Commit Graph

2287 Commits

Author SHA1 Message Date
Linus Torvalds
764e77d868 Locking updates for v7.2:
Futex updates:
 
  - Optimize futex hash bucket access patterns (Peter Zijlstra)
 
  - Large series to address the robust futex unlock race for real,
    by Thomas Gleixner:
 
     "The robust futex unlock mechanism is racy in respect
      to the clearing of the robust_list_head::list_op_pending
      pointer because unlock and clearing the pointer are not
      atomic. The race window is between the unlock and clearing the
      pending op pointer. If the task is forced to exit in this
      window, exit will access a potentially invalid pending op
      pointer when cleaning up the robust list. That happens if
      another task manages to unmap the object containing the lock
      before the cleanup, which results in an UAF. In the worst case
      this UAF can lead to memory corruption when unrelated content
      has been mapped to the same address by the time the access
      happens.
 
      User space can't solve this problem without help from the kernel.
      This series provides the kernel side infrastructure to help it
      along:
 
       1) Combined unlock, pointer clearing, wake-up for the
          contended case
 
       2) VDSO based unlock and pointer clearing helpers with a
          fix-up function in the kernel when user space was interrupted
          within the critical section.
 
     ... with help by André Almeida:
 
      - Add a note about robust list race condition (André Almeida)
      - Add self-tests for robust release operations (André Almeida)
 
 Context analysis updates:
 
  - Implement context analysis for 'struct rt_mutex'.
    (Bart Van Assche)
  - Bump required Clang version to 23 (Marco Elver)
 
 Guard infrastructure updates:
 
  - Series to remove NULL check from unconditional guards
    (Dmitry Ilvokhin)
 
 Lockdep updates:
 
  - Restore self-test migrate_disable() and sched_rt_mutex
    state on PREEMPT_RT (Karl Mehltretter)
 
 Membarriers updates:
 
  - Use per-CPU mutexes for targeted commands (Aniket Gattani)
  - Modernize membarrier_global_expedited with cleanup guards
    (Aniket Gattani)
  - Add rseq stress test for CFS throttle interactions (Aniket Gattani)
 
 percpu-rwsems updates:
 
  - Extract __percpu_up_read() to optimize inlining overhead
    (Dmitry Ilvokhin)
 
 Seqlocks updates:
 
  - Allow UBSAN_ALIGNMENT to fail optimizing (Heiko Carstens)
 
 Lock tracing:
 
  - Add contended_release tracepoint to sleepable locks
    such as mutexes, percpu-rwsems, rtmutexes, rwsems
    and semaphores. (Dmitry Ilvokhin)
 
 MAINTAINERS updates:
 
  - MAINTAINERS: Add RUST [SYNC] entry (Boqun Feng)
 
 Misc updates and fixes by Randy Dunlap, YE WEI-HONG,
 Fabricio Parra, Dmitry Ilvokhin and Peter Zijlstra.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'locking-core-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip

Pull locking updates from Ingo Molnar:
 "Futex updates:

   - Optimize futex hash bucket access patterns (Peter Zijlstra)

   - Large series to address the robust futex unlock race for real, by
     Thomas Gleixner:

      "The robust futex unlock mechanism is racy in respect to the
       clearing of the robust_list_head::list_op_pending pointer because
       unlock and clearing the pointer are not atomic.

       The race window is between the unlock and clearing the pending op
       pointer. If the task is forced to exit in this window, exit will
       access a potentially invalid pending op pointer when cleaning up
       the robust list.

       That happens if another task manages to unmap the object
       containing the lock before the cleanup, which results in an UAF.

       In the worst case this UAF can lead to memory corruption when
       unrelated content has been mapped to the same address by the time
       the access happens.

       User space can't solve this problem without help from the kernel.
       This series provides the kernel side infrastructure to help it
       along:

        1) Combined unlock, pointer clearing, wake-up for the
           contended case

        2) VDSO based unlock and pointer clearing helpers with a
           fix-up function in the kernel when user space was interrupted
           within the critical section.

      ... with help by André Almeida:

        - Add a note about robust list race condition (André Almeida)
        - Add self-tests for robust release operations (André Almeida)

  Context analysis updates:

   - Implement context analysis for 'struct rt_mutex'. (Bart Van Assche)
   - Bump required Clang version to 23 (Marco Elver)

  Guard infrastructure updates:

   - Series to remove NULL check from unconditional guards (Dmitry
     Ilvokhin)

  Lockdep updates:

   - Restore self-test migrate_disable() and sched_rt_mutex state on
     PREEMPT_RT (Karl Mehltretter)

  Membarriers updates:

   - Use per-CPU mutexes for targeted commands (Aniket Gattani)
   - Modernize membarrier_global_expedited with cleanup guards (Aniket
     Gattani)
   - Add rseq stress test for CFS throttle interactions (Aniket Gattani)

  percpu-rwsems updates:

   - Extract __percpu_up_read() to optimize inlining overhead (Dmitry
     Ilvokhin)

  Seqlocks updates:

   - Allow UBSAN_ALIGNMENT to fail optimizing (Heiko Carstens)

  Lock tracing:

   - Add contended_release tracepoint to sleepable locks such as
     mutexes, percpu-rwsems, rtmutexes, rwsems and semaphores (Dmitry
     Ilvokhin)

  MAINTAINERS updates:

   - MAINTAINERS: Add RUST [SYNC] entry (Boqun Feng)

  Misc updates and fixes by Randy Dunlap, YE WEI-HONG, Fabricio Parra,
  Dmitry Ilvokhin and Peter Zijlstra"

* tag 'locking-core-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip: (36 commits)
  locking: Add contended_release tracepoint to sleepable locks
  locking/percpu-rwsem: Extract __percpu_up_read()
  tracing/lock: Remove unnecessary linux/sched.h include
  futex: Optimize futex hash bucket access patterns
  rust: sync: completion: Mark inline complete_all and wait_for_completion
  MAINTAINERS: Add RUST [SYNC] entry
  cleanup: Specify nonnull argument index
  selftests: futex: Add tests for robust release operations
  Documentation: futex: Add a note about robust list race condition
  x86/vdso: Implement __vdso_futex_robust_try_unlock()
  x86/vdso: Prepare for robust futex unlock support
  futex: Provide infrastructure to plug the non contended robust futex unlock race
  futex: Add robust futex unlock IP range
  futex: Add support for unlocking robust futexes
  futex: Cleanup UAPI defines
  x86: Select ARCH_MEMORY_ORDER_TSO
  uaccess: Provide unsafe_atomic_store_release_user()
  futex: Provide UABI defines for robust list entry modifiers
  futex: Move futex related mm_struct data into a struct
  futex: Make futex_mm_init() void
  ...
2026-06-15 14:21:14 +05:30
Jens Axboe
8569503226 io_uring/net: make POLL_FIRST receive side checks consistent
io_recv() and io_recvzc() are the odd ones out, as they checks for
whether POLL_FIRST should be honored before checking if the file is a
socket. It doesn't really matter, but might as well make it consistent
across all receive and send types.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-06-13 06:27:24 -06:00
Jens Axboe
576cce9148 io_uring: remove the per-ctx fallback task_work machinery
With the tctx fallback running its entries directly, the per-ctx
fallback work has a single user left: moving local (DEFER_TASKRUN)
task_work entries out of a ring that is going away. Both of its call
sites are process context and don't hold ->uring_lock, the same
conditions the deferred fallback work itself ran under - so run the
entries in cancel mode right there instead, and rename the helper to
io_cancel_local_task_work() to match what it now does.

With that, ->fallback_llist, ->fallback_work, io_fallback_req_func()
and __io_fallback_tw() can all go away, along with the fallback work
flushing in the ring exit and cancel paths. Requests that get
orphaned by an exiting task now run via the tctx fallback work, which
the ring exit side implicitly waits on through the ctx refs those
requests hold.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-06-13 06:27:20 -06:00
Jens Axboe
df58c21616 io_uring: run the tctx task_work fallback directly
The fallback work drains the tctx queue only to redistribute the entries
into the per-ctx fallback lists, bouncing them through a second
(per-ctx) work item before they finally run. That made sense when the
producer side did the draining and could be in any context, but the
fallback work is a regular process context kworker: it can just run the
entries itself. Reuse the normal run loop - if run from the fallback
kernel thread, ts.cancel will get set, and the work terminated.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-06-13 06:27:15 -06:00
Jens Axboe
de7341ffe4 io_uring: switch normal task_work to a mpscq
Like the local task_work list, the normal (tctx) task_work list is an
llist, and hence needs the O(n) llist_reverse_order() pass before
running entries in queue order. On top of that, capped runs - sqpoll
processing IORING_TW_CAP_ENTRIES_VALUE entries at a time - need the
claimed-but-unprocessed leftovers carried in a separate retry_list,
as they can't be pushed back to the shared list.

Switch tctx->task_list to a mpscq, like what was done for the
DEFER_TASKRUN paths as well.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-06-13 06:27:11 -06:00
Jens Axboe
d46ab2c98a io_uring: switch local task_work to a mpscq
The local (DEFER_TASKRUN) task_work list is an llist, which is LIFO
ordered, and hence __io_run_local_work() has to restore the right
running order with an O(n) llist_reverse_order() pass first. On top of
that, a batch that gets capped by max_events needs the leftover entries
parked on a separate ->retry_llist, as they can't be pushed back to the
shared list.

Switch it to the FIFO mpscq. Adds are wait-free instead of a cmpxchg
retry loop, entries are popped in queue order with no reversal pass,
capping a run simply leaves the remainder on the queue, and
->retry_llist goes away entirely. The consumer cursor, ->work_head,
lives with the rest of the ->uring_lock protected state rather than
next to the queue, so that popping entries doesn't dirty the producer
side cacheline.

For low amounts of task_work, this ends up being a bit more efficient
than the existing scheme. As an example of that, doing multishot
receives for 8 clients has the following task_work overhead:

     1.02%  sock-test  [kernel.kallsyms]  [k] io_req_local_work_add
     0.88%  sock-test  [kernel.kallsyms]  [k] __io_run_local_work_loop
     0.60%  sock-test  [kernel.kallsyms]  [k] llist_reverse_order
     0.14%  sock-test  [kernel.kallsyms]  [k] __io_run_local_work
     2.64% at ~46Gb/sec

and after this change:

     1.08%  sock-test  [kernel.kallsyms]  [k] io_req_local_work_add
     1.03%  sock-test  [kernel.kallsyms]  [k] __io_run_local_work
     2.11% at ~53Gb/sec

which has less overhead even though that test run was faster. For a case
of having 1024 clients on a single ring:

     2.22%  sock-test  [kernel.kallsyms]  [k] llist_reverse_order
     0.84%  sock-test  [kernel.kallsyms]  [k] __io_run_local_work_loop
     0.42%  sock-test  [kernel.kallsyms]  [k] io_req_local_work_add
     0.02%  sock-test  [kernel.kallsyms]  [k] __io_run_local_work
     3.50% at ~24Gb/sec

we start to see the llist reversing taking a considerable amount of
time, and the total add+run task_work overhead is around 3.5%. After
the change:

     0.90%  sock-test  [kernel.kallsyms]  [k] __io_run_local_work
     0.42%  sock-test  [kernel.kallsyms]  [k] io_req_local_work_add
     1.32% at ~26Gb/sec

most of that overhead is gone, and performance is better as well.

Caleb Sander Mateos <csander@purestorage.com> reports that it improves
the performance of a ublk 4kb workload by 4% [1], while testing v1 of
this patchset.

[1] https://lore.kernel.org/io-uring/CADUfDZr-MMYBaP-e+y9+xuRhuiunO2sBTUCmwZyd7AgT8sVtiQ@mail.gmail.com/

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-06-13 06:27:06 -06:00
Jens Axboe
50cb44bd0d io_uring/mpscq: add lockless multi-producer, single-consumer FIFO queue
Local task_work is currently using llists for managing the work,
but that's a LIFO type of list. This means that running this task_work
needs to reverse the list first, to ensure fairness in running the
queued items.

Add a lockless FIFO queued, based on Dmitry Vyukov's intrusive MPSC
node-based queue algorithm, modified with an externally held consumer
cursor and conditional stub reinsertion. See comments in the header.

Producers are wait-free: a push is a single xchg() on the queue tail,
which serializes concurrent producers and defines the FIFO order, plus
a store linking the node to its predecessor. There are no cmpxchg retry
loops, and pushing is safe from any context, including hardirq.

The cost of linked list FIFO ordering is that a push publishes the node
in two steps - the xchg() makes it visible as the new tail before the
subsequent store links it into the chain that is reachable from the
head. A consumer hitting that window gets a NULL from mpscq_pop() while
mpscq_empty() reports false, and must retry later rather than treat the
queue as empty. The window is two instructions wide, but a producer can
get preempted inside it, so the consumer must not busy wait on it.

The consumer side supports a single consumer at a time, with callers
providing their own serialization. A stub node, which also defines the
empty state (tail == stub), allows the consumer to detach the final
node without racing against producer link stores: that node is only
handed out once the stub has been cmpxchg'ed back in as the tail. This
also guarantees that the previous tail returned by mpscq_push() cannot
get freed before that push has linked it, making it always valid for
comparisons.

The consumer cursor is deliberately not part of the queue struct - the
caller owns it and passes it to mpscq_pop(). This is done to separate
the consumer and producers cacheline. The cursor is written for every
popped entry, and keeping it on the same cacheline as ->tail would have
the consumer invalidating the line that producers need for every push.
Keeping it external lets the caller place it with its own consumer side
data instead.

Reviewed-by: Caleb Sander Mateos <csander@purestorage.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-06-13 06:27:00 -06:00
Jens Axboe
ed64f5c546 io_uring: grab RCU read lock marking task run
Not required right now, as io_req_local_work_add() already calls this
helper with the RCU read lock held. But in preparation for that not
being the case, grab it locally.

Reviewed-by: Caleb Sander Mateos <csander@purestorage.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-06-13 06:26:53 -06:00
Linus Torvalds
880b719ca0 io_uring-7.1-20260611
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Merge tag 'io_uring-7.1-20260611' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux

Pull io_uring fixes from Jens Axboe:

 - Tweak for an off-by-one in the CQ ring accounting for the min wait
   support.

 - Don't truncate end buffer length for a bundle, as the transfer might
   not happen. It's not required in the first place, as the completion
   side handles this condition already.

* tag 'io_uring-7.1-20260611' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
  io_uring/wait: fix min_timeout behavior
  io_uring/kbuf: don't truncate end buffer for bundles
2026-06-12 10:49:59 -07:00
Jens Axboe
753f81b3b8 io_uring/zcrx: kill dead 'sock' member in struct io_zcrx_args
This member is only ever assigned, never read. Kill it.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-06-11 17:04:00 -06:00
Jens Axboe
46800585ae io_uring/kbuf: validate ring provided buffer addresses with access_ok()
Commit:

809b997a5c ("x86-64/arm64/powerpc: clean up and rename __copy_from_user_flushcache")

sanitized that any provided copy helper should separately validate
destination and source addresses, but we should also ensure that
anything that is retrieved from a buffer is validated upfront. For ring
provided buffers, always include an access_ok() when grabbing a new
buffer.

Fixes: c7fb19428d ("io_uring: add support for ring mapped supplied buffers")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-06-08 11:03:16 -06:00
Ming Lei
57ed21fad4 io_uring/net: support registered buffer for plain send and recv
So far IORING_RECVSEND_FIXED_BUF is only honoured on the SEND_ZC path,
even though the import wiring is already present for plain send and
completely absent for recv. Targets such as ublk's NBD backend want to
push/pull I/O data directly to/from an io_uring registered buffer over a
plain send/recv on a TCP socket.

Wire IORING_RECVSEND_FIXED_BUF into the plain IORING_OP_SEND and
IORING_OP_RECV paths:

 - Accept the flag in SENDMSG_FLAGS / RECVMSG_FLAGS and, at prep time,
   restrict it to the non-vectorized IORING_OP_SEND / IORING_OP_RECV
   opcodes. It is mutually exclusive with buffer select, bundles and
   (for recv) multishot, and records sqe->buf_index.

 - For recv, set REQ_F_IMPORT_BUFFER in setup so the registered buffer
   is imported lazily at issue time, mirroring the send path.

 - In io_send()/io_recv(), import the registered buffer via
   io_import_reg_buf() (ITER_SOURCE for send, ITER_DEST for recv) and
   clear REQ_F_IMPORT_BUFFER. The resulting bvec iter persists in
   async_data, so MSG_WAITALL partial send/recv retries resume at the
   right offset.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Link: https://patch.msgid.link/20260608142511.659240-2-ming.lei@redhat.com
[axboe: combine flags checks]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-06-08 08:32:43 -06:00
Christian A. Ehrhardt
29fe1bd01b io_uring/wait: fix min_timeout behavior
The wakeup condition if a min timeout is present and has expired is that
at least _one_ CQE was posted. Thus set the cq_tail target to
->cq_min_tail + 1. Without this commit a spurious wakeup can result in a
premature wakeup because io_should_wake() will return true even if _no_
CQE was posted at all.

Cc: Tip ten Brink <tip@tenbrinkmeijs.com>
Fixes: e15cb2200b ("io_uring: fix min_wait wakeups for SQPOLL")
Cc: stable@vger.kernel.org
Signed-off-by: Christian A. Ehrhardt <lk@c--e.de>
Link: https://patch.msgid.link/20260606201120.1441447-1-lk@c--e.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-06-07 16:12:32 -06:00
Jens Axboe
70f4886bcb io_uring/kbuf: don't truncate end buffer for bundles
If buffers have been peeked for a bundle receive, the kernel will
truncate the end buffer, if the available length is shorter than the
buffer itself. This is unnecessary, as applications iterating bundle
receives must always use the minimum size of the buffer length and the
remaining number of bytes in the bundle. The examples in liburing do
that as well, eg examples/proxy.c.

If the kernel does truncate this buffer AND the current transfer fails,
then the buffer will be left with a smaller size than what is otherwise
available.

Just remove the buffer truncation, as it's not necessary in the first
place.

Link: https://lore.kernel.org/io-uring/CAAEr8jbY60noGj1fw_k91UJRBkyiRVoS6=nLhZ7Svwidjn4CAA@mail.gmail.com/
Reported-by: Federico Brasili <federico.brasili@gmail.com>
Cc: stable@vger.kernel.org
Fixes: 35c8711c8f ("io_uring/kbuf: add helpers for getting/peeking multiple buffers")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-06-07 16:11:47 -06:00
Linus Torvalds
c10130c234 io_uring-7.1-20260605
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Merge tag 'io_uring-7.1-20260605' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux

Pull io_uring fix from Jens Axboe:
 "A single fix for a missing flag mask when multishot is used with
  an incrementally consumed buffer ring, potentially leading to
  application confusion because of lack of IORING_CQE_F_BUF_MORE
  consistency"

* tag 'io_uring-7.1-20260605' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
  io_uring/net: inherit IORING_CQE_F_BUF_MORE across bundle recv retries
2026-06-05 13:52:15 -07:00
Clément Léger
ed46f39c47 io_uring/net: inherit IORING_CQE_F_BUF_MORE across bundle recv retries
When a bundle recv retries inside io_recv_finish(), the merge logic OR
the saved cflags from the previous iteration with the cflags returned by
the new iteration:
  cflags = req->cqe.flags | (cflags & CQE_F_MASK);

Bits listed in CQE_F_MASK are inherited from the new iteration, and all
other bits (notably IORING_CQE_F_BUFFER and the buffer ID) come from the
saved cflags. Before this change CQE_F_MASK covered only
IORING_CQE_F_SOCK_NONEMPTY and IORING_CQE_F_MORE.

When using provided buffer rings (IOU_PBUF_RING_INC) with incremental
mode, and bundle recv, io_kbuf_inc_commit() can leave the head ring
entry partially consumed, __io_put_kbufs() then sets
IORING_CQE_F_BUF_MORE on the returned cflags so userspace knows the
buffer ID will be reused for subsequent completions.

Because IORING_CQE_F_BUF_MORE was not in CQE_F_MASK, the merge above
silently dropped it whenever the final retry iteration partially
consumed the buffer, and the subsequent req->cqe.flags = cflags &
~CQE_F_MASK save would have left a stale IORING_CQE_F_BUF_MORE in the
carried-over cflags had one been present. Userspace would then
wrongfully advance it ring head past an entry the kernel still uses.

Add IORING_CQE_F_BUF_MORE to CQE_F_MASK so it is both inherited from the
new iteration into the user-visible CQE and stripped from the saved
cflags between iterations.

Cc: stable@vger.kernel.org
Signed-off-by: Clément Léger <cleger@meta.com>
Assisted-by: Claude:claude-opus-4.6
Fixes: ae98dbf43d ("io_uring/kbuf: add support for incremental buffer consumption")
Link: https://patch.msgid.link/20260604160715.2482972-1-cleger@meta.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-06-05 05:20:25 -06:00
Christoph Hellwig
6bb0009862 mm/slab: improve kmem_cache_alloc_bulk
The kmem_cache_alloc_bulk return value is weird.  It returns the number
of allocated objects, but that must always be 0 or the requested number
based on the implementations and the handling in the callers, but that
assumption is not actually documented anywhere, which confuses automated
review tools.

Fix this by returning a bool if the allocation succeeded and adding a
kerneldoc comment explaining the API.

[rob.clark@oss.qualcomm.com: fixups in
 msm_iommu_pagetable_prealloc_allocate() ]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com> # skbuff
Link: https://patch.msgid.link/20260528093437.2519248-2-hch@lst.de
Signed-off-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
2026-06-03 18:20:43 +02:00
Thomas Gleixner
3ca9595d9f futex: Add support for unlocking robust futexes
Unlocking robust non-PI futexes happens in user space with the following
sequence:

  1)	robust_list_set_op_pending(mutex);
  2)	robust_list_remove(mutex);

  	lval = 0;
  3)	lval = atomic_xchg(lock, lval);
  4)	if (lval & WAITERS)
  5)		sys_futex(WAKE,....);
  6)	robust_list_clear_op_pending();

That opens a window between #3 and #6 where the mutex could be acquired by
some other task which observes that it is the last user and:

  A) unmaps the mutex memory
  B) maps a different file, which ends up covering the same address

When the original task exits before reaching #6 then the kernel robust list
handling observes the pending op entry and tries to fix up user space.

In case that the newly mapped data contains the TID of the exiting thread
at the address of the mutex/futex the kernel will set the owner died bit in
that memory and therefore corrupting unrelated data.

PI futexes have a similar problem both for the non-contented user space
unlock and the in kernel unlock:

  1)	robust_list_set_op_pending(mutex);
  2)	robust_list_remove(mutex);

  	lval = gettid();
  3)	if (!atomic_try_cmpxchg(lock, lval, 0))
  4)		sys_futex(UNLOCK_PI,....);
  5)	robust_list_clear_op_pending();

Address the first part of the problem where the futexes have waiters and
need to enter the kernel anyway. Add a new FUTEX_ROBUST_UNLOCK flag, which
is valid for the sys_futex() FUTEX_UNLOCK_PI, FUTEX_WAKE, FUTEX_WAKE_BITSET
operations.

This deliberately omits FUTEX_WAKE_OP from this treatment as it's unclear
whether this is needed and there is no usage of it in glibc either to
investigate.

For the futex2 syscall family this needs to be implemented with a new
syscall.

The sys_futex() case [ab]uses the @uaddr2 argument to hand the pointer to
robust_list_head::list_pending_op into the kernel. This argument is only
evaluated when the FUTEX_ROBUST_UNLOCK bit is set and is therefore backward
compatible.

This is an explicit argument to avoid the lookup of the robust list pointer
and retrieving the pending op pointer from there. User space has the
pointer already available so it can just put it into the @uaddr2
argument. Aside of that this allows the usage of multiple robust lists in
the future without any changes to the internal functions as they just operate
on the provided pointer.

This requires a second flag FUTEX_ROBUST_LIST32 which indicates that the
robust list pointer points to an u32 and not to an u64. This is required
for two reasons:

    1) sys_futex() has no compat variant

    2) The gaming emulators use both both 64-bit and compat 32-bit robust
       lists in the same 64-bit application

As a consequence 32-bit applications have to set this flag unconditionally
so they can run on a 64-bit kernel in compat mode unmodified. 32-bit
kernels return an error code when the flag is not set. 64-bit kernels will
happily clear the full 64 bits if user space fails to set it.

In case of FUTEX_UNLOCK_PI this clears the robust list pending op when the
unlock succeeded. In case of errors, the user space value is still locked
by the caller and therefore the above cannot happen.

In case of FUTEX_WAKE* this does the unlock of the futex in the kernel and
clears the robust list pending op when the unlock was successful. If not,
the user space value is still locked and user space has to deal with the
returned error. That means that the unlocking of non-PI robust futexes has
to use the same try_cmpxchg() unlock scheme as PI futexes.

If the clearing of the pending list op fails (fault) then the kernel clears
the registered robust list pointer if it matches to prevent that exit()
will try to handle invalid data. That's a valid paranoid decision because
the robust list head sits usually in the TLS and if the TLS is not longer
accessible then the chance for fixing up the resulting mess is very close
to zero.

The problem of non-contended unlocks still exists and will be addressed
separately.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: André Almeida <andrealmeid@igalia.com>
Link: https://patch.msgid.link/20260602090535.670514505@kernel.org
2026-06-03 11:38:51 +02:00
Gabriel Krisman Bertazi
1f826f2db9 io_uring/nop: Drop a wrong comment in struct io_nop
This was copy-pasted from io_rw, where the comment actually makes sense.
Here, we don't have struct kiocb. Drop the comment.

Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
Link: https://patch.msgid.link/20260602215327.1885109-4-krisman@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-06-02 17:43:20 -06:00
Gabriel Krisman Bertazi
4305fcf9c3 io_uring/net: Remove async_size for OP_LISTEN
OP_LISTEN does not use async_data. Remove it.

Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
Link: https://patch.msgid.link/20260602215327.1885109-3-krisman@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-06-02 17:43:15 -06:00
Gabriel Krisman Bertazi
3979840cd8 io_uring/net: Avoid msghdr on op_connect/op_bind async data
Both IORING_OP_CONNECT and IORING_OP_BIND reuse the msghdr object just
to store the sockaddr. Beyond allocating a much larger object than
needed, msghdr can also wrap an iovec, which will be recycled
unnecessarily. This uses the sockaddr directly.

Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
Link: https://patch.msgid.link/20260602215327.1885109-2-krisman@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-06-02 17:43:06 -06:00
Pavel Begunkov
ec02fe217f io_uring/bpf-ops: restrict ctx access to BPF
BPF programs should have no need in looking into struct io_ring_ctx, if
anything, most of such cases would be anti patterns like looking up ring
indices directly via the context.

Replace it with a new empty structure, which is just an alias to struct
io_ring_ctx. It'll create a new BTF type and fail verification if a BPF
program tries to access it (beyond the first byte). It'll also give more
flexibility for the future, and otherwise it can be made aligned with
io_ring_ctx as before with struct groups if ever needed or extended in a
different way.

Fixes: d0e437b76b ("io_uring/bpf-ops: implement loop_step with BPF struct_ops")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/5f6ca3649e9e0bae8667db4357e28dd00cd07901.1780394491.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-06-02 11:20:21 -06:00
Linus Torvalds
80169db922 io_uring-7.1-20260529
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Merge tag 'io_uring-7.1-20260529' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux

Pull io_uring fix from Jens Axboe:
 "Just a single fix for a regression introduced in this cycle, where
  we should ensure the node is visible before the entry is added to
  the tctx list"

* tag 'io_uring-7.1-20260529' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
  io_uring/tctx: set ->io_uring before publishing the tctx node
2026-05-29 10:36:57 -07:00
Matthew Wilcox (Oracle)
ca36c1aaee block: Add bvec_folio()
This is a simple helper which replaces page_folio(bvec->bv_page).
Minor improvement in readability, but the real motivation is to reduce
the number of references to bvec->bv_page so that it can be changed
with less work.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Leon Romanovsky <leon@kernel.org>
Reviewed-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@linux.dev>
Link: https://patch.msgid.link/20260528175905.1102280-2-willy@infradead.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-29 05:34:24 -06:00
Demi Marie Obenour
fcc77d33a3 net: Remove support for AIO on sockets
The only user of msg->msg_iocb was AF_ALG, but that's deprecated.
It can be removed entirely at the cost of only supporting synchronous
operations.  This doesn't break userspace, which will silently block
(for a bounded amount of time) in io_submit instead of operating
asynchronously.

This also makes struct msghdr smaller, helping every other caller of
sendmsg().

Signed-off-by: Demi Marie Obenour <demiobenour@gmail.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2026-05-29 14:05:30 +08:00
Runyu Xiao
29bef9934b io_uring/io-wq: re-check IO_WQ_BIT_EXIT for each linked work item
commit 10dc959398 ("io_uring/io-wq: check IO_WQ_BIT_EXIT inside work
run loop") fixed the obvious case where io_worker_handle_work() took one
exit-bit snapshot before draining pending work, but the fix stops one
level too early.

io_worker_handle_work() now re-checks IO_WQ_BIT_EXIT in its outer work
run loop, yet it still snapshots that bit once before processing a whole
dependent linked-work chain. If io_wq_exit_start() sets IO_WQ_BIT_EXIT
after the first linked item has started, the remaining linked items can
still reuse stale do_kill = false, skip IO_WQ_WORK_CANCEL, and continue
running after exit has begun.

Move the check further inside, so it covers linked items too. Note: this
is a syzbot special as it loves setting up tons of slow linked work on
weird devices like msr that take forever to read, and immediately close
the ring. Exit then takes a long time.

Fixes: 10dc959398 ("io_uring/io-wq: check IO_WQ_BIT_EXIT inside work run loop")
Cc: stable@vger.kernel.org
Signed-off-by: Runyu Xiao <runyu.xiao@seu.edu.cn>
Link: https://patch.msgid.link/20260527172203.2043962-1-runyu.xiao@seu.edu.cn
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-28 08:06:22 -06:00
liyouhong
ca55f98d6f io_uring/kbuf: align legacy buffer add limit with MAX_BIDS_PER_BGID
io_provide_buffers_prep() accepts nbufs up to MAX_BIDS_PER_BGID, but
io_add_buffers() stops when bl->nbufs reaches USHRT_MAX. This makes the
effective add limit one lower than the validated limit.

Use MAX_BIDS_PER_BGID in the add-side boundary check so validation and
execution use the same limit, and update the comment to refer to the
actual limit constant.

Signed-off-by: liyouhong <liyouhong@kylinos.cn>
Link: https://patch.msgid.link/20260528024936.3672659-1-dayou5941@163.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-28 08:02:57 -06:00
Clément Léger
6935f63146 io_uring/zcrx: add shared-memory notification statistics
Add support for an optional stats struct embedded in the refill queue
region, allowing userspace to monitor copy-fallback in real-time.

Userspace queries the stats struct size and alignment via
IO_URING_QUERY_ZCRX_NOTIF (notif_stats_size / notif_stats_alignment),
then provides a stats_offset in zcrx_notification_desc pointing to a
location within the refill queue region.

The kernel updates the stats counters in-place on every copy-fallback
event.

Signed-off-by: Clément Léger <cleger@meta.com>
[pavel: rename io_uring_zcrx_notif_stats]
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/f6af5a21015efea4b733b9d77aba22c637788fe4.1779189667.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-26 10:42:01 -06:00
Clément Léger
255180f703 io_uring/zcrx: notify user on frag copy fallback
Add a ZCRX_NOTIF_COPY notification type to signal userspace when a
received fragment could not be delivered using zero-copy and was
instead copied into a buffer.

Signed-off-by: Clément Léger <cleger@meta.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/3d54bcd8bf10b3a1e88beb0cd39c40c3937bea4f.1779189667.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-26 10:42:01 -06:00
Pavel Begunkov
0719e10d82 io_uring/zcrx: notify user when out of buffers
There are currently no easy ways for the user to know if zcrx is out of
buffers and page pool fails to allocate. Add uapi for zcrx to communicate
it back.

It's implemented as a separate CQE, which for now is posted to the creator
ctx. To use it, on registration the user space needs to pass an instance
of struct zcrx_notification_desc, which tells the kernel the user_data
for resulting CQEs and which event types are expected / allowed.

When an allowed event happens, zcrx will post a CQE containing the
specified user_data, and lower bits of cqe->res will be set to the event
mask. Before the kernel could post another notification of the given
type, the user needs to acknowledge that it processed the previous one
by issuing IORING_REGISTER_ZCRX_CTRL with ZCRX_CTRL_ARM_NOTIFICATION.

The only notification type the patch implements is
ZCRX_NOTIF_NO_BUFFERS, but we'll need more of them in the future.

Co-developed-by: Vishwanath Seshagiri <vishs@meta.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Vishwanath Seshagiri <vishs@meta.com>
Link: https://patch.msgid.link/35cd307a03a43583838a2e151fc641c69abd786f.1779189667.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-26 10:42:01 -06:00
Pavel Begunkov
8503f2de11 io_uring/zcrx: add ctx pointer to zcrx
zcrx will need to have a pointer to an owning ctx to communicate
different events. Reference the ctx while it's attached to zcrx, and
rely on zcrx termination to drop the ctx to avoid circular ref deps.

Co-developed-by: Vishwanath Seshagiri <vishs@meta.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Vishwanath Seshagiri <vishs@meta.com>
Link: https://patch.msgid.link/b60514b3d1bd92f571e3bd91751166f8c3599256.1779189667.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-26 10:42:01 -06:00
Bertie Tryner
84f7d0931c io_uring/zcrx: reorder fd allocation in zcrx_export()
Currently, zcrx_export() allocates a file descriptor and copies the
control structure to userspace before the backing file is created.

While the operation returns an error on failure, it is cleaner to
follow the standard kernel pattern of performing the copy_to_user()
and fd_install() only after all resource allocations (like the
anon_inode) have succeeded. This aligns the code with other
fd-publishing paths in the VFS.

