From patchwork series 418984

https://patchwork.ozlabs.org//project/linuxppc-dev/list/?series=418984

Author: Fox Snowpatch

tools/testing/selftests/powerpc/benchmarks/Makefile

@@ -18,4 +18,4 @@ $(OUTPUT)/context_switch: LDLIBS += -lpthread
 
 $(OUTPUT)/fork: LDLIBS += -lpthread
 
-$(OUTPUT)/exec_target: CFLAGS += -static -nostartfiles
+$(OUTPUT)/exec_target: CFLAGS += -nostartfiles

tools/testing/selftests/powerpc/benchmarks/exec_target.c

@@ -7,10 +7,22 @@
  */
 
 #define _GNU_SOURCE
-#include <unistd.h>
 #include <sys/syscall.h>
 
 void _start(void)
 {
-	syscall(SYS_exit, 0);
+	asm volatile (
+		"li %%r0, %[sys_exit];"
+		"li %%r3, 0;"
+		"sc;"
+		:
+		: [sys_exit] "i" (SYS_exit)
+		/*
+		 * "sc" will clobber r0, r3-r13, cr0, ctr, xer and memory.
+		 * Even though sys_exit never returns, handle clobber
+		 * registers.
+		 */
+		: "r0", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10",
+		  "r11", "r12", "r13", "cr0", "ctr", "xer", "memory"
+	);
 }