aboutsummaryrefslogtreecommitdiff
path: root/sysdeps/x86_64/dl-trampoline.S
blob: 0ae47a47db2ad1381a4e1765500c3bdeda84a181 (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
216
217
218
219
220
221
/* PLT trampolines.  x86-64 version.
   Copyright (C) 2004, 2005, 2007, 2009 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, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include <sysdep.h>

	.text
	.globl _dl_runtime_resolve
	.type _dl_runtime_resolve, @function
	.align 16
	cfi_startproc
_dl_runtime_resolve:
	subq $56,%rsp
	cfi_adjust_cfa_offset(72) # Incorporate PLT
	movq %rax,(%rsp)	# Preserve registers otherwise clobbered.
	movq %rcx, 8(%rsp)
	movq %rdx, 16(%rsp)
	movq %rsi, 24(%rsp)
	movq %rdi, 32(%rsp)
	movq %r8, 40(%rsp)
	movq %r9, 48(%rsp)
	movq 64(%rsp), %rsi	# Copy args pushed by PLT in register.
	movq 56(%rsp), %rdi	# %rdi: link_map, %rsi: reloc_offset
	call _dl_fixup		# Call resolver.
	movq %rax, %r11		# Save return value
	movq 48(%rsp), %r9	# Get register content back.
	movq 40(%rsp), %r8
	movq 32(%rsp), %rdi
	movq 24(%rsp), %rsi
	movq 16(%rsp), %rdx
	movq 8(%rsp), %rcx
	movq (%rsp), %rax
	addq $72, %rsp		# Adjust stack(PLT did 2 pushes)
	cfi_adjust_cfa_offset(-72)
	jmp *%r11		# Jump to function address.
	cfi_endproc
	.size _dl_runtime_resolve, .-_dl_runtime_resolve


#ifndef PROF
	.globl _dl_runtime_profile
	.type _dl_runtime_profile, @function
	.align 16
	cfi_startproc

_dl_runtime_profile:
	/* The La_x86_64_regs data structure pointed to by the
	   fourth paramater must be 16-byte aligned.  This must
	   be explicitly enforced.  We have the set up a dynamically
	   sized stack frame.  %rbx points to the top half which
	   has a fixed size and preserves the original stack pointer.  */

	subq $32, %rsp		# Allocate the local storage.
	cfi_adjust_cfa_offset(48) # Incorporate PLT
	movq %rbx, (%rsp)
	cfi_rel_offset(%rbx, 0)

	/* On the stack:
		56(%rbx)	parameter #1
		48(%rbx)	return address

		40(%rbx)	reloc index
		32(%rbx)	link_map

		24(%rbx)	La_x86_64_regs pointer
		16(%rbx)	framesize
		 8(%rbx)	rax
		  (%rbx)	rbx
	*/

	movq %rax, 8(%rsp)
	movq %rsp, %rbx
	cfi_def_cfa_register(%rbx)

	/* Actively align the La_x86_64_regs structure.  */
	andq $0xfffffffffffffff0, %rsp
	subq $192, %rsp		# sizeof(La_x86_64_regs)
	movq %rsp, 24(%rbx)

	movq %rdx,   (%rsp)	# Fill the La_x86_64_regs structure.
	movq %r8,   8(%rsp)
	movq %r9,  16(%rsp)
	movq %rcx, 24(%rsp)
	movq %rsi, 32(%rsp)
	movq %rdi, 40(%rsp)
	movq %rbp, 48(%rsp)
	leaq 48(%rbx), %rax
	movq %rax, 56(%rsp)
	movaps %xmm0,  64(%rsp)
	movaps %xmm1,  80(%rsp)
	movaps %xmm2,  96(%rsp)
	movaps %xmm3, 112(%rsp)
	movaps %xmm4, 128(%rsp)
	movaps %xmm5, 144(%rsp)
	movaps %xmm7, 160(%rsp)

	movq %rsp, %rcx		# La_x86_64_regs pointer to %rcx.
	movq 48(%rbx), %rdx	# Load return address if needed.
	movq 40(%rbx), %rsi	# Copy args pushed by PLT in register.
	movq 32(%rbx), %rdi	# %rdi: link_map, %rsi: reloc_offset
	leaq 16(%rbx), %r8
	call _dl_profile_fixup	# Call resolver.

