xtensa: add support for NPTL

Changes from:
https://github.com/foss-xtensa/uClibc/commits/xtensa_nptl

Author: Chris Zankel <chris@zankel.net>
Author: Baruch Siach <baruch@tkos.co.il>

1 files changed, 52 insertions, 52 deletions

diff --git a/libc/sysdeps/linux/xtensa/vfork.S b/libc/sysdeps/linux/xtensa/vfork.S
index f094ae38f..6aced0a50 100644
--- a/libc/sysdeps/linux/xtensa/vfork.S
+++ b/libc/sysdeps/linux/xtensa/vfork.S
@@ -1,4 +1,4 @@
-/* Copyright (C) 2005, 2007 Free Software Foundation, Inc.
+/* Copyright (C) 2005-2013 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -19,72 +19,67 @@
 #include <sys/syscall.h>
 #define _SIGNAL_H
 #include <bits/signum.h>
+#define __ASSEMBLY__
+#include <linux/sched.h>
 
 
-/* Clone the calling process, but without copying the whole address space.
+/*
+   Clone the calling process, but without copying the whole address space.
    The calling process is suspended until the new process exits or is
    replaced by a call to `execve'.  Return -1 for errors, 0 to the new process,
    and the process ID of the new process to the old process.
 
    Note that it is important that we don't create a new stack frame for the
-   caller.  */
+   caller.
 
-
-/* The following are defined in linux/sched.h, which unfortunately
-   is not safe for inclusion in an assembly file.  */
-#define CLONE_VM        0x00000100     /* set if VM shared between processes */
-#define CLONE_VFORK     0x00004000     /* set if the parent wants the child to
-					  wake it up on mm_release */
+*/
 
 #ifndef SAVE_PID
-#define SAVE_PID
+#define SAVE_PID(a,b,c,d)
 #endif
-
 #ifndef RESTORE_PID
-#define RESTORE_PID
+#define RESTORE_PID(a,b,c)
+#endif
+#ifndef RESTORE_PID12
+#define RESTORE_PID12(a,b,c)
 #endif
 
+/*
+   pid_t vfork(void);
+   Implemented as __clone_syscall(CLONE_VFORK | CLONE_VM | SIGCHLD, 0)
+ */
 
-/* pid_t vfork(void);
-   Implemented as __clone_syscall(CLONE_VFORK | CLONE_VM | SIGCHLD, 0) */
 
 HIDDEN_ENTRY (__vfork)
+        .literal .Ljumptable, 0, .L4, .L8, .L12
 
-	movi	a6, .Ljumptable
-	extui	a2, a0, 30, 2		/* call-size: call4/8/12 = 1/2/3 */
-	addx4	a4, a2, a6		/* find return address in jumptable */
-	l32i	a4, a4, 0
-	add	a4, a4, a6
-
+	mov	a3, a0			# move return address out of the way
+	movi	a0, .Ljumptable
+	extui	a2, a3, 30, 2		# call-size: call4/8/12 = 1/2/3
+	addx4	a0, a2, a0		# find return address in jumptable
 	slli	a2, a2, 30
-	xor	a3, a0, a2		/* remove call-size from return addr */
-	extui	a5, a4, 30, 2		/* get high bits of jump target */
-	slli	a5, a5, 30
-	or	a3, a3, a5		/* stuff them into the return address */
-	xor	a4, a4, a5		/* clear high bits of jump target */
-	or	a0, a4, a2		/* create temporary return address */
-	retw				/* "return" to .L4, .L8, or .L12 */
-
-	.align	4
-.Ljumptable:
-	.word	0
-	.word	.L4 - .Ljumptable
-	.word	.L8 - .Ljumptable
-	.word	.L12 - .Ljumptable
+	l32i	a0, a0, 0
+
+	xor	a3, a3, a2		# remove call-size from return address
+	or	a0, a0, a2		# create temporary return address
+	retw
 
 	/* a7: return address */
+
 .L4:	mov	a12, a2
 	mov	a13, a3
 
-	SAVE_PID
+	SAVE_PID(a5,a15,a2,a3)
+
+	/* use syscall 'clone' and set new stack pointer to the same address */
 
-	/* Use syscall 'clone'.  Set new stack pointer to the same address.  */
-	movi	a2, SYS_ify (clone)
+	movi	a2, SYS_ify(clone)
 	movi	a3, 0
 	movi	a6, CLONE_VM | CLONE_VFORK | SIGCHLD
+
         syscall
 
-	RESTORE_PID
+	RESTORE_PID(a5,a15,a2)
 
 	movi	a5, -4096
 
@@ -94,22 +89,24 @@ HIDDEN_ENTRY (__vfork)
 
 	bgeu	a6, a5, 1f
 	jx	a7
-1:	call4	.Lerr			/* returns to original caller */
 
+1:	call4	.Lerr
 
 	/* a11: return address */
+
 .L8:	mov	a12, a2
 	mov	a13, a3
 	mov	a14, a6
 
-	SAVE_PID
+	SAVE_PID(a9,a15,a2,a3)
 
-	movi	a2, SYS_ify (clone)
+	movi	a2, SYS_ify(clone)
 	movi	a3, 0
 	movi	a6, CLONE_VM | CLONE_VFORK | SIGCHLD
+
 	syscall
 
-	RESTORE_PID
+	RESTORE_PID(a9,a15,a2)
 
 	movi	a9, -4096
 
@@ -120,22 +117,25 @@ HIDDEN_ENTRY (__vfork)
 
 	bgeu	a10, a9, 1f
 	jx	a11
-1:	call8	.Lerr			/* returns to original caller */
+
+1:	call8	.Lerr
 
 
 	/* a15: return address */
+
 .L12:	mov	a12, a2
 	mov	a13, a3
 	mov	a14, a6
 
-	SAVE_PID
+	SAVE_PID (a2,a3,a2,a6)
 
-	movi	a2, SYS_ify (clone)
+	movi	a2, SYS_ify(clone)
 	movi	a3, 0
 	movi	a6, CLONE_VM | CLONE_VFORK | SIGCHLD
+
 	syscall
 
-	RESTORE_PID
+	RESTORE_PID12(a3,a6,a15)
 
 	mov	a3, a13
 	movi	a13, -4096
@@ -147,18 +147,18 @@ HIDDEN_ENTRY (__vfork)
 
 	bgeu	a14, a13, 1f
 	jx	a15
-1:	call12	.Lerr			/* returns to original caller */
 
+1:	call12	.Lerr
 
 	.align 4
+
 .Lerr:	entry	a1, 16
 
-	/* Restore the return address.  */
-	extui	a4, a0, 30, 2		/* get the call-size bits */
+	/* Restore return address */
+
+	extui	a4, a0, 30, 2
 	slli	a4, a4, 30
-	slli	a3, a3, 2		/* clear high bits of target address */
-	srli	a3, a3, 2
-	or	a0, a3, a4		/* combine them */
+	or	a0, a3, a4
 
 	PSEUDO_END (__vfork)
 .Lpseudo_end: