| Age | Commit message (Collapse) | Author |
|---|
|
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
|
|
When IORING_SETUP_SQE_MIXED is used without IORING_SETUP_NO_SQARRAY,
the boundary check for 128-byte SQE operations in io_init_req()
validated the logical SQ head position rather than the physical SQE
index.
The existing check:
!(ctx->cached_sq_head & (ctx->sq_entries - 1))
ensures the logical position isn't at the end of the ring, which is
correct for NO_SQARRAY rings where physical == logical. However, when
sq_array is present, an unprivileged user can remap any logical
position to an arbitrary physical index via sq_array. Setting
sq_array[N] = sq_entries - 1 places a 128-byte operation at the last
physical SQE slot, causing the 128-byte memcpy in
io_uring_cmd_sqe_copy() to read 64 bytes past the end of the SQE
array.
Replace the cached_sq_head alignment check with a direct validation
of the physical SQE index, which correctly handles both sq_array and
NO_SQARRAY cases.
Fixes: 1cba30bf9fdd ("io_uring: add support for IORING_SETUP_SQE_MIXED")
Signed-off-by: Tom Ryan <ryan36005@gmail.com>
Link: https://patch.msgid.link/20260310052003.72871-1-ryan36005@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
If DEFER_TASKRUN | SETUP_TASKRUN is used and task work is added while
the ring is being resized, it's possible for the OR'ing of
IORING_SQ_TASKRUN to happen in the small window of swapping into the
new rings and the old rings being freed.
Prevent this by adding a 2nd ->rings pointer, ->rings_rcu, which is
protected by RCU. The task work flags manipulation is inside RCU
already, and if the resize ring freeing is done post an RCU synchronize,
then there's no need to add locking to the fast path of task work
additions.
Note: this is only done for DEFER_TASKRUN, as that's the only setup mode
that supports ring resizing. If this ever changes, then they too need to
use the io_ctx_mark_taskrun() helper.
Link: https://lore.kernel.org/io-uring/20260309062759.482210-1-naup96721@gmail.com/
Cc: stable@vger.kernel.org
Fixes: 79cfe9e59c2a ("io_uring/register: add IORING_REGISTER_RESIZE_RINGS")
Reported-by: Hao-Yu Yang <naup96721@gmail.com>
Suggested-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
|
|
io_key_has_sqarray static branch can be easily switched on/off by the
user every time patching the kernel. That can be very disruptive as it
might require heavy synchronisation across all CPUs. Use deferred static
keys, which can rate-limit it by deferring, batching and potentially
effectively eliminating dec+inc pairs.
Fixes: 9b296c625ac1d ("io_uring: static_key for !IORING_SETUP_NO_SQARRAY")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
In io_ring_ctx_wait_and_kill(), struct creds *creds is used to
iterate and prune credentials. But the correct type is struct cred.
This doesn't matter as the variable isn't used at all, only the index
is used. But it's confusing using a type that isn't valid, so fix it
up.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
io_uring_sanitise_params() already rejects flags that include both
IORING_SETUP_SQPOLL and IORING_SETUP_DEFER_TASKRUN. So it's unnecessary
to check IORING_SETUP_SQPOLL in io_uring_create() when
IORING_SETUP_DEFER_TASKRUN has already been checked. Drop the
!(ctx->flags & IORING_SETUP_SQPOLL) check for the task_complete case.
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux
Pull io_uring bpf filters from Jens Axboe:
"This adds support for both cBPF filters for io_uring, as well as task
inherited restrictions and filters.
seccomp and io_uring don't play along nicely, as most of the
interesting data to filter on resides somewhat out-of-band, in the
submission queue ring.
As a result, things like containers and systemd that apply seccomp
filters, can't filter io_uring operations.
That leaves them with just one choice if filtering is critical -
filter the actual io_uring_setup(2) system call to simply disallow
io_uring. That's rather unfortunate, and has limited us because of it.
io_uring already has some filtering support. It requires the ring to
be setup in a disabled state, and then a filter set can be applied.
This filter set is completely bi-modal - an opcode is either enabled
or it's not. Once a filter set is registered, the ring can be enabled.
This is very restrictive, and it's not useful at all to systemd or
containers which really want both broader and more specific control.
