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https://github.com/Zenithsiz/ftmemsim-valgrind.git
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when the interpreter is loaded at a different address than what it asked for. git-svn-id: svn://svn.valgrind.org/valgrind/trunk@5576
828 lines
24 KiB
C
828 lines
24 KiB
C
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/*--------------------------------------------------------------------*/
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/*--- User-mode execve(), and other stuff shared between stage1 ---*/
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/*--- and stage2. m_ume.c ---*/
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/*--------------------------------------------------------------------*/
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/*
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This file is part of Valgrind, a dynamic binary instrumentation
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framework.
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Copyright (C) 2000-2005 Julian Seward
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jseward@acm.org
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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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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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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., 59 Temple Place, Suite 330, Boston, MA
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02111-1307, USA.
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The GNU General Public License is contained in the file COPYING.
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*/
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#define _GNU_SOURCE
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#define _FILE_OFFSET_BITS 64
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// It seems that on SuSE 9.1 (x86) something in <fcntl.h> messes up stuff
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// acquired indirectly from vki-x86-linux.h. Therefore our headers must be
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// included ahead of the glibc ones. This fix is a kludge; the right
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// solution is to entirely remove the glibc dependency.
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#include "pub_core_basics.h"
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#include "pub_core_aspacemgr.h" // various mapping fns
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#include "pub_core_debuglog.h"
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#include "pub_core_libcbase.h"
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#include "pub_core_machine.h"
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#include "pub_core_libcprint.h"
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#include "pub_core_libcfile.h" // VG_(close) et al
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#include "pub_core_libcproc.h" // VG_(geteuid), VG_(getegid)
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#include "pub_core_libcassert.h" // VG_(exit), vg_assert
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#include "pub_core_mallocfree.h" // VG_(malloc), VG_(free)
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#include "pub_core_syscall.h" // VG_(strerror)
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#include "vki_unistd.h" // mmap-related constants
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#include "pub_core_ume.h"
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#if VG_WORDSIZE == 8
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#define ESZ(x) Elf64_##x
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#elif VG_WORDSIZE == 4
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#define ESZ(x) Elf32_##x
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#else
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#error VG_WORDSIZE needs to ==4 or ==8
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#endif
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struct elfinfo
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{
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ESZ(Ehdr) e;
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ESZ(Phdr) *p;
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Int fd;
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};
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static void check_mmap(SysRes res, Addr base, SizeT len)
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{
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if (res.isError) {
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VG_(printf)("valgrind: mmap(0x%llx, %lld) failed in UME.\n",
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(ULong)base, (Long)len);
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VG_(exit)(1);
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}
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}
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/*------------------------------------------------------------*/
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/*--- Finding auxv on the stack ---*/
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/*------------------------------------------------------------*/
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struct ume_auxv *VG_(find_auxv)(UWord* sp)
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{
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sp++; // skip argc (Nb: is word-sized, not int-sized!)
