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
append_elf_note(Elf_Word * buf,char * name,unsigned int type,void * data,size_t data_len)34 Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type,
35 void *data, size_t data_len)
36 {
37 struct elf_note *note = (struct elf_note *)buf;
38
39 note->n_namesz = strlen(name) + 1;
40 note->n_descsz = data_len;
41 note->n_type = type;
42 buf += DIV_ROUND_UP(sizeof(*note), sizeof(Elf_Word));
43 memcpy(buf, name, note->n_namesz);
44 buf += DIV_ROUND_UP(note->n_namesz, sizeof(Elf_Word));
45 memcpy(buf, data, data_len);
46 buf += DIV_ROUND_UP(data_len, sizeof(Elf_Word));
47
48 return buf;
49 }
50
final_note(Elf_Word * buf)51 void final_note(Elf_Word *buf)
52 {
53 memset(buf, 0, sizeof(struct elf_note));
54 }
55
update_vmcoreinfo_note(void)56 static void update_vmcoreinfo_note(void)
57 {
58 u32 *buf = vmcoreinfo_note;
59
60 if (!vmcoreinfo_size)
61 return;
62 buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data,
63 vmcoreinfo_size);
64 final_note(buf);
65 }
66
crash_update_vmcoreinfo_safecopy(void * ptr)67 void crash_update_vmcoreinfo_safecopy(void *ptr)
68 {
69 if (ptr)
70 memcpy(ptr, vmcoreinfo_data, vmcoreinfo_size);
71
72 vmcoreinfo_data_safecopy = ptr;
73 }
74
crash_save_vmcoreinfo(void)75 void crash_save_vmcoreinfo(void)
76 {
77 if (!vmcoreinfo_note)
78 return;
79
80 /* Use the safe copy to generate vmcoreinfo note if have */
81 if (vmcoreinfo_data_safecopy)
82 vmcoreinfo_data = vmcoreinfo_data_safecopy;
83
84 vmcoreinfo_append_str("CRASHTIME=%lld\n", ktime_get_real_seconds());
85 update_vmcoreinfo_note();
86 }
87
vmcoreinfo_append_str(const char * fmt,...)88 void vmcoreinfo_append_str(const char *fmt, ...)
89 {
90 va_list args;
91 char buf[0x50];
92 size_t r;
93
94 va_start(args, fmt);
95 r = vscnprintf(buf, sizeof(buf), fmt, args);
96 va_end(args);
97
98 r = min(r, (size_t)VMCOREINFO_BYTES - vmcoreinfo_size);
99
100 memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r);
101
102 vmcoreinfo_size += r;
103
104 WARN_ONCE(vmcoreinfo_size == VMCOREINFO_BYTES,
105 "vmcoreinfo data exceeds allocated size, truncating");
106 }
107
108 /*
109 * provide an empty default implementation here -- architecture
110 * code may override this
111 */
arch_crash_save_vmcoreinfo(void)112 void __weak arch_crash_save_vmcoreinfo(void)
113 {}
114
paddr_vmcoreinfo_note(void)115 phys_addr_t __weak paddr_vmcoreinfo_note(void)
116 {
117 return __pa(vmcoreinfo_note);
118 }
119 EXPORT_SYMBOL(paddr_vmcoreinfo_note);
120
crash_save_vmcoreinfo_init(void)121 static int __init crash_save_vmcoreinfo_init(void)
122 {
123 vmcoreinfo_data = (unsigned char *)get_zeroed_page(GFP_KERNEL);
124 if (!vmcoreinfo_data) {
125 pr_warn("Memory allocation for vmcoreinfo_data failed\n");
126 return -ENOMEM;
127 }
128
129 vmcoreinfo_note = alloc_pages_exact(VMCOREINFO_NOTE_SIZE,
130 GFP_KERNEL | __GFP_ZERO);
131 if (!vmcoreinfo_note) {
132 free_page((unsigned long)vmcoreinfo_data);
133 vmcoreinfo_data = NULL;
134 pr_warn("Memory allocation for vmcoreinfo_note failed\n");
135 return -ENOMEM;
136 }
137
138 VMCOREINFO_OSRELEASE(init_uts_ns.name.release);
139 VMCOREINFO_BUILD_ID();
140 VMCOREINFO_PAGESIZE(PAGE_SIZE);
141
142 VMCOREINFO_SYMBOL(init_uts_ns);
