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This commit fixes two kinds of races, they may have different results:
Barry reported a BUG_ON in commit c50f8e6053b0, we may see the same
BUG_ON if the filemap lookup returned NULL and folio is added to swap
cache after that.
If another kind of race is triggered (folio changed after lookup) we
may see RSS counter is corrupted:
[ 406.893936] BUG: Bad rss-counter state mm:ffff0000c5a9ddc0
type:MM_ANONPAGES val:-1
[ 406.894071] BUG: Bad rss-counter state mm:ffff0000c5a9ddc0
type:MM_SHMEMPAGES val:1
Because the folio is being accounted to the wrong VMA.
I'm not sure if there will be any data corruption though, seems no.
The issues above are critical already.
On seeing a swap entry PTE, userfaultfd_move does a lockless swap cache
lookup, and tries to move the found folio to the faulting vma. Currently,
it relies on checking the PTE value to ensure that the moved folio still
belongs to the src swap entry and that no new folio has been added to the
swap cache, which turns out to be unreliable.
While working and reviewing the swap table series with Barry, following
existing races are observed and reproduced [1]:
In the example below, move_pages_pte is moving src_pte to dst_pte, where
src_pte is a swap entry PTE holding swap entry S1, and S1 is not in the
swap cache:
CPU1 CPU2
userfaultfd_move
move_pages_pte()
entry = pte_to_swp_entry(orig_src_pte);
// Here it got entry = S1
... < interrupted> ...
<swapin src_pte, alloc and use folio A>
// folio A is a new allocated folio
// and get installed into src_pte
<frees swap entry S1>
// src_pte now points to folio A, S1
// has swap count == 0, it can be freed
// by folio_swap_swap or swap
// allocator's reclaim.
<try to swap out another folio B>
// folio B is a folio in another VMA.
<put folio B to swap cache using S1 >
// S1 is freed, folio B can use it
// for swap out with no problem.
...
folio = filemap_get_folio(S1)
// Got folio B here !!!
... < interrupted again> ...
<swapin folio B and free S1>
// Now S1 is free to be used again.
<swapout src_pte & folio A using S1>
// Now src_pte is a swap entry PTE
// holding S1 again.
folio_trylock(folio)
move_swap_pte
double_pt_lock
is_pte_pages_stable
// Check passed because src_pte == S1
folio_move_anon_rmap(...)
// Moved invalid folio B here !!!
The race window is very short and requires multiple collisions of multiple
rare events, so it's very unlikely to happen, but with a deliberately
constructed reproducer and increased time window, it can be reproduced
easily.
This can be fixed by checking if the folio returned by filemap is the
valid swap cache folio after acquiring the folio lock.
Another similar race is possible: filemap_get_folio may return NULL, but
folio (A) could be swapped in and then swapped out again using the same
swap entry after the lookup. In such a case, folio (A) may remain in the
swap cache, so it must be moved too:
CPU1 CPU2
userfaultfd_move
move_pages_pte()
entry = pte_to_swp_entry(orig_src_pte);
// Here it got entry = S1, and S1 is not in swap cache
folio = filemap_get_folio(S1)
// Got NULL
... < interrupted again> ...
<swapin folio A and free S1>
<swapout folio A re-using S1>
move_swap_pte
double_pt_lock
is_pte_pages_stable
// Check passed because src_pte == S1
folio_move_anon_rmap(...)
// folio A is ignored !!!
Fix this by checking the swap cache again after acquiring the src_pte
lock. And to avoid the filemap overhead, we check swap_map directly [2].
The SWP_SYNCHRONOUS_IO path does make the problem more complex, but so far
we don't need to worry about that, since folios can only be exposed to the
swap cache in the swap out path, and this is covered in this patch by
checking the swap cache again after acquiring the src_pte lock.
Testing with a simple C program that allocates and moves several GB of
memory did not show any observable performance change.
Link: https://lkml.kernel.org/r/20250604151038.21968-1-ryncsn@gmail.com
Fixes: adef440691ba ("userfaultfd: UFFDIO_MOVE uABI")
Signed-off-by: Kairui Song <kasong@tencent.com>
Closes: https://lore.kernel.org/linux-mm/CAMgjq7B1K=6OOrK2OUZ0-tqCzi+EJt+2_K97TPGoSt=9+JwP7Q@mail.gmail.com/ [1]
Link: https://lore.kernel.org/all/CAGsJ_4yJhJBo16XhiC-nUzSheyX-V3-nFE+tAi=8Y560K8eT=A@mail.gmail.com/ [2]
Reviewed-by: Lokesh Gidra <lokeshgidra@google.com>
Acked-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Barry Song <baohua@kernel.org>
Reviewed-by: Chris Li <chrisl@kernel.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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After commit 1aaf8c122918 ("mm: gup: fix infinite loop within
__get_longterm_locked") we are able to longterm pin folios that are not
supposed to get longterm pinned, simply because they temporarily have the
LRU flag cleared (esp. temporarily isolated).
For example, two __get_longterm_locked() callers can race, or
__get_longterm_locked() can race with anything else that temporarily
isolates folios.
The introducing commit mentions the use case of a driver that uses
vm_ops->fault to insert pages allocated through cma_alloc() into the page
tables, assuming they can later get longterm pinned. These pages/ folios
would never have the LRU flag set and consequently cannot get isolated.
There is no known in-tree user making use of that so far, fortunately.
To handle that in the future -- and avoid retrying forever to
isolate/migrate them -- we will need a different mechanism for the CMA
area *owner* to indicate that it actually already allocated the page and
is fine with longterm pinning it. The LRU flag is not suitable for that.
Probably we can lookup the relevant CMA area and query the bitmap; we only
have have to care about some races, probably. If already allocated, we
could just allow longterm pinning)
Anyhow, let's fix the "must not be longterm pinned" problem first by
reverting the original commit.
Link: https://lkml.kernel.org/r/20250611131314.594529-1-david@redhat.com
Fixes: 1aaf8c122918 ("mm: gup: fix infinite loop within __get_longterm_locked")
Signed-off-by: David Hildenbrand <david@redhat.com>
Closes: https://lore.kernel.org/all/20250522092755.GA3277597@tiffany/
Reported-by: Hyesoo Yu <hyesoo.yu@samsung.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Peter Xu <peterx@redhat.com>
Cc: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
Cc: Aijun Sun <aijun.sun@unisoc.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The mm selftests are timing out with the current 180-second limit.
