100 lines
2.8 KiB
C
100 lines
2.8 KiB
C
/*
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* This file is part of ltrace.
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* Copyright (C) 2012 Petr Machata, Red Hat Inc.
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* Copyright (C) 2008,2009 Juan Cespedes
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* Copyright (C) 2006 Ian Wienand
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of the
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* License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
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* 02110-1301 USA
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*/
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#include <errno.h>
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#include <gelf.h>
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#include <stdio.h>
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#include <string.h>
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#include <sys/ptrace.h>
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#include "proc.h"
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#include "common.h"
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#include "library.h"
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/* A bundle is 128 bits. */
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#define BUNDLE_SIZE 16
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/* The PLT has
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*
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* - 3 bundles as a header
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*
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* - The special reserved entry
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*
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* - Following that, each PLT entry has it's initial code that the GOT
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* entry points to. Each PLT entry has one bundle allocated.
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*
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* - Following that, each PLT entry has two bundles of actual PLT
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* code, i.e. load up the address from the GOT and jump to it. This
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* is the point we want to insert the breakpoint, as this will be
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* captured every time we jump to the PLT entry in the code.
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*/
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GElf_Addr
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arch_plt_sym_val(struct ltelf *lte, size_t ndx, GElf_Rela * rela)
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{
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/* Find number of entires by removing header and special
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* entry, dividing total size by three, since each PLT entry
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* will have 3 bundles (1 for inital entry and two for the PLT
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* code). */
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int entries = (lte->plt_size - 4 * BUNDLE_SIZE) / (3 * BUNDLE_SIZE);
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/* Now the point we want to break on is the PLT entry after
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* all the header stuff */
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unsigned long addr =
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lte->plt_addr + (4 * BUNDLE_SIZE) + (BUNDLE_SIZE * entries) +
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(2 * ndx * BUNDLE_SIZE);
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debug(3, "Found PLT %zd entry at %lx", ndx, addr);
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return addr;
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}
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void *
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sym2addr(struct process *proc, struct library_symbol *sym)
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{
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return sym->enter_addr;
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}
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int
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arch_translate_address_dyn(struct process *proc,
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arch_addr_t addr, arch_addr_t *ret)
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{
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errno = 0;
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unsigned long l = ptrace(PTRACE_PEEKTEXT, proc->pid, addr, 0);
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if (l == -1UL && errno) {
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fprintf(stderr, "dynamic .opd translation of %p: %s\n",
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addr, strerror(errno));
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return -1;
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}
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/* XXX The double cast should be removed when
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* arch_addr_t becomes integral type. */
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*ret = (arch_addr_t)(uintptr_t)l;
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return 0;
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}
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int
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arch_translate_address(struct ltelf *lte,
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arch_addr_t addr, arch_addr_t *ret)
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{
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*ret = addr;
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return 0;
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}
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