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authorFrancis Rowe <info@gluglug.org.uk>2014-07-11 04:53:00 (EDT)
committer Michał Masłowski <mtjm@mtjm.eu>2014-08-22 13:01:19 (EDT)
commitcee90ae0fce6d6aee8d78969b60c952c8890abd6 (patch)
tree6cbca259e213f5ffbc3927121e662c0377938cce /resources/cbfstool/patch
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Libreboot release 6 beta 1.
Diffstat (limited to 'resources/cbfstool/patch')
-rw-r--r--resources/cbfstool/patch/COPYING2
-rw-r--r--resources/cbfstool/patch/rmodule.c628
2 files changed, 630 insertions, 0 deletions
diff --git a/resources/cbfstool/patch/COPYING b/resources/cbfstool/patch/COPYING
new file mode 100644
index 0000000..c4c97fc
--- /dev/null
+++ b/resources/cbfstool/patch/COPYING
@@ -0,0 +1,2 @@
+rmodule.c is from and part of the coreboot project.
+Check coreboot's copyright information to see what conditions apply.
diff --git a/resources/cbfstool/patch/rmodule.c b/resources/cbfstool/patch/rmodule.c
new file mode 100644
index 0000000..989da86
--- /dev/null
+++ b/resources/cbfstool/patch/rmodule.c
@@ -0,0 +1,628 @@
+/*
+ ;* Copyright (C) 2014 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., 51 Franklin St, Fifth Floor, Boston, MA, 02110-1301 USA
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "elfparsing.h"
+#include "rmodule.h"
+#include "rmodule-defs.h"
+
+struct rmod_context;
+
+struct arch_ops {
+ int arch;
+ /* Determine if relocation is a valid type for the architecture. */
+ int (*valid_type)(struct rmod_context *ctx, Elf64_Rela *rel);
+ /* Determine if relocation should be emitted. */
+ int (*should_emit)(struct rmod_context *ctx, Elf64_Rela *rel);
+};
+
+struct rmod_context {
+ /* Ops to process relocations. */
+ struct arch_ops *ops;
+
+ /* endian conversion ops */
+ struct xdr *xdr;
+
+ /* Parsed ELF sturcture. */
+ struct parsed_elf pelf;
+ /* Program segment. */
+ Elf64_Phdr *phdr;
+
+ /* Collection of relocation addresses fixup in the module. */
+ Elf64_Xword nrelocs;
+ Elf64_Addr *emitted_relocs;
+
+ /* The following fields are addresses within the linked program. */
+ Elf64_Addr link_addr;
+ Elf64_Addr entry;
+ Elf64_Addr parameters_begin;
+ Elf64_Addr parameters_end;
+ Elf64_Addr bss_begin;
+ Elf64_Addr bss_end;
+ Elf64_Xword size;
+};
+
+/*
+ * Architecture specific support operations.
+ */
+static int valid_reloc_386(struct rmod_context *ctx, Elf64_Rela *rel)
+{
+ int type;
+
+ type = ELF64_R_TYPE(rel->r_info);
+
+ /* Only these 2 relocations are expected to be found. */
+ return (type == R_386_32 || type == R_386_PC32);
+}
+
+static int should_emit_386(struct rmod_context *ctx, Elf64_Rela *rel)
+{
+ int type;
+
+ type = ELF64_R_TYPE(rel->r_info);
+
+ /* R_386_32 relocations are absolute. Must emit these. */
+ return (type == R_386_32);
+}
+
+static struct arch_ops reloc_ops[] = {
+ {
+ .arch = EM_386,
+ .valid_type = valid_reloc_386,
+ .should_emit = should_emit_386,
+ },
+};
+
+/*
+ * Relocation processing loops.
