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
|
/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1995 - 2000, 2001 by Ralf Baechle
* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
* Copyright (C) 2001 MIPS Technologies, Inc.
* Copyright (C) 2004 Thiemo Seufer
*
* Hairy, the userspace application uses a different argument passing
* convention than the kernel, so we have to translate things from o32
* to ABI64 calling convention. 64-bit syscalls are also processed
* here for now.
*/
#include <linux/errno.h>
#include <asm/asm.h>
#include <asm/asmmacro.h>
#include <asm/irqflags.h>
#include <asm/mipsregs.h>
#include <asm/regdef.h>
#include <asm/stackframe.h>
#include <asm/thread_info.h>
#include <asm/unistd.h>
#include <asm/sysmips.h>
.align 5
NESTED(handle_sys, PT_SIZE, sp)
.set noat
SAVE_SOME
TRACE_IRQS_ON_RELOAD
STI
.set at
ld t1, PT_EPC(sp) # skip syscall on return
dsubu t0, v0, __NR_O32_Linux # check syscall number
sltiu t0, t0, __NR_O32_Linux_syscalls
daddiu t1, 4 # skip to next instruction
sd t1, PT_EPC(sp)
beqz t0, not_o32_scall
#if 0
SAVE_ALL
move a1, v0
PRINT("Scall %ld\n")
RESTORE_ALL
#endif
/* We don't want to stumble over broken sign extensions from
userland. O32 does never use the upper half. */
sll a0, a0, 0
sll a1, a1, 0
sll a2, a2, 0
sll a3, a3, 0
sd a3, PT_R26(sp) # save a3 for syscall restarting
/*
* More than four arguments. Try to deal with it by copying the
* stack arguments from the user stack to the kernel stack.
* This Sucks (TM).
*
* We intentionally keep the kernel stack a little below the top of
* userspace so we don't have to do a slower byte accurate check here.
*/
ld t0, PT_R29(sp) # get old user stack pointer
daddu t1, t0, 32
bltz t1, bad_stack
load_a4: lw a4, 16(t0) # argument #5 from usp
load_a5: lw a5, 20(t0) # argument #6 from usp
load_a6: lw a6, 24(t0) # argument #7 from usp
load_a7: lw a7, 28(t0) # argument #8 from usp
loads_done:
.section __ex_table,"a"
PTR load_a4, bad_stack_a4
PTR load_a5, bad_stack_a5
PTR load_a6, bad_stack_a6
PTR load_a7, bad_stack_a7
.previous
li t1, _TIF_WORK_SYSCALL_ENTRY
LONG_L t0, TI_FLAGS($28) # syscall tracing enabled?
and t0, t1, t0
bnez t0, trace_a_syscall
syscall_common:
dsll t0, v0, 3 # offset into table
ld t2, (sys32_call_table - (__NR_O32_Linux * 8))(t0)
jalr t2 # Do The Real Thing (TM)
li t0, -EMAXERRNO - 1 # error?
sltu t0, t0, v0
sd t0, PT_R7(sp) # set error flag
beqz t0, 1f
ld t1, PT_R2(sp) # syscall number
dnegu v0 # error
sd t1, PT_R0(sp) # save it for syscall restarting
1: sd v0, PT_R2(sp) # result
o32_syscall_exit:
j syscall_exit_partial
/* ------------------------------------------------------------------------ */
trace_a_syscall:
SAVE_STATIC
sd a4, PT_R8(sp) # Save argument registers
sd a5, PT_R9(sp)
sd a6, PT_R10(sp)
sd a7, PT_R11(sp) # For indirect syscalls
move a0, sp
/*
* absolute syscall number is in v0 unless we called syscall(__NR_###)
* where the real syscall number is in a0
* note: NR_syscall is the first O32 syscall but the macro is
* only defined when compiling with -mabi=32 (CONFIG_32BIT)
* therefore __NR_O32_Linux is used (4000)
*/
.set push
.set reorder
subu t1, v0, __NR_O32_Linux
move a1, v0
bnez t1, 1f /* __NR_syscall at offset 0 */
ld a1, PT_R4(sp) /* Arg1 for __NR_syscall case */
.set pop
1: jal syscall_trace_enter
bltz v0, 1f # seccomp failed? Skip syscall
RESTORE_STATIC
ld v0, PT_R2(sp) # Restore syscall (maybe modified)
ld a0, PT_R4(sp) # Restore argument registers
ld a1, PT_R5(sp)
ld a2, PT_R6(sp)
ld a3, PT_R7(sp)
ld a4, PT_R8(sp)
ld a5, PT_R9(sp)
ld a6, PT_R10(sp)
ld a7, PT_R11(sp) # For indirect syscalls
dsubu t0, v0, __NR_O32_Linux # check (new) syscall number
sltiu t0, t0, __NR_O32_Linux_syscalls
beqz t0, not_o32_scall
j syscall_common
1: j syscall_exit
/* ------------------------------------------------------------------------ */
/*
* The stackpointer for a call with more than 4 arguments is bad.
*/
bad_stack:
li v0, EFAULT
sd v0, PT_R2(sp)
li t0, 1 # set error flag
sd t0, PT_R7(sp)
j o32_syscall_exit
bad_stack_a4:
li a4, 0
b load_a5
bad_stack_a5:
li a5, 0
b load_a6
bad_stack_a6:
li a6, 0
b load_a7
bad_stack_a7:
li a7, 0
b loads_done
not_o32_scall:
/*
* This is not an o32 compatibility syscall, pass it on
* to the 64-bit syscall handlers.
*/
#ifdef CONFIG_MIPS32_N32
j handle_sysn32
#else
j handle_sys64
#endif
END(handle_sys)
LEAF(sys32_syscall)
subu t0, a0, __NR_O32_Linux # check syscall number
sltiu v0, t0, __NR_O32_Linux_syscalls
beqz t0, einval # do not recurse
dsll t1, t0, 3
beqz v0, einval
ld t2, sys32_call_table(t1) # syscall routine
move a0, a1 # shift argument registers
move a1, a2
move a2, a3
move a3, a4
move a4, a5
move a5, a6
move a6, a7
jr t2
/* Unreached */
einval: li v0, -ENOSYS
jr ra
END(sys32_syscall)
#define __SYSCALL(nr, entry, nargs) PTR entry
.align 3
.type sys32_call_table,@object
EXPORT(sys32_call_table)
#include <asm/syscall_table_64_o32.h>
#undef __SYSCALL
|
