diff options
Diffstat (limited to 'linkers/elftoolchain/libelf/elf_update.c')
| -rw-r--r-- | linkers/elftoolchain/libelf/elf_update.c | 1184 |
1 files changed, 0 insertions, 1184 deletions
diff --git a/linkers/elftoolchain/libelf/elf_update.c b/linkers/elftoolchain/libelf/elf_update.c deleted file mode 100644 index 9806131..0000000 --- a/linkers/elftoolchain/libelf/elf_update.c +++ /dev/null @@ -1,1184 +0,0 @@ -/*- - * Copyright (c) 2006-2011 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/stat.h> - -#include <assert.h> -#include <errno.h> -#include <gelf.h> -#include <libelf.h> -#include <stdlib.h> -#include <string.h> -#include <unistd.h> - -#include "_libelf.h" - -LIBELF_VCSID("$Id: elf_update.c 1922 2011-09-23 08:04:33Z jkoshy $"); - -/* - * Layout strategy: - * - * - Case 1: ELF_F_LAYOUT is asserted - * In this case the application has full control over where the - * section header table, program header table, and section data - * will reside. The library only perform error checks. - * - * - Case 2: ELF_F_LAYOUT is not asserted - * - * The library will do the object layout using the following - * ordering: - * - The executable header is placed first, are required by the - * ELF specification. - * - The program header table is placed immediately following the - * executable header. - * - Section data, if any, is placed after the program header - * table, aligned appropriately. - * - The section header table, if needed, is placed last. - * - * There are two sub-cases to be taken care of: - * - * - Case 2a: e->e_cmd == ELF_C_READ or ELF_C_RDWR - * - * In this sub-case, the underlying ELF object may already have - * content in it, which the application may have modified. The - * library will retrieve content from the existing object as - * needed. - * - * - Case 2b: e->e_cmd == ELF_C_WRITE - * - * The ELF object is being created afresh in this sub-case; - * there is no pre-existing content in the underlying ELF - * object. - */ - -/* - * The types of extents in an ELF object. - */ -enum elf_extent { - ELF_EXTENT_EHDR, - ELF_EXTENT_PHDR, - ELF_EXTENT_SECTION, - ELF_EXTENT_SHDR -}; - -/* - * A extent descriptor, used when laying out an ELF object. - */ -struct _Elf_Extent { - SLIST_ENTRY(_Elf_Extent) ex_next; - uint64_t ex_start; /* Start of the region. */ - uint64_t ex_size; /* The size of the region. */ - enum elf_extent ex_type; /* Type of region. */ - void *ex_desc; /* Associated descriptor. */ -}; - -SLIST_HEAD(_Elf_Extent_List, _Elf_Extent); - -/* - * Compute the extents of a section, by looking at the data - * descriptors associated with it. The function returns 1 - * if successful, or zero if an error was detected. - */ -static int -_libelf_compute_section_extents(Elf *e, Elf_Scn *s, off_t rc) -{ - int ec; - size_t fsz, msz; - Elf_Data *d; - Elf32_Shdr *shdr32; - Elf64_Shdr *shdr64; - uint32_t sh_type; - uint64_t d_align; - unsigned int elftype; - uint64_t scn_size, scn_alignment; - uint64_t sh_align, sh_entsize, sh_offset, sh_size; - - ec = e->e_class; - - shdr32 = &s->s_shdr.s_shdr32; - shdr64 = &s->s_shdr.s_shdr64; - if (ec == ELFCLASS32) { - sh_type = shdr32->sh_type; - sh_align = (uint64_t) shdr32->sh_addralign; - sh_entsize = (uint64_t) shdr32->sh_entsize; - sh_offset = (uint64_t) shdr32->sh_offset; - sh_size = (uint64_t) shdr32->sh_size; - } else { - sh_type = shdr64->sh_type; - sh_align = shdr64->sh_addralign; - sh_entsize = shdr64->sh_entsize; - sh_offset = shdr64->sh_offset; - sh_size = shdr64->sh_size; - } - - assert(sh_type != SHT_NULL && sh_type != SHT_NOBITS); - - elftype = _libelf_xlate_shtype(sh_type); - if (elftype > ELF_T_LAST) { - LIBELF_SET_ERROR(SECTION, 0); - return (0); - } - - if (sh_align == 0) - sh_align = _libelf_falign(elftype, ec); - - /* - * Compute