From: Pavel Begunkov <asml.silence@gmail.com> stable inclusion from stable-v5.10.141 commit 28d8d2737e82fc29ff9e788597661abecc7f7994 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I685FC CEV: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=v... -------------------------------- Older kernels lack io_uring POLLFREE handling. As only affected files are signalfd and android binder the safest option would be to disable polling those files via io_uring and hope there are no users. Fixes: 221c5eb233823 ("io_uring: add support for IORING_OP_POLL") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> conflicts: include/linux/fs.h Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com> Reviewed-by: Zhang Yi <yi.zhang@huawei.com> Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com> --- drivers/android/binder.c | 1 + fs/io_uring.c | 5 +++++ fs/signalfd.c | 1 + include/linux/fs.h | 1 + 4 files changed, 8 insertions(+) diff --git a/drivers/android/binder.c b/drivers/android/binder.c index b9985eee8c1b..cfb1393a0891 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -6081,6 +6081,7 @@ const struct file_operations binder_fops = { .open = binder_open, .flush = binder_flush, .release = binder_release, + .may_pollfree = true, }; static int __init init_binder_device(const char *name) diff --git a/fs/io_uring.c b/fs/io_uring.c index 3ccd34f4d134..d730d90798ec 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -5233,6 +5233,11 @@ static __poll_t __io_arm_poll_handler(struct io_kiocb *req, struct io_ring_ctx *ctx = req->ctx; bool cancel = false; + if (req->file->f_op->may_pollfree) { + spin_lock_irq(&ctx->completion_lock); + return -EOPNOTSUPP; + } + INIT_HLIST_NODE(&req->hash_node); io_init_poll_iocb(poll, mask, wake_func); poll->file = req->file; diff --git a/fs/signalfd.c b/fs/signalfd.c index b94fb5f81797..41dc597b78cc 100644 --- a/fs/signalfd.c +++ b/fs/signalfd.c @@ -248,6 +248,7 @@ static const struct file_operations signalfd_fops = { .poll = signalfd_poll, .read = signalfd_read, .llseek = noop_llseek, + .may_pollfree = true, }; static int do_signalfd4(int ufd, sigset_t *mask, int flags) diff --git a/include/linux/fs.h b/include/linux/fs.h index 45ea1243118c..cf0faea8ff6d 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1898,6 +1898,7 @@ struct file_operations { struct file *file_out, loff_t pos_out, loff_t len, unsigned int remap_flags); int (*fadvise)(struct file *, loff_t, loff_t, int); + bool may_pollfree; KABI_RESERVE(1) KABI_RESERVE(2) -- 2.25.1