Commit e36299ef authored Mar 03, 2021 by Marco Elver Committed by Paul E. McKenney Mar 08, 2021

kcsan, debugfs: Move debugfs file creation out of early init



Commit 56348560 ("debugfs: do not attempt to create a new file
before the filesystem is initalized") forbids creating new debugfs files
until debugfs is fully initialized.  This means that KCSAN's debugfs
file creation, which happened at the end of __init(), no longer works.
And was apparently never supposed to work!

However, there is no reason to create KCSAN's debugfs file so early.
This commit therefore moves its creation to a late_initcall() callback.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: stable <stable@vger.kernel.org>
Fixes: 56348560 ("debugfs: do not attempt to create a new file before the filesystem is initalized")
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

parent a38fd874

kernel/kcsan/core.c

+0 −2

Original line number	Diff line number	Diff line
		@@ -639,8 +639,6 @@ void __init kcsan_init(void)

		BUG_ON(!in_task());

		kcsan_debugfs_init();

		for_each_possible_cpu(cpu)
		per_cpu(kcsan_rand_state, cpu) = (u32)get_cycles();

kernel/kcsan/debugfs.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -261,7 +261,9 @@ static const struct file_operations debugfs_ops =
		.release = single_release
		};

		void __init kcsan_debugfs_init(void)
		static void __init kcsan_debugfs_init(void)
		{
		debugfs_create_file("kcsan", 0644, NULL, NULL, &debugfs_ops);
		}

		late_initcall(kcsan_debugfs_init);

kernel/kcsan/kcsan.h

+0 −5

Original line number	Diff line number	Diff line
		@@ -30,11 +30,6 @@ extern bool kcsan_enabled;
		void kcsan_save_irqtrace(struct task_struct *task);
		void kcsan_restore_irqtrace(struct task_struct *task);

		/*
		* Initialize debugfs file.
		*/
		void kcsan_debugfs_init(void);

		/*
		* Statistics counters displayed via debugfs; should only be modified in
		* slow-paths.