1 files changed, 48 insertions, 13 deletions

diff --git a/arch/um/include/sysdep-x86_64/stub.h b/arch/um/include/sysdep-x86_64/stub.h
index f599058d8263..2bd6e7a97286 100644
--- a/arch/um/include/sysdep-x86_64/stub.h
+++ b/arch/um/include/sysdep-x86_64/stub.h
@@ -17,37 +17,72 @@ extern void stub_clone_handler(void);
 #define STUB_MMAP_NR __NR_mmap
 #define MMAP_OFFSET(o) (o)
 
+#define __syscall_clobber "r11","rcx","memory"
+#define __syscall "syscall"
+
 static inline long stub_syscall2(long syscall, long arg1, long arg2)
 {
 	long ret;
 
-	__asm__("movq %0, %%rsi; " : : "g" (arg2) : "%rsi");
-	__asm__("movq %0, %%rdi; " : : "g" (arg1) : "%rdi");
-	__asm__("movq %0, %%rax; " : : "g" (syscall) : "%rax");
-	__asm__("syscall;" : : : "%rax", "%r11", "%rcx");
-	__asm__ __volatile__("movq %%rax, %0; " : "=g" (ret) :);
-	return(ret);
+	__asm__ volatile (__syscall
+		: "=a" (ret)
+		: "0" (syscall), "D" (arg1), "S" (arg2) : __syscall_clobber );
+
+	return ret;
 }
 
 static inline long stub_syscall3(long syscall, long arg1, long arg2, long arg3)
 {
-	__asm__("movq %0, %%rdx; " : : "g" (arg3) : "%rdx");
-	return(stub_syscall2(syscall, arg1, arg2));
+	long ret;
+
+	__asm__ volatile (__syscall
+		: "=a" (ret)
+		: "0" (syscall), "D" (arg1), "S" (arg2), "d" (arg3)
+		: __syscall_clobber );
+
+	return ret;
 }
 
 static inline long stub_syscall4(long syscall, long arg1, long arg2, long arg3,
 				 long arg4)
 {
-	__asm__("movq %0, %%r10; " : : "g" (arg4) : "%r10");
-	return(stub_syscall3(syscall, arg1, arg2, arg3));
+	long ret;
+
+	__asm__ volatile ("movq %5,%%r10 ; " __syscall
+		: "=a" (ret)
+		: "0" (syscall), "D" (arg1), "S" (arg2), "d" (arg3),
+		  "g" (arg4)
+		: __syscall_clobber, "r10" );
+
+	return ret;
+}
+
+static inline long stub_syscall5(long syscall, long arg1, long arg2, long arg3,
+				 long arg4, long arg5)
+{
+	long ret;
+
+	__asm__ volatile ("movq %5,%%r10 ; movq %6,%%r8 ; " __syscall
+		: "=a" (ret)
+		: "0" (syscall), "D" (arg1), "S" (arg2), "d" (arg3),
+		  "g" (arg4), "g" (arg5)
+		: __syscall_clobber, "r10", "r8" );
+
+	return ret;
 }
 
 static inline long stub_syscall6(long syscall, long arg1, long arg2, long arg3,
 				 long arg4, long arg5, long arg6)
 {
-	__asm__("movq %0, %%r9; " : : "g" (arg6) : "%r9");
-	__asm__("movq %0, %%r8; " : : "g" (arg5) : "%r8");
-	return(stub_syscall4(syscall, arg1, arg2, arg3, arg4));
+	long ret;
+
+	__asm__ volatile ("movq %5,%%r10 ; movq %6,%%r8 ; "
+		"movq %7, %%r9; " __syscall : "=a" (ret)
+		: "0" (syscall), "D" (arg1), "S" (arg2), "d" (arg3),
+		  "g" (arg4), "g" (arg5), "g" (arg6)
+		: __syscall_clobber, "r10", "r8", "r9" );
+
+	return ret;
 }
 
 static inline void trap_myself(void)