[PATCH] kdump: Parse elf32 headers and export through /proc/vmcore
o Adds support for parsing core ELF32 headers. o I am expecting ELF32 support to go away down the line. This patch has been introduced for testing purposes as gdb can not parse ELF64 headers for i386. When a decent user space solution is available, ELF32 support can go away. Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Vivek Goyal
Linus Torvalds
parent
666bfddbe8
commit
72658e9d50
1 changed files with 218 additions and 0 deletions
218
fs/proc/vmcore.c
218
fs/proc/vmcore.c
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@ -202,6 +202,23 @@ static u64 __init get_vmcore_size_elf64(char *elfptr)
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return size;
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}
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static u64 __init get_vmcore_size_elf32(char *elfptr)
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{
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int i;
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u64 size;
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Elf32_Ehdr *ehdr_ptr;
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Elf32_Phdr *phdr_ptr;
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ehdr_ptr = (Elf32_Ehdr *)elfptr;
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phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr));
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size = sizeof(Elf32_Ehdr) + ((ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr));
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for (i = 0; i < ehdr_ptr->e_phnum; i++) {
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size += phdr_ptr->p_memsz;
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phdr_ptr++;
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}
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return size;
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}
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/* Merges all the PT_NOTE headers into one. */
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static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
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struct list_head *vc_list)
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@ -283,6 +300,87 @@ static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
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return 0;
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}
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/* Merges all the PT_NOTE headers into one. */
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static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
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struct list_head *vc_list)
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{
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int i, nr_ptnote=0, rc=0;
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char *tmp;
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Elf32_Ehdr *ehdr_ptr;
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Elf32_Phdr phdr, *phdr_ptr;
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Elf32_Nhdr *nhdr_ptr;
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u64 phdr_sz = 0, note_off;
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ehdr_ptr = (Elf32_Ehdr *)elfptr;
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phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr));
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for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
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int j;
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void *notes_section;
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struct vmcore *new;
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u64 offset, max_sz, sz, real_sz = 0;
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if (phdr_ptr->p_type != PT_NOTE)
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continue;
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nr_ptnote++;
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max_sz = phdr_ptr->p_memsz;
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offset = phdr_ptr->p_offset;
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notes_section = kmalloc(max_sz, GFP_KERNEL);
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if (!notes_section)
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return -ENOMEM;
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rc = read_from_oldmem(notes_section, max_sz, &offset, 0);
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if (rc < 0) {
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kfree(notes_section);
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return rc;
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}
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nhdr_ptr = notes_section;
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for (j = 0; j < max_sz; j += sz) {
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if (nhdr_ptr->n_namesz == 0)
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break;
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sz = sizeof(Elf32_Nhdr) +
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((nhdr_ptr->n_namesz + 3) & ~3) +
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((nhdr_ptr->n_descsz + 3) & ~3);
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real_sz += sz;
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nhdr_ptr = (Elf32_Nhdr*)((char*)nhdr_ptr + sz);
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}
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/* Add this contiguous chunk of notes section to vmcore list.*/
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new = get_new_element();
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if (!new) {
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kfree(notes_section);
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return -ENOMEM;
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}
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new->paddr = phdr_ptr->p_offset;
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new->size = real_sz;
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list_add_tail(&new->list, vc_list);
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phdr_sz += real_sz;
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kfree(notes_section);
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}
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/* Prepare merged PT_NOTE program header. */
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phdr.p_type = PT_NOTE;
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phdr.p_flags = 0;
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note_off = sizeof(Elf32_Ehdr) +
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(ehdr_ptr->e_phnum - nr_ptnote +1) * sizeof(Elf32_Phdr);
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phdr.p_offset = note_off;
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phdr.p_vaddr = phdr.p_paddr = 0;
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phdr.p_filesz = phdr.p_memsz = phdr_sz;
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phdr.p_align = 0;
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/* Add merged PT_NOTE program header*/
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tmp = elfptr + sizeof(Elf32_Ehdr);
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memcpy(tmp, &phdr, sizeof(phdr));
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tmp += sizeof(phdr);
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/* Remove unwanted PT_NOTE program headers. */
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i = (nr_ptnote - 1) * sizeof(Elf32_Phdr);
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*elfsz = *elfsz - i;
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memmove(tmp, tmp+i, ((*elfsz)-sizeof(Elf32_Ehdr)-sizeof(Elf32_Phdr)));
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/* Modify e_phnum to reflect merged headers. */
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ehdr_ptr->e_phnum = ehdr_ptr->e_phnum - nr_ptnote + 1;
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return 0;
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}
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/* Add memory chunks represented by program headers to vmcore list. Also update
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* the new offset fields of exported program headers. */
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static int __init process_ptload_program_headers_elf64(char *elfptr,
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@ -322,6 +420,43 @@ static int __init process_ptload_program_headers_elf64(char *elfptr,
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return 0;
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}
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static int __init process_ptload_program_headers_elf32(char *elfptr,
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size_t elfsz,
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struct list_head *vc_list)
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{
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int i;
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Elf32_Ehdr *ehdr_ptr;
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Elf32_Phdr *phdr_ptr;