Testing shows that run_vmtests.sh takes approximately 11 minutes
(664 seconds) to complete.
Increase the timeout to 900 seconds (15 minutes) to provide sufficient
buffer for the tests to complete successfully.
Link: https://lkml.kernel.org/r/20250609120606.73145-2-shivankg@amd.com
Signed-off-by: Shivank Garg <shivankg@amd.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Following softlockup can be easily reproduced on my test machine with:
echo always > /sys/kernel/mm/transparent_hugepage/hugepages-64kB/enabled
swapon /dev/zram0 # zram0 is a 48G swap device
mkdir -p /sys/fs/cgroup/memory/test
echo 1G > /sys/fs/cgroup/test/memory.max
echo $BASHPID > /sys/fs/cgroup/test/cgroup.procs
while true; do
dd if=/dev/zero of=/tmp/test.img bs=1M count=5120
cat /tmp/test.img > /dev/null
rm /tmp/test.img
done
Then after a while:
watchdog: BUG: soft lockup - CPU#0 stuck for 763s! [cat:5787]
Modules linked in: zram virtiofs
CPU: 0 UID: 0 PID: 5787 Comm: cat Kdump: loaded Tainted: G L 6.15.0.orig-gf3021d9246bc-dirty #118 PREEMPT(voluntary)·
Tainted: [L]=SOFTLOCKUP
Hardware name: Red Hat KVM/RHEL-AV, BIOS 0.0.0 02/06/2015
RIP: 0010:mpol_shared_policy_lookup+0xd/0x70
Code: e9 b8 b4 ff ff 31 c0 c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 0f 1f 44 00 00 41 54 55 53 <48> 8b 1f 48 85 db 74 41 4c 8d 67 08 48 89 fb 48 89 f5 4c 89 e7 e8
RSP: 0018:ffffc90002b1fc28 EFLAGS: 00000202
RAX: 00000000001c20ca RBX: 0000000000724e1e RCX: 0000000000000001
RDX: ffff888118e214c8 RSI: 0000000000057d42 RDI: ffff888118e21518
RBP: 000000000002bec8 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000bf4 R11: 0000000000000000 R12: 0000000000000001
R13: 00000000001c20ca R14: 00000000001c20ca R15: 0000000000000000
FS: 00007f03f995c740(0000) GS:ffff88a07ad9a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f03f98f1000 CR3: 0000000144626004 CR4: 0000000000770eb0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
<TASK>
shmem_alloc_folio+0x31/0xc0
shmem_swapin_folio+0x309/0xcf0
? filemap_get_entry+0x117/0x1e0
? xas_load+0xd/0xb0
? filemap_get_entry+0x101/0x1e0
shmem_get_folio_gfp+0x2ed/0x5b0
shmem_file_read_iter+0x7f/0x2e0
vfs_read+0x252/0x330
ksys_read+0x68/0xf0
do_syscall_64+0x4c/0x1c0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f03f9a46991
Code: 00 48 8b 15 81 14 10 00 f7 d8 64 89 02 b8 ff ff ff ff eb bd e8 20 ad 01 00 f3 0f 1e fa 80 3d 35 97 10 00 00 74 13 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 4f c3 66 0f 1f 44 00 00 55 48 89 e5 48 83 ec
RSP: 002b:00007fff3c52bd28 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000040000 RCX: 00007f03f9a46991
RDX: 0000000000040000 RSI: 00007f03f98ba000 RDI: 0000000000000003
RBP: 00007fff3c52bd50 R08: 0000000000000000 R09: 00007f03f9b9a380
R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000040000
R13: 00007f03f98ba000 R14: 0000000000000003 R15: 0000000000000000
</TASK>
The reason is simple, readahead brought some order 0 folio in swap cache,
and the swapin mTHP folio being allocated is in conflict with it, so
swapcache_prepare fails and causes shmem_swap_alloc_folio to return
-EEXIST, and shmem simply retries again and again causing this loop.
Fix it by applying a similar fix for anon mTHP swapin.
The performance change is very slight, time of swapin 10g zero folios
with shmem (test for 12 times):
Before: 2.47s
After: 2.48s
[kasong@tencent.com: add comment]
Link: https://lkml.kernel.org/r/20250610181645.45922-1-ryncsn@gmail.com
Link: https://lkml.kernel.org/r/20250610181645.45922-1-ryncsn@gmail.com
Link: https://lkml.kernel.org/r/20250609171751.36305-1-ryncsn@gmail.com
Fixes: 1dd44c0af4fa ("mm: shmem: skip swapcache for swapin of synchronous swap device")
Signed-off-by: Kairui Song <kasong@tencent.com>
Reviewed-by: Barry Song <baohua@kernel.org>
Acked-by: Nhat Pham <nphamcs@gmail.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Usama Arif <usamaarif642@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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As we always iterate through the entire die_map when expanding
type strings, recursively processing referenced types in
type_expand_child() is not actually necessary. Furthermore,
the type_string kABI rule added in commit c9083467f7b9
("gendwarfksyms: Add a kABI rule to override type strings") can
fail to override type strings for structures due to a missing
kabi_get_type_string() check in this function.
Fix the issue by dropping the unnecessary recursion and moving
the override check to type_expand(). Note that symbol versions
are otherwise unchanged with this patch.
Fixes: c9083467f7b9 ("gendwarfksyms: Add a kABI rule to override type strings")
Reported-by: Giuliano Procida <gprocida@google.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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This hides excessive warnings, as nobody builds with W=2.
Fixes: a934a57a42f6 ("scripts/misc-check: check missing #include <linux/export.h> when W=1")
Fixes: 7d95680d64ac ("scripts/misc-check: check unnecessary #include <linux/export.h> when W=1")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
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In preparation for needing to shift NVMe passthrough to always use
task_work for polled IO completions, ensure that those are suitably
run at exit time. See commit:
9ce6c9875f3e ("nvme: always punt polled uring_cmd end_io work to task_work")
for details on why that is necessary.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Currently NVMe uring_cmd completions will complete locally, if they are
polled. This is done because those completions are always invoked from
task context. And while that is true, there's no guarantee that it's
invoked under the right ring context, or even task. If someone does
NVMe passthrough via multiple threads and with a limited number of
poll queues, then ringA may find completions from ringB. For that case,
completing the request may not be sound.
