linux-toradex.git/mm, branch v6.8-rc4

Merge tag 'mm-hotfixes-stable-2024-02-10-11-16' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2024-02-10T23:28:07+00:00

Pull misc fixes from Andrew Morton:
 "21 hotfixes. 12 are cc:stable and the remainder pertain to post-6.7
  issues or aren't considered to be needed in earlier kernel versions"

* tag 'mm-hotfixes-stable-2024-02-10-11-16' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (21 commits)
  nilfs2: fix potential bug in end_buffer_async_write
  mm/damon/sysfs-schemes: fix wrong DAMOS tried regions update timeout setup
  nilfs2: fix hang in nilfs_lookup_dirty_data_buffers()
  MAINTAINERS: Leo Yan has moved
  mm/zswap: don't return LRU_SKIP if we have dropped lru lock
  fs,hugetlb: fix NULL pointer dereference in hugetlbs_fill_super
  mailmap: switch email address for John Moon
  mm: zswap: fix objcg use-after-free in entry destruction
  mm/madvise: don't forget to leave lazy MMU mode in madvise_cold_or_pageout_pte_range()
  arch/arm/mm: fix major fault accounting when retrying under per-VMA lock
  selftests: core: include linux/close_range.h for CLOSE_RANGE_* macros
  mm/memory-failure: fix crash in split_huge_page_to_list from soft_offline_page
  mm: memcg: optimize parent iteration in memcg_rstat_updated()
  nilfs2: fix data corruption in dsync block recovery for small block sizes
  mm/userfaultfd: UFFDIO_MOVE implementation should use ptep_get()
  exit: wait_task_zombie: kill the no longer necessary spin_lock_irq(siglock)
  fs/proc: do_task_stat: use sig->stats_lock to gather the threads/children stats
  fs/proc: do_task_stat: move thread_group_cputime_adjusted() outside of lock_task_sighand()
  getrusage: use sig->stats_lock rather than lock_task_sighand()
  getrusage: move thread_group_cputime_adjusted() outside of lock_task_sighand()
  ...

Merge tag 'block-6.8-2024-02-10' of git://git.kernel.dk/linux

2024-02-10T16:02:48+00:00

Pull block fixes from Jens Axboe:

 - NVMe pull request via Keith:
     - Update a potentially stale firmware attribute (Maurizio)
     - Fixes for the recent verbose error logging (Keith, Chaitanya)
     - Protection information payload size fix for passthrough (Francis)

 - Fix for a queue freezing issue in virtblk (Yi)

 - blk-iocost underflow fix (Tejun)

 - blk-wbt task detection fix (Jan)

* tag 'block-6.8-2024-02-10' of git://git.kernel.dk/linux:
  virtio-blk: Ensure no requests in virtqueues before deleting vqs.
  blk-iocost: Fix an UBSAN shift-out-of-bounds warning
  nvme: use ns->head->pi_size instead of t10_pi_tuple structure size
  nvme-core: fix comment to reflect right functions
  nvme: move passthrough logging attribute to head
  blk-wbt: Fix detection of dirty-throttled tasks
  nvme-host: fix the updating of the firmware version

mm/damon/sysfs-schemes: fix wrong DAMOS tried regions update timeout setup

2024-02-08T05:20:36+00:00

DAMON sysfs interface's update_schemes_tried_regions command has a timeout
of two apply intervals of the DAMOS scheme.  Having zero value DAMOS
scheme apply interval means it will use the aggregation interval as the
value.  However, the timeout setup logic is mistakenly using the sampling
interval insted of the aggregartion interval for the case.  This could
cause earlier-than-expected timeout of the command.  Fix it.

Link: https://lkml.kernel.org/r/20240202191956.88791-1-sj@kernel.org
Fixes: 7d6fa31a2fd7 ("mm/damon/sysfs-schemes: add timeout for update_schemes_tried_regions")
Signed-off-by: SeongJae Park 
Cc:  # 6.7.x
Signed-off-by: Andrew Morton

mm/zswap: don't return LRU_SKIP if we have dropped lru lock

2024-02-08T05:20:36+00:00

LRU_SKIP can only be returned if we don't ever dropped lru lock, or we
need to return LRU_RETRY to restart from the head of lru list.

Otherwise, the iteration might continue from a cursor position that was
freed while the locks were dropped.

Actually we may need to introduce another LRU_STOP to really terminate the
ongoing shrinking scan process, when we encounter a warm page already in
the swap cache.  The current list_lru implementation doesn't have this
function to early break from __list_lru_walk_one.

Link: https://lkml.kernel.org/r/20240126-zswap-writeback-race-v2-1-b10479847099@bytedance.com
Fixes: b5ba474f3f51 ("zswap: shrink zswap pool based on memory pressure")
Signed-off-by: Chengming Zhou 
Acked-by: Johannes Weiner 
Reviewed-by: Nhat Pham 
Cc: Chris Li 
Cc: Yosry Ahmed 
Signed-off-by: Andrew Morton

mm: zswap: fix objcg use-after-free in entry destruction

2024-02-08T05:20:35+00:00

In the per-memcg LRU universe, LRU removal uses entry->objcg to determine
which list count needs to be decreased.  Drop the objcg reference after
updating the LRU, to fix a possible use-after-free.

