sparc: Fix incorrect sigreturn stub function implementation.

This function haven't have prologue/epilogue/cfi directives etc.

Signed-off-by: Dmitry Chestnykh <dm.chestnykh@gmail.com>

libc/sysdeps/linux/sparc/Makefile.arch

@@ -6,7 +6,7 @@
 #
 
 CSRC-y := brk.c __syscall_error.c sigaction.c
-SSRC-y := __longjmp.S setjmp.S bsd-setjmp.S bsd-_setjmp.S \
+SSRC-y := __longjmp.S setjmp.S sigreturn_stub.S bsd-setjmp.S bsd-_setjmp.S \
 	syscall.S urem.S udiv.S umul.S sdiv.S rem.S pipe.S fork.S vfork.S clone.S
 
 CSRC-$(UCLIBC_HAS_CONTEXT_FUNCS) += makecontext.c

libc/sysdeps/linux/sparc/sigaction.c

@@ -30,8 +30,8 @@
 
 
 _syscall5(int, rt_sigaction, int, a, int, b, int, c, int, d, int, e)
-static void __rt_sigreturn_stub(void);
-static void __sigreturn_stub(void);
+void __rt_sigreturn_stub(void);
+void __sigreturn_stub(void);
 
 int __libc_sigaction(int sig, const struct sigaction *act, struct sigaction *oact)
 {
@@ -75,24 +75,3 @@ libc_hidden_weak(sigaction)
 # endif
 #endif
 
-
-static void
-__rt_sigreturn_stub(void)
-{
-	__asm__(
-		"mov %0, %%g1\n\t"
-		"ta  0x10\n\t"
-		: /* no outputs */
-		: "i" (__NR_rt_sigreturn)
-	);
-}
-static void
-__sigreturn_stub(void)
-{
-	__asm__(
-		"mov %0, %%g1\n\t"
-		"ta  0x10\n\t"
-		: /* no outputs */
-		: "i" (__NR_sigreturn)
-	);
-}

libc/sysdeps/linux/sparc/sigreturn_stub.S

@@ -0,0 +1,14 @@
+#include <sysdep.h>
+
+	nop
+	nop
+
+ENTRY_NOCFI (__rt_sigreturn_stub)
+	mov	__NR_rt_sigreturn, %g1
+	ta	0x10
+END_NOCFI (__rt_sigreturn_stub)
+
+ENTRY_NOCFI (__sigreturn_stub)
+	mov	__NR_sigreturn, %g1
+	ta	0x10
+END_NOCFI (__sigreturn_stub)

libc/sysdeps/linux/sparc/sysdep.h

@@ -17,6 +17,15 @@
 C_LABEL(name)                       \
     cfi_startproc;
 
+#define ENTRY_NOCFI(name)			\
+	.align	4;			\
+	.global	C_SYMBOL_NAME(name);	\
+	.type	name, @function;	    \
+C_LABEL(name)
+
+#define END_NOCFI(name)			    \
+	.size name, . - name
+
 #define END(name)                   \
     cfi_endproc;                    \
     .size name, . - name