[PATCH 2/2] [X86] Fix a compilation issue with clang.

From: dl9pf@gmx.de
To: dl9pf@gmx.de
Cc: pageexec@freemail.hu, llvmlinux@lists.linuxfoundation.org,
	behanw@converseincode.com, hpa@zytor.com,
	linux-kernel@vger.kernel.org
Subject: [PATCH 2/2] [X86] Fix a compilation issue with clang.
Date: Thu, 29 Aug 2013 21:13:05 +0200	[thread overview]
Message-ID: <1377803585-5913-3-git-send-email-dl9pf@gmx.de> (raw)
In-Reply-To: <1377803585-5913-1-git-send-email-dl9pf@gmx.de>

From: Jan-Simon Möller <dl9pf@gmx.de>

Clang does not support the "shortcut" we're taking here for gcc (see below).
The patch uses the macro _ASM_DX to do the job.

>From arch/x86/include/asm/uaccess.h:
/*
 * Careful: we have to cast the result to the type of the pointer
 * for sign reasons.
 *
 * The use of %edx as the register specifier is a bit of a
 * simplification, as gcc only cares about it as the starting point
 * and not size: for a 64-bit value it will use %ecx:%edx on 32 bits
 * (%ecx being the next register in gcc's x86 register sequence), and
 * %rdx on 64 bits.
 */

Signed-off-by: Jan-Simon Möller <dl9pf@gmx.de>
CC: pageexec@freemail.hu
CC: llvmlinux@lists.linuxfoundation.org
CC: behanw@converseincode.com
CC: hpa@zytor.com
CC: linux-kernel@vger.kernel.org
---
 arch/x86/include/asm/uaccess.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index 8fa3bd6..32432d1 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -163,7 +163,7 @@ __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))
 #define get_user(x, ptr)						\
 ({									\
 	int __ret_gu;							\
-	register __inttype(*(ptr)) __val_gu asm("%edx");		\
+	register __inttype(*(ptr)) __val_gu asm("%"_ASM_DX);		\
 	__chk_user_ptr(ptr);						\
 	might_fault();							\
 	asm volatile("call __get_user_%P3"				\
-- 
1.8.1.4