+ */
+
+static int for_each_reloc(struct rmod_context *ctx, int do_emit)
+{
+ Elf64_Half i;
+ struct parsed_elf *pelf = &ctx->pelf;
+
+ for (i = 0; i < pelf->ehdr.e_shnum; i++) {
+ Elf64_Shdr *shdr;
+ Elf64_Rela *relocs;
+ Elf64_Xword nrelocs;
+ Elf64_Xword j;
+
+ relocs = pelf->relocs[i];
+
+ /* No relocations in this section. */
+ if (relocs == NULL)
+ continue;
+
+ shdr = &pelf->shdr[i];
+ nrelocs = shdr->sh_size / shdr->sh_entsize;
+
+ for (j = 0; j < nrelocs; j++) {
+ Elf64_Rela *r = &relocs[j];
+
+ if (!ctx->ops->valid_type(ctx, r)) {
+ ERROR("Invalid reloc type: %u\n",
+ (unsigned int)ELF64_R_TYPE(r->r_info));
+ return -1;
+ }
+
+ if (ctx->ops->should_emit(ctx, r)) {
+ int n = ctx->nrelocs;
+ if (do_emit)
+ ctx->emitted_relocs[n] = r->r_offset;
+ ctx->nrelocs++;
+ }
+ }
+ }
+
+ return 0;
+}
+
+static int find_program_segment(struct rmod_context *ctx)
+{
+ int i;
+ int nsegments;
+ struct parsed_elf *pelf;
+ Elf64_Phdr *phdr;
+
+ pelf = &ctx->pelf;
+
+ /* There should only be a single loadable segment. */
+ nsegments = 0;
+ for (i = 0; i < pelf->ehdr.e_phnum; i++) {
+ if (pelf->phdr[i].p_type != PT_LOAD)
+ continue;
+ phdr = &pelf->phdr[i];
+ nsegments++;
+ }
+
+ if (nsegments != 1) {
+ ERROR("Unexepcted number of loadable segments: %d.\n",
+ nsegments);
+ return -1;
+ }
+
+ INFO("Segment at 0x%0llx, file size 0x%0llx, mem size 0x%0llx.\n",
+ (long long)phdr->p_vaddr, (long long)phdr->p_filesz,
+ (long long)phdr->p_memsz);
+
+ ctx->phdr = phdr;
+
+ return 0;
+}
+
+static int
+filter_relocation_sections(struct rmod_context *ctx)
+{
+ int i;
+ const char *shstrtab;
+ struct parsed_elf *pelf;
+ const Elf64_Phdr *phdr;
+
+ pelf = &ctx->pelf;
+ phdr = ctx->phdr;
+ shstrtab = buffer_get(pelf->strtabs[pelf->ehdr.e_shstrndx]);
+
+ /*
+ * Find all relocation sections that contain relocation entries
+ * for sections that fall within the bounds of the segment. For
+ * easier processing the pointer to the relocation array for the
+ * sections that don't fall within the loadable program are NULL'd
+ * out.
+ */
+ for (i = 0; i < pelf->ehdr.e_shnum; i++) {
+ Elf64_Shdr *shdr;
+ Elf64_Word sh_info;
+ const char *section_name;
+
+ shdr = &pelf->shdr[i];
+
+ /* Ignore non-relocation sections. */
+ if (shdr->sh_type != SHT_RELA && shdr->sh_type != SHT_REL)
+ continue;
+
+ /* Obtain section which relocations apply. */
+ sh_info = shdr->sh_info;
+ shdr = &pelf->shdr[sh_info];
+
+ section_name = &shstrtab[shdr->sh_name];
+ DEBUG("Relocation section found for '%s' section.\n",
+ section_name);
+
+ /* Do not process relocations for debug sections. */
+ if (strstr(section_name, ".debug") != NULL) {
+ pelf->relocs[i] = NULL;
+ continue;
+ }
+
+ /*
+ * If relocations apply to a non program section ignore the
+ * relocations for future processing.
+ */
+ if (shdr->sh_type != SHT_PROGBITS) {
+ pelf->relocs[i] = NULL;
+ continue;
+ }
+
+ if (shdr->sh_addr < phdr->p_vaddr ||
+ ((shdr->sh_addr + shdr->sh_size) >
+ (phdr->p_vaddr + phdr->p_memsz))) {
+ ERROR("Relocations being applied to section %d not "
+ "within segment region.\n", sh_info);
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+static int vaddr_cmp(const void *a, const void *b)
+{
+ const Elf64_Addr *pa = a;
+ const Elf64_Addr *pb = b;
+
+ if (*pa < *pb)
+ return -1;
+ if (*pa > *pb)
+ return 1;
+ return 0;
+}
+
+static int collect_relocations(struct rmod_context *ctx)
+{
+ int nrelocs;
+
+ /*
+ * The relocs array in the pelf should only contain relocations that
+ * apply to the program. Count the number relocations. Then collect
+ * them into the allocated buffer.
