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
|
/*--------------------------------------------------------------------*/
/*--- Support for doing system calls. syscall-ppc64-linux.S ---*/
/*--------------------------------------------------------------------*/
/*
This file is part of Valgrind, a dynamic binary instrumentation
framework.
Copyright (C) 2005-2017 Paul Mackerras <paulus@samba.org>
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
This program 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
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, see <http://www.gnu.org/licenses/>.
The GNU General Public License is contained in the file COPYING.
*/
#include "pub_core_basics_asm.h"
#if defined(VGP_ppc64le_linux)
#include "pub_core_vkiscnums_asm.h"
#include "libvex_guest_offsets.h"
/*----------------------------------------------------------------*/
/*
Perform a syscall for the client. This will run a syscall
with the client's specific per-thread signal mask.
The structure of this function is such that, if the syscall is
interrupted by a signal, we can determine exactly what
execution state we were in with respect to the execution of
the syscall by examining the value of NIP in the signal
handler. This means that we can always do the appropriate
thing to precisely emulate the kernel's signal/syscall
interactions.
The syscall number is taken from the argument, even though it
should also be in regs->m_gpr[0]. The syscall result is written
back to regs->m_gpr[3]/m_xer/m_result on completion.
Returns 0 if the syscall was successfully called (even if the
syscall itself failed), or a nonzero error code in the lowest
8 bits if one of the sigprocmasks failed (there's no way to
determine which one failed). And there's no obvious way to
recover from that either, but nevertheless we want to know.
VG_(fixup_guest_state_after_syscall_interrupted) does the
thread state fixup in the case where we were interrupted by a
signal.
Prototype:
UWord ML_(do_syscall_for_client_WRK)(
Int syscallno, // r3
void* guest_state, // r4
const vki_sigset_t *sysmask, // r5
const vki_sigset_t *postmask, // r6
Int sigsetSzB) // r7
*/
/* from vki_arch.h */
/* SCV flag defines. Must be consistently defined here and in
coregrind/pub_core_syscall.h,in the do_syscall_WRK() assembly code in
coregrind/m_syscall.c and coregrind/m_syswrap/syscall-ppcle-linux.S code.
*/
#define SC_FLAG 1
#define SCV_FLAG 2
#define VKI_SIG_SETMASK 2
.align 2
.globl ML_(do_syscall_for_client_WRK)
#if _CALL_ELF == 2
.type .ML_(do_syscall_for_client_WRK),@function
ML_(do_syscall_for_client_WRK):
0: addis 2,12,.TOC.-0b@ha
addi 2,2,.TOC.-0b@l
.localentry ML_(do_syscall_for_client_WRK), .-ML_(do_syscall_for_client_WRK)
#else
.section ".opd","aw"
.align 3
ML_(do_syscall_for_client_WRK):
.quad .ML_(do_syscall_for_client_WRK),.TOC.@tocbase,0
.previous
#endif
#if _CALL_ELF == 2
0: addis 2,12,.TOC.-0b@ha
addi 2,2,.TOC.-0b@l
.localentry ML_(do_syscall_for_client_WRK), .-ML_(do_syscall_for_client_WRK)
#endif
.type .ML_(do_syscall_for_client_WRK),@function
.globl .ML_(do_syscall_for_client_WRK)
.ML_(do_syscall_for_client_WRK):
/* make a stack frame */
stdu 1,-80(1)
std 31,72(1)
std 30,64(1)
std 29,56(1)
std 28,48(1)
std 27,40(1) /* save r27 to stack frame */
mflr 27 /* Get link register */
std 27,16(1) /* Save link register */
std 9,32(1) /* save gpr 9 */
mr 31,3 /* syscall number */
mr 30,4 /* guest_state */
mr 29,6 /* postmask */
mr 28,7 /* sigsetSzB */
/* set the signal mask for doing the system call */
/* set up for sigprocmask(SIG_SETMASK, sysmask, postmask) */
1: li 0,__NR_rt_sigprocmask
li 3,VKI_SIG_SETMASK
mr 4,5
mr 5,6
mr 6,7
sc /* set the mask */
bso 7f /* if the sigprocmask fails */
/* load up syscall args from the threadstate */
ld 3,OFFSET_ppc64_GPR3(30)
ld 4,OFFSET_ppc64_GPR4(30)
ld 5,OFFSET_ppc64_GPR5(30)
ld 6,OFFSET_ppc64_GPR6(30)
ld 7,OFFSET_ppc64_GPR7(30)
ld 8,OFFSET_ppc64_GPR8(30)
ld 9,OFFSET_ppc64_GPR9(30) /* get flag for sc or scv inst */
mr 0,31 /* syscall number */
cmpdi 9,SC_FLAG
bne 8f /* jump to scv call if gpr9 != 0 */
/* If you change the code between labels 2 and 3, you need to update
the corresponding ppc64le calculations for blksys_restart and
blksys_complete in function getSyscallArgsFromGuestState in file
syswrap-main.c. */
2: sc /* do the syscall */
b 3f /* jump over scv call */
8: scv 0
/* put the result back in the threadstate */
3: std 3,OFFSET_ppc64_GPR3(30) /* gst->GPR3 = sc result */
/* copy cr0.so back to simulated state */
mfcr 5 /* r5 = CR */
rlwinm 5,5,4,31,31 /* r5 = (CR >> 28) & 1 */
ld 9,OFFSET_ppc64_GPR9(30)
cmpdi 9,SC_FLAG
bne 4f /* scv does not change CR */
stb 5,OFFSET_ppc64_CR0_0(30) /* gst->CR0.SO = cr0.so */
/* block signals again */
/* set up for sigprocmask(SIG_SETMASK, postmask, NULL) */
4: li 0,__NR_rt_sigprocmask
li 3,VKI_SIG_SETMASK
mr 4,29
li 5,0
mr 6,28
sc /* set the mask */
bso 7f /* if the sigprocmask fails */
/* now safe from signals */
li 3,0 /* SUCCESS */
/* pop off stack frame */
5: ld 28,48(1)
ld 29,56(1)
ld 30,64(1)
ld 31,72(1)
ld 9,32(1)
ld 27,16(1) /* Fetch LR from frame */
mtlr 27 /* restore LR */
ld 27,40(1) /* restore r27 from stack frame */
addi 1,1,80
blr
/* failure: return 0x8000 | error code */
7: ori 3,3,0x8000 /* FAILURE -- ensure return value is nonzero */
b 5b
#if _CALL_ELF == 2
.size .ML_(do_syscall_for_client_WRK),.-.ML_(do_syscall_for_client_WRK)
#else
.size .ML_(do_syscall_for_client_WRK),.-.ML_(do_syscall_for_client_WRK)
#endif
.section .rodata
/* export the ranges so that
VG_(fixup_guest_state_after_syscall_interrupted) can do the
right thing */
.globl ML_(blksys_setup)
.globl ML_(blksys_restart)
.globl ML_(blksys_complete)
.globl ML_(blksys_committed)
.globl ML_(blksys_finished)
ML_(blksys_setup): .quad 1b
ML_(blksys_restart): .quad 2b
ML_(blksys_complete): .quad 3b
ML_(blksys_committed): .quad 4b
ML_(blksys_finished): .quad 5b
#endif // defined(VGP_ppc64le_linux)
/* Let the linker know we don't need an executable stack */
MARK_STACK_NO_EXEC
/*--------------------------------------------------------------------*/
/*--- end ---*/
/*--------------------------------------------------------------------*/
|