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while (*sp != 0) // skip argv
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sp++;
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sp++;
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while (*sp != 0) // skip env
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sp++;
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sp++;
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#if defined(VGA_ppc32) || defined(VGA_ppc64)
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# if defined AT_IGNOREPPC
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while (*sp == AT_IGNOREPPC) // skip AT_IGNOREPPC entries
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sp += 2;
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# endif
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#endif
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return (struct ume_auxv *)sp;
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}
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/*------------------------------------------------------------*/
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/*--- Loading ELF files ---*/
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/*------------------------------------------------------------*/
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static
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struct elfinfo *readelf(Int fd, const char *filename)
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{
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SysRes sres;
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struct elfinfo *e = VG_(malloc)(sizeof(*e));
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Int phsz;
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vg_assert(e);
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e->fd = fd;
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sres = VG_(pread)(fd, &e->e, sizeof(e->e), 0);
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if (sres.isError || sres.val != sizeof(e->e)) {
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VG_(printf)("valgrind: %s: can't read ELF header: %s\n",
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filename, VG_(strerror)(sres.val));
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goto bad;
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}
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if (VG_(memcmp)(&e->e.e_ident[0], ELFMAG, SELFMAG) != 0) {
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VG_(printf)("valgrind: %s: bad ELF magic number\n", filename);
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goto bad;
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}
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if (e->e.e_ident[EI_CLASS] != VG_ELF_CLASS) {
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VG_(printf)("valgrind: wrong ELF executable class "
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"(eg. 32-bit instead of 64-bit)\n");
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goto bad;
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}
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if (e->e.e_ident[EI_DATA] != VG_ELF_DATA2XXX) {
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VG_(printf)("valgrind: executable has wrong endian-ness\n");
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goto bad;
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}
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if (!(e->e.e_type == ET_EXEC || e->e.e_type == ET_DYN)) {
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VG_(printf)("valgrind: this is not an executable\n");
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goto bad;
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}
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if (e->e.e_machine != VG_ELF_MACHINE) {
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VG_(printf)("valgrind: executable is not for "
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"this architecture\n");
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goto bad;
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}
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if (e->e.e_phentsize != sizeof(ESZ(Phdr))) {
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VG_(printf)("valgrind: sizeof ELF Phdr wrong\n");
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goto bad;
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}
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phsz = sizeof(ESZ(Phdr)) * e->e.e_phnum;
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e->p = VG_(malloc)(phsz);
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vg_assert(e->p);
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sres = VG_(pread)(fd, e->p, phsz, e->e.e_phoff);
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if (sres.isError || sres.val != phsz) {
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VG_(printf)("valgrind: can't read phdr: %s\n",
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VG_(strerror)(sres.val));
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VG_(free)(e->p);
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goto bad;
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}
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return e;
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bad:
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VG_(free)(e);
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return NULL;
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}
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/* Map an ELF file. Returns the brk address. */
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static
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ESZ(Addr) mapelf(struct elfinfo *e, ESZ(Addr) base)
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{
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Int i;
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SysRes res;
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ESZ(Addr) elfbrk = 0;
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for(i = 0; i < e->e.e_phnum; i++) {
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ESZ(Phdr) *ph = &e->p[i];
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ESZ(Addr) addr, brkaddr;
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ESZ(Word) memsz;
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if (ph->p_type != PT_LOAD)
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continue;
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addr = ph->p_vaddr+base;
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memsz = ph->p_memsz;
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brkaddr = addr+memsz;
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if (brkaddr > elfbrk)
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elfbrk = brkaddr;
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}
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for(i = 0; i < e->e.e_phnum; i++) {
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ESZ(Phdr) *ph = &e->p[i];
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ESZ(Addr) addr, bss, brkaddr;
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ESZ(Off) off;
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ESZ(Word) filesz;
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ESZ(Word) memsz;
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unsigned prot = 0;
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if (ph->p_type != PT_LOAD)
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continue;
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if (ph->p_flags & PF_X) prot |= VKI_PROT_EXEC;
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if (ph->p_flags & PF_W) prot |= VKI_PROT_WRITE;
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if (ph->p_flags & PF_R) prot |= VKI_PROT_READ;
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addr = ph->p_vaddr+base;
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off = ph->p_offset;
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filesz = ph->p_filesz;
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bss = addr+filesz;
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memsz = ph->p_memsz;
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brkaddr = addr+memsz;
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// Tom says: In the following, do what the Linux kernel does and only
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// map the pages that are required instead of rounding everything to
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// the specified alignment (ph->p_align). (AMD64 doesn't work if you
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// use ph->p_align -- part of stage2's memory gets trashed somehow.)
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//
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// The condition handles the case of a zero-length segment.
