/* * This file is part of ltrace. * Copyright (C) 2012 Petr Machata, Red Hat Inc. * Copyright (C) 2008,2009 Juan Cespedes * Copyright (C) 2006 Ian Wienand * * 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 of the * License, 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., 51 Franklin St, Fifth Floor, Boston, MA * 02110-1301 USA */ #include <errno.h> #include <gelf.h> #include <stdio.h> #include <string.h> #include <sys/ptrace.h> #include "proc.h" #include "common.h" #include "library.h" /* A bundle is 128 bits. */ #define BUNDLE_SIZE 16 /* The PLT has * * - 3 bundles as a header * * - The special reserved entry * * - Following that, each PLT entry has it's initial code that the GOT * entry points to. Each PLT entry has one bundle allocated. * * - Following that, each PLT entry has two bundles of actual PLT * code, i.e. load up the address from the GOT and jump to it. This * is the point we want to insert the breakpoint, as this will be * captured every time we jump to the PLT entry in the code. */ GElf_Addr arch_plt_sym_val(struct ltelf *lte, size_t ndx, GElf_Rela * rela) { /* Find number of entires by removing header and special * entry, dividing total size by three, since each PLT entry * will have 3 bundles (1 for inital entry and two for the PLT * code). */ int entries = (lte->plt_size - 4 * BUNDLE_SIZE) / (3 * BUNDLE_SIZE); /* Now the point we want to break on is the PLT entry after * all the header stuff */ unsigned long addr = lte->plt_addr + (4 * BUNDLE_SIZE) + (BUNDLE_SIZE * entries) + (2 * ndx * BUNDLE_SIZE); debug(3, "Found PLT %zd entry at %lx", ndx, addr); return addr; } void * sym2addr(struct process *proc, struct library_symbol *sym) { return sym->enter_addr; } int arch_translate_address_dyn(struct process *proc, arch_addr_t addr, arch_addr_t *ret) { errno = 0; unsigned long l = ptrace(PTRACE_PEEKTEXT, proc->pid, addr, 0); if (l == -1UL && errno) { fprintf(stderr, "dynamic .opd translation of %p: %s\n", addr, strerror(errno)); return -1; } /* XXX The double cast should be removed when * arch_addr_t becomes integral type. */ *ret = (arch_addr_t)(uintptr_t)l; return 0; } int arch_translate_address(struct ltelf *lte, arch_addr_t addr, arch_addr_t *ret) { *ret = addr; return 0; }