/* * fs/proc/vmcore.c Interface for accessing the crash * dump from the system's previous life. * Heavily borrowed from fs/proc/kcore.c * Created by: Hariprasad Nellitheertha (hari@in.ibm.com) * Copyright (C) IBM Corporation, 2004. All rights reserved * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "internal.h" /* List representing chunks of contiguous memory areas and their offsets in * vmcore file. */ static LIST_HEAD(vmcore_list); /* Stores the pointer to the buffer containing kernel elf core headers. */ static char *elfcorebuf; static size_t elfcorebuf_sz; static size_t elfcorebuf_sz_orig; static char *elfnotes_buf; static size_t elfnotes_sz; /* Total size of vmcore file. */ static u64 vmcore_size; static struct proc_dir_entry *proc_vmcore = NULL; /* * Returns > 0 for RAM pages, 0 for non-RAM pages, < 0 on error * The called function has to take care of module refcounting. */ static int (*oldmem_pfn_is_ram)(unsigned long pfn); int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn)) { if (oldmem_pfn_is_ram) return -EBUSY; oldmem_pfn_is_ram = fn; return 0; } EXPORT_SYMBOL_GPL(register_oldmem_pfn_is_ram); void unregister_oldmem_pfn_is_ram(void) { oldmem_pfn_is_ram = NULL; wmb(); } EXPORT_SYMBOL_GPL(unregister_oldmem_pfn_is_ram); static int pfn_is_ram(unsigned long pfn) { int (*fn)(unsigned long pfn); /* pfn is ram unless fn() checks pagetype */ int ret = 1; /* * Ask hypervisor if the pfn is really ram. * A ballooned page contains no data and reading from such a page * will cause high load in the hypervisor. */ fn = oldmem_pfn_is_ram; if (fn) ret = fn(pfn); return ret; } /* Reads a page from the oldmem device from given offset. */ static ssize_t read_from_oldmem(char *buf, size_t count, u64 *ppos, int userbuf) { unsigned long pfn, offset; size_t nr_bytes; ssize_t read = 0, tmp; if (!count) return 0; offset = (unsigned long)(*ppos % PAGE_SIZE); pfn = (unsigned long)(*ppos / PAGE_SIZE); do { if (count > (PAGE_SIZE - offset)) nr_bytes = PAGE_SIZE - offset; else nr_bytes = count; /* If pfn is not ram, return zeros for sparse dump files */ if (pfn_is_ram(pfn) == 0) memset(buf, 0, nr_bytes); else { tmp = copy_oldmem_page(pfn, buf, nr_bytes, offset, userbuf); if (tmp < 0) return tmp; } *ppos += nr_bytes; count -= nr_bytes; buf += nr_bytes; read += nr_bytes; ++pfn; offset = 0; } while (count); return read; } /* Read from the ELF header and then the crash dump. On error, negative value is * returned otherwise number of bytes read are returned. */ static ssize_t read_vmcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos) { ssize_t acc = 0, tmp; size_t tsz; u64 start; struct vmcore *m = NULL; if (buflen == 0 || *fpos >= vmcore_size) return 0; /* trim buflen to not go beyond EOF */ if (buflen > vmcore_size - *fpos) buflen = vmcore_size - *fpos; /* Read ELF core header */ if (*fpos < elfcorebuf_sz) { tsz = min(elfcorebuf_sz - (size_t)*fpos, buflen); if (copy_to_user(buffer, elfcorebuf + *fpos, tsz)) return -EFAULT; buflen -= tsz; *fpos += tsz; buffer += tsz; acc += tsz; /* leave now if filled buffer already */ if (buflen == 0) return acc; } /* Read Elf note segment */ if (*fpos < elfcorebuf_sz + elfnotes_sz) { void *kaddr; tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)*fpos, buflen); kaddr = elfnotes_buf + *fpos - elfcorebuf_sz; if (copy_to_user(buffer, kaddr, tsz)) return -EFAULT; buflen -= tsz; *fpos += tsz; buffer += tsz; acc += tsz; /* leave now if filled buffer already */ if (buflen == 0) return acc; } list_for_each_entry(m, &vmcore_list, list) { if (*fpos < m->offset + m->size) { tsz = min_t(size_t, m->offset + m->size - *fpos, buflen); start = m->paddr + *fpos - m->offset; tmp = read_from_oldmem(buffer, tsz, &start, 1); if (tmp < 0) return tmp; buflen -= tsz; *fpos += tsz; buffer += tsz; acc += tsz; /* leave now if filled buffer already */ if (buflen == 0) return acc; } } return acc; } static const struct file_operations proc_vmcore_operations = { .read = read_vmcore, .llseek = default_llseek, }; static struct vmcore* __init get_new_element(void) { return kzalloc(sizeof(struct vmcore), GFP_KERNEL); } static u64 __init get_vmcore_size_elf64(char *elfptr, size_t elfsz) { int i; u64 size; Elf64_Ehdr *ehdr_ptr; Elf64_Phdr *phdr_ptr; ehdr_ptr = (Elf64_Ehdr *)elfptr; phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); size = elfsz; for (i = 0; i < ehdr_ptr->e_phnum; i++) { size += phdr_ptr->p_memsz; phdr_ptr++; } return size; } static u64 __init get_vmcore_size_elf32(char *elfptr, size_t elfsz) { int i; u64 size; Elf32_Ehdr *ehdr_ptr; Elf32_Phdr *phdr_ptr; ehdr_ptr = (Elf32_Ehdr *)elfptr; phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); size = elfsz; for (i = 0; i < ehdr_ptr->e_phnum; i++) { size += phdr_ptr->p_memsz; phdr_ptr++; } return size; } /** * update_note_header_size_elf64 - update p_memsz member of each PT_NOTE entry * * @ehdr_ptr: ELF header * * This function updates p_memsz member of each PT_NOTE entry in the * program header table pointed to by @ehdr_ptr to real size of ELF * note segment. */ static int __init update_note_header_size_elf64(const Elf64_Ehdr *ehdr_ptr) { int i, rc=0; Elf64_Phdr *phdr_ptr; Elf64_Nhdr *nhdr_ptr; phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1); for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { void *notes_section; u64 offset, max_sz, sz, real_sz = 0; if (phdr_ptr->p_type != PT_NOTE) continue; max_sz = phdr_ptr->p_memsz; offset = phdr_ptr->p_offset; notes_section = kmalloc(max_sz, GFP_KERNEL); if (!notes_section) return -ENOMEM; rc = read_from_oldmem(notes_section, max_sz, &offset, 0); if (rc < 0) { kfree(notes_section); return rc; } nhdr_ptr = notes_section; while (real_sz < max_sz) { if (nhdr_ptr->n_namesz == 0) break; sz = sizeof(Elf64_Nhdr) + ((nhdr_ptr->n_namesz + 3) & ~3) + ((nhdr_ptr->n_descsz + 3) & ~3); real_sz += sz; nhdr_ptr = (Elf64_Nhdr*)((char*)nhdr_ptr + sz); } kfree(notes_section); phdr_ptr->p_memsz = real_sz; } return 0; } /** * get_note_number_and_size_elf64 - get the number of PT_NOTE program * headers and sum of real size of their ELF note segment headers and * data. * * @ehdr_ptr: ELF header * @nr_ptnote: buffer for the number of PT_NOTE program headers * @sz_ptnote: buffer for size of unique PT_NOTE program header * * This function is used to merge multiple PT_NOTE program headers * into a unique single one. The resulting unique entry will have * @sz_ptnote in its phdr->p_mem. * * It is assumed that program headers with PT_NOTE type pointed to by * @ehdr_ptr has already been updated by update_note_header_size_elf64 * and each of PT_NOTE program headers has actual ELF note segment * size in its p_memsz member. */ static int __init get_note_number_and_size_elf64(const Elf64_Ehdr *ehdr_ptr, int *nr_ptnote, u64 *sz_ptnote) { int i; Elf64_Phdr *phdr_ptr; *nr_ptnote = *sz_ptnote = 0; phdr_ptr = (Elf64_Phdr *)(ehdr_ptr + 1); for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { if (phdr_ptr->p_type != PT_NOTE) continue; *nr_ptnote += 1; *sz_ptnote += phdr_ptr->p_memsz; } return 0; } /** * copy_notes_elf64 - copy ELF note segments in a given buffer * * @ehdr_ptr: ELF header * @notes_buf: buffer into which ELF note segments are copied * * This function is used to copy ELF note segment in the 1st kernel * into the buffer @notes_buf in the 2nd kernel. It is assumed that * size of the buffer @notes_buf is equal to or larger than sum of the * real ELF note segment headers and data. * * It is assumed that program headers with PT_NOTE type pointed to by * @ehdr_ptr has already been updated by update_note_header_size_elf64 * and each of PT_NOTE program headers has actual ELF note segment * size in its p_memsz member. */ static int __init copy_notes_elf64(const Elf64_Ehdr *ehdr_ptr, char *notes_buf) { int i, rc=0; Elf64_Phdr *phdr_ptr; phdr_ptr = (Elf64_Phdr*)(ehdr_ptr + 1); for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { u64 offset; if (phdr_ptr->p_type != PT_NOTE) continue; offset = phdr_ptr->p_offset; rc = read_from_oldmem(notes_buf, phdr_ptr->p_memsz, &offset, 0); if (rc < 0) return rc; notes_buf += phdr_ptr->p_memsz; } return 0; } /* Merges all the PT_NOTE headers into one. */ static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz, char **notes_buf, size_t *notes_sz) { int i, nr_ptnote=0, rc=0; char *tmp; Elf64_Ehdr *ehdr_ptr; Elf64_Phdr phdr; u64 phdr_sz = 0, note_off; struct vm_struct *vm; ehdr_ptr = (Elf64_Ehdr *)elfptr; rc = update_note_header_size_elf64(ehdr_ptr); if (rc < 0) return rc; rc = get_note_number_and_size_elf64(ehdr_ptr, &nr_ptnote, &phdr_sz); if (rc < 0) return rc; *notes_sz = roundup(phdr_sz, PAGE_SIZE); *notes_buf = vzalloc(*notes_sz); if (!*notes_buf) return -ENOMEM; /* * Allow users to remap ELF note segment buffer on vmalloc memory using * remap_vmalloc_range.() */ vm = find_vm_area(*notes_buf); BUG_ON(!vm); vm->flags |= VM_USERMAP; rc = copy_notes_elf64(ehdr_ptr, *notes_buf); if (rc < 0) return rc; /* Prepare merged PT_NOTE program header. */ phdr.p_type = PT_NOTE; phdr.p_flags = 0; note_off = sizeof(Elf64_Ehdr) + (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf64_Phdr); phdr.p_offset = roundup(note_off, PAGE_SIZE); phdr.p_vaddr = phdr.p_paddr = 0; phdr.p_filesz = phdr.p_memsz = phdr_sz; phdr.p_align = 0; /* Add merged PT_NOTE program header*/ tmp = elfptr + sizeof(Elf64_Ehdr); memcpy(tmp, &phdr, sizeof(phdr)); tmp += sizeof(phdr); /* Remove unwanted PT_NOTE program headers. */ i = (nr_ptnote - 1) * sizeof(Elf64_Phdr); *elfsz = *elfsz - i; memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf64_Ehdr)-sizeof(Elf64_Phdr))); memset(elfptr + *elfsz, 0, i); *elfsz = roundup(*elfsz, PAGE_SIZE); /* Modify e_phnum to reflect merged headers. */ ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1; return 0; } /** * update_note_header_size_elf32 - update p_memsz member of each PT_NOTE entry * * @ehdr_ptr: ELF header * * This function updates p_memsz member of each PT_NOTE entry in the * program header table pointed to by @ehdr_ptr to real size of ELF * note segment. */ static int __init update_note_header_size_elf32(const Elf32_Ehdr *ehdr_ptr) { int i, rc=0; Elf32_Phdr *phdr_ptr; Elf32_Nhdr *nhdr_ptr; phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1); for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { void *notes_section; u64 offset, max_sz, sz, real_sz = 0; if (phdr_ptr->p_type != PT_NOTE) continue; max_sz = phdr_ptr->p_memsz; offset = phdr_ptr->p_offset; notes_section = kmalloc(max_sz, GFP_KERNEL); if (!notes_section) return -ENOMEM; rc = read_from_oldmem(notes_section, max_sz, &offset, 0); if (rc < 0) { kfree(notes_section); return rc; } nhdr_ptr = notes_section; while (real_sz < max_sz) { if (nhdr_ptr->n_namesz == 0) break; sz = sizeof(Elf32_Nhdr) + ((nhdr_ptr->n_namesz + 3) & ~3) + ((nhdr_ptr->n_descsz + 3) & ~3); real_sz += sz; nhdr_ptr = (Elf32_Nhdr*)((char*)nhdr_ptr + sz); } kfree(notes_section); phdr_ptr->p_memsz = real_sz; } return 0; } /** * get_note_number_and_size_elf32 - get the number