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if (VG_PGROUNDUP(bss)-VG_PGROUNDDN(addr) > 0) {
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if (0) VG_(debugLog)(0,"ume","mmap_file_fixed_client #1\n");
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res = VG_(am_mmap_file_fixed_client)(
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VG_PGROUNDDN(addr),
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VG_PGROUNDUP(bss)-VG_PGROUNDDN(addr),
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prot, /*VKI_MAP_FIXED|VKI_MAP_PRIVATE, */
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e->fd, VG_PGROUNDDN(off)
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);
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if (0) VG_(am_show_nsegments)(0,"after #1");
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check_mmap(res, VG_PGROUNDDN(addr),
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VG_PGROUNDUP(bss)-VG_PGROUNDDN(addr));
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}
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// if memsz > filesz, fill the remainder with zeroed pages
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if (memsz > filesz) {
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UInt bytes;
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bytes = VG_PGROUNDUP(brkaddr)-VG_PGROUNDUP(bss);
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if (bytes > 0) {
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if (0) VG_(debugLog)(0,"ume","mmap_anon_fixed_client #2\n");
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res = VG_(am_mmap_anon_fixed_client)(
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VG_PGROUNDUP(bss), bytes,
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prot
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);
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if (0) VG_(am_show_nsegments)(0,"after #2");
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check_mmap(res, VG_PGROUNDUP(bss), bytes);
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}
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bytes = bss & (VKI_PAGE_SIZE - 1);
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// The 'prot' condition allows for a read-only bss
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if ((prot & VKI_PROT_WRITE) && (bytes > 0)) {
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bytes = VKI_PAGE_SIZE - bytes;
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VG_(memset)((char *)bss, 0, bytes);
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}
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}
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}
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return elfbrk;
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}
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static Bool match_ELF(const char *hdr, Int len)
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{
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ESZ(Ehdr) *e = (ESZ(Ehdr) *)hdr;
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return (len > sizeof(*e)) && VG_(memcmp)(&e->e_ident[0], ELFMAG, SELFMAG) == 0;
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}
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/* load_ELF pulls an ELF executable into the address space, prepares
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it for execution, and writes info about it into INFO. In
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particular it fills in .init_eip, which is the starting point.
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Returns zero on success, non-zero (a VKI_E.. value) on failure.
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The sequence of activities is roughly as follows:
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- use readelf() to extract program header info from the exe file.
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- scan the program header, collecting info (not sure what all those
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info-> fields are, or whether they are used, but still) and in
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particular looking out fo the PT_INTERP header, which describes
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the interpreter. If such a field is found, the space needed to
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hold the interpreter is computed into interp_size.
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- map the executable in, by calling mapelf(). This maps in all
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loadable sections, and I _think_ also creates any .bss areas
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required. mapelf() returns the address just beyond the end of
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the furthest-along mapping it creates. The executable is mapped
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starting at EBASE, which is usually read from it (eg, 0x8048000
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etc) except if it's a PIE, in which case I'm not sure what
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happens.
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The returned address is recorded in info->brkbase as the start
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point of the brk (data) segment, as it is traditional to place
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the data segment just after the executable. Neither load_ELF nor
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mapelf creates the brk segment, though: that is for the caller of
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load_ELF to attend to.
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- If the initial phdr scan didn't find any mention of an
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interpreter (interp == NULL), this must be a statically linked
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executable, and we're pretty much done.
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- Otherwise, we need to use mapelf() a second time to load the
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interpreter. The interpreter can go anywhere, but mapelf() wants
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to be told a specific address to put it at. So an advisory query
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is passed to aspacem, asking where it would put an anonymous
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client mapping of size INTERP_SIZE. That address is then used
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as the mapping address for the interpreter.
