = offset_in_page(ptr);
kfree(page_address(page) + offset);
may produce false-positive invalid-free reports on the kernel with
CONFIG_KASAN_SW_TAGS=y.
In the example above we lose the original tag assigned to 'ptr', so
kfree() gets the pointer with 0xFF tag. In kfree() we check that 0xFF
tag is different from the tag in shadow hence print false report.
Instead of just comparing tags, do the following:
1) Check that shadow doesn't contain KASAN_TAG_INVALID. Otherwise it's
double-free and it doesn't matter what tag the pointer have.
2) If pointer tag is different from 0xFF, make sure that tag in the
shadow is the same as in the pointer.
Link: http://lkml.kernel.org/r/20190819172540.19581-1-aryabinin@virtuozzo.com
Fixes: 7f94ffbc4c6a ("kasan: add hooks implementation for tag-based mode")
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reported-by: Walter Wu <walter-zh.wu@mediatek.com>
Reported-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 701d678599d0c1623aaf4139c03eea260a75b027 upstream.
In zs_destroy_pool() we call flush_work(&pool->free_work). However, we
have no guarantee that migration isn't happening in the background at
that time.
Since migration can't directly free pages, it relies on free_work being
scheduled to free the pages. But there's nothing preventing an
in-progress migrate from queuing the work *after*
zs_unregister_migration() has called flush_work(). Which would mean
pages still pointing at the inode when we free it.
Since we know at destroy time all objects should be free, no new
migrations can come in (since zs_page_isolate() fails for fully-free
zspages). This means it is sufficient to track a "# isolated zspages"
count by class, and have the destroy logic ensure all such pages have
drained before proceeding. Keeping that state under the class spinlock
keeps the logic straightforward.
In this case a memory leak could lead to an eventual crash if compaction
hits the leaked page. This crash would only occur if people are
changing their zswap backend at runtime (which eventually starts
destruction).
Link: http://lkml.kernel.org/r/20190809181751.219326-2-henryburns@google.com
Fixes: 48b4800a1c6a ("zsmalloc: page migration support")
Signed-off-by: Henry Burns <henryburns@google.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Henry Burns <henrywolfeburns@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Jonathan Adams <jwadams@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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 1a87aa03597efa9641e92875b883c94c7f872ccb upstream.
In zs_page_migrate() we call putback_zspage() after we have finished
migrating all pages in this zspage. However, the return value is
ignored. If a zs_free() races in between zs_page_isolate() and
zs_page_migrate(), freeing the last object in the zspage,
putback_zspage() will leave the page in ZS_EMPTY for potentially an
unbounded amount of time.
To fix this, we need to do the same thing as zs_page_putback() does:
schedule free_work to occur.
To avoid duplicated code, move the sequence to a new
putback_zspage_deferred() function which both zs_page_migrate() and
zs_page_putback() call.
Link: http://lkml.kernel.org/r/20190809181751.219326-1-henryburns@google.com
Fixes: 48b4800a1c6a ("zsmalloc: page migration support")
Signed-off-by: Henry Burns <henryburns@google.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Henry Burns <henrywolfeburns@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Jonathan Adams <jwadams@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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit f7da677bc6e72033f0981b9d58b5c5d409fa641e upstream.
THP splitting path is missing the split_page_owner() call that
split_page() has.
As a result, split THP pages are wrongly reported in the page_owner file
as order-9 pages. Furthermore when the former head page is freed, the
remaining former tail pages are not listed in the page_owner file at
all. This patch fixes that by adding the split_page_owner() call into
__split_huge_page().
Link: http://lkml.kernel.org/r/20190820131828.22684-2-vbabka@suse.cz
Fixes: a9627bc5e34e ("mm/page_owner: introduce split_page_owner and replace manual handling")
Reported-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit bb65f89b7d3d305c14951f49860711fbcae70692 upstream.
Similar to vmstats, percpu caching of local vmevents leads to an
accumulation of errors on non-leaf levels. This happens because some
leftovers may remain in percpu caches, so that they are never propagated
up by the cgroup tree and just disappear into nonexistence with on
releasing of the memory cgroup.
To fix this issue let's accumulate and propagate percpu vmevents values
before releasing the memory cgroup similar to what we're doing with
vmstats.
Since on cpu hotplug we do flush percpu vmstats anyway, we can iterate
only over online cpus.
Link: http://lkml.kernel.org/r/20190819202338.363363-4-guro@fb.com
Fixes: 42a300353577 ("mm: memcontrol: fix recursive statistics correctness & scalabilty")
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit c350a99ea2b1b666c28948d74ab46c16913c28a7 upstream.
Percpu caching of local vmstats with the conditional propagation by the
cgroup tree leads to an accumulation of errors on non-leaf levels.
Let's imagine two nested memory cgroups A and A/B. Say, a process
belonging to A/B allocates 100 pagecache pages on the CPU 0. The percpu
cache will spill 3 times, so that 32*3=96 pages will be accounted to A/B
and A atomic vmstat counters, 4 pages will remain in the percpu cache.
Imagine A/B is nearby memory.max, so that every following allocation
triggers a direct reclaim on the local CPU. Say, each such attempt will
free 16 pages on a new cpu. That means every percpu cache will have -16
pages, except the first one, which will have 4 - 16 = -12. A/B and A
atomic counters will not be touched at all.
Now a user removes A/B. All percpu caches are freed and corresponding
vmstat numbers are forgotten. A has 96 pages more than expected.
As memory cgroups are created and destroyed, errors do accumulate. Even
1-2 pages differences can accumulate into large numbers.
To fix this issue let's accumulate and propagate percpu vmstat values
before releasing the memory cgroup. At this point these numbers are
stable and cannot be changed.
Since on cpu hotplug we do flush percpu vmstats anyway, we can iterate
only over online cpus.
Link: http://lkml.kernel.org/r/20190819202338.363363-2-guro@fb.com
Fixes: 42a300353577 ("mm: memcontrol: fix recursive statistics correctness & scalabilty")
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit cd961038381f392b364a7c4a040f4576ca415b1a upstream.
