summaryrefslogtreecommitdiff
path: root/sysdeps/i386/dl-trampoline.S
blob: 6e7f3aef921fc3e39bd98e2c27878c38af8aeeaa (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
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
/* PLT trampolines.  i386 version.
   Copyright (C) 2004-2017 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
   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/>.  */

#include <sysdep.h>
#include <link-defines.h>

#ifdef HAVE_MPX_SUPPORT
# define PRESERVE_BND_REGS_PREFIX bnd
#else
# define PRESERVE_BND_REGS_PREFIX .byte 0xf2
#endif

	.text
	.globl _dl_runtime_resolve
	.type _dl_runtime_resolve, @function
	cfi_startproc
	.align 16
_dl_runtime_resolve:
	cfi_adjust_cfa_offset (8)
	pushl %eax		# Preserve registers otherwise clobbered.
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %edx
	cfi_adjust_cfa_offset (4)
	movl 16(%esp), %edx	# Copy args pushed by PLT in register.  Note
	movl 12(%esp), %eax	# that `fixup' takes its parameters in regs.
	call _dl_fixup		# Call resolver.
	popl %edx		# Get register content back.
	cfi_adjust_cfa_offset (-4)
	movl (%esp), %ecx
	movl %eax, (%esp)	# Store the function address.
	movl 4(%esp), %eax
	ret $12			# Jump to function address.
	cfi_endproc
	.size _dl_runtime_resolve, .-_dl_runtime_resolve


#ifndef PROF
	.globl _dl_runtime_profile
	.type _dl_runtime_profile, @function
	cfi_startproc
	.align 16
_dl_runtime_profile:
	cfi_adjust_cfa_offset (8)
	pushl %esp
	cfi_adjust_cfa_offset (4)
	addl $8, (%esp)		# Account for the pushed PLT data
	pushl %ebp
	cfi_adjust_cfa_offset (4)
	pushl %eax		# Preserve registers otherwise clobbered.
	cfi_adjust_cfa_offset (4)
	pushl %ecx
	cfi_adjust_cfa_offset (4)
	pushl %edx
	cfi_adjust_cfa_offset (4)
	movl %esp, %ecx
	subl $8, %esp
	cfi_adjust_cfa_offset (8)
	movl $-1, 4(%esp)
	leal 4(%esp), %edx
	movl %edx, (%esp)
	pushl %ecx		# Address of the register structure
	cfi_adjust_cfa_offset (4)
	movl 40(%esp), %ecx	# Load return address
	movl 36(%esp), %edx	# Copy args pushed by PLT in register.  Note
	movl 32(%esp), %eax	# that `fixup' takes its parameters in regs.
	call _dl_profile_fixup	# Call resolver.
	cfi_adjust_cfa_offset (-8)
	movl (%esp), %edx
	testl %edx, %edx
	jns 1f
	popl %edx
	cfi_adjust_cfa_offset (-4)
	popl %edx		# Get register content back.
	cfi_adjust_cfa_offset (-4)
	movl (%esp), %ecx
	movl %eax, (%esp)	# Store the function address.
	movl 4(%esp), %eax
	ret $20			# Jump to function address.

