From: Lino Sanfilippo <lsanfil@marvell.com>
To: <linux@arm.linux.org.uk>, <linux-arm-kernel@lists.infradead.org>
Cc: <linux-kernel@vger.kernel.org>, <LinoSanfilippo@gmx.de>,
Lino Sanfilippo <lsanfil@marvell.com>
Subject: [RFC PATCH 1/1] ARM: Ensure correct structure alignment when using compiler attribute "section"
Date: Mon, 2 Mar 2015 11:01:42 +0100 [thread overview]
Message-ID: <1425290502-2322-2-git-send-email-lsanfil@marvell.com> (raw)
In-Reply-To: <1425290502-2322-1-git-send-email-lsanfil@marvell.com>
In some cases structures are placed into dedicated sections by means of the
"section" compiler attribute and then accessed as elements of an array (e.g when
the __clk_of_table is set up which contains all potential clock providers - see
CLK_OF_DECLARE).
But even if the size of such a structure is a multiple of the processors word
size, the linker may decide to use an even greater alignment and thus use
padding in between the structures. In this case accessing a structure as an
array element is not possible. To avoid such padding and thus allow to access
such a structure as an array element enforce an alignment of processor word size
by means of the "aligned" attribute.
Signed-off-by: Lino Sanfilippo <lsanfil@marvell.com>
---
include/linux/compiler.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 33063f8..6f32128 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -371,7 +371,8 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
/* Simple shorthand for a section definition */
#ifndef __section
-# define __section(S) __attribute__ ((__section__(#S)))
+# define __section(S) __attribute__ ((__section__(#S))) \
+ __aligned(sizeof(void *))
#endif
#ifndef __visible
--
1.9.1
next prev parent reply other threads:[~2015-03-02 10:02 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-02 10:01 [RFC PATCH 0/1] Wrong structure alignment due to " Lino Sanfilippo
2015-03-02 10:01 ` Lino Sanfilippo [this message]
2015-03-03 14:41 ` Dave Martin
2015-03-04 11:40 ` sanfilippo
2015-03-04 14:35 ` Dave Martin
2015-03-04 16:29 ` Lino Sanfilippo
2015-03-05 12:26 ` Dave Martin
2015-03-05 13:20 ` Lino Sanfilippo
2015-03-05 13:47 ` Dave Martin
2015-03-05 15:32 ` Lino Sanfilippo
2015-03-05 17:33 ` Dave Martin
2015-03-06 14:02 ` Lino Sanfilippo
2015-03-06 18:20 ` Lino Sanfilippo
2015-03-22 0:56 ` Lino Sanfilippo
2015-03-24 12:07 ` Dave Martin
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