1 files changed, 474 insertions, 0 deletions

diff --git a/lib/libkldelf/ef_obj.c b/lib/libkldelf/ef_obj.c
new file mode 100644
index 000000000000..151bac74b17d
--- /dev/null
+++ b/lib/libkldelf/ef_obj.c
@@ -0,0 +1,474 @@
+/*-
+ * SPDX-License-Identifier: BSD-4-Clause
+ *
+ * Copyright (c) 2000, Boris Popov
+ * Copyright (c) 1998-2000 Doug Rabson
+ * Copyright (c) 2004 Peter Wemm
+ * 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.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *    This product includes software developed by Boris Popov.
+ * 4. Neither the name of the author nor the names of any co-contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * 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.
+ */
+
+#include <sys/param.h>
+
+#include <err.h>
+#include <errno.h>
+#include <gelf.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "kldelf.h"
+
+typedef struct {
+	GElf_Addr	addr;
+	GElf_Off	offset;
+	GElf_Off	size;
+	int		flags;
+	int		sec;	/* Original section */
+	char		*name;
+} Elf_progent;
+
+typedef struct {
+	GElf_Rel	*rel;
+	long		nrel;
+	int		sec;
+} Elf_relent;
+
+typedef struct {
+	GElf_Rela	*rela;
+	long		nrela;
+	int		sec;
+} Elf_relaent;
+
+struct ef_file {
+	char		*ef_name;
+	struct elf_file *ef_efile;
+
+	Elf_progent	*progtab;
+	int		nprogtab;
+
+	Elf_relaent	*relatab;
+	int		nrela;
+
+	Elf_relent	*reltab;
+	int		nrel;
+
+	GElf_Sym	*ddbsymtab;	/* The symbol table we are using */
+	size_t		ddbsymcnt;	/* Number of symbols */
+	caddr_t		ddbstrtab;	/* String table */
+	long		ddbstrcnt;	/* number of bytes in string table */
+
+	caddr_t		shstrtab;	/* Section name string table */
+	long		shstrcnt;	/* number of bytes in string table */
+
+	int		ef_verbose;
+};
+
+static void	ef_obj_close(elf_file_t ef);
+
+static int	ef_obj_seg_read_rel(elf_file_t ef, GElf_Addr address,
+		    size_t len, void *dest);
+static int	ef_obj_seg_read_string(elf_file_t ef, GElf_Addr address,
+		    size_t len, char *dest);
+
+static GElf_Addr ef_obj_symaddr(elf_file_t ef, GElf_Size symidx);
+static int	ef_obj_lookup_set(elf_file_t ef, const char *name,
+		    GElf_Addr *startp, GElf_Addr *stopp, long *countp);
+static int	ef_obj_lookup_symbol(elf_file_t ef, const char *name,
+		    GElf_Sym **sym, bool see_local);
+
+static struct elf_file_ops ef_obj_file_ops = {
+	.close			= ef_obj_close,
+	.seg_read_rel		= ef_obj_seg_read_rel,
+	.seg_read_string	= ef_obj_seg_read_string,
+	.symaddr		= ef_obj_symaddr,
+	.lookup_set		= ef_obj_lookup_set,
+	.lookup_symbol		= ef_obj_lookup_symbol,
+};
+
+static GElf_Off
+ef_obj_get_offset(elf_file_t ef, GElf_Addr addr)
+{
+	Elf_progent *pt;
+	int i;
+
+	for (i = 0; i < ef->nprogtab; i++) {
+		pt = &ef->progtab[i];
+		if (pt->offset == (GElf_Off)-1)
+			continue;
+		if (addr >= pt->addr && addr < pt->addr + pt->size)
+			return (pt->offset + (addr - pt->addr));
+	}
+	return (0);
+}
+
+static int
+ef_obj_lookup_symbol(elf_file_t ef, const char *name, GElf_Sym **sym,
+    bool see_local)
+{
+	GElf_Sym *symp;
+	const char *strp;
+	int i;
+
+	for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
+		strp = ef->ddbstrtab + symp->st_name;
+		if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
+			if (see_local ||
+			    GELF_ST_BIND(symp->st_info) != STB_LOCAL) {
+				*sym = symp;
+				return (0);
+			}
+		}
+	}
+	return (ENOENT);
+}
+
+static int
+ef_obj_lookup_set(elf_file_t ef, const char *name, GElf_Addr *startp,
+    GElf_Addr *stopp, long *countp)
+{
+	int i;
+
+	for (i = 0; i < ef->nprogtab; i++) {
+		if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
+		    strcmp(ef->progtab[i].name + 4, name) == 0) {
+			*startp = ef->progtab[i].addr;
+			*stopp = ef->progtab[i].addr + ef->progtab[i].size;
+			*countp = (*stopp - *startp) /
+			    elf_pointer_size(ef->ef_efile);
+			return (0);
+		}
+	}
+	return (ESRCH);
+}
+
+static GElf_Addr
+ef_obj_symaddr(elf_file_t ef, GElf_Size symidx)
+{
+	const GElf_Sym *sym;
+
+	if (symidx >= ef->ddbsymcnt)
+		return (0);
+	sym = ef->ddbsymtab + symidx;
+
+	if (sym->st_shndx != SHN_UNDEF)
+		return (sym->st_value);
+	return (0);
+}
+
+static int
+ef_obj_seg_read_rel(elf_file_t ef, GElf_Addr address, size_t len, void *dest)
+{
+	GElf_Off secofs;
+	GElf_Rel *r;
+	GElf_Rela *a;
+	GElf_Addr secbase, dataoff;
+	int error, i, sec;
+
+	/* Find out which section contains the data. */
+	sec = -1;
+	for (i = 0; i < ef->nprogtab; i++) {
+		if (address < ef->progtab[i].addr)
+			continue;
+
+		dataoff = address - ef->progtab[i].addr;
+		if (dataoff + len > ef->progtab[i].size)
+			continue;
+
+		sec = ef->progtab[i].sec;
+		secbase = ef->progtab[i].addr;
+		secofs = ef->progtab[i].offset;
+		break;
+	}
+
+	if (sec == -1) {
+		if (ef->ef_verbose)
+			warnx("ef_obj_seg_read_rel(%s): bad address (%jx)",
+			    ef->ef_name, (uintmax_t)address);
+		return (EFAULT);
+	}
+
+	if (secofs == (GElf_Off)-1) {
+		memset(dest, 0, len);
+	} else {
+		error = elf_read_raw_data(ef->ef_efile, secofs + dataoff, dest,
+		    len);
+		if (error != 0)
+			return (error);
+	}
+
+	/* Now do the relocations. */
+	for (i = 0; i < ef->nrel; i++) {
+		if (ef->reltab[i].sec != sec)
+			continue;
+		for (r = ef->reltab[i].rel;
+		     r < &ef->reltab[i].rel[ef->reltab[i].nrel]; r++) {
+			error = elf_reloc(ef->ef_efile, r, ELF_T_REL, secbase,
+			    address, len, dest);
+			if (error != 0)
+				return (error);
+		}
+	}
+	for (i = 0; i < ef->nrela; i++) {
+		if (ef->relatab[i].sec != sec)
+			continue;
+		for (a = ef->relatab[i].rela;
+		     a < &ef->relatab[i].rela[ef->relatab[i].nrela]; a++) {
+			error = elf_reloc(ef->ef_efile, a, ELF_T_RELA, secbase,
+			    address, len, dest);
+			if (error != 0)
+				return (error);
+		}
+	}
+	return (0);
+}
+
+static int
+ef_obj_seg_read_string(elf_file_t ef, GElf_Addr address, size_t len, char *dest)
+{
+	GElf_Off ofs;
+
+	ofs = ef_obj_get_offset(ef, address);
+	if (ofs == 0) {
+		if (ef->ef_verbose)
+			warnx("ef_obj_seg_read_string(%s): bad address (%jx)",
+			    ef->ef_name, (uintmax_t)address);
+		return (EFAULT);
+	}
+
+	return (elf_read_raw_string(ef->ef_efile, ofs, dest, len));
+}
+
+int
+ef_obj_open(struct elf_file *efile, int verbose)
+{
+	elf_file_t ef;
+	GElf_Ehdr *hdr;
+	GElf_Shdr *shdr;
+	GElf_Sym *es;
+	GElf_Addr mapbase;
+	size_t i, nshdr;
+	int error, pb, ra, rl;
+	int j, nsym, symstrindex, symtabindex;
+
+	hdr = &efile->ef_hdr;
+	if (hdr->e_type != ET_REL || hdr->e_shnum == 0 || hdr->e_shoff == 0 ||
+	    hdr->e_shentsize != elf_object_size(efile, ELF_T_SHDR))
+		return (EFTYPE);
+
+	ef = calloc(1, sizeof(*ef));
+	if (ef == NULL)
+		return (errno);
+
+	efile->ef_ef = ef;
+	efile->ef_ops = &ef_obj_file_ops;
+
+	ef->ef_verbose = verbose;
+	ef->ef_name = strdup(efile->ef_filename);
+	ef->ef_efile = efile;
+
+	error = elf_read_shdrs(efile, &nshdr, &shdr);
+	if (error != 0) {
+		shdr = NULL;
+		goto out;
+	}
+
+	/* Scan the section headers for information and table sizing. */
+	nsym = 0;
+	symtabindex = -1;
+	symstrindex = -1;
+	for (i = 0; i < nshdr; i++) {
+		switch (shdr[i].sh_type) {
+		case SHT_PROGBITS:
+		case SHT_NOBITS:
+			ef->nprogtab++;
+			break;
+		case SHT_SYMTAB:
+			nsym++;
+			symtabindex = i;
+			symstrindex = shdr[i].sh_link;
+			break;
+		case SHT_REL:
+			ef->nrel++;
+			break;
+		case SHT_RELA:
+			ef->nrela++;
+			break;
+		case SHT_STRTAB:
+			break;
+		}
+	}
+
+	if (ef->nprogtab == 0) {
+		warnx("%s: file has no contents", ef->ef_name);
+		goto out;
+	}
+	if (nsym != 1) {
+		warnx("%s: file has no valid symbol table", ef->ef_name);
+		goto out;
+	}
+	if (symstrindex < 0 || symstrindex > nshdr ||
+	    shdr[symstrindex].sh_type != SHT_STRTAB) {
+		warnx("%s: file has invalid symbol strings", ef->ef_name);
+		goto out;
+	}
+
+	/* Allocate space for tracking the load chunks */
+	if (ef->nprogtab != 0)
+		ef->progtab = calloc(ef->nprogtab, sizeof(*ef->progtab));
+	if (ef->nrel != 0)
+		ef->reltab = calloc(ef->nrel, sizeof(*ef->reltab));
+	if (ef->nrela != 0)
+		ef->relatab = calloc(ef->nrela, sizeof(*ef->relatab));
+	if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
+	    (ef->nrel != 0 && ef->reltab == NULL) ||
+	    (ef->nrela != 0 && ef->relatab == NULL)) {
+		warnx("malloc failed");
+		error = ENOMEM;
+		goto out;
+	}
+
+	if (elf_read_symbols(efile, symtabindex, &ef->ddbsymcnt,
+	    &ef->ddbsymtab) != 0) {
+		warnx("elf_read_symbols failed");
+		goto out;
+	}
+
+	if (elf_read_string_table(efile, &shdr[symstrindex], &ef->ddbstrcnt,
+	    &ef->ddbstrtab) != 0) {
+		warnx("elf_read_string_table failed");
+		goto out;
+	}
+
+	/* Do we have a string table for the section names?  */
+	if (hdr->e_shstrndx != 0 &&
+	    shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
+		if (elf_read_string_table(efile, &shdr[hdr->e_shstrndx],
+		    &ef->shstrcnt, &ef->shstrtab) != 0) {
+			warnx("elf_read_string_table failed");
+			goto out;
+		}
+	}
+
+	/*
+	 * Now allocate address space for code/data(progbits) and
+	 * bss(nobits) and allocate space for and load relocs.
+	 */
+	pb = 0;
+	rl = 0;
+	ra = 0;
+	mapbase = 0;
+	for (i = 0; i < nshdr; i++) {
+		switch (shdr[i].sh_type) {
+		case SHT_PROGBITS:
+		case SHT_NOBITS:
+			mapbase = roundup2(mapbase, shdr[i].sh_addralign);
+			ef->progtab[pb].addr = mapbase;
+			if (shdr[i].sh_type == SHT_PROGBITS) {
+				ef->progtab[pb].name = "<<PROGBITS>>";
+				ef->progtab[pb].offset = shdr[i].sh_offset;
+			} else {
+				ef->progtab[pb].name = "<<NOBITS>>";
+				ef->progtab[pb].offset = (GElf_Off)-1;
+			}
+			ef->progtab[pb].size = shdr[i].sh_size;
+			ef->progtab[pb].sec = i;
+			if (ef->shstrtab && shdr[i].sh_name != 0)
+				ef->progtab[pb].name =
+				    ef->shstrtab + shdr[i].sh_name;
+
+			/* Update all symbol values with the offset. */
+			for (j = 0; j < ef->ddbsymcnt; j++) {
+				es = &ef->ddbsymtab[j];
+				if (es->st_shndx != i)
+					continue;
+				es->st_value += ef->progtab[pb].addr;
+			}
+			mapbase += shdr[i].sh_size;
+			pb++;
+			break;
+		case SHT_REL:
+			ef->reltab[rl].sec = shdr[i].sh_info;
+			if (elf_read_rel(efile, i, &ef->reltab[rl].nrel,
+			    &ef->reltab[rl].rel) != 0) {
+				warnx("elf_read_rel failed");
+				goto out;
+			}
+			rl++;
+			break;
+		case SHT_RELA:
+			ef->relatab[ra].sec = shdr[i].sh_info;
+			if (elf_read_rela(efile, i, &ef->relatab[ra].nrela,
+			    &ef->relatab[ra].rela) != 0) {
+				warnx("elf_read_rela failed");
+				goto out;
+			}
+			ra++;
+			break;
+		}
+	}
+	error = 0;
+out:
+	free(shdr);
+	if (error != 0)
+		ef_obj_close(ef);
+	return (error);
+}
+
+static void
+ef_obj_close(elf_file_t ef)
+{
+	int i;
+
+	if (ef->ef_name)
+		free(ef->ef_name);
+	if (ef->nprogtab != 0)
+		free(ef->progtab);
+	if (ef->nrel != 0) {
+		for (i = 0; i < ef->nrel; i++)
+			if (ef->reltab[i].rel != NULL)
+				free(ef->reltab[i].rel);
+		free(ef->reltab);
+	}
+	if (ef->nrela != 0) {
+		for (i = 0; i < ef->nrela; i++)
+			if (ef->relatab[i].rela != NULL)
+				free(ef->relatab[i].rela);
+		free(ef->relatab);
+	}
+	if (ef->ddbsymtab != NULL)
+		free(ef->ddbsymtab);
+	if (ef->ddbstrtab != NULL)
+		free(ef->ddbstrtab);
+	if (ef->shstrtab != NULL)
+		free(ef->shstrtab);
+	ef->ef_efile->ef_ops = NULL;
+	ef->ef_efile->ef_ef = NULL;
+	free(ef);
+}