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
|
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
*/
#include <stddef.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <sys/mman.h>
#include <init.h>
#include <as-layout.h>
#include <mm_id.h>
#include <os.h>
#include <ptrace_user.h>
#include <registers.h>
#include <skas.h>
#include <sysdep/ptrace.h>
#include <sysdep/stub.h>
extern char batch_syscall_stub[], __syscall_stub_start[];
extern void wait_stub_done(int pid);
static inline unsigned long *check_init_stack(struct mm_id * mm_idp,
unsigned long *stack)
{
if (stack == NULL) {
stack = (unsigned long *) mm_idp->stack + 2;
*stack = 0;
}
return stack;
}
static unsigned long syscall_regs[MAX_REG_NR];
static int __init init_syscall_regs(void)
{
get_safe_registers(syscall_regs, NULL);
syscall_regs[REGS_IP_INDEX] = STUB_CODE +
((unsigned long) batch_syscall_stub -
(unsigned long) __syscall_stub_start);
syscall_regs[REGS_SP_INDEX] = STUB_DATA;
return 0;
}
__initcall(init_syscall_regs);
static inline long do_syscall_stub(struct mm_id * mm_idp, void **addr)
{
int n, i;
long ret, offset;
unsigned long * data;
unsigned long * syscall;
int err, pid = mm_idp->u.pid;
n = ptrace_setregs(pid, syscall_regs);
if (n < 0) {
printk(UM_KERN_ERR "Registers - \n");
for (i = 0; i < MAX_REG_NR; i++)
printk(UM_KERN_ERR "\t%d\t0x%lx\n", i, syscall_regs[i]);
panic("%s : PTRACE_SETREGS failed, errno = %d\n",
__func__, -n);
}
err = ptrace(PTRACE_CONT, pid, 0, 0);
if (err)
panic("Failed to continue stub, pid = %d, errno = %d\n", pid,
errno);
wait_stub_done(pid);
/*
* When the stub stops, we find the following values on the
* beginning of the stack:
* (long )return_value
* (long )offset to failed sycall-data (0, if no error)
*/
ret = *((unsigned long *) mm_idp->stack);
offset = *((unsigned long *) mm_idp->stack + 1);
if (offset) {
data = (unsigned long *)(mm_idp->stack + offset - STUB_DATA);
printk(UM_KERN_ERR "%s : ret = %ld, offset = %ld, data = %p\n",
__func__, ret, offset, data);
syscall = (unsigned long *)((unsigned long)data + data[0]);
printk(UM_KERN_ERR "%s: syscall %ld failed, return value = 0x%lx, expected return value = 0x%lx\n",
__func__, syscall[0], ret, syscall[7]);
printk(UM_KERN_ERR " syscall parameters: 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
syscall[1], syscall[2], syscall[3],
syscall[4], syscall[5], syscall[6]);
for (n = 1; n < data[0]/sizeof(long); n++) {
if (n == 1)
printk(UM_KERN_ERR " additional syscall data:");
if (n % 4 == 1)
printk("\n" UM_KERN_ERR " ");
printk(" 0x%lx", data[n]);
}
if (n > 1)
printk("\n");
}
else ret = 0;
*addr = check_init_stack(mm_idp, NULL);
return ret;
}
long run_syscall_stub(struct mm_id * mm_idp, int syscall,
unsigned long *args, long expected, void **addr,
int done)
{
unsigned long *stack = check_init_stack(mm_idp, *addr);
*stack += sizeof(long);
stack += *stack / sizeof(long);
*stack++ = syscall;
*stack++ = args[0];
*stack++ = args[1];
*stack++ = args[2];
*stack++ = args[3];
*stack++ = args[4];
*stack++ = args[5];
*stack++ = expected;
*stack = 0;
if (!done && ((((unsigned long) stack) & ~UM_KERN_PAGE_MASK) <
UM_KERN_PAGE_SIZE - 10 * sizeof(long))) {
*addr = stack;
return 0;
}
return do_syscall_stub(mm_idp, addr);
}
long syscall_stub_data(struct mm_id * mm_idp,
unsigned long *data, int data_count,
void **addr, void **stub_addr)
{
unsigned long *stack;
int ret = 0;
/*
* If *addr still is uninitialized, it *must* contain NULL.
* Thus in this case do_syscall_stub correctly won't be called.
*/
if ((((unsigned long) *addr) & ~UM_KERN_PAGE_MASK) >=
UM_KERN_PAGE_SIZE - (10 + data_count) * sizeof(long)) {
ret = do_syscall_stub(mm_idp, addr);
/* in case of error, don't overwrite data on stack */
if (ret)
return ret;
}
stack = check_init_stack(mm_idp, *addr);
*addr = stack;
*stack = data_count * sizeof(long);
memcpy(stack + 1, data, data_count * sizeof(long));
*stub_addr = (void *)(((unsigned long)(stack + 1) &
~UM_KERN_PAGE_MASK) + STUB_DATA);
return 0;
}
int map(struct mm_id * mm_idp, unsigned long virt, unsigned long len, int prot,
int phys_fd, unsigned long long offset, int done, void **data)
{
int ret;
unsigned long args[] = { virt, len, prot,
MAP_SHARED | MAP_FIXED, phys_fd,
MMAP_OFFSET(offset) };
ret = run_syscall_stub(mm_idp, STUB_MMAP_NR, args, virt,
data, done);
return ret;
}
int unmap(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
int done, void **data)
{
int ret;
unsigned long args[] = { (unsigned long) addr, len, 0, 0, 0,
0 };
ret = run_syscall_stub(mm_idp, __NR_munmap, args, 0,
data, done);
return ret;
}
int protect(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
unsigned int prot, int done, void **data)
{
int ret;
unsigned long args[] = { addr, len, prot, 0, 0, 0 };
ret = run_syscall_stub(mm_idp, __NR_mprotect, args, 0,
data, done);
return ret;
}
|
