cf781b2e16
This brings a number of fixes to elfcopy/strip and DWARF4 improvements. Sponsored by: The FreeBSD Foundation
133 lines
3.6 KiB
C
133 lines
3.6 KiB
C
/*-
|
|
* Copyright (c) 2006,2008 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/param.h>
|
|
|
|
#include <assert.h>
|
|
#include <gelf.h>
|
|
|
|
#include "_libelf.h"
|
|
|
|
ELFTC_VCSID("$Id: elf_strptr.c 2990 2014-03-17 09:56:58Z jkoshy $");
|
|
|
|
/*
|
|
* Convert an ELF section#,offset pair to a string pointer.
|
|
*/
|
|
|
|
char *
|
|
elf_strptr(Elf *e, size_t scndx, size_t offset)
|
|
{
|
|
Elf_Scn *s;
|
|
Elf_Data *d;
|
|
GElf_Shdr shdr;
|
|
uint64_t alignment, count;
|
|
|
|
if (e == NULL || e->e_kind != ELF_K_ELF) {
|
|
LIBELF_SET_ERROR(ARGUMENT, 0);
|
|
return (NULL);
|
|
}
|
|
|
|
if ((s = elf_getscn(e, scndx)) == NULL ||
|
|
gelf_getshdr(s, &shdr) == NULL)
|
|
return (NULL);
|
|
|
|
if (shdr.sh_type != SHT_STRTAB ||
|
|
offset >= shdr.sh_size) {
|
|
LIBELF_SET_ERROR(ARGUMENT, 0);
|
|
return (NULL);
|
|
}
|
|
|
|
d = NULL;
|
|
if (e->e_flags & ELF_F_LAYOUT) {
|
|
|
|
/*
|
|
* The application is taking responsibility for the
|
|
* ELF object's layout, so we can directly translate
|
|
* an offset to a `char *' address using the `d_off'
|
|
* members of Elf_Data descriptors.
|
|
*/
|
|
while ((d = elf_getdata(s, d)) != NULL) {
|
|
|
|
if (d->d_buf == 0 || d->d_size == 0)
|
|
continue;
|
|
|
|
if (d->d_type != ELF_T_BYTE) {
|
|
LIBELF_SET_ERROR(DATA, 0);
|
|
return (NULL);
|
|
}
|
|
|
|
if (offset >= d->d_off &&
|
|
offset < d->d_off + d->d_size)
|
|
return ((char *) d->d_buf + offset - d->d_off);
|
|
}
|
|
} else {
|
|
/*
|
|
* Otherwise, the `d_off' members are not useable and
|
|
* we need to compute offsets ourselves, taking into
|
|
* account 'holes' in coverage of the section introduced
|
|
* by alignment requirements.
|
|
*/
|
|
count = (uint64_t) 0; /* cumulative count of bytes seen */
|
|
while ((d = elf_getdata(s, d)) != NULL && count <= offset) {
|
|
|
|
if (d->d_buf == NULL || d->d_size == 0)
|
|
continue;
|
|
|
|
if (d->d_type != ELF_T_BYTE) {
|
|
LIBELF_SET_ERROR(DATA, 0);
|
|
return (NULL);
|
|
}
|
|
|
|
if ((alignment = d->d_align) > 1) {
|
|
if ((alignment & (alignment - 1)) != 0) {
|
|
LIBELF_SET_ERROR(DATA, 0);
|
|
return (NULL);
|
|
}
|
|
count = roundup2(count, alignment);
|
|
}
|
|
|
|
if (offset < count) {
|
|
/* offset starts in the 'hole' */
|
|
LIBELF_SET_ERROR(ARGUMENT, 0);
|
|
return (NULL);
|
|
}
|
|
|
|
if (offset < count + d->d_size) {
|
|
if (d->d_buf != NULL)
|
|
return ((char *) d->d_buf +
|
|
offset - count);
|
|
LIBELF_SET_ERROR(DATA, 0);
|
|
return (NULL);
|
|
}
|
|
|
|
count += d->d_size;
|
|
}
|
|
}
|
|
|
|
LIBELF_SET_ERROR(ARGUMENT, 0);
|
|
return (NULL);
|
|
}
|