diff options
Diffstat (limited to 'kexec/crashdump-elf.c')
| -rw-r--r-- | kexec/crashdump-elf.c | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/kexec/crashdump-elf.c b/kexec/crashdump-elf.c new file mode 100644 index 0000000..9e3121f --- /dev/null +++ b/kexec/crashdump-elf.c @@ -0,0 +1,184 @@ + +#if !defined(FUNC) || !defined(EHDR) || !defined(PHDR) +#error FUNC, EHDR and PHDR must be defined +#endif + +/* Prepares the crash memory headers and stores in supplied buffer. */ +int FUNC(struct kexec_info *info, + struct crash_elf_info *elf_info, + struct memory_range *range, int ranges, + void **buf, unsigned long *size) +{ + EHDR *elf; + PHDR *phdr; + int i, sz; + char *bufp; + long int nr_cpus = 0; + int align = 1024; + uint64_t notes_addr, notes_len; + int (*get_note_info)(int cpu, uint64_t *addr, uint64_t *len); + + nr_cpus = sysconf(_SC_NPROCESSORS_CONF); + if (nr_cpus < 0) { + return -1; + } + + sz = sizeof(EHDR) + nr_cpus * sizeof(PHDR) + ranges * sizeof(PHDR); + + /* + * Certain architectures such as x86_64 and ia64 require a separate + * PT_LOAD program header for the kernel. This is controlled through + * info->kern_size. + * + * The separate PT_LOAD program header is required either because the + * kernel is mapped at a different location than the rest of the + * physical memory or because we need to support relocatable kernels. + * Or both as on x86_64. + * + * In the relocatable kernel case this PT_LOAD segment is used to tell + * where the kernel was actually loaded which may be different from + * the load address present in the vmlinux file. + * + * The extra kernel PT_LOAD program header results in a vmcore file + * which is larger than the size of the physical memory. This is + * because the memory for the kernel is present both in the kernel + * PT_LOAD program header and in the physical RAM program headers. + */ + + if (info->kern_size) { + sz += sizeof(PHDR); + } + + sz += align - 1; + sz &= ~(align - 1); + + bufp = xmalloc(sz); + memset(bufp, 0, sz); + + *buf = bufp; + *size = sz; + + /* Setup ELF Header*/ + elf = (EHDR *) bufp; + bufp += sizeof(EHDR); + memcpy(elf->e_ident, ELFMAG, SELFMAG); + elf->e_ident[EI_CLASS] = elf_info->class; + elf->e_ident[EI_DATA] = elf_info->data; + elf->e_ident[EI_VERSION]= EV_CURRENT; + elf->e_ident[EI_OSABI] = ELFOSABI_NONE; + memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); + elf->e_type = ET_CORE; + elf->e_machine = elf_info->machine; + elf->e_version = EV_CURRENT; + elf->e_entry = 0; + elf->e_phoff = sizeof(EHDR); + elf->e_shoff = 0; + elf->e_flags = 0; + elf->e_ehsize = sizeof(EHDR); + elf->e_phentsize= sizeof(PHDR); + elf->e_phnum = 0; + elf->e_shentsize= 0; + elf->e_shnum = 0; + elf->e_shstrndx = 0; + + /* Default way to get crash notes is by get_crash_notes_per_cpu() */ + + get_note_info = elf_info->get_note_info; + if (!get_note_info) + get_note_info = get_crash_notes_per_cpu; + + /* PT_NOTE program headers. One per cpu */ + + for (i = 0; i < nr_cpus; i++) { + if (get_note_info(i, ¬es_addr, ¬es_len) < 0) { + /* This cpu is not present. Skip it. */ + continue; + } + + phdr = (PHDR *) bufp; + bufp += sizeof(PHDR); + phdr->p_type = PT_NOTE; + phdr->p_flags = 0; + phdr->p_offset = phdr->p_paddr = notes_addr; + phdr->p_vaddr = 0; + phdr->p_filesz = phdr->p_memsz = notes_len; + /* Do we need any alignment of segments? */ + phdr->p_align = 0; + + /* Increment number of program headers. */ + (elf->e_phnum)++; + dfprintf(stdout, "Elf header: p_type = %d, p_offset = 0x%lx " + "p_paddr = 0x%lx p_vaddr = 0x%lx " + "p_filesz = 0x%lx p_memsz = 0x%lx\n", + phdr->p_type, phdr->p_offset, phdr->p_paddr, + phdr->p_vaddr, phdr->p_filesz, phdr->p_memsz); + } + + /* Setup an PT_LOAD type program header for the region where + * Kernel is mapped if info->kern_size is non-zero. + */ + + if (info->kern_size) { + phdr = (PHDR *) bufp; + bufp += sizeof(PHDR); + phdr->p_type = PT_LOAD; + phdr->p_flags = PF_R|PF_W|PF_X; + phdr->p_offset = phdr->p_paddr = info->kern_paddr_start; + phdr->p_vaddr = info->kern_vaddr_start; + phdr->p_filesz = phdr->p_memsz = info->kern_size; + phdr->p_align = 0; + (elf->e_phnum)++; + dfprintf(stdout, "Kernel text Elf header: " + "p_type = %d, p_offset = 0x%lx " + "p_paddr = 0x%lx p_vaddr = 0x%lx " + "p_filesz = 0x%lx p_memsz = 0x%lx\n", + phdr->p_type, phdr->p_offset, phdr->p_paddr, + phdr->p_vaddr, phdr->p_filesz, phdr->p_memsz); + } + + /* Setup PT_LOAD type program header for every system RAM chunk. + * A seprate program header for Backup Region*/ + for (i = 0; i < ranges; i++, range++) { + unsigned long long mstart, mend; + if (range->type != RANGE_RAM) + continue; + mstart = range->start; + mend = range->end; + if (!mstart && !mend) + continue; + phdr = (PHDR *) bufp; + bufp += sizeof(PHDR); + phdr->p_type = PT_LOAD; + phdr->p_flags = PF_R|PF_W|PF_X; + phdr->p_offset = mstart; + + if (mstart == elf_info->backup_src_start + && mend == elf_info->backup_src_end) + phdr->p_offset = info->backup_start; + + /* We already prepared the header for kernel text. Map + * rest of the memory segments to kernel linearly mapped + * memory region. + */ + phdr->p_paddr = mstart; + phdr->p_vaddr = mstart + elf_info->page_offset; + phdr->p_filesz = phdr->p_memsz = mend - mstart + 1; + /* Do we need any alignment of segments? */ + phdr->p_align = 0; + + /* HIGMEM has a virtual address of -1 */ + + if (elf_info->lowmem_limit + && (mend > (elf_info->lowmem_limit - 1))) + phdr->p_vaddr = -1; + + /* Increment number of program headers. */ + (elf->e_phnum)++; + dfprintf(stdout, "Elf header: p_type = %d, p_offset = 0x%lx " + "p_paddr = 0x%lx p_vaddr = 0x%lx " + "p_filesz = 0x%lx p_memsz = 0x%lx\n", + phdr->p_type, phdr->p_offset, phdr->p_paddr, + phdr->p_vaddr, phdr->p_filesz, phdr->p_memsz); + } + return 0; +} |