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Patch series "mm/vmscan: reduce lru_lock contention via vmstat-derived
scan-balance cost", v5.
The anon/file scan balance heuristic in get_scan_count() is fed by two
scalars in struct lruvec (anon_cost, file_cost) that every reclaim
producer updates under lruvec->lru_lock. The cost-recording work itself
is trivial, but it both contends for and contributes to contention on
lru_lock - which is often a contention point on memory-pressured
workloads. Specifically:
- shrink_inactive_list() re-acquires lru_lock at function exit just
to call lru_note_cost_unlock_irq().
- shrink_active_list() does the same after rotation accounting.
- workingset_refault() takes folio_lruvec_lock_irq() purely to
record the refault cost.
- prepare_scan_control() snapshots anon_cost/file_cost under
lru_lock.
- lru_note_cost_unlock_irq() itself walks parent_lruvec() and
re-acquires lru_lock on every ancestor, multiplying the cost
of every update by memcg-hierarchy depth.
This series removes those producer-side acquisitions entirely. The
rotation inputs become per-LRU PGROTATE_{ANON,FILE} vmstat counters.
NR_VMSCAN_WRITE already captures reclaim-driven pageout at writeout();
charge it through lruvec_stat_mod_folio() so it is available per lruvec
and aggregated through the memcg hierarchy. Reclaim does not submit
filesystem folios for writeback from this path, so pageout contributes
only to anon cost. WORKINGSET_RESTORE_* already captures the refault
input.
PGROTATE_* are also useful independently of scan balancing. They are
cumulative base-page events, not unique-page counts. Classic inactive
reclaim records scan work that does not produce immediate reclaim or
demotion, while active reclaim records referenced executable file folios
retained on the active list. MGLRU records initially isolated pages that
remain unreclaimed after its retry passes. Read alongside pgscan_* and
pgsteal_*, their deltas identify which LRU type is consuming reclaim CPU
without producing immediate yield. Unlike the existing pgrotated event,
they do not imply a move to the inactive-list tail.
prepare_scan_control() reads the raw cost signals without lru_lock:
anon = PGROTATE_ANON +
(NR_VMSCAN_WRITE + WORKINGSET_RESTORE_ANON) * SWAP_CLUSTER_MAX
file = PGROTATE_FILE +
WORKINGSET_RESTORE_FILE * SWAP_CLUSTER_MAX
It folds the deltas into a per-lruvec accumulator. A dedicated per-lruvec
cost_lock, not touched by isolate_lru_folios(), move_folios_to_lru(), or
folio_add_lru(), serialises the accumulator RMW and the lrusize/4 halving
check. Hierarchy aggregation is implicit in rstat propagation, so the
parent_lruvec() walk and the lru_reparent_memcg() cost-splice both
disappear.
Moving accumulation and decay to the reclaim side also improves the cost
model across reclaim gaps. With producer-side decay, events that happen
while reclaim is idle still age each other before reclaim ever samples the
costs. If a workload refaults a large anon set and then a smaller file
set before reclaim runs again, the later file activity can age the earlier
anon activity out of the cost model. The new scheme observes the whole
between-reclaim delta and decays anon and file proportionally, so the
scan-balance history better represents what happened since the last
reclaim pass.
Trade-offs:
- Cost reads see rstat-aggregated values that can lag until periodic /
reader-triggered flushing.
- Per-lruvec footprint grows by 4 unsigned longs + a spinlock (a
struct lru_cost { count, last_rotated, last_io } per side), which
is a small cost.
- NR_VMSCAN_WRITE now also updates the folio's lruvec/memcg stat,
adding memcg stat accounting to the reclaim writeout path while
preserving the existing node-level total.
== Numbers ==
Tested on a 176-core, 256 GB host. The benchmark drives sustained
swap-out/refault inside a tight memcg using vm-scalability/usemem:
usemem -n 16 --prealloc --prefault --random $((256*1024*1024))
run inside a two-level memcg with memory.max=512M on the leaf (4 GB anon
working set has to fit in 512 MB -> continuous shrink_inactive_list +
workingset_refault). A 16 GB swap file is used. Measurement is a 30 s
`perf lock record -a` window over otherwise-idle hardware.
Workload rates are identical on both kernels (the bench drives the same
memory pressure):
baseline patched delta
pgscan_direct / s 172,662 171,817 ~0%
pgsteal_direct / s 67,162 66,306 ~0%
workingset_refault_anon / s
40,696 39,830 ~0%
perf lock contention (total wait per 30 s window):
Lock Name Before After % change
shrink_lruvec+0x770 722.84 ms 0 -100% (eliminated)
(= lru_note_cost_unlock_irq)
workingset_refault+0x167 385.26 ms 0 -100% (eliminated)
(= lru_note_cost_refault)
shrink_node+0x4ad 689.43 ms 26.95 ms -96%
shrink_active_list 208.34 ms 15.97 ms -92%
lru_add_drain_cpu+0x34 1.96 s 917.71 ms -53%
Total LRU lock wait ~4.23 s ~1.66 s -61%
The two specific contention sites the patch removes (shrink_lruvec+0x770 =
lru_note_cost_unlock_irq; workingset_refault+0x167 =
lru_note_cost_refault) are completely absent from the patched
perf-lock-contention output. Secondary reductions in shrink_node,
shrink_active_list, lru_add_drain_cpu and pgrefill/pgactivate look like
knock-on effects from removing the cost-recording overhead and the
parent_lruvec walk.
The remaining ~1.66 s of LRU lock wait on the patched kernel is dominated
by the per-CPU pagevec drain (lru_add_drain_cpu) and the main reclaim path
in shrink_lruvec.
The numbers above can be reproduced using the script in [1].
This patch (of 3):
lruvec_page_state(), node_page_state(), and global_node_page_state() all
clamp negative reads to zero on CONFIG_SMP so that a transient per-CPU
delta skew presents as zero pages rather than as a garbage unsigned value.
This is the right behaviour for non-monotonic page-count readers.
It is however incorrect for callers that snapshot a monotonically-
incremented event counter and compute a delta from two samples. Once the
underlying signed long wraps past LONG_MAX, the clamped read drops to zero
while the previously-recorded snapshot still holds the pre-wrap value; the
unsigned subtraction then underflows into a ~2^31 spurious delta for
32-bit architecture and corrupts the caller's accumulator.
Add non-clamping siblings that return the underlying state value cast to
unsigned long:
global_node_page_state_monotonic()
node_page_state_monotonic()
lruvec_page_state_monotonic()
With both samples read via the _monotonic variant, unsigned modular
subtraction stays correct across a signed-long wraparound as long as the
true growth between two samples fits in unsigned long (< 2^32 on 32-bit, <
2^64 on 64-bit); the 32-bit bound is the practically-reachable one that
motivates this helper.
The variants are only safe for monotonically-incremented counters.
Non-monotonic page-count readers must keep using the existing clamped
helpers so transient negative reads still present as zero.
This is a prerequisite for a later patch which replaces the producer-side
anon_cost/file_cost accumulators with a read-side accumulator in
prepare_scan_control() that samples monotonic per-LRU vmstat counters
(PGROTATE_*, NR_VMSCAN_WRITE, WORKINGSET_RESTORE_*) via
lruvec_page_state_monotonic() and folds their unsigned modular deltas into
lruvec->cost[].count.
Link: https://lore.kernel.org/20260727162550.2032-1-usama.arif@linux.dev
Link: https://lore.kernel.org/20260727162550.2032-2-usama.arif@linux.dev
Link: https://gist.github.com/uarif1/a4eb33a86c5b2d7bbc55b42f0956e884 [1]
Signed-off-by: Usama Arif <usama.arif@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Chris Li <chrisl@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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sc_swappiness() had two separate definitions depending on CONFIG_MEMCG.
The !CONFIG_MEMCG variant simply returned vm_swappiness, ignoring the
proactive_swappiness value passed through scan_control. This caused the
swappiness parameter written to /sys/devices/system/node/nodeX/reclaim to
have no effect when CONFIG_MEMCG is disabled.
