Libreboot release 6 beta 1.r20140711

1 files changed, 628 insertions, 0 deletions

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;
+}