| /* |
| * cbfs-mkstage |
| * |
| * Copyright (C) 2008 Jordan Crouse <jordan@cosmicpenguin.net> |
| * 2009 coresystems GmbH |
| * written by Patrick Georgi <patrick.georgi@coresystems.de> |
| * Copyright (C) 2012 Google, Inc. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; version 2 of the License. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc. |
| */ |
| |
| #include <inttypes.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| #include "elfparsing.h" |
| #include "common.h" |
| #include "cbfs.h" |
| |
| /* Checks if program segment contains the ignored section */ |
| static int is_phdr_ignored(Elf64_Phdr *phdr, Elf64_Shdr *shdr) |
| { |
| /* If no ignored section, return false. */ |
| if (shdr == NULL) |
| return 0; |
| |
| Elf64_Addr sh_start = shdr->sh_addr; |
| Elf64_Addr sh_end = shdr->sh_addr + shdr->sh_size; |
| Elf64_Addr ph_start = phdr->p_vaddr; |
| Elf64_Addr ph_end = phdr->p_vaddr + phdr->p_memsz; |
| |
| /* Return true only if section occupies whole of segment. */ |
| if ((sh_start == ph_start) && (sh_end == ph_end)) { |
| DEBUG("Ignoring program segment at 0x%" PRIx64 "\n", ph_start); |
| return 1; |
| } |
| |
| /* If shdr intersects phdr at all, its a conflict */ |
| if (((sh_start >= ph_start) && (sh_start <= ph_end)) || |
| ((sh_end >= ph_start) && (sh_end <= ph_end))) { |
| ERROR("Conflicting sections in segment\n"); |
| exit(1); |
| } |
| |
| /* Program header doesn't need to be ignored. */ |
| return 0; |
| } |
| |
| /* Find section header based on ignored section name */ |
| static Elf64_Shdr *find_ignored_section_header(struct parsed_elf *pelf, |
| const char *ignore_section) |
| { |
| int i; |
| const char *shstrtab; |
| |
| /* No section needs to be ignored */ |
| if (ignore_section == NULL) |
| return NULL; |
| |
| DEBUG("Section to be ignored: %s\n", ignore_section); |
| |
| /* Get pointer to string table */ |
| shstrtab = buffer_get(pelf->strtabs[pelf->ehdr.e_shstrndx]); |
| |
| for (i = 0; i < pelf->ehdr.e_shnum; i++) { |
| Elf64_Shdr *shdr; |
| const char *section_name; |
| |
| shdr = &pelf->shdr[i]; |
| section_name = &shstrtab[shdr->sh_name]; |
| |
| /* If section name matches ignored string, return shdr */ |
| if (strcmp(section_name, ignore_section) == 0) |
| return shdr; |
| } |
| |
| /* No section matches ignore string */ |
| return NULL; |
| } |
| |
| /* returns size of result, or -1 if error. |
| * Note that, with the new code, this function |
| * works for all elf files, not just the restricted set. |
| */ |
| int parse_elf_to_stage(const struct buffer *input, struct buffer *output, |
| enum comp_algo algo, uint32_t *location, |
| const char *ignore_section) |
| { |
| struct parsed_elf pelf; |
| Elf64_Phdr *phdr; |
| Elf64_Ehdr *ehdr; |
| Elf64_Shdr *shdr_ignored; |
| char *buffer; |
| struct buffer outheader; |
| int ret = -1; |
| |
| int headers; |
| int i, outlen; |
| uint32_t data_start, data_end, mem_end; |
| |
| comp_func_ptr compress = compression_function(algo); |
| if (!compress) |
| return -1; |
| |
| DEBUG("start: parse_elf_to_stage(location=0x%x)\n", *location); |
| |
| int flags = ELF_PARSE_PHDR | ELF_PARSE_SHDR | ELF_PARSE_STRTAB; |
| |
| if (parse_elf(input, &pelf, flags)) { |
| ERROR("Couldn't parse ELF\n"); |
| return -1; |
| } |
| |
| ehdr = &pelf.ehdr; |
| phdr = &pelf.phdr[0]; |
| |
| /* Find the section header corresponding to ignored-section */ |
| shdr_ignored = find_ignored_section_header(&pelf, ignore_section); |
| |
| if (ignore_section && (shdr_ignored == NULL)) |
| WARN("Ignore section not found\n"); |
| |
| headers = ehdr->e_phnum; |
| |
| /* Ignore the program header containing ignored section */ |
| for (i = 0; i < headers; i++) { |
| if (is_phdr_ignored(&phdr[i], shdr_ignored)) |
| phdr[i].p_type = PT_NULL; |
| } |
| |
| data_start = ~0; |
| data_end = 0; |
| mem_end = 0; |
