summaryrefslogtreecommitdiff
path: root/sysdeps/s390/s390-64/dl-trampoline.S
blob: 6919ed013898ad89ef6d43bca491c1bede6a1c8d (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
/* PLT trampolines.  s390x version.
   Copyright (C) 2005-2016 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/>.  */

/* The PLT stubs will call _dl_runtime_resolve/_dl_runtime_profile
 * with the following linkage:
 *   r2 - r6 : parameter registers
 *   f0, f2, f4, f6 : floating point parameter registers
 *   48(r15), 56(r15) : PLT arguments PLT1, PLT2
 *   160(r15) : additional stack parameters
 * The normal clobber rules for function calls apply:
 *   r0 - r5 : call clobbered
 *   r6 - r13 :	 call saved
 *   r14 : return address (call clobbered)
 *   r15 : stack pointer (call saved)
 *   f1, f3, f5, f7 : call saved
 *   f0 - f3, f5, f7 - f15 : call clobbered
 */

#include <sysdep.h>

	.text
	.globl _dl_runtime_resolve
	.type _dl_runtime_resolve, @function
	cfi_startproc
	.align 16
_dl_runtime_resolve:
	stmg   %r2,%r5,64(15)	# save call-clobbered argument registers
	stg    %r14,96(15)
	cfi_offset (r14, -64)
	lgr    %r0,%r15
	aghi   %r15,-160	# create stack frame
	cfi_adjust_cfa_offset (160)
	stg    %r0,0(%r15)      # write backchain
	lmg    %r2,%r3,208(%r15)# load args saved by PLT
	brasl  %r14,_dl_fixup	# call fixup
	lgr    %r1,%r2		# function addr returned in r2
	aghi   %r15,160		# remove stack frame
	cfi_adjust_cfa_offset (-160)
	lg     %r14,96(15)	# restore registers
	lmg    %r2,%r5,64(15)
	br     %r1
	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:
	stmg   %r2,%r6,64(%r15)		# save call-clobbered arg regs
	std    %f0,104(%r15)		# + r6 needed as arg for
	std    %f2,112(%r15)		#  _dl_profile_fixup
	std    %f4,120(%r15)
	std    %f6,128(%r15)
	stg    %r12,24(%r15)		# r12 is used as backup of r15
	stg    %r14,32(%r15)
	cfi_offset (r6, -96)
	cfi_offset (f0, -56)
	cfi_offset (f2, -48)
	cfi_offset (f4, -40)
	cfi_offset (f6, -32)
	cfi_offset (r12, -136)
	cfi_offset (r14, -128)
	lgr    %r12,%r15		# backup stack pointer
	cfi_def_cfa_register (12)
	aghi   %r15,-160		# create stack frame
	stg    %r12,0(%r15)		# save backchain
	lmg    %r2,%r3,48(%r12)		# load arguments saved by PLT
	lgr    %r4,%r14			# return address as third parameter
	la     %r5,64(%r12)		# pointer to struct La_s390_32_regs
	la     %r6,40(%r12)		# long int * framesize
	brasl  %r14,_dl_profile_fixup	# call resolver
	lgr    %r1,%r2			# function addr returned in r2
	lg     %r0,40(%r12)		# load framesize
	ltgr   %r0,%r0
	jnm    1f

	lmg    %r2,%r6,64(%r12)		# framesize < 0 means no pltexit call
	ld     %f0,104(%r12)		# so we can do a tail call without
	ld     %f2,112(%r12)		# copying the arg overflow area
	ld     %f4,120(%r12)
	ld     %f6,128(%r12)

	lgr    %r15,%r12		# remove stack frame
	cfi_def_cfa_register (15)
	lg     %r14,32(%r15)		# restore registers
	lg     %r12,24(%r15)
	br     %r1			# tail-call to resolved function

	cfi_def_cfa_register (12)
1:	jz     4f			# framesize == 0 ?
	aghi   %r0,7			# align framesize to 8
	nill   %r0,0xfff8
	slgr   %r15,%r0			# make room for framesize bytes
	stg    %r12,0(%r15)
	la     %r2,160(%r15)
	la     %r3,160(%r12)
	srlg   %r0,%r0,3
3:	mvc    0(8,%r2),0(%r3)		# copy additional parameters
	la     %r2,8(%r2)
	la     %r3,8(%r3)
	brctg  %r0,3b
4:	lmg    %r2,%r6,64(%r12)		# load register parameters
	ld     %f0,104(%r12)            # restore call-clobbered arg regs
	ld     %f2,112(%r12)
	ld     %f4,120(%r12)
	ld     %f6,128(%r12)
	basr   %r14,%r1			# call resolved function
	stg    %r2,136(%r12)
	std    %f0,144(%r12)
	lmg    %r2,%r3,48(%r12)		# load arguments saved by PLT
	la     %r4,32(%r12)		# pointer to struct La_s390_32_regs
	la     %r5,72(%r12)		# pointer to struct La_s390_32_retval
	brasl  %r14,_dl_call_pltexit

	lgr    %r15,%r12		# remove stack frame
	cfi_def_cfa_register (15)
	lg     %r14,32(%r15)		# restore registers
	lg     %r12,24(%r15)
	br     %r14

	cfi_endproc
	.size _dl_runtime_profile, .-_dl_runtime_profile
#endif