Commit 56bf8898 authored by Pavel Begunkov's avatar Pavel Begunkov Committed by openeuler-sync-bot
Browse files

io_uring: disable polling pollfree files 

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=v5.10.162&id=28d8d2737e82fc29ff9e788597661abecc7f7994



--------------------------------

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: 221c5eb2 ("io_uring: add support for IORING_OP_POLL")
Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>

conflicts:
  include/linux/fs.h

Signed-off-by: default avatarLi Lingfeng <lilingfeng3@huawei.com>
Reviewed-by: default avatarZhang Yi <yi.zhang@huawei.com>
Signed-off-by: default avatarJialin Zhang <zhangjialin11@huawei.com>
(cherry picked from commit b3851214)
parent 3baaef8c

drivers/android/binder.c

+1 −0
Original line number Diff line number Diff line
@@ -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)

fs/io_uring.c

+5 −0
Original line number Diff line number Diff line
@@ -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;

fs/signalfd.c

+1 −0
Original line number Diff line number Diff line
@@ -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)

include/linux/fs.h

+1 −0
Original line number Diff line number Diff line
@@ -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)