Re: [PATCH] fs: wipe off the compiler warn

Andrew Morton
2016-07-29T23:02:56Z

On Fri, 29 Jul 2016 22:46:39 +0800 zhongjiang <zhongjiang@huawei.com> wrote:

> From: zhong jiang <zhongjiang@huawei.com>
>
> when compile the kenrel code, I happens to the following warn.
> fs/reiserfs/ibalance.c:1156:2: warning: ___new_insert_key___ may be used
> uninitialized in this function.
> memcpy(new_insert_key_addr, &new_insert_key, KEY_SIZE);
> ^
> The patch just fix it to avoid the warn.
>
> Signed-off-by: zhong jiang <zhongjiang@huawei.com>
> ---
> fs/reiserfs/ibalance.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/reiserfs/ibalance.c b/fs/reiserfs/ibalance.c
> index b751eea..512ce95 100644
> --- a/fs/reiserfs/ibalance.c
> +++ b/fs/reiserfs/ibalance.c
> @@ -818,7 +818,7 @@ int balance_internal(struct tree_balance *tb,
> int order;
> int insert_num, n, k;
> struct buffer_head *S_new;
> - struct item_head new_insert_key;
> + struct item_head uninitialized_var(new_insert_key);
> struct buffer_head *new_insert_ptr = NULL;
> struct item_head *new_insert_key_addr = insert_key;

How do we know this isn't a real bug? It isn't obvious to me that this
warning is a false positive.