Fix this by consolidating sc_swappiness() into a single definition that
checks sc->proactive_swappiness first, then falls back to
mem_cgroup_swappiness() which already handles both CONFIG_MEMCG and
!CONFIG_MEMCG.
Before fix (swappiness=max ignored, mostly file pages reclaimed):
# cat /proc/sys/vm/swappiness
60
# cat /proc/vmstat | grep pgsteal
pgsteal_kswapd 0
pgsteal_direct 0
pgsteal_khugepaged 0
pgsteal_proactive 1840
pgsteal_anon 25
pgsteal_file 1815
# echo "64M swappiness=max" > /sys/devices/system/node/node0/reclaim
# cat /proc/vmstat | grep pgsteal
pgsteal_kswapd 0
pgsteal_direct 0
pgsteal_khugepaged 0
pgsteal_proactive 18013
pgsteal_anon 337
pgsteal_file 17676
After fix (swappiness=max honored, anon pages reclaimed as expected):
# cat /proc/vmstat | grep pgsteal
pgsteal_kswapd 0
pgsteal_direct 0
pgsteal_khugepaged 0
pgsteal_proactive 0
pgsteal_anon 0
pgsteal_file 0
# echo "64M swappiness=max" > /sys/devices/system/node/node0/reclaim
# cat /proc/vmstat | grep pgsteal
pgsteal_kswapd 0
pgsteal_direct 0
pgsteal_khugepaged 0
pgsteal_proactive 16283
pgsteal_anon 16283
pgsteal_file 0
Link: https://lore.kernel.org/20260723032434.2016749-3-ridong.chen@linux.dev
Fixes: b980077899ea ("mm: introduce per-node proactive reclaim interface")
Signed-off-by: Ridong Chen <chenridong@xiaomi.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Barry Song <baohua@kernel.org>
Acked-by: Qi Zheng <qi.zheng@linux.dev>
Tested-by: Song Hu <husong@kylinos.cn>
Reviewed-by: Song Hu <husong@kylinos.cn>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Chris Li <chrisl@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Cc: <stable@vger.kernel.org> [6.17+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "mm: vmscan: fix node reclaim ignoring swappiness parameter",
v4.
The per-node proactive reclaim interface
(/sys/devices/system/node/nodeX/reclaim) accepts a swappiness parameter,
but it is silently ignored when CONFIG_MEMCG is disabled. The root cause
is that sc_swappiness() has separate implementations for CONFIG_MEMCG and
!CONFIG_MEMCG, and the latter never checks proactive_swappiness.
Patch 1 moves mem_cgroup_swappiness() and vm_swappiness out of the public
include/linux/swap.h into the mm-private mm/swap.h, and makes the helper
handle both CONFIG_MEMCG and !CONFIG_MEMCG in a single inline function.
This is a prerequisite for unifying sc_swappiness().
Patch 2 consolidates sc_swappiness() into a single definition that works
regardless of CONFIG_MEMCG, fixing the node reclaim swappiness bug.
This patch (of 2):
The per-memcg swappiness knob is v1-only; v2 always uses global
vm_swappiness and ignores the per-cgroup field.
Both mem_cgroup_swappiness() and vm_swappiness are only used within mm/
(memcontrol.c, memcontrol-v1.c, vmscan.c), so move them out of the public
include/linux/swap.h into the mm-private mm/swap.h. This keeps unrelated
declarations out of include/linux/swap.h.
Guard memcg->swappiness with CONFIG_MEMCG_V1 as well, so v2-only
kernels drop the unused field.
No functional change for v1; v2-only kernels drop the unused field.
Link: https://lore.kernel.org/20260723032434.2016749-1-ridong.chen@linux.dev
Link: https://lore.kernel.org/20260723032434.2016749-2-ridong.chen@linux.dev
Signed-off-by: Ridong Chen <chenridong@xiaomi.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Barry Song <baohua@kernel.org>
Reviewed-by: Song Hu <husong@kylinos.cn>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Chris Li <chrisl@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Cc: Qi Zheng <qi.zheng@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Classical LRU protects mapped executable file folios through commit
8cab4754d24a0 ("vmscan: make mapped executable pages the first class
citizen") and commit c909e99364c8 ("vmscan: activate executable pages
after first usage"), giving executable code a better chance to stay in
memory, avoiding IO thrashing and improving workload performance.
However, MGLRU's protection of mapped executable file folios is less
reliable. Although shrink_folio_list() checks references, the access flag
of mapped executable file folios may have already been checked and cleared
by lru_gen_look_around() or walk_mm(). Additionally, folio_update_gen()
or lru_gen_set_refs() only sets the 'PG_referenced' flag for mapped
executable file folios, which causes shrink_folio_list() to ignore the
first usage of these mapped executable file folios and reclaim them
easily.
Follow the classical LRU's logic, promoting mapped executable file folios
after their first usage in folio_update_gen() and lru_gen_set_refs(),
giving executable code a better chance to stay in memory.
On my 32-core Arm machine, with the memcg limit set to 2G, running 'make
-j32' to build kernel showed some improvement in sys time.
base patched
9248.543s 7861.579s
Link: https://lore.kernel.org/f57d94b1d85bb3d620d89bb739128f0d929bf9c6.1784509721.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Axel Rasmussen <axelrasmussen@google.com>
Cc: Barry Song <baohua@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Harry Yoo <harry@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Kairui Song <kasong@tencent.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: Rik van Riel <riel@surriel.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Add a helper to identify file-backed executable folios to avoid duplicate
code.
No functional changes.
Link: https://lore.kernel.org/2ee74f9f98ac45a2f0db0ceb018e086bdb671d17.1784509721.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Axel Rasmussen <axelrasmussen@google.com>
Reviewed-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Kairui Song <kasong@tencent.com>
Reviewed-by: Barry Song <baohua@kernel.org>
Cc: Harry Yoo <harry@kernel.org>
Cc: Jann Horn <jannh@google.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: Rik van Riel <riel@surriel.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "promote mapped executable folios after first usage for
MGLRU", v4.
Now MGLRU's protection of mapped executable file folios is less reliable.
Follow the classical LRU's logic, promoting mapped executable file folios
after their first usage to give executable code a better chance to stay in
memory and improve workload performance (See patch 2 for more details).
This patch (of 3):
Replace use of the legacy vm_flags_t flags with vma_flags_t values for
folio_referenced() and related logic. This is also a preparation for the
following changes.
No functional changes.
Link: https://lore.kernel.org/cover.1784509721.git.baolin.wang@linux.alibaba.com
Link: https://lore.kernel.org/2bd39e16ec19e3e3c4716aa9a1a25775c26cac57.1784509721.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Barry Song <baohua@kernel.org>
Reviewed-by: Kairui Song <kasong@tencent.com>
Reviewed-by: Axel Rasmussen <axelrasmussen@google.com>
Cc: Harry Yoo <harry@kernel.org>
Cc: Jann Horn <jannh@google.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: Rik van Riel <riel@surriel.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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kmemleak_scan() can run for ages on large debug kernels. It was
causing some soft-lockups which I got fixed with commit
3175fcfec8b16baeb ("mm/kmemleak: avoid soft lockup when scanning task
stacks") with our beloved cond_resched().
I've got the fix above deployed in the Meta fleet, and now I am seeing:
INFO: rcu_tasks detected stalls on tasks:
task:kmemleak state:R ... nvcsw: 274/274 holdout: 1 idle_cpu: -1/3
scan_block
scan_gray_list
kmemleak_scan
and, worse, blocks the callers waiting on that grace period. Here a BPF
struct_ops map free, which waits via synchronize_rcu_mult(call_rcu,
call_rcu_tasks), is stuck long enough to also trip the hung task check:
INFO: task kworker/...:bpf_map_free_deferred blocked for 122 seconds
__wait_rcu_gp
bpf_struct_ops_map_free
Then I've learned that cond_resched() is not an RCU-tasks quiescent
state, so, we need to use stronger primitives.
Use cond_resched_tasks_rcu_qs() at the scan reschedule points so the scan
reports an RCU-tasks quiescent state as it proceeds.
Inspired by commit b96285e10aad ("tracing: Have osnoise_main() add a
quiescent state for task rcu").
