SMC/HVC calls may modify registers x0 to x3. To make sure the compiler
doesn't assume input registers to be constant, also mark these registers
as output when used as input.
Signed-off-by: Oliver Schwartz <oliver.schwa...@gmx.de>
---
hypervisor/arch/arm64/include/asm/smc.h | 13 ++++++-------
include/arch/arm64/asm/jailhouse_hypercall.h | 20 +++++++++++---------
2 files changed, 17 insertions(+), 16 deletions(-)
diff --git a/hypervisor/arch/arm64/include/asm/smc.h
b/hypervisor/arch/arm64/include/asm/smc.h
index 1a5d5c8..c80fe15 100644
--- a/hypervisor/arch/arm64/include/asm/smc.h
+++ b/hypervisor/arch/arm64/include/asm/smc.h
@@ -28,8 +28,8 @@ static inline long smc_arg1(unsigned long id, unsigned long
par1)
register unsigned long __par1 asm("r1") = par1;
asm volatile ("smc #0\n\t"
- : "=r" (__id)
- : "r"(__id), "r"(__par1)
+ : "+r" (__id), "+r"(__par1)
+ :
: "memory", "x2", "x3");
return __id;
@@ -43,8 +43,8 @@ static inline long smc_arg2(unsigned long id, unsigned long
par1,
register unsigned long __par2 asm("r2") = par2;
asm volatile ("smc #0\n\t"
- : "=r" (__id)
- : "r"(__id), "r"(__par1), "r"(__par2)
+ : "+r" (__id), "+r"(__par1), "+r"(__par2)
+ :
: "memory", "x3");
return __id;
@@ -62,9 +62,8 @@ static inline long smc_arg5(unsigned long id, unsigned long
par1,
register unsigned long __par5 asm("r5") = par5;
asm volatile ("smc #0\n\t"
- : "=r" (__id)
- : "r"(__id), "r"(__par1), "r"(__par2), "r"(__par3),
- "r"(__par4), "r"(__par5)
+ : "+r" (__id), "+r"(__par1), "+r"(__par2), "+r"(__par3)
+ : "r"(__par4), "r"(__par5)
: "memory");
return __id;
diff --git a/include/arch/arm64/asm/jailhouse_hypercall.h
b/include/arch/arm64/asm/jailhouse_hypercall.h
index 108d052..a9d13ee 100644
--- a/include/arch/arm64/asm/jailhouse_hypercall.h
+++ b/include/arch/arm64/asm/jailhouse_hypercall.h
@@ -42,6 +42,7 @@
#define JAILHOUSE_CALL_NUM_RESULT "x0"
#define JAILHOUSE_CALL_ARG1 "x1"
#define JAILHOUSE_CALL_ARG2 "x2"
+#define JAILHOUSE_CALL_CLOBBERED "x3"
/* CPU statistics, arm64-specific part */
#define JAILHOUSE_NUM_CPU_STATS
JAILHOUSE_GENERIC_CPU_STATS + 5
@@ -54,9 +55,10 @@ static inline __u64 jailhouse_call(__u64 num)
asm volatile(
JAILHOUSE_CALL_INS
- : "=r" (num_result)
- : "r" (num_result)
- : "memory");
+ : "+r" (num_result)
+ :
+ : "memory", JAILHOUSE_CALL_ARG1, JAILHOUSE_CALL_ARG2,
+ JAILHOUSE_CALL_CLOBBERED);
return num_result;
}
@@ -67,9 +69,9 @@ static inline __u64 jailhouse_call_arg1(__u64 num, __u64 arg1)
asm volatile(
JAILHOUSE_CALL_INS
- : "=r" (num_result)
- : "r" (num_result), "r" (__arg1)
- : "memory");
+ : "+r" (num_result), "+r" (__arg1)
+ :
+ : "memory", JAILHOUSE_CALL_ARG2, JAILHOUSE_CALL_CLOBBERED);
return num_result;
}
@@ -81,9 +83,9 @@ static inline __u64 jailhouse_call_arg2(__u64 num, __u64
arg1, __u64 arg2)
asm volatile(
JAILHOUSE_CALL_INS
- : "=r" (num_result)
- : "r" (num_result), "r" (__arg1), "r" (__arg2)
- : "memory");
+ : "+r" (num_result), "+r" (__arg1), "+r" (__arg2)
+ :
+ : "memory", JAILHOUSE_CALL_CLOBBERED);
return num_result;
}
--
2.7.4
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