After commit 907ec5fca3dc ("mm: zero remaining unavailable struct
pages"), struct page of reserved memory is zeroed. This causes
page->flags to be 0 and fixes issues related to reading
/proc/kpageflags, for example, of reserved memory.
The VM_BUG_ON() in move_freepages_block(), however, assumes that
page_zone() is meaningful even for reserved memory. That assumption is
no longer true after the aforementioned commit.
There's no reason why move_freepages_block() should be testing the
legitimacy of page_zone() for reserved memory; its scope is limited only
to pages on the zone's freelist.
Note that pfn_valid() can be true for reserved memory: there is a
backing struct page. The check for page_to_nid(page) is also buggy but
reserved memory normally only appears on node 0 so the zeroing doesn't
affect this.
Move the debug checks to after verifying PageBuddy is true. This
isolates the scope of the checks to only be for buddy pages which are on
the zone's freelist which move_freepages_block() is operating on. In
this case, an incorrect node or zone is a bug worthy of being warned
about (and the examination of struct page is acceptable bcause this
memory is not reserved).
Why does move_freepages_block() gets called on reserved memory? It's
simply math after finding a valid free page from the per-zone free area
to use as fallback. We find the beginning and end of the pageblock of
the valid page and that can bring us into memory that was reserved per
the e820. pfn_valid() is still true (it's backed by a struct page), but
since it's zero'd we shouldn't make any inferences here about comparing
its node or zone. The current node check just happens to succeed most
of the time by luck because reserved memory typically appears on node 0.
The fix here is to validate that we actually have buddy pages before
testing if there's any type of zone or node strangeness going on.
We noticed it almost immediately after bringing 907ec5fca3dc in on
CONFIG_DEBUG_VM builds. It depends on finding specific free pages in
the per-zone free area where the math in move_freepages() will bring the
start or end pfn into reserved memory and wanting to claim that entire
pageblock as a new migratetype. So the path will be rare, require
CONFIG_DEBUG_VM, and require fallback to a different migratetype.
Some struct pages were already zeroed from reserve pages before
907ec5fca3c so it theoretically could trigger before this commit. I
think it's rare enough under a config option that most people don't run
that others may not have noticed. I wouldn't argue against a stable tag
and the backport should be easy enough, but probably wouldn't single out
a commit that this is fixing.
Mel said:
: The overhead of the debugging check is higher with this patch although
: it'll only affect debug builds and the path is not particularly hot.
: If this was a concern, I think it would be reasonable to simply remove
: the debugging check as the zone boundaries are checked in
: move_freepages_block and we never expect a zone/node to be smaller than
: a pageblock and stuck in the middle of another zone.
Link: http://lkml.kernel.org/r/alpine.DEB.2.21.1908122036560.10779@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Tatashin <pavel.tatashin@microsoft.com>
Cc: Vlastimil Babka <vbabka@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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit d776aaa9895eb6eb770908e899cb7f5bd5025b3c upstream.
In z3fold_destroy_pool() we call destroy_workqueue(&pool->compact_wq).
However, we have no guarantee that migration isn't happening in the
background at that time.
Migration directly calls queue_work_on(pool->compact_wq), if destruction
wins that race we are using a destroyed workqueue.
Link: http://lkml.kernel.org/r/20190809213828.202833-1-henryburns@google.com
Signed-off-by: Henry Burns <henryburns@google.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Jonathan Adams <jwadams@google.com>
Cc: Henry Burns <henrywolfeburns@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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit df9576def004d2cd5beedc00cb6e8901427634b9 ]
When running ltp's oom test with kmemleak enabled, the below warning was
triggerred since kernel detects __GFP_NOFAIL & ~__GFP_DIRECT_RECLAIM is
passed in:
WARNING: CPU: 105 PID: 2138 at mm/page_alloc.c:4608 __alloc_pages_nodemask+0x1c31/0x1d50
Modules linked in: loop dax_pmem dax_pmem_core ip_tables x_tables xfs virtio_net net_failover virtio_blk failover ata_generic virtio_pci virtio_ring virtio libata
CPU: 105 PID: 2138 Comm: oom01 Not tainted 5.2.0-next-20190710+ #7
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014
RIP: 0010:__alloc_pages_nodemask+0x1c31/0x1d50
...
kmemleak_alloc+0x4e/0xb0
kmem_cache_alloc+0x2a7/0x3e0
mempool_alloc_slab+0x2d/0x40
mempool_alloc+0x118/0x2b0
bio_alloc_bioset+0x19d/0x350
get_swap_bio+0x80/0x230
__swap_writepage+0x5ff/0xb20
The mempool_alloc_slab() clears __GFP_DIRECT_RECLAIM, however kmemleak
has __GFP_NOFAIL set all the time due to d9570ee3bd1d4f2 ("kmemleak:
allow to coexist with fault injection"). But, it doesn't make any sense
to have __GFP_NOFAIL and ~__GFP_DIRECT_RECLAIM specified at the same
time.
According to the discussion on the mailing list, the commit should be
reverted for short term solution. Catalin Marinas would follow up with
a better solution for longer term.
The failure rate of kmemleak metadata allocation may increase in some
circumstances, but this should be expected side effect.
Link: http://lkml.kernel.org/r/1563299431-111710-1-git-send-email-yang.shi@linux.alibaba.com
Fixes: d9570ee3bd1d4f2 ("kmemleak: allow to coexist with fault injection")
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 2bcbeaefde2f0384d6ad351c151b1a9fe7791a0a ]
We should not have two different error codes for the same
condition. EAGAIN must be reserved for the FAULT_FLAG_ALLOW_RETRY retry
case and signals to the caller that the mmap_sem has been unlocked.
Use EBUSY for the !valid case so that callers can get the locking right.
Link: https://lore.kernel.org/r/20190724065258.16603-2-hch@lst.de
Tested-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
[jgg: elaborated commit message]
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 28360f398778d7623a5ff8a8e90958c0d925e120 upstream.
Dave Chinner reported a problem pointing a finger at commit 1c30844d2dfe
("mm: reclaim small amounts of memory when an external fragmentation
event occurs").
