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* [PATCH v2] staging: rtl8723bs: remove unused BIT macros definitions
@ 2021-07-30 13:40 Fabio Aiuto
  0 siblings, 0 replies; 3+ messages in thread
From: Fabio Aiuto @ 2021-07-30 13:40 UTC (permalink / raw)
  To: gregkh; +Cc: hdegoede, Larry.Finger, linux-staging, linux-kernel, David Sterba

BIT(x) macro used all over the driver is defined in
include/vsdo/bit.h as

	- #define BIT(nr)	(UL(1) << (nr))

which is safer than the local BIT macros declared.
Local macros shift a signed integer which brings
unespected results. For example:

(unsigned long)(1 << 31) => 0xffffffff80000000

shift.c:

int main() {
        printf("%lx\n", (unsigned long)(1 << 31));
        printf("%lx\n", (unsigned long)(1U << 31));
        return 0;
}

...

$ ./shift
ffffffff80000000
80000000

...

So just remove redundant, less safe macro declarations.

Suggested-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Fabio Aiuto <fabioaiuto83@gmail.com>
---
Changes in v2:
	- Edited changelog

 drivers/staging/rtl8723bs/include/osdep_service.h | 4 ----
 drivers/staging/rtl8723bs/include/wifi.h          | 8 --------
 2 files changed, 12 deletions(-)

diff --git a/drivers/staging/rtl8723bs/include/osdep_service.h b/drivers/staging/rtl8723bs/include/osdep_service.h
index b49838c7e457..bde415db4114 100644
--- a/drivers/staging/rtl8723bs/include/osdep_service.h
+++ b/drivers/staging/rtl8723bs/include/osdep_service.h
@@ -14,10 +14,6 @@
 
 #include <osdep_service_linux.h>
 
-#ifndef BIT
-	#define BIT(x)	(1 << (x))
-#endif
-
 #define BIT0	0x00000001
 #define BIT1	0x00000002
 #define BIT2	0x00000004
diff --git a/drivers/staging/rtl8723bs/include/wifi.h b/drivers/staging/rtl8723bs/include/wifi.h
index 0bd7b662b972..f03e26818d45 100644
--- a/drivers/staging/rtl8723bs/include/wifi.h
+++ b/drivers/staging/rtl8723bs/include/wifi.h
@@ -7,14 +7,6 @@
 #ifndef _WIFI_H_
 #define _WIFI_H_
 
-
-#ifdef BIT
-/* error	"BIT define occurred earlier elsewhere!\n" */
-#undef BIT
-#endif
-#define BIT(x)	(1 << (x))
-
-
 #define WLAN_ETHHDR_LEN		14
 #define WLAN_ETHADDR_LEN	6
 #define WLAN_IEEE_OUI_LEN	3
-- 
2.20.1


^ permalink raw reply	[flat|nested] 3+ messages in thread
* [PATCH v2] staging: rtl8723bs: remove unused BIT macros definitions
@ 2021-07-30 13:39 Fabio Aiuto
  2021-07-30 13:42 ` Fabio Aiuto
  0 siblings, 1 reply; 3+ messages in thread
From: Fabio Aiuto @ 2021-07-30 13:39 UTC (permalink / raw)
  To: fabioaiuto83
  Cc: hdegoede, Larry.Finger, linux-staging, linux-kernel, David Sterba

BIT(x) macro used all over the driver is defined in
include/vsdo/bit.h as

	- #define BIT(nr)	(UL(1) << (nr))

which is safer than the local BIT macros declared.
Local macros shift a signed integer which brings
unespected results. For example:

(unsigned long)(1 << 31) => 0xffffffff80000000

shift.c:

int main() {
        printf("%lx\n", (unsigned long)(1 << 31));
        printf("%lx\n", (unsigned long)(1U << 31));
        return 0;
}

...

$ ./shift
ffffffff80000000
80000000

...

So just remove redundant, less safe macro declarations.

Suggested-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Fabio Aiuto <fabioaiuto83@gmail.com>
---
Changes in v2:
	- edited changelog

 drivers/staging/rtl8723bs/include/osdep_service.h | 4 ----
 drivers/staging/rtl8723bs/include/wifi.h          | 8 --------
 2 files changed, 12 deletions(-)

diff --git a/drivers/staging/rtl8723bs/include/osdep_service.h b/drivers/staging/rtl8723bs/include/osdep_service.h
index b49838c7e457..bde415db4114 100644
--- a/drivers/staging/rtl8723bs/include/osdep_service.h
+++ b/drivers/staging/rtl8723bs/include/osdep_service.h
@@ -14,10 +14,6 @@
 
 #include <osdep_service_linux.h>
 
-#ifndef BIT
-	#define BIT(x)	(1 << (x))
-#endif
-
 #define BIT0	0x00000001
 #define BIT1	0x00000002
 #define BIT2	0x00000004
diff --git a/drivers/staging/rtl8723bs/include/wifi.h b/drivers/staging/rtl8723bs/include/wifi.h
index 0bd7b662b972..f03e26818d45 100644
--- a/drivers/staging/rtl8723bs/include/wifi.h
+++ b/drivers/staging/rtl8723bs/include/wifi.h
@@ -7,14 +7,6 @@
 #ifndef _WIFI_H_
 #define _WIFI_H_
 
-
-#ifdef BIT
-/* error	"BIT define occurred earlier elsewhere!\n" */
-#undef BIT
-#endif
-#define BIT(x)	(1 << (x))
-
-
 #define WLAN_ETHHDR_LEN		14
 #define WLAN_ETHADDR_LEN	6
 #define WLAN_IEEE_OUI_LEN	3
-- 
2.20.1


^ permalink raw reply	[flat|nested] 3+ messages in thread

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