Always just punt the passthrough completions via task_work, which will
redirect the completion, if needed.
Cc: stable@vger.kernel.org
Fixes: 585079b6e425 ("nvme: wire up async polling for io passthrough commands")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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If an exiting non-autoreaping task has already passed exit_notify() and
calls handle_posix_cpu_timers() from IRQ, it can be reaped by its parent
or debugger right after unlock_task_sighand().
If a concurrent posix_cpu_timer_del() runs at that moment, it won't be
able to detect timer->it.cpu.firing != 0: cpu_timer_task_rcu() and/or
lock_task_sighand() will fail.
Add the tsk->exit_state check into run_posix_cpu_timers() to fix this.
This fix is not needed if CONFIG_POSIX_CPU_TIMERS_TASK_WORK=y, because
exit_task_work() is called before exit_notify(). But the check still
makes sense, task_work_add(&tsk->posix_cputimers_work.work) will fail
anyway in this case.
Cc: stable@vger.kernel.org
Reported-by: Benoît Sevens <bsevens@google.com>
Fixes: 0bdd2ed4138e ("sched: run_posix_cpu_timers: Don't check ->exit_state, use lock_task_sighand()")
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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If peeking a bunch of buffers, normally io_ring_buffers_peek() will
truncate the end buffer. This isn't optimal as presumably more data will
be arriving later, and hence it's better to stop with the last full
buffer rather than truncate the end buffer.
Cc: stable@vger.kernel.org
Fixes: 35c8711c8fc4 ("io_uring/kbuf: add helpers for getting/peeking multiple buffers")
Reported-by: Christian Mazakas <christian.mazakas@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Stephen Rothwell reports htmldocs warning on ublk docs:
Documentation/block/ublk.rst:414: ERROR: Unexpected indentation. [docutils]
Fix the warning by separating sublists of auto buffer registration
fallback behavior from their appropriate parent list item.
Fixes: ff20c516485e ("ublk: document auto buffer registration(UBLK_F_AUTO_BUF_REG)")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/linux-next/20250612132638.193de386@canb.auug.org.au/
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Link: https://lore.kernel.org/r/20250613023857.15971-1-bagasdotme@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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This driver uses a mixture of ways to get the size of a PTE,
tegra_smmu_set_pde() did it as sizeof(*pd) which became wrong when pd
switched to a struct tegra_pd.
Switch pd back to a u32* in tegra_smmu_set_pde() so the sizeof(*pd)
returns 4.
Fixes: 50568f87d1e2 ("iommu/terga: Do not use struct page as the handle for as->pd memory")
Reported-by: Diogo Ivo <diogo.ivo@tecnico.ulisboa.pt>
Closes: https://lore.kernel.org/all/62e7f7fe-6200-4e4f-ad42-d58ad272baa6@tecnico.ulisboa.pt/
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Tested-by: Diogo Ivo <diogo.ivo@tecnico.ulisboa.pt>
Link: https://lore.kernel.org/r/0-v1-da7b8b3d57eb+ce-iommu_terga_sizeof_jgg@nvidia.com
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
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Similarly to 26064d3e2b4d ("block: fix adding folio to bio"), if
we attempt to add a folio that is larger than 4GB, we'll silently
truncate the offset and len. Widen the parameters to size_t, assert
that the length is less than 4GB and set the first page that contains
the interesting data rather than the first page of the folio.
Fixes: 26db5ee15851 (block: add a bvec_set_folio helper)
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20250612144255.2850278-1-willy@infradead.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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It is possible for physically contiguous folios to have discontiguous
struct pages if SPARSEMEM is enabled and SPARSEMEM_VMEMMAP is not.
This is correctly handled by folio_page_idx(), so remove this open-coded
implementation.
Fixes: 640d1930bef4 (block: Add bio_for_each_folio_all())
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20250612144126.2849931-1-willy@infradead.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Removes MSI-X from the interrupt request path, as the DMA engine used by
the SPI controller does not support MSI-X interrupts.
Signed-off-by: Thangaraj Samynathan <thangaraj.s@microchip.com>
Link: https://patch.msgid.link/20250612023059.71726-1-thangaraj.s@microchip.com
Signed-off-by: Mark Brown <broonie@kernel.org>
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Nested file systems, that is those which invoke call_mmap() within their
own f_op->mmap() handlers, may encounter underlying file systems which
provide the f_op->mmap_prepare() hook introduced by commit c84bf6dd2b83
("mm: introduce new .mmap_prepare() file callback").
We have a chicken-and-egg scenario here - until all file systems are
converted to using .mmap_prepare(), we cannot convert these nested
handlers, as we can't call f_op->mmap from an .mmap_prepare() hook.
So we have to do it the other way round - invoke the .mmap_prepare() hook
from an .mmap() one.
in order to do so, we need to convert VMA state into a struct vm_area_desc
descriptor, invoking the underlying file system's f_op->mmap_prepare()
callback passing a pointer to this, and then setting VMA state accordingly
and safely.
This patch achieves this via the compat_vma_mmap_prepare() function, which
we invoke from call_mmap() if f_op->mmap_prepare() is specified in the
passed in file pointer.
We place the fundamental logic into mm/vma.h where VMA manipulation
belongs. We also update the VMA userland tests to accommodate the
changes.
The compat_vma_mmap_prepare() function and its associated machinery is
temporary, and will be removed once the conversion of file systems is
complete.
We carefully place this code so it can be used with CONFIG_MMU and also
with cutting edge nommu silicon.
[akpm@linux-foundation.org: export compat_vma_mmap_prepare tp fix build]
[lorenzo.stoakes@oracle.com: remove unused declarations]
Link: https://lkml.kernel.org/r/ac3ae324-4c65-432a-8c6d-2af988b18ac8@lucifer.local
Link: https://lkml.kernel.org/r/20250609165749.344976-1-lorenzo.stoakes@oracle.com
Fixes: c84bf6dd2b83 ("mm: introduce new .mmap_prepare() file callback").