Link: https://lore.kernel.org/20260720-kmemleak_rcu_task-v1-1-5b460ade777d@debian.org
Fixes: c4b28963fd79 ("mm/kmemleak: rely on rcu for task stack scanning")
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: SJ Park <sj@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Breno Leitao <leitao@debian.org>
Cc: Puranjay Mohan <puranjay@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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While maintaining anonymous page offsets for VMAs has no impact for most
merge cases, it does impact MAP_PRIVATE-mapped file-backed mappings which
happen to have matching page offset but not matching anonymous page
offset.
Assert this behaviour by attempting to map an unfaulted MAP_PRIVATE-memfd
region with a faulted one with compatible file page offsets but
incompatible anonymous page offsets.
Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-16-c21581c0c3c8@kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Deucher <alexander.deucher@amd.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Chris Li <chrisl@kernel.org>
Cc: Christan König <christian.koenig@amd.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Gregory Price (Meta) <gourry@gourry.net>
Cc: Harry Yoo <harry@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huang Ray <Ray.Huang@amd.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Namhyung kim <namhyung@kernel.org>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Steven Price <steven.price@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Thomas Zimemrmann <tzimmermann@suse.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Now we have introduced the VMA anonymous page offset attribute and update
it when VMAs are manipulated, update VMA merge tests to assert that the
anonymous page offset is as expected.
Also update instances where we could use vma_start_pgoff() to do so.
Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-15-c21581c0c3c8@kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Deucher <alexander.deucher@amd.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Chris Li <chrisl@kernel.org>
Cc: Christan König <christian.koenig@amd.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Gregory Price (Meta) <gourry@gourry.net>
Cc: Harry Yoo <harry@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huang Ray <Ray.Huang@amd.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Namhyung kim <namhyung@kernel.org>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Steven Price <steven.price@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Thomas Zimemrmann <tzimmermann@suse.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Currently anonymous folios belonging to CoW'd MAP_PRIVATE file-backed
mappings are indexed by their page offset within the file in which they
were originally mapped.
This differs from anonymous folios belonging to pure anon mappings which
are indexed by their anonymous page offset (the address at which they'd
belong in the VMA when first faulted).
This change fixes this inconsistency, always indexing anonymous folios by
their anonymous page offset regardless of the VMA to which they belong.
The foundations have been laid such that we need only switch this
functionality on such by:
* Using linear_anon_page_index() in __folio_set_anon() to assign the
folio's index to the anonymous linear index rather than the file-backed
one.
* Otherwise using linear_anon_page_index() in all instances where
anonymous folios are being referenced or manipulated.
* Replacing vma_address() with vma_filebacked_address() or
vma_anon_address() as appropriate.
* Updating the merging logic to check that anonymous page offsets are
aligned as well as filebacked ones for MAP_PRIVATE file-backed VMAs,
introducing needs_adjacent_anon_pgoff() to figure out when this is
required.
* Updating linear_folio_page_index() to invoke linear_anon_page_index()
if the folio is anonymous.
* Updating vma_address_end() to use the VMA's anonymous page offset when
pvmw->pgoff is anonymous.
* Correcting folio_within_range() to use anonymous page offset for
anonymous folios.
This will have no impact on merging of anonymous VMAs, whose page offset
and anonymous page offset are identical, nor will it impact shared
file-backed VMAs, which will continue to be merged based on the
file-backed page offset.
However, MAP_PRIVATE file-backed mappings must now be aligned on anonymous
page offset as well.
In most instances this should have no impact on merging of file-backed
mappings, which are usually not merged all that often, let alone
MAP_PRIVATE mapped ones, and rarely remapped and faulted before being
moved back in place (the case in which a merge may now fail).
One subtle impact of this change is in NUMA interleaving - since commit
88c91dc58582 ("mempolicy: migration attempt to match interleave nodes"),
migration heuristically tries to maintain interleaving behaviour matching
the policy using folio indices.
When doing migration of CoW'd MAP_PRIVATE-file backed ranges, the 'base'
upon which the interleaving behaviour is performed will vary for these
ranges. However the commit notes that ranges spanning multiple VMAs will
already cause varying bases, and that this is an acceptable approximation.
It is very unlikely real world use-cases will be impacted by this
(MAP_PRIVATE file-backed mappings are already an edge case), and all that
will happen is that such ranges will cause interleaving to be rotated over
the CoW'd range, with little to no impact.
This commit lays the foundations for future scalable CoW work which needs
to track some remaps, meaning that most remap tracking can be avoided, and
in nearly all cases the anonymous page offset will be able to be used to
quickly find the VMA in an mm.
Note that the need_rmap_locks check doesn't need to be updated, as any
remapping will offset both the anonymous and file-backed page offset, so
it suffices to check only one.
Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-14-c21581c0c3c8@kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Deucher <alexander.deucher@amd.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Chris Li <chrisl@kernel.org>
Cc: Christan König <christian.koenig@amd.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Gregory Price (Meta) <gourry@gourry.net>
Cc: Harry Yoo <harry@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huang Ray <Ray.Huang@amd.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Namhyung kim <namhyung@kernel.org>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Steven Price <steven.price@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Thomas Zimemrmann <tzimmermann@suse.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Rather than having to figure out the page index to use using
linear_page_index(), calculate it using PFN.
This is a more natural fit as the linear page index is immaterial to
determining the folio page index.
Derive the page index from the offset between migration entry PFN and
folio PFN - pvmw.pfn (set via DEFINE_FOLIO_VMA_WALK() which uses
folio_pfn() to obtain it).
Additionally remove a not so useful comment and clean the code layout up.
No functional change intended.
Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-13-c21581c0c3c8@kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Suggested-by: David Hildenbrand (Arm) <david@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Deucher <alexander.deucher@amd.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Chris Li <chrisl@kernel.org>
Cc: Christan König <christian.koenig@amd.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Gregory Price (Meta) <gourry@gourry.net>
Cc: Harry Yoo <harry@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huang Ray <Ray.Huang@amd.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Namhyung kim <namhyung@kernel.org>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Steven Price <steven.price@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Thomas Zimemrmann <tzimmermann@suse.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
This function does not need to accept a page and requiring it to is
unnecessary and misleading.
make_[writable, readable]_device_private_entry() must be passed a
PMD-aligned PFN as they immediately used to obtain a softleaf PMD entry
and the same argument applies to folio_add_[anon, file]_rmap_pmd().
While we are here, update a VM_BUG_ON() to a VM_WARN_ON_ONCE().
No functional change intended.
Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-12-c21581c0c3c8@kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Deucher <alexander.deucher@amd.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Chris Li <chrisl@kernel.org>
Cc: Christan König <christian.koenig@amd.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Gregory Price (Meta) <gourry@gourry.net>
Cc: Harry Yoo <harry@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huang Ray <Ray.Huang@amd.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Namhyung kim <namhyung@kernel.org>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Steven Price <steven.price@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Thomas Zimemrmann <tzimmermann@suse.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
vma_address_end() is a confusing function with a lot of moving parts so
clean it up prior to extending it for anon page indexed mappings.
Const-ify some variables and establish pgoff_vma_start and pgoff_end
variables to clearly identify the page offset for the start of the VMA and
the end of the page offset range specified by the page walk.
This simplifies the function significantly and lays the groundwork for a
future change to update this function to account for anonymously page
indexed folios.
No functional change intended.
Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-11-c21581c0c3c8@kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Deucher <alexander.deucher@amd.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Chris Li <chrisl@kernel.org>
Cc: Christan König <christian.koenig@amd.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Gregory Price (Meta) <gourry@gourry.net>
Cc: Harry Yoo <harry@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huang Ray <Ray.Huang@amd.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Namhyung kim <namhyung@kernel.org>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Steven Price <steven.price@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Thomas Zimemrmann <tzimmermann@suse.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Update the page_vma_mapped_walk structure to track whether the pgoff being
tracked is an anonymous pgoff or not and update the comments to reflect
this.
This is necessary in order to determine the correct VMA page offset in
vma_address_end() when pvmw->nr_pages > 1.
