The quilt patch titled Subject: kexec: split crashkernel reservation code out from crash_core.c has been removed from the -mm tree. Its filename was kexec-split-crashkernel-reservation-code-out-from-crash_corec.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Baoquan He <bhe@xxxxxxxxxx> Subject: kexec: split crashkernel reservation code out from crash_core.c Date: Wed, 24 Jan 2024 13:12:41 +0800 Patch series "Split crash out from kexec and clean up related config items", v3. Motivation: ============= Previously, LKP reported a building error. When investigating, it can't be resolved reasonablly with the present messy kdump config items. https://lore.kernel.org/oe-kbuild-all/202312182200.Ka7MzifQ-lkp@xxxxxxxxx/ The kdump (crash dumping) related config items could causes confusions: Firstly, CRASH_CORE enables codes including - crashkernel reservation; - elfcorehdr updating; - vmcoreinfo exporting; - crash hotplug handling; Now fadump of powerpc, kcore dynamic debugging and kdump all selects CRASH_CORE, while fadump - fadump needs crashkernel parsing, vmcoreinfo exporting, and accessing global variable 'elfcorehdr_addr'; - kcore only needs vmcoreinfo exporting; - kdump needs all of the current kernel/crash_core.c. So only enabling PROC_CORE or FA_DUMP will enable CRASH_CORE, this mislead people that we enable crash dumping, actual it's not. Secondly, It's not reasonable to allow KEXEC_CORE select CRASH_CORE. Because KEXEC_CORE enables codes which allocate control pages, copy kexec/kdump segments, and prepare for switching. These codes are shared by both kexec reboot and kdump. We could want kexec reboot, but disable kdump. In that case, CRASH_CORE should not be selected. -------------------- CONFIG_CRASH_CORE=y CONFIG_KEXEC_CORE=y CONFIG_KEXEC=y CONFIG_KEXEC_FILE=y --------------------- Thirdly, It's not reasonable to allow CRASH_DUMP select KEXEC_CORE. That could make KEXEC_CORE, CRASH_DUMP are enabled independently from KEXEC or KEXEC_FILE. However, w/o KEXEC or KEXEC_FILE, the KEXEC_CORE code built in doesn't make any sense because no kernel loading or switching will happen to utilize the KEXEC_CORE code. --------------------- CONFIG_CRASH_CORE=y CONFIG_KEXEC_CORE=y CONFIG_CRASH_DUMP=y --------------------- In this case, what is worse, on arch sh and arm, KEXEC relies on MMU, while CRASH_DUMP can still be enabled when !MMU, then compiling error is seen as the lkp test robot reported in above link. ------arch/sh/Kconfig------ config ARCH_SUPPORTS_KEXEC def_bool MMU config ARCH_SUPPORTS_CRASH_DUMP def_bool BROKEN_ON_SMP --------------------------- Changes: =========== 1, split out crash_reserve.c from crash_core.c; 2, split out vmcore_infoc. from crash_core.c; 3, move crash related codes in kexec_core.c into crash_core.c; 4, remove dependency of FA_DUMP on CRASH_DUMP; 5, clean up kdump related config items; 6, wrap up crash codes in crash related ifdefs on all 8 arch-es which support crash dumping, except of ppc; Achievement: =========== With above changes, I can rearrange the config item logic as below (the right item depends on or is selected by the left item): PROC_KCORE -----------> VMCORE_INFO |----------> VMCORE_INFO FA_DUMP----| |----------> CRASH_RESERVE ---->VMCORE_INFO / |---->CRASH_RESERVE KEXEC --| /| |--> KEXEC_CORE--> CRASH_DUMP-->/-|---->PROC_VMCORE KEXEC_FILE --| \ | \---->CRASH_HOTPLUG KEXEC --| |--> KEXEC_CORE (for kexec reboot only) KEXEC_FILE --| Test ======== On all 8 architectures, including x86_64, arm64, s390x, sh, arm, mips, riscv, loongarch, I did below three cases of config item setting and