| /*- | |
| * Copyright (c) 2006 Joseph Koshy | |
| * 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. | |
| */ | |
| #include <sys/mman.h> | |
| #include <sys/param.h> | |
| #ifdef __sun | |
| #include <sys/sysmacros.h> | |
| #endif | |
| #include <assert.h> | |
| #include <errno.h> | |
| #include "gelf.h" | |
| #include "libelf.h" | |
| #include <stdlib.h> | |
| #include <string.h> | |
| #include <unistd.h> | |
| #include "_libelf.h" | |
| /* | |
| * Update the internal data structures associated with an ELF object. | |
| * Returns the size in bytes the ELF object would occupy in its file | |
| * representation. | |
| * | |
| * After a successful call to this function, the following structures | |
| * are updated: | |
| * | |
| * - The ELF header is updated. | |
| * - All sections are sorted in order of ascending addresses and their | |
| * section header table entries updated. An error is signalled | |
| * if an overlap was detected among sections. | |
| * - All data descriptors associated with a section are sorted in order | |
| * of ascending addresses. Overlaps, if detected, are signalled as | |
| * errors. Other sanity checks for alignments, section types etc. are | |
| * made. | |
| * | |
| * After a resync_elf() successfully returns, the ELF descriptor is | |
| * ready for being handed over to _libelf_write_elf(). | |
| * | |
| * File alignments: | |
| * PHDR - Addr | |
| * SHDR - Addr | |
| * | |
| * XXX: how do we handle 'flags'. | |
| */ | |
| /* | |
| * Compute the extents of a section, by looking at the. | |
| */ | |
| static int | |
| _libelf_compute_section_extents(Elf *e, Elf_Scn *s, off_t *rc) | |
| { | |
| int ec; | |
| Elf_Data *d, *td; | |
| unsigned int elftype; | |
| uint32_t sh_type; | |
| uint64_t d_align; | |
| uint64_t sh_align, sh_entsize, sh_offset, sh_size; | |
| uint64_t scn_size, scn_alignment; | |
| /* | |
| * We need to recompute library private data structures if one | |
| * or more of the following is true: | |
| * - The underlying Shdr structure has been marked `dirty'. Significant | |
| * fields include: `sh_offset', `sh_type', `sh_size', `sh_addralign'. | |
| * - The Elf_Data structures part of this section have been marked | |
| * `dirty'. Affected members include `d_align', `d_offset', `d_type', | |
| * and `d_size'. | |
| * - The section as a whole is `dirty', e.g., it has been allocated | |
| * using elf_newscn(), or if a new Elf_Data structure was added using | |
| * elf_newdata(). | |
| * | |
| * Each of these conditions would result in the ELF_F_DIRTY bit being | |
| * set on the section descriptor's `s_flags' field. | |
| */ | |
| ec = e->e_class; | |
| if (ec == ELFCLASS32) { | |
| sh_type = s->s_shdr.s_shdr32.sh_type; | |
| sh_align = (uint64_t) s->s_shdr.s_shdr32.sh_addralign; | |
| sh_entsize = (uint64_t) s->s_shdr.s_shdr32.sh_entsize; | |
| sh_offset = (uint64_t) s->s_shdr.s_shdr32.sh_offset; | |
| sh_size = (uint64_t) s->s_shdr.s_shdr32.sh_size; | |
| } else { | |
| sh_type = s->s_shdr.s_shdr64.sh_type; | |
| sh_align = s->s_shdr.s_shdr64.sh_addralign; | |
| sh_entsize = s->s_shdr.s_shdr64.sh_entsize; | |
| sh_offset = s->s_shdr.s_shdr64.sh_offset; | |
| sh_size = s->s_shdr.s_shdr64.sh_size; | |
| } | |
| if (sh_type == SHT_NULL || sh_type == SHT_NOBITS) | |
| return (1); | |
| if ((s->s_flags & ELF_F_DIRTY) == 0) { | |
