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The partial-page check compares against HPAGE_SIZE (PMD_SIZE), which is
wrong for gigantic hugetlb hstates (e.g. 1G). The walker hands the
callback a huge_page_size()-sized range, never start + HPAGE_SIZE, so the
comparison always declares it partial and aborts the WP. Compare against
the actual hstate's page size.
Link: https://lore.kernel.org/20260529172331.356655-3-kas@kernel.org
Fixes: 52526ca7fdb9 ("fs/proc/task_mmu: implement IOCTL to get and optionally clear info about PTEs")
Signed-off-by: Kiryl Shutsemau <kas@kernel.org>
Reported-by: Sashiko AI review <sashiko-bot@kernel.org>
Reviewed-by: Lorenzo Stoakes <ljs@kernel.org>
Reviewed-by: Dev Jain <dev.jain@arm.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Balbir Singh <balbirs@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "userfaultfd/pagemap: pre-existing fixes".
These are pre-existing bug fixes that were carried at the front of the
userfaultfd RWP working-set-tracking series up to v5 [1]. Per review
feedback that fixes should not sit in the middle of a feature series, they
are split out and sent on their own; the RWP series is reposted rebased on
top of this.
All six were flagged by the Sashiko AI review of the RWP series and carry
Reported-by: Sashiko AI review <sashiko-bot@kernel.org>. They are
independent of RWP, apply to mm-new directly, and carry Cc: stable@.
1: fs/proc/task_mmu: a missing huge_ptep_modify_prot_start() in
make_uffd_wp_huge_pte() can lose hardware Dirty/Accessed updates
when PAGEMAP_SCAN write-protects a hugetlb PTE.
2: fs/proc/task_mmu: pagemap_scan_hugetlb_entry() compares the range
against HPAGE_SIZE rather than the hstate page size, so it never
write-protects gigantic hugetlb pages.
3: fs/proc/task_mmu: PAGEMAP_SCAN with PM_SCAN_WP_MATCHING over an
unpopulated hugetlb range self-deadlocks -- pagemap_scan_pte_hole()
calls uffd_wp_range() while walk_hugetlb_range() holds the hugetlb
vma lock for read, and hugetlb_change_protection() then takes it
for write. Install the marker inline instead.
4: mm/huge_memory: change_non_present_huge_pmd() drops pmd_swp_uffd_wp
on a device-private PMD permission downgrade, silently losing the
uffd-wp marker.
5: userfaultfd: must_wait() applies pte_write() to a locklessly read
PTE without checking pte_present(), so swap/migration entries
decode random offset bits and a thread can stay parked on a stale
fault.
6: userfaultfd: __VMA_UFFD_FLAGS feeds VMA_UFFD_MINOR_BIT (41) to
mk_vma_flags() unconditionally, an out-of-bounds write into the
single-word vma_flags_t on 32-bit. Build the mask from config-gated
per-mode masks so an unavailable bit is never materialised.
This patch (of 6):
make_uffd_wp_huge_pte() arms the UFFD_WP bit on a present HugeTLB PTE by
calling huge_ptep_modify_prot_commit() with a ptent snapshot that was
fetched without the corresponding huge_ptep_modify_prot_start(). The
start helper is what atomically clears the entry so the kernel-owned
snapshot stays consistent until the commit; without it, the hardware may
set Dirty or Accessed in the live PTE between the original read and the
commit, and huge_ptep_modify_prot_commit() (whose generic implementation
just calls set_huge_pte_at()) then writes the stale snapshot back over the
live hardware bits, losing the update.
The non-hugetlb sibling make_uffd_wp_pte() does this correctly via
ptep_modify_prot_start() / ptep_modify_prot_commit(). Mirror that pattern
for the present-PTE branch. The migration case stays as-is -- migration
entries are non-present, so there's no hardware update to race against.
Link: https://lore.kernel.org/20260529172331.356655-1-kas@kernel.org
Link: https://lore.kernel.org/20260529172331.356655-2-kas@kernel.org
Link: https://lore.kernel.org/all/20260526130509.2748441-1-kirill@shutemov.name/ [1]
Fixes: 52526ca7fdb9 ("fs/proc/task_mmu: implement IOCTL to get and optionally clear info about PTEs")
Signed-off-by: Kiryl Shutsemau <kas@kernel.org>
Reported-by: Sashiko AI review <sashiko-bot@kernel.org>
Reviewed-by: Lorenzo Stoakes <ljs@kernel.org>
Reviewed-by: Dev Jain <dev.jain@arm.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Balbir Singh <balbirs@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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A few mm subsystem entries in MAINTAINERS are missing their testing ABI
documents. Add those.
Link: https://lore.kernel.org/20260601235506.85123-1-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Lorenzo Stoakes <ljs@kernel.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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These comments have been wrong since commit a211c6550efc ("mm: page_alloc:
defrag_mode kswapd/kcompactd watermarks") added NR_FREE_PAGES_BLOCKS.
Since nobody has complained about it in the last year, it seems unlikely
these comments were particularly useful anyway, so delete them.
Link: https://lore.kernel.org/20260601-zone_stat_item-comment-v1-1-f452dd91d5eb@google.com
Signed-off-by: Brendan Jackman <jackmanb@google.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Lorenzo Stoakes <ljs@kernel.org>
Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Move the kvcalloc() calls after the early return checks to avoid leaking
src_pfns and dst_pfns when end < start or mmget_not_zero() fails.
