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
 34Elf_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
 51void final_note(Elf_Word *buf)
 52{
 53	memset(buf, 0, sizeof(struct elf_note));
 54}
 55
 56static 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
 67void 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
 75void 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
 88void 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 */
112void __weak arch_crash_save_vmcoreinfo(void)
113{}
114
115phys_addr_t __weak paddr_vmcoreinfo_note(void)
116{
117	return __pa(vmcoreinfo_note);
118}
119EXPORT_SYMBOL(paddr_vmcoreinfo_note);
120
121static 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
229subsys_initcall(crash_save_vmcoreinfo_init);