Signed-off-by: Bertie Tryner <Bertie.Tryner@warwick.ac.uk>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/1513a3f4ae7161692ca6e991b9f01278a6bc60e4.1779189667.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-26 10:42:01 -06:00
Pavel Begunkov
98f07b0f74 io_uring/zcrx: remove extra ifq close
By the time io_zcrx_ifq_free() is called the interface queue should
already be closed, so io_close_queue() will be a no-op. Remove the call
and add a couple of warnings.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/be6c4a283a5bab5440e22fbccafe7b885acb7abc.1779189667.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-26 10:42:01 -06:00
Pavel Begunkov
e57b44039b io_uring/zcrx: poison pointers on unregistration
Nobody should be touching area and other pointers after zcrx
destruction, poison them instead of zeroing.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/19112d1412539dcfc04a0317b5812e968623bc51.1779189667.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-26 10:42:01 -06:00
Pavel Begunkov
74fc9a9b50 io_uring/zcrx: make scrubbing more reliable
Currently, scrubbing is done once before killing all recvzc requests.
It's fine as those are cancelled and don't return buffers afterwards,
but it'll be more reliable not to rely that much on cancellations.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/c4ea127023494cbbedebd21a2b7ae5ff0448eb95.1779189667.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-26 10:42:00 -06:00
Lim HyeonJun
a88c02915d io_uring/tctx: set ->io_uring before publishing the tctx node
io_register_iowq_max_workers() walks ctx->tctx_list under ctx->tctx_lock
and dereferences each node's task->io_uring without a NULL check:

list_for_each_entry(node, &ctx->tctx_list, ctx_node) {
	tctx = node->task->io_uring;
	if (WARN_ON_ONCE(!tctx->io_wq))
		continue;
	...
}

__io_uring_add_tctx_node() installs the node into ctx->tctx_list (via
io_tctx_install_node(), which does the list_add() under tctx_lock) and
only assigns current->io_uring = tctx afterwards. A task doing its first
io_uring operation on a shared ring therefore has a window in which its
node is already visible on ctx->tctx_list while node->task->io_uring is
still NULL. A concurrent IORING_REGISTER_IOWQ_MAX_WORKERS on the same
ring reads that NULL and dereferences tctx->io_wq:

  KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
  RIP: io_register_iowq_max_workers io_uring/register.c:423

Publish current->io_uring = tctx before installing the node, so any node
visible on ctx->tctx_list always has a valid task->io_uring.

Fixes: 7880174e1e ("io_uring/tctx: clean up __io_uring_add_tctx_node() error handling")
Signed-off-by: Lim HyeonJun <shja0831@gmail.com>
Link: https://patch.msgid.link/20260524110853.115634-1-shja0831@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-24 12:01:15 -06:00
Linus Torvalds
dbae42cfa6 io_uring-7.1-20260522
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Merge tag 'io_uring-7.1-20260522' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux

Pull io_uring fixes from Jens Axboe:

 - Fix for an issue with IORING_OP_NOP and using injection results

 - Fix for an issue in IORING_OP_WAITID, where the info state was
   assumed cleared by the lower level syscall handler, but for some
   cases it is not. Just clear the data upfront, so that non-initialized
   data isn't copied back to userspace

 - Fix for a lockdep reported issue, where IORING_OP_BIND enters file
   create and hence hits mnt_want_write(), which creates a three part
   lockdep cycle between the super lock, io_uring's uring_lock, and the
   cred mutex

 - Fix a regression introduced in this cycle with how linked timeouts
   are deleted

 - Ensure that the ->opcode nospec indexing on the opcode issue side
   covers all the cases

* tag 'io_uring-7.1-20260522' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
  io_uring/nop: pass all errors to userspace
  io_uring/timeout: splice timed out link in timeout handler
  io_uring: propagate array_index_nospec opcode into req->opcode
  io_uring/waitid: clear waitid info before copying it to userspace
  io_uring/net: punt IORING_OP_BIND async if it needs file create
2026-05-22 11:53:28 -07:00
Alexander A. Klimov
e97ff8b62d io_uring/nop: pass all errors to userspace
This fixes an inconsistency where io_nop() called req_set_fail()
based on ret, but passed just nop->result to userspace.
Originally, ret is a even copy of nop->result, but is set to an error
when such happens subsequently. Now that's also passed to userspace.

Fixes: a85f31052b ("io_uring/nop: add support for testing registered files and buffers")
Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Link: https://patch.msgid.link/20260520180045.538533-1-grandmaster@al2klimov.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-21 11:10:56 -06:00
Jens Axboe
3d879647fb io_uring/timeout: splice timed out link in timeout handler
A previous commit deferred this to the task_work part of it, so it could
be protected by ->uring_lock. But that's actually not necessary here,
and in fact the head clearing is not enough to make that safe. For those
two reasons, just re-instate the local splicing.

Fixes: 49ae66eb8c ("io_uring: defer linked-timeout chain splice out of hrtimer context")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-20 10:02:58 -06:00
Michael Bommarito
cf18e36455 io_uring: propagate array_index_nospec opcode into req->opcode
Commit 1e988c3fe1 ("io_uring: prevent opcode speculation") added
array_index_nospec() to io_init_req(), but applied it only to a local
opcode variable. req->opcode is initialized from sqe->opcode before the
bounds check and remains the raw value.

Keep req->opcode as the canonical opcode in io_init_req(): reject
out-of-range values architecturally, then write the array_index_nospec()
result back to req->opcode before any table lookup. This keeps downstream
users of req->opcode from observing the raw user byte on a mispredicted
path.

No functional change: array_index_nospec() is a no-op for opcodes in
[0, IORING_OP_LAST), and out-of-range opcodes are still rejected at the
bounds check above the assignment.

Fixes: 1e988c3fe1 ("io_uring: prevent opcode speculation")
Assisted-by: Claude:claude-opus-4-7
Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com>
Link: https://patch.msgid.link/20260517213010.696135-1-michael.bommarito@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-18 08:59:12 -06:00
Heechan Kang
93d93f5f8d io_uring/waitid: clear waitid info before copying it to userspace
IORING_OP_WAITID stores its result fields in struct io_waitid::info and
later copies them to userspace siginfo. The prep path initializes the
request arguments, but it does not initialize info itself.

If the wait operation completes without reporting a child event, the common
wait code can return without writing wo_info. In that case io_waitid_finish()
still copies iw->info to userspace, exposing stale bytes from the reused
io_kiocb command storage.

Clear the result storage during prep so the io_uring path matches the
regular waitid syscall, which uses a zero-initialized struct waitid_info.

Fixes: f31ecf671d ("io_uring: add IORING_OP_WAITID support")
Cc: stable@vger.kernel.org # 6.7+
Signed-off-by: Heechan Kang <gganji11@naver.com>
Link: https://patch.msgid.link/20260516184709.852814-1-gganji11@naver.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-16 12:58:21 -06:00
Linus Torvalds
ee7226b2ae io_uring-7.1-20260515
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Merge tag 'io_uring-7.1-20260515' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux

Pull io_uring fixes from Jens Axboe:

 - Small series sanitizing the locking done for either modifying or
   reading a chain of requests

 - If the application has a pid namespace, ensure that the sqthread pid
   is correctly printed in fdinfo

 - Fix for a hashing issue in the io-wq thread pool, which could lead to
   a use-after-free

 - Kill dead argument from io_prep_rw_pi()

 - Fix for a missed validation of the CQ ring head, affecting CQE refill

* tag 'io_uring-7.1-20260515' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
  io_uring: validate user-controlled cq.head in io_cqe_cache_refill()
  io-wq: check that the predecessor is hashed in io_wq_remove_pending()
  io_uring/rw: drop unused attr_type_mask from io_prep_rw_pi()
  io_uring: hold uring_lock across io_kill_timeouts() in cancel path
  io_uring: defer linked-timeout chain splice out of hrtimer context
  io_uring: hold uring_lock when walking link chain in io_wq_free_work()
  io_uring/fdinfo: translate SqThread PID through caller's pid_ns
2026-05-15 12:34:02 -07:00
Jens Axboe
ccd25890f7 io_uring/net: punt IORING_OP_BIND async if it needs file create
For two reasons:

1) An opcode cannot block inside io_uring_enter() doing submissions, as
   it'll stall the submission side pipeline.

2) Ending up in sb_start_write() -> __sb_start_write() ->
   percpu_down_read_freezable() introduces a new lockdep edge, which it
   correctly complains about.

Check if the socket type is AF_UNIX and has a non-empty pathname. If it
does, mark it REQ_F_FORCE_ASYNC to punt the submission to io-wq rather
than attempt to do it inline.

Fixes: 7481fd93fa ("io_uring: Introduce IORING_OP_BIND")
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-15 11:02:16 -06:00
Jens Axboe
cfa1539b24 io_uring/epoll: disallow adding an epoll file to an epoll context
One of the nastier things about epoll is how it allows adding epoll
files to epoll contexts. This leads to all sorts of loop detection
code, and has been a source of issues in the past.

Arguably adding IORING_EPOLL_CTL is a historical mistake on the
io_uring side, but we're kind of stuck with it now as it does seem
to be in use according to code searches. But we can at least minimize
the damage a bit and just disallow this part of epoll, where nesting
issues can arise.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-15 09:57:41 -06:00
Jens Axboe
071858de47 io_uring/epoll: switch to using do_epoll_ctl_file() interface
No functional changes in this patch.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-15 09:57:37 -06:00
Vineeth Pillai
67ee1f021a io_uring: Use trace_call__##name() at guarded tracepoint call sites
Replace trace_foo() with the new trace_call__foo() at sites already
guarded by trace_foo_enabled(), avoiding a redundant
static_branch_unlikely() re-evaluation inside the tracepoint.
trace_call__foo() calls the tracepoint callbacks directly without
utilizing the static branch again.

Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Vineeth Pillai (Google) <vineeth@bitbyteword.org>
Assisted-by: Claude:claude-sonnet-4-6
Link: https://patch.msgid.link/20260515135903.2238731-1-vineeth@bitbyteword.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-15 08:05:26 -06:00
Jens Axboe
b4e41050b2 io_uring/rsrc: raise registered buffer 1GB limit
There's no real reason to have a limit, as the memory is accounted by
the lockmem limits anyway, if any exist. io_pin_pages() will still
restrict the maximum allowed limit per buffer, which is INT_MAX
number of pages. Cap it a bit lower than that, at 1TB for a 64-bit
system. Surely that should be enough for everyone. For now.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-14 08:12:29 -06:00
Jens Axboe
ca76b56a2a io_uring/rsrc: bump struct io_mapped_ubuf length field to size_t
In preparation for supporting bigger individual buffers, bump the length
field to a full 8-bytes with size_t rather than an unsigned int.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-14 08:12:23 -06:00
Jens Axboe
df0a52537c io_uring/rsrc: add huge page accounting for registered buffers
Track huge page references in a per-ring xarray to prevent double
accounting when the same huge page is used by multiple registered
buffers, either within the same ring or across cloned rings.

When registering buffers backed by huge pages, we need to account for
RLIMIT_MEMLOCK. But if multiple buffers share the same huge page (common
with cloned buffers), we must not account for the same page multiple
times. Similarly, we must only unaccount when the last reference to a
huge page is released.

Maintain a per-ring xarray (hpage_acct) that tracks reference counts for
each huge page. When registering a buffer, for each unique huge page,
increment its accounting reference count, and only account pages that
are newly added.

When unregistering a buffer, for each unique huge page, decrement its
refcount. Once the refcount hits zero, the page is unaccounted.

Note: any account is done against the ctx->user that was assigned when
the ring was setup. As before, if root is running the operation, no
accounting is done.

With these changes, any use of imu->acct_pages is also dead, hence kill
it from struct io_mapped_ubuf. This shrinks it from 56b to 48b on a
64-bit arch. Additionally, hpage_already_acct() is gone, which was an
O(M*M) scan over current + previous registrations.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-14 08:11:53 -06:00
Shouvik Kar
899bea8248 io_uring/net: allow filtering on IORING_OP_CONNECT
This adds custom filtering for IORING_OP_CONNECT, where the target
family is always exposed, and (for AF_INET / AF_INET6) port and
address are exposed. port and v4_addr are in network byte order so
filter authors can compare against on-wire constants.

Skip population unless addr_len covers the populated fields, to
avoid leaking stale io_async_msghdr data on short connects.

Signed-off-by: Shouvik Kar <auxcorelabs@gmail.com>
Link: https://patch.msgid.link/20260512110242.26219-1-auxcorelabs@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-14 07:23:01 -06:00
Yi Xie
c84701cfc9 io_uring: parenthesize io_ring_head_to_buf() expansion
Wrap the io_ring_head_to_buf() macro value in an extra pair of parentheses
so it is safe when composed into larger expressions, and to satisfy
scripts/checkpatch.pl.

Signed-off-by: Yi Xie <xieyi@kylinos.cn>
Link: https://patch.msgid.link/20260514083443.203387-1-xieyi@kylinos.cn
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-14 07:21:32 -06:00
Zizhi Wo
f44d38a31f io_uring: validate user-controlled cq.head in io_cqe_cache_refill()
A fuzzing run reproduced an unkillable io_uring task stuck at ~100% CPU:

[root@fedora io_uring_stress]# ps -ef | grep io_uring
root  1240  1  99 13:36 ?  00:01:35 [io_uring_stress] <defunct>

The task loops inside io_cqring_wait() and never returns to userspace,
and SIGKILL has no effect.

This is caused by the CQ ring exposing rings->cq.head to userspace as
writable, while the authoritative tail lives in kernel-private
ctx->cached_cq_tail. io_cqe_cache_refill() computes free space as an
unsigned subtraction:

    free = ctx->cq_entries - min(tail - head, ctx->cq_entries);

If userspace keeps head within [0, tail], the subtraction is well
defined and min() just acts as a defensive clamp. But if userspace
advances head past tail, (tail - head) wraps to a huge value, free
becomes 0, and io_cqe_cache_refill() fails. The CQE is pushed onto the
overflow list and IO_CHECK_CQ_OVERFLOW_BIT is set.

The wait loop in io_cqring_wait() relies on an invariant: refill() only
fails when the CQ is *physically* full, in which case rings->cq.tail has
been advanced to iowq->cq_tail and io_should_wake() returns true. The
tampered head breaks this: refill() fails while the ring is not full, no
OCQE is copied in, rings->cq.tail never catches up, io_should_wake()
stays false, and io_cqring_wait_schedule() keeps returning early because
IO_CHECK_CQ_OVERFLOW_BIT is still set. The result is a tight retry loop
that never returns to userspace.

Introduce io_cqring_queued() as the single point that converts the
(tail, head) pair into a trustworthy queued count. Since the real
head/tail distance is bounded by cq_entries (far below 2^31), a signed
comparison reliably detects userspace moving head past tail; in that
case treat the queue as empty so callers see the full cache as free and
forward progress is preserved.

Suggested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Zizhi Wo <wozizhi@huawei.com>
Link: https://patch.msgid.link/20260514021847.4062782-1-wozizhi@huaweicloud.com
[axboe: fixup commit message, kill 'queued' var, and keep it all in
io_uring.c]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-13 21:44:57 -06:00
Nicholas Carlini
d6a2d7b04b io-wq: check that the predecessor is hashed in io_wq_remove_pending()
io_wq_remove_pending() needs to fix up wq->hash_tail[] if the cancelled
work was the tail of its hash bucket. When doing this, it checks whether
the preceding entry in acct->work_list has the same hash value, but
never checks that the predecessor is hashed at all. io_get_work_hash()
is simply atomic_read(&work->flags) >> IO_WQ_HASH_SHIFT, and the hash
bits are never set for non-hashed work, so it returns 0. Thus, when a
hashed bucket-0 work is cancelled while a non-hashed work is its list
predecessor, the check spuriously passes and a pointer to the non-hashed
io_kiocb is stored in wq->hash_tail[0].

Because non-hashed work is dequeued via the fast path in
io_get_next_work(), which never touches hash_tail[], the stale pointer
is never cleared. Therefore, after the non-hashed io_kiocb completes and
is freed back to req_cachep, wq->hash_tail[0] is a dangling pointer. The
io_wq is per-task (tctx->io_wq) and survives ring open/close, so the
dangling pointer persists for the lifetime of the task; the next hashed
bucket-0 enqueue dereferences it in io_wq_insert_work() and
wq_list_add_after() writes through freed memory.

Add the missing io_wq_is_hashed() check so a non-hashed predecessor
never inherits a hash_tail[] slot.

Cc: stable@vger.kernel.org
Fixes: 204361a77f ("io-wq: fix hang after cancelling pending hashed work")
Signed-off-by: Nicholas Carlini <nicholas@carlini.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-13 13:06:37 -06:00
Yang Xiuwei
5f7c7c63ff io_uring/rw: drop unused attr_type_mask from io_prep_rw_pi()
io_prep_rw_pi() never used the attr_type_mask argument. Callers already
validate sqe->attr_type_mask before invoking the helper (only
IORING_RW_ATTR_FLAG_PI is supported today). Remove the dead parameter to
avoid implying further interpretation happens here.