This first adds support for cBPF filters for opcodes, which enables
tighter control over what exactly a specific opcode may do. As
examples, specific support is added for IORING_OP_OPENAT/OPENAT2,
allowing filtering on resolve flags. And another example is added for
IORING_OP_SOCKET, allowing filtering on domain/type/protocol. These
are both common use cases. cBPF was chosen rather than eBPF, because
the latter is often restricted in containers as well.
These filters are run post the init phase of the request, which allows
filters to even dip into data that is being passed in struct in user
memory, as the init side of requests make that data stable by bringing
it into the kernel. This allows filtering without needing to copy this
data twice, or have filters etc know about the exact layout of the
user data. The filters get the already copied and sanitized data
passed.
On top of that support is added for per-task filters, meaning that any
ring created with a task that has a per-task filter will get those
filters applied when it's created. These filters are inherited across
fork as well. Once a filter has been registered, any further added
filters may only further restrict what operations are permitted.
Filters cannot change the return value of an operation, they can only
permit or deny it based on the contents"
* tag 'io_uring-bpf-restrictions.4-20260206' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
io_uring: allow registration of per-task restrictions
io_uring: add task fork hook
io_uring/bpf_filter: add ref counts to struct io_bpf_filter
io_uring/bpf_filter: cache lookup table in ctx->bpf_filters
io_uring/bpf_filter: allow filtering on contents of struct open_how
io_uring/net: allow filtering on IORING_OP_SOCKET data
io_uring: add support for BPF filtering for opcode restrictions
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux
Pull io_uring updates from Jens Axboe:
- Clean up the IORING_SETUP_R_DISABLED and submitter task checking,
mostly just in preparation for relaxing the locking for SINGLE_ISSUER
in the future.
- Improve IOPOLL by using a doubly linked list to manage completions.
Previously it was singly listed, which meant that to complete request
N in the chain 0..N-1 had to have completed first. With a doubly
linked list we can complete whatever request completes in that order,
rather than need to wait for a consecutive range to be available.
This reduces latencies.
- Improve the restriction setup and checking. Mostly in preparation for
adding further features on top of that. Coming in a separate pull
request.
- Split out task_work and wait handling into separate files. These are
mostly nicely abstracted already, but still remained in the
io_uring.c file which is on the larger side.
- Use GFP_KERNEL_ACCOUNT in a few more spots, where appropriate.
- Ensure even the idle io-wq worker exits if a task no longer has any
rings open.
- Add support for a non-circular submission queue.
By default, the SQ ring keeps moving around, even if only a few
entries are used for each submission. This can be wasteful in terms
of cachelines.
If IORING_SETUP_SQ_REWIND is set for the ring when created, each
submission will start at offset 0 instead of where we last left off
doing submissions.
- Various little cleanups
* tag 'for-7.0/io_uring-20260206' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (30 commits)
io_uring/kbuf: fix memory leak if io_buffer_add_list fails
io_uring: Add SPDX id lines to remaining source files
io_uring: allow io-wq workers to exit when unused
io_uring/io-wq: add exit-on-idle state
io_uring/net: don't continue send bundle if poll was required for retry
io_uring/rsrc: use GFP_KERNEL_ACCOUNT consistently
io_uring/futex: use GFP_KERNEL_ACCOUNT for futex data allocation
io_uring/io-wq: handle !sysctl_hung_task_timeout_secs
io_uring: fix bad indentation for setup flags if statement
io_uring/rsrc: take unsigned index in io_rsrc_node_lookup()
io_uring: introduce non-circular SQ
io_uring: split out CQ waiting code into wait.c
io_uring: split out task work code into tw.c
io_uring/io-wq: don't trigger hung task for syzbot craziness
io_uring: add IO_URING_EXIT_WAIT_MAX definition
io_uring/sync: validate passed in offset
io_uring/eventfd: remove unused ctx->evfd_last_cq_tail member
io_uring/timeout: annotate data race in io_flush_timeouts()
io_uring/uring_cmd: explicitly disallow cancelations for IOPOLL
io_uring: fix IOPOLL with passthrough I/O
...
|
|
Currently io_uring supports restricting operations on a per-ring basis.
To use those, the ring must be setup in a disabled state by setting
IORING_SETUP_R_DISABLED. Then restrictions can be set for the ring, and
the ring can then be enabled.
This commit adds support for IORING_REGISTER_RESTRICTIONS with ring_fd
== -1, like the other "blind" register opcodes which work on the task
rather than a specific ring. This allows registration of the same kind
of restrictions as can been done on a specific ring, but with the task
itself. Once done, any ring created will inherit these restrictions.
If a restriction filter is registered with a task, then it's inherited
on fork for its children. Children may only further restrict operations,
not extend them.
Inheriting restrictions include both the classic
IORING_REGISTER_RESTRICTIONS based restrictions, as well as the BPF
filters that have been registered with the task via
IORING_REGISTER_BPF_FILTER.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Currently a few pointer dereferences need to be made to both check if
BPF filters are installed, and then also to retrieve the actual filter
for the opcode. Cache the table in ctx->bpf_filters to avoid that.
Add a bit of debug info on ring exit to show if we ever got this wrong.
Small risk of that given that the table is currently only updated in one
spot, but once task forking is enabled, that will add one more spot.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Add support for loading classic BPF programs with io_uring to provide
fine-grained filtering of SQE operations. Unlike
IORING_REGISTER_RESTRICTIONS which only allows bitmap-based allow/deny
of opcodes, BPF filters can inspect request attributes and make dynamic
decisions.
The filter is registered via IORING_REGISTER_BPF_FILTER with a struct
io_uring_bpf:
struct io_uring_bpf_filter {
__u32 opcode; /* io_uring opcode to filter */
__u32 flags;
__u32 filter_len; /* number of BPF instructions */
__u32 resv;
__u64 filter_ptr; /* pointer to BPF filter */
__u64 resv2[5];
};
enum {
IO_URING_BPF_CMD_FILTER = 1,
};
struct io_uring_bpf {
__u16 cmd_type; /* IO_URING_BPF_* values */
__u16 cmd_flags; /* none so far */
__u32 resv;
union {
struct io_uring_bpf_filter filter;
};
};
and the filters get supplied a struct io_uring_bpf_ctx:
struct io_uring_bpf_ctx {
__u64 user_data;
__u8 opcode;
__u8 sqe_flags;
__u8 pdu_size;
__u8 pad[5];
};
where it's possible to filter on opcode and sqe_flags, with pdu_size
indicating how much extra data is being passed in beyond the pad field.
This will used for specific finer grained filtering inside an opcode.
An example of that for sockets is in one of the following patches.
Anything the opcode supports can end up in this struct, populated by
the opcode itself, and hence can be filtered for.
Filters have the following semantics:
- Return 1 to allow the request
- Return 0 to deny the request with -EACCES
- Multiple filters can be stacked per opcode. All filters must
return 1 for the opcode to be allowed.
- Filters are evaluated in registration order (most recent first)
The implementation uses classic BPF (cBPF) rather than eBPF for as
that's required for containers, and since they can be used by any
user in the system.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
smatch complains about this:
smatch warnings:
io_uring/io_uring.c:2741 io_uring_sanitise_params() warn: if statement not indented
hence fix it up.
Link: https://lore.kernel.org/all/202601231651.HeTmPS8C-lkp@intel.com/
Fixes: 5247c034a67f ("io_uring: introduce non-circular SQ")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/202601231651.HeTmPS8C-lkp@intel.com/
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Outside of SQPOLL, normally SQ entries are consumed by the time the
submission syscall returns. For those cases we don't need a circular
buffer and the head/tail tracking, instead the kernel can assume that
entries always start from the beginning of the SQ at index 0. This patch
introduces a setup flag doing exactly that. It's a simpler and helps
to keeps SQEs hot in cache.
The feature is optional and enabled by setting IORING_SETUP_SQ_REWIND.
The flag is rejected if passed together with SQPOLL as it'd require
waiting for SQ before each submission. It also requires
IORING_SETUP_NO_SQARRAY, which can be supported but it's unlikely there
will be users, so leave more space for future optimisations.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Move the completion queue waiting and scheduling code out of io_uring.c
into a dedicated wait.c file. This further removes code out of the
main io_uring C and header file, and into a topical new file.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Move the task work handling code out of io_uring.c into a new tw.c file.
This includes the local work, normal work, and fallback work handling
infrastructure.
The associated tw.h header contains io_should_terminate_tw() as a static
inline helper, along with the necessary function declarations.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Add the timeout we normally wait before complaining about things being
stuck waiting for cancelations to complete as a define, and use it in
io_ring_exit_work().
