From: Marco Elver elver@google.com

Commit 56348560d495 ("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: 56348560d495 ("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 --- kernel/kcsan/core.c | 2 -- kernel/kcsan/debugfs.c | 4 +++- kernel/kcsan/kcsan.h | 5 ----- 3 files changed, 3 insertions(+), 8 deletions(-)

diff --git a/kernel/kcsan/core.c b/kernel/kcsan/core.c index 3bf98db..23e7acb 100644 --- a/kernel/kcsan/core.c +++ b/kernel/kcsan/core.c @@ -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();

diff --git a/kernel/kcsan/debugfs.c b/kernel/kcsan/debugfs.c index 3c8093a..209ad8d 100644 --- a/kernel/kcsan/debugfs.c +++ b/kernel/kcsan/debugfs.c @@ -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); diff --git a/kernel/kcsan/kcsan.h b/kernel/kcsan/kcsan.h index 8d4bf34..87ccdb3 100644 --- a/kernel/kcsan/kcsan.h +++ b/kernel/kcsan/kcsan.h @@ -31,11 +31,6 @@ 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. */