swh:1:snp:77163734605b0ec556b01d897b7bb4a7e30d46b6
Tip revision: 0adb32858b0bddf4ada5f364a84ed60b196dbcda authored by Linus Torvalds on 01 April 2018, 21:20:27 UTC
Linux 4.16
Linux 4.16
Tip revision: 0adb328
crash_core.c
/*
* crash.c - kernel crash support code.
* Copyright (C) 2002-2004 Eric Biederman <ebiederm@xmission.com>
*
* This source code is licensed under the GNU General Public License,
* Version 2. See the file COPYING for more details.
*/
#include <linux/crash_core.h>
#include <linux/utsname.h>
#include <linux/vmalloc.h>
#include <asm/page.h>
#include <asm/sections.h>
/* vmcoreinfo stuff */
static unsigned char *vmcoreinfo_data;
static size_t vmcoreinfo_size;
u32 *vmcoreinfo_note;
/* trusted vmcoreinfo, e.g. we can make a copy in the crash memory */
static unsigned char *vmcoreinfo_data_safecopy;
/*
* parsing the "crashkernel" commandline
*
* this code is intended to be called from architecture specific code
*/
/*
* This function parses command lines in the format
*
* crashkernel=ramsize-range:size[,...][@offset]
*
* The function returns 0 on success and -EINVAL on failure.
*/
static int __init parse_crashkernel_mem(char *cmdline,
unsigned long long system_ram,
unsigned long long *crash_size,
unsigned long long *crash_base)
{
char *cur = cmdline, *tmp;
/* for each entry of the comma-separated list */
do {
unsigned long long start, end = ULLONG_MAX, size;
/* get the start of the range */
start = memparse(cur, &tmp);
if (cur == tmp) {
pr_warn("crashkernel: Memory value expected\n");
return -EINVAL;
}
cur = tmp;
if (*cur != '-') {
pr_warn("crashkernel: '-' expected\n");
return -EINVAL;
}
cur++;
/* if no ':' is here, than we read the end */
if (*cur != ':') {
end = memparse(cur, &tmp);
if (cur == tmp) {
pr_warn("crashkernel: Memory value expected\n");
return -EINVAL;
}
cur = tmp;
if (end <= start) {
pr_warn("crashkernel: end <= start\n");
return -EINVAL;
}
}
if (*cur != ':') {
pr_warn("crashkernel: ':' expected\n");
return -EINVAL;
}
cur++;
size = memparse(cur, &tmp);
if (cur == tmp) {
pr_warn("Memory value expected\n");
return -EINVAL;
}
cur = tmp;
if (size >= system_ram) {
pr_warn("crashkernel: invalid size\n");
return -EINVAL;
}
/* match ? */
if (system_ram >= start && system_ram < end) {
*crash_size = size;
break;
}
} while (*cur++ == ',');
if (*crash_size > 0) {
while (*cur && *cur != ' ' && *cur != '@')
cur++;
if (*cur == '@') {
cur++;
*crash_base = memparse(cur, &tmp);
if (cur == tmp) {
pr_warn("Memory value expected after '@'\n");
return -EINVAL;
}
}
} else
pr_info("crashkernel size resulted in zero bytes\n");
return 0;
}
/*
* That function parses "simple" (old) crashkernel command lines like
*
* crashkernel=size[@offset]
*
* It returns 0 on success and -EINVAL on failure.
*/
static int __init parse_crashkernel_simple(char *cmdline,
unsigned long long *crash_size,
unsigned long long *crash_base)
{
char *cur = cmdline;
*crash_size = memparse(cmdline, &cur);
if (cmdline == cur) {
pr_warn("crashkernel: memory value expected\n");
return -EINVAL;
}
if (*cur == '@')
*crash_base = memparse(cur+1, &cur);
else if (*cur != ' ' && *cur != '\0') {
pr_warn("crashkernel: unrecognized char: %c\n", *cur);
return -EINVAL;
}
return 0;
}
#define SUFFIX_HIGH 0
#define SUFFIX_LOW 1
#define SUFFIX_NULL 2
static __initdata char *suffix_tbl[] = {
[SUFFIX_HIGH] = ",high",
[SUFFIX_LOW] = ",low",
[SUFFIX_NULL] = NULL,
};
/*
* That function parses "suffix" crashkernel command lines like
*
* crashkernel=size,[high|low]
*
* It returns 0 on success and -EINVAL on failure.