143 VMCOREINFO_OFFSET(uts_namespace, name);
144 VMCOREINFO_SYMBOL(node_online_map);
145 #ifdef CONFIG_MMU
146 VMCOREINFO_SYMBOL_ARRAY(swapper_pg_dir);
147 #endif
148 VMCOREINFO_SYMBOL(_stext);
149 vmcoreinfo_append_str("NUMBER(VMALLOC_START)=0x%lx\n", (unsigned long) VMALLOC_START);
150
151 #ifndef CONFIG_NUMA
152 VMCOREINFO_SYMBOL(mem_map);
153 VMCOREINFO_SYMBOL(contig_page_data);
154 #endif
155 #ifdef CONFIG_SPARSEMEM_VMEMMAP
156 VMCOREINFO_SYMBOL_ARRAY(vmemmap);
157 #endif
158 #ifdef CONFIG_SPARSEMEM
159 VMCOREINFO_SYMBOL_ARRAY(mem_section);
160 VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
161 VMCOREINFO_STRUCT_SIZE(mem_section);
162 VMCOREINFO_OFFSET(mem_section, section_mem_map);
163 VMCOREINFO_NUMBER(SECTION_SIZE_BITS);
164 VMCOREINFO_NUMBER(MAX_PHYSMEM_BITS);
165 #endif
166 VMCOREINFO_STRUCT_SIZE(page);
167 VMCOREINFO_STRUCT_SIZE(pglist_data);
168 VMCOREINFO_STRUCT_SIZE(zone);
169 VMCOREINFO_STRUCT_SIZE(free_area);
170 VMCOREINFO_STRUCT_SIZE(list_head);
171 VMCOREINFO_SIZE(nodemask_t);
172 VMCOREINFO_OFFSET(page, flags);
173 VMCOREINFO_OFFSET(page, _refcount);
174 VMCOREINFO_OFFSET(page, mapping);
175 VMCOREINFO_OFFSET(page, lru);
176 VMCOREINFO_OFFSET(page, _mapcount);
177 VMCOREINFO_OFFSET(page, private);
178 VMCOREINFO_OFFSET(page, compound_head);
179 VMCOREINFO_OFFSET(pglist_data, node_zones);
180 VMCOREINFO_OFFSET(pglist_data, nr_zones);
181 #ifdef CONFIG_FLATMEM
182 VMCOREINFO_OFFSET(pglist_data, node_mem_map);
183 #endif
184 VMCOREINFO_OFFSET(pglist_data, node_start_pfn);
185 VMCOREINFO_OFFSET(pglist_data, node_spanned_pages);
186 VMCOREINFO_OFFSET(pglist_data, node_id);
187 VMCOREINFO_OFFSET(zone, free_area);
188 VMCOREINFO_OFFSET(zone, vm_stat);
189 VMCOREINFO_OFFSET(zone, spanned_pages);
190 VMCOREINFO_OFFSET(free_area, free_list);
191 VMCOREINFO_OFFSET(list_head, next);
192 VMCOREINFO_OFFSET(list_head, prev);
193 VMCOREINFO_LENGTH(zone.free_area, NR_PAGE_ORDERS);
194 log_buf_vmcoreinfo_setup();
195 VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES);
196 VMCOREINFO_NUMBER(NR_FREE_PAGES);
197 VMCOREINFO_NUMBER(PG_lru);
198 VMCOREINFO_NUMBER(PG_private);
199 VMCOREINFO_NUMBER(PG_swapcache);
200 VMCOREINFO_NUMBER(PG_swapbacked);
201 #define PAGE_SLAB_MAPCOUNT_VALUE (PGTY_slab << 24)
202 VMCOREINFO_NUMBER(PAGE_SLAB_MAPCOUNT_VALUE);
203 #ifdef CONFIG_MEMORY_FAILURE
204 VMCOREINFO_NUMBER(PG_hwpoison);
205 #endif
206 VMCOREINFO_NUMBER(PG_head_mask);
207 #define PAGE_BUDDY_MAPCOUNT_VALUE (PGTY_buddy << 24)
208 VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE);
209 #define PAGE_HUGETLB_MAPCOUNT_VALUE (PGTY_hugetlb << 24)
210 VMCOREINFO_NUMBER(PAGE_HUGETLB_MAPCOUNT_VALUE);
211 #define PAGE_OFFLINE_MAPCOUNT_VALUE (PGTY_offline << 24)
212 VMCOREINFO_NUMBER(PAGE_OFFLINE_MAPCOUNT_VALUE);
213
214 #ifdef CONFIG_KALLSYMS
215 VMCOREINFO_SYMBOL(kallsyms_names);
216 VMCOREINFO_SYMBOL(kallsyms_num_syms);
217 VMCOREINFO_SYMBOL(kallsyms_token_table);
218 VMCOREINFO_SYMBOL(kallsyms_token_index);
219 VMCOREINFO_SYMBOL(kallsyms_offsets);
220 VMCOREINFO_SYMBOL(kallsyms_relative_base);
221 #endif /* CONFIG_KALLSYMS */
222
223 arch_crash_save_vmcoreinfo();
224 update_vmcoreinfo_note();
225
226 return 0;
227 }
228
229 subsys_initcall(crash_save_vmcoreinfo_init);
230