| |
| for (i = 0; i < headers; i++) { |
| unsigned int start, mend, rend; |
| |
| if (phdr[i].p_type != PT_LOAD) |
| continue; |
| |
| /* Empty segments are never interesting */ |
| if (phdr[i].p_memsz == 0) |
| continue; |
| |
| /* BSS */ |
| |
| start = phdr[i].p_paddr; |
| |
| mend = start + phdr[i].p_memsz; |
| rend = start + phdr[i].p_filesz; |
| |
| if (start < data_start) |
| data_start = start; |
| |
| if (rend > data_end) |
| data_end = rend; |
| |
| if (mend > mem_end) |
| mem_end = mend; |
| } |
| |
| if (data_start < *location) { |
| data_start = *location; |
| } |
| |
| if (data_end <= data_start) { |
| ERROR("data ends (%08lx) before it starts (%08lx). Make sure " |
| "the ELF file is correct and resides in ROM space.\n", |
| (unsigned long)data_end, (unsigned long)data_start); |
| exit(1); |
| } |
| |
| /* allocate an intermediate buffer for the data */ |
| buffer = calloc(data_end - data_start, 1); |
| |
| if (buffer == NULL) { |
| ERROR("Unable to allocate memory: %m\n"); |
| goto err; |
| } |
| |
| /* Copy the file data into the buffer */ |
| |
| for (i = 0; i < headers; i++) { |
| unsigned int l_start, l_offset = 0; |
| |
| if (phdr[i].p_type != PT_LOAD) |
| continue; |
| |
| if (phdr[i].p_memsz == 0) |
| continue; |
| |
| l_start = phdr[i].p_paddr; |
| if (l_start < *location) { |
| l_offset = *location - l_start; |
| l_start = *location; |
| } |
| |
| /* A legal ELF file can have a program header with |
| * non-zero length but zero-length file size and a |
| * non-zero offset which, added together, are > than |
| * input->size (i.e. the total file size). So we need |
| * to not even test in the case that p_filesz is zero. |
| */ |
| if (! phdr[i].p_filesz) |
| continue; |
| if (input->size < (phdr[i].p_offset + phdr[i].p_filesz)){ |
| ERROR("Underflow copying out the segment." |
| "File has %zu bytes left, segment end is %zu\n", |
| input->size, (size_t)(phdr[i].p_offset + phdr[i].p_filesz)); |
| free(buffer); |
| goto err; |
| } |
| memcpy(buffer + (l_start - data_start), |
| &input->data[phdr[i].p_offset + l_offset], |
| phdr[i].p_filesz - l_offset); |
| } |
| |
| /* Now make the output buffer */ |
| if (buffer_create(output, sizeof(struct cbfs_stage) + data_end - data_start, |
| input->name) != 0) { |
| ERROR("Unable to allocate memory: %m\n"); |
| free(buffer); |
| goto err; |
| } |
| memset(output->data, 0, output->size); |
| |
| /* Compress the data, at which point we'll know information |
| * to fill out the header. This seems backward but it works because |
| * - the output header is a known size (not always true in many xdr's) |
| * - we do need to know the compressed output size first |
| * If compression fails or makes the data bigger, we'll warn about it |
| * and use the original data. |
| */ |
| if (compress(buffer, data_end - data_start, |
| (output->data + sizeof(struct cbfs_stage)), |
| &outlen) < 0 || (unsigned)outlen > data_end - data_start) { |
| WARN("Compression failed or would make the data bigger " |
| "- disabled.\n"); |
| memcpy(output->data + sizeof(struct cbfs_stage), |
| buffer, data_end - data_start); |
| algo = CBFS_COMPRESS_NONE; |
| } |
| free(buffer); |
| |
| /* Set up for output marshaling. */ |
| outheader.data = output->data; |
| outheader.size = 0; |
| /* N.B. The original plan was that SELF data was B.E. |
| * but: this is all L.E. |
| * Maybe we should just change the spec. |
| */ |
| xdr_le.put32(&outheader, algo); |
| xdr_le.put64(&outheader, ehdr->e_entry); |
| xdr_le.put64(&outheader, data_start); |
| xdr_le.put32(&outheader, outlen); |
| xdr_le.put32(&outheader, mem_end - data_start); |
| |
| if (*location) |
| *location -= sizeof(struct cbfs_stage); |
| output->size = sizeof(struct cbfs_stage) + outlen; |
| ret = 0; |
| |
| err: |
| parsed_elf_destroy(&pelf); |
| return ret; |
| } |