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reported-by: Jann Horn <jannh@google.com>
Closes: https://lore.kernel.org/linux-mm/CAG48ez04yOEVx1ekzOChARDDBZzAKwet8PEoPM4Ln3_rk91AzQ@mail.gmail.com/
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Currently, cached directory contents were not reused across subsequent
'ls' operations because the cache validity check relied on comparing
the ctx pointer, which changes with each readdir invocation. As a
result, the cached dir entries was not marked as valid and the cache was
not utilized for subsequent 'ls' operations.
This change uses the file pointer, which remains consistent across all
readdir calls for a given directory instance, to associate and validate
the cache. As a result, cached directory contents can now be
correctly reused, improving performance for repeated directory listings.
Performance gains with local windows SMB server:
Without the patch and default actimeo=1:
1000 directory enumeration operations on dir with 10k files took 135.0s
With this patch and actimeo=0:
1000 directory enumeration operations on dir with 10k files took just 5.1s
Signed-off-by: Bharath SM <bharathsm@microsoft.com>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
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Customer reported that one of their applications started failing to
open files with STATUS_INSUFFICIENT_RESOURCES due to NetApp server
hitting the maximum number of opens to same file that it would allow
for a single client connection.
It turned out the client was failing to reuse open handles with
deferred closes because matching ->f_flags directly without masking
off O_CREAT|O_EXCL|O_TRUNC bits first broke the comparision and then
client ended up with thousands of deferred closes to same file. Those
bits are already satisfied on the original open, so no need to check
them against existing open handles.
Reproducer:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <pthread.h>
#define NR_THREADS 4
#define NR_ITERATIONS 2500
#define TEST_FILE "/mnt/1/test/dir/foo"
static char buf[64];
static void *worker(void *arg)
{
int i, j;
int fd;
for (i = 0; i < NR_ITERATIONS; i++) {
fd = open(TEST_FILE, O_WRONLY|O_CREAT|O_APPEND, 0666);
for (j = 0; j < 16; j++)
write(fd, buf, sizeof(buf));
close(fd);
}
}
int main(int argc, char *argv[])
{
pthread_t t[NR_THREADS];
int fd;
int i;
fd = open(TEST_FILE, O_WRONLY|O_CREAT|O_TRUNC, 0666);
close(fd);
memset(buf, 'a', sizeof(buf));
for (i = 0; i < NR_THREADS; i++)
pthread_create(&t[i], NULL, worker, NULL);
for (i = 0; i < NR_THREADS; i++)
pthread_join(t[i], NULL);
return 0;
}
Before patch:
$ mount.cifs //srv/share /mnt/1 -o ...
$ mkdir -p /mnt/1/test/dir
$ gcc repro.c && ./a.out
...
number of opens: 1391
After patch:
$ mount.cifs //srv/share /mnt/1 -o ...
$ mkdir -p /mnt/1/test/dir
$ gcc repro.c && ./a.out
...
number of opens: 1
Cc: linux-cifs@vger.kernel.org
Cc: David Howells <dhowells@redhat.com>
Cc: Jay Shin <jaeshin@redhat.com>
Cc: Pierguido Lambri <plambri@redhat.com>
Fixes: b8ea3b1ff544 ("smb: enable reuse of deferred file handles for write operations")
Acked-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
In case the BO is in iomem, we can't simply take the vaddr and write to
it. Instead, prepare a separate buffer that is later copied into io
memory. Right now it's just a few words that could be using
xe_map_write32(), but the intention is to grow the WA BB for other
uses.
Fixes: 617d824c5323 ("drm/xe: Add WA BB to capture active context utilization")
Cc: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Link: https://lore.kernel.org/r/20250604-wa-bb-fix-v1-1-0dfc5dafcef0@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
(cherry picked from commit ef48715b2d3df17c060e23b9aa636af3d95652f8)
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
|
|
Add test_rss_default_context_rule() to verify that ntuple rules can
correctly direct traffic to the default RSS context (context 0).
The test creates two ntuple rules with explicit location priorities:
- A high-priority rule (loc 0) directing specific port traffic to
context 0.
- A low-priority rule (loc 1) directing all other TCP traffic to context
1.
This validates that:
1. Rules targeting the default context function properly.
2. Traffic steering works as expected when mixing default and
additional RSS contexts.
The test was written by AI, and reviewed by humans.
Reviewed-by: Nimrod Oren <noren@nvidia.com>
Signed-off-by: Gal Pressman <gal@nvidia.com>
Link: https://patch.msgid.link/20250612071958.1696361-3-gal@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Context 0 (default context) always exists, there is no need to check
whether it exists or not when adding a flow steering rule.
The existing check fails when creating a flow steering rule for context
0 as it is not stored in the rss_ctx xarray.
For example:
$ ethtool --config-ntuple eth2 flow-type tcp4 dst-ip 194.237.147.23 dst-port 19983 context 0 loc 618
rmgr: Cannot insert RX class rule: Invalid argument
Cannot insert classification rule
An example usecase for this could be:
- A high-priority rule (loc 0) directing specific port traffic to
context 0.
- A low-priority rule (loc 1) directing all other TCP traffic to context
1.
This is a user-visible regression that was caught in our testing
environment, it was not reported by a user yet.
Fixes: de7f7582dff2 ("net: ethtool: prevent flow steering to RSS contexts which don't exist")
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Nimrod Oren <noren@nvidia.com>
Signed-off-by: Gal Pressman <gal@nvidia.com>
Reviewed-by: Joe Damato <jdamato@fastly.com>
Reviewed-by: Edward Cree <ecree.xilinx@gmail.com>
Link: https://patch.msgid.link/20250612071958.1696361-2-gal@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Before the cited commit, the kernel unconditionally embedded SCM
credentials to skb for embryo sockets even when both the sender
and listener disabled SO_PASSCRED and SO_PASSPIDFD.
Now, the credentials are added to skb only when configured by the
sender or the listener.
However, as reported in the link below, it caused a regression for
some programs that assume credentials are included in every skb,
but sometimes not now.
