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      1 /*
      2  * CDDL HEADER START
      3  *
      4  * The contents of this file are subject to the terms of the
      5  * Common Development and Distribution License (the "License").
      6  * You may not use this file except in compliance with the License.
      7  *
      8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
      9  * or http://www.opensolaris.org/os/licensing.
     10  * See the License for the specific language governing permissions
     11  * and limitations under the License.
     12  *
     13  * When distributing Covered Code, include this CDDL HEADER in each
     14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
     15  * If applicable, add the following below this CDDL HEADER, with the
     16  * fields enclosed by brackets "[]" replaced with your own identifying
     17  * information: Portions Copyright [yyyy] [name of copyright owner]
     18  *
     19  * CDDL HEADER END
     20  */
     21 
     22 /*
     23  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
     24  * Use is subject to license terms.
     25  */
     26 
     27 	.file	"setjmp.s"
     28 
     29 /*
     30  *	longjmp(env, val)
     31  * will generate a "return(val)" from
     32  * the last call to
     33  *	setjmp(env)
     34  * by restoring registers rip rsp rbp rbx r12 r13 r14 r15 from 'env'
     35  * and doing a return.
     36  */
     37 
     38 /*
     39  * entry    reg   offset
     40  * env[0] = %rbx  0	register variables
     41  * env[1] = %r12  8
     42  * env[2] = %r13  16
     43  * env[3] = %r14  24
     44  * env[4] = %r15  32
     45  * env[5] = %rbp  40	stack frame
     46  * env[6] = %rsp  48
     47  * env[7] = %rip  56
     48  */
     49 
     50 #include <sys/asm_linkage.h>
     51 #include <../assym.h>
     52 
     53 	ANSI_PRAGMA_WEAK(setjmp,function)
     54 	ANSI_PRAGMA_WEAK(longjmp,function)
     55 
     56 	ENTRY(setjmp)
     57 	movq	%rbx, 0(%rdi)
     58 	movq	%r12, 8(%rdi)
     59 	movq	%r13, 16(%rdi)
     60 	movq	%r14, 24(%rdi)
     61 	movq	%r15, 32(%rdi)
     62 	movq	%rbp, 40(%rdi)
     63 	popq	%rdx		/* return address */
     64 	movq	%rsp, 48(%rdi)
     65 	movq	%rdx, 56(%rdi)
     66 
     67 	movq	%fs:UL_SIGLINK, %rax
     68 	xorq	%rcx, %rcx
     69 	testq	%rax, %rax	/* are we in a signal handler? */
     70 	jnz	1f
     71 	incq	%rcx		/* no, tell longjmp to clear ul_siglink */
     72 1:	orq	%rcx, 48(%rdi)	/* low-order 1-bit flag in the saved %rsp */
     73 
     74 	xorl	%eax, %eax	/* return 0 */
     75 	jmp	*%rdx
     76 	SET_SIZE(setjmp)
     77 
     78 	ENTRY(longjmp)
     79 	movq	0(%rdi), %rbx
     80 	movq	8(%rdi), %r12
     81 	movq	16(%rdi), %r13
     82 	movq	24(%rdi), %r14
     83 	movq	32(%rdi), %r15
     84 	movq	40(%rdi), %rbp
     85 
     86 	movq	48(%rdi), %rax	/* test low-order bit in the saved %rsp */
     87 	testq	$1, %rax
     88 	jz	1f
     89 	xorq	%rcx, %rcx	/* if set, clear ul_siglink */
     90 	movq	%rcx, %fs:UL_SIGLINK
     91 	subq	$1, %rax	/* clear the flag bit */
     92 1:	movq	%rax, %rsp
     93 
     94 	movl	%esi, %eax
     95 	test	%eax, %eax	/* if val != 0		*/
     96 	jnz	1f		/* 	return val	*/
     97 	incl	%eax		/* else return 1	*/
     98 1:
     99 	movq	56(%rdi), %rdx	/* return to caller of setjmp */
    100 	jmp	*%rdx
    101 	SET_SIZE(longjmp)
    102