Also document that pvmw->pgoff is meaningless for pvmw->nr_pages == 1 and
for KSM.
Do not set this field where pgoff is not specified.
This is laying the groundwork for eventually using anonymous page offsets
as the index for all anonymous folios.
No functional change intended.
Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-10-c21581c0c3c8@kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Deucher <alexander.deucher@amd.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Chris Li <chrisl@kernel.org>
Cc: Christan König <christian.koenig@amd.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Gregory Price (Meta) <gourry@gourry.net>
Cc: Harry Yoo <harry@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huang Ray <Ray.Huang@amd.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Namhyung kim <namhyung@kernel.org>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Steven Price <steven.price@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Thomas Zimemrmann <tzimmermann@suse.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
We must correctly update VMA anonymous page offset state on all VMA
operations that would result in it changing, with special attention given
to remapping.
We cover most cases by simply updating vma_set_range() to do so (with a
new anonymous page offset parameter), but also notably must update the
merging and mapping logic to propagate this parameter correctly.
The remap logic remains the same - we may update the anonymous page offset
if the VMA is unfaulted, but now this applies to MAP_PRIVATE file-backed
mappings too, so we update the code to reflect this.
Note that we use __linear_anon_page_index() upon remap as the VMA may be
shared, in order that we update the field consistently regardless of VMA
type.
Similarly, pass through anon page offset to the merge logic, updating the
vma_merge_struct struct to propagate it, and also use
__linear_anon_page_index() to obtain the anonymous page index so it can be
safely used for both shared and MAP_PRIVATE file-backed mappings.
In copy_vma(), the anonymous page offset is updated regardless of whether
the mapping is a CoW mapping or not. This is both to keep the anonymous
page offset consistent even for non-CoW mappings (it is set so should at
least remain correct) and makes the logic cleaner.
A self-merge however remains permitted only for mappings which can have a
populated vma->anon_vma and do not require alignment on a separate file
offset - that is pure anonymous VMAs, so only set can_self_merge if
vma_is_anonymous().
Finally, we update insert_vm_struct() to correctly set the anonymous page
offset on insertion of a VMA.
We simply ensure state is correctly propagated here, so no functional
changes are intended.
Also update VMA userland tests to reflect this change.
Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-9-c21581c0c3c8@kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Deucher <alexander.deucher@amd.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Chris Li <chrisl@kernel.org>
Cc: Christan König <christian.koenig@amd.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Gregory Price (Meta) <gourry@gourry.net>
Cc: Harry Yoo <harry@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huang Ray <Ray.Huang@amd.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Namhyung kim <namhyung@kernel.org>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Steven Price <steven.price@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Thomas Zimemrmann <tzimmermann@suse.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Assert that a VMA can be moved backwards, forwards and between a preceding
VMA and its old self.
In the cases in which the VMA merges only with itself expect that to be
achieved by expanding its old self, so assert that these function
correctly.
However in the case of a merge between a preceding VMA and itself the
original VMA is removed, so assert that the preceding VMA replaces the one
passed in as vmap and the merge is as expected.
Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-8-c21581c0c3c8@kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Deucher <alexander.deucher@amd.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Chris Li <chrisl@kernel.org>
Cc: Christan König <christian.koenig@amd.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Gregory Price (Meta) <gourry@gourry.net>
Cc: Harry Yoo <harry@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huang Ray <Ray.Huang@amd.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Namhyung kim <namhyung@kernel.org>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Steven Price <steven.price@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Thomas Zimemrmann <tzimmermann@suse.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The existing logic is very confusing so improve things. Firstly rename
the confusing faulted_in_anon_vma variable to can_self_merge and update
this when the page offset is updated.
What is being checked for is a 'self-merge' - that is between the VMA
being remapped and its prior VMA (remember that this is copy_vma() - if a
non-MREMAP_DONTUNMAP remap the original VMA is only removed afterwards).
This can happen if the VMA is moved immediately adjacent to itself, either
before or after it:
|----------------|----------------|
| | |
v | v
|...............||---------------||...............|
| new || old || new |
|...............||---------------||---------------|
In these cases the old VMA is simply expanded to cover the new range.
It is also possible for the move to both self-merge and merge with a prior
VMA if it is placed between a preceding VMA and its old self:
|---------------|
| |
v |
|---------------||...............||---------------|
| prev || new || old |
|---------------||...............||---------------|
In this case, the old VMA is removed and 'prev' is expanded and replaces
it.
Since copy_vma_and_data() which calls copy_vma() intends to reference the
old VMA after the merge, it must have this pointer updated.
This kind of self-merge is not possible with a succeeding merge, as the
merge always prefers to expand the preceding VMA if possible.
copy_vma() accounts for this by explicitly checking to see if a self-merge
occurred and updating the vmap pointer if so. However it incorrect did so
even for a subsequent merge (this is simply a noop so it had no impact).
So change this to only check for the case which matters - a backwards
merge - and rearrange the parameters to make it clearer we're doing that -
i.e. check new_vma->vm_start < old_vma_start (having already renamed
vma_start to old_vma_start to make it clear this is the previous VMA).
Also update the existing wall-of-text comment to be a lot clearer.
While we're here, replace the VM_BUG_ON_VMA() with a VM_WARN_ON_ONCE_VMA()
and update the VMA userland tests accordingly.
No functional change intended.
Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-7-c21581c0c3c8@kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Deucher <alexander.deucher@amd.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Chris Li <chrisl@kernel.org>
Cc: Christan König <christian.koenig@amd.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Gregory Price (Meta) <gourry@gourry.net>
Cc: Harry Yoo <harry@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huang Ray <Ray.Huang@amd.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Namhyung kim <namhyung@kernel.org>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Steven Price <steven.price@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Thomas Zimemrmann <tzimmermann@suse.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
In cases where we know that the VMA is file-backed, use
vma_filebacked_address() rather than vma_address().
This lays the foundation for using the anonymous page offset via
vma_anon_address().
Also add an assert to ensure that the VMA whose address is required is not
anonymous.
No functional change intended.
Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-6-c21581c0c3c8@kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Tested-by: syzbot@syzkaller.appspotmail.com
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Deucher <alexander.deucher@amd.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Chris Li <chrisl@kernel.org>
Cc: Christan König <christian.koenig@amd.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Gregory Price (Meta) <gourry@gourry.net>
Cc: Harry Yoo <harry@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huang Ray <Ray.Huang@amd.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Namhyung kim <namhyung@kernel.org>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Steven Price <steven.price@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Thomas Zimemrmann <tzimmermann@suse.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
If the VMA is a CoW mapping page offset may differ from anon page offset,
indicating different positions in the relevant rmap trees.
Update print_bad_page_map() to reflect that - if the mapping is non-CoW or
the indexes match, then output only one index as before, otherwise output
both with (file) or (anon) suffixes to reflect which is which.
It's not possible to give only one index as there is no folio available to
perform folio_test_anon() upon (the page table entry is bad so this is
unavailable).
This is potentially useful debugging information and matches the existing
page offset provided.
Use the raw __linear_anon_page_index() function so as to always output
this value regardless of whether the mapping is file-backed or not and to
avoid asserts that shouldn't apply here.
Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-5-c21581c0c3c8@kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Gregory Price (Meta) <gourry@gourry.net>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Deucher <alexander.deucher@amd.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Chris Li <chrisl@kernel.org>
Cc: Christan König <christian.koenig@amd.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Harry Yoo <harry@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huang Ray <Ray.Huang@amd.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Namhyung kim <namhyung@kernel.org>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Steven Price <steven.price@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Thomas Zimemrmann <tzimmermann@suse.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Introduce __vma_address() which abstracts the VMA start page offset field
as pgoff_start, then update vma_address() to use it.
Then introduce vma_anon_address() which does the equivalent of
vma_address(), only using the anonymous page offset of the VMA rather than
the file-backed one.
Also add an assert to ensure that the function is not called for mappings
which are file-backed but not MAP_PRIVATE to ensure it is only used in the
correct places.
This will be necessary for determining the address of a folio's index
within a VMA when the folio belongs to a MAP_PRIVATE file-backed VMA but
has been CoW'd, and thus is anonymous, once the anonymous VMA page offset
field is used for the reverse mapping.
