1 files changed, 748 insertions, 0 deletions

diff --git a/lib/libdwarf/dwarf_init.c b/lib/libdwarf/dwarf_init.c
new file mode 100644
index 0000000..30b7b0f
--- /dev/null
+++ b/lib/libdwarf/dwarf_init.c
@@ -0,0 +1,748 @@
+/*-
+ * Copyright (c) 2007 John Birrell (jb@freebsd.org)
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include "_libdwarf.h"
+
+static const char *debug_snames[DWARF_DEBUG_SNAMES] = {
+	".debug_abbrev",
+	".debug_aranges",
+	".debug_frame",
+	".debug_info",
+	".debug_line",
+	".debug_pubnames",
+	".eh_frame",
+	".debug_macinfo",
+	".debug_str",
+	".debug_loc",
+	".debug_pubtypes",
+	".debug_ranges",
+	".debug_static_func",
+	".debug_static_vars",
+	".debug_types",
+	".debug_weaknames",
+	".symtab",
+	".strtab"
+};
+
+static uint64_t (*dwarf_read) (Elf_Data **, uint64_t *, int);
+static void (*dwarf_write) (Elf_Data **, uint64_t *, uint64_t, int);
+
+static uint64_t
+dwarf_read_lsb(Elf_Data **dp, uint64_t *offsetp, int bytes_to_read)
+{
+	uint64_t ret = 0;
+
+	uint8_t *src = (uint8_t *) (*dp)->d_buf + *offsetp;
+
+	switch (bytes_to_read) {
+	case 8:
+		ret |= ((uint64_t) src[4]) << 32 | ((uint64_t) src[5]) << 40;
+		ret |= ((uint64_t) src[6]) << 48 | ((uint64_t) src[7]) << 56;
+	case 4:
+		ret |= ((uint64_t) src[2]) << 16 | ((uint64_t) src[3]) << 24;
+	case 2:
+		ret |= ((uint64_t) src[1]) << 8;
+	case 1:
+		ret |= src[0];
+		break;
+	default:
+		return 0;
+		break;
+	}
+
+	*offsetp += bytes_to_read;
+
+	return ret;
+}
+
+static uint64_t
+dwarf_read_msb(Elf_Data **dp, uint64_t *offsetp, int bytes_to_read)
+{
+	uint64_t ret = 0;
+
+	uint8_t *src = (uint8_t *) (*dp)->d_buf + *offsetp;
+
+	switch (bytes_to_read) {
+	case 1:
+		ret = src[0];
+		break;
+	case 2:
+		ret = src[1] | ((uint64_t) src[0]) << 8;
+		break;
+	case 4:
+		ret = src[3] | ((uint64_t) src[2]) << 8;
+		ret |= ((uint64_t) src[1]) << 16 | ((uint64_t) src[0]) << 24;
+		break;
+	case 8:
+		ret = src[7] | ((uint64_t) src[6]) << 8;
+		ret |= ((uint64_t) src[5]) << 16 | ((uint64_t) src[4]) << 24;
+		ret |= ((uint64_t) src[3]) << 32 | ((uint64_t) src[2]) << 40;
+		ret |= ((uint64_t) src[1]) << 48 | ((uint64_t) src[0]) << 56;
+		break;
+	default:
+		return 0;
+		break;
+	}
+
+	*offsetp += bytes_to_read;
+
+	return ret;
+}
+
+static void
+dwarf_write_lsb(Elf_Data **dp, uint64_t *offsetp, uint64_t value, int bytes_to_write)
+{
+	uint8_t *dst = (uint8_t *) (*dp)->d_buf + *offsetp;
+
+	switch (bytes_to_write) {
+	case 8:
+		dst[7] = (value >> 56) & 0xff;
+		dst[6] = (value >> 48) & 0xff;
+		dst[5] = (value >> 40) & 0xff;
+		dst[4] = (value >> 32) & 0xff;
+	case 4:
+		dst[3] = (value >> 24) & 0xff;
+		dst[2] = (value >> 16) & 0xff;
+	case 2:
+		dst[1] = (value >> 8) & 0xff;