Link: https://lore.kernel.org/20260528011336.20797-1-hao.ge@linux.dev
Fixes: 775465fd26a3 ("lib/test_hmm: add zone device private THP test infrastructure")
Signed-off-by: Hao Ge <hao.ge@linux.dev>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Reported-by: Sashiko <sashiko-bot@kernel.org>
Reviewed-by: Balbir Singh <balbirs@nvidia.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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After "zram: fix use-after-free in zram_bvec_write_partial()",
zram_bvec_write_partial() always passes NULL to zram_read_page() and no
longer needs the parent bio. Mirror the read side
(zram_bvec_read_partial() has not taken a bio since commit 4e3c87b9421d
("zram: fix synchronous reads")) and drop the parameter from
zram_bvec_write_partial() and zram_bvec_write().
No functional change.
Link: https://lore.kernel.org/20260528-zram-v3-2-cab86eef8764@gmail.com
Signed-off-by: Cunlong Li <shenxiaogll@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Yisheng Xie <xieyisheng1@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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When not holding the lock, there is a chance that the pte gets modified
under our feet, so we need to use the lockless API to make sure that the
entries remain consistent during the read."
Switch from ptep_get() to ptep_get_lockless() accessor for PTE reads when
no lock is taken.
[osalvador@suse.de: changelog addition]
Link: https://lore.kernel.org/ahhNq0pFKvSKZQbR@localhost.localdomain
Link: https://lore.kernel.org/20260528075507.1821939-1-agordeev@linux.ibm.com
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Oscar Salvador (SUSE) <osalvador@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Lorenzo Stoakes <ljs@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Harry Yoo <harry@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Liam Howlett <liam@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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COMPACT_DEFERRED means compaction did not start because past failures
caused the zone to be deferred. try_to_compact_pages() returns the
maximum result seen while walking the zonelist, so a final
COMPACT_DEFERRED result means no later zone reported that compaction
actually ran.
__alloc_pages_direct_compact() skips COMPACTSTALL and COMPACTFAIL
accounting when try_to_compact_pages() returns COMPACT_SKIPPED, but not
when it returns COMPACT_DEFERRED. A deferred-only direct compaction
attempt can therefore look like a stall, and then a failure if the
allocation still cannot be satisfied.
Treat COMPACT_DEFERRED like COMPACT_SKIPPED in this accounting path. If a
later zone runs compaction and returns a result above COMPACT_DEFERRED, or
compact_zone_order() reports COMPACT_SUCCESS for a captured page, the
final result is not COMPACT_DEFERRED and the existing accounting still
runs.
Link: https://lore.kernel.org/tencent_368AF1F3821E46232637BE16D65C45CF3308@qq.com
Fixes: 06dac2f467fe ("mm: compaction: update the COMPACT[STALL|FAIL] events properly")
Signed-off-by: fujunjie <fujunjie1@qq.com>
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The force_thp_readahead path in do_sync_mmap_readahead() is gated on
HPAGE_PMD_ORDER <= MAX_PAGECACHE_ORDER and always requests HPAGE_PMD_ORDER
/ HPAGE_PMD_NR. On configurations where HPAGE_PMD_ORDER exceeds
MAX_PAGECACHE_ORDER, notably arm64 with a 64K base page size, VM_HUGEPAGE
mappings cannot use this path and fall back to the non-forced mmap
readahead path even when the mapping supports useful large folios.
Enable forced readahead for mappings that support large folios and request
the max folio order supported by the mapping, capped at 2M. 2MB is chosen
as the cap because it matches the PMD size on x86_64 and on arm64 with 4K
base pages, so the size/memory-pressure tradeoff for folios of that size
is already well understood. On arm64 with 16K and 64K base page sizes,
2MB is also the contiguous-PTE (contpte) block size, so the resulting
folios coalesce into a single TLB entry and reduce TLB pressure on the
readahead path. This will result in 32M folios not being faulted in with
16K base page size for arm64, but with contpte, the performance difference
should be negligible.
The final allocation order may still be clamped by page_cache_ra_order()
to the mapping and request geometry, but this gives VM_HUGEPAGE mappings
on such configurations a large-folio readahead request instead of dropping
back to base-page readahead.
Link: https://lore.kernel.org/20260601102205.3985788-3-usama.arif@linux.dev
Signed-off-by: Usama Arif <usama.arif@linux.dev>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Heiher <r@hev.cc>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kees Cook <kees@kernel.org>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Rohan McLure <rmclure@linux.ibm.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Kiryl Shutsemau (Meta) <kas@kernel.org>
Cc: Oscar Salvador (SUSE) <osalvador@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "mm: improve large folio readahead for exec memory", v7.
Two checks in do_sync_mmap_readahead() limit large-folio readahead:
1. The mmap_miss heuristic is meant to throttle wasteful speculative
readahead. It is currently also applied to the VM_EXEC readahead
path, which is targeted rather than speculative. Once mmap_miss exceeds
MMAP_LOTSAMISS, exec readahead - including the large-folio
order requested by exec_folio_order() - is disabled. On
configurations where the mmap_miss decrement paths are not
active (see patch 1) the counter only grows, so exec readahead
is permanently disabled after the first 100 faults.
2. The force_thp_readahead path is gated only on
HPAGE_PMD_ORDER <= MAX_PAGECACHE_ORDER and always drives the
readahead at HPAGE_PMD_ORDER. Configurations where
HPAGE_PMD_ORDER exceeds MAX_PAGECACHE_ORDER never reach this
path, even when the mapping itself supports usefully large
folios well below the cap.
