vmcore_info.c

  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, 0, vmcoreinfo_data,
 74			      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("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, 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(&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("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);