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
With IORING_SETUP_DEFER_TASKRUN, task work is queued to ctx->work_llist
(local work) rather than the fallback list. During io_ring_exit_work(),
io_move_task_work_from_local() was called once before the cancel loop,
moving work from work_llist to fallback_llist.
However, task work can be added to work_llist during the cancel loop
itself. There are two cases:
1) io_kill_timeouts() is called from io_uring_try_cancel_requests() to
cancel pending timeouts, and it adds task work via io_req_queue_tw_complete()
for each cancelled timeout:
2) URING_CMD requests like ublk can be completed via
io_uring_cmd_complete_in_task() from ublk_queue_rq() during canceling,
given ublk request queue is only quiesced when canceling the 1st uring_cmd.
Since io_allowed_defer_tw_run() returns false in io_ring_exit_work()
(kworker != submitter_task), io_run_local_work() is never invoked,
and the work_llist entries are never processed. This causes
io_uring_try_cancel_requests() to loop indefinitely, resulting in
100% CPU usage in kworker threads.
Fix this by moving io_move_task_work_from_local() inside the cancel
loop, ensuring any work on work_llist is moved to fallback before
each cancel attempt.
Cc: stable@vger.kernel.org
Fixes: c0e0d6ba25f1 ("io_uring: add IORING_SETUP_DEFER_TASKRUN")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
It's quite likely that only register opcode restrictions exists, in
which case we'd never need to check the normal opcodes. Split
ctx->restricted into two separate fields, one for I/O opcodes, and one
for register opcodes.
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Just a cleanup, makes the code easier to read without too many dependent
nested checks.
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
__io_msg_ring_data() checks that the target_ctx isn't
IORING_SETUP_R_DISABLED before calling io_msg_data_remote(), which calls
io_msg_remote_post(). So submitter_task can't be modified concurrently
with the read in io_msg_remote_post(). Additionally, submitter_task must
exist, as io_msg_data_remote() is only called for io_msg_need_remote(),
i.e. task_complete is set, which requires IORING_SETUP_DEFER_TASKRUN,
which in turn requires IORING_SETUP_SINGLE_ISSUER. And submitter_task is
assigned in io_uring_create() or io_register_enable_rings() before
enabling any IORING_SETUP_SINGLE_ISSUER io_ring_ctx.
Similarly, io_msg_send_fd() checks IORING_SETUP_R_DISABLED and
io_msg_need_remote() before calling io_msg_fd_remote(). submitter_task
therefore can't be modified concurrently with the read in
io_msg_fd_remote() and must be non-null.
io_register_enable_rings() can't run concurrently because it's called
from io_uring_register() -> __io_uring_register() with uring_lock held.
Thus, replace the READ_ONCE() and WRITE_ONCE() of submitter_task with
plain loads and stores. And remove the NULL checks of submitter_task in
io_msg_remote_post() and io_msg_fd_remote().
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Joanne Koong <joannelkoong@gmail.com>
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
io_uring_enter(), __io_msg_ring_data(), and io_msg_send_fd() read
ctx->flags and ctx->submitter_task without holding the ctx's uring_lock.
This means they may race with the assignment to ctx->submitter_task and
the clearing of IORING_SETUP_R_DISABLED from ctx->flags in
io_register_enable_rings(). Ensure the correct ordering of the
ctx->flags and ctx->submitter_task memory accesses by storing to
ctx->flags using release ordering and loading it using acquire ordering.
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Fixes: 4add705e4eeb ("io_uring: remove io_register_submitter")
Reviewed-by: Joanne Koong <joannelkoong@gmail.com>
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Clean up some left overs of refactoring io_uring into multiple files.
Compile tested with a few configurations.
