[for-linus][PATCH 4/7] ftrace: fix incorrect hash size in register_ftrace_direct()

[Steven Rostedt <rostedt@goodmis.org>]

From: Menglong Dong <menglong8.dong@gmail.com>

The maximum of the ftrace hash bits is made fls(32) in
register_ftrace_direct(), which seems illogical. So, we fix it by making
the max hash bits FTRACE_HASH_MAX_BITS instead.

Link: https://lore.kernel.org/20250413014444.36724-1-dongml2@chinatelecom.cn
Fixes: d05cb470663a ("ftrace: Fix modification of direct_function hash while in use")
Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 kernel/trace/ftrace.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 41dcfcf8b40a..61130bb34d6c 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -5964,9 +5964,10 @@ int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr)
 
 	/* Make a copy hash to place the new and the old entries in */
 	size = hash->count + direct_functions->count;
-	if (size > 32)
-		size = 32;
-	new_hash = alloc_ftrace_hash(fls(size));
+	size = fls(size);
+	if (size > FTRACE_HASH_MAX_BITS)
+		size = FTRACE_HASH_MAX_BITS;
+	new_hash = alloc_ftrace_hash(size);
 	if (!new_hash)
 		goto out_unlock;
 
-- 
2.47.2