[PATCH] staging: ks7010: honor 'const' qualifier

[PATCH] staging: ks7010: honor 'const' qualifier

[Arnd Bergmann]

The recently-added ks7010 driver produces an annoying build warning:

drivers/staging/ks7010/ks7010_config.c: In function 'ks_wlan_read_config_file':
drivers/staging/ks7010/ks7010_config.c:263:8: error: assignment discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers]

The problem here is that it assigns the firmware data to a non-const
variable, and then goes on to modify it, which is clearly not the intended
use case.

The only modification is to set the last byte to '\0', and as far as
I can tell, this modification is unnecessary, as the parser always compares
against the end pointer, rather than relying on zero-termination.

This patch therefore removes the modification of the const data and marks
all the pointers 'const to avoid the warning.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/staging/ks7010/ks7010_config.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/staging/ks7010/ks7010_config.c b/drivers/staging/ks7010/ks7010_config.c
index 4b495cbef481..945ff6c7f419 100644
--- a/drivers/staging/ks7010/ks7010_config.c
+++ b/drivers/staging/ks7010/ks7010_config.c
@@ -16,7 +16,7 @@ static int wep_type;
 
 static
 void analyze_character_wep_key(struct ks_wlan_parameter *param,
-			       int wep_key_index, char *value)
+			       int wep_key_index, const char *value)
 {
 	int i;
 	unsigned char wep_key[26], key_length;
@@ -39,7 +39,7 @@ void analyze_character_wep_key(struct ks_wlan_parameter *param,
 
 static
 void analyze_hex_wep_key(struct ks_wlan_parameter *param, int wep_key_index,
-			 char *value)
+			 const char *value)
 {
 	unsigned char wep_end[26], i, j, key_length;
 
@@ -93,7 +93,7 @@ void analyze_hex_wep_key(struct ks_wlan_parameter *param, int wep_key_index,
 }
 
 static
-int rate_set_configuration(struct ks_wlan_private *priv, char *value)
+int rate_set_configuration(struct ks_wlan_private *priv, const char *value)
 {
 	int rc = 0;
 
@@ -204,9 +204,10 @@ int ks_wlan_read_config_file(struct ks_wlan_private *priv)
 
 	const struct firmware *fw_entry;
 	struct device *dev = NULL;
-	char cfg_file[] = CFG_FILE;
-	char *cur_p, *end_p;
-	char wk_buff[256], *wk_p;
+	const char cfg_file[] = CFG_FILE;
+	const char *cur_p, *end_p;
+	char wk_buff[256];
+	const char *wk_p;
 
 	/* Initialize Variable */
 	priv->reg.operation_mode = MODE_INFRASTRUCTURE;	/* Infrastructure */
@@ -262,7 +263,6 @@ int ks_wlan_read_config_file(struct ks_wlan_private *priv)
 		fw_entry->size);
 	cur_p = fw_entry->data;
 	end_p = cur_p + fw_entry->size;
-	*end_p = '\0';
 
 	while (cur_p < end_p) {
 		int i, j, len;
-- 
2.9.0

Re: [PATCH] staging: ks7010: honor 'const' qualifier

[Wolfram Sang]

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On Wed, Jun 15, 2016 at 11:53:11PM +0200, Arnd Bergmann wrote:
> The recently-added ks7010 driver produces an annoying build warning:
> 
> drivers/staging/ks7010/ks7010_config.c: In function 'ks_wlan_read_config_file':
> drivers/staging/ks7010/ks7010_config.c:263:8: error: assignment discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers]
> 
> The problem here is that it assigns the firmware data to a non-const
> variable, and then goes on to modify it, which is clearly not the intended
> use case.
> 
> The only modification is to set the last byte to '\0', and as far as
> I can tell, this modification is unnecessary, as the parser always compares
> against the end pointer, rather than relying on zero-termination.
> 
> This patch therefore removes the modification of the const data and marks
> all the pointers 'const to avoid the warning.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Thanks! I'll send in a second a patch, though, which removes the config
file handling completely.

   Wolfram


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Re: [PATCH] staging: ks7010: honor 'const' qualifier

[Arnd Bergmann]

On Friday, June 17, 2016 10:26:38 AM CEST Wolfram Sang wrote:
> On Wed, Jun 15, 2016 at 11:53:11PM +0200, Arnd Bergmann wrote:
> > The recently-added ks7010 driver produces an annoying build warning:
> > 
> > drivers/staging/ks7010/ks7010_config.c: In function 'ks_wlan_read_config_file':
> > drivers/staging/ks7010/ks7010_config.c:263:8: error: assignment discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers]
> > 
> > The problem here is that it assigns the firmware data to a non-const
> > variable, and then goes on to modify it, which is clearly not the intended
> > use case.
> > 
> > The only modification is to set the last byte to '\0', and as far as
> > I can tell, this modification is unnecessary, as the parser always compares
> > against the end pointer, rather than relying on zero-termination.
> > 
> > This patch therefore removes the modification of the const data and marks
> > all the pointers 'const to avoid the warning.
> > 
> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> 
> Thanks! I'll send in a second a patch, though, which removes the config
> file handling completely.

Ok, perfect!

	Arnd