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- The entry point in INFO is set to the interpreter's entry point,
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and we're done. */
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static Int load_ELF(Int fd, const HChar* name, /*MOD*/ExeInfo* info)
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{
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SysRes sres;
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struct elfinfo *e;
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struct elfinfo *interp = NULL;
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ESZ(Addr) minaddr = ~0; /* lowest mapped address */
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ESZ(Addr) maxaddr = 0; /* highest mapped address */
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ESZ(Addr) interp_addr = 0; /* interpreter (ld.so) address */
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ESZ(Word) interp_size = 0; /* interpreter size */
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ESZ(Word) interp_align = VKI_PAGE_SIZE;
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Int i;
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void *entry;
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ESZ(Addr) ebase = 0;
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|
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/* The difference between where the interpreter got mapped and
|
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where it asked to be mapped. Needed for computing the ppc64 ELF
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entry point and initial tocptr (R2) value. */
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ESZ(Word) interp_offset = 0;
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#ifdef HAVE_PIE
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ebase = info->exe_base;
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#endif
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e = readelf(fd, name);
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if (e == NULL)
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return VKI_ENOEXEC;
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|
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/* The kernel maps position-independent executables at TASK_SIZE*2/3;
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duplicate this behavior as close as we can. */
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if (e->e.e_type == ET_DYN && ebase == 0) {
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ebase = VG_PGROUNDDN(info->exe_base + (info->exe_end - info->exe_base) * 2 / 3);
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}
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info->phnum = e->e.e_phnum;
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info->entry = e->e.e_entry + ebase;
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info->phdr = 0;
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for(i = 0; i < e->e.e_phnum; i++) {
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ESZ(Phdr) *ph = &e->p[i];
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switch(ph->p_type) {
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case PT_PHDR:
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info->phdr = ph->p_vaddr + ebase;
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break;
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case PT_LOAD:
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if (ph->p_vaddr < minaddr)
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minaddr = ph->p_vaddr;
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if (ph->p_vaddr+ph->p_memsz > maxaddr)
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maxaddr = ph->p_vaddr+ph->p_memsz;
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break;
|
|
|
|
case PT_INTERP: {
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char *buf = VG_(malloc)(ph->p_filesz+1);
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Int j;
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Int intfd;
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Int baseaddr_set;
|
|
|
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vg_assert(buf);
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VG_(pread)(fd, buf, ph->p_filesz, ph->p_offset);
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buf[ph->p_filesz] = '\0';
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|
|
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sres = VG_(open)(buf, VKI_O_RDONLY, 0);
|
|
if (sres.isError) {
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|
VG_(printf)("valgrind: m_ume.c: can't open interpreter\n");
|
|
VG_(exit)(1);
|
|
}
|
|
intfd = sres.val;
|
|
|
|
interp = readelf(intfd, buf);
|
|
if (interp == NULL) {
|
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VG_(printf)("valgrind: m_ume.c: can't read interpreter\n");
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|
return 1;
|
|
}
|
|
VG_(free)(buf);
|
|
|
|
baseaddr_set = 0;
|
|
for(j = 0; j < interp->e.e_phnum; j++) {
|
|
ESZ(Phdr) *iph = &interp->p[j];
|
|
ESZ(Addr) end;
|
|
|
|
if (iph->p_type != PT_LOAD)
|
|
continue;
|
|
|
|
if (!baseaddr_set) {
|
|
interp_addr = iph->p_vaddr;
|
|
interp_align = iph->p_align;
|
|
baseaddr_set = 1;
|
|
}
|
|
|
|
/* assumes that all segments in the interp are close */
|
|
end = (iph->p_vaddr - interp_addr) + iph->p_memsz;
|
|
|
|
if (end > interp_size)
|
|
interp_size = end;
|
|
}
|
|
break;
|
|
|
|
default:
|
|
// do nothing
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (info->phdr == 0)
|
|
info->phdr = minaddr + ebase + e->e.e_phoff;
|
|
|
|
if (info->exe_base != info->exe_end) {
|
|
if (minaddr >= maxaddr ||
|
|
(minaddr + ebase < info->exe_base ||
|
|
maxaddr + ebase > info->exe_end)) {
|
|
VG_(printf)("Executable range %p-%p is outside the\n"
|
|
"acceptable range %p-%p\n",
|
|
(char *)minaddr + ebase, (char *)maxaddr + ebase,
|
|
(char *)info->exe_base, (char *)info->exe_end);
|
|
return VKI_ENOMEM;
|
|
}
|
|
}
|
|
|
|
info->brkbase = mapelf(e, ebase); /* map the executable */
|
|
|
|
if (info->brkbase == 0)
|
|
return VKI_ENOMEM;
|
|
|
|
if (interp != NULL) {
|
|
/* reserve a chunk of address space for interpreter */
|
|
MapRequest mreq;
|
|
Addr advised;
|
|
Bool ok;
|
|
|
|
/* Don't actually reserve the space. Just get an advisory
|
|
indicating where it would be allocated, and pass that to
|
|
mapelf(), which in turn asks aspacem to do some fixed maps at
|
|
the specified address. This is a bit of hack, but it should
|
|
work because there should be no intervening transactions with
|
|
aspacem which could cause those fixed maps to fail.