the section's size and alignment using the data - * descriptors associated with the section. - */ - if (STAILQ_EMPTY(&s->s_data)) { - /* - * The section's content (if any) has not been read in - * yet. If section is not dirty marked dirty, we can - * reuse the values in the 'sh_size' and 'sh_offset' - * fields of the section header. - */ - if ((s->s_flags & ELF_F_DIRTY) == 0) { - /* - * If the library is doing the layout, then we - * compute the new start offset for the - * section based on the current offset and the - * section's alignment needs. - * - * If the application is doing the layout, we - * can use the value in the 'sh_offset' field - * in the section header directly. - */ - if (e->e_flags & ELF_F_LAYOUT) - goto updatedescriptor; - else - goto computeoffset; - } - - /* - * Otherwise, we need to bring in the section's data - * from the underlying ELF object. - */ - if (e->e_cmd != ELF_C_WRITE && elf_getdata(s, NULL) == NULL) - return (0); - } - - /* - * Loop through the section's data descriptors. - */ - scn_size = 0L; - scn_alignment = 0; - STAILQ_FOREACH(d, &s->s_data, d_next) { - - /* - * The data buffer's type is known. - */ - if (d->d_type >= ELF_T_NUM) { - LIBELF_SET_ERROR(DATA, 0); - return (0); - } - - /* - * The data buffer's version is supported. - */ - if (d->d_version != e->e_version) { - LIBELF_SET_ERROR(VERSION, 0); - return (0); - } - - /* - * The buffer's alignment is non-zero and a power of - * two. - */ - if ((d_align = d->d_align) == 0 || - (d_align & (d_align - 1))) { - LIBELF_SET_ERROR(DATA, 0); - return (0); - } - - /* - * The buffer's size should be a multiple of the - * memory size of the underlying type. - */ - msz = _libelf_msize(d->d_type, ec, e->e_version); - if (d->d_size % msz) { - LIBELF_SET_ERROR(DATA, 0); - return (0); - } - - /* - * If the application is controlling layout, then the - * d_offset field should be compatible with the - * buffer's specified alignment. - */ - if ((e->e_flags & ELF_F_LAYOUT) && - (d->d_off & (d_align - 1))) { - LIBELF_SET_ERROR(LAYOUT, 0); - return (0); - } - - /* - * Compute the section's size. - */ - 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 = roundup2(scn_size, d->d_align); - d->d_off = scn_size; - fsz = _libelf_fsize(d->d_type, ec, d->d_version, - d->d_size / msz); - scn_size += fsz; - } - - /* - * The section's alignment is the maximum alignment - * needed for its data buffers. - */ - if (d_align > scn_alignment) - scn_alignment = d_align; - } - - - /* - * If the application is requesting full control over the - * layout of the section, check the section's specified size, - * offsets and alignment 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); - } - goto updatedescriptor; - } - - /* - * Otherwise, compute the values in the section header. - * - * The section alignment is the maximum alignment for any of - * its contained data descriptors. - */ - 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; - -computeoffset: - /* - * Compute the new offset for the section based on - * the section's alignment needs. - */ - sh_offset = roundup(rc, sh_align); - - /* - * Update the section header. - */ - if (ec == ELFCLASS32) { - shdr32->sh_addralign = (uint32_t) sh_align; - shdr32->sh_entsize = (uint32_t) sh_entsize; - shdr32->sh_offset = (uint32_t) sh_offset; - shdr32->sh_size = (uint32_t) sh_size; - } else { - shdr64->sh_addralign = sh_align; - shdr64->sh_entsize = sh_entsize; - shdr64->sh_offset = sh_offset; - shdr64->sh_size = sh_size; - } - -updatedescriptor: - /* - * Update the section descriptor. - */ - s->s_size = sh_size; - s->s_offset = sh_offset; - - return (1); -} - -/* - * Free a list of extent descriptors. - */ - -static void -_libelf_release_extents(struct _Elf_Extent_List *extents) -{ - struct _Elf_Extent *ex; - - while ((ex = SLIST_FIRST(extents)) != NULL) { - SLIST_REMOVE_HEAD(extents, ex_next); - free(ex); - } -} - -/* - * Check if an extent 's' defined by [start..start+size) is free. - * This routine assumes that the given extent list is sorted in order - * of ascending extent offsets. - */ - -static int -_libelf_extent_is_unused(struct _Elf_Extent_List *extents, - const uint64_t start, const uint64_t size, struct _Elf_Extent **prevt) -{ - uint64_t tmax, tmin; - struct _Elf_Extent *t, *pt; - const uint64_t smax = start + size; - - /* First, look for overlaps with existing extents. */ - pt = NULL; - SLIST_FOREACH(t, extents, ex_next) { - tmin = t->ex_start; - tmax = tmin + t->ex_size; - - if (tmax <= start) { - /* - * 't' lies entirely before 's': ...| t |...| s |... - */ - pt = t; - continue; - } else if (smax <= tmin) { - /* - * 's' lies entirely before 't', and after 'pt': - * ...| pt |...| s |...| t |... - */ - assert(pt == NULL || - pt->ex_start + pt->ex_size <= start); - break; - } else - /* 's' and 't' overlap. */ - return (0); - } - - if (prevt) - *prevt = pt; - return (1); -} - -/* - * Insert an extent into the list of extents. - */ - -static int -_libelf_insert_extent(struct _Elf_Extent_List *extents, int type, - uint64_t start, uint64_t size, void *desc) -{ - struct _Elf_Extent *ex, *prevt; - - assert(type >= ELF_EXTENT_EHDR && type <= ELF_EXTENT_SHDR); - - prevt = NULL; - - /* - * If the requested range overlaps with an existing extent, - * signal an error. - */ - if (!_libelf_extent_is_unused(extents, start, size, &prevt)) { - LIBELF_SET_ERROR(LAYOUT, 0); - return (0); - } - - /* Allocate and fill in a new extent descriptor. */ - if ((ex = malloc(sizeof(struct _Elf_Extent))) == NULL) { - LIBELF_SET_ERROR(RESOURCE, errno); - return (0); - } - ex->ex_start = start; - ex->ex_size = size; - ex->ex_desc = desc; - ex->ex_type = type; - - /* Insert the region descriptor into the list. */ - if (prevt) - SLIST_INSERT_AFTER(prevt, ex, ex_next); - else - SLIST_INSERT_HEAD(extents, ex, ex_next); - return (1); -} - -/* - * Recompute section layout. - */ - -static off_t -_libelf_resync_sections(Elf *e, off_t rc, struct _Elf_Extent_List *extents) -{ - int ec; - Elf_Scn *s; - size_t sh_type; - - ec = e->e_class; - - /* - * Make a pass through sections, computing the extent of each - * section. - */ - STAILQ_FOREACH(s, &e->e_u.e_elf.e_scn, s_next) { - if (ec == ELFCLASS32) - sh_type = s->s_shdr.s_shdr32.sh_type; - else - sh_type = s->s_shdr.s_shdr64.sh_type; - - if (sh_type == SHT_NOBITS || sh_type == SHT_NULL) - continue; - - if (_libelf_compute_section_extents(e, s, rc) == 0) - return ((off_t) -1); - - if (s->s_size == 0) - continue; - - if (!_libelf_insert_extent(extents, ELF_EXTENT_SECTION, - s->s_offset, s->s_size, s)) - return ((off_t) -1); - - if ((size_t) rc < s->s_offset + s->s_size) - rc = s->s_offset + s->s_size; - } - - return (rc); -} - -/* - * Recompute the layout of the ELF object and update the internal data - * structures associated with the ELF descriptor. - * - * 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 extents in the ELF object are sorted in order of ascending - * addresses. Sections have their section header table entries - * updated. An error is signalled if an overlap was detected among - * extents. - * - Data descriptors associated with sections are checked for valid - * types, offsets and alignment. - * - * After a resync_elf() successfully returns, the ELF descriptor is - * ready for being handed over to _libelf_write_elf(). - */ - -static off_t -_libelf_resync_elf(Elf *e, struct _Elf_Extent_List *extents) -{ - 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, *phdr; - 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 = (phnum == 0) ? 