The only problematic scenario would be that a socket starts listening
before setting the option. Then, there will be 2 types of non-small
race window, where a client can send skb without credentials, which
the peer receives as an "invalid" message (and aborts the connection
it seems ?):
Client Server
------ ------
s1.listen() <-- No SO_PASS{CRED,PIDFD}
s2.connect()
s2.send() <-- w/o cred
s1.setsockopt(SO_PASS{CRED,PIDFD})
s2.send() <-- w/ cred
or
Client Server
------ ------
s1.listen() <-- No SO_PASS{CRED,PIDFD}
s2.connect()
s2.send() <-- w/o cred
s3, _ = s1.accept() <-- Inherit cred options
s2.send() <-- w/o cred but not set yet
s3.setsockopt(SO_PASS{CRED,PIDFD})
s2.send() <-- w/ cred
It's unfortunate that buggy programs depend on the behaviour,
but let's restore the previous behaviour.
Fixes: 3f84d577b79d ("af_unix: Inherit sk_flags at connect().")
Reported-by: Jacek Łuczak <difrost.kernel@gmail.com>
Closes: https://lore.kernel.org/all/68d38b0b-1666-4974-85d4-15575789c8d4@gmail.com/
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Tested-by: Christian Heusel <christian@heusel.eu>
Tested-by: André Almeida <andrealmeid@igalia.com>
Tested-by: Jacek Łuczak <difrost.kernel@gmail.com>
Link: https://patch.msgid.link/20250611202758.3075858-1-kuni1840@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
syzkaller created an IPv6 route from a malformed packet, which has
a prefix len > 128, triggering the splat below. [0]
This is a similar issue fixed by commit 586ceac9acb7 ("ipv6: Restore
fib6_config validation for SIOCADDRT.").
The cited commit removed fib6_config validation from some callers
of ip6_add_route().
Let's move the validation back to ip6_route_add() and
ip6_route_multipath_add().
[0]:
UBSAN: array-index-out-of-bounds in ./include/net/ipv6.h:616:34
index 20 is out of range for type '__u8 [16]'
CPU: 1 UID: 0 PID: 7444 Comm: syz.0.708 Not tainted 6.16.0-rc1-syzkaller-g19272b37aa4f #0 PREEMPT
Hardware name: riscv-virtio,qemu (DT)
Call Trace:
[<ffffffff80078a80>] dump_backtrace+0x2e/0x3c arch/riscv/kernel/stacktrace.c:132
[<ffffffff8000327a>] show_stack+0x30/0x3c arch/riscv/kernel/stacktrace.c:138
[<ffffffff80061012>] __dump_stack lib/dump_stack.c:94 [inline]
[<ffffffff80061012>] dump_stack_lvl+0x12e/0x1a6 lib/dump_stack.c:120
[<ffffffff800610a6>] dump_stack+0x1c/0x24 lib/dump_stack.c:129
[<ffffffff8001c0ea>] ubsan_epilogue+0x14/0x46 lib/ubsan.c:233
[<ffffffff819ba290>] __ubsan_handle_out_of_bounds+0xf6/0xf8 lib/ubsan.c:455
[<ffffffff85b363a4>] ipv6_addr_prefix include/net/ipv6.h:616 [inline]
[<ffffffff85b363a4>] ip6_route_info_create+0x8f8/0x96e net/ipv6/route.c:3793
[<ffffffff85b635da>] ip6_route_add+0x2a/0x1aa net/ipv6/route.c:3889
[<ffffffff85b02e08>] addrconf_prefix_route+0x2c4/0x4e8 net/ipv6/addrconf.c:2487
[<ffffffff85b23bb2>] addrconf_prefix_rcv+0x1720/0x1e62 net/ipv6/addrconf.c:2878
[<ffffffff85b92664>] ndisc_router_discovery+0x1a06/0x3504 net/ipv6/ndisc.c:1570
[<ffffffff85b99038>] ndisc_rcv+0x500/0x600 net/ipv6/ndisc.c:1874
[<ffffffff85bc2c18>] icmpv6_rcv+0x145e/0x1e0a net/ipv6/icmp.c:988
[<ffffffff85af6798>] ip6_protocol_deliver_rcu+0x18a/0x1976 net/ipv6/ip6_input.c:436
[<ffffffff85af8078>] ip6_input_finish+0xf4/0x174 net/ipv6/ip6_input.c:480
[<ffffffff85af8262>] NF_HOOK include/linux/netfilter.h:317 [inline]
[<ffffffff85af8262>] NF_HOOK include/linux/netfilter.h:311 [inline]
[<ffffffff85af8262>] ip6_input+0x16a/0x70c net/ipv6/ip6_input.c:491
[<ffffffff85af8dcc>] ip6_mc_input+0x5c8/0x1268 net/ipv6/ip6_input.c:588
[<ffffffff85af6112>] dst_input include/net/dst.h:469 [inline]
[<ffffffff85af6112>] ip6_rcv_finish net/ipv6/ip6_input.c:79 [inline]
[<ffffffff85af6112>] NF_HOOK include/linux/netfilter.h:317 [inline]
[<ffffffff85af6112>] NF_HOOK include/linux/netfilter.h:311 [inline]
[<ffffffff85af6112>] ipv6_rcv+0x5ae/0x6e0 net/ipv6/ip6_input.c:309
[<ffffffff85087e84>] __netif_receive_skb_one_core+0x106/0x16e net/core/dev.c:5977
[<ffffffff85088104>] __netif_receive_skb+0x2c/0x144 net/core/dev.c:6090
[<ffffffff850883c6>] netif_receive_skb_internal net/core/dev.c:6176 [inline]
[<ffffffff850883c6>] netif_receive_skb+0x1aa/0xbf2 net/core/dev.c:6235
[<ffffffff8328656e>] tun_rx_batched.isra.0+0x430/0x686 drivers/net/tun.c:1485
[<ffffffff8329ed3a>] tun_get_user+0x2952/0x3d6c drivers/net/tun.c:1938
[<ffffffff832a21e0>] tun_chr_write_iter+0xc4/0x21c drivers/net/tun.c:1984
[<ffffffff80b9b9ae>] new_sync_write fs/read_write.c:593 [inline]
[<ffffffff80b9b9ae>] vfs_write+0x56c/0xa9a fs/read_write.c:686
[<ffffffff80b9c2be>] ksys_write+0x126/0x228 fs/read_write.c:738
[<ffffffff80b9c42e>] __do_sys_write fs/read_write.c:749 [inline]
[<ffffffff80b9c42e>] __se_sys_write fs/read_write.c:746 [inline]
[<ffffffff80b9c42e>] __riscv_sys_write+0x6e/0x94 fs/read_write.c:746
[<ffffffff80076912>] syscall_handler+0x94/0x118 arch/riscv/include/asm/syscall.h:112
[<ffffffff8637e31e>] do_trap_ecall_u+0x396/0x530 arch/riscv/kernel/traps.c:341
[<ffffffff863a69e2>] handle_exception+0x146/0x152 arch/riscv/kernel/entry.S:197
Fixes: fa76c1674f2e ("ipv6: Move some validation from ip6_route_info_create() to rtm_to_fib6_config().")