No callers are updated, so no functional change intended.
Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-4-c21581c0c3c8@kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Deucher <alexander.deucher@amd.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Chris Li <chrisl@kernel.org>
Cc: Christan König <christian.koenig@amd.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Gregory Price (Meta) <gourry@gourry.net>
Cc: Harry Yoo <harry@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huang Ray <Ray.Huang@amd.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Namhyung kim <namhyung@kernel.org>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Steven Price <steven.price@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Thomas Zimemrmann <tzimmermann@suse.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
This function provides the anonymous equivalent of linear_page_index(),
instead offsetting based on the anonymous page offset of the VMA.
It is valid only for anonymous or MAP_PRIVATE file-backed mappings, in
other words CoW mappings.
For pure anon VMAs, this will be equal to linear_page_index().
Assert that both of these invariants are true in linear_anon_page_index()
and implement the algorithm in __linear_anon_page_index().
Note that MAP_PRIVATE-/dev/zero mappings will satisfy vma_is_anonymous()
but not fulfill this invariant, so when asserting this we check
vma->vm_file to account for this.
We do not update callsites yet, so no functional change intended.
Also const-ify vma_is_anonymous() to make it compatible with the
const-ified linear_anon_page_index().
While we're here, update linear_page_index() to be more succinct.
VMA userland tests are also updated accordingly.
Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-3-c21581c0c3c8@kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Reviewed-by: Gregory Price (Meta) <gourry@gourry.net>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Deucher <alexander.deucher@amd.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Chris Li <chrisl@kernel.org>
Cc: Christan König <christian.koenig@amd.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Harry Yoo <harry@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huang Ray <Ray.Huang@amd.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Namhyung kim <namhyung@kernel.org>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Steven Price <steven.price@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Thomas Zimemrmann <tzimmermann@suse.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
All remaining callers of is_cow_mapping() are invoking it in the form of
is_cow_mapping(vma->vm_flags) or an indirected version of this.
Therefore, provide a helper - vma_is_cow_mapping() to directly test the
VMA.
Additionally provide a new helper vma_flags_is_cow_mapping() which
performs the check using the new vma_flags_t type, and share this logic
between vma_is_cow_mapping() and vma_desc_is_cow_mapping().
With these changes, no callers of is_cow_mapping() remain, so remove it.
Also update the userland VMA tests to reflect the change.
No functional change intended.
[akpm@linux-foundation.org: fix kerneldoc comment typo, per Lorenzo]
Link: https://lore.kernel.org/aob1goSSPH6sTN9y@gremlin
Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-2-c21581c0c3c8@kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Deucher <alexander.deucher@amd.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Chris Li <chrisl@kernel.org>
Cc: Christan König <christian.koenig@amd.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Gregory Price (Meta) <gourry@gourry.net>
Cc: Harry Yoo <harry@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huang Ray <Ray.Huang@amd.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Namhyung kim <namhyung@kernel.org>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Steven Price <steven.price@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Thomas Zimemrmann <tzimmermann@suse.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Patch series "mm/rmap: index MAP_PRIVATE file-backed folios by anonymous
pgoff", v5.
In memory management we've managed to manufacture a great deal of
confusion around the concept of anonymous memory. We have:
1. 'Pure anon' memory - anonymous VMAs whose folios are anonymous and
swap-backed (thus for reclaim purposes, treated as anonymous). These are
simple enough.
2. shmem - file-backed VMAs, file-backed folios (from rmap perspective) so
present in the page cache and mapped by an address_space object, but
whose folios are also swap-backed (thus treated as anonymous for reclaim
purposes).
3. MAP_PRIVATE-mapped /dev/zero - a strange beast whose VMAs have
vma->vm_file set, but which clears vma->vm_ops to satisfy
vma_is_anonymous(), resulting in VMAs that were mmap()'d referencing a
file, but are in every other sense anonymous, including the folios.
4. Other MAP_PRIVATE-file backed mappings - These possess file-backed VMAs
and have file-backed folios until CoW'd, at which point those CoW'd
folios are anonymous.
This series fixes issue 3.
In order for us to traverse VMAs using the reverse mapping, we require two
fields - folio->mapping and folio->index. The first tells the rmap code
where to look for VMAs, and the second tells it at which offset the folio
starts within the referenced object.
For anonymous folios, folio->mapping points at an anon_vma object. For
file-backed folios, it points at an address_space. And:
* For file-backed folios folio->index is simply the page offset of the start
of the folio within the file.
* For anonymous folios belonging to pure anon mappings, folio->index is
equal to the anonymous page offset of the folio.
* For anonymous folios belonging to file-backed mappings (i.e. CoW'd folios
of a MAP_PRIVATE file-backed mapping), folio->index is equal to the file
page offset.
This series establishes a new anonymous page offset property of VMAs to
allow us to map anonymous folios at their anonymous page offset,
consistent with pure anon.
The purpose of doing so is to lay the foundations for the scalable CoW
work. This is necessary because scalable CoW looks in the maple tree for
the VMA located at folio->index << PAGE_SHIFT, before falling back to
looking up tracked remaps if necessary.
The MAP_PRIVATE file-backed case means that folio indices will very often
conflict with one another and this remap tracking becomes substantially
more contended, and of course the fast path can never be used.
This also makes it possible, in future, to unshare anonymously mapped
folios with deep fork hierarchies on remap, eliminating the need for remap
tracking in the vast majority of cases.
Similar to page offset of pure anonymous VMAs, we update the anonymous
page offset of unfaulted file-backed VMAs on remap, but do not once CoW'd
(i.e. vma->anon_vma is non-NULL).
Overall, there is little impact on mergeability, which remains exactly the
same for pure anonymous and shared file-backed mappings, with the only
impact being on MAP_PRIVATE-mapped file-backed mappings, which must now
match on anonymous page offset as well as file page offset to be merged.
To fail to merge like this would require CoW'ing the mapping, then finding
another VMA with identical file and compatible page offset to remap next
to.
This is therefore very much an edge case that should have very little
impact (and which scalable CoW may very well address in any case).
This patch (of 16):
Establish fields in vm_area_struct to store the anonymous page offset of
VMAs.
Initially, the anonymous page offset of a VMA is vma->vm_start >>
PAGE_SHIFT.
When a VMA is remapped to new_address its anonymous page offset is either
updated to new_address >> PAGE_SHIFT if unfaulted or, if faulted, remains
equal to the anonymous page offset it had when first faulted.
Currently, anonymous folios belonging to CoW'd MAP_PRIVATE-mapped
file-backed VMAs are tracked by their file offsets. By adding anonymous
offset as a property of VMAs, we can now track them by their anonymous
page offset instead.
By tracking this, we provide the means by which to eliminate this
inconsistency, and more importantly lay the foundations for future work
for the scalable CoW anonymous rmap rework.
This patch simply adds the fields and some simple helpers. Subsequent
patches will update mm code to make use of these fields correctly.
The fields chosen are packed in the VMA such that, for 64-bit kernel
builds, no additional space is taken up.
The first field is present on cacheline 0 containing key VMA fields, and
the second on cacheline 3, which contains file-backed reverse mapping
fields.
Given the relative time spent accessing reverse mapping fields as well as
updating them, there shouldn't be any performance impact here from false
sharing.
Update the VMA userland tests to account for this change.
No callsites are updated yet, so no functional change intended.
Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-0-c21581c0c3c8@kernel.org
Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-1-c21581c0c3c8@kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Gregory Price (Meta) <gourry@gourry.net>
Reviewed-by: Xu Xin <xu.xin16@zte.com.cn>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Deucher <alexander.deucher@amd.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Chris Li <chrisl@kernel.org>
Cc: Christan König <christian.koenig@amd.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Harry Yoo <harry@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huang Ray <Ray.Huang@amd.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Namhyung kim <namhyung@kernel.org>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Steven Price <steven.price@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Thomas Zimemrmann <tzimmermann@suse.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Some mm Kconfig entries repeat dependencies that are already expressed by
their surrounding blocks or menus.