of PT_NOTE program * headers and sum of real size of their ELF note segment headers and * data. * * @ehdr_ptr: ELF header * @nr_ptnote: buffer for the number of PT_NOTE program headers * @sz_ptnote: buffer for size of unique PT_NOTE program header * * This function is used to merge multiple PT_NOTE program headers * into a unique single one. The resulting unique entry will have * @sz_ptnote in its phdr->p_mem. * * It is assumed that program headers with PT_NOTE type pointed to by * @ehdr_ptr has already been updated by update_note_header_size_elf32 * and each of PT_NOTE program headers has actual ELF note segment * size in its p_memsz member. */ static int __init get_note_number_and_size_elf32(const Elf32_Ehdr *ehdr_ptr, int *nr_ptnote, u64 *sz_ptnote) { int i; Elf32_Phdr *phdr_ptr; *nr_ptnote = *sz_ptnote = 0; phdr_ptr = (Elf32_Phdr *)(ehdr_ptr + 1); for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { if (phdr_ptr->p_type != PT_NOTE) continue; *nr_ptnote += 1; *sz_ptnote += phdr_ptr->p_memsz; } return 0; } /** * copy_notes_elf32 - copy ELF note segments in a given buffer * * @ehdr_ptr: ELF header * @notes_buf: buffer into which ELF note segments are copied * * This function is used to copy ELF note segment in the 1st kernel * into the buffer @notes_buf in the 2nd kernel. It is assumed that * size of the buffer @notes_buf is equal to or larger than sum of the * real ELF note segment headers and data. * * It is assumed that program headers with PT_NOTE type pointed to by * @ehdr_ptr has already been updated by update_note_header_size_elf32 * and each of PT_NOTE program headers has actual ELF note segment * size in its p_memsz member. */ static int __init copy_notes_elf32(const Elf32_Ehdr *ehdr_ptr, char *notes_buf) { int i, rc=0; Elf32_Phdr *phdr_ptr; phdr_ptr = (Elf32_Phdr*)(ehdr_ptr + 1); for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { u64 offset; if (phdr_ptr->p_type != PT_NOTE) continue; offset = phdr_ptr->p_offset; rc = read_from_oldmem(notes_buf, phdr_ptr->p_memsz, &offset, 0); if (rc < 0) return rc; notes_buf += phdr_ptr->p_memsz; } return 0; } /* Merges all the PT_NOTE headers into one. */ static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz, char **notes_buf, size_t *notes_sz) { int i, nr_ptnote=0, rc=0; char *tmp; Elf32_Ehdr *ehdr_ptr; Elf32_Phdr phdr; u64 phdr_sz = 0, note_off; struct vm_struct *vm; ehdr_ptr = (Elf32_Ehdr *)elfptr; rc = update_note_header_size_elf32(ehdr_ptr); if (rc < 0) return rc; rc = get_note_number_and_size_elf32(ehdr_ptr, &nr_ptnote, &phdr_sz); if (rc < 0) return rc; *notes_sz = roundup(phdr_sz, PAGE_SIZE); *notes_buf = vzalloc(*notes_sz); if (!*notes_buf) return -ENOMEM; /* * Allow users to remap ELF note segment buffer on vmalloc memory using * remap_vmalloc_range() */ vm = find_vm_area(*notes_buf); BUG_ON(!vm); vm->flags |= VM_USERMAP; rc = copy_notes_elf32(ehdr_ptr, *notes_buf); if (rc < 0) return rc; /* Prepare merged PT_NOTE program header. */ phdr.p_type = PT_NOTE; phdr.p_flags = 0; note_off = sizeof(Elf32_Ehdr) + (ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr); phdr.p_offset = roundup(note_off, PAGE_SIZE); phdr.p_vaddr = phdr.p_paddr = 0; phdr.p_filesz = phdr.p_memsz = phdr_sz; phdr.p_align = 0; /* Add merged PT_NOTE program header*/ tmp = elfptr + sizeof(Elf32_Ehdr); memcpy(tmp, &phdr, sizeof(phdr)); tmp += sizeof(phdr); /* Remove unwanted PT_NOTE program headers. */ i = (nr_ptnote - 1) * sizeof(Elf32_Phdr); *elfsz = *elfsz - i; memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf32_Ehdr)-sizeof(Elf32_Phdr))); memset(elfptr + *elfsz, 0, i); *elfsz = roundup(*elfsz, PAGE_SIZE); /* Modify e_phnum to reflect