// SPDX-License-Identifier: GPL-2.0-only
/*
* crash.c - kernel crash support code.
* Copyright (C) 2002-2004 Eric Biederman <[email protected]>
*/
#include <linux/buildid.h>
#include <linux/init.h>
#include <linux/utsname.h>
#include <linux/vmalloc.h>
#include <linux/sizes.h>
#include <linux/kexec.h>
#include <linux/memory.h>
#include <linux/cpuhotplug.h>
#include <linux/memblock.h>
#include <linux/kmemleak.h>
#include <asm/page.h>
#include <asm/sections.h>
#include <crypto/sha1.h>
#include "kallsyms_internal.h"
#include "kexec_internal.h"
/* Location of the reserved area for the crash kernel */
struct resource crashk_res = {
.name = "Crash kernel",
.start = 0,
.end = 0,
.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
.desc = IORES_DESC_CRASH_KERNEL
};
struct resource crashk_low_res = {
.name = "Crash kernel",
.start = 0,
.end = 0,
.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
.desc = IORES_DESC_CRASH_KERNEL
};
/*
* 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;
unsigned long long total_mem = system_ram;
/*
* Firmware sometimes reserves some memory regions for its own use,
* so the system memory size is less than the actual physical memory
* size. Work around this by rounding up the total size to 128M,
* which is enough for most test cases.
*/
total_mem = roundup(total_mem, SZ_128M);
/* 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("crashkernel: Memory value expected\n");
return -EINVAL;
}
cur = tmp;
if (size >= total_mem) {
pr_warn("crashkernel: invalid size\n");
return -EINVAL;
}
/* match ? */
if (total_mem >= start && total_mem < 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("crahskernel: 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);
}
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 *suffix)
{
char *first_colon, *first_space;
char *ck_cmdline;
char *name = "crashkernel=";
BUG_ON(!crash_size || !crash_base);
*crash_size = 0;
*crash_base = 0;
ck_cmdline = get_last_crashkernel(cmdline, name, suffix);
if (!ck_cmdline)
return -ENOENT;
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.
*
* If crashkernel=,high|low is supported on architecture, non-NULL values
* should be passed to parameters 'low_size' and 'high'.
*/
int __init parse_crashkernel(char *cmdline,
unsigned long long system_ram,
unsigned long long *crash_size,
unsigned long long *crash_base,
unsigned long long *low_size,
bool *high)
{
int ret;
/* crashkernel=X[@offset] */
ret = __parse_crashkernel(cmdline, system_ram, crash_size,
crash_base, NULL);
#ifdef CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
/*
* If non-NULL 'high' passed in and no normal crashkernel
* setting detected, try parsing crashkernel=,high|low.
*/
if (high && ret == -ENOENT) {
ret = __parse_crashkernel(cmdline, 0, crash_size,
crash_base, suffix_tbl[SUFFIX_HIGH]);
if (ret || !*crash_size)
return -EINVAL;
/*
* crashkernel=Y,low can be specified or not, but invalid value
* is not allowed.
*/
ret = __parse_crashkernel(cmdline, 0, low_size,
crash_base, suffix_tbl[SUFFIX_LOW]);
if (ret == -ENOENT) {
*low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE;
ret = 0;
} else if (ret) {
return ret;
}
*high = true;
}
#endif
if (!*crash_size)
ret = -EINVAL;
if (*crash_size >= system_ram)
ret = -EINVAL;
return ret;
}
/*
* Add a dummy early_param handler to mark crashkernel= as a known command line
* parameter and suppress incorrect warnings in init/main.c.