Both issues are most visible on arm64 with a 64K base page size, where
HPAGE_PMD_ORDER is 13 (512MB) -- above MAX_PAGECACHE_ORDER (11) -- and
where fault_around_pages collapses to 1 disabling should_fault_around()
(one of the two mmap_miss decrement sites). However the fixes are
architecture-agnostic: patch 1 reflects the nature of VM_EXEC readahead
regardless of base page size, and patch 2 generalises the gate so any
mapping advertising a usefully large maximum folio order can benefit.
I created a benchmark that mmaps a large executable file madvises it as
huge and calls RET-stub functions at PAGE_SIZE offsets across it. "Cold"
measures fault + readahead cost. "Random" first faults in all pages with
a sequential sweep (not measured), then measures time for calling random
offsets, isolating iTLB miss cost for scattered execution.
The benchmark results on Neoverse V2 (Grace), arm64 with 64K base pages,
512MB executable file on ext4, averaged over 3 runs:
Phase | Baseline | Patched | Improvement
-----------|--------------|--------------|------------------
Cold fault | 83.4 ms | 41.3 ms | 50% faster
Random | 76.0 ms | 58.3 ms | 23% faster
This patch (of 2):
The mmap_miss heuristic is intended to stop speculative mmap readahead
when a file looks like a random-access workload. That does not fit the
VM_EXEC path very well.
VM_EXEC readahead is already constrained differently from ordinary mmap
read-around: it is bounded by the VMA, uses exec_folio_order() to choose
an order useful for executable mappings, and sets async_size to 0 so it
does not create follow-on readahead. When VM_HUGEPAGE is also present,
the larger readahead is an explicit userspace opt-in.
The mmap_miss counter is decremented from cache-hit paths in
do_async_mmap_readahead() and filemap_map_pages(). Those paths are not
always enough to balance the synchronous miss increments for executable
mappings. In particular, when fault-around is effectively disabled, such
as configurations where fault_around_pages is 1, filemap_map_pages() is
not reached from the fault path. The counter can then become a stale
throttle for VM_EXEC mappings and suppress the readahead behavior that the
executable-specific path is trying to provide.
Skip both mmap_miss increments and decrements for VM_EXEC mappings,
matching the existing VM_SEQ_READ treatment and keeping the counter
accounting symmetric.
Link: https://lore.kernel.org/20260601102205.3985788-1-usama.arif@linux.dev
Link: https://lore.kernel.org/20260601102205.3985788-2-usama.arif@linux.dev
Signed-off-by: Usama Arif <usama.arif@linux.dev>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Kiryl Shutsemau (Meta) <kas@kernel.org>
Reviewed-by: Oscar Salvador (SUSE) <osalvador@kernel.org>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Heiher <r@hev.cc>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kees Cook <kees@kernel.org>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Rohan McLure <rmclure@linux.ibm.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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should_compact_retry() handles COMPACT_SKIPPED by asking
compaction_zonelist_suitable() whether reclaim can make a later compaction
attempt worthwhile. That answer is used for the current allocation, so it
should follow the same zone eligibility rules as the allocation itself.
When cpusets are enabled, allocator slowpath decisions are marked with
ALLOC_CPUSET. The allocation path, direct compaction and reclaim retry
all skip zones rejected by __cpuset_zone_allowed().
compaction_zonelist_suitable() does not apply that filter. It only walks
ac->zonelist/ac->nodemask, so it can return true because a zone that is
not usable for the current allocation would pass __compaction_suitable().
That does not let the allocation use the disallowed zone. Later
allocation and direct compaction paths still apply cpuset filtering.
However, it can make should_compact_retry() retry based on memory that
this allocation cannot use.
Pass gfp_mask down and apply the same ALLOC_CPUSET check in
compaction_zonelist_suitable(). This keeps the retry decision aligned
with the zones that the allocation is allowed to use.
A temporary debugfs probe was also used to call the old and new
compaction_zonelist_suitable() predicates in the same two-node NUMA guest.
The task was restricted to mems=0 while ac->nodemask covered nodes 0-1.
After putting pressure on node0, node0 failed __compaction_suitable() for
order-10 and node1 passed it, but node1 was rejected by
__cpuset_zone_allowed(). In that state the old predicate returned true
and the patched predicate returned false.
Link: https://lore.kernel.org/tencent_F59F2BA2CC5779308E10DF54593C736D3E0A@qq.com
Fixes: 435b3894e742 ("mm:page_alloc: fix the NULL ac->nodemask in __alloc_pages_slowpath()")
Signed-off-by: fujunjie <fujunjie1@qq.com>
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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deferred_split_count() returns the raw list_lru count. When the
per-memcg, per-node list is empty, that count is 0.
That skips scanning, but it does not tell memcg reclaim that the shrinker
is empty. shrink_slab_memcg() only clears the memcg shrinker bit when the
count callback reports SHRINK_EMPTY.
Return SHRINK_EMPTY for an empty deferred split list, so the bit can be
cleared once the queue has drained.