merged headers. */ ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1; return 0; } /* Add memory chunks represented by program headers to vmcore list. Also update * the new offset fields of exported program headers. */ static int __init process_ptload_program_headers_elf64(char *elfptr, size_t elfsz, size_t elfnotes_sz, struct list_head *vc_list) { int i; Elf64_Ehdr *ehdr_ptr; Elf64_Phdr *phdr_ptr; loff_t vmcore_off; struct vmcore *new; ehdr_ptr = (Elf64_Ehdr *)elfptr; phdr_ptr = (Elf64_Phdr*)(elfptr + sizeof(Elf64_Ehdr)); /* PT_NOTE hdr */ /* Skip Elf header, program headers and Elf note segment. */ vmcore_off = elfsz + elfnotes_sz; for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { u64 paddr, start, end, size; if (phdr_ptr->p_type != PT_LOAD) continue; paddr = phdr_ptr->p_offset; start = rounddown(paddr, PAGE_SIZE); end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE); size = end - start; /* Add this contiguous chunk of memory to vmcore list.*/ new = get_new_element(); if (!new) return -ENOMEM; new->paddr = start; new->size = size; list_add_tail(&new->list, vc_list); /* Update the program header offset. */ phdr_ptr->p_offset = vmcore_off + (paddr - start); vmcore_off = vmcore_off + size; } return 0; } static int __init process_ptload_program_headers_elf32(char *elfptr, size_t elfsz, size_t elfnotes_sz, struct list_head *vc_list) { int i; Elf32_Ehdr *ehdr_ptr; Elf32_Phdr *phdr_ptr; loff_t vmcore_off; struct vmcore *new; ehdr_ptr = (Elf32_Ehdr *)elfptr; phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); /* PT_NOTE hdr */ /* Skip Elf header, program headers and Elf note segment. */ vmcore_off = elfsz + elfnotes_sz; for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { u64 paddr, start, end, size; if (phdr_ptr->p_type != PT_LOAD) continue; paddr = phdr_ptr->p_offset; start = rounddown(paddr, PAGE_SIZE); end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE); size = end - start; /* Add this contiguous chunk of memory to vmcore list.*/ new = get_new_element(); if (!new) return -ENOMEM; new->paddr = start; new->size = size; list_add_tail(&new->list, vc_list); /* Update the program header offset */ phdr_ptr->p_offset = vmcore_off + (paddr - start); vmcore_off = vmcore_off + size; } return 0; } /* Sets offset fields of vmcore elements. */ static void __init set_vmcore_list_offsets(size_t elfsz, size_t elfnotes_sz, struct list_head *vc_list) { loff_t vmcore_off; struct vmcore *m; /* Skip Elf header, program headers and Elf note segment. */ vmcore_off = elfsz + elfnotes_sz; list_for_each_entry(m, vc_list, list) { m->offset = vmcore_off; vmcore_off += m->size; } } static void free_elfcorebuf(void) { free_pages((unsigned long)elfcorebuf, get_order(elfcorebuf_sz_orig)); elfcorebuf = NULL; vfree(elfnotes_buf); elfnotes_buf = NULL; } static int __init parse_crash_elf64_headers(void) { int rc=0; Elf64_Ehdr ehdr; u64 addr; addr = elfcorehdr_addr; /* Read Elf header */ rc = read_from_oldmem((char*)&ehdr, sizeof(Elf64_Ehdr), &addr, 0); if (rc < 0) return rc; /* Do some basic Verification. */ if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 || (ehdr.e_type != ET_CORE) || !vmcore_elf64_check_arch(&ehdr) || ehdr.e_ident[EI_CLASS] != ELFCLASS64 || ehdr.e_ident[EI_VERSION] != EV_CURRENT || ehdr.e_version != EV_CURRENT || ehdr.e_ehsize != sizeof(Elf64_Ehdr) || ehdr.e_phentsize != sizeof(Elf64_Phdr) || ehdr.e_phnum == 0) { pr_warn("Warning: Core image elf header is not sane\n"); return -EINVAL; } /* Read in all elf headers. */ elfcorebuf_sz_orig = sizeof(Elf64_Ehdr) + ehdr.e_phnum * sizeof(Elf64_Phdr); elfcorebuf_sz = elfcorebuf_sz_orig; elfcorebuf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, get_order(elfcorebuf_sz_orig)); if (!elfcorebuf) return -ENOMEM; addr = elfcorehdr_addr; rc = read_from_oldmem(elfcorebuf, elfcorebuf_sz_orig, &addr, 0); if (rc < 0) goto fail; /* Merge all PT_NOTE headers into one. */ rc = merge_note_headers_elf64(elfcorebuf, &elfcorebuf_sz, &elfnotes_buf, &elfnotes_sz); if (rc) goto fail; rc = process_ptload_program_headers_elf64(elfcorebuf, elfcorebuf_sz, elfnotes_sz, &vmcore_list); if (rc) goto fail; set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list); return 0; fail: free_elfcorebuf(); return rc; } static int __init parse_crash_elf32_headers(void) { int rc=0; Elf32_Ehdr ehdr; u64 addr; addr = elfcorehdr_addr; /* Read Elf header */ rc = read_from_oldmem((char*)&ehdr, sizeof(Elf32_Ehdr), &addr, 0); if (rc < 0) return rc; /* Do some basic Verification. */ if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 || (ehdr.e_type != ET_CORE) || !elf_check_arch(&ehdr) || ehdr.e_ident[EI_CLASS] != ELFCLASS32|| ehdr.e_ident[EI_VERSION] != EV_CURRENT || ehdr.e_version != EV_CURRENT || ehdr.e_ehsize != sizeof(Elf32_Ehdr) || ehdr.e_phentsize != sizeof(Elf32_Phdr) || ehdr.e_phnum == 0) { pr_warn("Warning: Core image elf header is not sane\n"); return -EINVAL; } /* Read in all elf headers. */ elfcorebuf_sz_orig = sizeof(Elf32_Ehdr) + ehdr.e_phnum * sizeof(Elf32_Phdr); elfcorebuf_sz = elfcorebuf_sz_orig; elfcorebuf = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, get_order(elfcorebuf_sz_orig)); if (!elfcorebuf) return -ENOMEM; addr = elfcorehdr_addr; rc = read_from_oldmem(elfcorebuf, elfcorebuf_sz_orig, &addr, 0); if (rc < 0) goto fail; /* Merge all PT_NOTE headers into one. */ rc = merge_note_headers_elf32(elfcorebuf, &elfcorebuf_sz, &elfnotes_buf, &elfnotes_sz); if (rc) goto fail; rc = process_ptload_program_headers_elf32(elfcorebuf, elfcorebuf_sz, elfnotes_sz, &vmcore_list); if (rc) goto fail; set_vmcore_list_offsets(elfcorebuf_sz, elfnotes_sz, &vmcore_list); return 0; fail: free_elfcorebuf(); return rc; } static int __init parse_crash_elf_headers(void) { unsigned char e_ident[EI_NIDENT]; u64 addr; int rc=0; addr = elfcorehdr_addr; rc = read_from_oldmem(e_ident, EI_NIDENT, &addr, 0); if (rc < 0) return rc; if (memcmp(e_ident, ELFMAG, SELFMAG) != 0) { pr_warn("Warning: Core image elf header not found\n"); return -EINVAL; } if (e_ident[EI_CLASS] == ELFCLASS64) { rc = parse_crash_elf64_headers(); if (rc) return rc; /* Determine vmcore size. */ vmcore_size = get_vmcore_size_elf64(elfcorebuf, elfcorebuf_sz); } else if (e_ident[EI_CLASS] == ELFCLASS32) { rc = parse_crash_elf32_headers(); if (rc) return rc; /* Determine vmcore size. */ vmcore_size = get_vmcore_size_elf32(elfcorebuf, elfcorebuf_sz); } else { pr_warn("Warning: Core image elf header is not sane\n"); return -EINVAL; } return 0; } /* Init function for vmcore module. */ static int __init vmcore_init(void) { int rc = 0; /* If elfcorehdr= has been passed in cmdline, then capture the dump.*/ if (!(is_vmcore_usable())) return rc; rc = parse_crash_elf_headers(); if (rc) { pr_warn("Kdump: vmcore not initialized\n"); return rc; } proc_vmcore = proc_create("vmcore", S_IRUSR, NULL, &proc_vmcore_operations); if (proc_vmcore) proc_vmcore->size = vmcore_size; return 0; } module_init(vmcore_init) /* Cleanup function for vmcore module. */ void vmcore_cleanup(void) { struct list_head *pos, *next; if (proc_vmcore) { proc_remove(proc_vmcore); proc_vmcore = NULL; } /* clear the vmcore list. */ list_for_each_safe(pos, next, &vmcore_list) { struct vmcore *m; m = list_entry(pos, struct vmcore, list); list_del(&m->list); kfree(m); } free_elfcorebuf(); } EXPORT_SYMBOL_GPL(vmcore_cleanup);