Link: https://lkml.kernel.org/r/20240130013438.565167-1-hannes@cmpxchg.org
Fixes: a65b0e7607cc ("zswap: make shrinking memcg-aware")
Signed-off-by: Johannes Weiner 
Acked-by: Yosry Ahmed 
Reviewed-by: Nhat Pham 
Reviewed-by: Chengming Zhou 
Signed-off-by: Andrew Morton

mm/madvise: don't forget to leave lazy MMU mode in madvise_cold_or_pageout_pte_range()

2024-02-08T05:20:35+00:00

We need to leave lazy MMU mode before unlocking.

Link: https://lkml.kernel.org/r/20240126032608.355899-1-senozhatsky@chromium.org
Fixes: b2f557a21bc8 ("mm/madvise: add cond_resched() in madvise_cold_or_pageout_pte_range()")
Signed-off-by: Sergey Senozhatsky 
Cc: Jiexun Wang 
Signed-off-by: Andrew Morton

mm/memory-failure: fix crash in split_huge_page_to_list from soft_offline_page

2024-02-08T05:20:34+00:00

When I did soft offline stress test, a machine was observed to crash with
the following message:

  kernel BUG at include/linux/memcontrol.h:554!
  invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
  CPU: 5 PID: 3837 Comm: hwpoison.sh Not tainted 6.7.0-next-20240112-00001-g8ecf3e7fb7c8-dirty #97
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
  RIP: 0010:folio_memcg+0xaf/0xd0
  Code: 10 5b 5d c3 cc cc cc cc 48 c7 c6 08 b1 f2 b2 48 89 ef e8 b4 c5 f8 ff 90 0f 0b 48 c7 c6 d0 b0 f2 b2 48 89 ef e8 a2 c5 f8 ff 90 <0f> 0b 48 c7 c6 08 b1 f2 b2 48 89 ef e8 90 c5 f8 ff 90 0f 0b 66 66
  RSP: 0018:ffffb6c043657c98 EFLAGS: 00000296
  RAX: 000000000000004b RBX: ffff932bc1d1e401 RCX: ffff933abfb5c908
  RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff933abfb5c900
  RBP: ffffea6f04019080 R08: ffffffffb3338ce8 R09: 0000000000009ffb
  R10: 00000000000004dd R11: ffffffffb3308d00 R12: ffffea6f04019080
  R13: ffffea6f04019080 R14: 0000000000000001 R15: ffffb6c043657da0
  FS:  00007f6c60f6b740(0000) GS:ffff933abfb40000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000559c3bc8b980 CR3: 0000000107f1c000 CR4: 00000000000006f0
  Call Trace:
   
   split_huge_page_to_list+0x4d/0x1380
   try_to_split_thp_page+0x3a/0xf0
   soft_offline_page+0x1ea/0x8a0
   soft_offline_page_store+0x52/0x90
   kernfs_fop_write_iter+0x118/0x1b0
   vfs_write+0x30b/0x430
   ksys_write+0x5e/0xe0
   do_syscall_64+0xb0/0x1b0
   entry_SYSCALL_64_after_hwframe+0x6d/0x75
  RIP: 0033:0x7f6c60d14697
  Code: 10 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
  RSP: 002b:00007ffe9b72b8d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
  RAX: ffffffffffffffda RBX: 000000000000000c RCX: 00007f6c60d14697
  RDX: 000000000000000c RSI: 0000559c3bc8b980 RDI: 0000000000000001
  RBP: 0000559c3bc8b980 R08: 00007f6c60dd1460 R09: 000000007fffffff
  R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000000c
  R13: 00007f6c60e1a780 R14: 00007f6c60e16600 R15: 00007f6c60e15a00

The problem is that page->mapping is overloaded with slab->slab_list or
slabs fields now, so slab pages could be taken as non-LRU movable pages if
field slabs contains PAGE_MAPPING_MOVABLE or slab_list->prev is set to
LIST_POISON2.  These slab pages will be treated as thp later leading to
crash in split_huge_page_to_list().

Link: https://lkml.kernel.org/r/20240126065837.2100184-1-linmiaohe@huawei.com
Link: https://lkml.kernel.org/r/20240124084014.1772906-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin 
Fixes: 130d4df57390 ("mm/sl[au]b: rearrange struct slab fields to allow larger rcu_head")
Reviewed-by: Matthew Wilcox (Oracle) 
Cc: Miaohe Lin 
Cc: Naoya Horiguchi 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton

mm: memcg: optimize parent iteration in memcg_rstat_updated()

2024-02-08T05:20:34+00:00

In memcg_rstat_updated(), we iterate the memcg being updated and its
parents to update memcg->vmstats_percpu->stats_updates in the fast path
(i.e. no atomic updates). According to my math, this is 3 memory loads
(and potentially 3 cache misses) per memcg:
- Load the address of memcg->vmstats_percpu.
- Load vmstats_percpu->stats_updates (based on some percpu calculation).
- Load the address of the parent memcg.

Avoid most of the cache misses by caching a pointer from each struct
memcg_vmstats_percpu to its parent on the corresponding CPU. In this
case, for the first memcg we have 2 memory loads (same as above):
- Load the address of memcg->vmstats_percpu.
- Load vmstats_percpu->stats_updates (based on some percpu calculation).

Then for each additional memcg, we need a single load to get the
parent's stats_updates directly. This reduces the number of loads from
O(3N) to O(2+N) -- where N is the number of memcgs we need to iterate.

Additionally, stash a pointer to memcg->vmstats in each struct
memcg_vmstats_percpu such that we can access the atomic counter that all
CPUs fold into, memcg->vmstats->stats_updates.
memcg_should_flush_stats() is changed to memcg_vmstats_needs_flush() to
accept a struct memcg_vmstats pointer accordingly.

In struct memcg_vmstats_percpu, make sure both pointers together with
stats_updates live on the same cacheline. Finally, update
mem_cgroup_alloc() to take in a parent pointer and initialize the new
cache pointers on each CPU. The percpu loop in mem_cgroup_alloc() may
look concerning, but there are multiple similar loops in the cgroup
creation path (e.g. cgroup_rstat_init()), most of which are hidden
within alloc_percpu().

According to Oliver's testing [1], this fixes multiple 30-38%
regressions in vm-scalability, will-it-scale-tlb_flush2, and
will-it-scale-fallocate1. This comes at a cost of 2 more pointers per
CPU (<2KB on a machine with 128 CPUs).

[1] https://lore.kernel.org/lkml/ZbDJsfsZt2ITyo61@xsang-OptiPlex-9020/

[yosryahmed@google.com: fix struct memcg_vmstats_percpu size and alignment]
  Link: https://lkml.kernel.org/r/20240203044612.1234216-1-yosryahmed@google.com
Link: https://lkml.kernel.org/r/20240124100023.660032-1-yosryahmed@google.com
Signed-off-by: Yosry Ahmed 
Fixes: 8d59d2214c23 ("mm: memcg: make stats flushing threshold per-memcg")
Tested-by: kernel test robot 
Reported-by: kernel test robot 
Closes: https://lore.kernel.org/oe-lkp/202401221624.cb53a8ca-oliver.sang@intel.com
Acked-by: Shakeel Butt 
Acked-by: Johannes Weiner 
Cc: Michal Hocko 
Cc: Muchun Song 
Cc: Roman Gushchin 
Cc: Greg Thelen 
Signed-off-by: Andrew Morton

mm/userfaultfd: UFFDIO_MOVE implementation should use ptep_get()

2024-02-08T05:20:33+00:00

Commit c33c794828f2 ("mm: ptep_get() conversion") converted all (non-arch)
call sites to use ptep_get() instead of doing a direct dereference of the
pte.  Full rationale can be found in that commit's log.

Since then, UFFDIO_MOVE has been implemented which does 7 direct pte
dereferences.  Let's fix those up to use ptep_get().

I've asserted in the past that there is no reliable automated mechanism to
catch these; I'm relying on a combination of Coccinelle (which throws up a
lot of false positives) and some compiler magic to force a compiler error
on dereference.  But given the frequency with which new issues are coming
up, I'll add it to my todo list to try to find an automated solution.

Link: https://lkml.kernel.org/r/20240123141755.3836179-1-ryan.roberts@arm.com
Fixes: adef440691ba ("userfaultfd: UFFDIO_MOVE uABI")
Signed-off-by: Ryan Roberts 
Reviewed-by: Suren Baghdasaryan 
Cc: Andrea Arcangeli 
Cc: David Hildenbrand 
Signed-off-by: Andrew Morton

blk-wbt: Fix detection of dirty-throttled tasks

2024-02-06T16:44:03+00:00

The detection of dirty-throttled tasks in blk-wbt has been subtly broken
since its beginning in 2016. Namely if we are doing cgroup writeback and
the throttled task is not in the root cgroup, balance_dirty_pages() will
set dirty_sleep for the non-root bdi_writeback structure. However
blk-wbt checks dirty_sleep only in the root cgroup bdi_writeback
structure. Thus detection of recently throttled tasks is not working in
this case (we noticed this when we switched to cgroup v2 and suddently
writeback was slow).

Since blk-wbt has no easy way to get to proper bdi_writeback and
furthermore its intention has always been to work on the whole device
rather than on individual cgroups, just move the dirty_sleep timestamp
from bdi_writeback to backing_dev_info. That fixes the checking for
recently throttled task and saves memory for everybody as a bonus.

CC: stable@vger.kernel.org
Fixes: b57d74aff9ab ("writeback: track if we're sleeping on progress in balance_dirty_pages()")
Signed-off-by: Jan Kara 
Link: https://lore.kernel.org/r/20240123175826.21452-1-jack@suse.cz
[axboe: fixup indentation errors]
Signed-off-by: Jens Axboe