Link: https://lore.kernel.org/20260602043453.67597-1-lance.yang@linux.dev
Signed-off-by: Lance Yang <lance.yang@linux.dev>
Reviewed-by: David Hildenbrand (Arm) <david@kernel.org>
Acked-by: Usama Arif <usama.arif@linux.dev>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kairui Song <ryncsn@gmail.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nico Pache <npache@redhat.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The deferred split queue handles cgroups in a suboptimal fashion. The
queue is per-NUMA node or per-cgroup, not the intersection. That means on
a cgrouped system, a node-restricted allocation entering reclaim can end
up splitting large pages on other nodes:
alloc/unmap
deferred_split_folio()
list_add_tail(memcg->split_queue)
set_shrinker_bit(memcg, node, deferred_shrinker_id)
for_each_zone_zonelist_nodemask(restricted_nodes)
mem_cgroup_iter()
shrink_slab(node, memcg)
shrink_slab_memcg(node, memcg)
if test_shrinker_bit(memcg, node, deferred_shrinker_id)
deferred_split_scan()
walks memcg->split_queue
The shrinker bit adds an imperfect guard rail. As soon as the cgroup has
a single large page on the node of interest, all large pages owned by that
memcg, including those on other nodes, will be split.
list_lru properly sets up per-node, per-cgroup lists. As a bonus, it
streamlines a lot of the list operations and reclaim walks. It's used
widely by other major shrinkers already. Convert the deferred split queue
as well.
The list_lru per-memcg heads are instantiated on demand when the first
object of interest is allocated for a cgroup, by calling
folio_memcg_alloc_deferred(). Add calls to where splittable pages are
created: anon faults, swapin faults, khugepaged collapse.
These calls create all possible node heads for the cgroup at once, so the
migration code (between nodes) doesn't need any special care.
[akpm@linux-foundation.org: fix build with CONFIG_TRANSPARENT_HUGEPAGE=n]
Link: https://lore.kernel.org/202605281620.lc3rtkBm-lkp@intel.com
[hannes@cmpxchg.org: fix cgroup.memory=nokmem handling]
Link: https://lore.kernel.org/ah9PGv12mqai84ES@cmpxchg.org
Link: https://lore.kernel.org/20260527204757.2544958-10-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Tested-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Acked-by: Usama Arif <usama.arif@linux.dev>
Reviewed-by: Kairui Song <kasong@tencent.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: David Hildenbrand (Arm) <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nico Pache <npache@redhat.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Cc: kernel test robot <lkp@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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alloc_anon_folio() uses a top-level if (folio) that buries the success
path four levels deep. This makes for awkward long lines and wrapping.
The next patch will add more code here, so flatten this now to keep things
clean and simple.
The next label is already there, use it for !folio.
No functional change intended.
Link: https://lore.kernel.org/20260527204757.2544958-9-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Suggested-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Acked-by: Usama Arif <usama.arif@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Dev Jain <dev.jain@arm.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: David Hildenbrand (Arm) <david@kernel.org>
Cc: Kairui Song <ryncsn@gmail.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nico Pache <npache@redhat.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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memcg_list_lru_alloc() is called every time an object that may end up on
the list_lru is created. It needs to quickly check if the list_lru heads
for the memcg already exist, and allocate them when they don't.
Doing this with folio objects is tricky: folio_memcg() is not stable and
requires either RCU protection or pinning the cgroup. But it's desirable
to make the existence check lightweight under RCU, and only pin the memcg
when we need to allocate list_lru heads and may block.
In preparation for switching the THP shrinker to list_lru, add a helper
function for allocating list_lru heads coming from a folio.
Link: https://lore.kernel.org/20260527204757.2544958-8-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: David Hildenbrand (Arm) <david@kernel.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Kairui Song <ryncsn@gmail.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nico Pache <npache@redhat.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Usama Arif <usama.arif@linux.dev>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Locking is currently internal to the list_lru API. However, a caller
might want to keep auxiliary state synchronized with the LRU state.
For example, the THP shrinker uses the lock of its custom LRU to keep
PG_partially_mapped and vmstats consistent.
To allow the THP shrinker to switch to list_lru, provide normal and
irqsafe locking primitives as well as caller-locked variants of the
addition and deletion functions.
Link: https://lore.kernel.org/20260527204757.2544958-7-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: David Hildenbrand (Arm) <david@kernel.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Reviewed-by: Liam R. Howlett (Oracle) <liam@infradead.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Kairui Song <ryncsn@gmail.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nico Pache <npache@redhat.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Usama Arif <usama.arif@linux.dev>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The MEMCG and !MEMCG paths have the same pattern. Share the code.
Link: https://lore.kernel.org/20260527204757.2544958-6-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: David Hildenbrand (Arm) <david@kernel.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Reviewed-by: Liam R. Howlett (Oracle) <liam@infradead.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Kairui Song <ryncsn@gmail.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nico Pache <npache@redhat.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Usama Arif <usama.arif@linux.dev>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Only the MEMCG variant of lock_list_lru() needs to check if there is a
race with cgroup deletion and list reparenting. Move the check to the
caller, so that the next patch can unify the lock_list_lru() variants.
Link: https://lore.kernel.org/20260527204757.2544958-5-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: David Hildenbrand (Arm) <david@kernel.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Reviewed-by: Liam R. Howlett (Oracle) <liam@infradead.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Kairui Song <ryncsn@gmail.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nico Pache <npache@redhat.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Usama Arif <usama.arif@linux.dev>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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The MEMCG and !MEMCG variants are the same. lock_list_lru() has the same
pattern when bailing. Consolidate into a common implementation.
Link: https://lore.kernel.org/20260527204757.2544958-4-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: David Hildenbrand (Arm) <david@kernel.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Reviewed-by: Liam R. Howlett (Oracle) <liam@infradead.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Kairui Song <ryncsn@gmail.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nico Pache <npache@redhat.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Usama Arif <usama.arif@linux.dev>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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skip_empty is only for the shrinker to abort and skip a list that's empty
or whose cgroup is being deleted.
For list additions and deletions, the cgroup hierarchy is walked upwards
until a valid list_lru head is found, or it will fall back to the node
list. Acquiring the lock won't fail. Remove the NULL checks in those
callers.