The report is extensive:
https://lore.kernel.org/linux-mm/20190807091858.2857-1-david@fromorbit.com/
and it's worth recording the most relevant parts (colorful language and
typos included).
When running a simple, steady state 4kB file creation test to
simulate extracting tarballs larger than memory full of small
files into the filesystem, I noticed that once memory fills up
the cache balance goes to hell.
The workload is creating one dirty cached inode for every dirty
page, both of which should require a single IO each to clean and
reclaim, and creation of inodes is throttled by the rate at which
dirty writeback runs at (via balance dirty pages). Hence the ingest
rate of new cached inodes and page cache pages is identical and
steady. As a result, memory reclaim should quickly find a steady
balance between page cache and inode caches.
The moment memory fills, the page cache is reclaimed at a much
faster rate than the inode cache, and evidence suggests that
the inode cache shrinker is not being called when large batches
of pages are being reclaimed. In roughly the same time period
that it takes to fill memory with 50% pages and 50% slab caches,
memory reclaim reduces the page cache down to just dirty pages
and slab caches fill the entirety of memory.
The LRU is largely full of dirty pages, and we're getting spikes
of random writeback from memory reclaim so it's all going to shit.
Behaviour never recovers, the page cache remains pinned at just
dirty pages, and nothing I could tune would make any difference.
vfs_cache_pressure makes no difference - I would set it so high
it should trim the entire inode caches in a single pass, yet it
didn't do anything. It was clear from tracing and live telemetry
that the shrinkers were pretty much not running except when
there was absolutely no memory free at all, and then they did
the minimum necessary to free memory to make progress.
So I went looking at the code, trying to find places where pages
got reclaimed and the shrinkers weren't called. There's only one
- kswapd doing boosted reclaim as per commit 1c30844d2dfe ("mm:
reclaim small amounts of memory when an external fragmentation
event occurs").
The watermark boosting introduced by the commit is triggered in response
to an allocation "fragmentation event". The boosting was not intended
to target THP specifically and triggers even if THP is disabled.
However, with Dave's perfectly reasonable workload, fragmentation events
can be very common given the ratio of slab to page cache allocations so
boosting remains active for long periods of time.
As high-order allocations might use compaction and compaction cannot
move slab pages the decision was made in the commit to special-case
kswapd when watermarks are boosted -- kswapd avoids reclaiming slab as
reclaiming slab does not directly help compaction.
As Dave notes, this decision means that slab can be artificially
protected for long periods of time and messes up the balance with slab
and page caches.
Removing the special casing can still indirectly help avoid
fragmentation by avoiding fragmentation-causing events due to slab
allocation as pages from a slab pageblock will have some slab objects
freed. Furthermore, with the special casing, reclaim behaviour is
unpredictable as kswapd sometimes examines slab and sometimes does not
in a manner that is tricky to tune or analyse.
This patch removes the special casing. The downside is that this is not
a universal performance win. Some benchmarks that depend on the
residency of data when rereading metadata may see a regression when slab
reclaim is restored to its original behaviour. Similarly, some
benchmarks that only read-once or write-once may perform better when
page reclaim is too aggressive. The primary upside is that slab
shrinker is less surprising (arguably more sane but that's a matter of
opinion), behaves consistently regardless of the fragmentation state of
the system and properly obeys VM sysctls.
A fsmark benchmark configuration was constructed similar to what Dave
reported and is codified by the mmtest configuration
config-io-fsmark-small-file-stream. It was evaluated on a 1-socket
machine to avoid dealing with NUMA-related issues and the timing of
reclaim. The storage was an SSD Samsung Evo and a fresh trimmed XFS
filesystem was used for the test data.
This is not an exact replication of Dave's setup. The configuration
scales its parameters depending on the memory size of the SUT to behave
similarly across machines. The parameters mean the first sample
reported by fs_mark is using 50% of RAM which will barely be throttled
and look like a big outlier. Dave used fake NUMA to have multiple
kswapd instances which I didn't replicate. Finally, the number of
iterations differ from Dave's test as the target disk was not large
enough. While not identical, it should be representative.
fsmark
5.3.0-rc3 5.3.0-rc3
vanilla shrinker-v1r1
Min 1-files/sec 4444.80 ( 0.00%) 4765.60 ( 7.22%)
1st-qrtle 1-files/sec 5005.10 ( 0.00%) 5091.70 ( 1.73%)
2nd-qrtle 1-files/sec 4917.80 ( 0.00%) 4855.60 ( -1.26%)
3rd-qrtle 1-files/sec 4667.40 ( 0.00%) 4831.20 ( 3.51%)
Max-1 1-files/sec 11421.50 ( 0.00%) 9999.30 ( -12.45%)
Max-5 1-files/sec 11421.50 ( 0.00%) 9999.30 ( -12.45%)
Max-10 1-files/sec 11421.50 ( 0.00%) 9999.30 ( -12.45%)
Max-90 1-files/sec 4649.60 ( 0.00%) 4780.70 ( 2.82%)
Max-95 1-files/sec 4491.00 ( 0.00%) 4768.20 ( 6.17%)
Max-99 1-files/sec 4491.00 ( 0.00%) 4768.20 ( 6.17%)
Max 1-files/sec 11421.50 ( 0.00%) 9999.30 ( -12.45%)
Hmean 1-files/sec 5004.75 ( 0.00%) 5075.96 ( 1.42%)
Stddev 1-files/sec 1778.70 ( 0.00%) 1369.66 ( 23.00%)
CoeffVar 1-files/sec 33.70 ( 0.00%) 26.05 ( 22.71%)
BHmean-99 1-files/sec 5053.72 ( 0.00%) 5101.52 ( 0.95%)
BHmean-95 1-files/sec 5053.72 ( 0.00%) 5101.52 ( 0.95%)
BHmean-90 1-files/sec 5107.05 ( 0.00%) 5131.41 ( 0.48%)
BHmean-75 1-files/sec 5208.45 ( 0.00%) 5206.68 ( -0.03%)
BHmean-50 1-files/sec 5405.53 ( 0.00%) 5381.62 ( -0.44%)
BHmean-25 1-files/sec 6179.75 ( 0.00%) 6095.14 ( -1.37%)
5.3.0-rc3 5.3.0-rc3
vanillashrinker-v1r1
Duration User 501.82 497.29
Duration System 4401.44 4424.08
Duration Elapsed 8124.76 8358.05
This is showing a slight skew for the max result representing a large
outlier for the 1st, 2nd and 3rd quartile are similar indicating that
the bulk of the results show little difference. Note that an earlier
version of the fsmark configuration showed a regression but that
included more samples taken while memory was still filling.
