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 breaks KCSAN's debugfs file
creation, which happened at the end of __init().
There is no reason to create the debugfs file during early
initialization. Therefore, move it into a late_initcall() callback.
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx>
Fixes: 56348560d495 ("debugfs: do not attempt to create a new file before the filesystem is initalized")
Signed-off-by: Marco Elver <elver@xxxxxxxxxx>
---
I've marked this for 'stable', since 56348560d495 is also intended for
stable, and would subsequently break KCSAN in all stable kernels where
KCSAN is available (since 5.8).
---
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 8c3867640c21..45c821d4e8bd 100644
--- a/kernel/kcsan/core.c
+++ b/kernel/kcsan/core.c
@@ -644,8 +644,6 @@ 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 c837ce6c52e6..c1dd02f3be8b 100644
--- a/kernel/kcsan/debugfs.c
+++ b/kernel/kcsan/debugfs.c
@@ -266,7 +266,9 @@ 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 594a5dd4842a..9881099d4179 100644
--- a/kernel/kcsan/kcsan.h
+++ b/kernel/kcsan/kcsan.h
@@ -31,11 +31,6 @@ 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.
--
2.30.1.766.gb4fecdf3b7-goog
