Commit bee43904 authored by Stanislav Kinsburskii's avatar Stanislav Kinsburskii Committed by Petr Mladek
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printk: Remove obsoleted check for non-existent "user" object 



The original check for non-null "user" object was introduced by commit
e11fea92 ("kmsg: export printk records to the /dev/kmsg interface")
when "user" could be NULL if /dev/ksmg was opened for writing.

Subsequent change 750afe7b ("printk: add kernel parameter to control
writes to /dev/kmsg") made "user" context required for files opened for
write, but didn't remove now redundant checks for it to be non-NULL.

This patch removes the dead code while preserving the current logic.

Signed-off-by: default avatarStanislav Kinsburskii <stanislav.kinsburski@gmail.com>
CC: Petr Mladek <pmladek@suse.com>
CC: Sergey Senozhatsky <senozhatsky@chromium.org>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: John Ogness <john.ogness@linutronix.de>
CC: linux-kernel@vger.kernel.org
Reviewed-by: default avatarSergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: default avatarPetr Mladek <pmladek@suse.com>
Signed-off-by: default avatarPetr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/167929571877.2810.9926967619100618792.stgit@skinsburskii.localdomain
parent 48e1a66f

kernel/printk/printk.c

+1 −12
Original line number Diff line number Diff line
@@ -730,7 +730,7 @@ static ssize_t devkmsg_write(struct kiocb *iocb, struct iov_iter *from) 
	size_t len = iov_iter_count(from);

	ssize_t ret = len;



	if (!user || len > PRINTKRB_RECORD_MAX)

	if (len > PRINTKRB_RECORD_MAX)

		return -EINVAL;



	/* Ignore when user logging is disabled. */
@@ -792,9 +792,6 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf, 
	};

	ssize_t ret;



	if (!user)

		return -EBADF;



	ret = mutex_lock_interruptible(&user->lock);

	if (ret)

		return ret;
@@ -859,8 +856,6 @@ static loff_t devkmsg_llseek(struct file *file, loff_t offset, int whence) 
	struct devkmsg_user *user = file->private_data;

	loff_t ret = 0;



	if (!user)

		return -EBADF;

	if (offset)

		return -ESPIPE;
@@ -893,9 +888,6 @@ static __poll_t devkmsg_poll(struct file *file, poll_table *wait) 
	struct printk_info info;

	__poll_t ret = 0;



	if (!user)

		return EPOLLERR|EPOLLNVAL;



	poll_wait(file, &log_wait, wait);



	if (prb_read_valid_info(prb, atomic64_read(&user->seq), &info, NULL)) {
@@ -944,9 +936,6 @@ static int devkmsg_release(struct inode *inode, struct file *file) 
{

	struct devkmsg_user *user = file->private_data;



	if (!user)

		return 0;



	ratelimit_state_exit(&user->rs);



	mutex_destroy(&user->lock);