m68k: add NPTL/TLS support

Port over NPTL/TLS support from GNU C Library.
In the first step only the slower syscall is used for TLS
access. The uClibc-ng testsuite shows 79 errors, so their
is room for bugfixes and improvements.

1 files changed, 78 insertions, 30 deletions

diff --git a/libc/sysdeps/linux/m68k/clone.S b/libc/sysdeps/linux/m68k/clone.S
index 7eddff10c..24071235b 100644
--- a/libc/sysdeps/linux/m68k/clone.S
+++ b/libc/sysdeps/linux/m68k/clone.S
@@ -1,54 +1,94 @@
-/* Adapted from glibc */
-/* Copyright (C) 1996, 1997 Free Software Foundation, Inc. */
+/* Copyright (C) 1996-2017 Free Software Foundation, Inc.
+   Contributed by Andreas Schwab (schwab@issan.informatik.uni-dortmund.de)
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <http://www.gnu.org/licenses/>.  */
 
 /* clone is even more special than fork as it mucks with stacks
    and invokes a function in the right context after its all over.  */
 
 #define _ERRNO_H
+#include <sysdep.h>
 #include <features.h>
 #include <bits/errno.h>
 #include <sys/syscall.h>
 #include "m68k_pic.S"
 
-/* int _clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg); */
+/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
+	     void *parent_tidptr, void *tls, void *child_tidptr) */
 
-.text
-.align 4
-.type	clone,@function
-.globl	clone;
-clone:
+	.text
+	.align 4
+	.globl	__clone
+	.type	__clone,@function
+
+__clone:
 	/* Sanity check arguments.  */
-	movel   #-EINVAL, %d0
-	movel   4(%sp), %d1             /* no NULL function pointers */
-	movel	%d1, %a0
-	tstl    %d1
+	movel	#-EINVAL, %d0
+	movel	4(%sp), %a0		/* no NULL function pointers */
+	tstl	%a0
 	beq.w	__syscall_error_trampoline
-	movel   8(%sp), %d1             /* no NULL stack pointers */
-	movel	%d1, %a1
-	tstl    %d1
+	movel	8(%sp), %a1		/* no NULL stack pointers */
+	tstl	%a1
 	beq.w   __syscall_error_trampoline
 
 	/* Allocate space and copy the argument onto the new stack.  */
 	movel   16(%sp), -(%a1)
 
 	/* Do the system call */
-#if 1 /* defined (CONFIG_COLDFIRE) */
-	movel   %d2, %d1                /* save %d2 and get stack pointer */
-	movel   %a1, %d2
-	movel   %d1, %a1
+	movel   12(%sp), %d1            /* get flags */
+	movel	%d3, -(%a1)             /* save %d3 and get parent_tidptr */
+	movel	%d3, -(%sp)
+	cfi_adjust_cfa_offset (4)
+	cfi_rel_offset (%d3, 0)
+	movel	20+4(%sp), %d3
+	movel	%d4, -(%a1)		/* save %d4 and get child_tidptr */
+	movel	%d4, -(%sp)
+	cfi_adjust_cfa_offset (4)
+	cfi_rel_offset (%d4, 0)
+	movel	28+8(%sp), %d4
+	movel	%d5, -(%a1)             /* save %d5 and get tls */
+	movel	%d5, -(%sp)
+	cfi_adjust_cfa_offset (4)
+	cfi_rel_offset (%d5, 0)
+	movel	24+12(%sp), %d5
+	/* save %d2 and get stack pointer */
+#ifdef __mcoldfire__
+	movel	%d2, -(%a1)
+	movel	%d2, -(%sp)
+	cfi_adjust_cfa_offset (4)
+	cfi_rel_offset (%d2, 0)
+	movel	%a1, %d2
 #else
-	exg     %d2, %a1                /* save %d2 and get stack pointer */
+	exg	%d2, %a1		/* save %d2 and get stack pointer */
+	cfi_register (%d2, %a1)
 #endif
-	movel   12(%sp), %d1            /* get flags */
 	movel   #__NR_clone, %d0
+
+	/* End FDE now, because in the child the unwind info will be
+	   wrong.  */
+	cfi_endproc
+
 	trap    #0
-#if 1 /* defined (CONFIG_COLDFIRE) */
-	movel   %d2, %d1                /* restore %d2 */
-	movel   %a1, %d2
-	movel   %d1, %a1
+#ifdef __mcoldfire__
+	movel	(%sp)+, %d2
 #else
-	exg     %d2, %a1                /* restore %d2 */
+	exg	%d2, %a1		/* restore %d2 */
 #endif
+	movel	(%sp)+, %d5             /* restore %d5, %d4 and %d3 */
+	movel	(%sp)+, %d4
+	movel	(%sp)+, %d3
 
 	tstl    %d0
 	bmi.w   __syscall_error_trampoline
@@ -57,13 +97,21 @@ clone:
 	rts
 
 thread_start:
-	/*subl    %fp, %fp*/        /* terminate the stack frame */
-	jsr     (%a0)
-	movel   %d0, -(%sp)
+	cfi_startproc
+	cfi_undefined (pc)	/* Mark end of stack */
+	subl	%fp, %fp	/* terminate the stack frame */
+	jsr	(%a0)
+	movel	%d0, %d1
 	movel	#__NR_exit, %d0
 	trap	#0
-	/*jsr    exit*/
+	cfi_endproc
+
+	cfi_startproc
 
 __syscall_error_trampoline:
 	JUMP	__syscall_error,%a0
 
+.size __clone,.-__clone
+
+weak_alias(__clone,clone)
+libc_hidden_def(clone)