The zsmalloc allocator options menu already depends on ZSMALLOC, so the
outer if ZSMALLOC block does not add any extra constraint.
MEMORY_HOTREMOVE and MHP_MEMMAP_ON_MEMORY are both inside the if
MEMORY_HOTPLUG block, so their local depends on MEMORY_HOTPLUG entries are
redundant.
PTE_MARKER_UFFD_WP is the only entry under if USERFAULTFD. Move the
USERFAULTFD dependency into the symbol itself and combine it with the
architecture support dependency.
This keeps the same visibility and defaults while avoiding duplicate
dependency expressions.
Link: https://lore.kernel.org/20260712093326.8313-1-kaitao.cheng@linux.dev
Signed-off-by: Kaitao Cheng <chengkaitao@kylinos.cn>
Suggested-by: Julian Braha <julianbraha@gmail.com>
Reviewed-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Bad page map reporting currently stores page table entry values in an
unsigned long long and prints them with fixed 64-bit-oriented format
strings. This is inconsistent across call sites and does not work well
for architectures where page table entry values are not naturally
represented as 64-bit values, such as 32-bit or 128-bit entries.
Introduce a common helper to convert raw page table entry values into a
fixed-width hexadecimal string based on the actual entry size. Use it for
bad page map reporting and for dumping the page table walk in
__print_bad_page_map_pgtable().
Pass page table entry values to the reporting path as raw bytes together
with their size, instead of forcing them through an unsigned long long.
It keeps the printed output consistent and avoids truncation or misleading
formatting for non-64-bit page table entries.
Link: https://lore.kernel.org/20260709044334.1741263-1-anshuman.khandual@arm.com
Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
Co-developed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Andriy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
MHP_MEMMAP_ON_MEMORY is defined inside the MEMORY_HOTPLUG block, and
MEMORY_HOTPLUG already depends on SPARSEMEM_VMEMMAP. Keep the explicit
MEMORY_HOTPLUG dependency for local readability, but drop the redundant
SPARSEMEM_VMEMMAP dependency.
ZONE_DEVICE depends on MEMORY_HOTREMOVE, which depends on MEMORY_HOTPLUG.
MEMORY_HOTPLUG in turn depends on SPARSEMEM_VMEMMAP. Drop the direct
MEMORY_HOTPLUG and SPARSEMEM_VMEMMAP dependencies from ZONE_DEVICE.
This does not change the set of valid configurations.
Link: https://lore.kernel.org/20260707090331.52971-1-kaitao.cheng@linux.dev
Signed-off-by: Kaitao Cheng <chengkaitao@kylinos.cn>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Acked-by: Muchun Song <muchun.song@linux.dev>
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: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
<linux/maple_tree.h> consults the macro CONFIG_MAPLE_RCU_DISABLED to
determine whether to disable the mt_in_rcu() function (by making it always
return false). This macro is not reachable via Kconfig, despite its name,
and is not documented anywhere. Remove it to avoid polluting the CONFIG_*
namespace.
Discovered while searching for CONFIG_* symbols referenced in code but not
defined in any Kconfig file.
Link: https://lore.kernel.org/20260610220905.99860-1-enelsonmoore@gmail.com
Signed-off-by: Ethan Nelson-Moore <enelsonmoore@gmail.com>
Acked-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Liam Howlett <liam@infradead.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Cc: Andrew Ballance <andrewjballance@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
When a user invokes munmap(2) on a partial region allocated by mmap(), the
kernel may split the original region if necessary and shrink it to the
correct size. At the beginning of vmi_shrink_vma(), the unused part is
cleared; however, an assertion is triggered if the shrink occurs after
split_vma().
This commit fixes the issue by correctly configuring the pointer to the
iterator at the end of split_vma().
This bug was detected using the Linux Test Project (LTP) test linked
below, running on a nommu UML (User-Mode Linux) environment (via an
out-of-tree extension to UML).
Here is a minimal reproducible chunk of code for this issue:
void *addr;
size_t pagesize = getpagesize();
addr = mmap(NULL, pagesize * 4, PROT_READ | PROT_WRITE,
MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
munmap(addr + pagesize * 1, pagesize);
This is the console output with CONFIG_DEBUG_MAPLE_TREE=y.
nommu: WARN at __mas_set_range:791 (1)
MAS: tree=0000000091c23b08 enode=0000000065057663
(ma_active)
Store Type:
node_store
[9/9] index=70af8000 last=ffffffffffffffff
min=0 max=ffffffffffffffff sheaf=0000000000000000, request 0
depth=0, flags=0
maple_tree(0000000091c23b08) flags 307, height 1 root 0000000083394c06
0-ffffffffffffffff: node 0000000010c90bd6 depth 0 type 1 parent
0000000050e1ddf8 contents: 0000000000000000 707A
7FFF 00000000eb0ac2b5 707AFFFF 0000000000000000 7093FFFF
0000000045ead616 7095FFFF 0000000000000000 7096CFFF 000
00000681c7151 7096FFFF 0000000000000000 70AF3FFF 000000006c78b9e9
70AF4FFF 000000001914ab0b 70AF7FFF 00000000000
00000 FFFFFFFFFFFFFFFF 0000000000000000 0 0000000000000000 0
0000000000000000 0 0000000000000000 0 0000000000000
000 0 00000000bca8be4f
0-707a7fff: 0000000000000000
707a8000-707affff: 00000000eb0ac2b5
707b0000-7093ffff: 0000000000000000
70940000-7095ffff: 0000000045ead616
70960000-7096cfff: 0000000000000000
7096d000-7096ffff: 00000000681c7151
70970000-70af3fff: 0000000000000000
70af4000-70af4fff: 000000006c78b9e9
70af5000-70af7fff: 000000001914ab0b
70af8000-ffffffffffffffff: 0000000000000000
nommu: Pass: 796 Run:797
Link: https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/syscalls/mseal/mseal02.c
Link: https://lore.kernel.org/20260702012546.665383-1-thehajime@gmail.com
Signed-off-by: Hajime Tazaki <thehajime@gmail.com>
Cc: Jann Horn <jannh@google.com>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Neha reports that mapped shmem aren't considered for NUMA balancing,
noting convergence problems and bandwidth bottlenecking for cachelib based
workloads on tiered memory systems.
Looking at the code and going through the git history, this doesn't
actually seem intentional:
Commit fc3147245d19 ("mm: numa: Limit NUMA scanning to migrate-on-fault
VMAs") added a vma_policy_mof() gate to task_numa_work() so VMAs whose
policy lacks MPOL_F_MOF are skipped from NUMA balancing scans. The
motivation was a real usecase: Oracle was pinning shared segments with
mbind(MPOL_BIND) so trapping faults was both expensive and pointless.
The handling of NULL from vm_ops->get_policy, however, treated "user
explicitly opted out" the same as "user never specified anything." For
VMAs whose shared policy is absent - the common case for shmem - the scan
was disabled too.
This issue is old. It probably hurts less in conventional NUMA. But it's
very noticeable on tiered systems, where entire tmpfs workingsets can get
stuck on lower-bandwidth memory.
Fix this by having vma_policy_mof() use __get_vma_policy() directly, and
thereby handle the fallback to task policy (-> preferred_node_policy() has
MPOL_F_MOF per default). Every other consumer of vm_ops->get_policy
already handles it this way, the scan-eligibility check was the outlier.
This preserves Mel's intended fix: don't scan stuff the user explicitly
pinned. But allow default policy vmas to participate in balancing.
Link: https://lore.kernel.org/20260629163337.1264881-1-hannes@cmpxchg.org
Fixes: fc3147245d19 ("mm: numa: Limit NUMA scanning to migrate-on-fault VMAs")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Neha Gholkar <nehagholkar@gmail.com>
Tested-by: Neha Gholkar <nehagholkar@gmail.com>
Reviewed-by: Gregory Price <gourry@gourry.net>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Acked-by: Balbir Singh <balbirs@nvidia.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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already-upstream changes to memcontrol.c, needed by "memcg: move
mem_cgroup_swappiness and vm_swappiness to mm/swap.h".
