[PATCH] Remove errno declaration in drivers/sbus/char/envctrl.c

[PATCH] Remove errno declaration in drivers/sbus/char/envctrl.c

[Mathieu Chouquet-Stringer]

errno is already declarded in linux/errno.h:

drivers/sbus/char/envctrl.c:40: error: static declaration of 'errno' follows non-static declaration
include/linux/unistd.h:4: error: previous declaration of 'errno' was here
make[3]: *** [drivers/sbus/char/envctrl.o] Error 1
make[2]: *** [drivers/sbus/char] Error 2
make[1]: *** [drivers/sbus] Error 2
make: *** [drivers] Error 2


Moreover errno isn't used in this file at all so the following patch
(against latest git tree) just removes it (kernel compiles fine).

Signed-off-by: Mathieu Chouquet-Stringer <mchouque@free.fr>

--- linux-2.6/drivers/sbus/char/envctrl.c	2005-07-25 20:28:43.000000000 -0400
+++ linux-2.6-mat/drivers/sbus/char/envctrl.c	2005-08-04 09:13:48.000000000 -0400
@@ -37,7 +37,6 @@
 #include <asm/uaccess.h>
 #include <asm/envctrl.h>
 
-static int errno;
 #include <asm/unistd.h>
 
 #define ENVCTRL_MINOR	162

Re: [PATCH] Remove errno declaration in drivers/sbus/char/envctrl.c

[David S. Miller]

From: Mathieu Chouquet-Stringer <mchouque@free.fr>
Subject: [PATCH] Remove errno declaration in drivers/sbus/char/envctrl.c
Date: Thu, 04 Aug 2005 09:48:03 -0400

> errno is already declarded in linux/errno.h:

Where?  It _is_ defined in linux/unistd.h and the fact that
we're indirectly getting that header file somehow is the
source of the problem.

> Moreover errno isn't used in this file at all so the following patch
> (against latest git tree) just removes it (kernel compiles fine).

It is used implicitly by the system call macros inside
of asm-*/unistd.h, for example in the _syscall?() macros.

And we do call execve() in envctrl.c which expands to one
of those macros (specifically, _syscall3()).

So you patch is not correct.

Probably the best version of the fix would be to include
linux/unistd.h instead of asm/unistd.h, so you might want
to code that up and test it out.

Re: [PATCH] Remove errno declaration in drivers/sbus/char/envctrl.c

[Mathieu Chouquet-Stringer]

On Thu, Aug 04, 2005 at 07:12:26AM -0700, David S. Miller wrote:
> Where?  It _is_ defined in linux/unistd.h and the fact that
> we're indirectly getting that header file somehow is the
> source of the problem.

Yeah, I guess I shouldn't send emails early in the morning... :-)

> [snip]
> So you patch is not correct.
> 
> Probably the best version of the fix would be to include
> linux/unistd.h instead of asm/unistd.h, so you might want
> to code that up and test it out.

Ok, trying this out...

-- 
Mathieu Chouquet-Stringer

Re: [PATCH] Remove errno declaration in drivers/sbus/char/envctrl.c

[Mathieu Chouquet-Stringer]

On Thu, Aug 04, 2005 at 07:12:26AM -0700, David S. Miller wrote:
> [snip]
> Probably the best version of the fix would be to include
> linux/unistd.h instead of asm/unistd.h, so you might want
> to code that up and test it out.

Thanks for the feedback, what about the following then? It's compiled and
booted and I've realized than bbc_envctrl.c suffers from the same
thing, so here you go. Let me know if it makes sense...

Signed-off-by: Mathieu Chouquet-Stringer <mchouque@free.fr>

--- linux-2.6/drivers/sbus/char/envctrl.c	2005-07-25 20:28:43.000000000 -0400
+++ linux-2.6-mat/drivers/sbus/char/envctrl.c	2005-08-06 00:02:04.000000000 -0400
@@ -32,14 +32,12 @@
 #include <linux/mm.h>
 #include <linux/slab.h>
 #include <linux/kernel.h>
+#include <linux/unistd.h>
 
 #include <asm/ebus.h>
 #include <asm/uaccess.h>
 #include <asm/envctrl.h>
 
-static int errno;
-#include <asm/unistd.h>
-
 #define ENVCTRL_MINOR	162
 
 #define PCF8584_ADDRESS	0x55
--- linux-2.6/drivers/sbus/char/bbc_envctrl.c	2005-07-25 20:28:43.000000000 -0400
+++ linux-2.6-mat/drivers/sbus/char/bbc_envctrl.c	2005-08-06 00:06:27.000000000 -0400
@@ -10,10 +10,9 @@
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/delay.h>
+#include <linux/unistd.h>
 #include <asm/oplib.h>
 #include <asm/ebus.h>
-static int errno;
-#include <asm/unistd.h>
 
 #include "bbc_i2c.h"
 #include "max1617.h"

-- 
Mathieu Chouquet-Stringer                   E-Mail: mchouque@free.fr

Re: [PATCH] Remove errno declaration in drivers/sbus/char/envctrl.c

[David S. Miller]

From: Mathieu Chouquet-Stringer <mchouque@free.fr>
Date: Sat, 06 Aug 2005 00:39:11 -0400

> Thanks for the feedback, what about the following then? It's compiled and
> booted and I've realized than bbc_envctrl.c suffers from the same
> thing, so here you go. Let me know if it makes sense...
> 
> Signed-off-by: Mathieu Chouquet-Stringer <mchouque@free.fr>

Looks good, patch applied, thanks a lot.