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loff_t vmcore_off;
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struct vmcore *new;
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ehdr_ptr = (Elf32_Ehdr *)elfptr;
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phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); /* PT_NOTE hdr */
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/* First program header is PT_NOTE header. */
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vmcore_off = sizeof(Elf32_Ehdr) +
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(ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr) +
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phdr_ptr->p_memsz; /* Note sections */
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for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) {
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if (phdr_ptr->p_type != PT_LOAD)
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continue;
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/* Add this contiguous chunk of memory to vmcore list.*/
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new = get_new_element();
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if (!new)
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return -ENOMEM;
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new->paddr = phdr_ptr->p_offset;
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new->size = phdr_ptr->p_memsz;
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list_add_tail(&new->list, vc_list);
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/* Update the program header offset */
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phdr_ptr->p_offset = vmcore_off;
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vmcore_off = vmcore_off + phdr_ptr->p_memsz;
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}
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return 0;
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}
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/* Sets offset fields of vmcore elements. */
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static void __init set_vmcore_list_offsets_elf64(char *elfptr,
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struct list_head *vc_list)
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@ -342,6 +477,26 @@ static void __init set_vmcore_list_offsets_elf64(char *elfptr,
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}
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}
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/* Sets offset fields of vmcore elements. */
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static void __init set_vmcore_list_offsets_elf32(char *elfptr,
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struct list_head *vc_list)
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{
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loff_t vmcore_off;
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Elf32_Ehdr *ehdr_ptr;
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struct vmcore *m;
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ehdr_ptr = (Elf32_Ehdr *)elfptr;
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/* Skip Elf header and program headers. */
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vmcore_off = sizeof(Elf32_Ehdr) +
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(ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr);
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list_for_each_entry(m, vc_list, list) {
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m->offset = vmcore_off;
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vmcore_off += m->size;
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}
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}
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static int __init parse_crash_elf64_headers(void)
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{
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int rc=0;
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@ -398,6 +553,62 @@ static int __init parse_crash_elf64_headers(void)
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return 0;
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}
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static int __init parse_crash_elf32_headers(void)
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{
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int rc=0;
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Elf32_Ehdr ehdr;
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u64 addr;
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addr = elfcorehdr_addr;
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/* Read Elf header */
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rc = read_from_oldmem((char*)&ehdr, sizeof(Elf32_Ehdr), &addr, 0);
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if (rc < 0)
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return rc;
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/* Do some basic Verification. */
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if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
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(ehdr.e_type != ET_CORE) ||
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!elf_check_arch(&ehdr) ||
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ehdr.e_ident[EI_CLASS] != ELFCLASS32||
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ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
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ehdr.e_version != EV_CURRENT ||
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ehdr.e_ehsize != sizeof(Elf32_Ehdr) ||
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ehdr.e_phentsize != sizeof(Elf32_Phdr) ||
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ehdr.e_phnum == 0) {
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printk(KERN_WARNING "Warning: Core image elf header is not"
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"sane\n");
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return -EINVAL;
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}
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/* Read in all elf headers. */
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elfcorebuf_sz = sizeof(Elf32_Ehdr) + ehdr.e_phnum * sizeof(Elf32_Phdr);
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elfcorebuf = kmalloc(elfcorebuf_sz, GFP_KERNEL);
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if (!elfcorebuf)
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return -ENOMEM;
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addr = elfcorehdr_addr;
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rc = read_from_oldmem(elfcorebuf, elfcorebuf_sz, &addr, 0);
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if (rc < 0) {
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kfree(elfcorebuf);
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return rc;
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}
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/* Merge all PT_NOTE headers into one. */
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rc = merge_note_headers_elf32(elfcorebuf, &elfcorebuf_sz, &vmcore_list);
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if (rc) {
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kfree(elfcorebuf);
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return rc;
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}
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rc = process_ptload_program_headers_elf32(elfcorebuf, elfcorebuf_sz,
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&vmcore_list);
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if (rc) {
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kfree(elfcorebuf);
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return rc;
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}
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set_vmcore_list_offsets_elf32(elfcorebuf, &vmcore_list);
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return 0;
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}
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static int __init parse_crash_elf_headers(void)
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{
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unsigned char e_ident[EI_NIDENT];
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@ -421,6 +632,13 @@ static int __init parse_crash_elf_headers(void)
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/* Determine vmcore size. */
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vmcore_size = get_vmcore_size_elf64(elfcorebuf);
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} else if (e_ident[EI_CLASS] == ELFCLASS32) {
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rc = parse_crash_elf32_headers();
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if (rc)
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return rc;
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/* Determine vmcore size. */
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vmcore_size = get_vmcore_size_elf32(elfcorebuf);
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} else {
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printk(KERN_WARNING "Warning: Core image elf header is not"
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" sane\n");
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