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* [PATCH] staging: rtl8723bs: remove unused BIT macros definitions
@ 2021-07-30 13:21 Fabio Aiuto
  2021-07-30 13:32 ` Greg KH
  0 siblings, 1 reply; 5+ messages in thread
From: Fabio Aiuto @ 2021-07-30 13:21 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>
---
 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] 5+ messages in thread

* Re: [PATCH] staging: rtl8723bs: remove unused BIT macros definitions
  2021-07-30 13:21 [PATCH] staging: rtl8723bs: remove unused BIT macros definitions Fabio Aiuto
@ 2021-07-30 13:32 ` Greg KH
  2021-07-30 13:35   ` Fabio Aiuto
  0 siblings, 1 reply; 5+ messages in thread
From: Greg KH @ 2021-07-30 13:32 UTC (permalink / raw)
  To: Fabio Aiuto
  Cc: hdegoede, Larry.Finger, linux-staging, linux-kernel, David Sterba

On Fri, Jul 30, 2021 at 03:21:03PM +0200, Fabio Aiuto wrote:
> 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
> ---

Don't put "---" in a changelog text, otherwise the signed-off-by will be
cut off.  Can you resend it with that changed to something else like
"---------------" or anything else?

thanks,

greg k-h

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] staging: rtl8723bs: remove unused BIT macros definitions
  2021-07-30 13:32 ` Greg KH
@ 2021-07-30 13:35   ` Fabio Aiuto
  0 siblings, 0 replies; 5+ messages in thread
From: Fabio Aiuto @ 2021-07-30 13:35 UTC (permalink / raw)
  To: Greg KH; +Cc: hdegoede, Larry.Finger, linux-staging, linux-kernel, David Sterba

Hello Greg,

On Fri, Jul 30, 2021 at 03:32:36PM +0200, Greg KH wrote:
> On Fri, Jul 30, 2021 at 03:21:03PM +0200, Fabio Aiuto wrote:
> > 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
> > ---
> 
> Don't put "---" in a changelog text, otherwise the signed-off-by will be
> cut off.  Can you resend it with that changed to something else like
> "---------------" or anything else?
> 
> thanks,
> 
> greg k-h

sure I'm about to send a v2,

thank you,

fabio

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] staging: rtl8723bs: remove unused BIT macros definitions
  2021-07-30 13:19 Fabio Aiuto
@ 2021-07-30 13:23 ` Fabio Aiuto
  0 siblings, 0 replies; 5+ messages in thread
From: Fabio Aiuto @ 2021-07-30 13:23 UTC (permalink / raw)
  To: gregkh, hdegoede, Larry.Finger, linux-staging, linux-kernel,
	David Sterba

Hi all,

sorry, I missed the To: field, ignore this one.

Thank you,

fabio

^ permalink raw reply	[flat|nested] 5+ messages in thread

* [PATCH] staging: rtl8723bs: remove unused BIT macros definitions
@ 2021-07-30 13:19 Fabio Aiuto
  2021-07-30 13:23 ` Fabio Aiuto
  0 siblings, 1 reply; 5+ messages in thread
From: Fabio Aiuto @ 2021-07-30 13:19 UTC (permalink / raw)
  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>
---
 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] 5+ messages in thread

end of thread, other threads:[~2021-07-30 13:35 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2021-07-30 13:21 [PATCH] staging: rtl8723bs: remove unused BIT macros definitions Fabio Aiuto
2021-07-30 13:32 ` Greg KH
2021-07-30 13:35   ` Fabio Aiuto
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2021-07-30 13:19 Fabio Aiuto
2021-07-30 13:23 ` Fabio Aiuto

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