+	case 1:
+		dst[0] = value & 0xff;
+		break;
+	default:
+		return;
+		break;
+	}
+
+	*offsetp += bytes_to_write;
+}
+
+static void
+dwarf_write_msb(Elf_Data **dp, uint64_t *offsetp, uint64_t value, int bytes_to_write)
+{
+	uint8_t *dst = (uint8_t *) (*dp)->d_buf + *offsetp;
+
+	switch (bytes_to_write) {
+	case 8:
+		dst[7] = value & 0xff;
+		dst[6] = (value >> 8) & 0xff;
+		dst[5] = (value >> 16) & 0xff;
+		dst[4] = (value >> 24) & 0xff;
+		value >>= 32;
+	case 4:
+		dst[3] = value & 0xff;
+		dst[2] = (value >> 8) & 0xff;
+		value >>= 16;
+	case 2:
+		dst[1] = value & 0xff;
+		value >>= 8;
+	case 1:
+		dst[0] = value & 0xff;
+		break;
+	default:
+		return;
+		break;
+	}
+
+	*offsetp += bytes_to_write;
+}
+
+static int64_t
+dwarf_read_sleb128(Elf_Data **dp, uint64_t *offsetp)
+{
+	int64_t ret = 0;
+	uint8_t b;
+	int shift = 0;
+
+	uint8_t *src = (uint8_t *) (*dp)->d_buf + *offsetp;
+
+	do {
+		b = *src++;
+
+		ret |= ((b & 0x7f) << shift);
+
+		(*offsetp)++;
+
+		shift += 7;
+	} while ((b & 0x80) != 0);
+
+	if (shift < 32 && (b & 0x40) != 0)
+		ret |= (-1 << shift);
+
+	return ret;
+}
+
+static uint64_t
+dwarf_read_uleb128(Elf_Data **dp, uint64_t *offsetp)
+{
+	uint64_t ret = 0;
+	uint8_t b;
+	int shift = 0;
+
+	uint8_t *src = (uint8_t *) (*dp)->d_buf + *offsetp;
+
+	do {
+		b = *src++;
+
+		ret |= ((b & 0x7f) << shift);
+
+		(*offsetp)++;
+
+		shift += 7;
+	} while ((b & 0x80) != 0);
+
+	return ret;
+}
+
+static const char *
+dwarf_read_string(Elf_Data **dp, uint64_t *offsetp)
+{
+	char *ret;
+
+	char *src = (char *) (*dp)->d_buf + *offsetp;
+
+	ret = src;
+
+	while (*src != '\0' && *offsetp < (*dp)->d_size) {
+		src++;
+		(*offsetp)++;
+	}
+
+	if (*src == '\0' && *offsetp < (*dp)->d_size)
+		(*offsetp)++;
+
+	return ret;
+}
+
+static uint8_t *
+dwarf_read_block(Elf_Data **dp, uint64_t *offsetp, uint64_t length)
+{
+	uint8_t *ret;
+
+	uint8_t *src = (char *) (*dp)->d_buf + *offsetp;
+
+	ret = src;
+
+	(*offsetp) += length;
+
+	return ret;
+}
+
+static int
+dwarf_apply_relocations(Dwarf_Debug dbg, Elf_Data *reld, int secindx)
+{
+	Elf_Data *d;
+	GElf_Rela rela;
+	int indx = 0;
+	int ret = DWARF_E_NONE;
+	uint64_t offset;
+
+	/* Point to the data to be relocated: */
+	d = dbg->dbg_s[secindx].s_data;
+
+	/* Enter a loop to process each relocation addend: */
+	while (gelf_getrela(reld, indx++, &rela) != NULL) {
+		GElf_Sym sym;
+		Elf64_Xword symindx = ELF64_R_SYM(rela.r_info);
+
+		if (gelf_getsym(dbg->dbg_s[DWARF_symtab].s_data, symindx, &sym) == NULL) {
+			printf("Couldn't find symbol index %lu for relocation\n",(u_long) symindx);
+			continue;
+		}
+
+		offset = rela.r_offset;
+
+		dwarf_write(&d, &offset, rela.r_addend, dbg->dbg_offsize);
+	}
+