	/*
	    +32     return address
	    +28     PLT1
	    +24     PLT2
	    +20     %esp
	    +16     %ebp
	    +12     %eax
	    +8      %ecx
	    +4      %edx
	   %esp     free
	*/
	cfi_adjust_cfa_offset (8)
1:	movl %ebx, (%esp)
	cfi_rel_offset (ebx, 0)
	movl %edx, %ebx		# This is the frame buffer size
	pushl %edi
	cfi_adjust_cfa_offset (4)
	cfi_rel_offset (edi, 0)
	pushl %esi
	cfi_adjust_cfa_offset (4)
	cfi_rel_offset (esi, 0)
	leal 44(%esp), %esi
	movl %ebx, %ecx
	orl $4, %ebx		# Increase frame size if necessary to align
				# stack for the function call
	andl $~3, %ebx
	movl %esp, %edi
	subl %ebx, %edi
	movl %esp, %ebx
	cfi_def_cfa_register (ebx)
	movl %edi, %esp
	shrl $2, %ecx
	rep
	movsl
	movl (%ebx), %esi
	cfi_restore (esi)
	movl 4(%ebx), %edi
	cfi_restore (edi)
	/*
	   %ebx+40  return address
	   %ebx+36  PLT1
	   %ebx+32  PLT2
	   %ebx+28  %esp
	   %ebx+24  %ebp
	   %ebx+20  %eax
	   %ebx+16  %ecx
	   %ebx+12  %edx
	   %ebx+8   %ebx
	   %ebx+4   free
	   %ebx     free
	   %esp     copied stack frame
	*/
	movl %eax, (%ebx)
	movl 12(%ebx), %edx
	movl 16(%ebx), %ecx
	movl 20(%ebx), %eax
	call *(%ebx)
	movl %ebx, %esp
	cfi_def_cfa_register (esp)
	movl 8(%esp), %ebx
	cfi_restore (ebx)
	/*
	    +40     return address
	    +36     PLT1
	    +32     PLT2
	    +28     %esp
	    +24     %ebp
	    +20     %eax
	    +16     %ecx
	    +12     %edx
	    +8      free
	    +4      free
	   %esp     free
	*/
#if LONG_DOUBLE_SIZE != 12
# error "long double size must be 12 bytes"
#endif
	# Allocate space for La_i86_retval and subtract 12 free bytes.
	subl $(LRV_SIZE - 12), %esp
	cfi_adjust_cfa_offset (LRV_SIZE - 12)
	movl %eax, LRV_EAX_OFFSET(%esp)
	movl %edx, LRV_EDX_OFFSET(%esp)
	fstpt LRV_ST0_OFFSET(%esp)
	fstpt LRV_ST1_OFFSET(%esp)
#ifdef HAVE_MPX_SUPPORT
	bndmov %bnd0, LRV_BND0_OFFSET(%esp)
	bndmov %bnd1, LRV_BND1_OFFSET(%esp)
#else
	.byte 0x66,0x0f,0x1b,0x44,0x24,LRV_BND0_OFFSET
	.byte 0x66,0x0f,0x1b,0x4c,0x24,LRV_BND1_OFFSET
#endif
	pushl %esp
	cfi_adjust_cfa_offset (4)
	# Address of La_i86_regs area.
	leal (LRV_SIZE + 4)(%esp), %ecx
	# PLT2
	movl (LRV_SIZE + 4 + LR_SIZE)(%esp), %eax
	# PLT1
	movl (LRV_SIZE + 4 + LR_SIZE + 4)(%esp), %edx
	call _dl_call_pltexit
	movl LRV_EAX_OFFSET(%esp), %eax
	movl LRV_EDX_OFFSET(%esp), %edx
	fldt LRV_ST1_OFFSET(%esp)
	fldt LRV_ST0_OFFSET(%esp)
#ifdef HAVE_MPX_SUPPORT
	bndmov LRV_BND0_OFFSET(%esp), %bnd0
	bndmov LRV_BND1_OFFSET(%esp), %bnd1
#else
	.byte 0x66,0x0f,0x1a,0x44,0x24,LRV_BND0_OFFSET
	.byte 0x66,0x0f,0x1a,0x4c,0x24,LRV_BND1_OFFSET
#endif
	# Restore stack before return.
	addl $(LRV_SIZE + 4 + LR_SIZE + 4), %esp
	cfi_adjust_cfa_offset (-(LRV_SIZE + 4 + LR_SIZE + 4))
	PRESERVE_BND_REGS_PREFIX
	ret
	cfi_endproc
	.size _dl_runtime_profile, .-_dl_runtime_profile
#endif