Signed-off-by: Yang Xiuwei <yangxiuwei@kylinos.cn>
Link: https://patch.msgid.link/20260513094303.866533-1-yangxiuwei@kylinos.cn
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-13 06:35:57 -06:00
Jens Axboe
a65855ec34 io_uring: hold uring_lock across io_kill_timeouts() in cancel path
io_uring_try_cancel_requests() dropped ctx->uring_lock before calling
io_kill_timeouts(), which walks each timeout's link chain via
io_match_task() to test REQ_F_INFLIGHT. With chain mutation now
serialized by ctx->uring_lock, that walk needs the lock too.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-11 11:14:38 -06:00
Jens Axboe
49ae66eb8c io_uring: defer linked-timeout chain splice out of hrtimer context
io_link_timeout_fn() is the hrtimer callback that fires when a linked
timeout expires. It currently calls io_remove_next_linked(prev) under
ctx->timeout_lock to splice the timeout request out of the link chain.
This is the only chain-mutation site that runs without ctx->uring_lock,
because hrtimer callbacks cannot take a mutex. Defer the splicing until
the task_work callback.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-11 11:14:34 -06:00
Jens Axboe
20c39819a2 io_uring: hold uring_lock when walking link chain in io_wq_free_work()
io_wq_free_work() calls io_req_find_next() from io-wq worker context,
which reads and clears req->link without holding any lock. This can
potentially race with other paths that mutate the same chain under
ctx->uring_lock.

Take ctx->uring_lock around the io_req_find_next() call. Only requests
with IO_REQ_LINK_FLAGS reach this path, which is not the hot path.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-11 11:14:29 -06:00
Maoyi Xie
3799c25709 io_uring/fdinfo: translate SqThread PID through caller's pid_ns
SQPOLL stores current->pid (init_pid_ns view) in sqd->task_pid
at thread creation. fdinfo prints it raw via
seq_printf("SqThread:\t%d\n", sq_pid). A reader inside a
non-initial pid_ns sees the host PID, not the kthread's PID in
the reader's own pid_ns.

The SQPOLL kthread is created with CLONE_THREAD and no
CLONE_NEW*, so it lives in the submitter's pid_ns. An
unprivileged user_ns + pid_ns submitter can read fdinfo and
learn the host PID of a kthread whose in-namespace PID is
different.

Reproducer (mainline 7.0, KASAN): unshare CLONE_NEWUSER |
CLONE_NEWPID | CLONE_NEWNS, mount a private /proc, then have a
grandchild that is pid 1 in the new pid_ns open an io_uring
ring with IORING_SETUP_SQPOLL. /proc/self/task lists {1, 2};
the SQPOLL kthread is pid 2. Before: fdinfo prints
SqThread = <host pid>. After: SqThread = 2.

Use task_pid_nr_ns() against the proc inode's pid_ns to compute
sq_pid, instead of reading the stored sq->task_pid (which holds
the init_pid_ns view). pidfd_show_fdinfo() in kernel/pid.c
follows the same pattern.

Signed-off-by: Maoyi Xie <maoyi.xie@ntu.edu.sg>
Link: https://patch.msgid.link/20260510084119.457578-1-maoyi.xie@ntu.edu.sg
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-11 07:44:09 -06:00
Linus Torvalds
8be01e1280 io_uring-7.1-20260508
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Merge tag 'io_uring-7.1-20260508' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux

Pull io_uring fixes from Jens Axboe:

 - Ensure that the absolute timeouts for both the command side and the
   waiting side honor the callers time namespace

 - Ensure tracked NAPI entries are cleared at unregistration time, as
   the NAPI polling loop checks the list state rather than the general
   NAPI state. This can lead to NAPI polling even after unregistration
   has been done. If unregistered, all NAPI polling should be disabled

 - Fix for eventfd recursive invocation handling

* tag 'io_uring-7.1-20260508' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
  io_uring/wait: honour caller's time namespace for IORING_ENTER_ABS_TIMER
  io_uring/timeout: honour caller's time namespace for IORING_TIMEOUT_ABS
  io_uring/eventfd: reset deferred signal state
  io_uring/napi: clear tracked NAPI entries on unregister
2026-05-08 13:12:48 -07:00
Maoyi Xie
45d2b37a37 io_uring/wait: honour caller's time namespace for IORING_ENTER_ABS_TIMER
io_uring_enter() with IORING_ENTER_ABS_TIMER takes an absolute
timespec from the caller via ext_arg->ts. It arms an ABS mode
hrtimer in __io_cqring_wait_schedule(). The conversion path in
io_uring/wait.c parses ext_arg->ts inline rather than going
through io_parse_user_time(). It therefore does not pick up the
time namespace conversion added by the previous patch.

Apply timens_ktime_to_host() to the parsed time on the
IORING_ENTER_ABS_TIMER branch. This mirrors the IORING_TIMEOUT_ABS
fix in io_parse_user_time(). Use ctx->clockid as the clock id.
ctx->clockid is set either at ring creation or via
IORING_REGISTER_CLOCK.

timens_ktime_to_host() is a no-op for clocks not affected by time
namespaces. It is also a no-op for callers in the initial time
namespace. The fast path is unchanged.

Reproducer: in unshare --user --time, with a -10s monotonic
offset, call io_uring_enter with min_complete=1,
IORING_ENTER_ABS_TIMER, and ts = now + 1s. The call returns
-ETIME after <1ms instead of after the expected ~1s.

Suggested-by: Pavel Begunkov <asml.silence@gmail.com>
Suggested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Maoyi Xie <maoyi.xie@ntu.edu.sg>
Link: https://patch.msgid.link/20260504153755.1293932-3-maoyi.xie@ntu.edu.sg
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-06 04:58:56 -06:00
Maoyi Xie
9cc6bac1be io_uring/timeout: honour caller's time namespace for IORING_TIMEOUT_ABS
io_uring's IORING_OP_TIMEOUT and IORING_OP_LINK_TIMEOUT accept a
timespec from the caller via io_parse_user_time(). With
IORING_TIMEOUT_ABS, the timestamp is an absolute deadline on the
selected clock. The clock is CLOCK_MONOTONIC by default.
CLOCK_BOOTTIME and CLOCK_REALTIME are also selectable.

A submitter inside a CLONE_NEWTIME time namespace observes
CLOCK_MONOTONIC and CLOCK_BOOTTIME shifted by the namespace's
offsets relative to the host. Every other ABS timer interface in
the kernel converts the caller's absolute time to host view via
timens_ktime_to_host() before arming an hrtimer:

  kernel/time/posix-timers.c    -- timer_settime(TIMER_ABSTIME)
  kernel/time/posix-stubs.c     -- clock_nanosleep(TIMER_ABSTIME)
  kernel/time/alarmtimer.c      -- alarm_timer_nsleep(TIMER_ABSTIME)
  fs/timerfd.c                  -- timerfd_settime(TFD_TIMER_ABSTIME)

io_parse_user_time() does not. As a result, an absolute timeout
submitted from within a time namespace is interpreted in host
view. That is generally a different point in time. It may already
be in the past, causing the timer to fire immediately, or far in
the future, causing the timer not to fire when expected.

Reproducer: in unshare --user --time, with a -10s monotonic
offset, submit IORING_OP_TIMEOUT with IORING_TIMEOUT_ABS and
deadline = now + 1s. The CQE is delivered after <1ms instead of
the expected ~1s.

Apply timens_ktime_to_host() to the parsed time when
IORING_TIMEOUT_ABS is set. Split the existing clock id resolver
in io_timeout_get_clock() into a flags only helper
io_flags_to_clock(), so io_parse_user_time() can resolve the
clock without a struct io_timeout_data.

timens_ktime_to_host() is a no-op for clocks not affected by time
namespaces, e.g. CLOCK_REALTIME. It is also a no-op for callers
in the initial time namespace. The fast path is unchanged.

SQPOLL is also covered. The SQPOLL kernel thread is created via
create_io_thread() with CLONE_THREAD and no CLONE_NEW* flag.
copy_namespaces() therefore shares the submitter's nsproxy by
reference. Inside the SQPOLL kthread, current->nsproxy->time_ns
is the submitter's time_ns. timens_ktime_to_host() resolves
correctly.

Suggested-by: Pavel Begunkov <asml.silence@gmail.com>
Suggested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Maoyi Xie <maoyi.xie@ntu.edu.sg>
Link: https://patch.msgid.link/20260504153755.1293932-2-maoyi.xie@ntu.edu.sg
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-06 04:58:56 -06:00
Yufan Chen
04fe9aeb4f io_uring/eventfd: reset deferred signal state
Recursive eventfd wakeups must defer io_uring eventfd signaling because
eventfd_signal_mask() rejects reentry from eventfd wakeup handlers. The
io_ev_fd ops bit tracks an outstanding deferred signal so that the same
rcu_head is not queued twice.

That bit is only set today. Once the first deferred callback runs, later
recursive notifications still see the bit set and skip queueing another
deferred signal. This can leave new completions without a matching
eventfd wake after the first recursive deferral.

Clear the pending bit before issuing the deferred signal. If the wakeup
path recurses while the callback runs, a new signal can be queued for
the next RCU grace period while the current callback keeps its reference
until it returns.

Signed-off-by: Yufan Chen <ericterminal@gmail.com>
Fixes: 60b6c075e8 ("io_uring/eventfd: move to more idiomatic RCU free usage")
Link: https://patch.msgid.link/20260503175710.37209-1-yufan.chen@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-03 23:21:40 -06:00
Yufan Chen
b8c2e9e276 io_uring/napi: clear tracked NAPI entries on unregister
IORING_UNREGISTER_NAPI disables NAPI busy polling, but it currently
leaves any previously tracked NAPI IDs on the ring context. The normal
wait path only checks whether the list is empty before entering the busy
poll helper, so an unregistered ring can still observe stale entries and
run an unexpected busy poll pass.

Make unregister switch the context to inactive and free the tracked
entries. Do the same inactive transition while changing the tracking
strategy, and recheck the expected tracking mode under napi_lock before
inserting a newly learned NAPI ID. This prevents a racing poll path from
repopulating the list after unregister or reconfiguration.

Also make the busy poll dispatcher ignore inactive mode explicitly.

Signed-off-by: Yufan Chen <ericterminal@gmail.com>
Fixes: 6bf90bd8c5 ("io_uring/napi: add static napi tracking strategy")
Link: https://patch.msgid.link/20260503175610.35521-1-yufan.chen@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-03 23:21:23 -06:00
Linus Torvalds
9d88bb929a io_uring-7.1-20260430
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Merge tag 'io_uring-7.1-20260430' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux

Pull io_uring fixes from Jens Axboe:

 - Remove dead struct io_buffer_list member

 - Fix for incrementally consumed buffers with recvmsg multishot, which
   requires a minimum value left in a buffer for any receive for the
   headers. If there's still a bit of buffer left but it's smaller than
   that value, then userspace will see a spurious -EFAULT returned in
   the CQE

 - Locking fix for the DEFER_TASKRUN retry list, which otherwise could
   race with fallback cancelations. If the task is exiting with
   task_work left in both the normal and retry list AND the exit cleanup
   races with the task running task work, then entries could either be
   doubly completed or lost

 - Cap NAPI busy poll timeout to something sane, to avoid syzbot running
   into excessive polling and triggering warnings around that

* tag 'io_uring-7.1-20260430' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
  io_uring/tw: serialize ctx->retry_llist with ->uring_lock
  io_uring/napi: cap busy_poll_to 10 msec
  io_uring/kbuf: support min length left for incremental buffers
  io_uring/kbuf: kill dead struct io_buffer_list 'nr_entries' member
2026-05-01 11:01:31 -07:00
Jens Axboe
17666e2d75 io_uring/tw: serialize ctx->retry_llist with ->uring_lock
The DEFER_TASKRUN local task work paths all run under ctx->uring_lock,
which serializes them with each other and with the rest of the ring's
hot paths. io_move_task_work_from_local() is the exception - it's called
from io_ring_exit_work() on a kworker without holding the lock and from
the iopoll cancelation side right after dropping it.

->work_llist is fine with this, as it's only ever updated via the
expected paths. But the ->retry_llist is updated while runing, and hence
it could potentially race between normal task_work running and the
task-has-exited shutdown path.

Simply grab ->uring_lock while moving the local work to the fallback
list for exit purposes, which nicely serializes it across both the
normal additions and the exit prune path.

Cc: stable@vger.kernel.org
Fixes: f46b9cdb22 ("io_uring: limit local tw done")
Reported-by: Robert Femmer <robert.femmer@x41-dsec.de>
Reported-by: Christian Reitter <invd@inhq.net>
Reported-by: Michael Rodler <michael.rodler@x41-dsec.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-30 06:57:20 -06:00
Jakub Kicinski
735a309b4b net: add net_iov_init() and use it to initialize ->page_type
Commit db359fccf2 ("mm: introduce a new page type for page pool in
page type") added a page_type field to struct net_iov at the same
offset as struct page::page_type, so that page_pool_set_pp_info() can
call __SetPageNetpp() uniformly on both pages and net_iovs.

The page-type API requires the field to hold the UINT_MAX "no type"
sentinel before a type can be set; for real struct page that invariant
is established by the page allocator on free. struct net_iov is not
allocated through the page allocator, so the field is left as zero
(io_uring zcrx, which uses __GFP_ZERO) or as slab garbage (devmem,
which uses kvmalloc_objs() without zeroing). When the page pool then
calls page_pool_set_pp_info() on a freshly-bound niov,
__SetPageNetpp()'s VM_BUG_ON_PAGE(page->page_type != UINT_MAX) fires
and the kernel BUGs. Triggered in selftests by io_uring zcrx setup
through the fbnic queue restart path:

 kernel BUG at ./include/linux/page-flags.h:1062!
 RIP: 0010:page_pool_set_pp_info (./include/linux/page-flags.h:1062
                                  net/core/page_pool.c:716)
 Call Trace:
  <TASK>
  net_mp_niov_set_page_pool (net/core/page_pool.c:1360)
  io_pp_zc_alloc_netmems (io_uring/zcrx.c:1089 io_uring/zcrx.c:1110)
  fbnic_fill_bdq (./include/net/page_pool/helpers.h:160
                  drivers/net/ethernet/meta/fbnic/fbnic_txrx.c:906)
  __fbnic_nv_restart (drivers/net/ethernet/meta/fbnic/fbnic_txrx.c:2470
                      drivers/net/ethernet/meta/fbnic/fbnic_txrx.c:2874)
  fbnic_queue_start (drivers/net/ethernet/meta/fbnic/fbnic_txrx.c:2903)
  netdev_rx_queue_reconfig (net/core/netdev_rx_queue.c:137)
  __netif_mp_open_rxq (net/core/netdev_rx_queue.c:234)
  io_register_zcrx (io_uring/zcrx.c:818 io_uring/zcrx.c:903)
  __io_uring_register (io_uring/register.c:931)
  __do_sys_io_uring_register (io_uring/register.c:1029)
  do_syscall_64 (arch/x86/entry/syscall_64.c:63
                 arch/x86/entry/syscall_64.c:94)
  </TASK>

The same path is reachable through devmem dmabuf binding via
netdev_nl_bind_rx_doit() -> net_devmem_bind_dmabuf_to_queue().

Add a net_iov_init() helper that stamps ->owner, ->type and the
->page_type sentinel, and use it from both the devmem and io_uring
zcrx niov init loops.

Fixes: db359fccf2 ("mm: introduce a new page type for page pool in page type")
Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Acked-by: Byungchul Park <byungchul@sk.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/20260428025320.853452-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-29 16:40:08 -07:00
Jens Axboe
df8599ee18 io_uring/napi: cap busy_poll_to 10 msec
Currently there's no cap on the maximum amount of time that napi is
allowed to poll if no events are found, which can lead to kernel
complaints on a task being stuck as there's no conditional rescheduling
done within that loop.

Just cap it to 10 msec in total, that's already way above any kind of
sane value that will reap any benefits, yet low enough that it's
nowhere near being able to trigger preemption complaints.

Fixes: 8d0c12a80c ("io-uring: add napi busy poll support")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-28 16:09:02 -06:00
Martin Michaelis
7deba791ad io_uring/kbuf: support min length left for incremental buffers
Incrementally consumed buffer rings are generally fully consumed, but
it's quite possible that the application has a minimum size it needs to
meet to avoid truncation. Currently that minimum limit is 1 byte, but
this should be a setting that is the hands of the application. For
recvmsg multishot, a prime use case for incrementally consumed buffers,
the application may get spurious -EFAULT returned at the end of an
incrementally consumed buffer, as less space is available than the
headers need.

Grab a u32 field in struct io_uring_buf_reg, which the application can
use to inform the kernel of the minimum size that should be available
in an incrementally consumed buffer. If less than that is available,
the current buffer is fully processed and the next one will be picked.

Cc: stable@vger.kernel.org
Fixes: ae98dbf43d ("io_uring/kbuf: add support for incremental buffer consumption")
Link: https://github.com/axboe/liburing/issues/1433
Signed-off-by: Martin Michaelis <code@mgjm.de>
[axboe: write commit message, change io_buffer_list member name]
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-28 16:08:56 -06:00
Jens Axboe
55ea968389 io_uring/kbuf: kill dead struct io_buffer_list 'nr_entries' member
This is only ever assigned, never used. The only used part is the
calculated mask, which is used for indexing. Kill 'nr_entries'.

Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-28 16:08:44 -06:00
Greg Kroah-Hartman
d0be8884f5 io_uring: take page references for NOMMU pbuf_ring mmaps
Under !CONFIG_MMU, io_uring_get_unmapped_area() returns the kernel
virtual address of the io_mapped_region's backing pages directly;
the user's VMA aliases the kernel allocation. io_uring_mmap() then
just returns 0 -- it takes no page references.