Link: https://lore.kernel.org/20260527204757.2544958-3-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: David Hildenbrand (Arm) <david@kernel.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Reviewed-by: Liam R. Howlett (Oracle) <liam@infradead.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Kairui Song <ryncsn@gmail.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nico Pache <npache@redhat.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Usama Arif <usama.arif@linux.dev>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Patch series "mm: switch THP shrinker to list_lru", v5.
The open-coded deferred split queue has issues. It's not NUMA-aware (when
cgroup is enabled), and it's more complicated in the callsites interacting
with it. Switching to list_lru fixes the NUMA problem and streamlines
things. It also simplifies planned shrinker work.
Patch 1 fixes a pre-existing list_lru bug where the shrinker bit is set on
the caller's memcg rather than the ancestor whose sublist the item
actually lands on after a walk-up. Standalone, backportable; the rest of
the series depends on it.
Patches 2-5 are cleanups and small refactors in list_lru code. They're
basically independent, but make the THP shrinker conversion easier.
Patch 6 extends the list_lru API to allow the caller to control the
locking scope. The THP shrinker has private state it needs to keep
synchronized with the LRU state.
Patch 7 extends the list_lru API with a convenience helper to do list_lru
head allocation (memcg_list_lru_alloc) when coming from a folio. Anon
THPs are instantiated in several places, and with the folio reparenting
patches pending, folio_memcg() access is now a more delicate dance. This
avoids having to replicate that dance everywhere.
Patch 8 flattens the alloc_anon_folio() retry loop so the next patch's
list_lru hook lands as a clean addition rather than nested deep inside an
if (folio) block.
Patch 9 finally switches the deferred_split_queue to list_lru.
This patch (of 9):
When list_lru_add() races with cgroup deletion, the shrinker bit is set on
the wrong group and lost. This can cause a shrinker run to miss the
cgroup that actually has the object.
When the passed in memcg is dead, the function finds the first non-dead
parent from the passed in memcg and adds the object there; but the
shrinker bit is set on the memcg that was passed in.
This bug is as old as the shrinker bitmap itself.
Fix it by returning the "effective" memcg from the locking function, and
have the caller use that.
Link: https://lore.kernel.org/20260527204757.2544958-1-hannes@cmpxchg.org
Link: https://lore.kernel.org/20260527204757.2544958-2-hannes@cmpxchg.org
Fixes: fae91d6d8be5 ("mm/list_lru.c: set bit in memcg shrinker bitmap on first list_lru item appearance")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Usama Arif <usama.arif@linux.dev>
Reported-by: Sashiko
Acked-by: Usama Arif <usama.arif@linux.dev>
Reviewed-by: Wei Yang <richard.weiyang@gmail.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Kairui Song <ryncsn@gmail.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nico Pache <npache@redhat.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Commit 0dfe54071d7c8 ("nodemask: Fix return values to be unsigned")
changed a number of nodemask operations that used to return int to
returning a bool instead. However, it did not update the comment block
that described these functions, leaving the documentation incorrect.
Fix the comment block to accurately describe the functions. Also fix a
typo (unsigend --> unsigned), and fix a callsite in mempolicy.c that did
not get updated during the conversion.
No functional changes intended; changes are purely cosmetic.
Link: https://lore.kernel.org/20260529202755.1846800-1-joshua.hahnjy@gmail.com
Signed-off-by: Joshua Hahn <joshua.hahnjy@gmail.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Gregory Price <gourry@gourry.net>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Ying Huang <ying.huang@linux.alibaba.com>
Cc: Yury Norov (NVIDIA) <yury.norov@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Maxime Chevallier says:
====================
net: phy: some cleanups following phy_port SFP
While posting the v11 of phy_port netlink, sashiko found some
pre-existing issues, and following the tentative fix, Nicolai found
some more :)
This is V3, with a re-ordering of the port/sfp cleanup, as well as a new
patch (patch 3) that also reorders the phy_remove() path.
====================
Link: https://patch.msgid.link/20260604092819.723505-1-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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We don't have support for PHY-driver SFP cages with the genphy code.
On top of that, it was found by sashiko that running
sfp_bus_add_upstream() for genphy deadlocks, as for genphy the PHY
probing runs under RTNL, which isn't the case for non-genphy drivers.
This problem was reproduced, and does lead to a deadlock on RTNL.
Before the blamed commit, the phy_sfp_probe() call was made by
individual PHY drivers, so there was no way to get to the SFP probing
path when using genphy.
Let's therefore only run phy_sfp_probe when not using genphy.
Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de>
Fixes: bad869b5e41a ("net: phy: Only rely on phy_port for PHY-driven SFP")
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20260604092819.723505-5-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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As reported by sashiko when looking a other patches, we need to ensure
that the downstream SFP bus gets unregistered prior to destroying the
phy_ports attached to a phy_device, as the SFP code may reference these
ports. Let's make sure we follow that ordering in phy_remove().
Fixes: 589e934d2735 ("net: phy: Introduce PHY ports representation")
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de>
Link: https://patch.msgid.link/20260604092819.723505-4-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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When phy_probe fails, let's clean the phy_ports that were successfully
added already.
Suggested-by: Nicolai Buchwitz <nb@tipi-net.de>
Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de>
Fixes: 589e934d2735 ("net: phy: Introduce PHY ports representation")
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20260604092819.723505-3-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Sashiko reported that we don't call sfp_bus_del_upstream() in the probe
failure path, so let's add it, otherwise the sfp-bus is left with a
dangling 'upstream' field, that may be used later on during SFP events.
This issue existed before the generic phylib sfp support, back when
drivers were calling phy_sfp_probe themselves.
Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de>
Fixes: 298e54fa810e ("net: phy: add core phylib sfp support")
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20260604092819.723505-2-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Sashiko flags that genlmsg_reply() always consumes the skb.
The error path calls nlmsg_free(rsp) so we can't jump directly
to it. Let's not unbind, just propagate the error to the user.
This is the typical way of handling genlmsg_reply() failures.
They shouldn't happen unless user does something silly like
calling the kernel with an already-full rcvbuf.
Reported-by: Sashiko <sashiko-bot@kernel.org>
Fixes: 170aafe35cb9 ("netdev: support binding dma-buf to netdevice")
Reviewed-by: Bobby Eshleman <bobbyeshleman@meta.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
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phonet_device_destroy() removes a phonet_device from the per-net device
list with list_del_rcu(), but frees it immediately. RCU readers walking
the same list can still hold a pointer to the object after it has been
removed, leading to a slab-use-after-free.
Use kfree_rcu(), matching the lifetime rule already used by
phonet_address_del() for the same object type.
Fixes: eeb74a9d45f7 ("Phonet: convert devices list to RCU")
Cc: stable@vger.kernel.org
Signed-off-by: Santosh Kalluri <santosh.kalluri129@gmail.com>
Acked-by: Rémi Denis-Courmont <remi@remlab.net>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
napi_disable() is not idempotent and calling it on an already-disabled
or unenabled NAPI context will cause the kernel to spin indefinitely
waiting for the NAPI_STATE_SCHED bit to clear.
In mal_remove(), napi_disable() is called unconditionally. If no MACs were
registered, NAPI was never enabled. Also, if they were registered but
subsequently unregistered, NAPI was already disabled in
mal_unregister_commac(). In either case, calling napi_disable() causes
the kernel to hang upon module removal.
Fix this by only calling napi_disable() in mal_remove() if the commac list
is not empty (which implies NAPI is enabled).
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Link: https://patch.msgid.link/20260603230821.5619-1-rosenp@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Clear MAL descriptor rings with explicit field stores instead of
memset(). The descriptor rings are carved from MAL coherent DMA memory,
which may be mapped uncached on 32-bit powerpc. The optimized memset()
path can use dcbz there and trigger an alignment warning.
Use WRITE_ONCE() for each field to prevent the compiler from merging
the stores back into a memset() call.
The skb tracking arrays remain ordinary CPU memory and still use memset().
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Link: https://patch.msgid.link/20260603230754.5535-1-rosenp@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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The driver was using devm_register_netdev() which causes unregister_netdev()
to be deferred until the devres cleanup phase, which runs after emac_remove()
returns. This creates a use-after-free window where:
1. emac_remove() is called, which tears down hardware (cancels work, detaches
modules, unregisters from MAL)
2. emac_remove() returns
3. devres cleanup runs and finally calls unregister_netdev()
During step 3, the network stack might still process packets, triggering
emac_irq(), emac_poll(), or other handlers that access now-freed hardware
resources (dev->emacp, dev->mal, etc.).
Fix this by replacing devm_register_netdev() with manual register_netdev()
and calling unregister_netdev() at the beginning of emac_remove(), before
any hardware teardown. This ensures the network device is fully stopped and
unregistered before hardware resources are released.
The change is safe because:
- dev->ndev is assigned very early in probe (before any error paths that
could bypass emac_remove)
- platform_set_drvdata() is only called after successful registration, so
emac_remove() only runs for fully registered devices
- unregister_netdev() is idempotent and safe to call on any registered device
Fixes: a4dd8535a527 ("net: ibm: emac: use devm for register_netdev")
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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platform_get_irq() returns a negative errno on failure.
Commit c4f5d0454cab5 moved the platform_get_irq() calls and explicitly
removed the error checks that were previously present, claiming
devm_request_irq() can handle it. However, a negative IRQ number
passed to devm_request_irq() fails with -EINVAL instead of
propagating the real error from platform_get_irq().
Restore the missing error checks with proper errno propagation.
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260603211734.30750-1-rosenp@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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mlx4_init_user_cqes() fills a scratch buffer with the CQE
initialization pattern and then copies from that buffer to userspace.
In the single-copy path, the copy length is array_size(entries,
cqe_size), but the scratch buffer is allocated with PAGE_SIZE. GCC 10
does not carry the branch invariant strongly enough through the object
size checks and falsely triggers __bad_copy_from().
Size the scratch buffer to the actual copy length for the active path,
keep array_size() for the single-copy case, and retain a WARN_ON_ONCE()
guard for the PAGE_SIZE invariant before allocating the buffer.
Fixes: f69bf5dee7ef ("net/mlx4: Use array_size() helper in copy_to_user()")
Signed-off-by: Yao Sang <sangyao@kylinos.cn>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Sashiko points out this has gotten out of order, the mutex could still be
in use through the dmabuf invalidation callbacks. Don't destroy any of the
pages content until the dmabuf is fully detached.
Fixes: 71db84a092c3 ("iommufd: Add DMABUF to iopt_pages")
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
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skb_gro_receive_list() calls skb_pull(skb, skb_gro_offset(skb)) without
first ensuring the data is in the linear area via pskb_may_pull(). When
the skb arrives via napi_gro_frags(), skb_headlen can be 0 (all data in
page fragments) while skb_gro_offset is non-zero (after IP+TCP header
parsing). The skb_pull() then decrements skb->len by skb_gro_offset
but skb->data_len stays unchanged, hitting BUG_ON(skb->len < skb->data_len)
in __skb_pull().
