[ARM64,v4.4,V3,40/44] arm/arm64: smccc: Make function identifiers an unsigned quantity

Message ID 9bafd5233bd85eb31c7780a5d1149943da897e23.1567077734.git.viresh.kumar@linaro.org
State New
Headers show
Series
  • V4.4 backport of arm64 Spectre patches
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Commit Message

Viresh Kumar Aug. 29, 2019, 11:34 a.m.
From: Marc Zyngier <marc.zyngier@arm.com>


commit ded4c39e93f3b72968fdb79baba27f3b83dad34c upstream.

Function identifiers are a 32bit, unsigned quantity. But we never
tell so to the compiler, resulting in the following:

 4ac:   b26187e0        mov     x0, #0xffffffff80000001

We thus rely on the firmware narrowing it for us, which is not
always a reasonable expectation.

Cc: stable@vger.kernel.org
Reported-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

Reviewed-by: Robin Murphy <robin.murphy@arm.com>

Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

---
 include/linux/arm-smccc.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

-- 
2.21.0.rc0.269.g1a574e7a288b

Patch

diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h
index 1f02e4045a9e..4c45fd75db5d 100644
--- a/include/linux/arm-smccc.h
+++ b/include/linux/arm-smccc.h
@@ -16,6 +16,7 @@ 
 
 #include <linux/linkage.h>
 #include <linux/types.h>
+#include <uapi/linux/const.h>
 
 /*
  * This file provides common defines for ARM SMC Calling Convention as
@@ -23,8 +24,8 @@ 
  * http://infocenter.arm.com/help/topic/com.arm.doc.den0028a/index.html
  */
 
-#define ARM_SMCCC_STD_CALL		0
-#define ARM_SMCCC_FAST_CALL		1
+#define ARM_SMCCC_STD_CALL	        _AC(0,U)
+#define ARM_SMCCC_FAST_CALL	        _AC(1,U)
 #define ARM_SMCCC_TYPE_SHIFT		31
 
 #define ARM_SMCCC_SMC_32		0