| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * crash.c - kernel crash support code. |
| * Copyright (C) 2002-2004 Eric Biederman <ebiederm@xmission.com> |
| */ |
| |
| #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; |
| |
| 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; |
| 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 |