|
|
|
|
Placement policy is:
|
|
|
|
if the interpreter asks to be loaded at zero
|
|
ignore that and put it wherever we like (mappings at zero
|
|
are bad news)
|
|
else
|
|
try and put it where it asks for, but if that doesn't work,
|
|
just put it anywhere.
|
|
*/
|
|
if (interp_addr == 0) {
|
|
mreq.rkind = MAny;
|
|
mreq.start = 0;
|
|
mreq.len = interp_size;
|
|
} else {
|
|
mreq.rkind = MHint;
|
|
mreq.start = interp_addr;
|
|
mreq.len = interp_size;
|
|
}
|
|
|
|
advised = VG_(am_get_advisory)( &mreq, True/*client*/, &ok );
|
|
|
|
if (!ok) {
|
|
/* bomb out */
|
|
SysRes res = VG_(mk_SysRes_Error)(VKI_EINVAL);
|
|
if (0) VG_(printf)("reserve for interp: failed\n");
|
|
check_mmap(res, (Addr)interp_addr, interp_size);
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
(void)mapelf(interp, (ESZ(Addr))advised - interp_addr);
|
|
|
|
VG_(close)(interp->fd);
|
|
|
|
entry = (void *)(advised - interp_addr + interp->e.e_entry);
|
|
info->interp_base = (ESZ(Addr))advised;
|
|
interp_offset = advised - interp_addr;
|
|
|
|
VG_(free)(interp->p);
|
|
VG_(free)(interp);
|
|
} else
|
|
entry = (void *)(ebase + e->e.e_entry);
|
|
|
|
info->exe_base = minaddr + ebase;
|
|
info->exe_end = maxaddr + ebase;
|
|
|
|
#if defined(VGP_ppc64_linux)
|
|
/* On PPC64, a func ptr is represented by a TOC entry ptr. This
|
|
TOC entry contains three words; the first word is the function
|
|
address, the second word is the TOC ptr (r2), and the third word
|
|
is the static chain value. */
|
|
info->init_ip = ((ULong*)entry)[0];
|
|
info->init_toc = ((ULong*)entry)[1];
|
|
info->init_ip += interp_offset;
|
|
info->init_toc += interp_offset;
|
|
#else
|
|
info->init_ip = (Addr)entry;
|
|
info->init_toc = 0; /* meaningless on this platform */
|
|
#endif
|
|
VG_(free)(e->p);
|
|
VG_(free)(e);
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
static Bool match_script(char *hdr, Int len)
|
|
{
|
|
Char* end = hdr + len;
|
|
Char* interp = hdr + 2;
|
|
|
|
// len < 4: need '#', '!', plus at least a '/' and one more char
|
|
if (len < 4) return False;
|
|
if (0 != VG_(memcmp)(hdr, "#!", 2)) return False;
|
|
|
|
// Find interpreter name, make sure it's an absolute path (starts with
|
|
// '/') and has at least one more char.
|
|
while (interp < end && VG_(isspace)(*interp)) interp++;
|
|
if (*interp != '/') return False; // absolute path only for interpreter
|
|
if (interp == end) return False; // nothing after the '/'
|
|
|
|
// Here we should get the full interpreter name and check it with
|
|
// check_executable(). See the "EXEC FAILED" failure when running shell
|
|
// for an example.
|
|
|
|
return True; // looks like a #! script
|
|
}
|
|
|
|
// Forward declaration.
|
|
static Int do_exec_inner(const HChar* exe, ExeInfo* info);
|
|
|
|
/* returns: 0 = success, non-0 is failure */
|
|
static Int load_script(Int fd, const HChar* name, ExeInfo* info)
|
|
{
|
|
Char hdr[VKI_PAGE_SIZE];
|
|
Int len = VKI_PAGE_SIZE;
|
|
Int eol;
|
|
Char* interp;
|
|
Char* end;
|
|
Char* cp;
|
|
Char* arg = NULL;
|
|
SysRes res;
|
|
|
|
// Read the first part of the file.