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
ctx->tcxt_list holds the tasks using this ring, and it's currently
protected by the normal ctx->uring_lock. However, this can cause a
circular locking issue, as reported by syzbot, where cancelations off
exec end up needing to remove an entry from this list:
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Tainted: G L
------------------------------------------------------
syz.0.9999/12287 is trying to acquire lock:
ffff88805851c0a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_uring_del_tctx_node+0xf0/0x2c0 io_uring/tctx.c:179
but task is already holding lock:
ffff88802db5a2e0 (&sig->cred_guard_mutex){+.+.}-{4:4}, at: prepare_bprm_creds fs/exec.c:1360 [inline]
ffff88802db5a2e0 (&sig->cred_guard_mutex){+.+.}-{4:4}, at: bprm_execve+0xb9/0x1400 fs/exec.c:1733
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&sig->cred_guard_mutex){+.+.}-{4:4}:
__mutex_lock_common kernel/locking/mutex.c:614 [inline]
__mutex_lock+0x187/0x1350 kernel/locking/mutex.c:776
proc_pid_attr_write+0x547/0x630 fs/proc/base.c:2837
vfs_write+0x27e/0xb30 fs/read_write.c:684
ksys_write+0x145/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #1 (sb_writers#3){.+.+}-{0:0}:
percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline]
percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
__sb_start_write include/linux/fs/super.h:19 [inline]
sb_start_write+0x4d/0x1c0 include/linux/fs/super.h:125
mnt_want_write+0x41/0x90 fs/namespace.c:499
open_last_lookups fs/namei.c:4529 [inline]
path_openat+0xadd/0x3dd0 fs/namei.c:4784
do_filp_open+0x1fa/0x410 fs/namei.c:4814
io_openat2+0x3e0/0x5c0 io_uring/openclose.c:143
__io_issue_sqe+0x181/0x4b0 io_uring/io_uring.c:1792
io_issue_sqe+0x165/0x1060 io_uring/io_uring.c:1815
io_queue_sqe io_uring/io_uring.c:2042 [inline]
io_submit_sqe io_uring/io_uring.c:2320 [inline]
io_submit_sqes+0xbf4/0x2140 io_uring/io_uring.c:2434
__do_sys_io_uring_enter io_uring/io_uring.c:3280 [inline]
__se_sys_io_uring_enter+0x2e0/0x2b60 io_uring/io_uring.c:3219
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #0 (&ctx->uring_lock){+.+.}-{4:4}:
check_prev_add kernel/locking/lockdep.c:3165 [inline]
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain kernel/locking/lockdep.c:3908 [inline]
__lock_acquire+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237
lock_acquire+0x107/0x340 kernel/locking/lockdep.c:5868
__mutex_lock_common kernel/locking/mutex.c:614 [inline]
__mutex_lock+0x187/0x1350 kernel/locking/mutex.c:776
io_uring_del_tctx_node+0xf0/0x2c0 io_uring/tctx.c:179
io_uring_clean_tctx+0xd4/0x1a0 io_uring/tctx.c:195
io_uring_cancel_generic+0x6ca/0x7d0 io_uring/cancel.c:646
io_uring_task_cancel include/linux/io_uring.h:24 [inline]
begin_new_exec+0x10ed/0x2440 fs/exec.c:1131
load_elf_binary+0x9f8/0x2d70 fs/binfmt_elf.c:1010
search_binary_handler fs/exec.c:1669 [inline]
exec_binprm fs/exec.c:1701 [inline]
bprm_execve+0x92e/0x1400 fs/exec.c:1753
do_execveat_common+0x510/0x6a0 fs/exec.c:1859
do_execve fs/exec.c:1933 [inline]
__do_sys_execve fs/exec.c:2009 [inline]
__se_sys_execve fs/exec.c:2004 [inline]
__x64_sys_execve+0x94/0xb0 fs/exec.c:2004
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
other info that might help us debug this:
Chain exists of:
&ctx->uring_lock --> sb_writers#3 --> &sig->cred_guard_mutex
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&sig->cred_guard_mutex);
lock(sb_writers#3);
lock(&sig->cred_guard_mutex);
lock(&ctx->uring_lock);
*** DEADLOCK ***
1 lock held by syz.0.9999/12287:
#0: ffff88802db5a2e0 (&sig->cred_guard_mutex){+.+.}-{4:4}, at: prepare_bprm_creds fs/exec.c:1360 [inline]
#0: ffff88802db5a2e0 (&sig->cred_guard_mutex){+.+.}-{4:4}, at: bprm_execve+0xb9/0x1400 fs/exec.c:1733
stack backtrace:
CPU: 0 UID: 0 PID: 12287 Comm: syz.0.9999 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2043
check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175
check_prev_add kernel/locking/lockdep.c:3165 [inline]
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain kernel/locking/lockdep.c:3908 [inline]
__lock_acquire+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237
lock_acquire+0x107/0x340 kernel/locking/lockdep.c:5868