Note that the elapsed time is higher. Part of this is that the
configuration included time to delete all the test files when the test
completes -- the test automation handles the possibility of testing
fsmark with multiple thread counts. Without the patch, many of these
objects would be memory resident which is part of what the patch is
addressing.
There are other important observations that justify the patch.
1. With the vanilla kernel, the number of dirty pages in the system is
very low for much of the test. With this patch, dirty pages is
generally kept at 10% which matches vm.dirty_background_ratio which
is normal expected historical behaviour.
2. With the vanilla kernel, the ratio of Slab/Pagecache is close to
0.95 for much of the test i.e. Slab is being left alone and
dominating memory consumption. With the patch applied, the ratio
varies between 0.35 and 0.45 with the bulk of the measured ratios
roughly half way between those values. This is a different balance to
what Dave reported but it was at least consistent.
3. Slabs are scanned throughout the entire test with the patch applied.
The vanille kernel has periods with no scan activity and then
relatively massive spikes.
4. Without the patch, kswapd scan rates are very variable. With the
patch, the scan rates remain quite steady.
4. Overall vmstats are closer to normal expectations
5.3.0-rc3 5.3.0-rc3
vanilla shrinker-v1r1
Ops Direct pages scanned 99388.00 328410.00
Ops Kswapd pages scanned 45382917.00 33451026.00
Ops Kswapd pages reclaimed 30869570.00 25239655.00
Ops Direct pages reclaimed 74131.00 5830.00
Ops Kswapd efficiency % 68.02 75.45
Ops Kswapd velocity 5585.75 4002.25
Ops Page reclaim immediate 1179721.00 430927.00
Ops Slabs scanned 62367361.00 73581394.00
Ops Direct inode steals 2103.00 1002.00
Ops Kswapd inode steals 570180.00 5183206.00
o Vanilla kernel is hitting direct reclaim more frequently,
not very much in absolute terms but the fact the patch
reduces it is interesting
o "Page reclaim immediate" in the vanilla kernel indicates
dirty pages are being encountered at the tail of the LRU.
This is generally bad and means in this case that the LRU
is not long enough for dirty pages to be cleaned by the
background flush in time. This is much reduced by the
patch.
o With the patch, kswapd is reclaiming 10 times more slab
pages than with the vanilla kernel. This is indicative
of the watermark boosting over-protecting slab
A more complete set of tests were run that were part of the basis for
introducing boosting and while there are some differences, they are well
within tolerances.
Bottom line, the special casing kswapd to avoid slab behaviour is
unpredictable and can lead to abnormal results for normal workloads.
This patch restores the expected behaviour that slab and page cache is
balanced consistently for a workload with a steady allocation ratio of
slab/pagecache pages. It also means that if there are workloads that
favour the preservation of slab over pagecache that it can be tuned via
vm.vfs_cache_pressure where as the vanilla kernel effectively ignores
the parameter when boosting is active.
Link: http://lkml.kernel.org/r/20190808182946.GM2739@techsingularity.net
Fixes: 1c30844d2dfe ("mm: reclaim small amounts of memory when an external fragmentation event occurs")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: <stable@vger.kernel.org> [5.0+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 951531691c4bcaa59f56a316e018bc2ff1ddf855 upstream.
Currently, when checking to see if accessing n bytes starting at address
"ptr" will cause a wraparound in the memory addresses, the check in
check_bogus_address() adds an extra byte, which is incorrect, as the
range of addresses that will be accessed is [ptr, ptr + (n - 1)].
This can lead to incorrectly detecting a wraparound in the memory
address, when trying to read 4 KB from memory that is mapped to the the
last possible page in the virtual address space, when in fact, accessing
that range of memory would not cause a wraparound to occur.
Use the memory range that will actually be accessed when considering if
accessing a certain amount of bytes will cause the memory address to
wrap around.
Link: http://lkml.kernel.org/r/1564509253-23287-1-git-send-email-isaacm@codeaurora.org
Fixes: f5509cc18daa ("mm: Hardened usercopy")
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>
Co-developed-by: Prasad Sodagudi <psodagud@codeaurora.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Trilok Soni <tsoni@codeaurora.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 54a83d6bcbf8f4700013766b974bf9190d40b689 upstream.
This patch is sent to report an use after free in mem_cgroup_iter()
after merging commit be2657752e9e ("mm: memcg: fix use after free in
mem_cgroup_iter()").
I work with android kernel tree (4.9 & 4.14), and commit be2657752e9e
("mm: memcg: fix use after free in mem_cgroup_iter()") has been merged
to the trees. However, I can still observe use after free issues
addressed in the commit be2657752e9e. (on low-end devices, a few times
this month)
backtrace:
css_tryget <- crash here
mem_cgroup_iter
shrink_node
shrink_zones
do_try_to_free_pages
try_to_free_pages
__perform_reclaim
__alloc_pages_direct_reclaim
__alloc_pages_slowpath
__alloc_pages_nodemask
To debug, I poisoned mem_cgroup before freeing it:
static void __mem_cgroup_free(struct mem_cgroup *memcg)
for_each_node(node)
free_mem_cgroup_per_node_info(memcg, node);
free_percpu(memcg->stat);
+ /* poison memcg before freeing it */
+ memset(memcg, 0x78, sizeof(struct mem_cgroup));
kfree(memcg);
}
The coredump shows the position=0xdbbc2a00 is freed.
