summaryrefslogtreecommitdiff
path: root/libexec/ld.so/amd64/ldasm.S
blob: 07fdf37fa9162e6b9b5c042f3912f2e12e2d3c51 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
/*	$OpenBSD: ldasm.S,v 1.6 2006/05/03 16:10:52 drahn Exp $	*/

/*
 * Copyright (c) 2002,2004 Dale Rahn
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 */


#define DL_DATA_SIZE	(16*8)	 /* 16 * sizeof(ELF_Addr) */
#define DL_LOFF_OFFSET	(7*8)	/* index 7 */
#include <sys/syscall.h>
#include <machine/asm.h>

	.text
	.align	4
	.globl	_dl_start
	.type	_dl_start,@function
_dl_start:
	movq	%rsp, %r12		# save stack pointer for _rtld
	pushq	%rbx			# save ps_strings
	subq	$DL_DATA_SIZE, %rsp	# allocate dl_data

	leaq	_DYNAMIC(%rip),%rdx	# &_DYNAMIC
	movq	%rsp, %rsi		# dl_data for dl_boot_bind
	movq	%r12, %rdi		# load saved SP for dl_boot_bind
	call	_dl_boot_bind@PLT	# _dl_boot_bind(sp,dl_data,dynamicp)

	movq	%rsp, %rcx		# dl_data
	movq	DL_LOFF_OFFSET(%rsp), %rdx		# loff from dl_data

	movq	(%r12), %rdi
	leaq	16(%r12,%rdi,8), %rsi	# envp
	movq	%r12, %rdi
	addq	$8,%rdi			# argv
	call	_dl_boot@PLT		# _dl_boot(argv,envp,loff,dl_data)

	addq	$DL_DATA_SIZE,%rsp	# return dl_data

#	popq	%rbx			# %rbx = ps_strings - XXXDSR
#	popq	%rdx			# %rdx = cleanup - XXXDSR
#	popq	%rcx			# %rcx = obj_main - XXXDSR
	movq	%r12, %rsp
	jmp	*%rax

	.section	".text"

#define	DL_SYSCALL(n) DL_SYSCALL2(n,n)
#define	DL_SYSCALL2(n,c) \
	.global	__CONCAT(_dl_,n)		;\
	.type	__CONCAT(_dl_,n), @function	;\
	.align	4				;\
__CONCAT(_dl_,n):				;\
	movl	$(__CONCAT(SYS_,c)), %eax	;\
	movq	%rcx, %r10			;\
	syscall					;\
	jb	1f				;\
	ret

DL_SYSCALL(open)
DL_SYSCALL(fcntl)
DL_SYSCALL(fstat)
DL_SYSCALL(stat)
DL_SYSCALL(read)
DL_SYSCALL(write)
DL_SYSCALL(close)
DL_SYSCALL(issetugid)
DL_SYSCALL(getdirentries)
DL_SYSCALL(mprotect)
DL_SYSCALL(munmap)
DL_SYSCALL(gettimeofday)
DL_SYSCALL(exit)
DL_SYSCALL2(_syscall,__syscall)
DL_SYSCALL2(sysctl,__sysctl)

1:
	/* error: result = -errno; - handled here. */
	neg	%rax
	ret


	/* _dl_sigprocmask: does not handle NULL new set */

	.align 4
	.global _dl_sigprocmask
	.type _dl_sigprocmask,@function
_dl_sigprocmask:
	movq	(%rsi),%rsi		# fetch indirect...
	movl	$SYS_sigprocmask, %eax
	movq	%rcx, %r10
	syscall
	jc	1b		 /* error: result = -errno */
	testq	%rdx,%rdx		# test if old mask requested
	jz	2f
	movq	%rax,(%rdx)		# store old mask
	xorq	%rax,%rax
2:	ret

	.align 4
	.global _dl_bind_start
	.type _dl_bind_start,@function
_dl_bind_start:
	pushfq				# save registers
	pushq	%rax
	pushq	%rcx
	pushq	%rdx
	pushq	%rsi
	pushq	%rdi
	pushq	%r8
	pushq	%r9
	pushq	%r10
	pushq	%r11

	movq	80(%rsp), %rdi		# Copy of reloff
	movq	88(%rsp), %rsi		# Copy of obj
	call	_dl_bind@PLT		# Call the binder
	movq	%rax,88(%rsp)		# Store function to be called in obj

	popq	%r11			# restore registers
	popq	%r10
	popq	%r9
	popq	%r8
	popq	%rdi
	popq	%rsi
	popq	%rdx
	popq	%rcx
	popq	%rax
	popfq

	leaq	8(%rsp),%rsp		# Discard reloff, do not change eflags
	ret