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Pull smb client updates from Paulo Alcantara:
- clear sensitive data after use (stack and heap cryptographic
keys/hashes)
- file size and cache synchronization fixes (fscache cookie
serialization and truncation handling)
- protocol validation and buffer safety fixes (prevent OOB access and
loff_t underflow)
- metadata and POSIX attribute fixes (proper hard-link counts and
setuid/setgid stripping)
- DFS cache and unmount fixes (prevent target-hint UAF and unmount
hangs)
- general client improvements (fix read request leaks, stats loops,
handle servers that don't support O_TMPFILE)
* tag 'cifs-fixes-7.3-rc1' of https://git.manguebit.org/linux: (33 commits)
cifs: fix loff_t underflow in cifs_remap_file_range() when len == 0
smb: client: reject a tree connect response whose byte count is too small
cifs: call pagecache_isize_extended() in cifs_setsize() when extending
smb: client: fix copy-paste error in WSL EA length accounting for $LXDEV
smb: client: remove redundant NULL check before kfree()
smb: client: restore the data_offset bound in is_valid_oplock_break()
cifs: clear tcon after cifsFileInfo_put() in cifs_file_set_size()
smb: client: Avoid leaking sensitive data to the heap in connect.c
smb: client: Clear sensitive stack data in smb1encrypt.c
smb: client: Clear sensitive stack data in cifsencrypt.c
smb: client: Clear sensitive stack and heap data in smb2ops.c
smb: client: Clear sensitive stack data in smb2transport.c
Revert "cifs: remove all cifs files before kill super"
smb: client: fix use-before-check of ReparseDataLength in reparse_buf_ptr()
smb: client: fix ALIGN() overflow in symlink_data() error context loop
smb: client: simplify __build_path_from_dentry_optional_prefix()
smb: client: fix UAF and buffer leak in cifs_check_trans2() for malformed secondary T2
smb: client: fix OOB read/write from unvalidated DataOffset in coalesce_t2()
smb/client: decode reparse metadata using its payload type
smb/client: preserve open info type across compound queries
...
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The removal of the architecture-specific asm/timex.h was meant to fall back to
asm-generic/timex.h. However on UML, the host architecture headers are earlier
on the include path and therefore asm/timex.h from the host architecture is
used.
On x86 that header in turn requires the generation of cpufeaturemasks.h, which
is not set up for UML and the build fails.
In file included from ../arch/x86/include/asm/tsc.h:9,
from ../arch/x86/include/asm/timex.h:6,
from ../include/linux/timex.h:67,
from ../include/linux/time32.h:13,
from ../include/linux/time.h:60,
from ../include/linux/jiffies.h:10,
from ../include/linux/ktime.h:25,
from ../include/linux/timer.h:6,
from ../include/linux/uprobes.h:18,
from ../include/linux/mm_types.h:16,
from ../include/linux/mmzone.h:22,
from ../include/linux/gfp.h:7,
from ../include/linux/slab.h:17,
from ../include/linux/crypto.h:18,
from ../arch/um/kernel/asm-offsets.c:6:
arch/x86/include/asm/tsc.h: In function ‘get_cycles’:
arch/um/include/asm/cpufeature.h:52:39: error: implicit declaration of function ‘DISABLED_MASK_BIT_SET’ [-Wimplicit-function-declaration]
52 | (__builtin_constant_p(bit) && DISABLED_MASK_BIT_SET(bit) ? 0 : _static_cpu_has(bit))
| ^~~~~~~~~~~~~~~~~~~~~
arch/x86/include/asm/tsc.h:79:14: note: in expansion of macro ‘cpu_feature_enabled’
79 | if (!cpu_feature_enabled(X86_FEATURE_TSC))
| ^~~~~~~~~~~~~~~~~~~
arch/um/include/asm/cpufeature.h:115:17: error: implicit declaration of function ‘_static_cpu_has’ [-Wimplicit-function-declaration]
115 | _static_cpu_has(bit) \
| ^~~~~~~~~~~~~~~
...
The x86-specific timex.h also doesn't make sense on UML in general.
Reintroduce the UML-specific asm/timex.h and add a comment to document
its necessity.
[ bp: Improve that comment to actually state why stuff is there. ]
Fixes: 3ed403bbc967 ("treewide: Remove CLOCK_TICK_RATE")
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: David Gow <david@davidgow.net>
Link: https://patch.msgid.link/20260819-uml-timex-fix-v1-1-f690b514fc9f@linutronix.de
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Bits 15:14 of NPU_SET_{IFM,OFM}_PRECISION select the activation storage
mode on U85 only. On U65 the same field holds the rounding mode, and the
command stream parser has read it as a storage mode since the driver was
added.
That went unnoticed while unknown values fell through the switch, but
now that they are rejected, every U65 command stream that asks for
natural rounding (2) fails CMDSTREAM_BO_CREATE with -EINVAL. Mesa emits
it for average pooling, concatenation, split, unpack, strided slice, LUT
and argmax, which is 72 failures of the Teflon test suite on an i.MX93.
Truncating rounding (1) is misread as well: it picks the two-tile
address path and computes a bogus feature map size from tile bases the
command stream never set.
Read the field as a storage mode only on the hardware where it is one.
Fixes: 5a5e9c0228e6 ("accel: Add Arm Ethos-U NPU driver")
Fixes: 6b7e0066294d ("accel: ethosu: Handle U85 internal chaining buffer")
Assisted-by: Claude:claude-opus-5
Signed-off-by: Tomeu Vizoso <tomeu@tomeuvizoso.net>
Link: https://patch.msgid.link/20260824152612.751007-1-tomeu@tomeuvizoso.net
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
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devm_platform_ioremap_resource() returns an error pointer when the register
resource cannot be mapped. ethosu_probe() stores it and continues until
initialization dereferences it through MMIO accessors.
Return the mapping error before initializing the device.
Fixes: 5a5e9c0228e6 ("accel: Add Arm Ethos-U NPU driver")
Cc: stable@vger.kernel.org
Signed-off-by: GuoHan Zhao <zhaoguohan@kylinos.cn>
Link: https://patch.msgid.link/20260716065219.931088-1-zhaoguohan@kylinos.cn
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
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eventfs_create_dir() allocates the eventfs_inode and initializes it with
init_ei(). But this does not initialize the eventfs_inode list_heads. If
the eventfs_create_dir() fails due to memory pressure, it will call
free_ei() before it initialized the lists, and that checks to make sure
the eventfs_inode has no children. But because the list wasn't
initialized, it will give a false warning.
Fix it by moving the list initialization into init_ei().
Cc: stable@vger.kernel.org
Fixes: 5790b1fb3d67 ("eventfs: Remove eventfs_file and just use eventfs_inode")
Reported-by: syzbot+3ef80b4ed02226d04a06@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=3ef80b4ed02226d04a06
Link: https://patch.msgid.link/20260824144653.54044-1-kartikey406@gmail.com
Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
[ Rewrote change log ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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With len == 0 (clone to EOF), the effective length is computed as:
len = src_inode->i_size - off;
If off > i_size, this is a negative loff_t, corrupting the ByteCount
in the FSCTL_DUPLICATE_EXTENTS_TO_FILE request and inverting the range
in filemap_write_and_wait_range(). The existing off >= i_size check
fires only after the ioctl has already been sent.
Snapshot i_size_read() once for both the bounds check and the length
calculation, eliminating the TOCTOU and 32-bit torn-read risk. Reject
off > src_size with -EINVAL. Treat off == src_size as a no-op,
consistent with __generic_remap_file_range_prep().
Fixes: 04b38d601239 ("vfs: pull btrfs clone API to vfs layer")
Cc: stable@vger.kernel.org
Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Reviewed-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
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CIFSTCon() bounds its strnlen() over the byte area with the server's
ByteCount minus two, which for ByteCount 0 or 1 goes negative as an int
and converts to a huge size_t. The later subtraction wraps the __u16
bytes_left, and that is what bounds cifs_strndup_from_utf16(): a bound of
up to 65535 against a ~16 KB cifs_req_poolp object runs off the end of the
slab object, and the bytes reach userspace through tcon->nativeFileSystem
in /proc/fs/cifs/DebugData.
Reject a byte area too small for what the parser consumes. Two bytes is
the least it can consume, and no conformant response carries fewer. The
new trace point is the 129th smb_eio_trace entry, which __mode(byte)
cannot represent, so the attribute goes with it.
Fixes: cc20c031bb06 ("cifs: convert CIFSTCon to use new unicode helper functions")
Cc: stable@vger.kernel.org
Signed-off-by: Bryam Vargas <hexlabsecurity@proton.me>
Reviewed-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
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cifs_setsize() calls truncate_pagecache() but skips
pagecache_isize_extended() on extension. truncate_setsize() shows
the correct pattern:
i_size_write(inode, newsize);
if (newsize > oldsize)
pagecache_isize_extended(inode, oldsize, newsize);
truncate_pagecache(inode, newsize);
pagecache_isize_extended() zeroes the tail of the page straddling old
EOF. Without it, dirty bytes in that region can be written back to
the server, exposing stale data in the newly extended range.
Cc: stable@vger.kernel.org
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
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The LXDEV block in cifs_query_path_info() uses SMB2_WSL_XATTR_MODE_SIZE
(4) instead of SMB2_WSL_XATTR_DEV_SIZE (8), undercounting eas_len by 4
bytes per $LXDEV EA.
eas_len is used only as a zero/non-zero presence flag so there is no
current functional impact, but the value is incorrect and misleading.
Fixes: 97db41604555 ("smb: client: parse uid, gid, mode and dev from WSL reparse points")
Cc: stable@vger.kernel.org
Cc: Paulo Alcantara <pc@manguebit.org>
Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
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kfree() safely handles NULL pointers, so the explicit NULL check
before calling kfree() is unnecessary.
This issue was reported by ifnullfree.cocci.
Signed-off-by: Mohammad Shahid <mdshahid03@gmail.com>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
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Commit 83bfbd0bb902 ("cifs: Remove the RFC1002 header from smb_hdr")
changed the quantity this bound is measured against. It used to be
srv->total_read minus the 4-byte RFC1002 preamble that total_read then
included, so it was the SMB message length. The same commit stopped
counting the preamble, and the mechanical substitution to
srv->total_read - srv->pdu_size left an expression that is identically
zero: standard_receive3() reads MID_HEADER_SIZE() bytes and then exactly
pdu_length - MID_HEADER_SIZE() more, adding both to total_read.
len is therefore 0, the subtraction below it wraps, and no __u32
DataOffset can exceed the result, so the check from commit 097f5863b1a0
("cifs: read overflow in is_valid_oplock_break()") no longer rejects
anything. Use total_read, which is now the message length on its own.
Fixes: 83bfbd0bb902 ("cifs: Remove the RFC1002 header from smb_hdr")
Cc: stable@kernel.org
Signed-off-by: Bryam Vargas <hexlabsecurity@proton.me>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
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When the else branch of cifs_file_set_size() finds a writable file handle
via find_writable_file(), it borrows tcon and server from the handle's
tlink, attempts the handle-based set_file_size() RPC, and then releases
the handle with cifsFileInfo_put().
If set_file_size() fails, execution falls through to the path-based
fallback, which reuses the borrowed tcon and server under the
"if (tcon == NULL)" guard. Since tcon is not NULL at that point, the
guard is skipped. If cifsFileInfo_put() dropped the last reference on a
tlink that was already removed from the tlink tree (TCON_LINK_IN_TREE
cleared, as happens during reconnection or session teardown),
cifs_put_tlink() will have freed tcon; the subsequent set_path_size()
call is then a use-after-free.
Setting tcon = NULL after cifsFileInfo_put() causes the existing guard
to take the cifs_sb_tlink() path, which acquires a fresh reference for
the path-based operation or fails cleanly if the session is gone.
Fixes: 110fee6b9bb5 ("smb: client: fix missing timestamp updates with O_TRUNC")
Cc: stable@vger.kernel.org
Cc: Paulo Alcantara <pc@manguebit.com>
Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
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TCP_Server_Info contains a preauth_sha_hash[] and a cryptkey[] array
that might contain sensitive data. Thus free its memory with
kfree_sensitive() to avoid that we are leaking this information to
the heap.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
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Make sure to not leak signature data via the stack, clear it
with memzero_explicit() before leaving the function.
To avoid that we have to introduce "goto"-cleanup here, we re-arrange
the code a little bit (and drop the commented cifs_dump_mem debug
code that looks like a leftover from very early days).
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
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Make sure to not leak hash data via the stack, clear it
with memzero_explicit() before leaving the function.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
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Make sure to not leak key-related data via the heap or the stack
by using kfree_sensitive() or memzero_explicit() here.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
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Sensitive data like keys that are stored in stack-local arrays could
be leaked via the stack to the calling functions. There is no known
vulnerability for this right now, but it's good security style to
explicitly zeroize this sensitive material as soon as possible to
avoid that it could be exploited together with other bugs later.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
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This reverts commit 6d9a4aaaa8b2612b5ef9d581e2f286a458b71ee1.
First, directly flushing fileinfo_put_wq in that commit cannot guarantee
that all in-flight I/O has run its cleanup_work on system_dfl_wq and
subsequently called queue_work(fileinfo_put_wq, ...). Flushing only the
latter workqueue may therefore miss puts that have not yet been queued, so
the fix is not reliable in the first place. Moreover, this fix flushes
inside cifs_umount(), which means the busy-dentry warning can still be
triggered when umount_check() is called inside kill_anon_super(), because
kill_anon_super() is executed before cifs_umount().
Second, commit 75f5c412fa86 ("smb: client: fix busy dentry warning on
unmount after DIO") already drains both serverclose_wq and fileinfo_put_wq
in cifs_kill_sb(), before kill_anon_super(). By adding a per-superblock
outstanding-rreq counter, it guarantees that all cleanup_work for this sb
have run, and thus all relevant cfile puts are queued on fileinfo_put_wq
or serverclose_wq.
Third, no path between those drains and cifs_umount() can queue new work
onto either workqueue. In the "cifs_sb->root == NULL" path there are no
file-related workers either, so that case is safe as well.
Therefore the busy-dentry and null-ptr-deref problems cannot arise, and
the flush added by commit 6d9a4aaaa8b2 ("cifs: remove all cifs files before
kill super") is redundant and can be removed.
Signed-off-by: Zizhi Wo <wozizhi@huawei.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
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reparse_buf_ptr() reads buf->ReparseDataLength before checking that
count covers the full fixed header:
buf = (struct reparse_data_buffer *)((u8 *)io + off);
len = sizeof(*buf); /* 8 bytes */
rdlen = le16_to_cpu(buf->ReparseDataLength); /* offset 4, 2 bytes */
if (count < len || count < rdlen + len) /* check comes after */
struct reparse_data_buffer has ReparseDataLength at offset 4. If a
server returns OutputCount < 6, the read at offset 4-5 reaches past
the end of the received data. The off+count bounds against iov_len
were already validated, but that does not protect against count being
smaller than sizeof(*buf).
Split the check: verify count >= sizeof(*buf) before reading
ReparseDataLength, then verify count covers the data region.
Fixes: a158bb66b137 ("smb: client: optimise reparse point querying")
Cc: stable@vger.kernel.org
Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
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The check added by commit 7d9a7f1f96cd ("smb/client: fix possible
infinite loop and oob read in symlink_data()") compared the post-ALIGN
length against the remaining buffer, but ALIGN() itself can overflow:
for ErrorDataLength near UINT32_MAX (e.g. 0xFFFFFFF9), ALIGN(x, 8)
wraps to 0, so the subsequent bounds check passes, and the loop
advances by zero bytes leaving 'p' pointing into stale data.
Fix by checking the raw ErrorDataLength against the remaining space
before applying ALIGN(), then checking again after. Since raw_len is
bounded by the buffer, raw_len + 7 cannot overflow, so the second check
is an exact post-alignment bounds guard.
Fixes: 76894f3e2f71 ("cifs: improve symlink handling for smb2+")
Cc: stable@vger.kernel.org
Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
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