The UDP fraglist GRO path already contains this guard at
udp_offload.c:749. Adding it to skb_gro_receive_list() itself provides
centralized protection for all callers (TCP, UDP, and any future
protocols), and ensures the precondition of skb_pull() is satisfied
before it is called.
On pskb_may_pull() failure, set NAPI_GRO_CB(skb)->flush = 1 so the
skb is not held as a new GRO head and is instead delivered through the
normal receive path, matching the UDP handling.
Fixes: 8d95dc474f85 ("net: add code for TCP fraglist GRO")
Reported-by: HanQuan <eilaimemedsnaimel@gmail.com>
Reported-by: MingXuan <bwnie0730@outlook.com>
Signed-off-by: HanQuan <eilaimemedsnaimel@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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pdsc_teardown() frees DMA buffers but does not disable bus mastering,
leaving the device able to perform DMA after the buffers are freed.
This can lead to use-after-free if the device writes to freed memory.
Add pci_clear_master() to pdsc_teardown() to disable bus mastering
before freeing resources, ensuring all DMA is quiesced.
Add pci_set_master() to pdsc_setup() to re-enable bus mastering,
which is needed for the firmware recovery path since pdsc_teardown()
now disables it.
Signed-off-by: Nikhil P. Rao <nikhil.rao@amd.com>
Link: https://patch.msgid.link/20260604213637.3844317-1-nikhil.rao@amd.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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dma_buf_unpin() requires the caller to hold the exporter's dma_resv
lock:
void dma_buf_unpin(struct dma_buf_attachment *attach)
{
...
dma_resv_assert_held(dmabuf->resv);
...
}
iopt_release_pages() calls dma_buf_unpin() without taking that lock,
so every iommufd_ioas_destroy()/iommufd_ioas_unmap() that releases
the last reference on a DMABUF-backed iopt_pages triggers a WARN.
This was hit while running tools/testing/selftests/iommu/iommufd:
WARNING: drivers/dma-buf/dma-buf.c:1137 at dma_buf_unpin+0x62/0x70
RIP: 0010:dma_buf_unpin+0x62/0x70
Call Trace:
<TASK>
dma_buf_unpin+0x62/0x70
iopt_release_pages+0xe4/0x190
iopt_unmap_iova_range+0x1c7/0x290
iopt_unmap_all+0x1a/0x30
iommufd_ioas_destroy+0x1d/0x50
iommufd_fops_release+0x93/0x150
__fput+0xfc/0x2c0
__x64_sys_close+0x3d/0x80
do_syscall_64+0x65/0x180
</TASK>
Take the dma_resv lock around dma_buf_unpin() in iopt_release_pages(),
matching the iopt_map_dmabuf() convention. dma_buf_detach() acquires the
reservation lock internally, so it must remain outside the locked region.
Fixes: 8c5f9645c389 ("iommufd: Add dma_buf_pin()")
Link: https://patch.msgid.link/r/20260526111034.4079-1-Ankit.Soni@amd.com
Reported-by: Ankit Soni <Ankit.Soni@amd.com>
Signed-off-by: Ankit Soni <Ankit.Soni@amd.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
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Kuniyuki Iwashima says:
====================
ip6mr: No RTNL for RTNL_FAMILY_IP6MR rtnetlink.
This series is the IPv6 version of
https://lore.kernel.org/netdev/20260228221800.1082070-1-kuniyu@google.com/
and removes RTNL from ip6mr rtnetlink handlers.
After this series, there are a few RTNL left in net/ipv6/ip6mr.c
and such users will be converted to per-netns RTNL in another
series.
Patch 1 extends the ipmr selftest to exercise most of the RTNL
paths in net/ipv6/ipmr.c
Patch 2 - 6 converts RTM_GETROUTE handlers to RCU.
Patch 7 removes struct fib_dump_filter.rtnl_held.
Patch 8 use RCU for mr_table for CONFIG_IPV6_MROUTE_MULTIPLE_TABLES=n
for ->exit_rtnl().
Patch 9 move fib_rules_unregister() to ->exit()
Patch 10 - 12 converts ->exit_batch() to ->exit_rtnl() to
save one RTNL in cleanup_net().
Patch 13 removes unnecessary RTNL during setup_net() failure.
Patch 14 drops RTNL for MRT6_(ADD|DEL)_MFC(_PROXY)?.
Patch 15 misc clean up
v2: https://lore.kernel.org/20260410211726.1668756-1-kuniyu@google.com
v1: https://lore.kernel.org/20260407212001.2368593-1-kuniyu@google.com
====================
Link: https://patch.msgid.link/20260604224712.3209821-1-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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net->ipv6.ip6mr_notifier_ops and net->ipv6.ipmr_seq are used
only in net/ipv6/ip6mr.c.
Let's move these definitions under CONFIG_IPV6_MROUTE.
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260604224712.3209821-16-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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ip6mr does not have rtnetlink interface for MFC unlike ipmr,
which uses dev_get_by_index_rcu() to set struct mfcctl.mfcc_parent.
ip6mr_mfc_add() and ip6mr_mfc_delete() are called under RTNL
from ip6_mroute_setsockopt() only.
There are no RTNL dependant, but ip6_mroute_setsockopt() reuses
RTNL just for mrt->mfc_hash and mrt->mfc_cache_list.
Let's replace RTNL with a new per-netns mutex.
