s390x: modernize assembly code

arch/s390x/defs.h

@@ -1,8 +1,15 @@
 #ifndef __ARCH_S390X_DEFS_H
 #define __ARCH_S390X_DEFS_H
 
-#define OFFSET_GREGS	(56)
+#define REG_SZ		(8)
-#define OFFSET_AREGS	(184)
+#define AREG_SZ		(4)
-#define OFFSET_FPREGS	(248)
+
+#define MCONTEXT_GREGS	(56)
+#define MCONTEXT_AREGS	(184)
+#define MCONTEXT_FPREGS	(248)
+
+#define AREG_OFFSET(__reg)	(MCONTEXT_AREGS + ((__reg) * AREG_SZ))
+
+#include "common-defs.h"
 
 #endif

arch/s390x/getcontext.S

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018 Ariadne Conill <ariadne@dereferenced.org>
+ * Copyright (c) 2018, 2020 Ariadne Conill <ariadne@dereferenced.org>
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -12,17 +12,14 @@
 
 #include "defs.h"
 
+ALIAS(getcontext, __getcontext)
 
-.globl __getcontext;
+FUNC(__getcontext)
-__getcontext:
 	lgr	%r1, %r2			/* use %r1 as our working register */
 	la	%r2, 0				/* we will return 0 */
 
-	stam	%a0, %a15, OFFSET_AREGS(%r1)	/* store access registers */
+	stam	%a0, %a15, AREG_OFFSET(0)(%r1)	/* store access registers */
-	stmg	%r0, %r15, OFFSET_GREGS(%r1)	/* store general-purpose registers */
+	stmg	%r0, %r15, REG_OFFSET(0)(%r1)	/* store general-purpose registers */
 
 	br	%r14				/* return to where we came from */
-
+END(__getcontext)
-
-.weak getcontext;
-getcontext = __getcontext;

arch/s390x/makecontext.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018 Ariadne Conill <ariadne@dereferenced.org>
+ * Copyright (c) 2018, 2020 Ariadne Conill <ariadne@dereferenced.org>
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above

arch/s390x/setcontext.S

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018 Ariadne Conill <ariadne@dereferenced.org>
+ * Copyright (c) 2018, 2020 Ariadne Conill <ariadne@dereferenced.org>
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -12,16 +12,13 @@
 
 #include "defs.h"
 
+ALIAS(setcontext, __setcontext)
 
-.globl __setcontext;
+FUNC(__setcontext)
-__setcontext:
 	lgr	%r1, %r2			/* use %r1 as our working register */
 
-	lam	%a2, %a15, OFFSET_AREGS+8(%r1)	/* load access registers, but skip %a0 and %a1 which are for TLS */
+	lam	%a2, %a15, AREG_OFFSET(2)(%r1)	/* load access registers, but skip %a0 and %a1 which are for TLS */
-	lmg	%r0, %r15, OFFSET_GREGS(%r1)	/* store general-purpose registers */
+	lmg	%r0, %r15, REG_OFFSET(0)(%r1)	/* store general-purpose registers */
 
 	br	%r14				/* return to new link register address */
-
+END(__setcontext)
-
-.weak setcontext;
-setcontext = __setcontext;

arch/s390x/startcontext.S

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018 Ariadne Conill <ariadne@dereferenced.org>
+ * Copyright (c) 2018, 2020 Ariadne Conill <ariadne@dereferenced.org>
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -12,9 +12,7 @@
 
 #include "defs.h"
 
-
+FUNC(__start_context)
-.globl __start_context;
-__start_context:
 	basr	%r14, %r7			/* run function pointer (%r7) and return here */
 	ltgr	%r8, %r8			/* check to see if uc_link (%r8) is null */
 
@@ -28,3 +26,4 @@ no_linked_context:
 	brasl	%r14, exit@plt			/* call exit */
 
 	j	.+2				/* crash if exit returns */
+END(__start_context)

arch/s390x/swapcontext.S

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018 Ariadne Conill <ariadne@dereferenced.org>
+ * Copyright (c) 2018, 2020 Ariadne Conill <ariadne@dereferenced.org>
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -12,21 +12,18 @@
 
 #include "defs.h"
 
+ALIAS(swapcontext, __swapcontext)
 
-.globl __swapcontext;
+FUNC(__swapcontext)
-__swapcontext:
 	lgr	%r1, %r2			/* use %r1 to save current context to */
 	lgr	%r0, %r3			/* use %r0 for source context */
 
-	stam	%a0, %a15, OFFSET_AREGS(%r1)	/* store access registers */
+	stam	%a0, %a15, AREG_OFFSET(0)(%r1)	/* store access registers */
-	stmg	%r0, %r15, OFFSET_GREGS(%r1)	/* store general-purpose registers */
+	stmg	%r0, %r15, REG_OFFSET(0)(%r1)	/* store general-purpose registers */
 
 	lgr	%r2, %r0			/* swap %r0 to %r2 (XXX: figure out why it hates loading from %r0) */
-	lam	%a2, %a15, OFFSET_AREGS+8(%r2)	/* load access registers, but skip %a0 and %a1 which are for TLS */
+	lam	%a2, %a15, AREG_OFFSET(2)(%r2)	/* load access registers, but skip %a0 and %a1 which are for TLS */
-	lmg	%r0, %r15, OFFSET_GREGS(%r2)	/* load general-purpose registers */
+	lmg	%r0, %r15, REG_OFFSET(0)(%r2)	/* load general-purpose registers */
 
 	br	%r14				/* return to new link register address */
-
+END(__swapcontext)
-
-.weak swapcontext;
-swapcontext = __swapcontext;