Home » Mailing list archives » linux-kernel » 2010 » April » 13

Re: [PATCH v2] xtables: make XT_ALIGN() usable in exported headers by exporting __ALIGN_KERNEL()

Previous thread: Re: USB transfer_buffer allocations on 64bit systems by Alan Stern on Wednesday, April 7, 2010 - 9:04 am. (1 message)

Next thread: [PATCH tip/urgent] rcu: add rcu_access_pointer and rcu_dereference_protected by Paul E. McKenney on Wednesday, April 7, 2010 - 9:26 am. (10 messages)
[view original message]
From: Alexey Dobriyan
Subject: [PATCH] xtables: make XT_ALIGN() usable in exported headers by exporting __ALIGN_KERNEL()
Date: Wednesday, April 7, 2010 - 9:22 am

XT_ALIGN() was rewritten through ALIGN() by commit 42107f5009da223daa800d6da6904d77297ae829
"netfilter: xtables: symmetric COMPAT_XT_ALIGN definition".
ALIGN() is not exported in userspace headers, which created compile problem for tc(8)
and will create problem for iptables(8).

We can't export generic looking name ALIGN() but we can export less generic
__ALIGN_KERNEL() (suggested by Ben Hutchings).
Google knows nothing about __ALIGN_KERNEL().

COMPAT_XT_ALIGN() changed for symmetry.

Reported-by: Andreas Henriksson <andreas@fatal.se>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
---

 include/linux/kernel.h             |    5 +++--
 include/linux/netfilter/x_tables.h |    6 +++---
 2 files changed, 6 insertions(+), 5 deletions(-)

--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -4,6 +4,8 @@
 /*
  * 'kernel.h' contains some often-used function prototypes etc
  */
+#define __ALIGN_KERNEL(x, a)		__ALIGN_KERNEL_MASK(x, (typeof(x))(a) - 1)
+#define __ALIGN_KERNEL_MASK(x, mask)	(((x) + (mask)) & ~(mask))
 
 #ifdef __KERNEL__
 
@@ -37,8 +39,7 @@ extern const char linux_proc_banner[];
 
 #define STACK_MAGIC	0xdeadbeef
 
-#define ALIGN(x,a)		__ALIGN_MASK(x,(typeof(x))(a)-1)
-#define __ALIGN_MASK(x,mask)	(((x)+(mask))&~(mask))
+#define ALIGN(x, a)		__ALIGN_KERNEL((x), (a))
 #define PTR_ALIGN(p, a)		((typeof(p))ALIGN((unsigned long)(p), (a)))
 #define IS_ALIGNED(x, a)		(((x) & ((typeof(x))(a) - 1)) == 0)
 
--- a/include/linux/netfilter/x_tables.h
+++ b/include/linux/netfilter/x_tables.h
@@ -1,6 +1,6 @@
 #ifndef _X_TABLES_H
 #define _X_TABLES_H
-
+#include <linux/kernel.h>
 #include <linux/types.h>
 
 #define XT_FUNCTION_MAXNAMELEN 30
@@ -93,7 +93,7 @@ struct _xt_align {
 	__u64 u64;
 };
 
-#define XT_ALIGN(s) ALIGN((s), __alignof__(struct _xt_align))
+#define XT_ALIGN(s) __ALIGN_KERNEL((s), __alignof__(struct _xt_align))
 
 /* Standard return verdict, or do jump. */
 #define XT_STANDARD_TARGET ""
@@ -598,7 +598,7 @@ struct _compat_xt_align ...
[ message continues ]
[view original message]
From: Patrick McHardy
Subject: Re: [PATCH] xtables: make XT_ALIGN() usable in exported headers by exporting __ALIGN_KERNEL()
Date: Tuesday, April 13, 2010 - 2:22 am

Since there haven't been any objections, I've applied your patch.
Thanks.
--


[ message continues ]
[view original message]
From: Patrick McHardy
Subject: Re: [PATCH] xtables: make XT_ALIGN() usable in exported headers by exporting __ALIGN_KERNEL()
Date: Tuesday, April 13, 2010 - 3:01 am

This breaks compilation by removing __ALIGN_MASK(). Please fix this up.
--


[ message continues ]
[view original message]
From: Alexey Dobriyan
Subject: [PATCH v2] xtables: make XT_ALIGN() usable in exported headers by exporting __ALIGN_KERNEL()
Date: Wednesday, April 14, 2010 - 5:07 am

XT_ALIGN() was rewritten through ALIGN() by commit 42107f5009da223daa800d6da6904d77297ae829
"netfilter: xtables: symmetric COMPAT_XT_ALIGN definition".
ALIGN() is not exported in userspace headers, which created compile problem for tc(8)
and will create problem for iptables(8).