Reported-by: syzbot+4c2358694722d304c44e@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/6849b8c3.a00a0220.1eb5f5.00f0.GAE@google.com/
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250611193551.2999991-1-kuni1840@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
netdevsim supports netpoll. Make sure we don't call napi_complete()
from it, since it may not be scheduled. Breno reports hitting a
warning in napi_complete_done():
WARNING: CPU: 14 PID: 104 at net/core/dev.c:6592 napi_complete_done+0x2cc/0x560
__napi_poll+0x2d8/0x3a0
handle_softirqs+0x1fe/0x710
This is presumably after netpoll stole the SCHED bit prematurely.
Reported-by: Breno Leitao <leitao@debian.org>
Fixes: 3762ec05a9fb ("netdevsim: add NAPI support")
Tested-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20250611174643.2769263-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Check for if ida_alloc() or rhashtable_lookup_get_insert_fast() fails.
Fixes: 17e0accac577 ("net/mlx5: HWS, support complex matchers")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Yevgeny Kliteynik <kliteyn@nvidia.com>
Link: https://patch.msgid.link/aEmBONjyiF6z5yCV@stanley.mountain
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
The veth peer device is RCU protected, but when the peer device gets
deleted (veth_dellink) then the pointer is assigned NULL (via
RCU_INIT_POINTER).
This patch adds a necessary NULL check in veth_xdp_rcv when accessing
the veth peer net_device.
This fixes a bug introduced in commit dc82a33297fc ("veth: apply qdisc
backpressure on full ptr_ring to reduce TX drops"). The bug is a race
and only triggers when having inflight packets on a veth that is being
deleted.
Reported-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Closes: https://lore.kernel.org/all/fecfcad0-7a16-42b8-bff2-66ee83a6e5c4@linux.dev/
Reported-by: syzbot+c4c7bf27f6b0c4bd97fe@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/683da55e.a00a0220.d8eae.0052.GAE@google.com/
Fixes: dc82a33297fc ("veth: apply qdisc backpressure on full ptr_ring to reduce TX drops")
Signed-off-by: Jesper Dangaard Brouer <hawk@kernel.org>
Acked-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Link: https://patch.msgid.link/174964557873.519608.10855046105237280978.stgit@firesoul
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
This function is no longer used after the four prior fixes.
Given all prior uses were wrong, it seems better to remove it.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250611111515.1983366-6-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Gerrard Tai reported a race condition in ETS, whenever SFQ perturb timer
fires at the wrong time.
The race is as follows:
CPU 0 CPU 1
[1]: lock root
[2]: qdisc_tree_flush_backlog()
[3]: unlock root
|
| [5]: lock root
| [6]: rehash
| [7]: qdisc_tree_reduce_backlog()
|
[4]: qdisc_put()
This can be abused to underflow a parent's qlen.
Calling qdisc_purge_queue() instead of qdisc_tree_flush_backlog()
should fix the race, because all packets will be purged from the qdisc
before releasing the lock.
Fixes: b05972f01e7d ("net: sched: tbf: don't call qdisc_put() while holding tree lock")
Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Suggested-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250611111515.1983366-5-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Gerrard Tai reported a race condition in TBF, whenever SFQ perturb timer
fires at the wrong time.
The race is as follows:
CPU 0 CPU 1
[1]: lock root
[2]: qdisc_tree_flush_backlog()
[3]: unlock root
|
| [5]: lock root
| [6]: rehash
| [7]: qdisc_tree_reduce_backlog()
|
[4]: qdisc_put()
This can be abused to underflow a parent's qlen.
Calling qdisc_purge_queue() instead of qdisc_tree_flush_backlog()
should fix the race, because all packets will be purged from the qdisc
before releasing the lock.
Fixes: b05972f01e7d ("net: sched: tbf: don't call qdisc_put() while holding tree lock")
Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Suggested-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Zhengchao Shao <shaozhengchao@huawei.com>
Link: https://patch.msgid.link/20250611111515.1983366-4-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Gerrard Tai reported a race condition in RED, whenever SFQ perturb timer
fires at the wrong time.
The race is as follows:
CPU 0 CPU 1
[1]: lock root
[2]: qdisc_tree_flush_backlog()
[3]: unlock root
|
| [5]: lock root
| [6]: rehash
| [7]: qdisc_tree_reduce_backlog()
|
[4]: qdisc_put()
This can be abused to underflow a parent's qlen.
Calling qdisc_purge_queue() instead of qdisc_tree_flush_backlog()
should fix the race, because all packets will be purged from the qdisc
before releasing the lock.
Fixes: 0c8d13ac9607 ("net: sched: red: delay destroying child qdisc on replace")
Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Suggested-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250611111515.1983366-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Gerrard Tai reported a race condition in PRIO, whenever SFQ perturb timer
fires at the wrong time.
The race is as follows:
CPU 0 CPU 1
[1]: lock root
[2]: qdisc_tree_flush_backlog()
[3]: unlock root
|
| [5]: lock root
| [6]: rehash
| [7]: qdisc_tree_reduce_backlog()
|
[4]: qdisc_put()
This can be abused to underflow a parent's qlen.
Calling qdisc_purge_queue() instead of qdisc_tree_flush_backlog()
should fix the race, because all packets will be purged from the qdisc
before releasing the lock.
Fixes: 7b8e0b6e6599 ("net: sched: prio: delay destroying child qdiscs on change")
Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Suggested-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250611111515.1983366-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
Gerrard Tai reported that SFQ perturb_period has no range check yet,
and this can be used to trigger a race condition fixed in a separate patch.
We want to make sure ctl->perturb_period * HZ will not overflow
and is positive.
