kernel/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 */
  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 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
  51 void final_note(Elf_Word *buf)
  52 {
  53         memset(buf, 0, sizeof(struct elf_note));
  54 }
  55
  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
  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
  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
  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  */
 112 void __weak arch_crash_save_vmcoreinfo(void)
 113 {}
 114
 115 phys_addr_t __weak paddr_vmcoreinfo_note(void)
 116 {
 117         return __pa(vmcoreinfo_note);
 118 }
 119 EXPORT_SYMBOL(paddr_vmcoreinfo_note);
 120
 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);