	movq %rax, %r11		# Save return value.

	movq 8(%rbx), %rax	# Get back register content.
	movq      (%rsp), %rdx
	movq     8(%rsp), %r8
	movq    16(%rsp), %r9
	movaps  64(%rsp), %xmm0
	movaps  80(%rsp), %xmm1
	movaps  96(%rsp), %xmm2
	movaps 112(%rsp), %xmm3
	movaps 128(%rsp), %xmm4
	movaps 144(%rsp), %xmm5
	movaps 160(%rsp), %xmm7

	movq 16(%rbx), %r10	# Anything in framesize?
	testq %r10, %r10
	jns 1f

	/* There's nothing in the frame size, so there
	   will be no call to the _dl_call_pltexit. */

	movq 24(%rsp), %rcx	# Get back registers content.
	movq 32(%rsp), %rsi
	movq 40(%rsp), %rdi

	movq %rbx, %rsp
	movq (%rsp), %rbx
	cfi_restore(rbx)
	cfi_def_cfa_register(%rsp)

	addq $48, %rsp		# Adjust the stack to the return value
				# (eats the reloc index and link_map)
	cfi_adjust_cfa_offset(-48)
	jmp *%r11		# Jump to function address.

1:
	cfi_adjust_cfa_offset(48)
	cfi_rel_offset(%rbx, 0)
	cfi_def_cfa_register(%rbx)

	/* At this point we need to prepare new stack for the function
	   which has to be called.  We copy the original stack to a
	   temporary buffer of the size specified by the 'framesize'
	   returned from _dl_profile_fixup */

	leaq 56(%rbx), %rsi	# stack
	addq $8, %r10
	andq $0xfffffffffffffff0, %r10
	movq %r10, %rcx
	subq %r10, %rsp
	movq %rsp, %rdi
	shrq $3, %rcx
	rep
	movsq

	movq 24(%rdi), %rcx	# Get back register content.
	movq 32(%rdi), %rsi
	movq 40(%rdi), %rdi

	call *%r11

	mov 24(%rbx), %rsp	# Drop the copied stack content

	/* Now we have to prepare the La_x86_64_retval structure for the
	   _dl_call_pltexit.  The La_x86_64_regs is being pointed by rsp now,
	   so we just need to allocate the sizeof(La_x86_64_retval) space on
	   the stack, since the alignment has already been taken care of. */

	subq $80, %rsp		# sizeof(La_x86_64_retval)
	movq %rsp, %rcx		# La_x86_64_retval argument to %rcx.

	movq %rax, (%rcx)	# Fill in the La_x86_64_retval structure.
	movq %rdx, 8(%rcx)
	movaps %xmm0, 16(%rcx)
	movaps %xmm1, 32(%rcx)
	fstpt 48(%rcx)
	fstpt 64(%rcx)

	movq 24(%rbx), %rdx	# La_x86_64_regs argument to %rdx.
	movq 40(%rbx), %rsi	# Copy args pushed by PLT in register.
        movq 32(%rbx), %rdi	# %rdi: link_map, %rsi: reloc_offset
	call _dl_call_pltexit

	movq  (%rsp), %rax	# Restore return registers.
	movq 8(%rsp), %rdx
	movaps 16(%rsp), %xmm0
	movaps 32(%rsp), %xmm1
	fldt 64(%rsp)
	fldt 48(%rsp)

	movq %rbx, %rsp
	movq  (%rsp), %rbx
	cfi_restore(rbx)
	cfi_def_cfa_register(%rsp)

	addq $48, %rsp		# Adjust the stack to the return value
				# (eats the reloc index and link_map)
	cfi_adjust_cfa_offset(-48)
	retq

	cfi_endproc
	.size _dl_runtime_profile, .-_dl_runtime_profile
#endif