*/
static int __init parse_crashkernel_suffix(char *cmdline,
unsigned long long *crash_size,
const char *suffix)
{
char *cur = cmdline;
*crash_size = memparse(cmdline, &cur);
if (cmdline == cur) {
pr_warn("crashkernel: memory value expected\n");
return -EINVAL;
}
/* check with suffix */
if (strncmp(cur, suffix, strlen(suffix))) {
pr_warn("crashkernel: unrecognized char: %c\n", *cur);
return -EINVAL;
}
cur += strlen(suffix);
if (*cur != ' ' && *cur != '\0') {
pr_warn("crashkernel: unrecognized char: %c\n", *cur);
return -EINVAL;
}
return 0;
}
static __init char *get_last_crashkernel(char *cmdline,
const char *name,
const char *suffix)
{
char *p = cmdline, *ck_cmdline = NULL;
/* find crashkernel and use the last one if there are more */
p = strstr(p, name);
while (p) {
char *end_p = strchr(p, ' ');
char *q;
if (!end_p)
end_p = p + strlen(p);
if (!suffix) {
int i;
/* skip the one with any known suffix */
for (i = 0; suffix_tbl[i]; i++) {
q = end_p - strlen(suffix_tbl[i]);
if (!strncmp(q, suffix_tbl[i],
strlen(suffix_tbl[i])))
goto next;
}
ck_cmdline = p;
} else {
q = end_p - strlen(suffix);
if (!strncmp(q, suffix, strlen(suffix)))
ck_cmdline = p;
}
next:
p = strstr(p+1, name);
}
if (!ck_cmdline)
return NULL;
return ck_cmdline;
}
static int __init __parse_crashkernel(char *cmdline,
unsigned long long system_ram,
unsigned long long *crash_size,
unsigned long long *crash_base,
const char *name,
const char *suffix)
{
char *first_colon, *first_space;
char *ck_cmdline;
BUG_ON(!crash_size || !crash_base);
*crash_size = 0;
*crash_base = 0;
ck_cmdline = get_last_crashkernel(cmdline, name, suffix);
if (!ck_cmdline)
return -EINVAL;
ck_cmdline += strlen(name);
if (suffix)
return parse_crashkernel_suffix(ck_cmdline, crash_size,
suffix);
/*
* if the commandline contains a ':', then that's the extended
* syntax -- if not, it must be the classic syntax
*/
first_colon = strchr(ck_cmdline, ':');
first_space = strchr(ck_cmdline, ' ');
if (first_colon && (!first_space || first_colon < first_space))
return parse_crashkernel_mem(ck_cmdline, system_ram,
crash_size, crash_base);
return parse_crashkernel_simple(ck_cmdline, crash_size, crash_base);
}
/*
* That function is the entry point for command line parsing and should be
* called from the arch-specific code.
*/
int __init parse_crashkernel(char *cmdline,
unsigned long long system_ram,
unsigned long long *crash_size,
unsigned long long *crash_base)
{
return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
"crashkernel=", NULL);
}
int __init parse_crashkernel_high(char *cmdline,
unsigned long long system_ram,
unsigned long long *crash_size,
unsigned long long *crash_base)
{
return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
"crashkernel=", suffix_tbl[SUFFIX_HIGH]);
}
int __init parse_crashkernel_low(char *cmdline,
unsigned long long system_ram,
unsigned long long *crash_size,
unsigned long long *crash_base)
{
return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
"crashkernel=", suffix_tbl[SUFFIX_LOW]);
}
Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type,
void *data, size_t data_len)
{
struct elf_note *note = (struct elf_note *)buf;
note->n_namesz = strlen(name) + 1;
note->n_descsz = data_len;
note->n_type = type;
buf += DIV_ROUND_UP(sizeof(*note), sizeof(Elf_Word));
memcpy(buf, name, note->n_namesz);
buf += DIV_ROUND_UP(note->n_namesz, sizeof(Elf_Word));
memcpy(buf, data, data_len);
buf += DIV_ROUND_UP(data_len, sizeof(Elf_Word));
return buf;
}
void final_note(Elf_Word *buf)
{
memset(buf, 0, sizeof(struct elf_note));
}
static void update_vmcoreinfo_note(void)
{
u32 *buf = vmcoreinfo_note;
if (!vmcoreinfo_size)
return;
buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data,
vmcoreinfo_size);
final_note(buf);
}
void crash_update_vmcoreinfo_safecopy(void *ptr)
{
if (ptr)
memcpy(ptr, vmcoreinfo_data, vmcoreinfo_size);
vmcoreinfo_data_safecopy = ptr;
}
void crash_save_vmcoreinfo(void)
{
if (!vmcoreinfo_note)
return;
/* Use the safe copy to generate vmcoreinfo note if have */
if (vmcoreinfo_data_safecopy)
vmcoreinfo_data = vmcoreinfo_data_safecopy;
vmcoreinfo_append_str("CRASHTIME=%ld\n", get_seconds());
update_vmcoreinfo_note();
}
void vmcoreinfo_append_str(const char *fmt, ...)