+ */
+ if (for_each_reloc(ctx, 0))
+ return -1;
+
+ nrelocs = ctx->nrelocs;
+ INFO("%d relocations to be emitted.\n", nrelocs);
+ if (!nrelocs) {
+ ERROR("No valid relocations in file.\n");
+ return -1;
+ }
+
+ /* Reset the counter for indexing into the array. */
+ ctx->nrelocs = 0;
+ ctx->emitted_relocs = calloc(nrelocs, sizeof(Elf64_Addr));
+ /* Write out the relocations into the emitted_relocs array. */
+ if (for_each_reloc(ctx, 1))
+ return -1;
+
+ if (ctx->nrelocs != nrelocs) {
+ ERROR("Mismatch counted and emitted relocations: %zu vs %zu.\n",
+ (size_t)nrelocs, (size_t)ctx->nrelocs);
+ return -1;
+ }
+
+ /* Sort the relocations by their address. */
+ qsort(ctx->emitted_relocs, nrelocs, sizeof(Elf64_Addr), vaddr_cmp);
+
+ return 0;
+}
+
+static int
+populate_sym(struct rmod_context *ctx, const char *sym_name, Elf64_Addr *addr,
+ int nsyms, const char *strtab)
+{
+ int i;
+ Elf64_Sym *syms;
+
+ syms = ctx->pelf.syms;
+
+ for (i = 0; i < nsyms; i++) {
+ if (syms[i].st_name == 0)
+ continue;
+ if (strcmp(sym_name, &strtab[syms[i].st_name]))
+ continue;
+ DEBUG("%s -> 0x%llx\n", sym_name, (long long)syms[i].st_value);
+ *addr = syms[i].st_value;
+ return 0;
+ }
+ ERROR("symbol '%s' not found.\n", sym_name);
+ return -1;
+}
+
+static int populate_program_info(struct rmod_context *ctx)
+{
+ int i;
+ const char *strtab;
+ struct parsed_elf *pelf;
+ Elf64_Ehdr *ehdr;
+ int nsyms;
+
+ pelf = &ctx->pelf;
+ ehdr = &pelf->ehdr;
+
+ /* Obtain the string table. */
+ strtab = NULL;
+ for (i = 0; i < ehdr->e_shnum; i++) {
+ if (ctx->pelf.strtabs[i] == NULL)
+ continue;
+ /* Don't use the section headers' string table. */
+ if (i == ehdr->e_shstrndx)
+ continue;
+ strtab = buffer_get(ctx->pelf.strtabs[i]);
+ break;
+ }
+
+ if (strtab == NULL) {
+ ERROR("No string table found.\n");
+ return -1;
+ }
+
+ /* Determine number of symbols. */
+ nsyms = 0;
+ for (i = 0; i < ehdr->e_shnum; i++) {
+ if (pelf->shdr[i].sh_type != SHT_SYMTAB)
+ continue;
+
+ nsyms = pelf->shdr[i].sh_size / pelf->shdr[i].sh_entsize;
+ break;
+ }
+
+ if (populate_sym(ctx, "_module_params_begin", &ctx->parameters_begin,
+ nsyms, strtab))
+ return -1;
+
+ if (populate_sym(ctx, "_module_params_end", &ctx->parameters_end,
+ nsyms, strtab))
+ return -1;
+
+ if (populate_sym(ctx, "_bss", &ctx->bss_begin, nsyms, strtab))
+ return -1;
+
+ if (populate_sym(ctx, "_ebss", &ctx->bss_end, nsyms, strtab))
+ return -1;
+
+ if (populate_sym(ctx, "__rmodule_entry", &ctx->entry, nsyms, strtab))
+ return -1;
+
+ /* Link address is the virtual address of the program segment. */
+ ctx->link_addr = ctx->phdr->p_vaddr;
+
+ /* The program size is the memsz of the program segment. */
+ ctx->size = ctx->phdr->p_memsz;
+
+ return 0;
+}
+
+static int
+add_section(struct elf_writer *ew, struct buffer *data, const char *name,
+ Elf64_Addr addr, Elf64_Word size)
+{
+ Elf64_Shdr shdr;
+ int ret;
+
+ memset(&shdr, 0, sizeof(shdr));
+ if (data != NULL) {
+ shdr.sh_type = SHT_PROGBITS;
+ shdr.sh_flags = SHF_ALLOC | SHF_WRITE | SHF_EXECINSTR;
+ } else {
+ shdr.sh_type = SHT_NOBITS;
+ shdr.sh_flags = SHF_ALLOC;
+ }
+ shdr.sh_addr = addr;
+ shdr.sh_offset = addr;
+ shdr.sh_size = size;
+
+ ret = elf_writer_add_section(ew, &shdr, data, name);
+
+ if (ret)
+ ERROR("Could not add '%s' section.\n", name);
+
+ return ret;
+}
+
+static int
+write_elf(const struct rmod_context *ctx, const struct buffer *in,
+ struct buffer *out)
+{
+ int i;
+ int ret;
+ int bit64;
+ size_t loc;
+ size_t rmod_data_size;
+ struct elf_writer *ew;
+ struct buffer rmod_data;
+ struct buffer rmod_header;
+ struct buffer program;
+ struct buffer relocs;
+ Elf64_Xword total_size;
+ Elf64_Addr addr;
+ Elf64_Ehdr ehdr;
+
+ bit64 = ctx->pelf.ehdr.e_ident[EI_CLASS] == ELFCLASS64;
+
+ /*
+ * 3 sections will be added to the ELF file.
