[PATCH] rtlwifi: rtl8192de: Fix initialization of place in _rtl92c_phy_get_rightchnlplace()

[PATCH] rtlwifi: rtl8192de: Fix initialization of place in _rtl92c_phy_get_rightchnlplace()

[Nathan Chancellor]

Clang warns:

drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c:901:6: warning:
variable 'place' is used uninitialized whenever 'if' condition is false
[-Wsometimes-uninitialized]
        if (chnl > 14) {
            ^~~~~~~~~
drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c:909:9: note:
uninitialized use occurs here
        return place;
               ^~~~~
drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c:901:2: note: remove
the 'if' if its condition is always true
        if (chnl > 14) {
        ^~~~~~~~~~~~~~~
drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c:899:10: note:
initialize the variable 'place' to silence this warning
        u8 place;
                ^
                 = '\0'
1 warning generated.

Commit 369956ae5720 ("rtlwifi: rtl8192de: Remove redundant variable
initializations") removed the initialization of place but it appears
that this removal was in the wrong function.

_rtl92c_phy_get_rightchnlplace() returns place's value at the end of the
function so now if the if statement is false, place never gets
initialized. Add that initialization back to address the warning.

place's initialization is not necessary in
rtl92d_get_rightchnlplace_for_iqk() as place is only used within the if
statement so it can be removed, which is likely what was intended in the
first place.

Fixes: 369956ae5720 ("rtlwifi: rtl8192de: Remove redundant variable initializations")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
 drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c b/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c
index 8ae69d914312..9b83c710c9b8 100644
--- a/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c
+++ b/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c
@@ -896,7 +896,7 @@ static void _rtl92d_ccxpower_index_check(struct ieee80211_hw *hw,
 
 static u8 _rtl92c_phy_get_rightchnlplace(u8 chnl)
 {
-	u8 place;
+	u8 place = chnl;
 
 	if (chnl > 14) {
 		for (place = 14; place < sizeof(channel5g); place++) {
@@ -1363,7 +1363,7 @@ static void _rtl92d_phy_switch_rf_setting(struct ieee80211_hw *hw, u8 channel)
 
 u8 rtl92d_get_rightchnlplace_for_iqk(u8 chnl)
 {
-	u8 place = chnl;
+	u8 place;
 
 	if (chnl > 14) {
 		for (place = 14; place < sizeof(channel_all); place++) {

base-commit: 609c1308fbc6446fd6d8fec42b80e157768a5362
-- 
2.33.0

RE: [PATCH] rtlwifi: rtl8192de: Fix initialization of place in _rtl92c_phy_get_rightchnlplace()

[Pkshih]

> -----Original Message-----
> From: Nathan Chancellor [mailto:nathan@kernel.org]
> Sent: Tuesday, August 24, 2021 6:20 AM
> To: Pkshih; Kalle Valo
> Cc: Colin Ian King; linux-wireless@vger.kernel.org; netdev@vger.kernel.org;
> linux-kernel@vger.kernel.org; clang-built-linux@googlegroups.com; llvm@lists.linux.dev; Nathan
> Chancellor
> Subject: [PATCH] rtlwifi: rtl8192de: Fix initialization of place in _rtl92c_phy_get_rightchnlplace()
> 
> Clang warns:
> 
> drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c:901:6: warning:
> variable 'place' is used uninitialized whenever 'if' condition is false
> [-Wsometimes-uninitialized]
>         if (chnl > 14) {
>             ^~~~~~~~~
> drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c:909:9: note:
> uninitialized use occurs here
>         return place;
>                ^~~~~
> drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c:901:2: note: remove
> the 'if' if its condition is always true
>         if (chnl > 14) {
>         ^~~~~~~~~~~~~~~
> drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c:899:10: note:
> initialize the variable 'place' to silence this warning
>         u8 place;
>                 ^
>                  = '\0'
> 1 warning generated.
> 
> Commit 369956ae5720 ("rtlwifi: rtl8192de: Remove redundant variable
> initializations") removed the initialization of place but it appears
> that this removal was in the wrong function.

Somehow, I also look into wrong function.
Thanks for the catch.

> 
> _rtl92c_phy_get_rightchnlplace() returns place's value at the end of the
> function so now if the if statement is false, place never gets
> initialized. Add that initialization back to address the warning.
> 
> place's initialization is not necessary in
> rtl92d_get_rightchnlplace_for_iqk() as place is only used within the if
> statement so it can be removed, which is likely what was intended in the
> first place.
> 
> Fixes: 369956ae5720 ("rtlwifi: rtl8192de: Remove redundant variable initializations")
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>

Acked-by: Ping-Ke Shih <pkshih@realtek.com>

> ---
>  drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c
> b/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c
> index 8ae69d914312..9b83c710c9b8 100644
> --- a/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c
> +++ b/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c
> @@ -896,7 +896,7 @@ static void _rtl92d_ccxpower_index_check(struct ieee80211_hw *hw,
> 
>  static u8 _rtl92c_phy_get_rightchnlplace(u8 chnl)
>  {
> -	u8 place;
> +	u8 place = chnl;
> 
>  	if (chnl > 14) {
>  		for (place = 14; place < sizeof(channel5g); place++) {
> @@ -1363,7 +1363,7 @@ static void _rtl92d_phy_switch_rf_setting(struct ieee80211_hw *hw, u8 channel)
> 
>  u8 rtl92d_get_rightchnlplace_for_iqk(u8 chnl)
>  {
> -	u8 place = chnl;
> +	u8 place;
> 
>  	if (chnl > 14) {
>  		for (place = 14; place < sizeof(channel_all); place++) {
> 
> base-commit: 609c1308fbc6446fd6d8fec42b80e157768a5362
> --
> 2.33.0