| if ((size_t) *rc < sh_offset + sh_size) | |
| *rc = sh_offset + sh_size; | |
| return (1); | |
| } | |
| elftype = _libelf_xlate_shtype(sh_type); | |
| if (elftype > ELF_T_LAST) { | |
| LIBELF_SET_ERROR(SECTION, 0); | |
| return (0); | |
| } | |
| /* | |
| * Compute the extent of the data descriptors associated with | |
| * this section. | |
| */ | |
| scn_alignment = 0; | |
| if (sh_align == 0) | |
| sh_align = _libelf_falign(elftype, ec); | |
| /* Compute the section alignment. */ | |
| STAILQ_FOREACH(d, &s->s_data, d_next) { | |
| if (d->d_type != elftype) { | |
| LIBELF_SET_ERROR(DATA, 0); | |
| return (0); | |
| } | |
| if (d->d_version != e->e_version) { | |
| LIBELF_SET_ERROR(VERSION, 0); | |
| return (0); | |
| } | |
| if ((d_align = d->d_align) % sh_align) { | |
| LIBELF_SET_ERROR(LAYOUT, 0); | |
| return (0); | |
| } | |
| if (d_align == 0 || (d_align & (d_align - 1))) { | |
| LIBELF_SET_ERROR(DATA, 0); | |
| return (0); | |
| } | |
| if (d_align > scn_alignment) | |
| scn_alignment = d_align; | |
| } | |
| scn_size = 0L; | |
| STAILQ_FOREACH_SAFE(d, &s->s_data, d_next, td) { | |
| if (e->e_flags & ELF_F_LAYOUT) { | |
| if ((uint64_t) d->d_off + d->d_size > scn_size) | |
| scn_size = d->d_off + d->d_size; | |
| } else { | |
| scn_size = roundup(scn_size, scn_alignment); | |
| d->d_off = scn_size; | |
| scn_size += d->d_size; | |
| } | |
| } | |
| /* | |
| * If the application is requesting full control over the layout | |
| * of the section, check its values for sanity. | |
| */ | |
| if (e->e_flags & ELF_F_LAYOUT) { | |
| if (scn_alignment > sh_align || sh_offset % sh_align || | |
| sh_size < scn_size) { | |
| LIBELF_SET_ERROR(LAYOUT, 0); | |
| return (0); | |
| } | |
| } else { | |
| /* | |
| * Otherwise compute the values in the section header. | |
| */ | |
| if (scn_alignment > sh_align) | |
| sh_align = scn_alignment; | |
| /* | |
| * If the section entry size is zero, try and fill in an | |
| * appropriate entry size. Per the elf(5) manual page | |
| * sections without fixed-size entries should have their | |
| * 'sh_entsize' field set to zero. | |
| */ | |
| if (sh_entsize == 0 && | |
| (sh_entsize = _libelf_fsize(elftype, ec, e->e_version, | |
| (size_t) 1)) == 1) | |
| sh_entsize = 0; | |
| sh_size = scn_size; | |
| sh_offset = roundup(*rc, sh_align); | |
| if (ec == ELFCLASS32) { | |
| s->s_shdr.s_shdr32.sh_addralign = (uint32_t) sh_align; | |
| s->s_shdr.s_shdr32.sh_entsize = (uint32_t) sh_entsize; | |
| s->s_shdr.s_shdr32.sh_offset = (uint32_t) sh_offset; | |
| s->s_shdr.s_shdr32.sh_size = (uint32_t) sh_size; | |
| } else { | |
| s->s_shdr.s_shdr64.sh_addralign = sh_align; | |
| s->s_shdr.s_shdr64.sh_entsize = sh_entsize; | |
| s->s_shdr.s_shdr64.sh_offset = sh_offset; | |
| s->s_shdr.s_shdr64.sh_size = sh_size; | |
| } | |
| } | |
| if ((size_t) *rc < sh_offset + sh_size) | |
| *rc = sh_offset + sh_size; | |
| s->s_size = sh_size; | |
| s->s_offset = sh_offset; | |
| return (1); | |
| } | |
| /* | |
| * Insert a section in ascending order in the list | |
| */ | |
| static int | |
| _libelf_insert_section(Elf *e, Elf_Scn *s) | |
| { | |
| Elf_Scn *t, *prevt; | |
| uint64_t smax, smin, tmax, tmin; | |
| smin = s->s_offset; | |
| smax = smin + s->s_size; | |
| prevt = NULL; | |
| STAILQ_FOREACH(t, &e->e_u.e_elf.e_scn, s_next) { | |
| tmin = t->s_offset; | |
| tmax = tmin + t->s_size; | |
| /* check if there is an overlap */ | |
| if (tmax < smin) { | |
| prevt = t; | |
| continue; | |
| } else if (smax < tmin) | |
| break; | |
| else { | |
| LIBELF_SET_ERROR(LAYOUT, 0); | |
| return (0); | |
| } | |
| } | |
| if (prevt) | |
| STAILQ_INSERT_AFTER(&e->e_u.e_elf.e_scn, prevt, s, s_next); | |
| else | |
| STAILQ_INSERT_HEAD(&e->e_u.e_elf.e_scn, s, s_next); | |
| return (1); | |
| } | |
| static off_t | |
| _libelf_resync_sections(Elf *e, off_t rc) | |
| { | |
| int ec; | |
| off_t nrc; | |
| size_t sh_type; | |
| Elf_Scn *s, *ts; | |
| ec = e->e_class; | |
| /* | |
| * Make a pass through sections, computing the extent of each | |
| * section. Order in increasing order of addresses. | |
| */ | |
| nrc = rc; | |
| STAILQ_FOREACH(s, &e->e_u.e_elf.e_scn, s_next) | |
| if (_libelf_compute_section_extents(e, s, &nrc) == 0) | |
| return ((off_t) -1); | |
| STAILQ_FOREACH_SAFE(s, &e->e_u.e_elf.e_scn, s_next, ts) { | |
| if (ec == ELFCLASS32) | |
| sh_type = s->s_shdr.s_shdr32.sh_type; | |
| else | |
| sh_type = s->s_shdr.s_shdr64.sh_type; | |
| /* XXX Do we need the 'size' field of an SHT_NOBITS section */ | |
| if (sh_type == SHT_NOBITS || sh_type == SHT_NULL) | |
| continue; | |
| if (s->s_offset < (uint64_t) rc) { | |
| if (s->s_offset + s->s_size < (uint64_t) rc) { | |
| /* | |
| * Try insert this section in the | |
| * correct place in the list, | |
| * detecting overlaps if any. | |
| */ | |
| STAILQ_REMOVE(&e->e_u.e_elf.e_scn, s, _Elf_Scn, | |
| s_next); | |
| if (_libelf_insert_section(e, s) == 0) | |
| return ((off_t) -1); | |
| } else { | |
| LIBELF_SET_ERROR(LAYOUT, 0); | |
| return ((off_t) -1); | |
| } | |
| } else | |
| rc = s->s_offset + s->s_size; | |
| } | |
| assert(nrc == rc); | |
| return (rc); | |
| } | |
| static off_t | |
| _libelf_resync_elf(Elf *e) | |
| { | |
| int ec, eh_class, eh_type; | |
| unsigned int eh_byteorder, eh_version; | |
| size_t align, fsz; | |
| size_t phnum, shnum; | |
| off_t rc, phoff, shoff; | |
| void *ehdr; | |
| Elf32_Ehdr *eh32; | |
| Elf64_Ehdr *eh64; | |
| rc = 0; | |
| ec = e->e_class; | |
| assert(ec == ELFCLASS32 || ec == ELFCLASS64); | |
| /* | |
| * Prepare the EHDR. | |
| */ | |
| if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL) | |
| return ((off_t) -1); | |
| eh32 = ehdr; | |
| eh64 = ehdr; | |
| if (ec == ELFCLASS32) { | |
| eh_byteorder = eh32->e_ident[EI_DATA]; | |
| eh_class = eh32->e_ident[EI_CLASS]; | |
| phoff = (uint64_t) eh32->e_phoff; | |
| shoff = (uint64_t) eh32->e_shoff; | |
| eh_type = eh32->e_type; | |
| eh_version = eh32->e_version; | |
| } else { | |
| eh_byteorder = eh64->e_ident[EI_DATA]; | |
| eh_class = eh64->e_ident[EI_CLASS]; | |
| phoff = eh64->e_phoff; | |
| shoff = eh64->e_shoff; | |
| eh_type = eh64->e_type; | |
| eh_version = eh64->e_version; | |
| } | |
| if (eh_version == EV_NONE) | |
| eh_version = EV_CURRENT; | |
| if (eh_version != e->e_version) { /* always EV_CURRENT */ | |
| LIBELF_SET_ERROR(VERSION, 0); | |
| return ((off_t) -1); | |
| } | |
| if (eh_class != e->e_class) { | |
| LIBELF_SET_ERROR(CLASS, 0); | |
| return ((off_t) -1); | |
| } | |
| if (e->e_cmd != ELF_C_WRITE && eh_byteorder != e->e_byteorder) { | |
| LIBELF_SET_ERROR(HEADER, 0); | |
| return ((off_t) -1); | |
| } | |
| shnum = e->e_u.e_elf.e_nscn; | |
| phnum = e->e_u.e_elf.e_nphdr; | |
| e->e_byteorder = eh_byteorder; | |
| #define INITIALIZE_EHDR(E,EC,V) do { \ | |
| (E)->e_ident[EI_MAG0] = ELFMAG0; \ | |
| (E)->e_ident[EI_MAG1] = ELFMAG1; \ | |
| (E)->e_ident[EI_MAG2] = ELFMAG2; \ | |
| (E)->e_ident[EI_MAG3] = ELFMAG3; \ | |
| (E)->e_ident[EI_CLASS] = (EC); \ | |
| (E)->e_ident[EI_VERSION] = (V); \ | |
| (E)->e_ehsize = _libelf_fsize(ELF_T_EHDR, (EC), (V), \ | |
| (size_t) 1); \ | |
| (E)->e_phentsize = _libelf_fsize(ELF_T_PHDR, (EC), (V), \ | |
| (size_t) 1); \ | |
| (E)->e_shentsize = _libelf_fsize(ELF_T_SHDR, (EC), (V), \ | |
| (size_t) 1); \ | |
| } while (0) | |
| if (ec == ELFCLASS32) | |
| INITIALIZE_EHDR(eh32, ec, eh_version); | |
| else | |
| INITIALIZE_EHDR(eh64, ec, eh_version); | |
| (void) elf_flagehdr(e, ELF_C_SET, ELF_F_DIRTY); | |
| rc += _libelf_fsize(ELF_T_EHDR, ec, eh_version, (size_t) 1); | |
| /* | |
| * Compute the layout the program header table, if one is | |
| * present. The program header table needs to be aligned to a | |
| * `natural' boundary. | |
| */ | |
| if (phnum) { | |
| 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 ((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 (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 (rc > shoff) { | |
| LIBELF_SET_ERROR(HEADER, 0); | |
| return ((off_t) -1); | |
| } | |
| if (shoff % align) { | |
| LIBELF_SET_ERROR(LAYOUT, 0); | |
| return ((off_t) -1); | |
| } | |
| } else | |
| shoff = roundup(rc, align); | |
| 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; | |
| int elftype; | |
| Elf_Data *d, dst; | |
| if ((ec = e->e_class) == ELFCLASS32) | |
| sh_type = s->s_shdr.s_shdr32.sh_type; | |
| else | |
| sh_type = s->s_shdr.s_shdr64.sh_type; | |
| /* | |
| * Ignore sections that do not allocate space in the file. | |
| */ | |
| if (sh_type == SHT_NOBITS || sh_type == SHT_NULL) | |
| return (rc); | |
| elftype = _libelf_xlate_shtype(sh_type); | |
| assert(elftype >= ELF_T_FIRST && elftype <= ELF_T_LAST); | |
| msz = _libelf_msize(elftype, ec, e->e_version); | |
| 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) { | |
| 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_Type) elftype); | |
| assert(d->d_version == e->e_version); | |
| assert(d->d_size % msz == 0); | |
| nobjects = d->d_size / msz; | |
| fsz = _libelf_fsize(elftype, 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 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_version = dst.d_version = e->e_version; | |
| src.d_type = ELF_T_PHDR; | |
| if (ec == ELFCLASS32) | |
| src.d_buf = e->e_u.e_elf.e_phdr.e_phdr32; | |
| else | |
| src.d_buf = e->e_u.e_elf.e_phdr.e_phdr64; | |
| 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. | |
| */ | |
| if (shnum != 0 && shoff != 0) { | |
| assert((unsigned) rc <= shoff); | |
| if ((uint64_t) rc < shoff) | |
| (void) memset(newfile + rc, | |
| LIBELF_PRIVATE(fillchar), shoff - 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; | |
| if (_libelf_xlate(&dst, &src, e->e_byteorder, ec, | |
| ELF_TOFILE) != &dst) | |
| goto error; | |
| rc += fsz; | |
| } | |
| } | |
| /* | |
| */ | |
| 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; | |
| } | |
| return (rc); | |
| error: | |
| if (newfile) | |
| 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)); | |
| } |