[PATCH v2 1/1] ARM : missing corrupted reg in __do_div_asm

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



__xl (R0 in little endian system, or R1 in big endian system) is corrupted
after calling __do_div64 and compiler is not informed about this in
macro __do_div_asm. If n is used again afterwards, __xl won't be
reloaded and n will contain incorrect value.

Signed-off-by: Chen Gang <gangchen@xxxxxxxxxxxx>
---
 arch/arm/include/asm/div64.h | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/arch/arm/include/asm/div64.h b/arch/arm/include/asm/div64.h
index 662c7bd..fa9489e 100644
--- a/arch/arm/include/asm/div64.h
+++ b/arch/arm/include/asm/div64.h
@@ -34,12 +34,14 @@
 	register unsigned long long __n   asm("r0") = n;	\
 	register unsigned long long __res asm("r2");		\
 	register unsigned int __rem       asm(__xh);		\
+	register unsigned int __clobber   asm(__xl);		\
 	asm(	__asmeq("%0", __xh)				\
-		__asmeq("%1", "r2")				\
-		__asmeq("%2", "r0")				\
-		__asmeq("%3", "r4")				\
+		__asmeq("%1", __xl)				\
+		__asmeq("%2", "r2")				\
+		__asmeq("%3", "r0")				\
+		__asmeq("%4", "r4")				\
 		"bl	__do_div64"				\
-		: "=r" (__rem), "=r" (__res)			\
+		: "=r" (__rem), "=r" (__clobber), "=r" (__res)  \
 		: "r" (__n), "r" (__base)			\
 		: "ip", "lr", "cc");				\
 	n = __res;						\
-- 
2.4.2



_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel



[Index of Archives]     [Linux Kernel]     [Linux ARM (vger)]     [Linux ARM MSM]     [Linux Omap]     [CentOS ARM]     [Linux Arm]     [Linux Tegra]     [Fedora ARM]     [Linux for Samsung SOC]     [eCos]     [Linux Fastboot]     [Gcc Help]     [Git]     [DCCP]     [IETF Announce]     [Security]     [Linux MIPS]     [Yosemite Campsites]     [Photos]