(gdb) p/x ((struct mem_cgroup_per_node *)0xe5009e00)->iter[8]
$13 = {position = 0xdbbc2a00, generation = 0x2efd}
0xdbbc2a00: 0xdbbc2e00 0x00000000 0xdbbc2800 0x00000100
0xdbbc2a10: 0x00000200 0x78787878 0x00026218 0x00000000
0xdbbc2a20: 0xdcad6000 0x00000001 0x78787800 0x00000000
0xdbbc2a30: 0x78780000 0x00000000 0x0068fb84 0x78787878
0xdbbc2a40: 0x78787878 0x78787878 0x78787878 0xe3fa5cc0
0xdbbc2a50: 0x78787878 0x78787878 0x00000000 0x00000000
0xdbbc2a60: 0x00000000 0x00000000 0x00000000 0x00000000
0xdbbc2a70: 0x00000000 0x00000000 0x00000000 0x00000000
0xdbbc2a80: 0x00000000 0x00000000 0x00000000 0x00000000
0xdbbc2a90: 0x00000001 0x00000000 0x00000000 0x00100000
0xdbbc2aa0: 0x00000001 0xdbbc2ac8 0x00000000 0x00000000
0xdbbc2ab0: 0x00000000 0x00000000 0x00000000 0x00000000
0xdbbc2ac0: 0x00000000 0x00000000 0xe5b02618 0x00001000
0xdbbc2ad0: 0x00000000 0x78787878 0x78787878 0x78787878
0xdbbc2ae0: 0x78787878 0x78787878 0x78787878 0x78787878
0xdbbc2af0: 0x78787878 0x78787878 0x78787878 0x78787878
0xdbbc2b00: 0x78787878 0x78787878 0x78787878 0x78787878
0xdbbc2b10: 0x78787878 0x78787878 0x78787878 0x78787878
0xdbbc2b20: 0x78787878 0x78787878 0x78787878 0x78787878
0xdbbc2b30: 0x78787878 0x78787878 0x78787878 0x78787878
0xdbbc2b40: 0x78787878 0x78787878 0x78787878 0x78787878
0xdbbc2b50: 0x78787878 0x78787878 0x78787878 0x78787878
0xdbbc2b60: 0x78787878 0x78787878 0x78787878 0x78787878
0xdbbc2b70: 0x78787878 0x78787878 0x78787878 0x78787878
0xdbbc2b80: 0x78787878 0x78787878 0x00000000 0x78787878
0xdbbc2b90: 0x78787878 0x78787878 0x78787878 0x78787878
0xdbbc2ba0: 0x78787878 0x78787878 0x78787878 0x78787878
In the reclaim path, try_to_free_pages() does not setup
sc.target_mem_cgroup and sc is passed to do_try_to_free_pages(), ...,
shrink_node().
In mem_cgroup_iter(), root is set to root_mem_cgroup because
sc->target_mem_cgroup is NULL. It is possible to assign a memcg to
root_mem_cgroup.nodeinfo.iter in mem_cgroup_iter().
try_to_free_pages
struct scan_control sc = {...}, target_mem_cgroup is 0x0;
do_try_to_free_pages
shrink_zones
shrink_node
mem_cgroup *root = sc->target_mem_cgroup;
memcg = mem_cgroup_iter(root, NULL, &reclaim);
mem_cgroup_iter()
if (!root)
root = root_mem_cgroup;
...
css = css_next_descendant_pre(css, &root->css);
memcg = mem_cgroup_from_css(css);
cmpxchg(&iter->position, pos, memcg);
My device uses memcg non-hierarchical mode. When we release a memcg:
invalidate_reclaim_iterators() reaches only dead_memcg and its parents.
If non-hierarchical mode is used, invalidate_reclaim_iterators() never
reaches root_mem_cgroup.
static void invalidate_reclaim_iterators(struct mem_cgroup *dead_memcg)
{
struct mem_cgroup *memcg = dead_memcg;
for (; memcg; memcg = parent_mem_cgroup(memcg)
...
}
So the use after free scenario looks like:
CPU1 CPU2
try_to_free_pages
do_try_to_free_pages
shrink_zones
shrink_node
mem_cgroup_iter()
if (!root)
root = root_mem_cgroup;
...
css = css_next_descendant_pre(css, &root->css);
memcg = mem_cgroup_from_css(css);
cmpxchg(&iter->position, pos, memcg);
invalidate_reclaim_iterators(memcg);
...
__mem_cgroup_free()
kfree(memcg);
try_to_free_pages
do_try_to_free_pages
shrink_zones
shrink_node
mem_cgroup_iter()
if (!root)
root = root_mem_cgroup;
...
mz = mem_cgroup_nodeinfo(root, reclaim->pgdat->node_id);
iter = &mz->iter[reclaim->priority];
pos = READ_ONCE(iter->position);
css_tryget(&pos->css) <- use after free
To avoid this, we should also invalidate root_mem_cgroup.nodeinfo.iter
in invalidate_reclaim_iterators().
[cai@lca.pw: fix -Wparentheses compilation warning]
Link: http://lkml.kernel.org/r/1564580753-17531-1-git-send-email-cai@lca.pw
Link: http://lkml.kernel.org/r/20190730015729.4406-1-miles.chen@mediatek.com
Fixes: 5ac8fb31ad2e ("mm: memcontrol: convert reclaim iterator to simple css refcounting")
Signed-off-by: Miles Chen <miles.chen@mediatek.com>
Signed-off-by: Qian Cai <cai@lca.pw>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit b997052bc3ac444a0bceab1093aff7ae71ed419e upstream.
The constraint from the zpool use of z3fold_destroy_pool() is there are
no outstanding handles to memory (so no active allocations), but it is
possible for there to be outstanding work on either of the two wqs in
the pool.
Calling z3fold_deregister_migration() before the workqueues are drained
means that there can be allocated pages referencing a freed inode,
causing any thread in compaction to be able to trip over the bad pointer
in PageMovable().
Link: http://lkml.kernel.org/r/20190726224810.79660-2-henryburns@google.com
Fixes: 1f862989b04a ("mm/z3fold.c: support page migration")
Signed-off-by: Henry Burns <henryburns@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Jonathan Adams <jwadams@google.com>
Cc: Vitaly Vul <vitaly.vul@sony.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Henry Burns <henrywolfeburns@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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 6051d3bd3b91e96c59e62b8be2dba1cc2b19ee40 upstream.
