linux-stable.git/io_uring/io_uring.c, branch v6.9.2

io_uring: Fix io_cqring_wait() not restoring sigmask on get_timespec64() failure

2024-04-06T02:05:41+00:00

This bug was introduced in commit 950e79dd7313 ("io_uring: minor
io_cqring_wait() optimization"), which was made in preparation for
adc8682ec690 ("io_uring: Add support for napi_busy_poll"). The latter
got reverted in cb3182167325 ("Revert "io_uring: Add support for
napi_busy_poll""), so simply undo the former as well.

Cc: stable@vger.kernel.org
Fixes: 950e79dd7313 ("io_uring: minor io_cqring_wait() optimization")
Signed-off-by: Alexey Izbyshev 
Link: https://lore.kernel.org/r/20240405125551.237142-1-izbyshev@ispras.ru
Signed-off-by: Jens Axboe

io_uring/kbuf: hold io_buffer_list reference over mmap

2024-04-03T01:03:27+00:00

If we look up the kbuf, ensure that it doesn't get unregistered until
after we're done with it. Since we're inside mmap, we cannot safely use
the io_uring lock. Rely on the fact that we can lookup the buffer list
under RCU now and grab a reference to it, preventing it from being
unregistered until we're done with it. The lookup returns the
io_buffer_list directly with it referenced.

Cc: stable@vger.kernel.org # v6.4+
Fixes: 5cf4f52e6d8a ("io_uring: free io_buffer_list entries via RCU")
Signed-off-by: Jens Axboe

io_uring/kbuf: get rid of lower BGID lists

2024-04-03T01:03:13+00:00

Just rely on the xarray for any kind of bgid. This simplifies things, and
it really doesn't bring us much, if anything.

Cc: stable@vger.kernel.org # v6.4+
Signed-off-by: Jens Axboe

io_uring: use private workqueue for exit work

2024-04-02T13:35:16+00:00

Rather than use the system unbound event workqueue, use an io_uring
specific one. This avoids dependencies with the tty, which also uses
the system_unbound_wq, and issues flushes of said workqueue from inside
its poll handling.

Cc: stable@vger.kernel.org
Reported-by: Rasmus Karlsson 
Tested-by: Rasmus Karlsson 
Tested-by: Iskren Chernev 
Link: https://github.com/axboe/liburing/issues/1113
Signed-off-by: Jens Axboe

io_uring: disable io-wq execution of multishot NOWAIT requests

2024-04-01T17:46:22+00:00

Do the same check for direct io-wq execution for multishot requests that
commit 2a975d426c82 did for the inline execution, and disable multishot
mode (and revert to single shot) if the file type doesn't support NOWAIT,
and isn't opened in O_NONBLOCK mode. For multishot to work properly, it's
a requirement that nonblocking read attempts can be done.

Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe

io_uring: clear opcode specific data for an early failure

2024-03-16T17:24:50+00:00

If failure happens before the opcode prep handler is called, ensure that
we clear the opcode specific area of the request, which holds data
specific to that request type. This prevents errors where opcode
handlers either don't get to clear per-request private data since prep
isn't even called.

Reported-and-tested-by: syzbot+f8e9a371388aa62ecab4@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe

io_uring: Fix release of pinned pages when __io_uaddr_map fails

2024-03-13T22:08:25+00:00

Looking at the error path of __io_uaddr_map, if we fail after pinning
the pages for any reasons, ret will be set to -EINVAL and the error
handler won't properly release the pinned pages.

I didn't manage to trigger it without forcing a failure, but it can
happen in real life when memory is heavily fragmented.

Signed-off-by: Gabriel Krisman Bertazi 
Fixes: 223ef4743164 ("io_uring: don't allow IORING_SETUP_NO_MMAP rings on highmem pages")
Link: https://lore.kernel.org/r/20240313213912.1920-1-krisman@suse.de
Signed-off-by: Jens Axboe

io_uring: simplify io_pages_free

2024-03-13T20:50:42+00:00

We never pass a null (top-level) pointer, remove the check.

Signed-off-by: Pavel Begunkov 
Link: https://lore.kernel.org/r/0e1a46f9a5cd38e6876905e8030bdff9b0845e96.1710343154.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe

io_uring: clean rings on NO_MMAP alloc fail

2024-03-12T15:21:36+00:00

We make a few cancellation judgements based on ctx->rings, so let's
zero it afer deallocation for IORING_SETUP_NO_MMAP just like it's
done with the mmap case. Likely, it's not a real problem, but zeroing
is safer and better tested.

Cc: stable@vger.kernel.org
Fixes: 03d89a2de25bbc ("io_uring: support for user allocated memory for rings/sqes")
Signed-off-by: Pavel Begunkov 
Link: https://lore.kernel.org/r/9ff6cdf91429b8a51699c210e1f6af6ea3f8bdcf.1710255382.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe

io_uring: don't save/restore iowait state

2024-03-11T21:02:59+00:00

This kind of state is per-syscall, and since we're doing the waiting off
entering the io_uring_enter(2) syscall, there's no way that iowait can
already be set for this case. Simplify it by setting it if we need to,
and always clearing it to 0 when done.

Fixes: 7b72d661f1f2 ("io_uring: gate iowait schedule on having pending requests")
Signed-off-by: Jens Axboe