diff options
Diffstat (limited to 'kexec/arch/arm64/crashdump-arm64.c')
| -rw-r--r-- | kexec/arch/arm64/crashdump-arm64.c | 248 |
1 files changed, 248 insertions, 0 deletions
diff --git a/kexec/arch/arm64/crashdump-arm64.c b/kexec/arch/arm64/crashdump-arm64.c new file mode 100644 index 0000000..3098315 --- /dev/null +++ b/kexec/arch/arm64/crashdump-arm64.c @@ -0,0 +1,248 @@ +/* + * ARM64 crashdump. + * partly derived from arm implementation + * + * Copyright (c) 2014-2017 Linaro Limited + * Author: AKASHI Takahiro <takahiro.akashi@linaro.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#define _GNU_SOURCE + +#include <errno.h> +#include <linux/elf.h> + +#include "kexec.h" +#include "crashdump.h" +#include "crashdump-arm64.h" +#include "iomem.h" +#include "kexec-arm64.h" +#include "kexec-elf.h" +#include "mem_regions.h" + +/* memory ranges of crashed kernel */ +static struct memory_ranges system_memory_rgns; + +/* memory range reserved for crashkernel */ +struct memory_range crash_reserved_mem[CRASH_MAX_RESERVED_RANGES]; +struct memory_ranges usablemem_rgns = { + .size = 0, + .max_size = CRASH_MAX_RESERVED_RANGES, + .ranges = crash_reserved_mem, +}; + +struct memory_range elfcorehdr_mem; + +static struct crash_elf_info elf_info = { + .class = ELFCLASS64, +#if (__BYTE_ORDER == __LITTLE_ENDIAN) + .data = ELFDATA2LSB, +#else + .data = ELFDATA2MSB, +#endif + .machine = EM_AARCH64, +}; + +/* + * iomem_range_callback() - callback called for each iomem region + * @data: not used + * @nr: not used + * @str: name of the memory region + * @base: start address of the memory region + * @length: size of the memory region + * + * This function is called once for each memory region found in /proc/iomem. + * It locates system RAM and crashkernel reserved memory and places these to + * variables, respectively, system_memory_rgns and usablemem_rgns. + */ + +static int iomem_range_callback(void *UNUSED(data), int UNUSED(nr), + char *str, unsigned long long base, + unsigned long long length) +{ + if (strncmp(str, CRASH_KERNEL, strlen(CRASH_KERNEL)) == 0) + return mem_regions_alloc_and_add(&usablemem_rgns, + base, length, RANGE_RAM); + else if (strncmp(str, SYSTEM_RAM, strlen(SYSTEM_RAM)) == 0) + return mem_regions_alloc_and_add(&system_memory_rgns, + base, length, RANGE_RAM); + else if (strncmp(str, KERNEL_CODE, strlen(KERNEL_CODE)) == 0) { + + unsigned long long kva_text = get_kernel_sym("_text"); + unsigned long long kva_stext = get_kernel_sym("_stext"); + unsigned long long kva_text_end = get_kernel_sym("__init_begin"); + + /* + * old: kernel_code.start = __pa_symbol(_text); + * new: kernel_code.start = __pa_symbol(_stext); + * + * For compatibility, deduce by comparing the gap "__init_begin - _stext" + * and the res size of "Kernel code" in /proc/iomem + */ + if (kva_text_end - kva_stext == length) + elf_info.kern_paddr_start = base - (kva_stext - kva_text); + else + elf_info.kern_paddr_start = base; + } + else if (strncmp(str, KERNEL_DATA, strlen(KERNEL_DATA)) == 0) + elf_info.kern_size = base + length - elf_info.kern_paddr_start; + + return 0; +} + +int is_crashkernel_mem_reserved(void) +{ + if (!usablemem_rgns.size) + kexec_iomem_for_each_line(NULL, iomem_range_callback, NULL); + + return usablemem_rgns.size; +} + +/* + * crash_get_memory_ranges() - read system physical memory + * + * Function reads through system physical memory and stores found memory + * regions in system_memory_ranges. + * Regions are sorted in ascending order. + * + * Returns 0 in case of success and a negative value otherwise. + */ +static int