The constraint from the zpool use of z3fold_destroy_pool() is there are
no outstanding handles to memory (so no active allocations), but it is
possible for there to be outstanding work on either of the two wqs in
the pool.
If there is work queued on pool->compact_workqueue when it is called,
z3fold_destroy_pool() will do:
z3fold_destroy_pool()
destroy_workqueue(pool->release_wq)
destroy_workqueue(pool->compact_wq)
drain_workqueue(pool->compact_wq)
do_compact_page(zhdr)
kref_put(&zhdr->refcount)
__release_z3fold_page(zhdr, ...)
queue_work_on(pool->release_wq, &pool->work) *BOOM*
So compact_wq needs to be destroyed before release_wq.
Link: http://lkml.kernel.org/r/20190726224810.79660-1-henryburns@google.com
Fixes: 5d03a6613957 ("mm/z3fold.c: use kref to prevent page free/compact race")
Signed-off-by: Henry Burns <henryburns@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Jonathan Adams <jwadams@google.com>
Cc: Vitaly Vul <vitaly.vul@sony.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk
Cc: Henry Burns <henrywolfeburns@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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit a53190a4aaa36494f4d7209fd1fcc6f2ee08e0e0 upstream.
When running syzkaller internally, we ran into the below bug on 4.9.x
kernel:
kernel BUG at mm/huge_memory.c:2124!
invalid opcode: 0000 [#1] SMP KASAN
CPU: 0 PID: 1518 Comm: syz-executor107 Not tainted 4.9.168+ #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.5.1 01/01/2011
task: ffff880067b34900 task.stack: ffff880068998000
RIP: split_huge_page_to_list+0x8fb/0x1030 mm/huge_memory.c:2124
Call Trace:
split_huge_page include/linux/huge_mm.h:100 [inline]
queue_pages_pte_range+0x7e1/0x1480 mm/mempolicy.c:538
walk_pmd_range mm/pagewalk.c:50 [inline]
walk_pud_range mm/pagewalk.c:90 [inline]
walk_pgd_range mm/pagewalk.c:116 [inline]
__walk_page_range+0x44a/0xdb0 mm/pagewalk.c:208
walk_page_range+0x154/0x370 mm/pagewalk.c:285
queue_pages_range+0x115/0x150 mm/mempolicy.c:694
do_mbind mm/mempolicy.c:1241 [inline]
SYSC_mbind+0x3c3/0x1030 mm/mempolicy.c:1370
SyS_mbind+0x46/0x60 mm/mempolicy.c:1352
do_syscall_64+0x1d2/0x600 arch/x86/entry/common.c:282
entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: c7 80 1c 02 00 e8 26 0a 76 01 <0f> 0b 48 c7 c7 40 46 45 84 e8 4c
RIP [<ffffffff81895d6b>] split_huge_page_to_list+0x8fb/0x1030 mm/huge_memory.c:2124
RSP <ffff88006899f980>
with the below test:
uint64_t r[1] = {0xffffffffffffffff};
int main(void)
{
syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
intptr_t res = 0;
res = syscall(__NR_socket, 0x11, 3, 0x300);
if (res != -1)
r[0] = res;
*(uint32_t*)0x20000040 = 0x10000;
*(uint32_t*)0x20000044 = 1;
*(uint32_t*)0x20000048 = 0xc520;
*(uint32_t*)0x2000004c = 1;
syscall(__NR_setsockopt, r[0], 0x107, 0xd, 0x20000040, 0x10);
syscall(__NR_mmap, 0x20fed000, 0x10000, 0, 0x8811, r[0], 0);
*(uint64_t*)0x20000340 = 2;
syscall(__NR_mbind, 0x20ff9000, 0x4000, 0x4002, 0x20000340, 0x45d4, 3);
return 0;
}
Actually the test does:
mmap(0x20000000, 16777216, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x20000000
socket(AF_PACKET, SOCK_RAW, 768) = 3
setsockopt(3, SOL_PACKET, PACKET_TX_RING, {block_size=65536, block_nr=1, frame_size=50464, frame_nr=1}, 16) = 0
mmap(0x20fed000, 65536, PROT_NONE, MAP_SHARED|MAP_FIXED|MAP_POPULATE|MAP_DENYWRITE, 3, 0) = 0x20fed000
mbind(..., MPOL_MF_STRICT|MPOL_MF_MOVE) = 0
The setsockopt() would allocate compound pages (16 pages in this test)
for packet tx ring, then the mmap() would call packet_mmap() to map the
pages into the user address space specified by the mmap() call.
When calling mbind(), it would scan the vma to queue the pages for
migration to the new node. It would split any huge page since 4.9
doesn't support THP migration, however, the packet tx ring compound
pages are not THP and even not movable. So, the above bug is triggered.
However, the later kernel is not hit by this issue due to commit
d44d363f6578 ("mm: don't assume anonymous pages have SwapBacked flag"),
which just removes the PageSwapBacked check for a different reason.
But, there is a deeper issue. According to the semantic of mbind(), it
should return -EIO if MPOL_MF_MOVE or MPOL_MF_MOVE_ALL was specified and
MPOL_MF_STRICT was also specified, but the kernel was unable to move all
existing pages in the range. The tx ring of the packet socket is
definitely not movable, however, mbind() returns success for this case.
Although the most socket file associates with non-movable pages, but XDP
may have movable pages from gup. So, it sounds not fine to just check
the underlying file type of vma in vma_migratable().
Change migrate_page_add() to check if the page is movable or not, if it
is unmovable, just return -EIO. But do not abort pte walk immediately,
since there may be pages off LRU temporarily. We should migrate other
pages if MPOL_MF_MOVE* is specified. Set has_unmovable flag if some
paged could not be not moved, then return -EIO for mbind() eventually.
With this change the above test would return -EIO as expected.
[yang.shi@linux.alibaba.com: fix review comments from Vlastimil]
Link: http://lkml.kernel.org/r/1563556862-54056-3-git-send-email-yang.shi@linux.alibaba.com
Link: http://lkml.kernel.org/r/1561162809-59140-3-git-send-email-yang.shi@linux.alibaba.com
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
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MPOL_MF_STRICT were specified
commit d883544515aae54842c21730b880172e7894fde9 upstream.