The CONFIG_MMU path uses vm_insert_pages(), which takes a reference on
each inserted page.  Those references are released when the VMA is torn
down (zap_pte_range -> put_page). io_free_region() -> release_pages()
drops the io_uring-side references, but the pages survive until munmap
drops the VMA-side references.

Under NOMMU there are no VMA-side references. io_unregister_pbuf_ring ->
io_put_bl -> io_free_region -> release_pages drops the only references
and the pages return to the buddy allocator while the user's VMA still
has vm_start pointing into them.  The user can then write into whatever
the allocator hands out next.

Mirror the MMU lifetime: take get_page references in io_uring_mmap() and
release them via vm_ops->close.  NOMMU's delete_vma() calls vma_close()
which runs ->close on munmap.

This also incidentally addresses the duplicate-vm_start case: two mmaps
of SQ_RING and CQ_RING resolve to the same ctx->ring_region pointer.
With page refs taken per mmap, the second mmap takes its own refs and
the pages survive until both mmaps are closed.  The nommu rb-tree BUG_ON
on duplicate vm_start is a separate mm/nommu.c concern (it should share
the existing region rather than BUG), but the page lifetime is now
correct.

Cc: Jens Axboe <axboe@kernel.dk>
Reported-by: Anthropic
Assisted-by: gkh_clanker_t1000
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/2026042115-body-attention-d15b@gregkh
[axboe: get rid of region lookup, just iterate pages in vma]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-21 20:14:39 -06:00
Jens Axboe
1967f0b1ca io_uring/poll: ensure EPOLL_ONESHOT is propagated for EPOLL_URING_WAKE
Commit:

aacf2f9f38 ("io_uring: fix req->apoll_events")

fixed an issue where poll->events and req->apoll_events weren't
synchronized, but then when the commit referenced in Fixes got added,
it didn't ensure the same thing.

If we mask in EPOLLONESHOT in the regular EPOLL_URING_WAKE path, then
ensure it's done for both. Including a link to the original report
below, even though it's mostly nonsense. But it includes a reproducer
that does show that IORING_CQE_F_MORE is set in the previous CQE,
while no more CQEs will be generated for this request. Just ignore
anything that pretends this is security related in any way, it's just
the typical AI nonsense.

Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/io-uring/CAM0zi7yQzF3eKncgHo4iVM5yFLAjsiob_ucqyWKs=hyd_GqiMg@mail.gmail.com/
Reported-by: Azizcan Daştan <azizcan.d@mileniumsec.com>
Fixes: 4464853277 ("io_uring: pass in EPOLL_URING_WAKE for eventfd signaling and wakeups")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-21 19:18:34 -06:00
Pavel Begunkov
770594e78c io_uring/zcrx: warn on freelist violations
The freelist is appropriately sized to always be able to take a free
niov, but let's be more defensive and check the invariant with a
warning. That should help to catch any double-free issues.

Suggested-by: Kai Aizen <kai@snailsploit.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/2f3cea363b04649755e3b6bb9ab66485a95936d5.1776760901.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-21 12:19:11 -06:00
Pavel Begunkov
4f02cc4071 io_uring/zcrx: clear RQ headers on init
It might be unexpected to users if the RQ head/tail after a ring
creation are not zeroed, fix that.

Cc: stable@vger.kernel.org
Fixes: 6f377873cb ("io_uring/zcrx: add interface queue and refill queue")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/331f94663c3e8f021ffa3cb770ca2844a07d4855.1776760911.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-21 12:19:11 -06:00
Pavel Begunkov
0fcccfd871 io_uring/zcrx: fix user_struct uaf
io_free_rbuf_ring() usees a struct user_struct, which
io_zcrx_ifq_free() puts it down before destroying the ring.

Cc: stable@vger.kernel.org
Fixes: 5c686456a4 ("io_uring/zcrx: add user_struct and mm_struct to io_zcrx_ifq")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/e560ae00960d27a810522a7efc0e201c82dff351.1776760917.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-21 12:19:11 -06:00
Jens Axboe
45cd95763e io_uring/register: fix ring resizing with mixed/large SQEs/CQEs
The ring resizing only properly handles "normal" sized SQEs or CQEs, if
there are pending entries around a resize. This normally should not be
the case, but the code is supposed to handle this regardless.

For the mixed SQE/CQE cases, the current copying works fine as they
are indexed in the same way. Each half is just copied separately. But
for fixed large SQEs and CQEs, the iteration and copy need to take that
into account.

Cc: stable@kernel.org
Fixes: 79cfe9e59c ("io_uring/register: add IORING_REGISTER_RESIZE_RINGS")
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-21 12:19:08 -06:00
Jens Axboe
7faaa6812a io_uring/futex: ensure partial wakes are appropriately dequeued
If a FUTEX_WAITV vectored operation is only partially woken, we
should call __futex_wake_mark() on the queue to account for that.
If not, then a later wakeup will wake the same entry, rather than
the next one in line.

Fixes: 8f350194d5 ("io_uring: add support for vectored futex waits")
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-21 12:19:06 -06:00
Jens Axboe
7996883455 io_uring/rw: add defensive hardening for negative kbuf lengths
No real bug here, just being a bit defensive in ensuring that whatever
gets passed into io_put_kbuf() is always >= 0 and not some random error
value.

Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-21 12:19:03 -06:00
Jens Axboe
02b8d41c17 io_uring/rsrc: use kvfree() for the imu cache
Currently anything that requires kvmalloc_flex() for allocations will
not get re-cached, and hence the cache freeing path is correct in that
it always uses kfree() to free the allocated memory. But this seems a
bit fragile as it's something that could get mix should that situation
change, so switch io_free_imu() and io_alloc_cache_free() to use kvfree
as the desctructor.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-21 12:19:01 -06:00
Jens Axboe
53262c91f7 io_uring/rsrc: unify nospec indexing for direct descriptors
For file updates, the node reset isn't capping the value via
array_index_nospec() like the other paths do. Ensure it's all sane and
have the update path do the proper capping as well.

Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-21 12:18:54 -06:00
Jens Axboe
8e1f412b5b io_uring: fix spurious fput in registered ring path
Fix an issue with io_uring_ctx_get_file() not gating fput() on whether
or not the file descriptor is a registered/direct one or not.

Fixes: c5e9f6a96b ("io_uring: unify getting ctx from passed in file descriptor")
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-21 12:18:44 -06:00
Jens Axboe
42a702aaed io_uring: fix iowq_limits data race in tctx node addition
__io_uring_add_tctx_node() reads ctx->int_flags and
ctx->iowq_limits[0..1] without holding ctx->uring_lock, while
io_register_iowq_max_workers() writes these same fields under the lock.

Mostly an application problem if you try and make these race, but let's
silence KCSAN by just grabbing the ->uring_lock around the operation.
This is a slow path operation anyway, and ->uring_lock will be grabbed
by submission right after anyway.

Fixes: 2e480058dd ("io-wq: provide a way to limit max number of workers")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-20 14:57:21 -06:00
Jens Axboe
41859843f2 io_uring/tctx: mark io_wq as exiting before error path teardown
syzbot reports that it's hitting the below condition for exiting an
io_wq context:

WARN_ON_ONCE(!test_bit(IO_WQ_BIT_EXIT, &wq->state))

in io_wq_put_and_exit(), which can be triggered with memory allocation
fault injection. Ensure that the io_wq is marked as exiting to silence
this warning trigger.

Reported-by: syzbot+79a4cc863a8db58cd92b@syzkaller.appspotmail.com
Fixes: 7880174e1e ("io_uring/tctx: clean up __io_uring_add_tctx_node() error handling")
Reviewed-by: Clément Léger <cleger@meta.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-20 14:47:37 -06:00
Jens Axboe
ee5417fd02 io_uring/tctx: check for setup tctx->io_wq before teardown
As with the idling code before it, the error exit path should check for
a NULL tctx->io_wq before calling io_wq_put_and_exit().

Fixes: 7880174e1e ("io_uring/tctx: clean up __io_uring_add_tctx_node() error handling")
Reported-by: Dan Carpenter <error27@gmail.com>
Reviewed-by: Clément Léger <cleger@meta.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-20 14:47:29 -06:00
Longxuan Yu
326941b228 io_uring/poll: fix signed comparison in io_poll_get_ownership()
io_poll_get_ownership() uses a signed comparison to check whether
poll_refs has reached the threshold for the slowpath:

    if (unlikely(atomic_read(&req->poll_refs) >= IO_POLL_REF_BIAS))

atomic_read() returns int (signed). When IO_POLL_CANCEL_FLAG
(BIT(31)) is set in poll_refs, the value becomes negative in
signed arithmetic, so the >= 128 comparison always evaluates to
false and the slowpath is never taken.

Fix this by casting the atomic_read() result to unsigned int
before the comparison, so that the cancel flag is treated as a
large positive value and correctly triggers the slowpath.

Fixes: a26a35e901 ("io_uring: make poll refs more robust")
Cc: stable@vger.kernel.org
Reported-by: Yifan Wu <yifanwucs@gmail.com>
Reported-by: Juefei Pu <tomapufckgml@gmail.com>
Co-developed-by: Yuan Tan <yuantan098@gmail.com>
Signed-off-by: Yuan Tan <yuantan098@gmail.com>
Suggested-by: Xin Liu <bird@lzu.edu.cn>
Tested-by: Zhengchuan Liang <zcliangcn@gmail.com>
Signed-off-by: Longxuan Yu <ylong030@ucr.edu>
Signed-off-by: Ren Wei <n05ec@lzu.edu.cn>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/3a3508b08bcd7f1bc3beff848ae6e1d73d355043.1775965597.git.ylong030@ucr.edu
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-15 14:07:47 -06:00
Linus Torvalds
91a4855d6c Networking changes for 7.1.
Core & protocols
 ----------------
 
  - Support HW queue leasing, allowing containers to be granted access
    to HW queues for zero-copy operations and AF_XDP.
 
  - Number of code moves to help the compiler with inlining.
    Avoid output arguments for returning drop reason where possible.
 
  - Rework drop handling within qdiscs to include more metadata
    about the reason and dropping qdisc in the tracepoints.
 
  - Remove the rtnl_lock use from IP Multicast Routing.
 
  - Pack size information into the Rx Flow Steering table pointer
    itself. This allows making the table itself a flat array of u32s,
    thus making the table allocation size a power of two.
 
  - Report TCP delayed ack timer information via socket diag.
 
  - Add ip_local_port_step_width sysctl to allow distributing the randomly
    selected ports more evenly throughout the allowed space.
 
  - Add support for per-route tunsrc in IPv6 segment routing.
 
  - Start work of switching sockopt handling to iov_iter.
 
  - Improve dynamic recvbuf sizing in MPTCP, limit burstiness and avoid
    buffer size drifting up.
 
  - Support MSG_EOR in MPTCP.
 
  - Add stp_mode attribute to the bridge driver for STP mode selection.
    This addresses concerns about call_usermodehelper() usage.
 
  - Remove UDP-Lite support (as announced in 2023).
 
  - Remove support for building IPv6 as a module.
    Remove the now unnecessary function calling indirection.
 
 Cross-tree stuff
 ----------------
 
  - Move Michael MIC code from generic crypto into wireless,
    it's considered insecure but some WiFi networks still need it.
 
 Netfilter
 ---------
 
  - Switch nft_fib_ipv6 module to no longer need temporary dst_entry
    object allocations by using fib6_lookup() + RCU.
    Florian W reports this gets us ~13% higher packet rate.
 
  - Convert IPVS's global __ip_vs_mutex to per-net service_mutex and
    switch the service tables to be per-net. Convert some code that
    walks the service lists to use RCU instead of the service_mutex.
 
  - Add more opinionated input validation to lower security exposure.
 
  - Make IPVS hash tables to be per-netns and resizable.
 
 Wireless
 --------
 
  - Finished assoc frame encryption/EPPKE/802.1X-over-auth.
 
  - Radar detection improvements.
 
  - Add 6 GHz incumbent signal detection APIs.
 
  - Multi-link support for FILS, probe response templates and
    client probing.
 
  - New APIs and mac80211 support for NAN (Neighbor Aware Networking,
    aka Wi-Fi Aware) so less work must be in firmware.
 
 Driver API
 ----------
 
  - Add numerical ID for devlink instances (to avoid having to create
    fake bus/device pairs just to have an ID). Support shared devlink
    instances which span multiple PFs.
 
  - Add standard counters for reporting pause storm events
    (implement in mlx5 and fbnic).
 
  - Add configuration API for completion writeback buffering
    (implement in mana).
 
  - Support driver-initiated change of RSS context sizes.
 
  - Support DPLL monitoring input frequency (implement in zl3073x).
 
  - Support per-port resources in devlink (implement in mlx5).
 
 Misc
 ----
 
  - Expand the YAML spec for Netfilter.
 
 Drivers
 -------
 
  - Software:
    - macvlan: support multicast rx for bridge ports with shared source
      MAC address
    - team: decouple receive and transmit enablement for IEEE 802.3ad
      LACP "independent control"
 
  - Ethernet high-speed NICs:
    - nVidia/Mellanox:
      - support high order pages in zero-copy mode (for payload
        coalescing)
      - support multiple packets in a page (for systems with 64kB pages)
    - Broadcom 25-400GE (bnxt):
      - implement XDP RSS hash metadata extraction
      - add software fallback for UDP GSO, lowering the IOMMU cost
    - Broadcom 800GE (bnge):
      - add link status and configuration handling
      - add various HW and SW statistics
    - Marvell/Cavium:
      - NPC HW block support for cn20k
    - Huawei (hinic3):
      - add mailbox / control queue
      - add rx VLAN offload
      - add driver info and link management
 
  - Ethernet NICs:
    - Marvell/Aquantia:
      - support reading SFP module info on some AQC100 cards
    - Realtek PCI (r8169):
      - add support for RTL8125cp
    - Realtek USB (r8152):
      - support for the RTL8157 5Gbit chip
      - add 2500baseT EEE status/configuration support
 
  - Ethernet NICs embedded and off-the-shelf IP:
    - Synopsys (stmmac):
      - cleanup and reorganize SerDes handling and PCS support
      - cleanup descriptor handling and per-platform data
      - cleanup and consolidate MDIO defines and handling
      - shrink driver memory use for internal structures
      - improve Tx IRQ coalescing
      - improve TCP segmentation handling
      - add support for Spacemit K3
    - Cadence (macb):
      - support PHYs that have inband autoneg disabled with GEM
      - support IEEE 802.3az EEE
      - rework usrio capabilities and handling
    - AMD (xgbe):
      - improve power management for S0i3
      - improve TX resilience for link-down handling
 
  - Virtual:
    - Google cloud vNIC:
      - support larger ring sizes in DQO-QPL mode
      - improve HW-GRO handling
      - support UDP GSO for DQO format
    - PCIe NTB:
      - support queue count configuration
 
  - Ethernet PHYs:
    - automatically disable PHY autonomous EEE if MAC is in charge
    - Broadcom:
      - add BCM84891/BCM84892 support
    - Micrel:
      - support for LAN9645X internal PHY
    - Realtek:
      - add RTL8224 pair order support
      - support PHY LEDs on RTL8211F-VD
      - support spread spectrum clocking (SSC)
    - Maxlinear:
      - add PHY-level statistics via ethtool
 
  - Ethernet switches:
    - Maxlinear (mxl862xx):
      - support for bridge offloading
      - support for VLANs
      - support driver statistics
 
  - Bluetooth:
    - large number of fixes and new device IDs
    - Mediatek:
      - support MT6639 (MT7927)
      - support MT7902 SDIO
 
  - WiFi:
    - Intel (iwlwifi):
      - UNII-9 and continuing UHR work
    - MediaTek (mt76):
      - mt7996/mt7925 MLO fixes/improvements
      - mt7996 NPU support (HW eth/wifi traffic offload)
    - Qualcomm (ath12k):
      - monitor mode support on IPQ5332
      - basic hwmon temperature reporting
      - support IPQ5424
    - Realtek:
      - add USB RX aggregation to improve performance
      - add USB TX flow control by tracking in-flight URBs
 
  - Cellular:
    - IPA v5.2 support
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-next-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Jakub Kicinski:
 "Core & protocols:

   - Support HW queue leasing, allowing containers to be granted access
     to HW queues for zero-copy operations and AF_XDP

   - Number of code moves to help the compiler with inlining. Avoid
     output arguments for returning drop reason where possible

   - Rework drop handling within qdiscs to include more metadata about
     the reason and dropping qdisc in the tracepoints

   - Remove the rtnl_lock use from IP Multicast Routing

   - Pack size information into the Rx Flow Steering table pointer
     itself. This allows making the table itself a flat array of u32s,
     thus making the table allocation size a power of two

   - Report TCP delayed ack timer information via socket diag

   - Add ip_local_port_step_width sysctl to allow distributing the
     randomly selected ports more evenly throughout the allowed space

   - Add support for per-route tunsrc in IPv6 segment routing

   - Start work of switching sockopt handling to iov_iter

   - Improve dynamic recvbuf sizing in MPTCP, limit burstiness and avoid
     buffer size drifting up

   - Support MSG_EOR in MPTCP

   - Add stp_mode attribute to the bridge driver for STP mode selection.
     This addresses concerns about call_usermodehelper() usage

   - Remove UDP-Lite support (as announced in 2023)

   - Remove support for building IPv6 as a module. Remove the now
     unnecessary function calling indirection

  Cross-tree stuff:

   - Move Michael MIC code from generic crypto into wireless, it's
     considered insecure but some WiFi networks still need it

  Netfilter:

   - Switch nft_fib_ipv6 module to no longer need temporary dst_entry
     object allocations by using fib6_lookup() + RCU.