Later, ip6mr_notifier_ops and ipmr_seq will be moved under
CONFIG_IPV6_MROUTE.
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260604224712.3209821-15-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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When ip6mr_free_table() is called from ip6mr_rules_init() or
ip6mr_net_init(), the netns is not yet published.
Thus, no device should have been registered, and
mroute_clean_tables() will not call mif6_delete(), so
unregister_netdevice_many() is unnecessary.
unregister_netdevice_many() does nothing if the list is empty,
but it requires RTNL due to the unconditional ASSERT_RTNL()
at the entry of unregister_netdevice_many_notify().
Let's remove unnecessary RTNL and ASSERT_RTNL() and instead
add WARN_ON_ONCE() in ip6mr_free_table().
Note that we use a local list for the new WARN_ON_ONCE() because
dev_kill_list passed from ip6mr_rules_exit_rtnl() may have some
devices when other ops->init() fails after ipmr durnig setup_net().
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260604224712.3209821-14-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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ip6mr_net_ops uses ->exit_batch() to acquire RTNL only once
for dying network namespaces.
ip6mr does not depend on the ordering of ->exit_rtnl() and
->exit_batch() of other pernet_operations (unlike fib_net_ops).
Once ip6mr_free_table() is called and all devices are
queued for destruction in ->exit_rtnl(), later during
NETDEV_UNREGISTER, ip6mr_device_event() will not see anything
in vif table and just do nothing.
Let's convert ip6mr_net_exit_batch() to ->exit_rtnl().
We will remove RTNL and unregister_netdevice_many() in
ip6mr_rules_init().
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260604224712.3209821-13-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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This is a prep commit to convert ip6mr_net_exit_batch() to
->exit_rtnl().
Let's move unregister_netdevice_many() in ip6mr_free_table()
to its callers.
Now ip6mr_rules_exit() can do batching all tables per netns.
Note that later we will remove RTNL and unregister_netdevice_many()
in ip6mr_rules_init().
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260604224712.3209821-12-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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This is a prep commit to convert ip6mr_net_exit_batch() to
->exit_rtnl().
Let's move unregister_netdevice_many() in mroute_clean_tables()
to its callers.
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260604224712.3209821-11-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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fib_rules_unregister() removes ops from net->rules_ops under
spinlock, calls ops->delete() for each rule, and frees the ops.
ip6mr_rules_ops_template does not have ->delete(), and any
operation does not require RTNL there.
Let's move fib_rules_unregister() from ip6mr_rules_exit() to
ip6mr_net_exit().
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260604224712.3209821-10-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Since default_device_exit_batch() is called after ->exit_rtnl(),
idev->mc_ifc_work could finally call mroute6_is_socket() under RCU
while ->exit_rtnl() is running. [0]
With CONFIG_IPV6_MROUTE_MULTIPLE_TABLES=n, ip6mr_fib_lookup() does
not check if net->ipv6.mrt6 is NULL. If ip6mr_net_exit_batch()
set net->ipv6.mrt6 to NULL and freed it, the mrt->mroute_sk access
could result in null-ptr-deref or use-after-free.
Let's prepare for that situation by applying RCU rule to ip6mr
table similarly.
!check_net(net) is added in ip6mr_cache_unresolved() and
mroute_clean_tables() to synchronise the two by mfc_unres_lock
so that ip6mr_cache_unresolved() will not queue skb after
mroute_clean_tables() purged &mrt->mfc_unres_queue.
rcu_read_lock() in reg_vif_xmit() is moved up to cover
ip6mr_fib_lookup() as with ipmr.
Link: https://lore.kernel.org/netdev/20260407184202.34cfe2d6@kernel.org/ #[0]
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260604224712.3209821-9-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Commit 22e36ea9f5d7 ("inet: allow ip_valid_fib_dump_req() to
be called with RTNL or RCU") introduced the rtnl_held field in
struct fib_dump_filter to switch __dev_get_by_index() and
dev_get_by_index_rcu() depending on the caller's context.
This field served as an interim measure while we were incrementally
converting all callers of ip_valid_fib_dump_req() to RCU.
Now that all users (IPv4, IPv6, ipmr, ip6mr, and MPLS) have
been converted to RCU, the field is no longer necessary.
Let's remove it.
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260604224712.3209821-8-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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ip6mr_rtm_dumproute() calls mr_table_dump() or mr_rtm_dumproute(),
and mr_rtm_dumproute() finally calls mr_table_dump().
mr_table_dump() calls the passed function, _ip6mr_fill_mroute().
_ip6mr_fill_mroute() is a wrapper for ip6mr_fill_mroute() to cast
struct mr_mfc * to struct mfc6_cache *.
ip6mr_fill_mroute() can already be called safely under RCU.
Let's convert ip6mr_rtm_dumproute() to RCU.
Now there is no user of the rtnl_held field in struct
fib_dump_filter, and the next patch will remove it.
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260604224712.3209821-7-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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ip6mr_rtm_getroute() calls __ip6mr_get_table(), ip6mr_cache_find(),
and ip6mr_fill_mroute().
Once created, struct mr_table is not freed until netns dismantle,
so it's safe under RCU.
ip6mr_cache_find() iterates mrt->mfc_hash with rhl_for_each_entry_rcu().
struct mr_mfc is freed with call_rcu(), so this is also safe under
RCU.
ip6mr_fill_mroute() calls mr_fill_mroute(), which properly uses
RCU helpers.
Let's call them under RCU and register ip6mr_rtm_getroute() with
RTNL_FLAG_DOIT_UNLOCKED.
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260604224712.3209821-6-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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