When both MPOL_MF_MOVE* and MPOL_MF_STRICT was specified, mbind() should
try best to migrate misplaced pages, if some of the pages could not be
migrated, then return -EIO.
There are three different sub-cases:
1. vma is not migratable
2. vma is migratable, but there are unmovable pages
3. vma is migratable, pages are movable, but migrate_pages() fails
If #1 happens, kernel would just abort immediately, then return -EIO,
after a7f40cfe3b7a ("mm: mempolicy: make mbind() return -EIO when
MPOL_MF_STRICT is specified").
If #3 happens, kernel would set policy and migrate pages with
best-effort, but won't rollback the migrated pages and reset the policy
back.
Before that commit, they behaves in the same way. It'd better to keep
their behavior consistent. But, rolling back the migrated pages and
resetting the policy back sounds not feasible, so just make #1 behave as
same as #3.
Userspace will know that not everything was successfully migrated (via
-EIO), and can take whatever steps it deems necessary - attempt
rollback, determine which exact page(s) are violating the policy, etc.
Make queue_pages_range() return 1 to indicate there are unmovable pages
or vma is not migratable.
The #2 is not handled correctly in the current kernel, the following
patch will fix it.
[yang.shi@linux.alibaba.com: fix review comments from Vlastimil]
Link: http://lkml.kernel.org/r/1563556862-54056-2-git-send-email-yang.shi@linux.alibaba.com
Link: http://lkml.kernel.org/r/1561162809-59140-2-git-send-email-yang.shi@linux.alibaba.com
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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|
commit 1de13ee59225dfc98d483f8cce7d83f97c0b31de upstream.
When migrating an anonymous private page to a ZONE_DEVICE private page,
the source page->mapping and page->index fields are copied to the
destination ZONE_DEVICE struct page and the page_mapcount() is
increased. This is so rmap_walk() can be used to unmap and migrate the
page back to system memory.
However, try_to_unmap_one() computes the subpage pointer from a swap pte
which computes an invalid page pointer and a kernel panic results such
as:
BUG: unable to handle page fault for address: ffffea1fffffffc8
Currently, only single pages can be migrated to device private memory so
no subpage computation is needed and it can be set to "page".
[rcampbell@nvidia.com: add comment]
Link: http://lkml.kernel.org/r/20190724232700.23327-4-rcampbell@nvidia.com
Link: http://lkml.kernel.org/r/20190719192955.30462-4-rcampbell@nvidia.com
Fixes: a5430dda8a3a1c ("mm/migrate: support un-addressable ZONE_DEVICE page in migration")
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Vlastimil Babka <vbabka@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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 3f8fd02b1bf1d7ba964485a56f2f4b53ae88c167 upstream.
On x86-32 with PTI enabled, parts of the kernel page-tables are not shared
between processes. This can cause mappings in the vmalloc/ioremap area to
persist in some page-tables after the region is unmapped and released.
When the region is re-used the processes with the old mappings do not fault
in the new mappings but still access the old ones.
This causes undefined behavior, in reality often data corruption, kernel
oopses and panics and even spontaneous reboots.
Fix this problem by activly syncing unmaps in the vmalloc/ioremap area to
all page-tables in the system before the regions can be re-used.
References: https://bugzilla.suse.com/show_bug.cgi?id=1118689
Fixes: 5d72b4fba40ef ('x86, mm: support huge I/O mapping capability I/F')
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lkml.kernel.org/r/20190719184652.11391-4-joro@8bytes.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 7b358c6f12dc82364f6d317f8c8f1d794adbc3f5 upstream.
When CONFIG_MIGRATE_VMA_HELPER is enabled, migrate_vma() calls
migrate_vma_collect() which initializes a struct mm_walk but didn't
initialize mm_walk.pud_entry. (Found by code inspection) Use a C
structure initialization to make sure it is set to NULL.
Link: http://lkml.kernel.org/r/20190719233225.12243-1-rcampbell@nvidia.com
Fixes: 8763cb45ab967 ("mm/migrate: new memory migration helper for use with device memory")
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 670105a25608affe01cb0ccdc2a1f4bd2327172b upstream.
"howaboutsynergy" reported via kernel buzilla number 204165 that
compact_zone_order was consuming 100% CPU during a stress test for
prolonged periods of time. Specifically the following command, which
should exit in 10 seconds, was taking an excessive time to finish while
the CPU was pegged at 100%.
stress -m 220 --vm-bytes 1000000000 --timeout 10
Tracing indicated a pattern as follows
stress-3923 [007] 519.106208: mm_compaction_isolate_migratepages: range=(0x70bb80 ~ 0x70bb80) nr_scanned=0 nr_taken=0
stress-3923 [007] 519.106212: mm_compaction_isolate_migratepages: range=(0x70bb80 ~ 0x70bb80) nr_scanned=0 nr_taken=0
stress-3923 [007] 519.106216: mm_compaction_isolate_migratepages: range=(0x70bb80 ~ 0x70bb80) nr_scanned=0 nr_taken=0
stress-3923 [007] 519.106219: mm_compaction_isolate_migratepages: range=(0x70bb80 ~ 0x70bb80) nr_scanned=0 nr_taken=0
stress-3923 [007] 519.106223: mm_compaction_isolate_migratepages: range=(0x70bb80 ~ 0x70bb80) nr_scanned=0 nr_taken=0
stress-3923 [007] 519.106227: mm_compaction_isolate_migratepages: range=(0x70bb80 ~ 0x70bb80) nr_scanned=0 nr_taken=0
stress-3923 [007] 519.106231: mm_compaction_isolate_migratepages: range=(0x70bb80 ~ 0x70bb80) nr_scanned=0 nr_taken=0
stress-3923 [007] 519.106235: mm_compaction_isolate_migratepages: range=(0x70bb80 ~ 0x70bb80) nr_scanned=0 nr_taken=0
stress-3923 [007] 519.106238: mm_compaction_isolate_migratepages: range=(0x70bb80 ~ 0x70bb80) nr_scanned=0 nr_taken=0
stress-3923 [007] 519.106242: mm_compaction_isolate_migratepages: range=(0x70bb80 ~ 0x70bb80) nr_scanned=0 nr_taken=0
Note that compaction is entered in rapid succession while scanning and
isolating nothing. The problem is that when a task that is compacting
receives a fatal signal, it retries indefinitely instead of exiting
while making no progress as a fatal signal is pending.
