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 "kallsyms_internal.h"
22 #include "kexec_internal.h"
23
24 /* vmcoreinfo stuff */
25 unsigned char *vmcoreinfo_data;
26 size_t vmcoreinfo_size;
27 u32 *vmcoreinfo_note;
28
29 /* trusted vmcoreinfo, e.g. we can make a copy in the crash memory */
30 static unsigned char *vmcoreinfo_data_safecopy;
31
32 struct hwerr_info {
33 atomic_t count;
34 time64_t timestamp;
35 };
36
37 /*
38 * The hwerr_data[] array is declared with global scope so that it remains
39 * accessible to vmcoreinfo even when Link Time Optimization (LTO) is enabled.
40 */
41 struct hwerr_info hwerr_data[HWERR_RECOV_MAX];
42
append_elf_note(Elf_Word * buf,char * name,unsigned int type,void * data,size_t data_len)43 Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type,
44 void *data, size_t data_len)
45 {
46 struct elf_note *note = (struct elf_note *)buf;
47
48 note->n_namesz = strlen(name) + 1;
49 note->n_descsz = data_len;
50 note->n_type = type;
51 buf += DIV_ROUND_UP(sizeof(*note), sizeof(Elf_Word));
52 memcpy(buf, name, note->n_namesz);
53 buf += DIV_ROUND_UP(note->n_namesz, sizeof(Elf_Word));
54 memcpy(buf, data, data_len);
55 buf += DIV_ROUND_UP(data_len, sizeof(Elf_Word));
56
57 return buf;
58 }
59
final_note(Elf_Word * buf)60 void final_note(Elf_Word *buf)
61 {
62 memset(buf, 0, sizeof(struct elf_note));
63 }
64
update_vmcoreinfo_note(void)65 static void update_vmcoreinfo_note(void)
66 {
67 u32 *buf = vmcoreinfo_note;
68
69 if (!vmcoreinfo_size)
70 return;
71 buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data,
72 vmcoreinfo_size);
73 final_note(buf);
74 }
75
crash_update_vmcoreinfo_safecopy(void * ptr)76 void crash_update_vmcoreinfo_safecopy(void *ptr)
77 {
78 if (ptr)
79 memcpy(ptr, vmcoreinfo_data, vmcoreinfo_size);
80
81 vmcoreinfo_data_safecopy = ptr;
82 }
83
crash_save_vmcoreinfo(void)84 void crash_save_vmcoreinfo(void)
85 {
86 if (!vmcoreinfo_note)
87 return;
88
89 /* Use the safe copy to generate vmcoreinfo note if have */
90 if (vmcoreinfo_data_safecopy)
91 vmcoreinfo_data = vmcoreinfo_data_safecopy;
92
93 vmcoreinfo_append_str("CRASHTIME=%lld\n", ktime_get_real_seconds());
94 update_vmcoreinfo_note();
95 }
96
vmcoreinfo_append_str(const char * fmt,...)97 void vmcoreinfo_append_str(const char *fmt, ...)
98 {
99 va_list args;
100 char buf[0x50];
101 size_t r;
102
103 va_start(args, fmt);
104 r = vscnprintf(buf, sizeof(buf), fmt, args);
105 va_end(args);
106
107 r = min(r, (size_t)VMCOREINFO_BYTES - vmcoreinfo_size);
108
109 memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r);
110
111 vmcoreinfo_size += r;
112
113 WARN_ONCE(vmcoreinfo_size == VMCOREINFO_BYTES,
114 "vmcoreinfo data exceeds allocated size, truncating");
115 }
116
117 /*
118 * provide an empty default implementation here -- architecture
119 * code may override this
120 */
arch_crash_save_vmcoreinfo(void)121 void __weak arch_crash_save_vmcoreinfo(void)
122 {}
123
paddr_vmcoreinfo_note(void)124 phys_addr_t __weak paddr_vmcoreinfo_note(void)
125 {
126 return __pa(vmcoreinfo_note);
127 }
128 EXPORT_SYMBOL(paddr_vmcoreinfo_note);
129
hwerr_log_error_type(enum hwerr_error_type src)130 void hwerr_log_error_type(enum hwerr_error_type src)
131 {
132 if (src < 0 || src >= HWERR_RECOV_MAX)
133 return;
134
135 atomic_inc(&hwerr_data[src].count);
136 WRITE_ONCE(hwerr_data[src].timestamp, ktime_get_real_seconds());
137 }
138 EXPORT_SYMBOL_GPL(hwerr_log_error_type);
139
crash_save_vmcoreinfo_init(void)140 static int __init crash_save_vmcoreinfo_init(void)
141 {
142 int order;
143 order = get_order(VMCOREINFO_BYTES);
144 vmcoreinfo_data = (unsigned char *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
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_pages((unsigned long)vmcoreinfo_data, order);
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("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_info);
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 #endif /* CONFIG_KALLSYMS */
246
247 arch_crash_save_vmcoreinfo();
248 update_vmcoreinfo_note();
249
250 return 0;
251 }
252
253 subsys_initcall(crash_save_vmcoreinfo_init);
254