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/*
* KME helpers to read ELF core files.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
* 02111-1307, USA.
*/
#include "config.h"
#include <stdio.h>
#include <malloc.h>
#include <errno.h>
#include <fcntl.h>
#include "elfcore.h"
#if HAVE_UNISTD_H
# include <unistd.h>
#endif
#if HAVE_STDLIB_H
# include <stdlib.h>
#endif
#if HAVE_LIBELF
# if HAVE_LIBELF_LIBELF_H
# include <libelf/libelf.h>
# else
# include <libelf.h>
#endif
static Elf32_Phdr *phdr;
static Elf32_Ehdr *ehdr;
static int elf_fd;
/*
* Internal initializations when 'read from corefile' is selected.
*/
int
read_corefile(const char *fname)
{
Elf *elf;
elf_fd = open(fname, O_RDONLY);
if (elf_version(EV_CURRENT) == EV_NONE) {
fprintf(stderr, "Elf library out of sync\n");
return 1;
}
elf = elf_begin(elf_fd, ELF_C_READ, NULL);
ehdr = elf32_getehdr(elf);
phdr = elf32_getphdr(elf);
if (ehdr == NULL || phdr == NULL) {
return 1;
}
return 0;
}
/*
* Given a start/length pair, return the number of successive bytes
* that can be read (can be less than requested if near the end of a
* phdr) and the offset in the source file whence it can be found.
*/
long
find_in_corefile(long addr, long ct, off_t *offset)
{
int i;
Elf32_Addr eaddr = (Elf32_Addr) addr;
Elf32_Phdr *pp = phdr;
for (i = 0; i < ehdr->e_phnum; i++, pp++) {
if ((eaddr >= pp->p_vaddr ) &&
(eaddr <= (pp->p_vaddr + pp->p_memsz))) {
*offset = eaddr - pp->p_vaddr + pp->p_offset;
if (eaddr + ct > pp->p_vaddr + pp->p_memsz)
return pp->p_vaddr + pp->p_memsz - eaddr;
else
return ct;
}
}
return -1;
}
/*
* Called from getmem to do the actual read of 'sz' bytes from address 'a'
* and put them in the 'tgtmem' buffer.
*/
int
getmem_from_corefile(int sz, long a, void *tgmem)
{
off_t off;
long n;
n = find_in_corefile(a, sz, &off);
if (n < 0) {
*(int *)tgmem = -1;
return -1;
}
if (lseek(elf_fd, off, SEEK_SET) != off ||
read(elf_fd, tgmem, n) != sz ) {
*(int*)tgmem = errno;
return -1;
}
return sz;
}
#else /* HAVE_LIBELF */
long
find_in_corefile(long addr, long ct, off_t *offset)
{
/* unreachable */
abort();
}
int
getmem_from_corefile(int sz, long a, void *tgmem)
{
/* unreachable */
abort();
}
int
read_corefile(const char *fname)
{
fprintf(stderr,
"This build of KME does not have libelf configured in.\n");
return 1;
}
#endif /* HAVE_LIBELF */