building all passed. Take configs on x86_64 as exampmle here: (1) Both CONFIG_KEXEC and KEXEC_FILE is unset, then all kexec/kdump items are unset automatically: # Kexec and crash features # CONFIG_KEXEC is not set # CONFIG_KEXEC_FILE is not set # end of Kexec and crash features (2) set CONFIG_KEXEC_FILE and 'make olddefconfig': --------------- # Kexec and crash features CONFIG_CRASH_RESERVE=y CONFIG_VMCORE_INFO=y CONFIG_KEXEC_CORE=y CONFIG_KEXEC_FILE=y CONFIG_CRASH_DUMP=y CONFIG_CRASH_HOTPLUG=y CONFIG_CRASH_MAX_MEMORY_RANGES=8192 # end of Kexec and crash features --------------- (3) unset CONFIG_CRASH_DUMP in case 2 and execute 'make olddefconfig': ------------------------ # Kexec and crash features CONFIG_KEXEC_CORE=y CONFIG_KEXEC_FILE=y # end of Kexec and crash features ------------------------ Note: For ppc, it needs investigation to make clear how to split out crash code in arch folder. Hope Hari and Pingfan can help have a look, see if it's doable. Now, I make it either have both kexec and crash enabled, or disable both of them altogether. This patch (of 14): Both kdump and fa_dump of ppc rely on crashkernel reservation. Move the relevant codes into separate files: crash_reserve.c, include/linux/crash_reserve.h. And also add config item CRASH_RESERVE to control its enabling of the codes. And update config items which has relationship with crashkernel reservation. And also change ifdeffery from CONFIG_CRASH_CORE to CONFIG_CRASH_RESERVE when those scopes are only crashkernel reservation related. And also rename arch/XXX/include/asm/{crash_core.h => crash_reserve.h} on arm64, x86 and risc-v because those architectures' crash_core.h is only related to crashkernel reservation. [akpm@xxxxxxxxxxxxxxxxxxxx: s/CRASH_RESEERVE/CRASH_RESERVE/, per Klara Modin] Link: https://lkml.kernel.org/r/20240124051254.67105-1-bhe@xxxxxxxxxx Link: https://lkml.kernel.org/r/20240124051254.67105-2-bhe@xxxxxxxxxx Signed-off-by: Baoquan He <bhe@xxxxxxxxxx> Acked-by: Hari Bathini <hbathini@xxxxxxxxxxxxx> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Eric W. Biederman <ebiederm@xxxxxxxxxxxx> Cc: Pingfan Liu <piliu@xxxxxxxxxx> Cc: Klara Modin <klarasmodin@xxxxxxxxx> Cc: Michael Kelley <mhklinux@xxxxxxxxxxx> Cc: Nathan Chancellor <nathan@xxxxxxxxxx> Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> Cc: Yang Li <yang.lee@xxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/arm64/Kconfig | 2 arch/arm64/include/asm/crash_core.h | 10 arch/arm64/include/asm/crash_reserve.h | 10 arch/powerpc/Kconfig | 1 arch/powerpc/mm/nohash/kaslr_booke.c | 4 arch/riscv/Kconfig | 2 arch/riscv/include/asm/crash_core.h | 11 arch/riscv/include/asm/crash_reserve.h | 11 arch/x86/Kconfig | 2 arch/x86/include/asm/crash_core.h | 42 -- arch/x86/include/asm/crash_reserve.h | 42 ++ include/linux/crash_core.h | 40 - include/linux/crash_reserve.h | 48 ++ include/linux/kexec.h | 1 kernel/Kconfig.kexec | 5 kernel/Makefile | 1 kernel/crash_core.c | 438 --------------------- kernel/crash_reserve.c | 464 +++++++++++++++++++++++ 18 files changed, 587 insertions(+), 547 deletions(-) --- a/arch/arm64/include/asm/crash_core.h +++ /dev/null @@ -1,10 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-only */ -#ifndef _ARM64_CRASH_CORE_H -#define _ARM64_CRASH_CORE_H - -/* Current arm64 boot protocol requires 2MB alignment */ -#define CRASH_ALIGN SZ_2M - -#define CRASH_ADDR_LOW_MAX arm64_dma_phys_limit -#define CRASH_ADDR_HIGH_MAX (PHYS_MASK + 1) -#endif --- /dev/null +++ a/arch/arm64/include/asm/crash_reserve.h @@ -0,0 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef _ARM64_CRASH_RESERVE_H +#define _ARM64_CRASH_RESERVE_H + +/* Current arm64 boot protocol requires 2MB alignment */ +#define CRASH_ALIGN SZ_2M + +#define CRASH_ADDR_LOW_MAX arm64_dma_phys_limit +#define CRASH_ADDR_HIGH_MAX (PHYS_MASK + 1) +#endif --- a/arch/arm64/Kconfig~kexec-split-crashkernel-reservation-code-out-from-crash_corec +++ a/arch/arm64/Kconfig @@ -1519,7 +1519,7 @@ config ARCH_SUPPORTS_CRASH_DUMP def_bool y config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION - def_bool CRASH_CORE + def_bool CRASH_RESERVE config TRANS_TABLE def_bool y --- a/arch/powerpc/Kconfig~kexec-split-crashkernel-reservation-code-out-from-crash_corec +++ a/arch/powerpc/Kconfig @@ -691,6 +691,7 @@ config FA_DUMP bool "Firmware-assisted dump" depends on PPC64 && (PPC_RTAS || PPC_POWERNV) select CRASH_CORE + select CRASH_RESERVE select CRASH_DUMP help A robust mechanism to get reliable kernel crash dump with --- a/arch/powerpc/mm/nohash/kaslr_booke.c~kexec-split-crashkernel-reservation-code-out-from-crash_corec +++ a/arch/powerpc/mm/nohash/kaslr_booke.c @@ -13,7 +13,7 @@ #include <linux/delay.h> #include <linux/memblock.h> #include <linux/libfdt.h> -#include <linux/crash_core.h> +#include <linux/crash_reserve.h> #include <linux/of.h> #include <linux/of_fdt.h> #include <asm/cacheflush.h> @@ -173,7 +173,7 @@ static __init bool overlaps_region(const static void __init get_crash_kernel(void *fdt, unsigned long size) { -#ifdef CONFIG_CRASH_CORE +#ifdef CONFIG_CRASH_RESERVE unsigned long long crash_size, crash_base; int ret; --- a/arch/riscv/include/asm/crash_core.h +++ /dev/null @@ -1,11 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-only */ -#ifndef _RISCV_CRASH_CORE_H -#define _RISCV_CRASH_CORE_H - -#define CRASH_ALIGN PMD_SIZE - -#define CRASH_ADDR_LOW_MAX dma32_phys_limit -#define CRASH_ADDR_HIGH_MAX memblock_end_of_DRAM() - -extern phys_addr_t memblock_end_of_DRAM(void); -#endif --- /dev/null +++ a/arch/riscv/include/asm/crash_reserve.h @@ -0,0 +1,11 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef _RISCV_CRASH_RESERVE_H +#define _RISCV_CRASH_RESERVE_H + +#define CRASH_ALIGN PMD_SIZE + +#define CRASH_ADDR_LOW_MAX dma32_phys_limit +#define CRASH_ADDR_HIGH_MAX memblock_end_of_DRAM() + +extern phys_addr_t memblock_end_of_DRAM(void); +#endif --- a/arch/riscv/Kconfig~kexec-split-crashkernel-reservation-code-out-from-crash_corec +++ a/arch/riscv/Kconfig @@ -767,7 +767,7 @@ config ARCH_SUPPORTS_CRASH_DUMP def_bool y config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION - def_bool CRASH_CORE + def_bool CRASH_RESERVE config COMPAT bool "Kernel support for 32-bit U-mode" --- a/arch/x86/include/asm/crash_core.h +++ /dev/null @@ -1,42 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#ifndef _X86_CRASH_CORE_H -#define _X86_CRASH_CORE_H - -/* 16M alignment for crash kernel regions */ -#define CRASH_ALIGN SZ_16M - -/* - * Keep the crash kernel below this limit. - * - * Earlier 32-bits kernels would limit the kernel to the low 512 MB range - * due to mapping restrictions. - * - * 64-bit kdump kernels need to be restricted to be under 64 TB, which is - * the upper limit of system RAM in 4-level paging mode. Since the kdump - * jump could be from 5-level paging to 4-level paging, the jump will fail if - * the kernel is put above 64 TB, and during the 1st kernel bootup there's - * no good way to detect the paging mode of the target kernel which will be - * loaded for dumping. - */ -extern unsigned long swiotlb_size_or_default(void); - -#ifdef CONFIG_X86_32 -# define CRASH_ADDR_LOW_MAX SZ_512M -# define CRASH_ADDR_HIGH_MAX SZ_512M -#else -# define CRASH_ADDR_LOW_MAX SZ_4G -# define CRASH_ADDR_HIGH_MAX SZ_64T -#endif - -# define DEFAULT_CRASH_KERNEL_LOW_SIZE crash_low_size_default() - -static inline unsigned long crash_low_size_default(void) -{ -#ifdef CONFIG_X86_64 - return max(swiotlb_size_or_default() + (8UL << 20), 256UL << 20); -#else - return 0; -#endif -} - -#endif /* _X86_CRASH_CORE_H */ --- /dev/null +++ a/arch/x86/include/asm/crash_reserve.h @@ -0,0 +1,42 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _X86_CRASH_RESERVE_H +#define _X86_CRASH_RESERVE_H + +/* 16M alignment for crash kernel regions */ +#define CRASH_ALIGN SZ_16M + +/* + * Keep the crash kernel below this limit. + * + * Earlier 32-bits kernels would limit the kernel to the low 512 MB range + * due to mapping restrictions. + * + * 64-bit kdump kernels need to be restricted to be under 64 TB, which is + * the upper limit of system RAM in 4-level paging mode. Since the kdump + * jump could be from 5-level paging to 4-level paging, the jump will fail if + * the kernel is put above 64 TB, and during the 1st kernel bootup there's + * no good way to detect the paging mode of the target kernel which will be + * loaded for dumping. + */ +extern unsigned long swiotlb_size_or_default(void); + +#ifdef CONFIG_X86_32 +# define CRASH_ADDR_LOW_MAX SZ_512M +# define CRASH_ADDR_HIGH_MAX SZ_512M +#else +# define CRASH_ADDR_LOW_MAX SZ_4G +# define CRASH_ADDR_HIGH_MAX SZ_64T +#endif + +# define DEFAULT_CRASH_KERNEL_LOW_SIZE crash_low_size_default() + +static inline unsigned long crash_low_size_default(void) +{ +#ifdef CONFIG_X86_64 + return max(swiotlb_size_or_default() + (8UL << 20), 256UL << 20); +#else + return 0; +#endif +} + +#endif /* _X86_CRASH_RESERVE_H */ --- a/arch/x86/Kconfig~kexec-split-crashkernel-reservation-code-out-from-crash_corec +++ a/arch/x86/Kconfig @@ -2106,7 +2106,7 @@ config ARCH_SUPPORTS_CRASH_HOTPLUG def_bool y config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION - def_bool CRASH_CORE + def_bool CRASH_RESERVE config PHYSICAL_START hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) --- a/include/linux/crash_core.h~kexec-split-crashkernel-reservation-code-out-from-crash_corec +++ a/include/linux/crash_core.h @@ -5,14 +5,6 @@ #include <linux/linkage.h> #include <linux/elfcore.h> #include <linux/elf.h> -#ifdef CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION -#include <asm/crash_core.h> -#endif - -/* Location of a reserved region to hold the crash kernel. - */ -extern struct resource crashk_res; -extern struct resource crashk_low_res; #define CRASH_CORE_NOTE_NAME "CORE" #define CRASH_CORE_NOTE_HEAD_BYTES ALIGN(sizeof(struct elf_note), 4) @@ -87,38 +79,6 @@ Elf_Word *append_elf_note(Elf_Word *buf, void *data, size_t data_len); void final_note(Elf_Word *buf); -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); - -#ifdef CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION -#ifndef DEFAULT_CRASH_KERNEL_LOW_SIZE -#define DEFAULT_CRASH_KERNEL_LOW_SIZE (128UL << 20) -#endif -#ifndef CRASH_ALIGN -#define CRASH_ALIGN SZ_2M -#endif -#ifndef CRASH_ADDR_LOW_MAX -#define CRASH_ADDR_LOW_MAX SZ_4G -#endif -#ifndef CRASH_ADDR_HIGH_MAX -#define CRASH_ADDR_HIGH_MAX memblock_end_of_DRAM() -#endif - -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); -#else -static inline 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) -{} -#endif - /* Alignment required for elf header segment */ #define ELF_CORE_HEADER_ALIGN 4096 --- /dev/null +++ a/include/linux/crash_reserve.h @@ -0,0 +1,48 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef LINUX_CRASH_RESERVE_H +#define LINUX_CRASH_RESERVE_H + +#include <linux/linkage.h> +#include <linux/elfcore.h> +#include <linux/elf.h> +#ifdef CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION +#include <asm/crash_reserve.h> +#endif + +/* Location of a reserved region to hold the crash kernel. + */ +extern struct resource crashk_res; +extern struct resource crashk_low_res; + +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); + +#ifdef CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION +#ifndef DEFAULT_CRASH_KERNEL_LOW_SIZE +#define DEFAULT_CRASH_KERNEL_LOW_SIZE (128UL << 20) +#endif +#ifndef CRASH_ALIGN +#define CRASH_ALIGN SZ_2M +#endif +#ifndef CRASH_ADDR_LOW_MAX +#define CRASH_ADDR_LOW_MAX SZ_4G +#endif +#ifndef CRASH_ADDR_HIGH_MAX +#define CRASH_ADDR_HIGH_MAX memblock_end_of_DRAM() +#endif + +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); +#else +static inline 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) +{} +#endif +#endif /* LINUX_CRASH_RESERVE_H */ --- a/include/linux/kexec.h~kexec-split-crashkernel-reservation-code-out-from-crash_corec +++ a/include/linux/kexec.h @@ -16,6 +16,7 @@ #if !defined(__ASSEMBLY__) #include <linux/crash_core.h> +#include <linux/crash_reserve.h> #include <asm/io.h> #include <linux/range.h> --- a/kernel/crash_core.c~kexec-split-crashkernel-reservation-code-out-from-crash_corec +++ a/kernel/crash_core.c @@ -34,444 +34,6 @@ u32 *vmcoreinfo_note; /* trusted vmcoreinfo, e.g. we can make a copy in the crash memory */ static unsigned char *vmcoreinfo_data_safecopy; -/* 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("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("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; -#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; -} - -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 - int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map, void **addr, unsigned long *sz) { --- /dev/null +++ a/kernel/crash_reserve.c @@ -0,0 +1,464 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * crash.c - kernel crash support code. + * Copyright (C) 2002-2004 Eric Biederman <ebiederm@xxxxxxxxxxxx> + */ + +#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/kexec.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("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("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; + insert_resource(&iomem_resource, &crashk_low_res); +#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; +} + +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 --- a/kernel/Kconfig.kexec~kexec-split-crashkernel-reservation-code-out-from-crash_corec +++ a/kernel/Kconfig.kexec @@ -2,11 +2,15 @@ menu "Kexec and crash features" +config CRASH_RESERVE + bool + config CRASH_CORE bool config KEXEC_CORE select CRASH_CORE + select CRASH_RESERVE bool config KEXEC_ELF @@ -96,7 +100,6 @@ config KEXEC_JUMP config CRASH_DUMP bool "kernel crash dumps" depends on ARCH_SUPPORTS_CRASH_DUMP - select CRASH_CORE select KEXEC_CORE help Generate crash dump after being started by kexec. --- a/kernel/Makefile~kexec-split-crashkernel-reservation-code-out-from-crash_corec +++ a/kernel/Makefile @@ -69,6 +69,7 @@ obj-$(CONFIG_KALLSYMS) += kallsyms.o obj-$(CONFIG_KALLSYMS_SELFTEST) += kallsyms_selftest.o obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o obj-$(CONFIG_CRASH_CORE) += crash_core.o +obj-$(CONFIG_CRASH_RESERVE) += crash_reserve.o obj-$(CONFIG_KEXEC_CORE) += kexec_core.o obj-$(CONFIG_KEXEC) += kexec.o obj-$(CONFIG_KEXEC_FILE) += kexec_file.o _ Patches currently in -mm which might be from bhe@xxxxxxxxxx are