restorer: wrapped the assembly code calling sys_clone into the macro RUN_CLONE_RESTORE_FN.

Signed-off-by: Alexander Kartashov <alekskartashov@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

arch/x86/include/asm/restorer.h

@@ -82,6 +82,44 @@ struct rt_sigframe {
 		     : "r"(new_sp)					\
 		     : "rax","rsp","memory")
 
+#define RUN_CLONE_RESTORE_FN(ret, clone_flags, new_sp, parent_tid,      \
+			     thread_args, clone_restore_fn)             \
+	asm volatile(							\
+		     "clone_emul:				\n"	\
+		     "movq %2, %%rsi				\n"	\
+		     "subq $16, %%rsi			        \n"	\
+		     "movq %6, %%rdi				\n"	\
+		     "movq %%rdi, 8(%%rsi)			\n"	\
+		     "movq %5, %%rdi				\n"	\
+		     "movq %%rdi, 0(%%rsi)			\n"	\
+		     "movq %1, %%rdi				\n"	\
+		     "movq %3, %%rdx				\n"	\
+		     "movq %4, %%r10				\n"	\
+		     "movl $"__stringify(__NR_clone)", %%eax	\n"	\
+		     "syscall				        \n"	\
+									\
+		     "testq %%rax,%%rax			        \n"	\
+		     "jz thread_run				\n"	\
+									\
+		     "movq %%rax, %0				\n"	\
+		     "jmp clone_end				\n"	\
+									\
+		     "thread_run:				\n"	\
+		     "xorq %%rbp, %%rbp			        \n"	\
+		     "popq %%rax				\n"	\
+		     "popq %%rdi				\n"	\
+		     "callq *%%rax				\n"	\
+									\
+		     "clone_end:				\n"	\
+		     : "=r"(ret)					\
+		     : "g"(clone_flags),				\
+		       "g"(new_sp),					\
+		       "g"(&parent_tid),				\
+		       "g"(&thread_args[i].pid),			\
+		       "g"(clone_restore_fn),				\
+		       "g"(&thread_args[i])				\
+		     : "rax", "rdi", "rsi", "rdx", "r10", "memory")
+
 
 int restore_gpregs(struct rt_sigframe *f, UserX86RegsEntry *r);
 

pie/restorer.c

@@ -638,41 +638,8 @@ long __export_restore_task(struct task_restore_core_args *args)
 			 * thread will run with own stack and we must not
 			 * have any additional instructions... oh, dear...
 			 */
-			asm volatile(
-				"clone_emul:				\n"
-				"movq %2, %%rsi				\n"
-				"subq $16, %%rsi			\n"
-				"movq %6, %%rdi				\n"
-				"movq %%rdi, 8(%%rsi)			\n"
-				"movq %5, %%rdi				\n"
-				"movq %%rdi, 0(%%rsi)			\n"
-				"movq %1, %%rdi				\n"
-				"movq %3, %%rdx				\n"
-				"movq %4, %%r10				\n"
-				"movl $"__stringify(__NR_clone)", %%eax	\n"
-				"syscall				\n"
-
-				"testq %%rax,%%rax			\n"
-				"jz thread_run				\n"
-
-				"movq %%rax, %0				\n"
-				"jmp clone_end				\n"
-
-				"thread_run:				\n"	/* new stack here */
-				"xorq %%rbp, %%rbp			\n"	/* clear ABI frame pointer */
-				"popq %%rax				\n"	/* clone_restore_fn  -- restore_thread */
-				"popq %%rdi				\n"	/* arguments */
-				"callq *%%rax				\n"
-
-				"clone_end:				\n"
-				: "=r"(ret)
-				:	"g"(clone_flags),
-					"g"(new_sp),
-					"g"(&parent_tid),
-					"g"(&thread_args[i].pid),
-					"g"(args->clone_restore_fn),
-					"g"(&thread_args[i])
-				: "rax", "rdi", "rsi", "rdx", "r10", "memory");
+
+			RUN_CLONE_RESTORE_FN(ret, clone_flags, new_sp, parent_tid, thread_args, args->clone_restore_fn);
 		}
 
 		ret = sys_flock(fd, LOCK_UN);