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a25349736d
sections and indirectly change the layout of an ELF file when ELF_F_LAYOUT is not set. PR: bin/167103 Approved by: rstone (co-mentor) Obtained from: elftoolchain MFC after: 2 weeks
969 lines
23 KiB
C
969 lines
23 KiB
C
/*-
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* Copyright (c) 2006-2008 Joseph Koshy
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/mman.h>
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#include <sys/param.h>
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#include <assert.h>
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#include <errno.h>
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#include <gelf.h>
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#include <libelf.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include "_libelf.h"
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/*
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* Layout strategy:
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*
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* - Case 1: ELF_F_LAYOUT is asserted
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* In this case the application has full control over where the
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* section header table, program header table, and section data
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* will reside. The library only perform error checks.
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*
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* - Case 2: ELF_F_LAYOUT is not asserted
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*
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* The library will do the object layout using the following
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* ordering:
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* - The executable header is placed first, are required by the
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* ELF specification.
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* - The program header table is placed immediately following the
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* executable header.
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* - Section data, if any, is placed after the program header
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* table, aligned appropriately.
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* - The section header table, if needed, is placed last.
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*
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* There are two sub-cases to be taken care of:
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*
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* - Case 2a: e->e_cmd == ELF_C_READ or ELF_C_RDWR
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*
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* In this sub-case, the underlying ELF object may already have
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* content in it, which the application may have modified. The
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* library will retrieve content from the existing object as
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* needed.
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*
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* - Case 2b: e->e_cmd == ELF_C_WRITE
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*
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* The ELF object is being created afresh in this sub-case;
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* there is no pre-existing content in the underlying ELF
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* object.
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*/
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/*
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* Compute the extents of a section, by looking at the data
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* descriptors associated with it. The function returns 1 if
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* successful, or zero if an error was detected.
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*/
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static int
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_libelf_compute_section_extents(Elf *e, Elf_Scn *s, off_t rc)
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{
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int ec;
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size_t fsz, msz;
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Elf_Data *d;
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Elf32_Shdr *shdr32;
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Elf64_Shdr *shdr64;
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unsigned int elftype;
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uint32_t sh_type;
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uint64_t d_align;
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uint64_t sh_align, sh_entsize, sh_offset, sh_size;
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uint64_t scn_size, scn_alignment;
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ec = e->e_class;
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shdr32 = &s->s_shdr.s_shdr32;
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shdr64 = &s->s_shdr.s_shdr64;
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if (ec == ELFCLASS32) {
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sh_type = shdr32->sh_type;
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sh_align = (uint64_t) shdr32->sh_addralign;
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sh_entsize = (uint64_t) shdr32->sh_entsize;
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sh_offset = (uint64_t) shdr32->sh_offset;
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sh_size = (uint64_t) shdr32->sh_size;
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} else {
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sh_type = shdr64->sh_type;
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sh_align = shdr64->sh_addralign;
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sh_entsize = shdr64->sh_entsize;
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sh_offset = shdr64->sh_offset;
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sh_size = shdr64->sh_size;
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}
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assert(sh_type != SHT_NULL && sh_type != SHT_NOBITS);
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elftype = _libelf_xlate_shtype(sh_type);
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if (elftype > ELF_T_LAST) {
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LIBELF_SET_ERROR(SECTION, 0);
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return (0);
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}
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if (sh_align == 0)
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sh_align = _libelf_falign(elftype, ec);
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/*
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* Check the section's data buffers for sanity and compute the
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* section's alignment.
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* Compute the section's size and alignment using the data
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* descriptors associated with the section.
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*/
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if (STAILQ_EMPTY(&s->s_data)) {
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/*
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* The section's content (if any) has not been read in
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* yet. If section is not dirty marked dirty, we can
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* reuse the values in the 'sh_size' and 'sh_offset'
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* fields of the section header.
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*/
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if ((s->s_flags & ELF_F_DIRTY) == 0) {
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/*
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* If the library is doing the layout, then we
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* compute the new start offset for the
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* section based on the current offset and the
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* section's alignment needs.
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*
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* If the application is doing the layout, we
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* can use the value in the 'sh_offset' field
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* in the section header directly.
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*/
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if (e->e_flags & ELF_F_LAYOUT)
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goto updatedescriptor;
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else
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goto computeoffset;
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}
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/*
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* Otherwise, we need to bring in the section's data
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* from the underlying ELF object.
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*/
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if (e->e_cmd != ELF_C_WRITE && elf_getdata(s, NULL) == NULL)
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return (0);
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}
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/*
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* Loop through the section's data descriptors.
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*/
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scn_size = 0L;
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scn_alignment = 0L;
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STAILQ_FOREACH(d, &s->s_data, d_next) {
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if (d->d_type > ELF_T_LAST) {
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LIBELF_SET_ERROR(DATA, 0);
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return (0);
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}
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if (d->d_version != e->e_version) {
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LIBELF_SET_ERROR(VERSION, 0);
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return (0);
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}
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if ((d_align = d->d_align) == 0 || (d_align & (d_align - 1))) {
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LIBELF_SET_ERROR(DATA, 0);
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return (0);
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}
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/*
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* The buffer's size should be a multiple of the
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* memory size of the underlying type.
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*/
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msz = _libelf_msize(d->d_type, ec, e->e_version);
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if (d->d_size % msz) {
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LIBELF_SET_ERROR(DATA, 0);
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return (0);
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}
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/*
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* Compute the section's size.
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*/
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if (e->e_flags & ELF_F_LAYOUT) {
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if ((uint64_t) d->d_off + d->d_size > scn_size)
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scn_size = d->d_off + d->d_size;
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} else {
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scn_size = roundup2(scn_size, d->d_align);
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d->d_off = scn_size;
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fsz = _libelf_fsize(d->d_type, ec, d->d_version,
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d->d_size / msz);
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scn_size += fsz;
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}
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/*
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* The section's alignment is the maximum alignment
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* needed for its data buffers.
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*/
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if (d_align > scn_alignment)
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scn_alignment = d_align;
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}
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/*
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* If the application is requesting full control over the layout
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* of the section, check its values for sanity.
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*/
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if (e->e_flags & ELF_F_LAYOUT) {
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if (scn_alignment > sh_align || sh_offset % sh_align ||
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sh_size < scn_size) {
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LIBELF_SET_ERROR(LAYOUT, 0);
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return (0);
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}
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goto updatedescriptor;
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}
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/*
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* Otherwise compute the values in the section header.
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*
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* The section alignment is the maximum alignment for any of
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* its contained data descriptors.
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*/
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if (scn_alignment > sh_align)
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sh_align = scn_alignment;
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/*
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* If the section entry size is zero, try and fill in an
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* appropriate entry size. Per the elf(5) manual page
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* sections without fixed-size entries should have their
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* 'sh_entsize' field set to zero.
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*/
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if (sh_entsize == 0 &&
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(sh_entsize = _libelf_fsize(elftype, ec, e->e_version,
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(size_t) 1)) == 1)
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sh_entsize = 0;
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sh_size = scn_size;
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computeoffset:
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/*
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* Compute the new offset for the section based on
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* the section's alignment needs.
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*/
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sh_offset = roundup(rc, sh_align);
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/*
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* Update the section header.
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*/
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if (ec == ELFCLASS32) {
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shdr32->sh_addralign = (uint32_t) sh_align;
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shdr32->sh_entsize = (uint32_t) sh_entsize;
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shdr32->sh_offset = (uint32_t) sh_offset;
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shdr32->sh_size = (uint32_t) sh_size;
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} else {
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shdr64->sh_addralign = sh_align;
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shdr64->sh_entsize = sh_entsize;
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shdr64->sh_offset = sh_offset;
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shdr64->sh_size = sh_size;
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}
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updatedescriptor:
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/*
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* Update the section descriptor.
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*/
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s->s_size = sh_size;
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s->s_offset = sh_offset;
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return (1);
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}
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/*
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* Insert a section in ascending order in the list
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*/
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static int
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_libelf_insert_section(Elf *e, Elf_Scn *s)
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{
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Elf_Scn *t, *prevt;
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uint64_t smax, smin, tmax, tmin;
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smin = s->s_offset;
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smax = smin + s->s_size;
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prevt = NULL;
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STAILQ_FOREACH(t, &e->e_u.e_elf.e_scn, s_next) {
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tmin = t->s_offset;
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tmax = tmin + t->s_size;
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if (tmax <= smin) {
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/*
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* 't' lies entirely before 's': ...| t |...| s |...
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*/
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prevt = t;
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continue;
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} else if (smax <= tmin)
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/*
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* 's' lies entirely before 't', and after 'prevt':
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* ...| prevt |...| s |...| t |...
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*/
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break;
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else { /* 's' and 't' overlap. */
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LIBELF_SET_ERROR(LAYOUT, 0);
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return (0);
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}
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}
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if (prevt)
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STAILQ_INSERT_AFTER(&e->e_u.e_elf.e_scn, prevt, s, s_next);
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else
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STAILQ_INSERT_HEAD(&e->e_u.e_elf.e_scn, s, s_next);
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return (1);
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}
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/*
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* Recompute section layout.
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*/
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static off_t
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_libelf_resync_sections(Elf *e, off_t rc)
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{
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int ec;
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Elf_Scn *s;
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size_t sh_type, shdr_start, shdr_end;
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ec = e->e_class;
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/*
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* Make a pass through sections, computing the extent of each
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* section. Order in increasing order of addresses.
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*/
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STAILQ_FOREACH(s, &e->e_u.e_elf.e_scn, s_next) {
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if (ec == ELFCLASS32)
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sh_type = s->s_shdr.s_shdr32.sh_type;
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else
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sh_type = s->s_shdr.s_shdr64.sh_type;
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if (sh_type == SHT_NOBITS || sh_type == SHT_NULL)
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continue;
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if (_libelf_compute_section_extents(e, s, rc) == 0)
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return ((off_t) -1);
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if (s->s_size == 0)
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continue;
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if (s->s_offset + s->s_size < (size_t) rc) {
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/*
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* Try insert this section in the
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* correct place in the list,
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* detecting overlaps if any.
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*/
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STAILQ_REMOVE(&e->e_u.e_elf.e_scn, s, _Elf_Scn,
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s_next);
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if (_libelf_insert_section(e, s) == 0)
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return ((off_t) -1);
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} else
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rc = s->s_offset + s->s_size;
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}
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/*
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* If the application is controlling file layout, check for an
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* overlap between this section's extents and the SHDR table.
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*/
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if (e->e_flags & ELF_F_LAYOUT) {
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if (e->e_class == ELFCLASS32)
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shdr_start = e->e_u.e_elf.e_ehdr.e_ehdr32->e_shoff;
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else
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shdr_start = e->e_u.e_elf.e_ehdr.e_ehdr64->e_shoff;
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shdr_end = shdr_start + _libelf_fsize(ELF_T_SHDR, e->e_class,
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e->e_version, e->e_u.e_elf.e_nscn);
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STAILQ_FOREACH(s, &e->e_u.e_elf.e_scn, s_next) {
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if (s->s_offset >= shdr_end ||
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s->s_offset + s->s_size <= shdr_start)
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continue;
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LIBELF_SET_ERROR(LAYOUT, 0);
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return ((off_t) -1);
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}
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}
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return (rc);
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}
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static off_t
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_libelf_resync_elf(Elf *e)
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{
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int ec, eh_class, eh_type;
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unsigned int eh_byteorder, eh_version;
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size_t align, fsz;
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size_t phnum, shnum;
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off_t rc, phoff, shoff;
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void *ehdr;
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Elf32_Ehdr *eh32;
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Elf64_Ehdr *eh64;
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rc = 0;
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ec = e->e_class;
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assert(ec == ELFCLASS32 || ec == ELFCLASS64);
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/*
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* Prepare the EHDR.
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*/
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if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL)
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return ((off_t) -1);
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eh32 = ehdr;
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eh64 = ehdr;
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if (ec == ELFCLASS32) {
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eh_byteorder = eh32->e_ident[EI_DATA];
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eh_class = eh32->e_ident[EI_CLASS];
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phoff = (uint64_t) eh32->e_phoff;
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shoff = (uint64_t) eh32->e_shoff;
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eh_type = eh32->e_type;
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eh_version = eh32->e_version;
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} else {
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eh_byteorder = eh64->e_ident[EI_DATA];
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eh_class = eh64->e_ident[EI_CLASS];
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phoff = eh64->e_phoff;
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shoff = eh64->e_shoff;
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eh_type = eh64->e_type;
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eh_version = eh64->e_version;
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}
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if (eh_version == EV_NONE)
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eh_version = EV_CURRENT;
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if (eh_version != e->e_version) { /* always EV_CURRENT */
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LIBELF_SET_ERROR(VERSION, 0);
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return ((off_t) -1);
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}
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if (eh_class != e->e_class) {
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LIBELF_SET_ERROR(CLASS, 0);
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return ((off_t) -1);
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}
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if (e->e_cmd != ELF_C_WRITE && eh_byteorder != e->e_byteorder) {
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LIBELF_SET_ERROR(HEADER, 0);
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return ((off_t) -1);
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}
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shnum = e->e_u.e_elf.e_nscn;
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phnum = e->e_u.e_elf.e_nphdr;
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e->e_byteorder = eh_byteorder;
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#define INITIALIZE_EHDR(E,EC,V) do { \
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(E)->e_ident[EI_MAG0] = ELFMAG0; \
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(E)->e_ident[EI_MAG1] = ELFMAG1; \
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(E)->e_ident[EI_MAG2] = ELFMAG2; \
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(E)->e_ident[EI_MAG3] = ELFMAG3; \
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(E)->e_ident[EI_CLASS] = (EC); \
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(E)->e_ident[EI_VERSION] = (V); \
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(E)->e_ehsize = _libelf_fsize(ELF_T_EHDR, (EC), (V), \
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(size_t) 1); \
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(E)->e_phentsize = (phnum == 0) ? 0 : _libelf_fsize( \
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ELF_T_PHDR, (EC), (V), (size_t) 1); \
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(E)->e_shentsize = _libelf_fsize(ELF_T_SHDR, (EC), (V), \
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(size_t) 1); \
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} while (0)
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if (ec == ELFCLASS32)
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INITIALIZE_EHDR(eh32, ec, eh_version);
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else
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INITIALIZE_EHDR(eh64, ec, eh_version);
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(void) elf_flagehdr(e, ELF_C_SET, ELF_F_DIRTY);
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rc += _libelf_fsize(ELF_T_EHDR, ec, eh_version, (size_t) 1);
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/*
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* Compute the layout the program header table, if one is
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* present. The program header table needs to be aligned to a
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* `natural' boundary.
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*/
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if (phnum) {
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|
fsz = _libelf_fsize(ELF_T_PHDR, ec, eh_version, phnum);
|
|
align = _libelf_falign(ELF_T_PHDR, ec);
|
|
|
|
if (e->e_flags & ELF_F_LAYOUT) {
|
|
/*
|
|
* Check offsets for sanity.
|
|
*/
|
|
if (rc > phoff) {
|
|
LIBELF_SET_ERROR(HEADER, 0);
|
|
return ((off_t) -1);
|
|
}
|
|
|
|
if (phoff % align) {
|
|
LIBELF_SET_ERROR(LAYOUT, 0);
|
|
return ((off_t) -1);
|
|
}
|
|
|
|
} else
|
|
phoff = roundup(rc, align);
|
|
|
|
rc = phoff + fsz;
|
|
} else
|
|
phoff = 0;
|
|
|
|
/*
|
|
* Compute the layout of the sections associated with the
|
|
* file.
|
|
*/
|
|
|
|
if (e->e_cmd != ELF_C_WRITE &&
|
|
(e->e_flags & LIBELF_F_SHDRS_LOADED) == 0 &&
|
|
_libelf_load_scn(e, ehdr) == 0)
|
|
return ((off_t) -1);
|
|
|
|
if ((rc = _libelf_resync_sections(e, rc)) < 0)
|
|
return ((off_t) -1);
|
|
|
|
/*
|
|
* Compute the space taken up by the section header table, if
|
|
* one is needed. If ELF_F_LAYOUT is asserted, the
|
|
* application may have placed the section header table in
|
|
* between existing sections, so the net size of the file need
|
|
* not increase due to the presence of the section header
|
|
* table.
|
|
*/
|
|
if (shnum) {
|
|
fsz = _libelf_fsize(ELF_T_SHDR, ec, eh_version, (size_t) 1);
|
|
align = _libelf_falign(ELF_T_SHDR, ec);
|
|
|
|
if (e->e_flags & ELF_F_LAYOUT) {
|
|
if (shoff % align) {
|
|
LIBELF_SET_ERROR(LAYOUT, 0);
|
|
return ((off_t) -1);
|
|
}
|
|
} else
|
|
shoff = roundup(rc, align);
|
|
|
|
if (shoff + fsz * shnum > (size_t) rc)
|
|
rc = shoff + fsz * shnum;
|
|
} else
|
|
shoff = 0;
|
|
|
|
/*
|
|
* Set the fields of the Executable Header that could potentially use
|
|
* extended numbering.
|
|
*/
|
|
_libelf_setphnum(e, ehdr, ec, phnum);
|
|
_libelf_setshnum(e, ehdr, ec, shnum);
|
|
|
|
/*
|
|
* Update the `e_phoff' and `e_shoff' fields if the library is
|
|
* doing the layout.
|
|
*/
|
|
if ((e->e_flags & ELF_F_LAYOUT) == 0) {
|
|
if (ec == ELFCLASS32) {
|
|
eh32->e_phoff = (uint32_t) phoff;
|
|
eh32->e_shoff = (uint32_t) shoff;
|
|
} else {
|
|
eh64->e_phoff = (uint64_t) phoff;
|
|
eh64->e_shoff = (uint64_t) shoff;
|
|
}
|
|
}
|
|
|
|
return (rc);
|
|
}
|
|
|
|
/*
|
|
* Write out the contents of a section.
|
|
*/
|
|
|
|
static off_t
|
|
_libelf_write_scn(Elf *e, char *nf, Elf_Scn *s, off_t rc)
|
|
{
|
|
int ec;
|
|
size_t fsz, msz, nobjects;
|
|
uint32_t sh_type;
|
|
uint64_t sh_off, sh_size;
|
|
int elftype;
|
|
Elf_Data *d, dst;
|
|
|
|
if ((ec = e->e_class) == ELFCLASS32) {
|
|
sh_type = s->s_shdr.s_shdr32.sh_type;
|
|
sh_size = (uint64_t) s->s_shdr.s_shdr32.sh_size;
|
|
} else {
|
|
sh_type = s->s_shdr.s_shdr64.sh_type;
|
|
sh_size = s->s_shdr.s_shdr64.sh_size;
|
|
}
|
|
|
|
/*
|
|
* Ignore sections that do not allocate space in the file.
|
|
*/
|
|
if (sh_type == SHT_NOBITS || sh_type == SHT_NULL || sh_size == 0)
|
|
return (rc);
|
|
|
|
elftype = _libelf_xlate_shtype(sh_type);
|
|
assert(elftype >= ELF_T_FIRST && elftype <= ELF_T_LAST);
|
|
|
|
sh_off = s->s_offset;
|
|
assert(sh_off % _libelf_falign(elftype, ec) == 0);
|
|
|
|
/*
|
|
* If the section has a `rawdata' descriptor, and the section
|
|
* contents have not been modified, use its contents directly.
|
|
* The `s_rawoff' member contains the offset into the original
|
|
* file, while `s_offset' contains its new location in the
|
|
* destination.
|
|
*/
|
|
|
|
if (STAILQ_EMPTY(&s->s_data)) {
|
|
|
|
if ((d = elf_rawdata(s, NULL)) == NULL)
|
|
return ((off_t) -1);
|
|
|
|
STAILQ_FOREACH(d, &s->s_rawdata, d_next) {
|
|
if ((uint64_t) rc < sh_off + d->d_off)
|
|
(void) memset(nf + rc,
|
|
LIBELF_PRIVATE(fillchar), sh_off +
|
|
d->d_off - rc);
|
|
rc = sh_off + d->d_off;
|
|
|
|
assert(d->d_buf != NULL);
|
|
assert(d->d_type == ELF_T_BYTE);
|
|
assert(d->d_version == e->e_version);
|
|
|
|
(void) memcpy(nf + rc,
|
|
e->e_rawfile + s->s_rawoff + d->d_off, d->d_size);
|
|
|
|
rc += d->d_size;
|
|
}
|
|
|
|
return (rc);
|
|
}
|
|
|
|
/*
|
|
* Iterate over the set of data descriptors for this section.
|
|
* The prior call to _libelf_resync_elf() would have setup the
|
|
* descriptors for this step.
|
|
*/
|
|
|
|
dst.d_version = e->e_version;
|
|
|
|
STAILQ_FOREACH(d, &s->s_data, d_next) {
|
|
|
|
msz = _libelf_msize(d->d_type, ec, e->e_version);
|
|
|
|
if ((uint64_t) rc < sh_off + d->d_off)
|
|
(void) memset(nf + rc,
|
|
LIBELF_PRIVATE(fillchar), sh_off + d->d_off - rc);
|
|
|
|
rc = sh_off + d->d_off;
|
|
|
|
assert(d->d_buf != NULL);
|
|
assert(d->d_version == e->e_version);
|
|
assert(d->d_size % msz == 0);
|
|
|
|
nobjects = d->d_size / msz;
|
|
|
|
fsz = _libelf_fsize(d->d_type, ec, e->e_version, nobjects);
|
|
|
|
dst.d_buf = nf + rc;
|
|
dst.d_size = fsz;
|
|
|
|
if (_libelf_xlate(&dst, d, e->e_byteorder, ec, ELF_TOFILE) ==
|
|
NULL)
|
|
return ((off_t) -1);
|
|
|
|
rc += fsz;
|
|
}
|
|
|
|
return ((off_t) rc);
|
|
}
|
|
|
|
/*
|
|
* Write out the file image.
|
|
*
|
|
* The original file could have been mapped in with an ELF_C_RDWR
|
|
* command and the application could have added new content or
|
|
* re-arranged its sections before calling elf_update(). Consequently
|
|
* its not safe to work `in place' on the original file. So we
|
|
* malloc() the required space for the updated ELF object and build
|
|
* the object there and write it out to the underlying file at the
|
|
* end. Note that the application may have opened the underlying file
|
|
* in ELF_C_RDWR and only retrieved/modified a few sections. We take
|
|
* care to avoid translating file sections unnecessarily.
|
|
*
|
|
* Gaps in the coverage of the file by the file's sections will be
|
|
* filled with the fill character set by elf_fill(3).
|
|
*/
|
|
|
|
static off_t
|
|
_libelf_write_elf(Elf *e, off_t newsize)
|
|
{
|
|
int ec;
|
|
off_t maxrc, rc;
|
|
size_t fsz, msz, phnum, shnum;
|
|
uint64_t phoff, shoff;
|
|
void *ehdr;
|
|
char *newfile;
|
|
Elf_Data dst, src;
|
|
Elf_Scn *scn, *tscn;
|
|
Elf32_Ehdr *eh32;
|
|
Elf64_Ehdr *eh64;
|
|
|
|
assert(e->e_kind == ELF_K_ELF);
|
|
assert(e->e_cmd != ELF_C_READ);
|
|
assert(e->e_fd >= 0);
|
|
|
|
if ((newfile = malloc((size_t) newsize)) == NULL) {
|
|
LIBELF_SET_ERROR(RESOURCE, errno);
|
|
return ((off_t) -1);
|
|
}
|
|
|
|
ec = e->e_class;
|
|
|
|
ehdr = _libelf_ehdr(e, ec, 0);
|
|
assert(ehdr != NULL);
|
|
|
|
phnum = e->e_u.e_elf.e_nphdr;
|
|
|
|
if (ec == ELFCLASS32) {
|
|
eh32 = (Elf32_Ehdr *) ehdr;
|
|
|
|
phoff = (uint64_t) eh32->e_phoff;
|
|
shnum = eh32->e_shnum;
|
|
shoff = (uint64_t) eh32->e_shoff;
|
|
} else {
|
|
eh64 = (Elf64_Ehdr *) ehdr;
|
|
|
|
phoff = eh64->e_phoff;
|
|
shnum = eh64->e_shnum;
|
|
shoff = eh64->e_shoff;
|
|
}
|
|
|
|
fsz = _libelf_fsize(ELF_T_EHDR, ec, e->e_version, (size_t) 1);
|
|
msz = _libelf_msize(ELF_T_EHDR, ec, e->e_version);
|
|
|
|
(void) memset(&dst, 0, sizeof(dst));
|
|
(void) memset(&src, 0, sizeof(src));
|
|
|
|
src.d_buf = ehdr;
|
|
src.d_size = msz;
|
|
src.d_type = ELF_T_EHDR;
|
|
src.d_version = dst.d_version = e->e_version;
|
|
|
|
rc = 0;
|
|
|
|
dst.d_buf = newfile + rc;
|
|
dst.d_size = fsz;
|
|
|
|
if (_libelf_xlate(&dst, &src, e->e_byteorder, ec, ELF_TOFILE) ==
|
|
NULL)
|
|
goto error;
|
|
|
|
rc += fsz;
|
|
|
|
/*
|
|
* Write the program header table if present.
|
|
*/
|
|
|
|
if (phnum != 0 && phoff != 0) {
|
|
assert((unsigned) rc <= phoff);
|
|
|
|
fsz = _libelf_fsize(ELF_T_PHDR, ec, e->e_version, phnum);
|
|
|
|
assert(phoff % _libelf_falign(ELF_T_PHDR, ec) == 0);
|
|
assert(fsz > 0);
|
|
|
|
src.d_buf = _libelf_getphdr(e, ec);
|
|
src.d_version = dst.d_version = e->e_version;
|
|
src.d_type = ELF_T_PHDR;
|
|
src.d_size = phnum * _libelf_msize(ELF_T_PHDR, ec,
|
|
e->e_version);
|
|
|
|
dst.d_size = fsz;
|
|
|
|
if ((uint64_t) rc < phoff)
|
|
(void) memset(newfile + rc,
|
|
LIBELF_PRIVATE(fillchar), phoff - rc);
|
|
|
|
dst.d_buf = newfile + rc;
|
|
|
|
if (_libelf_xlate(&dst, &src, e->e_byteorder, ec, ELF_TOFILE) ==
|
|
NULL)
|
|
goto error;
|
|
|
|
rc = phoff + fsz;
|
|
}
|
|
|
|
/*
|
|
* Write out individual sections.
|
|
*/
|
|
|
|
STAILQ_FOREACH(scn, &e->e_u.e_elf.e_scn, s_next)
|
|
if ((rc = _libelf_write_scn(e, newfile, scn, rc)) < 0)
|
|
goto error;
|
|
|
|
/*
|
|
* Write out the section header table, if required. Note that
|
|
* if flag ELF_F_LAYOUT has been set the section header table
|
|
* could reside in between byte ranges mapped by section
|
|
* descriptors.
|
|
*/
|
|
if (shnum != 0 && shoff != 0) {
|
|
if ((uint64_t) rc < shoff)
|
|
(void) memset(newfile + rc,
|
|
LIBELF_PRIVATE(fillchar), shoff - rc);
|
|
|
|
maxrc = rc;
|
|
rc = shoff;
|
|
|
|
assert(rc % _libelf_falign(ELF_T_SHDR, ec) == 0);
|
|
|
|
src.d_type = ELF_T_SHDR;
|
|
src.d_size = _libelf_msize(ELF_T_SHDR, ec, e->e_version);
|
|
src.d_version = dst.d_version = e->e_version;
|
|
|
|
fsz = _libelf_fsize(ELF_T_SHDR, ec, e->e_version, (size_t) 1);
|
|
|
|
STAILQ_FOREACH(scn, &e->e_u.e_elf.e_scn, s_next) {
|
|
if (ec == ELFCLASS32)
|
|
src.d_buf = &scn->s_shdr.s_shdr32;
|
|
else
|
|
src.d_buf = &scn->s_shdr.s_shdr64;
|
|
|
|
dst.d_size = fsz;
|
|
dst.d_buf = newfile + rc + scn->s_ndx * fsz;
|
|
|
|
if (_libelf_xlate(&dst, &src, e->e_byteorder, ec,
|
|
ELF_TOFILE) != &dst)
|
|
goto error;
|
|
}
|
|
|
|
rc += e->e_u.e_elf.e_nscn * fsz;
|
|
if (maxrc > rc)
|
|
rc = maxrc;
|
|
}
|
|
|
|
assert(rc == newsize);
|
|
|
|
/*
|
|
* Write out the constructed contents and remap the file in
|
|
* read-only.
|
|
*/
|
|
|
|
if (e->e_rawfile && munmap(e->e_rawfile, e->e_rawsize) < 0) {
|
|
LIBELF_SET_ERROR(IO, errno);
|
|
goto error;
|
|
}
|
|
|
|
if (write(e->e_fd, newfile, (size_t) newsize) != newsize ||
|
|
lseek(e->e_fd, (off_t) 0, SEEK_SET) < 0) {
|
|
LIBELF_SET_ERROR(IO, errno);
|
|
goto error;
|
|
}
|
|
|
|
if (e->e_cmd != ELF_C_WRITE) {
|
|
if ((e->e_rawfile = mmap(NULL, (size_t) newsize, PROT_READ,
|
|
MAP_PRIVATE, e->e_fd, (off_t) 0)) == MAP_FAILED) {
|
|
LIBELF_SET_ERROR(IO, errno);
|
|
goto error;
|
|
}
|
|
e->e_rawsize = newsize;
|
|
}
|
|
|
|
/*
|
|
* Reset flags, remove existing section descriptors and
|
|
* {E,P}HDR pointers so that a subsequent elf_get{e,p}hdr()
|
|
* and elf_getscn() will function correctly.
|
|
*/
|
|
|
|
e->e_flags &= ~ELF_F_DIRTY;
|
|
|
|
STAILQ_FOREACH_SAFE(scn, &e->e_u.e_elf.e_scn, s_next, tscn)
|
|
_libelf_release_scn(scn);
|
|
|
|
if (ec == ELFCLASS32) {
|
|
free(e->e_u.e_elf.e_ehdr.e_ehdr32);
|
|
if (e->e_u.e_elf.e_phdr.e_phdr32)
|
|
free(e->e_u.e_elf.e_phdr.e_phdr32);
|
|
|
|
e->e_u.e_elf.e_ehdr.e_ehdr32 = NULL;
|
|
e->e_u.e_elf.e_phdr.e_phdr32 = NULL;
|
|
} else {
|
|
free(e->e_u.e_elf.e_ehdr.e_ehdr64);
|
|
if (e->e_u.e_elf.e_phdr.e_phdr64)
|
|
free(e->e_u.e_elf.e_phdr.e_phdr64);
|
|
|
|
e->e_u.e_elf.e_ehdr.e_ehdr64 = NULL;
|
|
e->e_u.e_elf.e_phdr.e_phdr64 = NULL;
|
|
}
|
|
|
|
free(newfile);
|
|
|
|
return (rc);
|
|
|
|
error:
|
|
free(newfile);
|
|
|
|
return ((off_t) -1);
|
|
}
|
|
|
|
off_t
|
|
elf_update(Elf *e, Elf_Cmd c)
|
|
{
|
|
int ec;
|
|
off_t rc;
|
|
|
|
rc = (off_t) -1;
|
|
|
|
if (e == NULL || e->e_kind != ELF_K_ELF ||
|
|
(c != ELF_C_NULL && c != ELF_C_WRITE)) {
|
|
LIBELF_SET_ERROR(ARGUMENT, 0);
|
|
return (rc);
|
|
}
|
|
|
|
if ((ec = e->e_class) != ELFCLASS32 && ec != ELFCLASS64) {
|
|
LIBELF_SET_ERROR(CLASS, 0);
|
|
return (rc);
|
|
}
|
|
|
|
if (e->e_version == EV_NONE)
|
|
e->e_version = EV_CURRENT;
|
|
|
|
if (c == ELF_C_WRITE && e->e_cmd == ELF_C_READ) {
|
|
LIBELF_SET_ERROR(MODE, 0);
|
|
return (rc);
|
|
}
|
|
|
|
if ((rc = _libelf_resync_elf(e)) < 0)
|
|
return (rc);
|
|
|
|
if (c == ELF_C_NULL)
|
|
return (rc);
|
|
|
|
if (e->e_cmd == ELF_C_READ) {
|
|
/*
|
|
* This descriptor was opened in read-only mode or by
|
|
* elf_memory().
|
|
*/
|
|
if (e->e_fd)
|
|
LIBELF_SET_ERROR(MODE, 0);
|
|
else
|
|
LIBELF_SET_ERROR(ARGUMENT, 0);
|
|
return ((off_t) -1);
|
|
}
|
|
|
|
if (e->e_fd < 0) {
|
|
LIBELF_SET_ERROR(SEQUENCE, 0);
|
|
return ((off_t) -1);
|
|
}
|
|
|
|
return (_libelf_write_elf(e, rc));
|
|
}
|