pie: x86-32 -- Prepare parasite head

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

arch/x86/include/asm/parasite.h

 #ifndef __ASM_PARASITE_H__
 #define __ASM_PARASITE_H__
 
+#ifdef CONFIG_X86_32
+# define __parasite_entry __attribute__((regparm(3)))
+#endif
+
 static inline void arch_get_tls(tls_t *ptls) { (void)ptls; }
 
 #endif

arch/x86/parasite-head.S

@@ -2,6 +2,9 @@
 #include "parasite.h"
 
 	.section .head.text, "ax"
+
+#ifdef CONFIG_X86_64
+
 ENTRY(__export_parasite_head_start)
 	subq	$16, %rsp
 	andq	$~15, %rsp
@@ -15,3 +18,23 @@ ENTRY(__export_parasite_head_start)
 __export_parasite_cmd:
 	.long 0
 END(__export_parasite_head_start)
+
+#else /* CONFIG_X86_64 */
+
+ENTRY(__export_parasite_head_start)
+	subl	$8, %esp
+	andl	$~7, %esp
+	pushl	$0
+	movl	%esp, %ebp
+	call	1f
+1:	popl	%ecx
+2:	leal	(__export_parasite_cmd-2b)(%ecx), %eax
+	leal	(__export_parasite_args-2b)(%ecx), %edx
+	call	parasite_service
+	int	$0x03
+	.align 8
+GLOBAL(__export_parasite_cmd)
+	.long 0
+END(__export_parasite_head_start)
+
+#endif /* CONFIG_X86_64 */

pie/parasite.c

@@ -690,7 +690,11 @@ err:
 	return -1;
 }
 
-int __used parasite_service(unsigned int cmd, void *args)
+#ifndef __parasite_entry
+# define __parasite_entry
+#endif
+
+int __used __parasite_entry parasite_service(unsigned int cmd, void *args)
 {
 	pr_info("Parasite cmd %d/%x process\n", cmd, cmd);