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 */
27 unsigned char *vmcoreinfo_data;
28 size_t vmcoreinfo_size;
29 u32 *vmcoreinfo_note;
30
31 /* trusted vmcoreinfo, e.g. we can make a copy in the crash memory */
32 static unsigned char *vmcoreinfo_data_safecopy;
33
34 struct 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 */
43 struct hwerr_info hwerr_data[HWERR_RECOV_MAX];
44
append_elf_note(Elf_Word * buf,char * name,unsigned int type,void * data,size_t data_len)45 Elf_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
final_note(Elf_Word * buf)62 void final_note(Elf_Word *buf)
63 {
64 memset(buf, 0, sizeof(struct elf_note));
65 }
66
update_vmcoreinfo_note(void)67 static 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, 0, vmcoreinfo_data,
74 vmcoreinfo_size);
75 final_note(buf);
76 }
77
crash_update_vmcoreinfo_safecopy(void * ptr)78 void 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
crash_save_vmcoreinfo(void)86 void 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("CRASHTIME=%lld\n", ktime_get_real_seconds());
96 update_vmcoreinfo_note();
97 }
98
vmcoreinfo_append_str(const char * fmt,...)99 void 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, 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 */
arch_crash_save_vmcoreinfo(void)123 void __weak arch_crash_save_vmcoreinfo(void)
124 {}
125
paddr_vmcoreinfo_note(void)126 phys_addr_t __weak paddr_vmcoreinfo_note(void)
127 {
128 return __pa(vmcoreinfo_note);
129 }
130 EXPORT_SYMBOL(paddr_vmcoreinfo_note);
131
hwerr_log_error_type(enum hwerr_error_type src)132 void hwerr_log_error_type(enum hwerr_error_type src)
133 {
134 if (src < 0 || src >= HWERR_RECOV_MAX)
135 return;
136
137 atomic_inc(&hwerr_data[src].count);
138 WRITE_ONCE(hwerr_data[src].timestamp, ktime_get_real_seconds());
139 }
140 EXPORT_SYMBOL_GPL(hwerr_log_error_type);
141
crash_save_vmcoreinfo_init(void)142 static int __init crash_save_vmcoreinfo_init(void)
143 {
144 int order;
145 order = get_order(VMCOREINFO_BYTES);
146 vmcoreinfo_data = (unsigned char *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
147 if (!vmcoreinfo_data) {
148 pr_warn("Memory allocation for vmcoreinfo_data failed\n");
149 return -ENOMEM;
150 }
151
152 vmcoreinfo_note = alloc_pages_exact(VMCOREINFO_NOTE_SIZE,
153 GFP_KERNEL | __GFP_ZERO);
154 if (!vmcoreinfo_note) {
155 free_pages((unsigned long)vmcoreinfo_data, order);
156 vmcoreinfo_data = NULL;
157 pr_warn("Memory allocation for vmcoreinfo_note failed\n");
158 return -ENOMEM;
159 }
160
161 VMCOREINFO_OSRELEASE(init_uts_ns.name.release);
162 VMCOREINFO_BUILD_ID();
163 VMCOREINFO_PAGESIZE(PAGE_SIZE);
164
165 VMCOREINFO_SYMBOL(init_uts_ns);
166 VMCOREINFO_OFFSET(uts_namespace, name);
167 VMCOREINFO_SYMBOL(node_online_map);
168 #ifdef CONFIG_MMU
169 VMCOREINFO_SYMBOL_ARRAY(swapper_pg_dir);
170 #endif
171 VMCOREINFO_SYMBOL(_stext);
172 vmcoreinfo_append_str("NUMBER(VMALLOC_START)=0x%lx\n", (unsigned long) VMALLOC_START);
173
174 #ifndef CONFIG_NUMA
175 VMCOREINFO_SYMBOL(mem_map);