crash_get_memory_ranges(void) +{ + int i; + + /* + * First read all memory regions that can be considered as + * system memory including the crash area. + */ + if (!usablemem_rgns.size) + kexec_iomem_for_each_line(NULL, iomem_range_callback, NULL); + + /* allow one or two regions for crash dump kernel */ + if (!usablemem_rgns.size) + return -EINVAL; + + dbgprint_mem_range("Reserved memory range", + usablemem_rgns.ranges, usablemem_rgns.size); + + for (i = 0; i < usablemem_rgns.size; i++) { + if (mem_regions_alloc_and_exclude(&system_memory_rgns, + &crash_reserved_mem[i])) { + fprintf(stderr, "Cannot allocate memory for ranges\n"); + return -ENOMEM; + } + } + + /* + * Make sure that the memory regions are sorted. + */ + mem_regions_sort(&system_memory_rgns); + + dbgprint_mem_range("Coredump memory ranges", + system_memory_rgns.ranges, system_memory_rgns.size); + + /* + * For additional kernel code/data segment. + * kern_paddr_start/kern_size are determined in iomem_range_callback + */ + elf_info.kern_vaddr_start = get_kernel_sym("_text"); + if (!elf_info.kern_vaddr_start) + elf_info.kern_vaddr_start = UINT64_MAX; + + return 0; +} + +/* + * load_crashdump_segments() - load the elf core header + * @info: kexec info structure + * + * This function creates and loads an additional segment of elf core header + : which is used to construct /proc/vmcore on crash dump kernel. + * + * Return 0 in case of success and -1 in case of error. + */ + +int load_crashdump_segments(struct kexec_info *info) +{ + unsigned long elfcorehdr; + unsigned long bufsz; + void *buf; + int err; + + /* + * First fetch all the memory (RAM) ranges that we are going to + * pass to the crash dump kernel during panic. + */ + + err = crash_get_memory_ranges(); + + if (err) + return EFAILED; + + get_page_offset((unsigned long *)&elf_info.page_offset); + dbgprintf("%s: page_offset: %016llx\n", __func__, + elf_info.page_offset); + + err = crash_create_elf64_headers(info, &elf_info, + system_memory_rgns.ranges, system_memory_rgns.size, + &buf, &bufsz, ELF_CORE_HEADER_ALIGN); + + if (err) + return EFAILED; + + elfcorehdr = add_buffer_phys_virt(info, buf, bufsz, bufsz, 0, + crash_reserved_mem[usablemem_rgns.size - 1].start, + crash_reserved_mem[usablemem_rgns.size - 1].end, + -1, 0); + + elfcorehdr_mem.start = elfcorehdr; + elfcorehdr_mem.end = elfcorehdr + bufsz - 1; + + dbgprintf("%s: elfcorehdr 0x%llx-0x%llx\n", __func__, + elfcorehdr_mem.start, elfcorehdr_mem.end); + + return 0; +} + +/* + * e_entry and p_paddr are actually in virtual address space. + * Those values will be translated to physcal addresses by using + * virt_to_phys() in add_segment(). + * So let's fix up those values for later use so the memory base + * (arm64_mm.phys_offset) will be correctly replaced with + * crash_reserved_mem[usablemem_rgns.size - 1].start. + */ +void fixup_elf_addrs(struct mem_ehdr *ehdr) +{ + struct mem_phdr *phdr; + int i; + + ehdr->e_entry += -arm64_mem.phys_offset + + crash_reserved_mem[usablemem_rgns.size - 1].start; + + for (i = 0; i < ehdr->e_phnum; i++) { + phdr = &ehdr->e_phdr[i]; + if (phdr->p_type != PT_LOAD) + continue; + phdr->p_paddr += + (-arm64_mem.phys_offset + + crash_reserved_mem[usablemem_rgns.size - 1].start); + } +} + +int get_crash_kernel_load_range(uint64_t *start, uint64_t *end) +{ + if (!usablemem_rgns.size) + kexec_iomem_for_each_line(NULL, iomem_range_callback, NULL); + + if (!usablemem_rgns.size) + return -1; + + *start = crash_reserved_mem[usablemem_rgns.size - 1].start; + *end = crash_reserved_mem[usablemem_rgns.size - 1].end; + + return 0; +} |