+ * +------------------+
+ * | rmodule header |
+ * +------------------+
+ * | program |
+ * +------------------+
+ * | relocations |
+ * +------------------+
+ */
+
+ /* Create buffer for header and relocations. */
+ rmod_data_size = sizeof(struct rmodule_header);
+ if (bit64)
+ rmod_data_size += ctx->nrelocs * sizeof(Elf64_Addr);
+ else
+ rmod_data_size += ctx->nrelocs * sizeof(Elf32_Addr);
+
+ if (buffer_create(&rmod_data, rmod_data_size, "rmod"))
+ return -1;
+
+ buffer_splice(&rmod_header, &rmod_data,
+ 0, sizeof(struct rmodule_header));
+ buffer_clone(&relocs, &rmod_data);
+ buffer_seek(&relocs, sizeof(struct rmodule_header));
+
+ /* Reset current location. */
+ buffer_set_size(&rmod_header, 0);
+ buffer_set_size(&relocs, 0);
+
+ /* Program contents. */
+ buffer_splice(&program, in, ctx->phdr->p_offset, ctx->phdr->p_filesz);
+
+ /* Create ELF writer with modified entry point. */
+ memcpy(&ehdr, &ctx->pelf.ehdr, sizeof(ehdr));
+ ehdr.e_entry = ctx->entry;
+ ew = elf_writer_init(&ehdr);
+
+ if (ew == NULL) {
+ ERROR("Failed to create ELF writer.\n");
+ buffer_delete(&rmod_data);
+ return -1;
+ }
+
+ /* Write out rmodule_header. */
+ ctx->xdr->put16(&rmod_header, RMODULE_MAGIC);
+ ctx->xdr->put8(&rmod_header, RMODULE_VERSION_1);
+ ctx->xdr->put8(&rmod_header, 0);
+ /* payload_begin_offset */
+ loc = sizeof(struct rmodule_header);
+ ctx->xdr->put32(&rmod_header, loc);
+ /* payload_end_offset */
+ loc += ctx->phdr->p_filesz;
+ ctx->xdr->put32(&rmod_header, loc);
+ /* relocations_begin_offset */
+ ctx->xdr->put32(&rmod_header, loc);
+ /* relocations_end_offset */
+ if (bit64)
+ loc += ctx->nrelocs * sizeof(Elf64_Addr);
+ else
+ loc += ctx->nrelocs * sizeof(Elf32_Addr);
+ ctx->xdr->put32(&rmod_header, loc);
+ /* module_link_start_address */
+ ctx->xdr->put32(&rmod_header, ctx->link_addr);
+ /* module_program_size */
+ ctx->xdr->put32(&rmod_header, ctx->size);
+ /* module_entry_point */
+ ctx->xdr->put32(&rmod_header, ctx->entry);
+ /* parameters_begin */
+ ctx->xdr->put32(&rmod_header, ctx->parameters_begin);
+ /* parameters_end */
+ ctx->xdr->put32(&rmod_header, ctx->parameters_end);
+ /* bss_begin */
+ ctx->xdr->put32(&rmod_header, ctx->bss_begin);
+ /* bss_end */
+ ctx->xdr->put32(&rmod_header, ctx->bss_end);
+ /* padding[4] */
+ ctx->xdr->put32(&rmod_header, 0);
+ ctx->xdr->put32(&rmod_header, 0);
+ ctx->xdr->put32(&rmod_header, 0);
+ ctx->xdr->put32(&rmod_header, 0);
+
+ /* Write the relocations. */
+ for (i = 0; i < ctx->nrelocs; i++) {
+ if (bit64)
+ ctx->xdr->put64(&relocs, ctx->emitted_relocs[i]);
+ else
+ ctx->xdr->put32(&relocs, ctx->emitted_relocs[i]);
+ }
+
+ total_size = 0;
+ addr = 0;
+
+ /*
+ * There are 2 cases to deal with. The program has a large NOBITS
+ * section and the relocations can fit entirely within occupied memory
+ * region for the program. The other is that the relocations increase
+ * the memory footprint of the program if it was loaded directly into
+ * the region it would run. The rmdoule header is a fixed cost that
+ * is considered a part of the program.