Tested:
tc qd add dev lo root sfq perturb -10 # negative value : error
Error: sch_sfq: invalid perturb period.
tc qd add dev lo root sfq perturb 1000000000 # too big : error
Error: sch_sfq: invalid perturb period.
tc qd add dev lo root sfq perturb 2000000 # acceptable value
tc -s -d qd sh dev lo
qdisc sfq 8005: root refcnt 2 limit 127p quantum 64Kb depth 127 flows 128 divisor 1024 perturb 2000000sec
Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20250611083501.1810459-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
When performing a non-exact phy_caps lookup, we are looking for a
supported mode that matches as closely as possible the passed speed/duplex.
Blamed patch broke that logic by returning a match too early in case
the caller asks for half-duplex, as a full-duplex linkmode may match
first, and returned as a non-exact match without even trying to mach on
half-duplex modes.
Reported-by: Jijie Shao <shaojijie@huawei.com>
Closes: https://lore.kernel.org/netdev/20250603102500.4ec743cf@fedora/T/#m22ed60ca635c67dc7d9cbb47e8995b2beb5c1576
Tested-by: Jijie Shao <shaojijie@huawei.com>
Reviewed-by: Larysa Zaremba <larysa.zaremba@intel.com>
Fixes: fc81e257d19f ("net: phy: phy_caps: Allow looking-up link caps based on speed and duplex")
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20250606094321.483602-1-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
The sqpoll thread is dereferenced with rcu read protection in one place,
so it needs to be annotated as an __rcu type, and should consistently
use rcu helpers for access and assignment to make sparse happy.
Since most of the accesses occur under the sqd->lock, we can use
rcu_dereference_protected() without declaring an rcu read section.
Provide a simple helper to get the thread from a locked context.
Fixes: ac0b8b327a5677d ("io_uring: fix use-after-free of sq->thread in __io_uring_show_fdinfo()")
Signed-off-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20250611205343.1821117-1-kbusch@meta.com
[axboe: fold in fix for register.c]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
After commit a934a57a42f64a4 ("scripts/misc-check: check missing #include
<linux/export.h> when W=1") and 7d95680d64ac8e836c ("scripts/misc-check:
check unnecessary #include <linux/export.h> when W=1"), we get some build
warnings with W=1:
init/main.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
init/initramfs.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
So fix these build warnings for the init code.
Link: https://lkml.kernel.org/r/20250608141235.155206-1-chenhuacai@loongson.cn
Fixes: a934a57a42f6 ("scripts/misc-check: check missing #include <linux/export.h> when W=1")
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Reviewed-by: Masahiro Yamada <masahiroy@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
I have been actively contributing to mTHP and reviewing related patches
for an extended period, and I would like to continue supporting patch
reviews.
Link: https://lkml.kernel.org/r/20250609002442.1856-1-21cnbao@gmail.com
Signed-off-by: Barry Song <baohua@kernel.org>
Acked-by: Zi Yan <ziy@nvidia.com>
Acked-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Acked-by: Dev Jain <dev.jain@arm.com>
Acked-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Nico Pache <npache@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
In
riocm_cdev_ioctl(RIO_CM_CHAN_SEND)
-> cm_chan_msg_send()
-> riocm_ch_send()
cm_chan_msg_send() checks that userspace didn't send too much data but
riocm_ch_send() failed to check that userspace sent sufficient data. The
result is that riocm_ch_send() can write to fields in the rio_ch_chan_hdr
which were outside the bounds of the space which cm_chan_msg_send()
allocated.
Address this by teaching riocm_ch_send() to check that the entire
rio_ch_chan_hdr was copied in from userspace.
Reported-by: maher azz <maherazz04@gmail.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Alexandre Bounine <alex.bou9@gmail.com>
Cc: Linus Torvalds <torvalds@linuxfoundation.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Commit 3ea277194daa ("mm, mprotect: flush TLB if potentially racing with a
parallel reclaim leaving stale TLB entries") described a theoretical race
as such:
"""
Nadav Amit identified a theoretical race between page reclaim and mprotect
due to TLB flushes being batched outside of the PTL being held.
He described the race as follows:
CPU0 CPU1
---- ----
user accesses memory using RW PTE
[PTE now cached in TLB]
try_to_unmap_one()
==> ptep_get_and_clear()
==> set_tlb_ubc_flush_pending()
mprotect(addr, PROT_READ)
==> change_pte_range()
==> [ PTE non-present - no flush ]
user writes using cached RW PTE
...
try_to_unmap_flush()
The same type of race exists for reads when protecting for PROT_NONE and
also exists for operations that can leave an old TLB entry behind such as
munmap, mremap and madvise.
"""
The solution was to introduce flush_tlb_batched_pending() and call it
under the PTL from mprotect/madvise/munmap/mremap to complete any pending
tlb flushes.
However, while madvise_free_pte_range() and
madvise_cold_or_pageout_pte_range() were both retro-fitted to call
flush_tlb_batched_pending() immediately after initially acquiring the PTL,
they both temporarily release the PTL to split a large folio if they
stumble upon one. In this case, where re-acquiring the PTL
flush_tlb_batched_pending() must be called again, but it previously was
not. Let's fix that.
There are 2 Fixes: tags here: the first is the commit that fixed
madvise_free_pte_range(). The second is the commit that added
madvise_cold_or_pageout_pte_range(), which looks like it copy/pasted the
faulty pattern from madvise_free_pte_range().
This is a theoretical bug discovered during code review.
Link: https://lkml.kernel.org/r/20250606092809.4194056-1-ryan.roberts@arm.com
Fixes: 3ea277194daa ("mm, mprotect: flush TLB if potentially racing with a parallel reclaim leaving stale TLB entries")
Fixes: 9c276cc65a58 ("mm: introduce MADV_COLD")
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Jann Horn <jannh@google.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mel Gorman <mgorman <mgorman@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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While an OOM failure in commit_merge() isn't really feasible due to the
allocation which might fail (a maple tree pre-allocation) being 'too small
to fail', we do need to handle this case correctly regardless.
In vma_merge_existing_range(), we can theoretically encounter failures
which result in an OOM error in two ways - firstly dup_anon_vma() might
fail with an OOM error, and secondly commit_merge() failing, ultimately,
to pre-allocate a maple tree node.
The abort logic for dup_anon_vma() resets the VMA iterator to the initial
range, ensuring that any logic looping on this iterator will correctly
proceed to the next VMA.