+	return ret;
+}
+
+static int
+dwarf_relocate(Dwarf_Debug dbg, Dwarf_Error *error)
+{
+	Elf_Scn *scn = NULL;
+	GElf_Shdr shdr;
+	int i;
+	int ret = DWARF_E_NONE;
+
+	/* Look for sections which relocate the debug sections. */
+	while ((scn = elf_nextscn(dbg->dbg_elf, scn)) != NULL) {
+		if (gelf_getshdr(scn, &shdr) == NULL) {
+			DWARF_SET_ELF_ERROR(error, elf_errno());
+			return DWARF_E_ELF;
+		}
+
+		if (shdr.sh_type != SHT_RELA || shdr.sh_size == 0)
+			continue;
+
+		for (i = 0; i < DWARF_DEBUG_SNAMES; i++) {
+			if (dbg->dbg_s[i].s_shnum == shdr.sh_info &&
+			    dbg->dbg_s[DWARF_symtab].s_shnum == shdr.sh_link) {
+				Elf_Data *rd;
+
+				/* Get the relocation data. */
+				if ((rd = elf_getdata(scn, NULL)) == NULL) {
+					DWARF_SET_ELF_ERROR(error, elf_errno());
+					return DWARF_E_ELF;
+				}
+
+				/* Apply the relocations. */
+				dwarf_apply_relocations(dbg, rd, i);
+				break;
+			}
+		}
+	}
+
+	return ret;
+}
+
+static int
+dwarf_init_attr(Dwarf_Debug dbg, Elf_Data **dp, uint64_t *offsetp,
+    Dwarf_CU cu, Dwarf_Die die, Dwarf_Attribute at, uint64_t form,
+    Dwarf_Error *error)
+{
+	int ret = DWARF_E_NONE;
+	struct _Dwarf_AttrValue avref;
+
+	memset(&avref, 0, sizeof(avref));
+	avref.av_attrib	= at->at_attrib;
+	avref.av_form	= at->at_form;
+
+	switch (form) {
+	case DW_FORM_addr:
+		avref.u[0].u64 = dwarf_read(dp, offsetp, cu->cu_pointer_size);
+		break;
+	case DW_FORM_block:
+		avref.u[0].u64 = dwarf_read_uleb128(dp, offsetp);
+		avref.u[1].u8p = dwarf_read_block(dp, offsetp, avref.u[0].u64);
+		break;
+	case DW_FORM_block1:
+		avref.u[0].u64 = dwarf_read(dp, offsetp, 1);
+		avref.u[1].u8p = dwarf_read_block(dp, offsetp, avref.u[0].u64);
+		break;
+	case DW_FORM_block2:
+		avref.u[0].u64 = dwarf_read(dp, offsetp, 2);
+		avref.u[1].u8p = dwarf_read_block(dp, offsetp, avref.u[0].u64);
+		break;
+	case DW_FORM_block4:
+		avref.u[0].u64 = dwarf_read(dp, offsetp, 4);
+		avref.u[1].u8p = dwarf_read_block(dp, offsetp, avref.u[0].u64);
+		break;
+	case DW_FORM_data1:
+	case DW_FORM_flag:
+	case DW_FORM_ref1:
+		avref.u[0].u64 = dwarf_read(dp, offsetp, 1);
+		break;
+	case DW_FORM_data2:
+	case DW_FORM_ref2:
+		avref.u[0].u64 = dwarf_read(dp, offsetp, 2);
+		break;
+	case DW_FORM_data4:
+	case DW_FORM_ref4:
+		avref.u[0].u64 = dwarf_read(dp, offsetp, 4);
+		break;
+	case DW_FORM_data8:
+	case DW_FORM_ref8:
+		avref.u[0].u64 = dwarf_read(dp, offsetp, 8);
+		break;
+	case DW_FORM_indirect:
+		form = dwarf_read_uleb128(dp, offsetp);
+		return dwarf_init_attr(dbg, dp, offsetp, cu, die, at, form, error);
+	case DW_FORM_ref_addr:
+		if (cu->cu_version == 2)
+			avref.u[0].u64 = dwarf_read(dp, offsetp, cu->cu_pointer_size);
+		else if (cu->cu_version == 3)
+			avref.u[0].u64 = dwarf_read(dp, offsetp, dbg->dbg_offsize);
+		break;
+	case DW_FORM_ref_udata:
+	case DW_FORM_udata:
+		avref.u[0].u64 = dwarf_read_uleb128(dp, offsetp);
+		break;
+	case DW_FORM_sdata:
+		avref.u[0].s64 = dwarf_read_sleb128(dp, offsetp);
+		break;
+	case DW_FORM_string:
+		avref.u[0].s = dwarf_read_string(dp, offsetp);
+		break;
+	case DW_FORM_strp:
+		avref.u[0].u64 = dwarf_read(dp, offsetp, dbg->dbg_offsize);
+		avref.u[1].s = elf_strptr(dbg->dbg_elf,
+		    dbg->dbg_s[DWARF_debug_str].s_shnum, avref.u[0].u64);
+		break;
+	default:
+		DWARF_SET_ERROR(error, DWARF_E_NOT_IMPLEMENTED);
+		ret = DWARF_E_NOT_IMPLEMENTED;
+		break;
+	}
+
+	if (ret == DWARF_E_NONE)
+		ret = dwarf_attrval_add(die, &avref, NULL, error);
+
+	return ret;
+}
+
+static int
+dwarf_init_abbrev(Dwarf_Debug dbg, Dwarf_CU cu, Dwarf_Error *error)
+{
+	Dwarf_Abbrev a;
+	Elf_Data *d;
+	int ret = DWARF_E_NONE;
+	uint64_t attr;
+	uint64_t entry;
+	uint64_t form;
+	uint64_t offset;
+	uint64_t tag;
+	u_int8_t children;
+
+	d = dbg->dbg_s[DWARF_debug_abbrev].s_data;
+
+	offset = cu->cu_abbrev_offset;
+
+	while (offset < d->d_size) {
+
+		entry = dwarf_read_uleb128(&d, &offset);
+
+		/* Check if this is the end of the data: */
+		if (entry == 0)
+			break;
+
+		tag = dwarf_read_uleb128(&d, &offset);
+
+		children = dwarf_read(&d, &offset, 1);
+
+		if ((ret = dwarf_abbrev_add(cu, entry, tag, children, &a, error)) != DWARF_E_NONE)
+			break;
+
+		do {
+			attr = dwarf_read_uleb128(&d, &offset);
+			form = dwarf_read_uleb128(&d, &offset);
+
+			if (attr != 0)
+				if ((ret = dwarf_attr_add(a, attr, form, NULL, error)) != DWARF_E_NONE)
+					return ret;
+		} while (attr != 0);
+	}
+
+	return ret;
+}
+
+static int
+dwarf_init_info(Dwarf_Debug dbg, Dwarf_Error *error)
+{
+	Dwarf_CU cu;
+	Elf_Data *d = NULL;
+	Elf_Scn *scn;
+	int i;
+	int level = 0;
+	int relocated = 0;
+	int ret = DWARF_E_NONE;
+	uint64_t length;
+	uint64_t next_offset;
+	uint64_t offset = 0;
+
+	scn = dbg->dbg_s[DWARF_debug_info].s_scn;
+
+	d = dbg->dbg_s[DWARF_debug_info].s_data;
+
+	while (offset < d->d_size) {
+		/* Allocate memory for the first compilation unit. */
+		if ((cu = calloc(sizeof(struct _Dwarf_CU), 1)) == NULL) {
+			DWARF_SET_ERROR(error, DWARF_E_MEMORY);
+			return DWARF_E_MEMORY;
+		}
+
+		/* Save the offet to this compilation unit: */
+		cu->cu_offset = offset;
+
+		length = dwarf_read(&d, &offset, 4);
+		if (length == 0xffffffff) {
+			length = dwarf_read(&d, &offset, 8);
+			dbg->dbg_offsize = 8;
+		} else
+			dbg->dbg_offsize = 4;
+
+		/*
+		 * Check if there is enough ELF data for this CU.
+		 * This assumes that libelf gives us the entire
+		 * section in one Elf_Data object.
+		 */
+		if (length > d->d_size - offset) {
+			free(cu);
+			DWARF_SET_ERROR(error, DWARF_E_INVALID_CU);
+			return DWARF_E_INVALID_CU;
+		}
+
+		/* Relocate the DWARF sections if necessary: */
+		if (!relocated) {
+			if ((ret = dwarf_relocate(dbg, error)) != DWARF_E_NONE)
+				return ret;
+			relocated = 1;
+		}
+
+		/* Compute the offset to the next compilation unit: */
+		next_offset = offset + length;
+
+		/* Initialise the compilation unit. */
+		cu->cu_length 		= length;
+		cu->cu_header_length	= (dbg->dbg_offsize == 4) ? 4 : 12;
+		cu->cu_version		= dwarf_read(&d, &offset, 2);
+		cu->cu_abbrev_offset	= dwarf_read(&d, &offset, dbg->dbg_offsize);
+		cu->cu_pointer_size	= dwarf_read(&d, &offset, 1);
+		cu->cu_next_offset	= next_offset;
+
+		/* Initialise the list of abbrevs. */
+		STAILQ_INIT(&cu->cu_abbrev);
+
+		/* Initialise the list of dies. */
+		STAILQ_INIT(&cu->cu_die);
+
+		/* Initialise the hash table of dies. */
+		for (i = 0; i < DWARF_DIE_HASH_SIZE; i++)
+			STAILQ_INIT(&cu->cu_die_hash[i]);
+
+		/* Add the compilation unit to the list. */
+		STAILQ_INSERT_TAIL(&dbg->dbg_cu, cu, cu_next);
+
+		if (cu->cu_version != 2 && cu->cu_version != 3) {
+			DWARF_SET_ERROR(error, DWARF_E_CU_VERSION);
+			ret = DWARF_E_CU_VERSION;
+			break;
+		}
+
+		/* Parse the .debug_abbrev info for this CU: */
+		if ((ret = dwarf_init_abbrev(dbg, cu, error)) != DWARF_E_NONE)
+			break;
+
+		level = 0;
+
+		while (offset < next_offset && offset < d->d_size) {
+			Dwarf_Abbrev a;
+			Dwarf_Attribute at;
+			Dwarf_Die die;
+			uint64_t abnum;
+			uint64_t die_offset = offset;;
+
+			abnum = dwarf_read_uleb128(&d, &offset);
+
+			if (abnum == 0) {
+				level--;
+				continue;
+			}
+
+			if ((a = dwarf_abbrev_find(cu, abnum)) == NULL) {
+				DWARF_SET_ERROR(error, DWARF_E_MISSING_ABBREV);
+				return DWARF_E_MISSING_ABBREV;
+			}
+
+			if ((ret = dwarf_die_add(cu, level, die_offset,
+			    abnum, a, &die, error)) != DWARF_E_NONE)
+				return ret;
+
+			STAILQ_FOREACH(at, &a->a_attrib, at_next) {
+				if ((ret = dwarf_init_attr(dbg, &d, &offset,
+				    cu, die, at, at->at_form, error)) != DWARF_E_NONE)
+					return ret;
+			}
+
+			if (a->a_children == DW_CHILDREN_yes)
+				level++;
+		}
+
+		offset = next_offset;
+	}
+
+	return ret;
+}
+
+static int
+dwarf_elf_read(Dwarf_Debug dbg, Dwarf_Error *error)
+{
+	GElf_Shdr shdr;
+	Elf_Scn *scn = NULL;
+	char *sname;
+	int i;
+	int ret = DWARF_E_NONE;
+
+	/* Get a copy of the ELF header. */
+	if (gelf_getehdr(dbg->dbg_elf, &dbg->dbg_ehdr) == NULL) {
+		DWARF_SET_ELF_ERROR(error, elf_errno());
+		return DWARF_E_ELF;
+	}
+
+	/* Check the ELF data format: */
+	switch (dbg->dbg_ehdr.e_ident[EI_DATA]) {
+	case ELFDATA2MSB:
+		dwarf_read = dwarf_read_msb;
+		dwarf_write = dwarf_write_msb;
+		break;
+
+	case ELFDATA2LSB:
+	case ELFDATANONE:
+	default:
+		dwarf_read = dwarf_read_lsb;
+		dwarf_write = dwarf_write_lsb;
+		break;
+	}
+
+	/* Get the section index to the string table. */
+	if (elf_getshstrndx(dbg->dbg_elf, &dbg->dbg_stnum) == 0) {
+		DWARF_SET_ELF_ERROR(error, elf_errno());
+		return DWARF_E_ELF;
+	}
+
+	/* Look for the debug sections. */
+	while ((scn = elf_nextscn(dbg->dbg_elf, scn)) != NULL) {
+		/* Get a copy of the section header: */
+		if (gelf_getshdr(scn, &shdr) == NULL) {
+			DWARF_SET_ELF_ERROR(error, elf_errno());
+			return DWARF_E_ELF;
+		}
+
+		/* Get a pointer to the section name: */
+		if ((sname = elf_strptr(dbg->dbg_elf, dbg->dbg_stnum, shdr.sh_name)) == NULL) {
+			DWARF_SET_ELF_ERROR(error, elf_errno());
+			return DWARF_E_ELF;
+		}
+
+		/*
+		 * Look up the section name to check if it's
+		 * one we need for DWARF.
+		 */
+		for (i = 0; i < DWARF_DEBUG_SNAMES; i++) {
+			if (strcmp(sname, debug_snames[i]) == 0) {
+				dbg->dbg_s[i].s_sname = sname;
+				dbg->dbg_s[i].s_shnum = elf_ndxscn(scn);
+				dbg->dbg_s[i].s_scn = scn;
+				memcpy(&dbg->dbg_s[i].s_shdr, &shdr, sizeof(shdr));
+				if ((dbg->dbg_s[i].s_data = elf_getdata(scn, NULL)) == NULL) {
+					DWARF_SET_ELF_ERROR(error, elf_errno());
+					return DWARF_E_ELF;
+				}
+				break;
+			}
+		}
+	}
+
+	/* Check if any of the required sections are missing: */
+	if (dbg->dbg_s[DWARF_debug_abbrev].s_scn == NULL ||
+	    dbg->dbg_s[DWARF_debug_info].s_scn == NULL) {
+		/* Missing debug information. */
+		DWARF_SET_ERROR(error, DWARF_E_DEBUG_INFO);
+		return DWARF_E_DEBUG_INFO;
+	}
+
+	/* Initialise the compilation-units: */
+	ret = dwarf_init_info(dbg, error);
+
+	return ret;
+}
+
+int
+dwarf_elf_init(Elf *elf, int mode, Dwarf_Debug *ret_dbg, Dwarf_Error *error)
+{
+	Dwarf_Debug dbg;
+	int ret = DWARF_E_NONE;
+
+	if (error == NULL)
+		/* Can only return a generic error. */
+		return DWARF_E_ERROR;
+
+	if (elf == NULL || ret_dbg == NULL) {
+		DWARF_SET_ERROR(error, DWARF_E_ARGUMENT);
+		ret = DWARF_E_ARGUMENT;
+	} else if ((dbg = calloc(sizeof(struct _Dwarf_Debug), 1)) == NULL) {
+		DWARF_SET_ERROR(error, DWARF_E_MEMORY);
+		ret = DWARF_E_MEMORY;
+	} else {
+		dbg->dbg_elf		= elf;
+		dbg->dbg_elf_close 	= 0;
+		dbg->dbg_mode		= mode;
+
+		STAILQ_INIT(&dbg->dbg_cu);
+
+		*ret_dbg = dbg;
+
+		/* Read the ELF sections. */
+		ret = dwarf_elf_read(dbg, error);
+	}
+
+	return ret;
+}
+
+int
+dwarf_init(int fd, int mode, Dwarf_Debug *ret_dbg, Dwarf_Error *error)
+{
+	Dwarf_Error lerror;
+	Elf *elf;
+	Elf_Cmd	c;
+	int ret;
+
+	if (error == NULL)
+		/* Can only return a generic error. */
+		return DWARF_E_ERROR;
+
+	if (fd < 0 || ret_dbg == NULL) {
+		DWARF_SET_ERROR(error, DWARF_E_ARGUMENT);
+		return DWARF_E_ERROR;
+	}
+
+	/* Translate the DWARF mode to ELF mode. */
+	switch (mode) {
+	default:
+	case DW_DLC_READ:
+		c = ELF_C_READ;
+		break;
+	}
+
+	if (elf_version(EV_CURRENT) == EV_NONE) {
+		DWARF_SET_ELF_ERROR(error, elf_errno());
+		return DWARF_E_ERROR;
+	}
+
+	if ((elf = elf_begin(fd, c, NULL)) == NULL) {
+		DWARF_SET_ELF_ERROR(error, elf_errno());
+		return DWARF_E_ERROR;
+	}
+
+	ret = dwarf_elf_init(elf, mode, ret_dbg, error);
+
+	if (*ret_dbg != NULL)
+		/* Remember to close the ELF file. */
+		(*ret_dbg)->dbg_elf_close = 1;
+
+	if (ret != DWARF_E_NONE) {
+		if (*ret_dbg != NULL) {
+			dwarf_finish(ret_dbg, &lerror);
+		} else
+			elf_end(elf);
+	}
+
+	return ret;
+}