*/
static int __init parse_crashkernel_dummy(char *arg)
{
return 0;
}
early_param("crashkernel", parse_crashkernel_dummy);
#ifdef CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
static int __init reserve_crashkernel_low(unsigned long long low_size)
{
#ifdef CONFIG_64BIT
unsigned long long low_base;
low_base = memblock_phys_alloc_range(low_size, CRASH_ALIGN, 0, CRASH_ADDR_LOW_MAX);
if (!low_base) {
pr_err("cannot allocate crashkernel low memory (size:0x%llx).\n", low_size);
return -ENOMEM;
}
pr_info("crashkernel low memory reserved: 0x%08llx - 0x%08llx (%lld MB)\n",
low_base, low_base + low_size, low_size >> 20);
crashk_low_res.start = low_base;
crashk_low_res.end = low_base + low_size - 1;
#ifdef HAVE_ARCH_ADD_CRASH_RES_TO_IOMEM_EARLY
insert_resource(&iomem_resource, &crashk_low_res);
#endif
#endif
return 0;
}
void __init reserve_crashkernel_generic(char *cmdline,
unsigned long long crash_size,
unsigned long long crash_base,
unsigned long long crash_low_size,
bool high)
{
unsigned long long search_end = CRASH_ADDR_LOW_MAX, search_base = 0;
bool fixed_base = false;
/* User specifies base address explicitly. */
if (crash_base) {
fixed_base = true;
search_base = crash_base;
search_end = crash_base + crash_size;
} else if (high) {
search_base = CRASH_ADDR_LOW_MAX;
search_end = CRASH_ADDR_HIGH_MAX;
}
retry:
crash_base = memblock_phys_alloc_range(crash_size, CRASH_ALIGN,
search_base, search_end);
if (!crash_base) {
/*
* For crashkernel=size[KMG]@offset[KMG], print out failure
* message if can't reserve the specified region.
*/
if (fixed_base) {
pr_warn("crashkernel reservation failed - memory is in use.\n");
return;
}
/*
* For crashkernel=size[KMG], if the first attempt was for
* low memory, fall back to high memory, the minimum required
* low memory will be reserved later.
*/
if (!high && search_end == CRASH_ADDR_LOW_MAX) {
search_end = CRASH_ADDR_HIGH_MAX;
search_base = CRASH_ADDR_LOW_MAX;
crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE;
goto retry;
}
/*
* For crashkernel=size[KMG],high, if the first attempt was
* for high memory, fall back to low memory.
*/
if (high && search_end == CRASH_ADDR_HIGH_MAX) {
search_end = CRASH_ADDR_LOW_MAX;
search_base = 0;
if (search_end != CRASH_ADDR_HIGH_MAX)
goto retry;
}
pr_warn("cannot allocate crashkernel (size:0x%llx)\n",
crash_size);
return;
}
if ((crash_base >= CRASH_ADDR_LOW_MAX) &&
crash_low_size && reserve_crashkernel_low(crash_low_size)) {
memblock_phys_free(crash_base, crash_size);
return;
}
pr_info("crashkernel reserved: 0x%016llx - 0x%016llx (%lld MB)\n",
crash_base, crash_base + crash_size, crash_size >> 20);
/*
* The crashkernel memory will be removed from the kernel linear
* map. Inform kmemleak so that it won't try to access it.
*/
kmemleak_ignore_phys(crash_base);
if (crashk_low_res.end)
kmemleak_ignore_phys(crashk_low_res.start);
crashk_res.start = crash_base;
crashk_res.end = crash_base + crash_size - 1;
#ifdef HAVE_ARCH_ADD_CRASH_RES_TO_IOMEM_EARLY
insert_resource(&iomem_resource, &crashk_res);
#endif
}
#ifndef HAVE_ARCH_ADD_CRASH_RES_TO_IOMEM_EARLY
static __init int insert_crashkernel_resources(void)
{
if (crashk_res.start < crashk_res.end)
insert_resource(&iomem_resource, &crashk_res);
if (crashk_low_res.start < crashk_low_res.end)
insert_resource(&iomem_resource, &crashk_low_res);
return 0;
}
early_initcall(insert_crashkernel_resources);
#endif
#endif
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