pm24.git/io_uring, branch v6.2-rc3

io_uring: fix CQ waiting timeout handling

2023-01-05T15:04:47Z

Jiffy to ktime CQ waiting conversion broke how we treat timeouts, in particular we rearm it anew every time we get into io_cqring_wait_schedule() without adjusting the timeout. Waiting for 2 CQEs and getting a task_work in the middle may double the timeout value, or even worse in some cases task may wait indefinitely. Cc: stable@vger.kernel.org Fixes: 228339662b398 ("io_uring: don't convert to jiffies for waiting on timeouts") Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/f7bffddd71b08f28a877d44d37ac953ddb01590d.1672915663.git.asml.silence@gmail.com Signed-off-by: Jens Axboe

io_uring: lockdep annotate CQ locking

2023-01-04T02:05:41Z

Locking around CQE posting is complex and depends on options the ring is created with, add more thorough lockdep annotations checking all invariants. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/aa3770b4eacae3915d782cc2ab2f395a99b4b232.1672795976.git.asml.silence@gmail.com Signed-off-by: Jens Axboe

io_uring: pin context while queueing deferred tw

2023-01-04T02:03:28Z

Unlike normal tw, nothing prevents deferred tw to be executed right after an tw item added to ->work_llist in io_req_local_work_add(). For instance, the waiting task may get waken up by CQ posting or a normal tw. Thus we need to pin the ring for the rest of io_req_local_work_add() Cc: stable@vger.kernel.org Fixes: c0e0d6ba25f18 ("io_uring: add IORING_SETUP_DEFER_TASKRUN") Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/1a79362b9c10b8523ef70b061d96523650a23344.1672795998.git.asml.silence@gmail.com Signed-off-by: Jens Axboe

io_uring/io-wq: free worker if task_work creation is canceled

2023-01-02T23:49:46Z

If we cancel the task_work, the worker will never come into existance. As this is the last reference to it, ensure that we get it freed appropriately. Cc: stable@vger.kernel.org Reported-by: 진호 Signed-off-by: Jens Axboe

io_uring: check for valid register opcode earlier

2022-12-23T13:40:32Z

We only check the register opcode value inside the restricted ring section, move it into the main io_uring_register() function instead and check it up front. Signed-off-by: Jens Axboe

io_uring/cancel: re-grab ctx mutex after finishing wait

2022-12-21T20:31:40Z

If we have a signal pending during cancelations, it'll cause the task_work run to return an error. Since we didn't run task_work, the current task is left in TASK_INTERRUPTIBLE state when we need to re-grab the ctx mutex, and the kernel will rightfully complain about that. Move the lock grabbing for the error cases outside the loop to avoid that issue. Reported-by: syzbot+7df055631cd1be4586fd@syzkaller.appspotmail.com Link: https://lore.kernel.org/io-uring/0000000000003a14a905f05050b0@google.com/ Signed-off-by: Jens Axboe

io_uring: finish waiting before flushing overflow entries

2022-12-21T15:43:53Z

If we have overflow entries being generated after we've done the initial flush in io_cqring_wait(), then we could be flushing them in the main wait loop as well. If that's done after having added ourselves to the cq_wait waitqueue, then the task state can be != TASK_RUNNING when we enter the overflow flush. Check for the need to overflow flush, and finish our wait cycle first if we have to do so. Reported-and-tested-by: syzbot+cf6ea1d6bb30a4ce10b2@syzkaller.appspotmail.com Link: https://lore.kernel.org/io-uring/000000000000cb143a05f04eee15@google.com/ Signed-off-by: Jens Axboe

io_uring/net: fix cleanup after recycle

2022-12-19T15:28:28Z

Don't access io_async_msghdr io_netmsg_recycle(), it may be reallocated. Cc: stable@vger.kernel.org Fixes: 9bb66906f23e5 ("io_uring: support multishot in recvmsg") Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/9e326f4ad4046ddadf15bf34bf3fa58c6372f6b5.1671461985.git.asml.silence@gmail.com Signed-off-by: Jens Axboe

io_uring/net: ensure compat import handlers clear free_iov

2022-12-19T14:35:16Z

If we're not allocating the vectors because the count is below UIO_FASTIOV, we still do need to properly clear ->free_iov to prevent an erronous free of on-stack data. Reported-by: Jiri Slaby Fixes: 4c17a496a7a0 ("io_uring/net: fix cleanup double free free_iov init") Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe

io_uring: include task_work run after scheduling in wait for events

2022-12-18T03:35:54Z

It's quite possible that we got woken up because task_work was queued, and we need to process this task_work to generate the events waited for. If we return to the wait loop without running task_work, we'll end up adding the task to the waitqueue again, only to call io_cqring_wait_schedule() again which will run the task_work. This is less efficient than it could be, as it requires adding to the cq_wait queue again. It also triggers the wakeup path for completions as cq_wait is now non-empty with the task itself, and it'll require another lock grab and deletion to remove ourselves from the waitqueue. Signed-off-by: Jens Axboe