|
|
res = VG_(pread)(fd, hdr, len, 0);
|
|
if (res.isError) {
|
|
VG_(close)(fd);
|
|
return VKI_EACCES;
|
|
} else {
|
|
len = res.val;
|
|
}
|
|
|
|
vg_assert('#' == hdr[0] && '!' == hdr[1]);
|
|
|
|
end = hdr + len;
|
|
interp = hdr + 2;
|
|
while (interp < end && VG_(isspace)(*interp))
|
|
interp++;
|
|
|
|
vg_assert(*interp == '/'); /* absolute path only for interpreter */
|
|
|
|
/* skip over interpreter name */
|
|
for (cp = interp; cp < end && !VG_(isspace)(*cp); cp++)
|
|
;
|
|
|
|
eol = (*cp == '\n');
|
|
|
|
*cp++ = '\0';
|
|
|
|
if (!eol && cp < end) {
|
|
/* skip space before arg */
|
|
while (cp < end && VG_(isspace)(*cp))
|
|
cp++;
|
|
|
|
/* arg is from here to eol */
|
|
arg = cp;
|
|
while (cp < end && *cp != '\n')
|
|
cp++;
|
|
*cp = '\0';
|
|
}
|
|
|
|
info->interp_name = VG_(strdup)(interp);
|
|
vg_assert(NULL != info->interp_name);
|
|
if (arg != NULL && *arg != '\0') {
|
|
info->interp_args = VG_(strdup)(arg);
|
|
vg_assert(NULL != info->interp_args);
|
|
}
|
|
|
|
if (info->argv && info->argv[0] != NULL)
|
|
info->argv[0] = (char *)name;
|
|
|
|
if (0)
|
|
VG_(printf)("#! script: interp_name=\"%s\" interp_args=\"%s\"\n",
|
|
info->interp_name, info->interp_args);
|
|
|
|
return do_exec_inner(interp, info);
|
|
}
|
|
|
|
|
|
typedef enum {
|
|
VG_EXE_FORMAT_ELF = 1,
|
|
VG_EXE_FORMAT_SCRIPT = 2,
|
|
} ExeFormat;
|
|
|
|
// Check the file looks executable.
|
|
SysRes VG_(pre_exec_check)(const HChar* exe_name, Int* out_fd)
|
|
{
|
|
Int fd, ret;
|
|
SysRes res;
|
|
Char buf[VKI_PAGE_SIZE];
|
|
SizeT bufsz = VKI_PAGE_SIZE, fsz;
|
|
|
|
// Check it's readable
|
|
res = VG_(open)(exe_name, VKI_O_RDONLY, 0);
|
|
if (res.isError) {
|
|
return res;
|
|
}
|
|
fd = res.val;
|
|
|
|
// Check we have execute permissions
|
|
ret = VG_(check_executable)((HChar*)exe_name);
|
|
if (0 != ret) {
|
|
VG_(close)(fd);
|
|
return VG_(mk_SysRes_Error)(ret);
|
|
}
|
|
|
|
fsz = VG_(fsize)(fd);
|
|
if (fsz < bufsz)
|
|
bufsz = fsz;
|
|
|
|
res = VG_(pread)(fd, buf, bufsz, 0);
|
|
if (res.isError || res.val != bufsz) {
|
|
VG_(close)(fd);
|
|
return VG_(mk_SysRes_Error)(VKI_EACCES);
|
|
}
|
|
bufsz = res.val;
|
|
|
|
if (match_ELF(buf, bufsz)) {
|
|
res = VG_(mk_SysRes_Success)(VG_EXE_FORMAT_ELF);
|
|
} else if (match_script(buf, bufsz)) {
|
|
res = VG_(mk_SysRes_Success)(VG_EXE_FORMAT_SCRIPT);
|
|
} else {
|
|
res = VG_(mk_SysRes_Error)(VKI_ENOEXEC);
|
|
}
|
|
|
|
// Write the 'out_fd' param if necessary, or close the file.
