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 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 60 void final_note(Elf_Word *buf) 61 { 62 memset(buf, 0, sizeof(struct elf_note)); 63 } 64 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 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 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 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 */ 121 void __weak arch_crash_save_vmcoreinfo(void) 122 {} 123 124 phys_addr_t __weak paddr_vmcoreinfo_note(void) 125 { 126 return __pa(vmcoreinfo_note); 127 } 128 EXPORT_SYMBOL(paddr_vmcoreinfo_note); 129 130 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); 139 140 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