__mutex_lock_common kernel/locking/mutex.c:614 [inline]
__mutex_lock+0x187/0x1350 kernel/locking/mutex.c:776
io_uring_del_tctx_node+0xf0/0x2c0 io_uring/tctx.c:179
io_uring_clean_tctx+0xd4/0x1a0 io_uring/tctx.c:195
io_uring_cancel_generic+0x6ca/0x7d0 io_uring/cancel.c:646
io_uring_task_cancel include/linux/io_uring.h:24 [inline]
begin_new_exec+0x10ed/0x2440 fs/exec.c:1131
load_elf_binary+0x9f8/0x2d70 fs/binfmt_elf.c:1010
search_binary_handler fs/exec.c:1669 [inline]
exec_binprm fs/exec.c:1701 [inline]
bprm_execve+0x92e/0x1400 fs/exec.c:1753
do_execveat_common+0x510/0x6a0 fs/exec.c:1859
do_execve fs/exec.c:1933 [inline]
__do_sys_execve fs/exec.c:2009 [inline]
__se_sys_execve fs/exec.c:2004 [inline]
__x64_sys_execve+0x94/0xb0 fs/exec.c:2004
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff3a8b8f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff3a9a97038 EFLAGS: 00000246 ORIG_RAX: 000000000000003b
RAX: ffffffffffffffda RBX: 00007ff3a8de5fa0 RCX: 00007ff3a8b8f749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000400
RBP: 00007ff3a8c13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff3a8de6038 R14: 00007ff3a8de5fa0 R15: 00007ff3a8f0fa28
</TASK>
Add a separate lock just for the tctx_list, tctx_lock. This can nest
under ->uring_lock, where necessary, and be used separately for list
manipulation. For the cancelation off exec side, this removes the
need to grab ->uring_lock, hence fixing the circular locking
dependency.
Reported-by: syzbot+b0e3b77ffaa8a4067ce5@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Allocate the overflowing CQE with GFP_NOWAIT instead of GFP_ATOMIC. This
changes causes allocations to fail earlier in out-of-memory situations,
rather than being deferred. Using GFP_ATOMIC allows a process to exceed
memory limits.
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220794
Signed-off-by: Alexandre Negrel <alexandre@negrel.dev>
Link: https://lore.kernel.org/io-uring/20251229201933.515797-1-alexandre@negrel.dev/
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
io_uring manages issued and pending IOPOLL read/write requests in a
singly linked list. One downside of that is that individual items
cannot easily be removed from that list, and as a result, io_uring
will only complete a completed request N in that list if 0..N-1 are
also complete. For homogenous IO this isn't necessarily an issue,
but if different devices are involved in polling in the same ring, or
if disparate IO from the same device is being polled for, this can
defer completion of some requests unnecessarily.
Move to a doubly linked list for iopoll completions instead, making it
possible to easily complete whatever requests that were polled done
successfully.
Co-developed-by: Fengnan Chang <fengnanchang@gmail.com>
Link: https://lore.kernel.org/io-uring/20251210085501.84261-1-changfengnan@bytedance.com/
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Using min_wait, two timeouts are given:
1) The min_wait timeout, within which up to 'wait_nr' events are
waited for.
2) The overall long timeout, which is entered if no events are generated
in the min_wait window.
If the min_wait has expired, any event being posted must wake the task.
For SQPOLL, that isn't the case, as it won't trigger the io_has_work()
condition, as it will have already processed the task_work that happened
when an event was posted. This causes any event to trigger post the
min_wait to not always cause the waiting application to wakeup, and
instead it will wait until the overall timeout has expired. This can be
shown in a test case that has a 1 second min_wait, with a 5 second
overall wait, even if an event triggers after 1.5 seconds:
axboe@m2max-kvm /d/iouring-mre (master)> zig-out/bin/iouring
info: MIN_TIMEOUT supported: true, features: 0x3ffff
info: Testing: min_wait=1000ms, timeout=5s, wait_nr=4
info: 1 cqes in 5000.2ms
where the expected result should be:
axboe@m2max-kvm /d/iouring-mre (master)> zig-out/bin/iouring
info: MIN_TIMEOUT supported: true, features: 0x3ffff
info: Testing: min_wait=1000ms, timeout=5s, wait_nr=4
info: 1 cqes in 1500.3ms
When the min_wait timeout triggers, reset the number of completions
needed to wake the task. This should ensure that any future events will
wake the task, regardless of how many events it originally wanted to
wait for.