+ */
+ total_size += buffer_size(&rmod_header);
+ total_size += ctx->phdr->p_memsz;
+ if (buffer_size(&relocs) + ctx->phdr->p_filesz > total_size) {
+ total_size -= ctx->phdr->p_memsz;
+ total_size += buffer_size(&relocs);
+ total_size += ctx->phdr->p_filesz;
+ }
+
+ ret = add_section(ew, &rmod_header, ".header", addr,
+ buffer_size(&rmod_header));
+ if (ret < 0)
+ goto out;
+ addr += buffer_size(&rmod_header);
+
+ ret = add_section(ew, &program, ".program", addr, ctx->phdr->p_filesz);
+ if (ret < 0)
+ goto out;
+ addr += ctx->phdr->p_filesz;
+
+ ret = add_section(ew, &relocs, ".relocs", addr, buffer_size(&relocs));
+ if (ret < 0)
+ goto out;
+ addr += buffer_size(&relocs);
+
+ if (total_size != addr) {
+ ret = add_section(ew, NULL, ".empty", addr, total_size - addr);
+ if (ret < 0)
+ goto out;
+ }
+
+ /*
+ * Ensure last section has a memory usage that meets the required
+ * total size of the program in memory.
+ */
+
+ ret = elf_writer_serialize(ew, out);
+ if (ret < 0)
+ ERROR("Failed to serialize ELF to buffer.\n");
+
+out:
+ buffer_delete(&rmod_data);
+ elf_writer_destroy(ew);
+
+ return ret;
+}
+
+int rmodule_create(const struct buffer *elfin, struct buffer *elfout)
+{
+ struct rmod_context ctx;
+ struct parsed_elf *pelf;
+ int i;
+ int ret;
+
+ ret = -1;
+ memset(&ctx, 0, sizeof(ctx));
+ pelf = &ctx.pelf;
+
+ if (parse_elf(elfin, pelf, ELF_PARSE_ALL)) {
+ ERROR("Couldn't parse ELF!\n");
+ return -1;
+ }
+
+ /* Only allow executables to be turned into rmodules. */
+ if (pelf->ehdr.e_type != ET_EXEC) {
+ ERROR("ELF is not an executable: %u.\n", pelf->ehdr.e_type);
+ goto out;
+ }
+
+ /* Determine if architecture is supported. */
+ for (i = 0; i < ARRAY_SIZE(reloc_ops); i++) {
+ if (reloc_ops[i].arch == pelf->ehdr.e_machine) {
+ ctx.ops = &reloc_ops[i];
+ break;
+ }
+ }
+
+ if (ctx.ops == NULL) {
+ ERROR("ELF is unsupported arch: %u.\n", pelf->ehdr.e_machine);
+ goto out;
+ }
+
+ /* Set the endian ops. */
+ if (ctx.pelf.ehdr.e_ident[EI_DATA] == ELFDATA2MSB)
+ ctx.xdr = &xdr_be;
+ else
+ ctx.xdr = &xdr_le;
+
+ if (find_program_segment(&ctx))
+ goto out;
+
+ if (filter_relocation_sections(&ctx))
+ goto out;
+
+ if (collect_relocations(&ctx))
+ goto out;
+
+ if (populate_program_info(&ctx))
+ goto out;
+
+ if (write_elf(&ctx, elfin, elfout))
+ goto out;
+
+ ret = 0;
+
+out:
+ free(ctx.emitted_relocs);
+ parsed_elf_destroy(pelf);
+ return ret;
+}