Re: [PATCH] rtlwifi: rtl8192de: Fix initialization of place in _rtl92c_phy_get_rightchnlplace()

[Kees Cook]

On Mon, Aug 23, 2021 at 03:20:14PM -0700, Nathan Chancellor wrote:
> Clang warns:
> 
> drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c:901:6: warning:
> variable 'place' is used uninitialized whenever 'if' condition is false
> [-Wsometimes-uninitialized]
>         if (chnl > 14) {
>             ^~~~~~~~~
> drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c:909:9: note:
> uninitialized use occurs here
>         return place;
>                ^~~~~
> drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c:901:2: note: remove
> the 'if' if its condition is always true
>         if (chnl > 14) {
>         ^~~~~~~~~~~~~~~
> drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c:899:10: note:
> initialize the variable 'place' to silence this warning
>         u8 place;
>                 ^
>                  = '\0'
> 1 warning generated.
> 
> Commit 369956ae5720 ("rtlwifi: rtl8192de: Remove redundant variable
> initializations") removed the initialization of place but it appears
> that this removal was in the wrong function.
> 
> _rtl92c_phy_get_rightchnlplace() returns place's value at the end of the
> function so now if the if statement is false, place never gets
> initialized. Add that initialization back to address the warning.
> 
> place's initialization is not necessary in
> rtl92d_get_rightchnlplace_for_iqk() as place is only used within the if
> statement so it can be removed, which is likely what was intended in the
> first place.
> 
> Fixes: 369956ae5720 ("rtlwifi: rtl8192de: Remove redundant variable initializations")
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>

Thanks, I tripped over this too.

Reviewed-by: Kees Cook <keescook@chromium.org>

-Kees

> ---
>  drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c b/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c
> index 8ae69d914312..9b83c710c9b8 100644
> --- a/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c
> +++ b/drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c
> @@ -896,7 +896,7 @@ static void _rtl92d_ccxpower_index_check(struct ieee80211_hw *hw,
>  
>  static u8 _rtl92c_phy_get_rightchnlplace(u8 chnl)
>  {
> -	u8 place;
> +	u8 place = chnl;
>  
>  	if (chnl > 14) {
>  		for (place = 14; place < sizeof(channel5g); place++) {
> @@ -1363,7 +1363,7 @@ static void _rtl92d_phy_switch_rf_setting(struct ieee80211_hw *hw, u8 channel)
>  
>  u8 rtl92d_get_rightchnlplace_for_iqk(u8 chnl)
>  {
> -	u8 place = chnl;
> +	u8 place;
>  
>  	if (chnl > 14) {
>  		for (place = 14; place < sizeof(channel_all); place++) {
> 
> base-commit: 609c1308fbc6446fd6d8fec42b80e157768a5362
> -- 
> 2.33.0
> 

-- 
Kees Cook

Re: [PATCH] rtlwifi: rtl8192de: Fix initialization of place in _rtl92c_phy_get_rightchnlplace()

[Kalle Valo]

Nathan Chancellor <nathan@kernel.org> wrote:

> Clang warns:
> 
> drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c:901:6: warning:
> variable 'place' is used uninitialized whenever 'if' condition is false
> [-Wsometimes-uninitialized]
>         if (chnl > 14) {
>             ^~~~~~~~~
> drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c:909:9: note:
> uninitialized use occurs here
>         return place;
>                ^~~~~
> drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c:901:2: note: remove
> the 'if' if its condition is always true
>         if (chnl > 14) {
>         ^~~~~~~~~~~~~~~
> drivers/net/wireless/realtek/rtlwifi/rtl8192de/phy.c:899:10: note:
> initialize the variable 'place' to silence this warning
>         u8 place;
>                 ^
>                  = '\0'
> 1 warning generated.
> 
> Commit 369956ae5720 ("rtlwifi: rtl8192de: Remove redundant variable
> initializations") removed the initialization of place but it appears
> that this removal was in the wrong function.
> 
> _rtl92c_phy_get_rightchnlplace() returns place's value at the end of the
> function so now if the if statement is false, place never gets
> initialized. Add that initialization back to address the warning.
> 
> place's initialization is not necessary in
> rtl92d_get_rightchnlplace_for_iqk() as place is only used within the if
> statement so it can be removed, which is likely what was intended in the
> first place.
> 
> Fixes: 369956ae5720 ("rtlwifi: rtl8192de: Remove redundant variable initializations")
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>
> Acked-by: Ping-Ke Shih <pkshih@realtek.com>
> Reviewed-by: Kees Cook <keescook@chromium.org>

Patch applied to wireless-drivers-next.git, thanks.

533ccdae76fa rtlwifi: rtl8192de: Fix initialization of place in _rtl92c_phy_get_rightchnlplace()

-- 
https://patchwork.kernel.org/project/linux-wireless/patch/20210823222014.764557-1-nathan@kernel.org/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches