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
|
/*
* Copyright (c) 2018 Virtuozzo International GmbH
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
*
*/
#include "qemu/osdep.h"
#include "err.h"
#include "qemu_elf.h"
#define QEMU_NOTE_NAME "QEMU"
#ifndef ROUND_UP
#define ROUND_UP(n, d) (((n) + (d) - 1) & -(0 ? (n) : (d)))
#endif
#ifndef DIV_ROUND_UP
#define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
#endif
#define ELF_NOTE_SIZE(hdr_size, name_size, desc_size) \
((DIV_ROUND_UP((hdr_size), 4) + \
DIV_ROUND_UP((name_size), 4) + \
DIV_ROUND_UP((desc_size), 4)) * 4)
int is_system(QEMUCPUState *s)
{
return s->gs.base >> 63;
}
static char *nhdr_get_name(Elf64_Nhdr *nhdr)
{
return (char *)nhdr + ROUND_UP(sizeof(*nhdr), 4);
}
static void *nhdr_get_desc(Elf64_Nhdr *nhdr)
{
return nhdr_get_name(nhdr) + ROUND_UP(nhdr->n_namesz, 4);
}
static Elf64_Nhdr *nhdr_get_next(Elf64_Nhdr *nhdr)
{
return (void *)((uint8_t *)nhdr + ELF_NOTE_SIZE(sizeof(*nhdr),
nhdr->n_namesz, nhdr->n_descsz));
}
Elf64_Phdr *elf64_getphdr(void *map)
{
Elf64_Ehdr *ehdr = map;
Elf64_Phdr *phdr = (void *)((uint8_t *)map + ehdr->e_phoff);
return phdr;
}
Elf64_Half elf_getphdrnum(void *map)
{
Elf64_Ehdr *ehdr = map;
return ehdr->e_phnum;
}
static int init_states(QEMU_Elf *qe)
{
Elf64_Phdr *phdr = elf64_getphdr(qe->map);
Elf64_Nhdr *start = (void *)((uint8_t *)qe->map + phdr[0].p_offset);
Elf64_Nhdr *end = (void *)((uint8_t *)start + phdr[0].p_memsz);
Elf64_Nhdr *nhdr;
size_t cpu_nr = 0;
if (phdr[0].p_type != PT_NOTE) {
eprintf("Failed to find PT_NOTE\n");
return 1;
}
qe->has_kernel_gs_base = 1;
for (nhdr = start; nhdr < end; nhdr = nhdr_get_next(nhdr)) {
if (!strcmp(nhdr_get_name(nhdr), QEMU_NOTE_NAME)) {
QEMUCPUState *state = nhdr_get_desc(nhdr);
if (state->size < sizeof(*state)) {
eprintf("CPU #%zu: QEMU CPU state size %u doesn't match\n",
cpu_nr, state->size);
/*
* We assume either every QEMU CPU state has KERNEL_GS_BASE or
* no one has.
*/
qe->has_kernel_gs_base = 0;
}
cpu_nr++;
}
}
printf("%zu CPU states has been found\n", cpu_nr);
qe->state = malloc(sizeof(*qe->state) * cpu_nr);
if (!qe->state) {
return 1;
}
cpu_nr = 0;
for (nhdr = start; nhdr < end; nhdr = nhdr_get_next(nhdr)) {
if (!strcmp(nhdr_get_name(nhdr), QEMU_NOTE_NAME)) {
qe->state[cpu_nr] = nhdr_get_desc(nhdr);
cpu_nr++;
}
}
qe->state_nr = cpu_nr;
return 0;
}
static void exit_states(QEMU_Elf *qe)
{
free(qe->state);
}
int QEMU_Elf_init(QEMU_Elf *qe, const char *filename)
{
GError *gerr = NULL;
int err = 0;
qe->gmf = g_mapped_file_new(filename, TRUE, &gerr);
if (gerr) {
eprintf("Failed to map ELF dump file \'%s\'\n", filename);
g_error_free(gerr);
return 1;
}
qe->map = g_mapped_file_get_contents(qe->gmf);
qe->size = g_mapped_file_get_length(qe->gmf);
if (init_states(qe)) {
eprintf("Failed to extract QEMU CPU states\n");
err = 1;
goto out_unmap;
}
return 0;
out_unmap:
g_mapped_file_unref(qe->gmf);
return err;
}
void QEMU_Elf_exit(QEMU_Elf *qe)
{
exit_states(qe);
g_mapped_file_unref(qe->gmf);
}
|
