eventfd: provide a eventfd_signal_mask() helper
stable inclusion from stable-v5.10.162 commit 4ef66581d7fdbd9bfe0b399c1a2479f8ea5cfdf0 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I7P7OH Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=4ef66581d7fdbd9bfe0b399c1a2479f8ea5cfdf0 -------------------------------- [ Upstream commit 03e02acd ] This is identical to eventfd_signal(), but it allows the caller to pass in a mask to be used for the poll wakeup key. The use case is avoiding repeated multishot triggers if we have a dependency between eventfd and io_uring. If we setup an eventfd context and register that as the io_uring eventfd, and at the same time queue a multishot poll request for the eventfd context, then any CQE posted will repeatedly trigger the multishot request until it terminates when the CQ ring overflows. In preparation for io_uring detecting this circular dependency, add the mentioned helper so that io_uring can pass in EPOLL_URING as part of the poll wakeup key. Cc: stable@vger.kernel.org # 6.0 [axboe: fold in !CONFIG_EVENTFD fix from Zhang Qilong] Signed-off-by: NJens Axboe <axboe@kernel.dk> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Nsanglipeng <sanglipeng1@jd.com>
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