From 92f1d3b40179b15630d72e2c6e4e25a899b67ba9 Mon Sep 17 00:00:00 2001 From: Menglong Dong Date: Sun, 13 Apr 2025 09:44:44 +0800 Subject: [PATCH] ftrace: fix incorrect hash size in register_ftrace_direct() 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 Acked-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google) --- 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; -- 2.49.0