Unverified Commit 7a7ce8b3 authored by Christian Brauner's avatar Christian Brauner
Browse files

input: remove f_version abuse 

f_version is removed from struct file. Make input stop abusing f_version
for stashing information for poll. Move the input state counter into
input_seq_state and allocate it via seq_private_open() and free via
seq_release_private().

Link: https://lore.kernel.org/r/20240830-vfs-file-f_version-v1-12-6d3e4816aa7b@kernel.org


Reviewed-by: default avatarJan Kara <jack@suse.cz>
Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 4f05ee2f

drivers/input/input.c

+22 −25
Original line number Diff line number Diff line
@@ -1079,33 +1079,31 @@ static inline void input_wakeup_procfs_readers(void) 
	wake_up(&input_devices_poll_wait);

}



struct input_seq_state {

	unsigned short pos;

	bool mutex_acquired;

	int input_devices_state;

};



static __poll_t input_proc_devices_poll(struct file *file, poll_table *wait)

{

	struct seq_file *seq = file->private_data;

	struct input_seq_state *state = seq->private;



	poll_wait(file, &input_devices_poll_wait, wait);

	if (file->f_version != input_devices_state) {

		file->f_version = input_devices_state;

	if (state->input_devices_state != input_devices_state) {

		state->input_devices_state = input_devices_state;

		return EPOLLIN | EPOLLRDNORM;

	}



	return 0;

}



union input_seq_state {

	struct {

		unsigned short pos;

		bool mutex_acquired;

	};

	void *p;

};



static void *input_devices_seq_start(struct seq_file *seq, loff_t *pos)

{

	union input_seq_state *state = (union input_seq_state *)&seq->private;

	struct input_seq_state *state = seq->private;

	int error;



	/* We need to fit into seq->private pointer */

	BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private));



	error = mutex_lock_interruptible(&input_mutex);

	if (error) {

		state->mutex_acquired = false;
@@ -1124,7 +1122,7 @@ static void *input_devices_seq_next(struct seq_file *seq, void *v, loff_t *pos) 


static void input_seq_stop(struct seq_file *seq, void *v)

{

	union input_seq_state *state = (union input_seq_state *)&seq->private;

	struct input_seq_state *state = seq->private;



	if (state->mutex_acquired)

		mutex_unlock(&input_mutex);
@@ -1210,7 +1208,8 @@ static const struct seq_operations input_devices_seq_ops = { 


static int input_proc_devices_open(struct inode *inode, struct file *file)

{

	return seq_open(file, &input_devices_seq_ops);

	return seq_open_private(file, &input_devices_seq_ops,

				sizeof(struct input_seq_state));

}



static const struct proc_ops input_devices_proc_ops = {
@@ -1218,17 +1217,14 @@ static const struct proc_ops input_devices_proc_ops = { 
	.proc_poll	= input_proc_devices_poll,

	.proc_read	= seq_read,

	.proc_lseek	= seq_lseek,

	.proc_release	= seq_release,

	.proc_release	= seq_release_private,

};



static void *input_handlers_seq_start(struct seq_file *seq, loff_t *pos)

{

	union input_seq_state *state = (union input_seq_state *)&seq->private;

	struct input_seq_state *state = seq->private;

	int error;



	/* We need to fit into seq->private pointer */

	BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private));



	error = mutex_lock_interruptible(&input_mutex);

	if (error) {

		state->mutex_acquired = false;
@@ -1243,7 +1239,7 @@ static void *input_handlers_seq_start(struct seq_file *seq, loff_t *pos) 


static void *input_handlers_seq_next(struct seq_file *seq, void *v, loff_t *pos)

{

	union input_seq_state *state = (union input_seq_state *)&seq->private;

	struct input_seq_state *state = seq->private;



	state->pos = *pos + 1;

	return seq_list_next(v, &input_handler_list, pos);
@@ -1252,7 +1248,7 @@ static void *input_handlers_seq_next(struct seq_file *seq, void *v, loff_t *pos) 
static int input_handlers_seq_show(struct seq_file *seq, void *v)

{

	struct input_handler *handler = container_of(v, struct input_handler, node);

	union input_seq_state *state = (union input_seq_state *)&seq->private;

	struct input_seq_state *state = seq->private;



	seq_printf(seq, "N: Number=%u Name=%s", state->pos, handler->name);

	if (handler->filter)
@@ -1273,14 +1269,15 @@ static const struct seq_operations input_handlers_seq_ops = { 


static int input_proc_handlers_open(struct inode *inode, struct file *file)

{

	return seq_open(file, &input_handlers_seq_ops);

	return seq_open_private(file, &input_handlers_seq_ops,

				sizeof(struct input_seq_state));

}



static const struct proc_ops input_handlers_proc_ops = {

	.proc_open	= input_proc_handlers_open,

	.proc_read	= seq_read,

	.proc_lseek	= seq_lseek,

	.proc_release	= seq_release,

	.proc_release	= seq_release_private,

};



static int __init input_proc_init(void)