0 : _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); - - if (!_libelf_insert_extent(extents, ELF_EXTENT_EHDR, 0, rc, ehdr)) - return ((off_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(LAYOUT, 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; - - phdr = _libelf_getphdr(e, ec); - - if (!_libelf_insert_extent(extents, ELF_EXTENT_PHDR, phoff, - fsz, phdr)) - return ((off_t) -1); - } 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_section_headers(e, ehdr) == 0) - return ((off_t) -1); - - if ((rc = _libelf_resync_sections(e, rc, extents)) < 0) - return ((off_t) -1); - - /* - * Compute the space taken up by the section header table, if - * one is needed. - * - * If ELF_F_LAYOUT has been 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 the library is responsible for laying out the object, - * the section header table is placed after section data. - */ - if (shnum) { - fsz = _libelf_fsize(ELF_T_SHDR, ec, eh_version, shnum); - 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 > (size_t) rc) - rc = shoff + fsz; - - if (!_libelf_insert_extent(extents, ELF_EXTENT_SHDR, shoff, - fsz, NULL)) - return ((off_t) -1); - } 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 an ELF section. - */ - -static size_t -_libelf_write_scn(Elf *e, char *nf, struct _Elf_Extent *ex) -{ - int ec; - size_t fsz, msz, nobjects, rc; - uint32_t sh_type; - uint64_t sh_off, sh_size; - int elftype; - Elf_Scn *s; - Elf_Data *d, dst; - - assert(ex->ex_type == ELF_EXTENT_SECTION); - - s = ex->ex_desc; - rc = ex->ex_start; - - 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 an ELF Executable Header. - */ - -static off_t -_libelf_write_ehdr(Elf *e, char *nf, struct _Elf_Extent *ex) -{ - int ec; - void *ehdr; - size_t fsz, msz; - Elf_Data dst, src; - - assert(ex->ex_type == ELF_EXTENT_EHDR); - assert(ex->ex_start == 0); /* Ehdr always comes first. */ - - ec = e->e_class; - - ehdr = _libelf_ehdr(e, ec, 0); - assert(ehdr != NULL); - - 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; - - dst.d_buf = nf; - dst.d_size = fsz; - - if (_libelf_xlate(&dst, &src, e->e_byteorder, ec, ELF_TOFILE) == - NULL) - return ((off_t) -1); - - return ((off_t) fsz); -} - -/* - * Write out an ELF program header table. - */ - -static off_t -_libelf_write_phdr(Elf *e, char *nf, struct _Elf_Extent *ex) -{ - int ec; - void *ehdr; - Elf32_Ehdr *eh32; - Elf64_Ehdr *eh64; - Elf_Data dst, src; - size_t fsz, phnum; - uint64_t phoff; - - assert(ex->ex_type == ELF_EXTENT_PHDR); - - ec = e->e_class; - ehdr = _libelf_ehdr(e, ec, 0); - phnum = e->e_u.e_elf.e_nphdr; - - assert(phnum > 0); - - if (ec == ELFCLASS32) { - eh32 = (Elf32_Ehdr *) ehdr; - phoff = (uint64_t) eh32->e_phoff; - } else { - eh64 = (Elf64_Ehdr *) ehdr; - phoff = eh64->e_phoff; - } - - assert(phoff > 0); - assert(ex->ex_start == phoff); - assert(phoff % _libelf_falign(ELF_T_PHDR, ec) == 0); - - (void) memset(&dst, 0, sizeof(dst)); - (void) memset(&src, 0, sizeof(src)); - - fsz = _libelf_fsize(ELF_T_PHDR, ec, e->e_version, phnum); - 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; - dst.d_buf = nf + ex->ex_start; - - if (_libelf_xlate(&dst, &src, e->e_byteorder, ec, ELF_TOFILE) == - NULL) - return ((off_t) -1); - - return (phoff + fsz); -} - -/* - * Write out an ELF section header table. - */ - -static off_t -_libelf_write_shdr(Elf *e, char *nf, struct _Elf_Extent *ex) -{ - int ec; - void *ehdr; - Elf_Scn *scn; - uint64_t shoff; - Elf32_Ehdr *eh32; - Elf64_Ehdr *eh64; - size_t fsz, nscn; - Elf_Data dst, src; - - assert(ex->ex_type == ELF_EXTENT_SHDR); - - ec = e->e_class; - ehdr = _libelf_ehdr(e, ec, 0); - nscn = e->e_u.e_elf.e_nscn; - - if (ec == ELFCLASS32) { - eh32 = (Elf32_Ehdr *) ehdr; - shoff = (uint64_t) eh32->e_shoff; - } else { - eh64 = (Elf64_Ehdr *) ehdr; - shoff = eh64->e_shoff; - } - - assert(nscn > 0); - assert(shoff % _libelf_falign(ELF_T_SHDR, ec) == 0); - assert(ex->ex_start == shoff); - - (void) memset(&dst, 0, sizeof(dst)); - (void) memset(&src, 0, sizeof(src)); - - 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 = nf + ex->ex_start + scn->s_ndx * fsz; - - if (_libelf_xlate(&dst, &src, e->e_byteorder, ec, - ELF_TOFILE) == NULL) - return ((off_t) -1); - } - - return (ex->ex_start + nscn * fsz); -} - -/* - * 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, struct _Elf_Extent_List *extents) -{ - off_t nrc, rc; - char *newfile; - Elf_Scn *scn, *tscn; - struct _Elf_Extent *ex; - - assert(e->e_kind == ELF_K_ELF); - assert(e->e_cmd == ELF_C_RDWR || e->e_cmd == ELF_C_WRITE); - assert(e->e_fd >= 0); - - if ((newfile = malloc((size_t) newsize)) == NULL) { - LIBELF_SET_ERROR(RESOURCE, errno); - return ((off_t) -1); - } - - nrc = rc = 0; - SLIST_FOREACH(ex, extents, ex_next) { - - /* Fill inter-extent gaps. */ - if (ex->ex_start > (size_t) rc) - (void) memset(newfile + rc, LIBELF_PRIVATE(fillchar), - ex->ex_start - rc); - - switch (ex->ex_type) { - case ELF_EXTENT_EHDR: - if ((nrc = _libelf_write_ehdr(e, newfile, ex)) < 0) - goto error; - break; - - case ELF_EXTENT_PHDR: - if ((nrc = _libelf_write_phdr(e, newfile, ex)) < 0) - goto error; - break; - - case ELF_EXTENT_SECTION: - if ((nrc = _libelf_write_scn(e, newfile, ex)) < 0) - goto error; - break; - - case ELF_EXTENT_SHDR: - if ((nrc = _libelf_write_shdr(e, newfile, ex)) < 0) - goto error; - break; - - default: - assert(0); - break; - } - - assert(ex->ex_start + ex->ex_size == (size_t) nrc); - assert(rc < nrc); - - rc = nrc; - } - - assert(rc == newsize); - - /* - * For regular files, throw away existing file content and - * unmap any existing mappings. - */ - if ((e->e_flags & LIBELF_F_SPECIAL_FILE) == 0) { - if (ftruncate(e->e_fd, (off_t) 0) < 0 || - lseek(e->e_fd, (off_t) 0, SEEK_SET)) { - LIBELF_SET_ERROR(IO, errno); - goto error; - } - if (e->e_flags & LIBELF_F_RAWFILE_MMAP) { - assert(e->e_rawfile != NULL); - assert(e->e_cmd == ELF_C_RDWR); - if (munmap(e->e_rawfile, e->e_rawsize) < 0) { - LIBELF_SET_ERROR(IO, errno); - goto error; - } - } - } - - /* - * Write out the new contents. - */ - if (write(e->e_fd, newfile, (size_t) newsize) != newsize) { - LIBELF_SET_ERROR(IO, errno); - goto error; - } - - /* - * For files opened in ELF_C_RDWR mode, set up the new 'raw' - * contents. - */ - if (e->e_cmd == ELF_C_RDWR) { - assert(e->e_rawfile != NULL); - if (e->e_flags & LIBELF_F_RAWFILE_MMAP) { - 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; - } - } else if (e->e_flags & LIBELF_F_RAWFILE_MALLOC) { - free(e->e_rawfile); - e->e_rawfile = newfile; - newfile = NULL; - } - - /* Record the new size of the file. */ - e->e_rawsize = newsize; - } else { - /* File opened in ELF_C_WRITE mode. */ - assert(e->e_rawfile == NULL); - } - - /* - * 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 (e->e_class == 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 the temporary buffer. */ - if (newfile) - free(newfile); - - return (rc); - - error: - free(newfile); - - return ((off_t) -1); -} - -/* - * Update an ELF object. - */ - -off_t -elf_update(Elf *e, Elf_Cmd c) -{ - int ec; - off_t rc; - struct _Elf_Extent_List extents; - - 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); - } - - SLIST_INIT(&extents); - - if ((rc = _libelf_resync_elf(e, &extents)) < 0) - goto done; - - if (c == ELF_C_NULL) - goto done; - - if (e->e_fd < 0) { - rc = (off_t) -1; - LIBELF_SET_ERROR(SEQUENCE, 0); - goto done; - } - - return (_libelf_write_elf(e, rc, &extents)); - -done: - _libelf_release_extents(&extents); - return (rc); -} |