From 72658e9d5004fc0dd807bea9eda49e6a52e40103 Mon Sep 17 00:00:00 2001 From: Vivek Goyal Date: Sat, 25 Jun 2005 14:58:22 -0700 Subject: [PATCH] [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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/vmcore.c | 218 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 218 insertions(+) diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index 8ad46785584..3b2e7b69e63 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -202,6 +202,23 @@ static u64 __init get_vmcore_size_elf64(char *elfptr) return size; } +static u64 __init get_vmcore_size_elf32(char *elfptr) +{ + 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 = sizeof(Elf32_Ehdr) + ((ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr)); + for (i = 0; i < ehdr_ptr->e_phnum; i++) { + size += phdr_ptr->p_memsz; + phdr_ptr++; + } + return size; +} + /* Merges all the PT_NOTE headers into one. */ static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz, struct list_head *vc_list) @@ -283,6 +300,87 @@ static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz, return 0; } +/* Merges all the PT_NOTE headers into one. */ +static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz, + struct list_head *vc_list) +{ + int i, nr_ptnote=0, rc=0; + char *tmp; + Elf32_Ehdr *ehdr_ptr; + Elf32_Phdr phdr, *phdr_ptr; + Elf32_Nhdr *nhdr_ptr; + u64 phdr_sz = 0, note_off; + + ehdr_ptr = (Elf32_Ehdr *)elfptr; + phdr_ptr = (Elf32_Phdr*)(elfptr + sizeof(Elf32_Ehdr)); + for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { + int j; + void *notes_section; + struct vmcore *new; + u64 offset, max_sz, sz, real_sz = 0; + if (phdr_ptr->p_type != PT_NOTE) + continue; + nr_ptnote++; + 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; + for (j = 0; j < max_sz; j += 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); + } + + /* Add this contiguous chunk of notes section to vmcore list.*/ + new = get_new_element(); + if (!new) { + kfree(notes_section); + return -ENOMEM; + } + new->paddr = phdr_ptr->p_offset; + new->size = real_sz; + list_add_tail(&new->list, vc_list); + phdr_sz += real_sz; + kfree(notes_section); + } + + /* 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 = note_off; + 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))); + + /* 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, @@ -322,6 +420,43 @@ static int __init process_ptload_program_headers_elf64(char *elfptr, return 0; } +static int __init process_ptload_program_headers_elf32(char *elfptr, + size_t elfsz, + 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 */ + + /* First program header is PT_NOTE header. */ + vmcore_off = sizeof(Elf32_Ehdr) + + (ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr) + + phdr_ptr->p_memsz; /* Note sections */ + + for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { + if (phdr_ptr->p_type != PT_LOAD) + continue; + + /* Add this contiguous chunk of memory to vmcore list.*/ + new = get_new_element(); + if (!new) + return -ENOMEM; + new->paddr = phdr_ptr->p_offset; + new->size = phdr_ptr->p_memsz; + list_add_tail(&new->list, vc_list); + + /* Update the program header offset */ + phdr_ptr->p_offset = vmcore_off; + vmcore_off = vmcore_off + phdr_ptr->p_memsz; + } + return 0; +} + /* Sets offset fields of vmcore elements. */ static void __init set_vmcore_list_offsets_elf64(char *elfptr, struct list_head *vc_list) @@ -342,6 +477,26 @@ static void __init set_vmcore_list_offsets_elf64(char *elfptr, } } +/* Sets offset fields of vmcore elements. */ +static void __init set_vmcore_list_offsets_elf32(char *elfptr, + struct list_head *vc_list) +{ + loff_t vmcore_off; + Elf32_Ehdr *ehdr_ptr; + struct vmcore *m; + + ehdr_ptr = (Elf32_Ehdr *)elfptr; + + /* Skip Elf header and program headers. */ + vmcore_off = sizeof(Elf32_Ehdr) + + (ehdr_ptr->e_phnum) * sizeof(Elf32_Phdr); + + list_for_each_entry(m, vc_list, list) { + m->offset = vmcore_off; + vmcore_off += m->size; + } +} + static int __init parse_crash_elf64_headers(void) { int rc=0; @@ -398,6 +553,62 @@ static int __init parse_crash_elf64_headers(void) return 0; } +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) { + printk(KERN_WARNING "Warning: Core image elf header is not" + "sane\n"); + return -EINVAL; + } + + /* Read in all elf headers. */ + elfcorebuf_sz = sizeof(Elf32_Ehdr) + ehdr.e_phnum * sizeof(Elf32_Phdr); + elfcorebuf = kmalloc(elfcorebuf_sz, GFP_KERNEL); + if (!elfcorebuf) + return -ENOMEM; + addr = elfcorehdr_addr; + rc = read_from_oldmem(elfcorebuf, elfcorebuf_sz, &addr, 0); + if (rc < 0) { + kfree(elfcorebuf); + return rc; + } + + /* Merge all PT_NOTE headers into one. */ + rc = merge_note_headers_elf32(elfcorebuf, &elfcorebuf_sz, &vmcore_list); + if (rc) { + kfree(elfcorebuf); + return rc; + } + rc = process_ptload_program_headers_elf32(elfcorebuf, elfcorebuf_sz, + &vmcore_list); + if (rc) { + kfree(elfcorebuf); + return rc; + } + set_vmcore_list_offsets_elf32(elfcorebuf, &vmcore_list); + return 0; +} + static int __init parse_crash_elf_headers(void) { unsigned char e_ident[EI_NIDENT]; @@ -421,6 +632,13 @@ static int __init parse_crash_elf_headers(void) /* Determine vmcore size. */ vmcore_size = get_vmcore_size_elf64(elfcorebuf); + } 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); } else { printk(KERN_WARNING "Warning: Core image elf header is not" " sane\n"); -- 2.20.1