     Florian W reports this gets us ~13% higher packet rate

   - Convert IPVS's global __ip_vs_mutex to per-net service_mutex and
     switch the service tables to be per-net. Convert some code that
     walks the service lists to use RCU instead of the service_mutex

   - Add more opinionated input validation to lower security exposure

   - Make IPVS hash tables to be per-netns and resizable

  Wireless:

   - Finished assoc frame encryption/EPPKE/802.1X-over-auth

   - Radar detection improvements

   - Add 6 GHz incumbent signal detection APIs

   - Multi-link support for FILS, probe response templates and client
     probing

   - New APIs and mac80211 support for NAN (Neighbor Aware Networking,
     aka Wi-Fi Aware) so less work must be in firmware

  Driver API:

   - Add numerical ID for devlink instances (to avoid having to create
     fake bus/device pairs just to have an ID). Support shared devlink
     instances which span multiple PFs

   - Add standard counters for reporting pause storm events (implement
     in mlx5 and fbnic)

   - Add configuration API for completion writeback buffering (implement
     in mana)

   - Support driver-initiated change of RSS context sizes

   - Support DPLL monitoring input frequency (implement in zl3073x)

   - Support per-port resources in devlink (implement in mlx5)

  Misc:

   - Expand the YAML spec for Netfilter

  Drivers

   - Software:
      - macvlan: support multicast rx for bridge ports with shared
        source MAC address
      - team: decouple receive and transmit enablement for IEEE 802.3ad
        LACP "independent control"

   - Ethernet high-speed NICs:
      - nVidia/Mellanox:
         - support high order pages in zero-copy mode (for payload
           coalescing)
         - support multiple packets in a page (for systems with 64kB
           pages)
      - Broadcom 25-400GE (bnxt):
         - implement XDP RSS hash metadata extraction
         - add software fallback for UDP GSO, lowering the IOMMU cost
      - Broadcom 800GE (bnge):
         - add link status and configuration handling
         - add various HW and SW statistics
      - Marvell/Cavium:
         - NPC HW block support for cn20k
      - Huawei (hinic3):
         - add mailbox / control queue
         - add rx VLAN offload
         - add driver info and link management

   - Ethernet NICs:
      - Marvell/Aquantia:
         - support reading SFP module info on some AQC100 cards
      - Realtek PCI (r8169):
         - add support for RTL8125cp
      - Realtek USB (r8152):
         - support for the RTL8157 5Gbit chip
         - add 2500baseT EEE status/configuration support

   - Ethernet NICs embedded and off-the-shelf IP:
      - Synopsys (stmmac):
         - cleanup and reorganize SerDes handling and PCS support
         - cleanup descriptor handling and per-platform data
         - cleanup and consolidate MDIO defines and handling
         - shrink driver memory use for internal structures
         - improve Tx IRQ coalescing
         - improve TCP segmentation handling
         - add support for Spacemit K3
      - Cadence (macb):
         - support PHYs that have inband autoneg disabled with GEM
         - support IEEE 802.3az EEE
         - rework usrio capabilities and handling
      - AMD (xgbe):
         - improve power management for S0i3
         - improve TX resilience for link-down handling

   - Virtual:
      - Google cloud vNIC:
         - support larger ring sizes in DQO-QPL mode
         - improve HW-GRO handling
         - support UDP GSO for DQO format
      - PCIe NTB:
         - support queue count configuration

   - Ethernet PHYs:
      - automatically disable PHY autonomous EEE if MAC is in charge
      - Broadcom:
         - add BCM84891/BCM84892 support
      - Micrel:
         - support for LAN9645X internal PHY
      - Realtek:
         - add RTL8224 pair order support
         - support PHY LEDs on RTL8211F-VD
         - support spread spectrum clocking (SSC)
      - Maxlinear:
         - add PHY-level statistics via ethtool

   - Ethernet switches:
      - Maxlinear (mxl862xx):
         - support for bridge offloading
         - support for VLANs
         - support driver statistics

   - Bluetooth:
      - large number of fixes and new device IDs
      - Mediatek:
         - support MT6639 (MT7927)
         - support MT7902 SDIO

   - WiFi:
      - Intel (iwlwifi):
         - UNII-9 and continuing UHR work
      - MediaTek (mt76):
         - mt7996/mt7925 MLO fixes/improvements
         - mt7996 NPU support (HW eth/wifi traffic offload)
      - Qualcomm (ath12k):
         - monitor mode support on IPQ5332
         - basic hwmon temperature reporting
         - support IPQ5424
      - Realtek:
         - add USB RX aggregation to improve performance
         - add USB TX flow control by tracking in-flight URBs

   - Cellular:
      - IPA v5.2 support"

* tag 'net-next-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1561 commits)
  net: pse-pd: fix kernel-doc function name for pse_control_find_by_id()
  wireguard: device: use exit_rtnl callback instead of manual rtnl_lock in pre_exit
  wireguard: allowedips: remove redundant space
  tools: ynl: add sample for wireguard
  wireguard: allowedips: Use kfree_rcu() instead of call_rcu()
  MAINTAINERS: Add netkit selftest files
  selftests/net: Add additional test coverage in nk_qlease
  selftests/net: Split netdevsim tests from HW tests in nk_qlease
  tools/ynl: Make YnlFamily closeable as a context manager
  net: airoha: Add missing PPE configurations in airoha_ppe_hw_init()
  net: airoha: Fix VIP configuration for AN7583 SoC
  net: caif: clear client service pointer on teardown
  net: strparser: fix skb_head leak in strp_abort_strp()
  net: usb: cdc-phonet: fix skb frags[] overflow in rx_complete()
  selftests/bpf: add test for xdp_master_redirect with bond not up
  net, bpf: fix null-ptr-deref in xdp_master_redirect() for down master
  net: airoha: Remove PCE_MC_EN_MASK bit in REG_FE_PCE_CFG configuration
  sctp: disable BH before calling udp_tunnel_xmit_skb()
  sctp: fix missing encap_port propagation for GSO fragments
  net: airoha: Rely on net_device pointer in ETS callbacks
  ...
2026-04-14 18:36:10 -07:00
Linus Torvalds
23acda7c22 for-7.1/io_uring-20260411
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Merge tag 'for-7.1/io_uring-20260411' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux

Pull io_uring updates from Jens Axboe:

 - Add a callback driven main loop for io_uring, and BPF struct_ops
   on top to allow implementing custom event loop logic

 - Decouple IOPOLL from being a ring-wide all-or-nothing setting,
   allowing IOPOLL use cases to also issue certain white listed
   non-polled opcodes

 - Timeout improvements. Migrate internal timeout storage from
   timespec64 to ktime_t for simpler arithmetic and avoid copying of
   timespec data

 - Zero-copy receive (zcrx) updates:

      - Add a device-less mode (ZCRX_REG_NODEV) for testing and
        experimentation where data flows through the copy fallback path

      - Fix two-step unregistration regression, DMA length calculations,
        xarray mark usage, and a potential 32-bit overflow in id
        shifting

      - Refactoring toward multi-area support: dedicated refill queue
        struct, consolidated DMA syncing, netmem array refilling format,
        and guard-based locking

 - Zero-copy transmit (zctx) cleanup:

      - Unify io_send_zc() and io_sendmsg_zc() into a single function

      - Add vectorized registered buffer send for IORING_OP_SEND_ZC

      - Add separate notification user_data via sqe->addr3 so
        notification and completion CQEs can be distinguished without
        extra reference counting

 - Switch struct io_ring_ctx internal bitfields to explicit flag bits
   with atomic-safe accessors, and annotate the known harmless races on
   those flags

 - Various optimizations caching ctx and other request fields in local
   variables to avoid repeated loads, and cleanups for tctx setup, ring
   fd registration, and read path early returns

* tag 'for-7.1/io_uring-20260411' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (58 commits)
  io_uring: unify getting ctx from passed in file descriptor
  io_uring/register: don't get a reference to the registered ring fd
  io_uring/tctx: clean up __io_uring_add_tctx_node() error handling
  io_uring/tctx: have io_uring_alloc_task_context() return tctx
  io_uring/timeout: use 'ctx' consistently
  io_uring/rw: clean up __io_read() obsolete comment and early returns
  io_uring/zcrx: use correct mmap off constants
  io_uring/zcrx: use dma_len for chunk size calculation
  io_uring/zcrx: don't clear not allocated niovs
  io_uring/zcrx: don't use mark0 for allocating xarray
  io_uring: cast id to u64 before shifting in io_allocate_rbuf_ring()
  io_uring/zcrx: reject REG_NODEV with large rx_buf_size
  io_uring/cancel: validate opcode for IORING_ASYNC_CANCEL_OP
  io_uring/rsrc: use io_cache_free() to free node
  io_uring/zcrx: rename zcrx [un]register functions
  io_uring/zcrx: check ctrl op payload struct sizes
  io_uring/zcrx: cache fallback availability in zcrx ctx
  io_uring/zcrx: warn on a repeated area append
  io_uring/zcrx: consolidate dma syncing
  io_uring/zcrx: netmem array as refiling format
  ...
2026-04-13 16:22:30 -07:00
Linus Torvalds
ef3da345cc vfs-7.1-rc1.misc
Please consider pulling these changes from the signed vfs-7.1-rc1.misc tag.
 
 Thanks!
 Christian
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Merge tag 'vfs-7.1-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull misc vfs updates from Christian Brauner:
 "Features:
   - coredump: add tracepoint for coredump events
   - fs: hide file and bfile caches behind runtime const machinery

  Fixes:
   - fix architecture-specific compat_ftruncate64 implementations
   - dcache: Limit the minimal number of bucket to two
   - fs/omfs: reject s_sys_blocksize smaller than OMFS_DIR_START
   - fs/mbcache: cancel shrink work before destroying the cache
   - dcache: permit dynamic_dname()s up to NAME_MAX

  Cleanups:
   - remove or unexport unused fs_context infrastructure
   - trivial ->setattr cleanups
   - selftests/filesystems: Assume that TIOCGPTPEER is defined
   - writeback: fix kernel-doc function name mismatch for wb_put_many()
   - autofs: replace manual symlink buffer allocation in autofs_dir_symlink
   - init/initramfs.c: trivial fix: FSM -> Finite-state machine
   - fs: remove stale and duplicate forward declarations
   - readdir: Introduce dirent_size()
   - fs: Replace user_access_{begin/end} by scoped user access
   - kernel: acct: fix duplicate word in comment
   - fs: write a better comment in step_into() concerning .mnt assignment
   - fs: attr: fix comment formatting and spelling issues"

* tag 'vfs-7.1-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (28 commits)
  dcache: permit dynamic_dname()s up to NAME_MAX
  fs: attr: fix comment formatting and spelling issues
  fs: hide file and bfile caches behind runtime const machinery
  fs: write a better comment in step_into() concerning .mnt assignment
  proc: rename proc_notify_change to proc_setattr
  proc: rename proc_setattr to proc_nochmod_setattr
  affs: rename affs_notify_change to affs_setattr
  adfs: rename adfs_notify_change to adfs_setattr
  hfs: update comments on hfs_inode_setattr
  kernel: acct: fix duplicate word in comment
  fs: Replace user_access_{begin/end} by scoped user access
  readdir: Introduce dirent_size()
  coredump: add tracepoint for coredump events
  fs: remove do_sys_truncate
  fs: pass on FTRUNCATE_* flags to do_truncate
  fs: fix archiecture-specific compat_ftruncate64
  fs: remove stale and duplicate forward declarations
  init/initramfs.c: trivial fix: FSM -> Finite-state machine
  autofs: replace manual symlink buffer allocation in autofs_dir_symlink
  fs/mbcache: cancel shrink work before destroying the cache
  ...
2026-04-13 14:20:11 -07:00
Jakub Kicinski
1508922588 Merge branch 'netkit-support-for-io_uring-zero-copy-and-af_xdp'
Daniel Borkmann says:

====================
netkit: Support for io_uring zero-copy and AF_XDP

Containers use virtual netdevs to route traffic from a physical netdev
in the host namespace. They do not have access to the physical netdev
in the host and thus can't use memory providers or AF_XDP that require
reconfiguring/restarting queues in the physical netdev.

This patchset adds the concept of queue leasing to virtual netdevs that
allow containers to use memory providers and AF_XDP at native speed.
Leased queues are bound to a real queue in a physical netdev and act
as a proxy.

Memory providers and AF_XDP operations take an ifindex and queue id,
so containers would pass in an ifindex for a virtual netdev and a queue
id of a leased queue, which then gets proxied to the underlying real
queue.

We have implemented support for this concept in netkit and tested the
latter against Nvidia ConnectX-6 (mlx5) as well as Broadcom BCM957504
(bnxt_en) 100G NICs. For more details see the individual patches.
====================

Link: https://patch.msgid.link/20260402231031.447597-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-09 18:24:35 -07:00
David Wei
222b5566a0 net: Proxy netdev_queue_get_dma_dev for leased queues
Extend netdev_queue_get_dma_dev to return the physical device of the
real rxq for DMA in case the queue was leased. This allows memory
providers like io_uring zero-copy or devmem to bind to the physically
leased rxq via virtual devices such as netkit.

Signed-off-by: David Wei <dw@davidwei.uk>
Co-developed-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20260402231031.447597-8-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-09 18:21:46 -07:00
Daniel Borkmann
1e91c98bc9 net: Slightly simplify net_mp_{open,close}_rxq
net_mp_open_rxq is currently not used in the tree as all callers are
using __net_mp_open_rxq directly, and net_mp_close_rxq is only used
once while all other locations use __net_mp_close_rxq.

Consolidate into a single API, netif_mp_{open,close}_rxq, using the
netif_ prefix to indicate that the caller is responsible for locking.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Co-developed-by: David Wei <dw@davidwei.uk>
Signed-off-by: David Wei <dw@davidwei.uk>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20260402231031.447597-6-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-09 18:21:46 -07:00
Jens Axboe
c5e9f6a96b io_uring: unify getting ctx from passed in file descriptor
io_uring_enter() and io_uring_register() end up having duplicated code
for getting a ctx from a passed in file descriptor, for either a
registered ring descriptor or a normal file descriptor. Move the
io_uring_register_get_file() into io_uring.c and name it a bit more
generically, and use it from both callsites rather than have that logic
and handling duplicated.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-08 13:21:35 -06:00
Jens Axboe
b4d893d636 io_uring/register: don't get a reference to the registered ring fd
This isn't necessary and was only done because the register path isn't a
hot path and hence the extra ref/put doesn't matter, and to have the
exit path be able to unconditionally put whatever file was gotten
regardless of the type.

In preparation for sharing this code with the main io_uring_enter(2)
syscall, drop the reference and have the caller conditionally put the
file if it was a normal file descriptor.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-08 13:21:35 -06:00
Jens Axboe
7880174e1e io_uring/tctx: clean up __io_uring_add_tctx_node() error handling
Refactor __io_uring_add_tctx_node() so that on error it never leaves
current->io_uring pointing at a half-setup tctx. This moves the
assignment of current->io_uring to the end of the function post any
failure points.

Separate out the node installation into io_tctx_install_node() to
further clean this up.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-08 13:21:34 -06:00
Jens Axboe
2c453a4281 io_uring/tctx: have io_uring_alloc_task_context() return tctx
Instead of having io_uring_alloc_task_context() return an int and
assign tsk->io_uring, just have it return the task context directly.
This enables cleaner error handling in callers, which may have
failure points post calling io_uring_alloc_task_context().

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-08 13:21:30 -06:00
Linus Torvalds
e41255ce7a io_uring-7.0-20260403
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Merge tag 'io_uring-7.0-20260403' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux

Pull io_uring fixes from Jens Axboe:

 - A previous fix in this release covered the case of the rings being
   RCU protected during resize, but it missed a few spots. This covers
   the rest

 - Fix the cBPF filters when COW'ed, introduced in this merge window

 - Fix for an attempt to import a zero sized buffer

 - Fix for a missing clamp in importing bundle buffers

* tag 'io_uring-7.0-20260403' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
  io_uring/bpf_filters: retain COW'ed settings on parse failures
  io_uring: protect remaining lockless ctx->rings accesses with RCU
  io_uring/rsrc: reject zero-length fixed buffer import
  io_uring/net: fix slab-out-of-bounds read in io_bundle_nbufs()
2026-04-03 11:58:04 -07:00
Yang Xiuwei
f847bf6d29 io_uring/timeout: use 'ctx' consistently
There's already a local ctx variable, yet cq_timeouts accounting uses
req->ctx. Use ctx consistently.

Signed-off-by: Yang Xiuwei <yangxiuwei@kylinos.cn>
Link: https://patch.msgid.link/20260402014952.260414-1-yangxiuwei@kylinos.cn
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-02 07:08:40 -06:00
Joanne Koong
c7f3aaf3e8 io_uring/rw: clean up __io_read() obsolete comment and early returns
After commit a9165b83c1 ("io_uring/rw: always setup io_async_rw for
read/write requests") which moved the iovec allocation into the prep
path and stores it in req->async_data where it now gets freed as part of
the request lifecycle, this comment is now outdated.

