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
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
|
/*
* ARM64 crashdump.
* partly derived from arm implementation
*
* Copyright (c) 2014-2017 Linaro Limited
* Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#define _GNU_SOURCE
#include <errno.h>
#include <linux/elf.h>
#include "kexec.h"
#include "crashdump.h"
#include "crashdump-arm64.h"
#include "iomem.h"
#include "kexec-arm64.h"
#include "kexec-elf.h"
#include "mem_regions.h"
/* memory ranges of crashed kernel */
static struct memory_ranges system_memory_rgns;
/* memory range reserved for crashkernel */
struct memory_range crash_reserved_mem[CRASH_MAX_RESERVED_RANGES];
struct memory_ranges usablemem_rgns = {
.size = 0,
.max_size = CRASH_MAX_RESERVED_RANGES,
.ranges = crash_reserved_mem,
};
struct memory_range elfcorehdr_mem;
static struct crash_elf_info elf_info = {
.class = ELFCLASS64,
#if (__BYTE_ORDER == __LITTLE_ENDIAN)
.data = ELFDATA2LSB,
#else
.data = ELFDATA2MSB,
#endif
.machine = EM_AARCH64,
};
/*
* iomem_range_callback() - callback called for each iomem region
* @data: not used
* @nr: not used
* @str: name of the memory region
* @base: start address of the memory region
* @length: size of the memory region
*
* This function is called once for each memory region found in /proc/iomem.
* It locates system RAM and crashkernel reserved memory and places these to
* variables, respectively, system_memory_rgns and usablemem_rgns.
*/
static int iomem_range_callback(void *UNUSED(data), int UNUSED(nr),
char *str, unsigned long long base,
unsigned long long length)
{
if (strncmp(str, CRASH_KERNEL, strlen(CRASH_KERNEL)) == 0)
return mem_regions_alloc_and_add(&usablemem_rgns,
base, length, RANGE_RAM);
else if (strncmp(str, SYSTEM_RAM, strlen(SYSTEM_RAM)) == 0)
return mem_regions_alloc_and_add(&system_memory_rgns,
base, length, RANGE_RAM);
else if (strncmp(str, KERNEL_CODE, strlen(KERNEL_CODE)) == 0) {
unsigned long long kva_text = get_kernel_sym("_text");
unsigned long long kva_stext = get_kernel_sym("_stext");
unsigned long long kva_text_end = get_kernel_sym("__init_begin");
/*
* old: kernel_code.start = __pa_symbol(_text);
* new: kernel_code.start = __pa_symbol(_stext);
*
* For compatibility, deduce by comparing the gap "__init_begin - _stext"
* and the res size of "Kernel code" in /proc/iomem
*/
if (kva_text_end - kva_stext == length)
elf_info.kern_paddr_start = base - (kva_stext - kva_text);
else
elf_info.kern_paddr_start = base;
}
else if (strncmp(str, KERNEL_DATA, strlen(KERNEL_DATA)) == 0)
elf_info.kern_size = base + length - elf_info.kern_paddr_start;
return 0;
}
int is_crashkernel_mem_reserved(void)
{
if (!usablemem_rgns.size)
kexec_iomem_for_each_line(NULL, iomem_range_callback, NULL);
return usablemem_rgns.size;
}
/*
* crash_get_memory_ranges() - read system physical memory
*
* Function reads through system physical memory and stores found memory
* regions in system_memory_ranges.
* Regions are sorted in ascending order.
*
* Returns 0 in case of success and a negative value otherwise.
*/
static int crash_get_memory_ranges(void)
{
int i;
/*
* First read all memory regions that can be considered as
* system memory including the crash area.
*/
if (!usablemem_rgns.size)
kexec_iomem_for_each_line(NULL, iomem_range_callback, NULL);
/* allow one or two regions for crash dump kernel */
if (!usablemem_rgns.size)
return -EINVAL;
dbgprint_mem_range("Reserved memory range",
usablemem_rgns.ranges, usablemem_rgns.size);
for (i = 0; i < usablemem_rgns.size; i++) {
if (mem_regions_alloc_and_exclude(&system_memory_rgns,
&crash_reserved_mem[i])) {
fprintf(stderr, "Cannot allocate memory for ranges\n");
return -ENOMEM;
}
}
/*
* Make sure that the memory regions are sorted.
*/
mem_regions_sort(&system_memory_rgns);
dbgprint_mem_range("Coredump memory ranges",
system_memory_rgns.ranges, system_memory_rgns.size);
/*
* For additional kernel code/data segment.
* kern_paddr_start/kern_size are determined in iomem_range_callback
*/
elf_info.kern_vaddr_start = get_kernel_sym("_text");
if (!elf_info.kern_vaddr_start)
elf_info.kern_vaddr_start = UINT64_MAX;
return 0;
}
/*
* load_crashdump_segments() - load the elf core header
* @info: kexec info structure
*
* This function creates and loads an additional segment of elf core header
: which is used to construct /proc/vmcore on crash dump kernel.
*
* Return 0 in case of success and -1 in case of error.
*/
int load_crashdump_segments(struct kexec_info *info)
{
unsigned long elfcorehdr;
unsigned long bufsz;
void *buf;
int err;
/*
* First fetch all the memory (RAM) ranges that we are going to
* pass to the crash dump kernel during panic.
*/
err = crash_get_memory_ranges();
if (err)
return EFAILED;
get_page_offset((unsigned long *)&elf_info.page_offset);
dbgprintf("%s: page_offset: %016llx\n", __func__,
elf_info.page_offset);
err = crash_create_elf64_headers(info, &elf_info,
system_memory_rgns.ranges, system_memory_rgns.size,
&buf, &bufsz, ELF_CORE_HEADER_ALIGN);
if (err)
return EFAILED;
elfcorehdr = add_buffer_phys_virt(info, buf, bufsz, bufsz, 0,
crash_reserved_mem[usablemem_rgns.size - 1].start,
crash_reserved_mem[usablemem_rgns.size - 1].end,
-1, 0);
elfcorehdr_mem.start = elfcorehdr;
elfcorehdr_mem.end = elfcorehdr + bufsz - 1;
dbgprintf("%s: elfcorehdr 0x%llx-0x%llx\n", __func__,
elfcorehdr_mem.start, elfcorehdr_mem.end);
return 0;
}
/*
* e_entry and p_paddr are actually in virtual address space.
* Those values will be translated to physcal addresses by using
* virt_to_phys() in add_segment().
* So let's fix up those values for later use so the memory base
* (arm64_mm.phys_offset) will be correctly replaced with
* crash_reserved_mem[usablemem_rgns.size - 1].start.
*/
void fixup_elf_addrs(struct mem_ehdr *ehdr)
{
struct mem_phdr *phdr;
int i;
ehdr->e_entry += -arm64_mem.phys_offset +
crash_reserved_mem[usablemem_rgns.size - 1].start;
for (i = 0; i < ehdr->e_phnum; i++) {
phdr = &ehdr->e_phdr[i];
if (phdr->p_type != PT_LOAD)
continue;
phdr->p_paddr +=
(-arm64_mem.phys_offset +
crash_reserved_mem[usablemem_rgns.size - 1].start);
}
}
int get_crash_kernel_load_range(uint64_t *start, uint64_t *end)
{
if (!usablemem_rgns.size)
kexec_iomem_for_each_line(NULL, iomem_range_callback, NULL);
if (!usablemem_rgns.size)
return -1;
*start = crash_reserved_mem[usablemem_rgns.size - 1].start;
*end = crash_reserved_mem[usablemem_rgns.size - 1].end;
return 0;
}
|
