1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * crash.c - kernel crash support code.
4 * Copyright (C) 2002-2004 Eric Biederman <ebiederm@xmission.com>
5 */
6
7#include <linux/buildid.h>
8#include <linux/init.h>
9#include <linux/utsname.h>
10#include <linux/vmalloc.h>
11#include <linux/sizes.h>
12#include <linux/kexec.h>
13#include <linux/memory.h>
14#include <linux/cpuhotplug.h>
15#include <linux/memblock.h>
16#include <linux/kmemleak.h>
17
18#include <asm/page.h>
19#include <asm/sections.h>
20
21#include <crypto/sha1.h>
22
23#include "kallsyms_internal.h"
24#include "kexec_internal.h"
25
26/* vmcoreinfo stuff */
27unsigned char *vmcoreinfo_data;
28size_t vmcoreinfo_size;
29u32 *vmcoreinfo_note;
30
31/* trusted vmcoreinfo, e.g. we can make a copy in the crash memory */
32static unsigned char *vmcoreinfo_data_safecopy;
33
34struct hwerr_info {
35 atomic_t count;
36 time64_t timestamp;
37};
38
39/*
40 * The hwerr_data[] array is declared with global scope so that it remains
41 * accessible to vmcoreinfo even when Link Time Optimization (LTO) is enabled.
42 */
43struct hwerr_info hwerr_data[HWERR_RECOV_MAX];
44
45Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type,
46 void *data, size_t data_len)
47{
48 struct elf_note *note = (struct elf_note *)buf;
49
50 note->n_namesz = strlen(name) + 1;
51 note->n_descsz = data_len;
52 note->n_type = type;
53 buf += DIV_ROUND_UP(sizeof(*note), sizeof(Elf_Word));
54 memcpy(buf, name, note->n_namesz);
55 buf += DIV_ROUND_UP(note->n_namesz, sizeof(Elf_Word));
56 memcpy(buf, data, data_len);
57 buf += DIV_ROUND_UP(data_len, sizeof(Elf_Word));
58
59 return buf;
60}
61
62void final_note(Elf_Word *buf)
63{
64 memset(buf, 0, sizeof(struct elf_note));
65}
66
67static void update_vmcoreinfo_note(void)
68{
69 u32 *buf = vmcoreinfo_note;
70
71 if (!vmcoreinfo_size)
72 return;
73 buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, type: 0, data: vmcoreinfo_data,
74 data_len: vmcoreinfo_size);
75 final_note(buf);
76}
77
78void crash_update_vmcoreinfo_safecopy(void *ptr)
79{
80 if (ptr)
81 memcpy(ptr, vmcoreinfo_data, vmcoreinfo_size);
82
83 vmcoreinfo_data_safecopy = ptr;
84}
85
86void crash_save_vmcoreinfo(void)
87{
88 if (!vmcoreinfo_note)
89 return;
90
91 /* Use the safe copy to generate vmcoreinfo note if have */
92 if (vmcoreinfo_data_safecopy)
93 vmcoreinfo_data = vmcoreinfo_data_safecopy;
94
95 vmcoreinfo_append_str(fmt: "CRASHTIME=%lld\n", ktime_get_real_seconds());
96 update_vmcoreinfo_note();
97}
98
99void vmcoreinfo_append_str(const char *fmt, ...)
100{
101 va_list args;
102 char buf[0x50];
103 size_t r;
104
105 va_start(args, fmt);
106 r = vscnprintf(buf, size: sizeof(buf), fmt, args);
107 va_end(args);
108
109 r = min(r, (size_t)VMCOREINFO_BYTES - vmcoreinfo_size);
110
111 memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r);
112
113 vmcoreinfo_size += r;
114
115 WARN_ONCE(vmcoreinfo_size == VMCOREINFO_BYTES,
116 "vmcoreinfo data exceeds allocated size, truncating");
117}
118
119/*
120 * provide an empty default implementation here -- architecture
121 * code may override this
122 */
123void __weak arch_crash_save_vmcoreinfo(void)
124{}
125
126phys_addr_t __weak paddr_vmcoreinfo_note(void)
127{
128 return __pa(vmcoreinfo_note);
129}
130EXPORT_SYMBOL(paddr_vmcoreinfo_note);
131
132void hwerr_log_error_type(enum hwerr_error_type src)
133{
134 if (src < 0 || src >= HWERR_RECOV_MAX)
135 return;
136
137 atomic_inc(v: &hwerr_data[src].count);
138 WRITE_ONCE(hwerr_data[src].timestamp, ktime_get_real_seconds());
139}
140EXPORT_SYMBOL_GPL(hwerr_log_error_type);
141
142static int __init crash_save_vmcoreinfo_init(void)
143{
144 vmcoreinfo_data = (unsigned char *)get_zeroed_page(GFP_KERNEL);
145 if (!vmcoreinfo_data) {
146 pr_warn("Memory allocation for vmcoreinfo_data failed\n");
147 return -ENOMEM;
148 }
149
