On Sat, 12 Apr 2025 21:33:48 +0800
Menglong Dong <menglong8.dong@xxxxxxxxx> wrote:
> The max ftrace hash bits is made fls(32) in register_ftrace_direct(),
> which seems illogical, and it seems to be a spelling mistake.
>
> Just fix it.
>
> (Do I misunderstand something?)
I think the logic is incorrect and this patch doesn't fix it.
>
> Fixes: d05cb470663a ("ftrace: Fix modification of direct_function hash while in use")
> Signed-off-by: Menglong Dong <dongml2@xxxxxxxxxxxxxxx>
> ---
> kernel/trace/ftrace.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
> index 1a48aedb5255..7697605a41e6 100644
> --- a/kernel/trace/ftrace.c
> +++ b/kernel/trace/ftrace.c
> @@ -5914,7 +5914,7 @@ 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)
> + if (size < 32)
> size = 32;
> new_hash = alloc_ftrace_hash(fls(size));
> if (!new_hash)
The above probably should be:
size = hash->count + direct_functions->count
size = fls(size);
if (size > FTRACE_HASH_MAX_BITS)
size = FTRACE_HASH_MAX_BITS;
new_hash = alloc_ftrace_hash(size);
-- Steve