Remove it and clean up the goto as well.

Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Link: https://patch.msgid.link/20260401173511.4052303-1-joannelkoong@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-02 06:55:50 -06:00
Pavel Begunkov
4c6f93951b io_uring/zcrx: use correct mmap off constants
zcrx was using IORING_OFF_PBUF_SHIFT during first iterations, but there
is now a separate constant it should use. Both are 16 so it doesn't
change anything, but improve it for the future.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/fe16ebe9ba4048a7e12f9b3b50880bd175b1ce03.1774780198.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-02 06:55:48 -06:00
Pavel Begunkov
7120b87bed io_uring/zcrx: use dma_len for chunk size calculation
Buffers are now dma-mapped earlier and we can sg_dma_len(), otherwise,
since it's walking with for_each_sgtable_dma_sg(), it might wrongfully
reject some configurations. As a bonus, it'd now be able to use larger
chunks if dma addresses are coalesced e.g by iommu.

Fixes: 8c0cab0b7bf7 ("io_uring/zcrx: always dma map in advance")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/03b219af3f6cfdd1cf64679b8bab7461e47cc123.1774780198.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-02 06:55:47 -06:00
Pavel Begunkov
52dcd1776b io_uring/zcrx: don't clear not allocated niovs
Now that area->is_mapped is set earlier before niovs array is allocated,
io_zcrx_free_area -> io_zcrx_unmap_area in an error path can try to
clear dma addresses for unallocated niovs, fix it.

Fixes: 8c0cab0b7bf7 ("io_uring/zcrx: always dma map in advance")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/cbcb7749b5a001ecd4d1c303515ce9403215640c.1774780198.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-02 06:55:36 -06:00
Pavel Begunkov
8ae2837d5a io_uring/zcrx: don't use mark0 for allocating xarray
XA_MARK_0 is not compatible with xarray allocating entries, use
XA_MARK_1.

Fixes: fda90d43f4fac ("io_uring/zcrx: return back two step unregistration")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/f232cfd3c466047d333b474dd2bddd246b6ebb82.1774780198.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-01 10:21:13 -06:00
Anas Iqbal
77d8c8d0f1 io_uring: cast id to u64 before shifting in io_allocate_rbuf_ring()
Smatch warns:
io_uring/zcrx.c:393 io_allocate_rbuf_ring() warn: should 'id << 16' be a 64 bit type?

The expression 'id << IORING_OFF_PBUF_SHIFT' is evaluated using 32-bit
arithmetic because id is a u32. This may overflow before being promoted
to the 64-bit mmap_offset.

Cast id to u64 before shifting to ensure the shift is performed in
64-bit arithmetic.

Signed-off-by: Anas Iqbal <mohd.abd.6602@gmail.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/52400e1b343691416bef3ed3ae287fb1a88d407f.1774780198.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-01 10:21:13 -06:00
Pavel Begunkov
a9d008489f io_uring/zcrx: reject REG_NODEV with large rx_buf_size
The copy fallback path doesn't care about the actual niov size and only
uses first PAGE_SIZE bytes, and any additional space will be wasted.
Since ZCRX_REG_NODEV solely relies on the copy path, it doesn't make
sense to support non-standard rx_buf_len. Reject it for now, and
re-enable once improved.

Fixes: c11728021d5cd ("io_uring/zcrx: implement device-less mode for zcrx")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/3e7652d9c27f8ac5d2b141e3af47971f2771fb05.1774780198.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-01 10:21:13 -06:00
Amir Mohammad Jahangirzad
85a58309c0 io_uring/cancel: validate opcode for IORING_ASYNC_CANCEL_OP
io_async_cancel_prep() reads the opcode selector from sqe->len and
stores it in cancel->opcode, which is an 8-bit field. Since sqe->len
is a 32-bit value, values larger than U8_MAX are implicitly truncated.

This can cause unintended opcode matches when the truncated value
corresponds to a valid io_uring opcode. For example, submitting a value
such as 0x10b will be truncated to 0x0b (IORING_OP_TIMEOUT), allowing a
cancel request to match operations it did not intend to target.
Validate the opcode value before assigning it to the 8-bit field and
reject values outside the valid io_uring opcode range.

Signed-off-by: Amir Mohammad Jahangirzad <a.jahangirzad@gmail.com>
Link: https://patch.msgid.link/20260331232113.615972-1-a.jahangirzad@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-01 10:21:13 -06:00
Jackie Liu
19a8cc6cda io_uring/rsrc: use io_cache_free() to free node
Replace kfree(node) with io_cache_free() in io_buffer_register_bvec()
to match all other error paths that free nodes allocated via
io_rsrc_node_alloc(). The node is allocated through io_cache_alloc()
internally, so it should be returned to the cache via io_cache_free()
for proper object reuse.

Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
Link: https://patch.msgid.link/20260331104509.7055-1-liu.yun@linux.dev
[axboe: remove fixes tag, it's not a fix, it's a cleanup]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-01 10:21:13 -06:00
Pavel Begunkov
7c713dd007 io_uring/zcrx: rename zcrx [un]register functions
Drop "ifqs" from function names, as it refers to an interface queue and
there might be none once a device-less mode is introduced.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/657874acd117ec30fa6f45d9d844471c753b5a0f.1774261953.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-01 10:21:13 -06:00
Pavel Begunkov
de6ed1b323 io_uring/zcrx: check ctrl op payload struct sizes
Add a build check that ctrl payloads are of the same size and don't grow
struct zcrx_ctrl.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/af66caf9776d18e9ff880ab828eb159a6a03caf5.1774261953.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-01 10:21:13 -06:00
Pavel Begunkov
5c727ce042 io_uring/zcrx: cache fallback availability in zcrx ctx
Store a flag in struct io_zcrx_ifq telling if the backing memory is
normal page or dmabuf based. It was looking it up from the area, however
it logically allocates from the zcrx ctx and not a particular area, and
once we add more than one area it'll become a mess.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/65e75408a7758fe7e60fae89b7a8d5ae4857f515.1774261953.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-01 10:21:13 -06:00
Pavel Begunkov
f0b92207a0 io_uring/zcrx: warn on a repeated area append
We only support a single area, no path should be able to call
io_zcrx_append_area() twice. Warn if that happens instead of just
returning an error.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/28eb67fb8c48445584d7c247a36e1ad8800f0c8b.1774261953.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-01 10:21:13 -06:00
Pavel Begunkov
61cfadaae6 io_uring/zcrx: consolidate dma syncing
Split refilling into two steps, first allocate niovs, and then do DMA
sync for them. This way dma synchronisation code can be better
optimised. E.g. we don't need to call dma_dev_need_sync() for each every
niov, and maybe we can coalesce sync for adjacent netmems in the future
as well.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/19f2d50baa62ff2e0c6cd56dd7c394cab728c567.1774261953.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-01 10:21:12 -06:00
Pavel Begunkov
c0989138c0 io_uring/zcrx: netmem array as refiling format
Instead of peeking into page pool allocation cache directly or via
net_mp_netmem_place_in_cache(), pass a netmem array around. It's a
better intermediate format, e.g. you can have it on stack and reuse the
refilling code and decouples it from page pools a bit more.

It still points into the page pool directly, there will be no additional
copies. As the next step, we can change the callback prototype to take
the netmem array from page pool.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/9d8549adb7ef6672daf2d8a52858ce5926279a82.1774261953.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-01 10:21:12 -06:00
Pavel Begunkov
48f253d65d io_uring/zcrx: warn on alloc with non-empty pp cache
Page pool ensures the cache is empty before asking to refill it. Warn if
the assumption is violated.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/9c9792d6e65f3780d57ff83b6334d341ed9a5f29.1774261953.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-01 10:21:12 -06:00
Pavel Begunkov
7df542a665 io_uring/zcrx: move count check into zcrx_get_free_niov
Instead of relying on the caller of __io_zcrx_get_free_niov() to check
that there are free niovs available (i.e. free_count > 0), move the
check into the function and return NULL if can't allocate. It
consolidates the free count checks, and it'll be easier to extend the
niov free list allocator in the future.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/6df04a6b3a6170f86d4345da9864f238311163f9.1774261953.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-01 10:21:12 -06:00
Pavel Begunkov
898ad80d12 io_uring/zcrx: use guards for locking
Convert last several places using manual locking to guards to simplify
the code.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/eb4667cfaf88c559700f6399da9e434889f5b04a.1774261953.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-01 10:21:12 -06:00
Pavel Begunkov
6a55a0a7eb io_uring/zcrx: add a struct for refill queue
Add a new structure that keeps the refill queue state. It's cleaner and
will be useful once we introduce multiple refill queues.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/4ce200da1ff0309c377293b949200f95f80be9ae.1774261953.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-01 10:21:12 -06:00
Pavel Begunkov
ebae09bce4 io_uring/zcrx: use better name for RQ region
Rename "region" to "rq_region" to highlight that it's a refill queue
region.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/ac815790d2477a15826aecaa3d94f2a94ef507e6.1774261953.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-01 10:21:12 -06:00
Pavel Begunkov
825f276491 io_uring/zcrx: implement device-less mode for zcrx
Allow creating a zcrx instance without attaching it to a net device.
All data will be copied through the fallback path. The user is also
expected to use ZCRX_CTRL_FLUSH_RQ to handle overflows as it normally
should even with a netdev, but it becomes even more relevant as there
will likely be no one to automatically pick up buffers.

Apart from that, it follows the zcrx uapi for the I/O path, and is
useful for testing, experimentation, and potentially for the copy
receive path in the future if improved.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/674f8ad679c5a0bc79d538352b3042cf0999596e.1774261953.git.asml.silence@gmail.com
[axboe: fix spelling error in uapi header and commit message]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-01 10:21:12 -06:00
Pavel Begunkov
06fc3b6d38 io_uring/zcrx: extract netdev+area init into a helper
In preparation to following patches, add a function that is responsibly
for looking up a netdev, creating an area, DMA mapping it and opening a
queue.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/88cb6f746ecb496a9030756125419df273d0b003.1774261953.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-01 10:21:12 -06:00
Pavel Begunkov
b8d6eb6c1c io_uring/zcrx: always dma map in advance
zcrx was originally establisihing dma mappings at a late stage when it
was being bound to a page pool. Dma-buf couldn't work this way, so it's
initialised during area creation.

It's messy having them do it at different spots, just move everything to
the area creation time.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/334092a2cbdd4aabd7c025050aa99f05ace89bb5.1774261953.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-01 10:21:12 -06:00
Pavel Begunkov
41041562a7 io_uring/zcrx: fully clean area on error in io_import_umem()
When accounting fails, io_import_umem() sets the page array, etc. and
returns an error expecting that the error handling code will take care
of the rest. To make the next patch simpler, only return a fully
initialised areas from the function.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/3a602b7fb347dbd4da6797ac49b52ea5dedb856d.1774261953.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-01 10:21:12 -06:00
Pavel Begunkov
e5361d25e2 io_uring/zcrx: return back two step unregistration
There are reports where io_uring instance removal takes too long and an
ifq reallocation by another zcrx instance fails. Split zcrx destruction
into two steps similarly how it was before, first close the queue early
but maintain zcrx alive, and then when all inflight requests are
completed, drop the main zcrx reference. For extra protection, mark
terminated zcrx instances in xarray and warn if we double put them.

Cc: stable@vger.kernel.org # 6.19+
Link: https://github.com/axboe/liburing/issues/1550
Reported-by: Youngmin Choi <youngminchoi94@gmail.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/0ce21f0565ab4358668922a28a8a36922dfebf76.1774261953.git.asml.silence@gmail.com
[axboe: NULL ifq before break inside scoped guard]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-01 10:21:12 -06:00
Jens Axboe
aa35dd6bdd io_uring/bpf_filters: retain COW'ed settings on parse failures
If io_parse_restrictions() fails, it ends up clearing any restrictions
currently set. The intent is only to clear whatever it already applied,
but it ends up clearing everything, including whatever settings may have
been applied in a copy-on-write fashion already. Ensure that those are
retained.

Link: https://lore.kernel.org/io-uring/CAK8a0jzF-zaO5ZmdOrmfuxrhXuKg5m5+RDuO7tNvtj=kUYbW7Q@mail.gmail.com/
Reported-by: antonius <bluedragonsec2023@gmail.com>
Fixes: ed82f35b92 ("io_uring: allow registration of per-task restrictions")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-01 08:34:14 -06:00
Jens Axboe
61a11cf481 io_uring: protect remaining lockless ctx->rings accesses with RCU
Commit 9618908026 addressed one case of ctx->rings being potentially
accessed while a resize is happening on the ring, but there are still
a few others that need handling. Add a helper for retrieving the
rings associated with an io_uring context, and add some sanity checking
to that to catch bad uses. ->rings_rcu is always valid, as long as it's
used within RCU read lock. Any use of ->rings_rcu or ->rings inside
either ->uring_lock or ->completion_lock is sane as well.

Do the minimum fix for the current kernel, but set it up such that this
basic infra can be extended for later kernels to make this harder to
mess up in the future.

Thanks to Junxi Qian for finding and debugging this issue.

Cc: stable@vger.kernel.org
Fixes: 79cfe9e59c ("io_uring/register: add IORING_REGISTER_RESIZE_RINGS")
Reviewed-by: Junxi Qian <qjx1298677004@gmail.com>
Tested-by: Junxi Qian <qjx1298677004@gmail.com>
Link: https://lore.kernel.org/io-uring/20260330172348.89416-1-qjx1298677004@gmail.com/
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-01 08:34:11 -06:00
Qi Tang
111a12b422 io_uring/rsrc: reject zero-length fixed buffer import
validate_fixed_range() admits buf_addr at the exact end of the
registered region when len is zero, because the check uses strict
greater-than (buf_end > imu->ubuf + imu->len).  io_import_fixed()
then computes offset == imu->len, which causes the bvec skip logic
to advance past the last bio_vec entry and read bv_offset from
out-of-bounds slab memory.

Return early from io_import_fixed() when len is zero.  A zero-length
import has no data to transfer and should not walk the bvec array
at all.

  BUG: KASAN: slab-out-of-bounds in io_import_reg_buf+0x697/0x7f0
  Read of size 4 at addr ffff888002bcc254 by task poc/103
  Call Trace:
   io_import_reg_buf+0x697/0x7f0
   io_write_fixed+0xd9/0x250
   __io_issue_sqe+0xad/0x710
   io_issue_sqe+0x7d/0x1100
   io_submit_sqes+0x86a/0x23c0
   __do_sys_io_uring_enter+0xa98/0x1590
  Allocated by task 103:
  The buggy address is located 12 bytes to the right of
   allocated 584-byte region [ffff888002bcc000, ffff888002bcc248)

Fixes: 8622b20f23 ("io_uring: add validate_fixed_range() for validate fixed buffer")
Signed-off-by: Qi Tang <tpluszz77@gmail.com>
Link: https://patch.msgid.link/20260329164936.240871-1-tpluszz77@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-29 14:03:55 -06:00
Junxi Qian
b948f9d5d3 io_uring/net: fix slab-out-of-bounds read in io_bundle_nbufs()
sqe->len is __u32 but gets stored into sr->len which is int. When
userspace passes sqe->len values exceeding INT_MAX (e.g. 0xFFFFFFFF),
sr->len overflows to a negative value. This negative value propagates
through the bundle recv/send path:

  1. io_recv(): sel.val = sr->len (ssize_t gets -1)
  2. io_recv_buf_select(): arg.max_len = sel->val (size_t gets
     0xFFFFFFFFFFFFFFFF)
  3. io_ring_buffers_peek(): buf->len is not clamped because max_len
     is astronomically large
  4. iov[].iov_len = 0xFFFFFFFF flows into io_bundle_nbufs()
  5. io_bundle_nbufs(): min_t(int, 0xFFFFFFFF, ret) yields -1,
     causing ret to increase instead of decrease, creating an
     infinite loop that reads past the allocated iov[] array

This results in a slab-out-of-bounds read in io_bundle_nbufs() from
the kmalloc-64 slab, as nbufs increments past the allocated iovec
entries.

  BUG: KASAN: slab-out-of-bounds in io_bundle_nbufs+0x128/0x160
  Read of size 8 at addr ffff888100ae05c8 by task exp/145
  Call Trace:
   io_bundle_nbufs+0x128/0x160
   io_recv_finish+0x117/0xe20
   io_recv+0x2db/0x1160

Fix this by rejecting negative sr->len values early in both
io_sendmsg_prep() and io_recvmsg_prep(). Since sqe->len is __u32,
any value > INT_MAX indicates overflow and is not a valid length.