We can't export generic looking name ALIGN() but we can export less generic
__ALIGN_KERNEL() (suggested by Ben Hutchings).
Google knows nothing about __ALIGN_KERNEL().

COMPAT_XT_ALIGN() changed for symmetry.

Reported-by: Andreas Henriksson <andreas@fatal.se>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
---

 include/linux/kernel.h             |    6 ++++--
 include/linux/netfilter/x_tables.h |    6 +++---
 2 files changed, 7 insertions(+), 5 deletions(-)

--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -4,6 +4,8 @@
 /*
  * 'kernel.h' contains some often-used function prototypes etc
  */
+#define __ALIGN_KERNEL(x, a)		__ALIGN_KERNEL_MASK(x, (typeof(x))(a) - 1)
+#define __ALIGN_KERNEL_MASK(x, mask)	(((x) + (mask)) & ~(mask))
 
 #ifdef __KERNEL__
 
@@ -37,8 +39,8 @@ extern const char linux_proc_banner[];
 
 #define STACK_MAGIC	0xdeadbeef
 
-#define ALIGN(x,a)		__ALIGN_MASK(x,(typeof(x))(a)-1)
-#define __ALIGN_MASK(x,mask)	(((x)+(mask))&~(mask))
+#define ALIGN(x, a)		__ALIGN_KERNEL((x), (a))
+#define __ALIGN_MASK(x, mask)	__ALIGN_KERNEL_MASK((x), (mask))
 #define PTR_ALIGN(p, a)		((typeof(p))ALIGN((unsigned long)(p), (a)))
 #define IS_ALIGNED(x, a)		(((x) & ((typeof(x))(a) - 1)) == 0)
 
diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h
index 84c7c92..f01ddbe 100644
--- a/include/linux/netfilter/x_tables.h
+++ b/include/linux/netfilter/x_tables.h
@@ -1,6 +1,6 @@
 #ifndef _X_TABLES_H
 #define _X_TABLES_H
-
+#include <linux/kernel.h>
 #include <linux/types.h>
 
 #define XT_FUNCTION_MAXNAMELEN 30
@@ -93,7 +93,7 @@ struct _xt_align {
 	__u64 u64;
 };
 
-#define XT_ALIGN(s) ALIGN((s), __alignof__(struct _xt_align))
+#define ...
[ message continues ]
[view original message]
From: Patrick McHardy
Subject: Re: [PATCH v2] xtables: make XT_ALIGN() usable in exported headers by exporting __ALIGN_KERNEL()
Date: Tuesday, April 13, 2010 - 4:08 am

I've already pushed your change out, could you send me an incremental
fix please?

master.kernel.org:/pub/scm/linux/kernel/git/kaber/nf-next-2.6.git
--


[ message continues ]
[view original message]
From: Alexey Dobriyan
Subject: Re: [PATCH v2] xtables: make XT_ALIGN() usable in exported headers by exporting __ALIGN_KERNEL()
Date: Wednesday, April 14, 2010 - 5:50 am

[PATCH] Restore __ALIGN_MASK()

Fix lib/bitmap.c compile failure due to __ALIGN_KERNEL changes.

---
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -40,6 +40,7 @@ extern const char linux_proc_banner[];
 #define STACK_MAGIC	0xdeadbeef
 
 #define ALIGN(x, a)		__ALIGN_KERNEL((x), (a))
+#define __ALIGN_MASK(x, mask)	__ALIGN_KERNEL_MASK((x), (mask))
 #define PTR_ALIGN(p, a)		((typeof(p))ALIGN((unsigned long)(p), (a)))
 #define IS_ALIGNED(x, a)		(((x) & ((typeof(x))(a) - 1)) == 0)
 
--


[ message continues ]
[view original message]
From: Patrick McHardy
Subject: Re: [PATCH v2] xtables: make XT_ALIGN() usable in exported headers by exporting __ALIGN_KERNEL()
Date: Tuesday, April 13, 2010 - 5:10 am

Applied.
--


[ message continues ]
Previous thread: Re: USB transfer_buffer allocations on 64bit systems by Alan Stern on Wednesday, April 7, 2010 - 9:04 am. (1 message)

Next thread: [PATCH tip/urgent] rcu: add rcu_access_pointer and rcu_dereference_protected by Paul E. McKenney on Wednesday, April 7, 2010 - 9:26 am. (10 messages)