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| author | Pavel Begunkov <asml.silence@gmail.com> | 2022-09-01 16:16:10 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-09-05 10:28:58 +0200 |
| commit | 28d8d2737e82fc29ff9e788597661abecc7f7994 (patch) | |
| tree | 45cf68550ff4cf406324ec448480790ce84d294c | |
| parent | 744b0d3080709a172f0408aedabd1cedd24c2ee6 (diff) | |
| download | linux-stable-28d8d2737e82fc29ff9e788597661abecc7f7994.tar.gz linux-stable-28d8d2737e82fc29ff9e788597661abecc7f7994.tar.bz2 linux-stable-28d8d2737e82fc29ff9e788597661abecc7f7994.zip | |
io_uring: disable polling pollfree files
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>
| -rw-r--r-- | drivers/android/binder.c | 1 | ||||
| -rw-r--r-- | fs/io_uring.c | 5 | ||||
| -rw-r--r-- | fs/signalfd.c | 1 | ||||
| -rw-r--r-- | include/linux/fs.h | 1 |
4 files changed, 8 insertions, 0 deletions
diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 366b12405708..a5d5247c4f3e 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -6069,6 +6069,7 @@ 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 a952288b2ab8..9654b60a06a5 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -5198,6 +5198,11 @@ 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 42d246a94228..c8f887641878 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1859,6 +1859,7 @@ 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; } __randomize_layout; struct inode_operations { |