Fixes: a05d1f625c ("io_uring/net: support bundles for send")
Cc: stable@vger.kernel.org
Signed-off-by: Junxi Qian <qjx1298677004@gmail.com>
Link: https://patch.msgid.link/20260329153909.279046-1-qjx1298677004@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-29 14:03:14 -06:00
Linus Torvalds
196ef74abd io_uring-7.0-20260327
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Merge tag 'io_uring-7.0-20260327' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux

Pull io_uring fixes from Jens Axboe:
 "Just two small fixes, both fixing regressions added in the fdinfo code
  in 6.19 with the SQE mixed size support"

* tag 'io_uring-7.0-20260327' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
  io_uring/fdinfo: fix OOB read in SQE_MIXED wrap check
  io_uring/fdinfo: fix SQE_MIXED SQE displaying
2026-03-27 15:35:38 -07:00
Nicholas Carlini
5170efd9c3 io_uring/fdinfo: fix OOB read in SQE_MIXED wrap check
__io_uring_show_fdinfo() iterates over pending SQEs and, for 128-byte
SQEs on an IORING_SETUP_SQE_MIXED ring, needs to detect when the second
half of the SQE would be past the end of the sq_sqes array. The current
check tests (++sq_head & sq_mask) == 0, but sq_head is only incremented
when a 128-byte SQE is encountered, not on every iteration. The actual
array index is sq_idx = (i + sq_head) & sq_mask, which can be sq_mask
(the last slot) while the wrap check passes.

Fix by checking sq_idx directly. Keep the sq_head increment so the loop
still skips the second half of the 128-byte SQE on the next iteration.

Fixes: 1cba30bf9f ("io_uring: add support for IORING_SETUP_SQE_MIXED")
Signed-off-by: Nicholas Carlini <nicholas@carlini.com>
Link: https://patch.msgid.link/20260327021823.3138396-1-nicholas@carlini.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-26 20:28:28 -06:00
Jens Axboe
b59efde9e6 io_uring/fdinfo: fix SQE_MIXED SQE displaying
When displaying pending SQEs for a MIXED ring, each 128-byte SQE
increments sq_head to skip the second slot, but the loop counter is not
adjusted. This can cause the loop to read past sq_tail by one entry for
each 128-byte SQE encountered, displaying SQEs that haven't been made
consumable yet by the application.

Match the kernel's own consumption logic in io_init_req() which
decrements what's left when consuming the extra slot.

Fixes: 1cba30bf9f ("io_uring: add support for IORING_SETUP_SQE_MIXED")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-26 07:15:55 -06:00
Christoph Hellwig
0924f6b80d
fs: pass on FTRUNCATE_* flags to do_truncate
Pass the flags one level down to replace the somewhat confusing small
argument, and clean up do_truncate as a result.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260323070205.2939118-3-hch@lst.de
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-03-23 12:41:57 +01:00
Linus Torvalds
c612261bed io_uring-7.0-20260320
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Merge tag 'io_uring-7.0-20260320' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux

Pull io_uring fixes from Jens Axboe:

 - A bit of a work-around for AF_UNIX recv multishot, as the in-kernel
   implementation doesn't properly signal EOF. We'll likely rework this
   one going forward, but the fix is sufficient for now

 - Two fixes for incrementally consumed buffers, for non-pollable files
   and for 0 byte reads

* tag 'io_uring-7.0-20260320' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
  io_uring/kbuf: propagate BUF_MORE through early buffer commit path
  io_uring/kbuf: fix missing BUF_MORE for incremental buffers at EOF
  io_uring/poll: fix multishot recv missing EOF on wakeup race
2026-03-20 09:58:56 -07:00
Jens Axboe
418eab7a6f io_uring/kbuf: propagate BUF_MORE through early buffer commit path
When io_should_commit() returns true (eg for non-pollable files), buffer
commit happens at buffer selection time and sel->buf_list is set to
NULL. When __io_put_kbufs() generates CQE flags at completion time, it
calls __io_put_kbuf_ring() which finds a NULL buffer_list and hence
cannot determine whether the buffer was consumed or not. This means that
IORING_CQE_F_BUF_MORE is never set for non-pollable input with
incrementally consumed buffers.

Likewise for io_buffers_select(), which always commits upfront and
discards the return value of io_kbuf_commit().

Add REQ_F_BUF_MORE to store the result of io_kbuf_commit() during early
commit. Then __io_put_kbuf_ring() can check this flag and set
IORING_F_BUF_MORE accordingy.

Reported-by: Martin Michaelis <code@mgjm.de>
Cc: stable@vger.kernel.org
Fixes: ae98dbf43d ("io_uring/kbuf: add support for incremental buffer consumption")
Link: https://github.com/axboe/liburing/issues/1553
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-19 15:09:48 -06:00
Jens Axboe
3ecd3e0314 io_uring/kbuf: fix missing BUF_MORE for incremental buffers at EOF
For a zero length transfer, io_kbuf_inc_commit() is called with !len.
Since we never enter the while loop to consume the buffers,
io_kbuf_inc_commit() ends up returning true, consuming the buffer. But
if no data was consumed, by definition it cannot have consumed the
buffer. Return false for that case.

Reported-by: Martin Michaelis <code@mgjm.de>
Cc: stable@vger.kernel.org
Fixes: ae98dbf43d ("io_uring/kbuf: add support for incremental buffer consumption")
Link: https://github.com/axboe/liburing/issues/1553
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-19 15:09:40 -06:00
Jens Axboe
f41b075492 io_uring: avoid req->ctx reload in io_req_put_rsrc_nodes()
Cache 'ctx' to avoid it needing to get potentially reloaded.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-17 14:35:00 -06:00
Jens Axboe
3e97c2582f io_uring/rw: use cached file rather than req->file
In io_rw_init_file(), req->file is cached in file, yet the former is
still being used when checking for O_DIRECT. As this is post setting
the kiocb flags, the compiler has to reload req->file. Just use the
locally cached file instead.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-17 14:35:00 -06:00
Jens Axboe
0a6b9ae1f3 io_uring/net: use 'ctx' consistently
There's already a local ctx variable, use it for the io_is_compat()
check as well.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-17 14:35:00 -06:00
Jens Axboe
74dbc0bab5 io_uring/poll: cache req->apoll_events
Avoid a potential reload of ->apoll_events post vfs_poll() by caching it
in a local variable.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-17 14:34:51 -06:00
Jens Axboe
49c21d9a5f io_uring/kbuf: use 'ctx' consistently
There's already a local ctx variable, yet the ring lock and unlock
helpers use req->ctx. use ctx consistently.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-17 14:03:54 -06:00
Jens Axboe
a68ed2df72 io_uring/poll: fix multishot recv missing EOF on wakeup race
When a socket send and shutdown() happen back-to-back, both fire
wake-ups before the receiver's task_work has a chance to run. The first
wake gets poll ownership (poll_refs=1), and the second bumps it to 2.
When io_poll_check_events() runs, it calls io_poll_issue() which does a
recv that reads the data and returns IOU_RETRY. The loop then drains all
accumulated refs (atomic_sub_return(2) -> 0) and exits, even though only
the first event was consumed. Since the shutdown is a persistent state
change, no further wakeups will happen, and the multishot recv can hang
forever.

Check specifically for HUP in the poll loop, and ensure that another
loop is done to check for status if more than a single poll activation
is pending. This ensures we don't lose the shutdown event.

Cc: stable@vger.kernel.org
Fixes: dbc2564cfe ("io_uring: let fast poll support multishot")
Reported-by: Francis Brosseau <francis@malagauche.com>
Link: https://github.com/axboe/liburing/issues/1549
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-17 13:54:08 -06:00
Pavel Begunkov
98f37634b1 io_uring/bpf-ops: implement bpf ops registration
Implement BPF struct ops registration. It's registered off the BPF
path, and can be removed by BPF as well as io_uring. To protect it,
introduce a global lock synchronising registration. ctx->uring_lock can
be nested under it. ctx->bpf_ops is write protected by both locks and
so it's safe to read it under either of them.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/1f46bffd76008de49cbafa2ad77d348810a4f69e.1772109579.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-16 16:15:00 -06:00
Pavel Begunkov
890819248a io_uring/bpf-ops: add kfunc helpers
Add two kfuncs that should cover most of the needs:

1. bpf_io_uring_submit_sqes(), which allows to submit io_uring requests.
   It mirrors the normal user space submission path and follows all
   related io_uring_enter(2) rules. i.e. SQEs are taken from the SQ
   according to head/tail values. In case of IORING_SETUP_SQ_REWIND,
   it'll submit first N entries.

2. bpf_io_uring_get_region() returns a pointer to the specified region,
   where io_uring regions are kernel-userspace shared chunks of memory.
   It takes the size as an argument, which should be a load time
   constant. There are 3 types of regions:
   - IOU_REGION_SQ returns the submission queue.
   - IOU_REGION_CQ stores the CQ, SQ/CQ headers and the sqarray. In
     other words, it gives same memory that would normally be mmap'ed
     with IORING_FEAT_SINGLE_MMAP enabled IORING_OFF_SQ_RING.
   - IOU_REGION_MEM represents the memory / parameter region. It can be
     used to store request indirect parameters and for kernel - user
     communication.

It intentionally provides a thin but flexible API and expects BPF
programs to implement CQ/SQ header parsing, CQ walking, etc. That
mirrors how the normal user space works with rings and should help
to minimise kernel / kfunc helpers changes while introducing new generic
io_uring features.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/967bcc10e94c796eb273998621551b2a21848cde.1772109579.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-16 16:15:00 -06:00
Pavel Begunkov
d0e437b76b io_uring/bpf-ops: implement loop_step with BPF struct_ops
Introduce io_uring BPF struct ops implementing the loop_step callback,
which will allow BPF to overwrite the default io_uring event loop logic.

The callback takes an io_uring context, the main role of which is to be
passed to io_uring kfuncs. The other argument is a struct iou_loop_params,
which BPF can use to request CQ waiting and communicate other parameters.
See the event loop description in the previous patch for more details.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/98db437651ce64e9cbeb611c60bf5887259db09f.1772109579.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-16 16:15:00 -06:00
Pavel Begunkov
033af2b3eb io_uring: introduce callback driven main loop
The io_uring_enter() has a fixed order of execution: it submits
requests, waits for completions, and returns to the user. Allow to
optionally replace it with a custom loop driven by a callback called
loop_step. The basic requirements to the callback is that it should be
able to submit requests, wait for completions, parse them and repeat.
Most of the communication including parameter passing can be implemented
via shared memory.

The callback should return IOU_LOOP_CONTINUE to continue execution or
IOU_LOOP_STOP to return to the user space. Note that the kernel may
decide to prematurely terminate it as well, e.g. in case the process was
signalled or killed.

The hook takes a structure with parameters. It can be used to ask the
kernel to wait for CQEs by setting cq_wait_idx to the CQE index it wants
to wait for. Spurious wake ups are possible and even likely, the callback
is expected to handle it. There will be more parameters in the future
like timeout.

It can be used with kernel callbacks, for example, as a slow path
deprecation mechanism overwiting SQEs and emulating the wanted
behaviour, however it's more useful together with BPF programs
implemented in following patches.

Note that keeping it separately from the normal io_uring wait loop
makes things much simpler and cleaner. It keeps it in one place instead
of spreading a bunch of checks in different places including disabling
the submission path. It holds the lock by default, which is a better fit
for BPF synchronisation and the loop execution model. It nicely avoids
existing quirks like forced wake ups on timeout request completion. And
it should be easier to implement new features.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://patch.msgid.link/a2d369aa1c9dd23ad7edac9220cffc563abcaed6.1772109579.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-16 16:15:00 -06:00
Caleb Sander Mateos
23475637b0 io_uring/uring_cmd: allow non-iopoll cmds with IORING_SETUP_IOPOLL
Currently, creating an io_uring with IORING_SETUP_IOPOLL requires all
requests issued to it to support iopoll. This prevents, for example,
using ublk zero-copy together with IORING_SETUP_IOPOLL, as ublk
zero-copy buffer registrations are performed using a uring_cmd. There's
no technical reason why these non-iopoll uring_cmds can't be supported.
They will either complete synchronously or via an external mechanism
that calls io_uring_cmd_done(), io_uring_cmd_post_mshot_cqe32(), or
io_uring_mshot_cmd_post_cqe(), so they don't need to be polled.

Allow uring_cmd requests to be issued to IORING_SETUP_IOPOLL io_urings
even if their files don't implement ->uring_cmd_iopoll(). For these
uring_cmd requests, skip initializing struct io_kiocb's iopoll fields,
don't set REQ_F_IOPOLL, and don't set IO_URING_F_IOPOLL in issue_flags.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Link: https://patch.msgid.link/20260302172914.2488599-5-csander@purestorage.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-16 16:14:14 -06:00
Caleb Sander Mateos
3a5e96d47f io_uring: count CQEs in io_iopoll_check()
A subsequent commit will allow uring_cmds that don't use iopoll on
IORING_SETUP_IOPOLL io_urings. As a result, CQEs can be posted without
setting the iopoll_completed flag for a request in iopoll_list or going
through task work. For example, a UBLK_U_IO_FETCH_IO_CMDS command could
call io_uring_mshot_cmd_post_cqe() to directly post a CQE. The
io_iopoll_check() loop currently only counts completions posted in
io_do_iopoll() when determining whether the min_events threshold has
been met. It also exits early if there are any existing CQEs before
polling, or if any CQEs are posted while running task work. CQEs posted
via io_uring_mshot_cmd_post_cqe() or other mechanisms won't be counted
against min_events.

Explicitly check the available CQEs in each io_iopoll_check() loop
iteration to account for CQEs posted in any fashion.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Link: https://patch.msgid.link/20260302172914.2488599-4-csander@purestorage.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-16 16:14:14 -06:00
Caleb Sander Mateos
7995be40de io_uring: remove iopoll_queue from struct io_issue_def
The opcode iopoll_queue flag is now redundant with REQ_F_IOPOLL. Only
io_{read,write}{,_fixed}() and io_uring_cmd() set the REQ_F_IOPOLL flag,
and the opcodes with these ->issue() implementations are precisely the
ones that set iopoll_queue. So don't bother checking the iopoll_queue
flag in io_issue_sqe(). Remove the unused flag from struct io_issue_def.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Link: https://patch.msgid.link/20260302172914.2488599-3-csander@purestorage.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-16 16:14:14 -06:00
Caleb Sander Mateos
9165dc4fa9 io_uring: add REQ_F_IOPOLL
A subsequent commit will allow uring_cmds to files that don't implement
->uring_cmd_iopoll() to be issued to IORING_SETUP_IOPOLL io_urings. This
means the ctx's IORING_SETUP_IOPOLL flag isn't sufficient to determine
whether a given request needs to be iopolled.

Introduce a request flag REQ_F_IOPOLL set in ->issue() if a request
needs to be iopolled to completion. Set the flag in io_rw_init_file()
and io_uring_cmd() for requests issued to IORING_SETUP_IOPOLL ctxs. Use
the request flag instead of IORING_SETUP_IOPOLL in places dealing with a
specific request.

A future possibility would be to add an option to enable/disable iopoll
in the io_uring SQE instead of determining it from IORING_SETUP_IOPOLL.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Link: https://patch.msgid.link/20260302172914.2488599-2-csander@purestorage.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-16 16:14:14 -06:00
Jens Axboe
8c55744919 io_uring: mark known and harmless racy ctx->int_flags uses
There are a few of these, where flags are read outside of the
uring_lock, yet it's harmless to race on them.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-16 15:33:10 -06:00
Jens Axboe
f1a424e21c io_uring: switch struct io_ring_ctx internal bitfields to flags
Bitfields cannot be set and checked atomically, and this makes it more
clear that these are indeed in shared storage and must be checked and
set in a sane fashion. This is in preparation for annotating a few of
the known racy, but harmless, flags checking.

No intended functional changes in this patch.

Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-16 15:32:59 -06:00
Jens Axboe
0e46cb553f Merge branch 'io_uring-7.0' into for-7.1/io_uring
Merge upstream io_uring fixes to avoid conflicts in later patches.

* io_uring-7.0:
  io_uring/kbuf: check if target buffer list is still legacy on recycle
  io_uring: fix physical SQE bounds check for SQE_MIXED 128-byte ops
  io_uring/eventfd: use ctx->rings_rcu for flags checking
  io_uring: ensure ctx->rings is stable for task work flags manipulation
  io_uring/bpf_filter: use bpf_prog_run_pin_on_cpu() to prevent migration
  io_uring/register: fix comment about task_no_new_privs
2026-03-14 08:57:15 -06:00
Linus Torvalds
e67bf352a0 io_uring-7.0-20260312
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Merge tag 'io_uring-7.0-20260312' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux

Pull io_uring fixes from Jens Axboe:

 - Fix an inverted true/false comment on task_no_new_privs, from the
   BPF filtering changes merged in this release

 - Use the migration disabling way of running the BPF filters, as the
   io_uring side doesn't do that already

 - Fix an issue with ->rings stability under resize, both for local
   task_work additions and for eventfd signaling

 - Fix an issue with SQE mixed mode, where a bounds check wasn't correct
   for having a 128b SQE

 - Fix an issue where a legacy provided buffer group is changed to to
   ring mapped one while legacy buffers from that group are in flight

* tag 'io_uring-7.0-20260312' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
  io_uring/kbuf: check if target buffer list is still legacy on recycle
  io_uring: fix physical SQE bounds check for SQE_MIXED 128-byte ops
  io_uring/eventfd: use ctx->rings_rcu for flags checking
  io_uring: ensure ctx->rings is stable for task work flags manipulation
  io_uring/bpf_filter: use bpf_prog_run_pin_on_cpu() to prevent migration
  io_uring/register: fix comment about task_no_new_privs
2026-03-13 10:09:35 -07:00