[PATCH v2] staging: rtl8192u: Constufy ieee80211_qos_parameters structure

[PATCH v2] staging: rtl8192u: Constufy ieee80211_qos_parameters structure

[Gargi Sharma]

Declare def_qos_parameters instance of the ieee80211_qos_parameters
structure as it is only passed src parameter to the function memcpy.
The fields of def_qos_parameters structure are never modified and
hence it can be declared as const.

Coccinelle Script:

@r1 disable optional_qualifier@
identifier i;
position p;
@@

static struct ieee80211_qos_parameters i@p ={...};

@ok1@
identifier r1.i;
position p;
expression e1,e2;
@@
memcpy(e1,&i@p,e2)

@bad@
position p!={r1.p,ok1.p};
identifier r1.i;
@@
i@p

@depends on !bad disable optional_qualifier@
identifier r1.i;
@@
static
+const
struct ieee80211_qos_parameters i={...};

Signed-off-by: Gargi Sharma <gs051095@gmail.com>
---
Changes in v2:
	- Improved the coccinelle script to check for safety of the
	  modification.
	- Improved the commit message.
---
 drivers/staging/rtl8192u/r8192U_core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/rtl8192u/r8192U_core.c b/drivers/staging/rtl8192u/r8192U_core.c
index b631990..bbb5f58 100644
--- a/drivers/staging/rtl8192u/r8192U_core.c
+++ b/drivers/staging/rtl8192u/r8192U_core.c
@@ -1814,7 +1814,7 @@ static void rtl8192_link_change(struct net_device *dev)
 	}
 }
 
-static struct ieee80211_qos_parameters def_qos_parameters = {
+static const struct ieee80211_qos_parameters def_qos_parameters = {
 	{cpu_to_le16(3), cpu_to_le16(3), cpu_to_le16(3), cpu_to_le16(3)},
 	{cpu_to_le16(7), cpu_to_le16(7), cpu_to_le16(7), cpu_to_le16(7)},
 	{2, 2, 2, 2},/* aifs */
-- 
2.7.4

Re: [PATCH v2] staging: rtl8192u: Constufy ieee80211_qos_parameters structure

[Gargi Sharma]

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On Thu, Mar 2, 2017 at 10:49 AM, Gargi Sharma <gs051095@gmail.com> wrote:
>
> Declare def_qos_parameters instance of the ieee80211_qos_parameters
> structure as it is only passed src parameter to the function memcpy.
> The fields of def_qos_parameters structure are never modified and
> hence it can be declared as const.
>

The commit message is a bit incorrect here. Please ignore this patch.

thanks and apologies,
gargi

> Coccinelle Script:
>
> @r1 disable optional_qualifier@
> identifier i;
> position p;
> @@
>
> static struct ieee80211_qos_parameters i@p ={...};
>
> @ok1@
> identifier r1.i;
> position p;
> expression e1,e2;
> @@
> memcpy(e1,&i@p,e2)
>
> @bad@
> position p!={r1.p,ok1.p};
> identifier r1.i;
> @@
> i@p
>
> @depends on !bad disable optional_qualifier@
> identifier r1.i;
> @@
> static
> +const
> struct ieee80211_qos_parameters i={...};
>
> Signed-off-by: Gargi Sharma <gs051095@gmail.com>
> ---
> Changes in v2:
>         - Improved the coccinelle script to check for safety of the
>           modification.
>         - Improved the commit message.
> ---
>  drivers/staging/rtl8192u/r8192U_core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/staging/rtl8192u/r8192U_core.c
b/drivers/staging/rtl8192u/r8192U_core.c
> index b631990..bbb5f58 100644
> --- a/drivers/staging/rtl8192u/r8192U_core.c
> +++ b/drivers/staging/rtl8192u/r8192U_core.c
> @@ -1814,7 +1814,7 @@ static void rtl8192_link_change(struct net_device
*dev)
>         }
>  }
>
> -static struct ieee80211_qos_parameters def_qos_parameters = {
> +static const struct ieee80211_qos_parameters def_qos_parameters = {
>         {cpu_to_le16(3), cpu_to_le16(3), cpu_to_le16(3), cpu_to_le16(3)},
>         {cpu_to_le16(7), cpu_to_le16(7), cpu_to_le16(7), cpu_to_le16(7)},
>         {2, 2, 2, 2},/* aifs */
> --
> 2.7.4
>

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