Reported-by: Tip ten Brink <tip@tenbrinkmeijs.com>
Cc: stable@vger.kernel.org
Fixes: 1100c4a2656d ("io_uring: add support for batch wait timeout")
Link: https://github.com/axboe/liburing/issues/1477
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux
Pull io_uring updates from Jens Axboe:
- Unify how task_work cancelations are detected, placing it in the
task_work running state rather than needing to check the task state
- Series cleaning up and moving the cancelation code to where it
belongs, in cancel.c
- Cleanup of waitid and futex argument handling
- Add support for mixed sized SQEs. 6.18 added support for mixed sized
CQEs, improving flexibility and efficiency of workloads that need big
CQEs. This adds similar support for SQEs, where the occasional need
for a 128b SQE doesn't necessitate having all SQEs be 128b in size
- Introduce zcrx and SQ/CQ layout queries. The former returns what zcrx
features are available. And both return the ring size information to
help with allocation size calculation for user provided rings like
IORING_SETUP_NO_MMAP and IORING_MEM_REGION_TYPE_USER
- Zcrx updates for 6.19. It includes a bunch of small patches,
IORING_REGISTER_ZCRX_CTRL and RQ flushing and David's work on sharing
zcrx b/w multiple io_uring instances
- Series cleaning up ring initializations, notable deduplicating ring
size and offset calculations. It also moves most of the checking
before doing any allocations, making the code simpler
- Add support for getsockname and getpeername, which is mostly a
trivial hookup after a bit of refactoring on the networking side
- Various fixes and cleanups
* tag 'for-6.19/io_uring-20251201' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (68 commits)
io_uring: Introduce getsockname io_uring cmd
socket: Split out a getsockname helper for io_uring
socket: Unify getsockname and getpeername implementation
io_uring/query: drop unused io_handle_query_entry() ctx arg
io_uring/kbuf: remove obsolete buf_nr_pages and update comments
io_uring/register: use correct location for io_rings_layout
io_uring/zcrx: share an ifq between rings
io_uring/zcrx: add io_fill_zcrx_offsets()
io_uring/zcrx: export zcrx via a file
io_uring/zcrx: move io_zcrx_scrub() and dependencies up
io_uring/zcrx: count zcrx users
io_uring/zcrx: add sync refill queue flushing
io_uring/zcrx: introduce IORING_REGISTER_ZCRX_CTRL
io_uring/zcrx: elide passing msg flags
io_uring/zcrx: use folio_nr_pages() instead of shift operation
io_uring/zcrx: convert to use netmem_desc
io_uring/query: introduce rings info query
io_uring/query: introduce zcrx query
io_uring: move cq/sq user offset init around
io_uring: pre-calculate scq layout
...
|
|
I started to see zcrx data corruptions. That turned out to be due
to CQ tail pointing to a stale entry which happened to be from
a zcrx request. I.e. the tail is incremented without the CQE
memory being changed.
The culprit is __io_cqring_overflow_flush() passing "cqe32=true"
to io_get_cqe_overflow() for non-mixed CQE32 setups, which only
expects it to be set for mixed 32B CQEs and not for SETUP_CQE32.
The fix is slightly hacky, long term it's better to unify mixed and
CQE32 handling.
Fixes: e26dca67fde19 ("io_uring: add support for IORING_SETUP_CQE_MIXED")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Move user SQ/CQ offset initialisation at the end of io_prepare_config()
where it already calculated all information to set it properly.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Move ring layouts calculations into io_prepare_config(), so that more
misconfiguration checking can be done earlier before creating a ctx.
It also deduplicates some code with ring resizing. And as a bonus, now
it initialises params->sq_off.array, which is closer to all other user
offset init, and also applies it to ring resizing, which was previously
missing it.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Add a structure keeping SQ/CQ sizes and offsets. For now it only records
data previously returned from rings_size and the SQ size.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
There will be more information needed during ctx setup, and instead of
passing a handful of pointers around, wrap them all into a new
structure. Add a helper for encapsulating all configuration checks and
preparation, that's also reused for ring resizing.
Note, it indirectly adds a io_uring_sanitise_params() check to ring
resizing, which is a good thing.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Use size_add / size_mul set of functions for rings_size() calculations.
