2019-05-31 17:38:33

by Gustavo A. R. Silva

Subject: [PATCH] i3c: master: Use struct_size() helper

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes, in particular in the
context in which this code is being used.

So, replace the following form:

sizeof(*defslvs) + ((ndevs - 1) * sizeof(struct i3c_ccc_dev_desc))

with:

struct_size(defslvs, slaves, ndevs - 1)

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
drivers/i3c/master.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index b9d2b88928e1..923b04052038 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -924,9 +924,8 @@ int i3c_master_defslvs_locked(struct i3c_master_controller *master)
ndevs++;

defslvs = i3c_ccc_cmd_dest_init(&dest, I3C_BROADCAST_ADDR,
- sizeof(*defslvs) +
- ((ndevs - 1) *
- sizeof(struct i3c_ccc_dev_desc)));
+ struct_size(defslvs, slaves,
+ ndevs - 1));
if (!defslvs)
return -ENOMEM;

--
2.21.0

2019-06-01 08:21:38

by Boris Brezillon

Subject: Re: [PATCH] i3c: master: Use struct_size() helper

On Fri, 31 May 2019 12:35:32 -0500
"Gustavo A. R. Silva" <[email protected]> wrote:

> Make use of the struct_size() helper instead of an open-coded version
> in order to avoid any potential type mistakes, in particular in the
> context in which this code is being used.
>
> So, replace the following form:
>
> sizeof(*defslvs) + ((ndevs - 1) * sizeof(struct i3c_ccc_dev_desc))
>
> with:
>
> struct_size(defslvs, slaves, ndevs - 1)
>
> This code was detected with the help of Coccinelle.
>
> Signed-off-by: Gustavo A. R. Silva <[email protected]>
> ---
> drivers/i3c/master.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
> index b9d2b88928e1..923b04052038 100644
> --- a/drivers/i3c/master.c
> +++ b/drivers/i3c/master.c
> @@ -924,9 +924,8 @@ int i3c_master_defslvs_locked(struct i3c_master_controller *master)
> ndevs++;
>
> defslvs = i3c_ccc_cmd_dest_init(&dest, I3C_BROADCAST_ADDR,
> - sizeof(*defslvs) +
> - ((ndevs - 1) *
> - sizeof(struct i3c_ccc_dev_desc)));
> + struct_size(defslvs, slaves,
> + ndevs - 1));

ndev - 1 should be aligned on the struct_size open parens, or even
better, be put on one line since it seems to fit the 80-chars limit:

defslvs = i3c_ccc_cmd_dest_init(&dest, I3C_BROADCAST_ADDR,
struct_size(defslvs, slaves, ndevs - 1));


> if (!defslvs)
> return -ENOMEM;
>