However the commit_merge() abort logic does not do the same thing. This
resulted in a syzbot report occurring because mlockall() iterates through
VMAs, is tolerant of errors, but ended up with an incorrect previous VMA
being specified due to incorrect iterator state.
While making this change, it became apparent we are duplicating logic -
the logic introduced in commit 41e6ddcaa0f1 ("mm/vma: add give_up_on_oom
option on modify/merge, use in uffd release") duplicates the
vmg->give_up_on_oom check in both abort branches.
Additionally, we observe that we can perform the anon_dup check safely on
dup_anon_vma() failure, as this will not be modified should this call
fail.
Finally, we need to reset the iterator in both cases, so now we can simply
use the exact same code to abort for both.
We remove the VM_WARN_ON(err != -ENOMEM) as it would be silly for this to
be otherwise and it allows us to implement the abort check more neatly.
Link: https://lkml.kernel.org/r/20250606125032.164249-1-lorenzo.stoakes@oracle.com
Fixes: 47b16d0462a4 ("mm: abort vma_modify() on merge out of memory failure")
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reported-by: syzbot+d16409ea9ecc16ed261a@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-mm/6842cc67.a00a0220.29ac89.003b.GAE@google.com/
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Jann Horn <jannh@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Remove outdated VM_DENYWRITE("dw") reference and add missing
VM_LOCKONFAULT("lf") and VM_UFFD_MINOR("ui") flags.
[akpm@linux-foundation.org: add "dp" (VM_DROPPABLE), per Tal]
Link: https://lkml.kernel.org/r/20250607153614.81914-1-wangfushuai@baidu.com
Signed-off-by: wangfushuai <wangfushuai@baidu.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mariano Pache <npache@redhat.com>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Tal Zussman <tz2294@columbia.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Using "@argname@" in kernel-doc produces "argname****" (with "argname" in
bold) in the generated html output, so use the expected kernel-doc
notation of just "@argname" instead.
"Fixes:" lines are added in case Matthew's patch [1] is backported.
Link: https://lkml.kernel.org/r/20250605002337.2842659-1-rdunlap@infradead.org
Link: https://lore.kernel.org/linux-doc/3bc4e779-7a79-42c1-8867-024f643a22fc@infradead.org/T/#m5d2bd9d21fb34f297aa4e7db069f09bc27b89007 [1]
Fixes: 0db9299f48eb ("SG: Move functions to lib/scatterlist.c and add sg chaining allocator helpers")
Fixes: 8d1d4b538bb1 ("scatterlist: inline sg_next()")
Fixes: 18dabf473e15 ("Change table chaining layout")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Unlike the other cases gup_longterm's memfd tests previously skipped the
test when failing to set up the file descriptor to test. Restore this
behavior to avoid hitting failures when hugetlb isn't configured.
Link: https://lkml.kernel.org/r/20250605-selftest-mm-gup-longterm-tweaks-v1-1-2fae34b05958@kernel.org
Fixes: 66bce7afbaca ("selftests/mm: fix test result reporting in gup_longterm")
Signed-off-by: Mark Brown <broonie@kernel.org>
Reported-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Closes: https://lkml.kernel.org/r/a76fc252-0fe3-4d4b-a9a1-4a2895c2680d@lucifer.local
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Tested-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Introduce `CpuId::current()`, a constructor that wraps the C function
`raw_smp_processor_id()` to retrieve the current CPU identifier without
guaranteeing stability.
This function should be used only when the caller can ensure that
the CPU ID won't change unexpectedly due to preemption or migration.
Suggested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
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Use the newly defined `CpuId` abstraction instead of raw CPU numbers.
This also fixes a doctest failure for configurations where `nr_cpu_ids <
4`.
The C `cpumask_{set|clear}_cpu()` APIs emit a warning when given an
invalid CPU number — but only if `CONFIG_DEBUG_PER_CPU_MAPS=y` is set.
Meanwhile, `cpumask_weight()` only considers CPUs up to `nr_cpu_ids`,
which can cause inconsistencies: a CPU number greater than `nr_cpu_ids`
may be set in the mask, yet the weight calculation won't reflect it.
This leads to doctest failures when `nr_cpu_ids < 4`, as the test tries
to set CPUs 2 and 3:
rust_doctest_kernel_cpumask_rs_0.location: rust/kernel/cpumask.rs:180
rust_doctest_kernel_cpumask_rs_0: ASSERTION FAILED at rust/kernel/cpumask.rs:190
Fixes: 8961b8cb3099 ("rust: cpumask: Add initial abstractions")
Reported-by: Miguel Ojeda <ojeda@kernel.org>
Closes: https://lore.kernel.org/rust-for-linux/CANiq72k3ozKkLMinTLQwvkyg9K=BeRxs1oYZSKhJHY-veEyZdg@mail.gmail.com/
Reported-by: Andreas Hindborg <a.hindborg@kernel.org>
Closes: https://lore.kernel.org/all/87qzzy3ric.fsf@kernel.org/
Suggested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
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Only let userspace pass the same addresses that were used in KVM_SET_USER_MEMORY_REGION
(or KVM_SET_USER_MEMORY_REGION2); gpas in the the upper half of the address space
are an implementation detail of TDX and KVM.
Extracted from a patch by Sean Christopherson <seanjc@google.com>.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Bug[*] reported for TDX case when enabling KVM_PRE_FAULT_MEMORY in QEMU.
It turns out that @gpa passed to kvm_mmu_do_page_fault() doesn't have
shared bit set when the memory attribute of it is shared, and it leads
to wrong root in tdp_mmu_get_root_for_fault().
Fix it by embedding the direct bits in the gpa that is passed to
kvm_tdp_map_page(), when the memory of the gpa is not private.
[*] https://lore.kernel.org/qemu-devel/4a757796-11c2-47f1-ae0d-335626e818fd@intel.com/
Reported-by: Xiaoyao Li <xiaoyao.li@intel.com>
Closes: https://lore.kernel.org/qemu-devel/4a757796-11c2-47f1-ae0d-335626e818fd@intel.com/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Message-ID: <20250611001018.2179964-1-xiaoyao.li@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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We normally can't create a new directory with the case-insensitive
option already set - except when we're creating a snapshot.
And if casefolding is enabled filesystem wide, we should still set it
even though not strictly required, for consistency.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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Previously, we only ever logged the filesystem UUID.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
|