150 vmcoreinfo_note = alloc_pages_exact(VMCOREINFO_NOTE_SIZE,
151 GFP_KERNEL | __GFP_ZERO);
152 if (!vmcoreinfo_note) {
153 free_page((unsigned long)vmcoreinfo_data);
154 vmcoreinfo_data = NULL;
155 pr_warn("Memory allocation for vmcoreinfo_note failed\n");
156 return -ENOMEM;
157 }
158
159 VMCOREINFO_OSRELEASE(init_uts_ns.name.release);
160 VMCOREINFO_BUILD_ID();
161 VMCOREINFO_PAGESIZE(PAGE_SIZE);
162
163 VMCOREINFO_SYMBOL(init_uts_ns);
164 VMCOREINFO_OFFSET(uts_namespace, name);
165 VMCOREINFO_SYMBOL(node_online_map);
166#ifdef CONFIG_MMU
167 VMCOREINFO_SYMBOL_ARRAY(swapper_pg_dir);
168#endif
169 VMCOREINFO_SYMBOL(_stext);
170 vmcoreinfo_append_str(fmt: "NUMBER(VMALLOC_START)=0x%lx\n", (unsigned long) VMALLOC_START);
171
172#ifndef CONFIG_NUMA
173 VMCOREINFO_SYMBOL(mem_map);
174 VMCOREINFO_SYMBOL(contig_page_data);
175#endif
176#ifdef CONFIG_SPARSEMEM_VMEMMAP
177 VMCOREINFO_SYMBOL_ARRAY(vmemmap);
178#endif
179#ifdef CONFIG_SPARSEMEM
180 VMCOREINFO_SYMBOL_ARRAY(mem_section);
181 VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
182 VMCOREINFO_STRUCT_SIZE(mem_section);
183 VMCOREINFO_OFFSET(mem_section, section_mem_map);
184 VMCOREINFO_NUMBER(SECTION_SIZE_BITS);
185 VMCOREINFO_NUMBER(MAX_PHYSMEM_BITS);
186#endif
187 VMCOREINFO_STRUCT_SIZE(page);
188 VMCOREINFO_STRUCT_SIZE(pglist_data);
189 VMCOREINFO_STRUCT_SIZE(zone);
190 VMCOREINFO_STRUCT_SIZE(free_area);
191 VMCOREINFO_STRUCT_SIZE(list_head);
192 VMCOREINFO_SIZE(nodemask_t);
193 VMCOREINFO_OFFSET(page, flags);
194 VMCOREINFO_OFFSET(page, _refcount);
195 VMCOREINFO_OFFSET(page, mapping);
196 VMCOREINFO_OFFSET(page, lru);
197 VMCOREINFO_OFFSET(page, _mapcount);
198 VMCOREINFO_OFFSET(page, private);
199 VMCOREINFO_OFFSET(page, compound_head);
200 VMCOREINFO_OFFSET(pglist_data, node_zones);
201 VMCOREINFO_OFFSET(pglist_data, nr_zones);
202#ifdef CONFIG_FLATMEM
203 VMCOREINFO_OFFSET(pglist_data, node_mem_map);
204#endif
205 VMCOREINFO_OFFSET(pglist_data, node_start_pfn);
206 VMCOREINFO_OFFSET(pglist_data, node_spanned_pages);
207 VMCOREINFO_OFFSET(pglist_data, node_id);
208 VMCOREINFO_OFFSET(zone, free_area);
209 VMCOREINFO_OFFSET(zone, vm_stat);
210 VMCOREINFO_OFFSET(zone, spanned_pages);
211 VMCOREINFO_OFFSET(free_area, free_list);
212 VMCOREINFO_OFFSET(list_head, next);
213 VMCOREINFO_OFFSET(list_head, prev);
214 VMCOREINFO_LENGTH(zone.free_area, NR_PAGE_ORDERS);
215 log_buf_vmcoreinfo_setup();
216 VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES);
217 VMCOREINFO_NUMBER(NR_FREE_PAGES);
218 VMCOREINFO_NUMBER(PG_lru);
219 VMCOREINFO_NUMBER(PG_private);
220 VMCOREINFO_NUMBER(PG_swapcache);
221 VMCOREINFO_NUMBER(PG_swapbacked);
222#define PAGE_SLAB_MAPCOUNT_VALUE (PGTY_slab << 24)
223 VMCOREINFO_NUMBER(PAGE_SLAB_MAPCOUNT_VALUE);
224#ifdef CONFIG_MEMORY_FAILURE
225 VMCOREINFO_NUMBER(PG_hwpoison);
226#endif
227 VMCOREINFO_NUMBER(PG_head_mask);
228#define PAGE_BUDDY_MAPCOUNT_VALUE (PGTY_buddy << 24)
229 VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE);
230#define PAGE_HUGETLB_MAPCOUNT_VALUE (PGTY_hugetlb << 24)
231 VMCOREINFO_NUMBER(PAGE_HUGETLB_MAPCOUNT_VALUE);
232#define PAGE_OFFLINE_MAPCOUNT_VALUE (PGTY_offline << 24)
233 VMCOREINFO_NUMBER(PAGE_OFFLINE_MAPCOUNT_VALUE);
234#ifdef CONFIG_UNACCEPTED_MEMORY
235#define PAGE_UNACCEPTED_MAPCOUNT_VALUE (PGTY_unaccepted << 24)
236 VMCOREINFO_NUMBER(PAGE_UNACCEPTED_MAPCOUNT_VALUE);
237#endif
238
239#ifdef CONFIG_KALLSYMS
240 VMCOREINFO_SYMBOL(kallsyms_names);
241 VMCOREINFO_SYMBOL(kallsyms_num_syms);
242 VMCOREINFO_SYMBOL(kallsyms_token_table);
243 VMCOREINFO_SYMBOL(kallsyms_token_index);
244 VMCOREINFO_SYMBOL(kallsyms_offsets);
245 VMCOREINFO_SYMBOL(kallsyms_relative_base);
246#endif /* CONFIG_KALLSYMS */
247
248 arch_crash_save_vmcoreinfo();
249 update_vmcoreinfo_note();
250
251 return 0;
252}
253
254subsys_initcall(crash_save_vmcoreinfo_init);
255

source code of linux/kernel/vmcore_info.c