Remove errno declaration in drivers/sbus/char/envctrl.c

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).

@@ -37,7 +37,6 @@
 #include <asm/uaccess.h>
 #include <asm/envctrl.h>
 
-static int errno;
 #include <asm/unistd.h>
 
 #define ENVCTRL_MINOR	162

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

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.

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.

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

Ok, trying this out...

Mathieu Chouquet-Stringer

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...

@@ -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

@@ -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: [email protected]

From: Mathieu Chouquet-Stringer <[email protected]>
Date: Sat, 06 Aug 2005 00:39:11 -0400

Looks good, patch applied, thanks a lot.