{
va_list args;
char buf[0x50];
size_t r;
va_start(args, fmt);
r = vscnprintf(buf, sizeof(buf), fmt, args);
va_end(args);
r = min(r, (size_t)VMCOREINFO_BYTES - vmcoreinfo_size);
memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r);
vmcoreinfo_size += r;
}
/*
* provide an empty default implementation here -- architecture
* code may override this
*/
void __weak arch_crash_save_vmcoreinfo(void)
{}
phys_addr_t __weak paddr_vmcoreinfo_note(void)
{
return __pa(vmcoreinfo_note);
}
static int __init crash_save_vmcoreinfo_init(void)
{
vmcoreinfo_data = (unsigned char *)get_zeroed_page(GFP_KERNEL);
if (!vmcoreinfo_data) {
pr_warn("Memory allocation for vmcoreinfo_data failed\n");
return -ENOMEM;
}
vmcoreinfo_note = alloc_pages_exact(VMCOREINFO_NOTE_SIZE,
GFP_KERNEL | __GFP_ZERO);
if (!vmcoreinfo_note) {
free_page((unsigned long)vmcoreinfo_data);
vmcoreinfo_data = NULL;
pr_warn("Memory allocation for vmcoreinfo_note failed\n");
return -ENOMEM;
}
VMCOREINFO_OSRELEASE(init_uts_ns.name.release);
VMCOREINFO_PAGESIZE(PAGE_SIZE);
VMCOREINFO_SYMBOL(init_uts_ns);
VMCOREINFO_SYMBOL(node_online_map);
#ifdef CONFIG_MMU
VMCOREINFO_SYMBOL(swapper_pg_dir);
#endif
VMCOREINFO_SYMBOL(_stext);
VMCOREINFO_SYMBOL(vmap_area_list);
#ifndef CONFIG_NEED_MULTIPLE_NODES
VMCOREINFO_SYMBOL(mem_map);
VMCOREINFO_SYMBOL(contig_page_data);
#endif
#ifdef CONFIG_SPARSEMEM
VMCOREINFO_SYMBOL_ARRAY(mem_section);
VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
VMCOREINFO_STRUCT_SIZE(mem_section);
VMCOREINFO_OFFSET(mem_section, section_mem_map);
#endif
VMCOREINFO_STRUCT_SIZE(page);
VMCOREINFO_STRUCT_SIZE(pglist_data);
VMCOREINFO_STRUCT_SIZE(zone);
VMCOREINFO_STRUCT_SIZE(free_area);
VMCOREINFO_STRUCT_SIZE(list_head);
VMCOREINFO_SIZE(nodemask_t);
VMCOREINFO_OFFSET(page, flags);
VMCOREINFO_OFFSET(page, _refcount);
VMCOREINFO_OFFSET(page, mapping);
VMCOREINFO_OFFSET(page, lru);
VMCOREINFO_OFFSET(page, _mapcount);
VMCOREINFO_OFFSET(page, private);
VMCOREINFO_OFFSET(page, compound_dtor);
VMCOREINFO_OFFSET(page, compound_order);
VMCOREINFO_OFFSET(page, compound_head);
VMCOREINFO_OFFSET(pglist_data, node_zones);
VMCOREINFO_OFFSET(pglist_data, nr_zones);
#ifdef CONFIG_FLAT_NODE_MEM_MAP
VMCOREINFO_OFFSET(pglist_data, node_mem_map);
#endif
VMCOREINFO_OFFSET(pglist_data, node_start_pfn);
VMCOREINFO_OFFSET(pglist_data, node_spanned_pages);
VMCOREINFO_OFFSET(pglist_data, node_id);
VMCOREINFO_OFFSET(zone, free_area);
VMCOREINFO_OFFSET(zone, vm_stat);
VMCOREINFO_OFFSET(zone, spanned_pages);
VMCOREINFO_OFFSET(free_area, free_list);
VMCOREINFO_OFFSET(list_head, next);
VMCOREINFO_OFFSET(list_head, prev);
VMCOREINFO_OFFSET(vmap_area, va_start);
VMCOREINFO_OFFSET(vmap_area, list);
VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER);
log_buf_vmcoreinfo_setup();
VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES);
VMCOREINFO_NUMBER(NR_FREE_PAGES);
VMCOREINFO_NUMBER(PG_lru);
VMCOREINFO_NUMBER(PG_private);
VMCOREINFO_NUMBER(PG_swapcache);
VMCOREINFO_NUMBER(PG_slab);
#ifdef CONFIG_MEMORY_FAILURE
VMCOREINFO_NUMBER(PG_hwpoison);
#endif
VMCOREINFO_NUMBER(PG_head_mask);
VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE);
#ifdef CONFIG_HUGETLB_PAGE
VMCOREINFO_NUMBER(HUGETLB_PAGE_DTOR);
#endif
arch_crash_save_vmcoreinfo();
update_vmcoreinfo_note();
return 0;
}
subsys_initcall(crash_save_vmcoreinfo_init);