Re: [PATCH v2 02/19] coccicheck: detect hashmap_entry.hash assignment

From: Derrick Stolee <stolee@gmail.com>
Date: Sep 25, 2019, 12:44 UTC
Message-ID: <fe53e15f-d78a-5b94-9745-43a521cb0f80@gmail.com>
In-Reply-To: <20190924010324.22619-3-e@80x24.org>

On 9/23/2019 9:03 PM, Eric Wong wrote:

> Assigning hashmap_entry.hash manually leaves hashmap_entry.next
> uninitialized, which can be dangerous once the hashmap_entry is
> inserted into a hashmap.   Detect those assignments and use
> hashmap_entry_init, instead.

I appreciate this future-proofing! Thanks.

Show 30 quoted lines

> 
> Signed-off-by: Eric Wong <e@80x24.org>
> ---
>  contrib/coccinelle/hashmap.cocci | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
>  create mode 100644 contrib/coccinelle/hashmap.cocci
> 
> diff --git a/contrib/coccinelle/hashmap.cocci b/contrib/coccinelle/hashmap.cocci
> new file mode 100644
> index 0000000000..d69e120ccf
> --- /dev/null
> +++ b/contrib/coccinelle/hashmap.cocci
> @@ -0,0 +1,16 @@
> +@ hashmap_entry_init_usage @
> +expression E;
> +struct hashmap_entry HME;
> +@@
> +- HME.hash = E;
> ++ hashmap_entry_init(&HME, E);
> +
> +@@
> +identifier f !~ "^hashmap_entry_init$";
> +expression E;
> +struct hashmap_entry *HMEP;
> +@@
> +  f(...) {<...
> +- HMEP->hash = E;
> ++ hashmap_entry_init(HMEP, E);
> +  ...>}
>