It's not easy to trigger this condition although enabling zswap helps on
the basis that the timing is altered. A very small window has to be hit
for the problem to occur (signal delivered while compacting and
isolating a PFN for migration that is not aligned to SWAP_CLUSTER_MAX).
This was reproduced locally -- 16G single socket system, 8G swap, 30%
zswap configured, vm-bytes 22000000000 using Colin Kings stress-ng
implementation from github running in a loop until the problem hits).
Tracing recorded the problem occurring almost 200K times in a short
window. With this patch, the problem hit 4 times but the task existed
normally instead of consuming CPU.
This problem has existed for some time but it was made worse by commit
cf66f0700c8f ("mm, compaction: do not consider a need to reschedule as
contention"). Before that commit, if the same condition was hit then
locks would be quickly contended and compaction would exit that way.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=204165
Link: http://lkml.kernel.org/r/20190718085708.GE24383@techsingularity.net
Fixes: cf66f0700c8f ("mm, compaction: do not consider a need to reschedule as contention")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org> [5.1+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit ebdf4de5642fb6580b0763158b6b4b791c4d6a4d upstream.
buffer_migrate_page_norefs() can race with bh users in the following
way:
CPU1 CPU2
buffer_migrate_page_norefs()
buffer_migrate_lock_buffers()
checks bh refs
spin_unlock(&mapping->private_lock)
__find_get_block()
spin_lock(&mapping->private_lock)
grab bh ref
spin_unlock(&mapping->private_lock)
move page do bh work
This can result in various issues like lost updates to buffers (i.e.
metadata corruption) or use after free issues for the old page.
This patch closes the race by holding mapping->private_lock while the
mapping is being moved to a new page. Ordinarily, a reference can be
taken outside of the private_lock using the per-cpu BH LRU but the
references are checked and the LRU invalidated if necessary. The
private_lock is held once the references are known so the buffer lookup
slow path will spin on the private_lock. Between the page lock and
private_lock, it should be impossible for other references to be
acquired and updates to happen during the migration.
A user had reported data corruption issues on a distribution kernel with
a similar page migration implementation as mainline. The data
corruption could not be reproduced with this patch applied. A small
number of migration-intensive tests were run and no performance problems
were noted.
[mgorman@techsingularity.net: Changelog, removed tracing]
Link: http://lkml.kernel.org/r/20190718090238.GF24383@techsingularity.net
Fixes: 89cb0888ca14 "mm: migrate: provide buffer_migrate_page_norefs()"
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org> [5.0+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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shrinker
commit fa1e512fac717f34e7c12d7a384c46e90a647392 upstream.
Shakeel Butt reported premature oom on kernel with
"cgroup_disable=memory" since mem_cgroup_is_root() returns false even
though memcg is actually NULL. The drop_caches is also broken.
It is because commit aeed1d325d42 ("mm/vmscan.c: generalize
shrink_slab() calls in shrink_node()") removed the !memcg check before
!mem_cgroup_is_root(). And, surprisingly root memcg is allocated even
though memory cgroup is disabled by kernel boot parameter.
Add mem_cgroup_disabled() check to make reclaimer work as expected.
Link: http://lkml.kernel.org/r/1563385526-20805-1-git-send-email-yang.shi@linux.alibaba.com
Fixes: aeed1d325d42 ("mm/vmscan.c: generalize shrink_slab() calls in shrink_node()")
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Reported-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Jan Hadrava <had@kam.mff.cuni.cz>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: <stable@vger.kernel.org> [4.19+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit eca499ab3749a4537dee77ffead47a1a2c0dee19 ]
Presently the remove_memory() interface is inherently broken. It tries
to remove memory but panics if some memory is not offline. The problem
is that it is impossible to ensure that all memory blocks are offline as
this function also takes lock_device_hotplug that is required to change
memory state via sysfs.
So, between calling this function and offlining all memory blocks there
is always a window when lock_device_hotplug is released, and therefore,
there is always a chance for a panic during this window.
Make this interface to return an error if memory removal fails. This
way it is safe to call this function without panicking machine, and also
makes it symmetric to add_memory() which already returns an error.
Link: http://lkml.kernel.org/r/20190517215438.6487-3-pasha.tatashin@soleen.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Ross Zwisler <zwisler@kernel.org>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit c633324e311243586675e732249339685e5d6faa ]
The description of cma_declare_contiguous() indicates that if the
'fixed' argument is true the reserved contiguous area must be exactly at
the address of the 'base' argument.
However, the function currently allows the 'base', 'size', and 'limit'
arguments to be silently adjusted to meet alignment constraints. This
commit enforces the documented behavior through explicit checks that
return an error if the region does not fit within a specified region.
Link: http://lkml.kernel.org/r/1561422051-16142-1-git-send-email-opendmb@gmail.com
Fixes: 5ea3b1b2f8ad ("cma: add placement specifier for "cma=" kernel parameter")
Signed-off-by: Doug Berger <opendmb@gmail.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Cc: Yue Hu <huyue2@yulong.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
Jane Chu
David Hildenbrand
Mike Rapoport
Honglei Wang
Vlastimil Babka
Qian Cai
Dan Carpenter
Vitaly Wool
Kees Cook
Jan Kara
Michal Hocko
Tetsuo Handa
Yafang Shao
Gustavo A. R. Silva
Henry Burns
Shakeel Butt
Roman Gushchin
Andrew Morton
Andrey Ryabinin
David Rientjes
Yang Shi
Christoph Hellwig
Mel Gorman
Isaac J. Manjarres
Miles Chen
Ralph Campbell
Joerg Roedel
Pavel Tatashin
Doug Berger