It's more consistent with struct_size(), and errors are preserved across
a series of calculations, so intermediate result checks can be omitted.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
A preparation patch inversing the IORING_SETUP_NO_SQARRAY check, this
way there is only one successful return path from the function, which
will be helpful later.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Merge 6.18-rc io_uring fixes, as certain coming changes depend on some
of these.
* io_uring-6.18:
io_uring/rsrc: don't use blk_rq_nr_phys_segments() as number of bvecs
io_uring/query: return number of available queries
io_uring/rw: ensure allocated iovec gets cleared for early failure
io_uring: fix regbuf vector size truncation
io_uring: fix types for region size calulation
io_uring/zcrx: remove sync refill uapi
io_uring: fix buffer auto-commit for multishot uring_cmd
io_uring: correct __must_hold annotation in io_install_fixed_file
io_uring zcrx: add MAINTAINERS entry
io_uring: Fix code indentation error
io_uring/sqpoll: be smarter on when to update the stime usage
io_uring/sqpoll: switch away from getrusage() for CPU accounting
io_uring: fix incorrect unlikely() usage in io_waitid_prep()
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
io_uring_sanitise_params() sanitises most of the setup flags invariants,
move the IORING_SETUP_FLAGS check from io_uring_setup() into it.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
mem_is_zero() does the job without hand rolled loops, use that to verify
reserved fields of ring params.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
There is no need to pass the user requested number of SQ entries
separately from the main parameter structure io_uring_params. Initialise
it at the beginning and stop passing it in favour of struct
io_uring_params::sq_entries.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
IORING_SETUP_NO_MMAP rings remain user accessible even before the ctx
setup is finalised, so use WRITE_ONCE consistently when initialising
rings.
Fixes: 03d89a2de25bb ("io_uring: support for user allocated memory for rings/sqes")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Add a refcount to struct io_zcrx_ifq to reverse the refcounting
relationship i.e. rings now reference ifqs instead. As a result of this,
remove ctx->refs that an ifq holds on a ring via the page pool memory
provider.
This ref ifq->refs is held by internal users of an ifq, namely rings and
the page pool memory provider associated with an ifq. This is needed to
keep the ifq around until the page pool is destroyed.
Since ifqs now no longer hold refs to ring ctx, there isn't a need to
split the cleanup of ifqs into two: io_shutdown_zcrx_ifqs() in
io_ring_exit_work() while waiting for ctx->refs to drop to 0, and
io_unregister_zcrx_ifqs() after. Remove io_shutdown_zcrx_ifqs().
Signed-off-by: David Wei <dw@davidwei.uk>
Co-developed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Refactor io_free_region() to take user_struct directly, instead of
accessing it from the ring ctx.
Signed-off-by: David Wei <dw@davidwei.uk>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Corrected spelling mistakes in comments
"reuqests" -> "requests", "noifications" -> "notifications",
"seperately" -> "separately").
Fixed a small grammar issue ("then" -> "than").
Updated "flag" -> "flags" in fdinfo.c
Signed-off-by: Alok Tiwari <alok.a.tiwari@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
There's a bunch of code strictly dealing with cancelations, and that
code really belongs in cancel.c rather than in the core io_uring.c file.
Move the code there. Mostly mechanical, only real oddity here is that
struct io_defer_entry now needs to be visible across both io_uring.c
and cancel.c.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Yet another function that should be in cancel.c, move it over.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Move io_match_task_safe() and helpers into cancel.c, where it belongs.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
In preparation for uring_cmd implementations to implement functions
with the io_req_tw_func_t signature, introduce a wrapper struct
io_tw_req to hide the struct io_kiocb * argument. The intention is for
only the io_uring core to access the inner struct io_kiocb *. uring_cmd
implementations should instead call a helper from io_uring/cmd.h to
convert struct io_tw_req to struct io_uring_cmd *.
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
io_fallback_req_func() calls io_should_terminate_tw() on each req's ctx.
But since the reqs all come from the ctx's fallback_llist, req->ctx will
be ctx for all of the reqs. Therefore, compute ts.cancel as
io_should_terminate_tw(ctx) just once, outside the loop.
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
io_submit_sqes() shouldn't be stepping into its main loop when there is
nothing to submit, i.e. nr=0. Fix 0 submission queue entries checks,
which should follow after all user input truncations.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