176 VMCOREINFO_SYMBOL(contig_page_data);
177 #endif
178 #ifdef CONFIG_SPARSEMEM_VMEMMAP
179 VMCOREINFO_SYMBOL_ARRAY(vmemmap);
180 #endif
181 #ifdef CONFIG_SPARSEMEM
182 VMCOREINFO_SYMBOL_ARRAY(mem_section);
183 VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
184 VMCOREINFO_STRUCT_SIZE(mem_section);
185 VMCOREINFO_OFFSET(mem_section, section_mem_map);
186 VMCOREINFO_NUMBER(SECTION_SIZE_BITS);
187 VMCOREINFO_NUMBER(MAX_PHYSMEM_BITS);
188 #endif
189 VMCOREINFO_STRUCT_SIZE(page);
190 VMCOREINFO_STRUCT_SIZE(pglist_data);
191 VMCOREINFO_STRUCT_SIZE(zone);
192 VMCOREINFO_STRUCT_SIZE(free_area);
193 VMCOREINFO_STRUCT_SIZE(list_head);
194 VMCOREINFO_SIZE(nodemask_t);
195 VMCOREINFO_OFFSET(page, flags);
196 VMCOREINFO_OFFSET(page, _refcount);
197 VMCOREINFO_OFFSET(page, mapping);
198 VMCOREINFO_OFFSET(page, lru);
199 VMCOREINFO_OFFSET(page, _mapcount);
200 VMCOREINFO_OFFSET(page, private);
201 VMCOREINFO_OFFSET(page, compound_head);
202 VMCOREINFO_OFFSET(pglist_data, node_zones);
203 VMCOREINFO_OFFSET(pglist_data, nr_zones);
204 #ifdef CONFIG_FLATMEM
205 VMCOREINFO_OFFSET(pglist_data, node_mem_map);
206 #endif
207 VMCOREINFO_OFFSET(pglist_data, node_start_pfn);
208 VMCOREINFO_OFFSET(pglist_data, node_spanned_pages);
209 VMCOREINFO_OFFSET(pglist_data, node_id);
210 VMCOREINFO_OFFSET(zone, free_area);
211 VMCOREINFO_OFFSET(zone, vm_stat);
212 VMCOREINFO_OFFSET(zone, spanned_pages);
213 VMCOREINFO_OFFSET(free_area, free_list);
214 VMCOREINFO_OFFSET(list_head, next);
215 VMCOREINFO_OFFSET(list_head, prev);
216 VMCOREINFO_LENGTH(zone.free_area, NR_PAGE_ORDERS);
217 log_buf_vmcoreinfo_setup();
218 VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES);
219 VMCOREINFO_NUMBER(NR_FREE_PAGES);
220 VMCOREINFO_NUMBER(PG_lru);
221 VMCOREINFO_NUMBER(PG_private);
222 VMCOREINFO_NUMBER(PG_swapcache);
223 VMCOREINFO_NUMBER(PG_swapbacked);
224 #define PAGE_SLAB_MAPCOUNT_VALUE (PGTY_slab << 24)
225 VMCOREINFO_NUMBER(PAGE_SLAB_MAPCOUNT_VALUE);
226 #ifdef CONFIG_MEMORY_FAILURE
227 VMCOREINFO_NUMBER(PG_hwpoison);
228 #endif
229 VMCOREINFO_NUMBER(PG_head_mask);
230 #define PAGE_BUDDY_MAPCOUNT_VALUE (PGTY_buddy << 24)
231 VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE);
232 #define PAGE_HUGETLB_MAPCOUNT_VALUE (PGTY_hugetlb << 24)
233 VMCOREINFO_NUMBER(PAGE_HUGETLB_MAPCOUNT_VALUE);
234 #define PAGE_OFFLINE_MAPCOUNT_VALUE (PGTY_offline << 24)
235 VMCOREINFO_NUMBER(PAGE_OFFLINE_MAPCOUNT_VALUE);
236 #ifdef CONFIG_UNACCEPTED_MEMORY
237 #define PAGE_UNACCEPTED_MAPCOUNT_VALUE (PGTY_unaccepted << 24)
238 VMCOREINFO_NUMBER(PAGE_UNACCEPTED_MAPCOUNT_VALUE);
239 #endif
240
241 #ifdef CONFIG_KALLSYMS
242 VMCOREINFO_SYMBOL(kallsyms_names);
243 VMCOREINFO_SYMBOL(kallsyms_num_syms);
244 VMCOREINFO_SYMBOL(kallsyms_token_table);
245 VMCOREINFO_SYMBOL(kallsyms_token_index);
246 VMCOREINFO_SYMBOL(kallsyms_offsets);
247 #endif /* CONFIG_KALLSYMS */
248
249 arch_crash_save_vmcoreinfo();
250 update_vmcoreinfo_note();
251
252 return 0;
253 }
254
255 subsys_initcall(crash_save_vmcoreinfo_init);
256