|
|
if (!res.isError && out_fd) {
|
|
*out_fd = fd;
|
|
} else {
|
|
VG_(close)(fd);
|
|
}
|
|
|
|
return res;
|
|
}
|
|
|
|
// returns: 0 = success, non-0 is failure
|
|
//
|
|
// We can execute only ELF binaries or scripts that begin with "#!". (Not,
|
|
// for example, scripts that don't begin with "#!"; see the VG_(do_exec)()
|
|
// invocation from m_main.c for how that's handled.)
|
|
static Int do_exec_inner(const HChar *exe, ExeInfo* info)
|
|
{
|
|
SysRes res;
|
|
Int fd;
|
|
Int ret;
|
|
|
|
res = VG_(pre_exec_check)(exe, &fd);
|
|
if (res.isError)
|
|
return res.val;
|
|
|
|
switch (res.val) {
|
|
case VG_EXE_FORMAT_ELF: ret = load_ELF (fd, exe, info); break;
|
|
case VG_EXE_FORMAT_SCRIPT: ret = load_script(fd, exe, info); break;
|
|
default:
|
|
vg_assert2(0, "unrecognised VG_EXE_FORMAT value\n");
|
|
}
|
|
|
|
VG_(close)(fd);
|
|
|
|
return ret;
|
|
}
|
|
|
|
|
|
static Bool is_hash_bang_file(Char* f)
|
|
{
|
|
SysRes res = VG_(open)(f, VKI_O_RDONLY, 0);
|
|
if (!res.isError) {
|
|
Char buf[3] = {0,0,0};
|
|
Int fd = res.val;
|
|
Int n = VG_(read)(fd, buf, 2);
|
|
if (n == 2 && VG_STREQ("#!", buf))
|
|
return True;
|
|
}
|
|
return False;
|
|
}
|
|
|
|
// Look at the first 80 chars, and if any are greater than 127, it's binary.
|
|
// This is crude, but should be good enough. Note that it fails on a
|
|
// zero-length file, as we want.
|
|
static Bool is_binary_file(Char* f)
|
|
{
|
|
SysRes res = VG_(open)(f, VKI_O_RDONLY, 0);
|
|
if (!res.isError) {
|
|
UChar buf[80];
|
|
Int fd = res.val;
|
|
Int n = VG_(read)(fd, buf, 80);
|
|
Int i;
|
|
for (i = 0; i < n; i++) {
|
|
if (buf[i] > 127)
|
|
return True; // binary char found
|
|
}
|
|
return False;
|
|
} else {
|
|
// Something went wrong. This will only happen if we earlier
|
|
// succeeded in opening the file but fail here (eg. the file was
|
|
// deleted between then and now).
|
|
VG_(printf)("valgrind: %s: unknown error\n", f);
|
|
VG_(exit)(126); // 126 == NOEXEC
|
|
}
|
|
}
|
|
|
|
// If the do_exec fails we try to emulate what the shell does (I used
|
|
// bash as a guide). It's worth noting that the shell can execute some
|
|
// things that VG_(do_exec)() (which subsitutes for the kernel's exec())
|
|
// will refuse to (eg. scripts lacking a "#!" prefix).
|
|
static Int do_exec_shell_followup(Int ret, HChar* exe_name,
|
|
ExeInfo* info)
|
|
{
|
|
Char* default_interp_name = "/bin/sh";
|
|
SysRes res;
|
|
struct vki_stat st;
|
|
|
|
if (VKI_ENOEXEC == ret) {
|
|
// It was an executable file, but in an unacceptable format. Probably
|
|
// is a shell script lacking the "#!" prefix; try to execute it so.
|
|
|
|
// Is it a binary file?
|
|
if (is_binary_file(exe_name)) {
|
|
VG_(printf)("valgrind: %s: cannot execute binary file\n", exe_name);
|
|
VG_(exit)(126); // 126 == NOEXEC
|
|
}
|
|
|
|
// Looks like a script. Run it with /bin/sh. This includes
|
|
// zero-length files.
|
|
|
|
info->interp_name = VG_(strdup)(default_interp_name);
|
|
info->interp_args = NULL;
|
|
if (info->argv && info->argv[0] != NULL)
|
|
info->argv[0] = (char *)exe_name;
|
|
|
|
ret = do_exec_inner(info->interp_name, info);
|
|
|
|
if (0 != ret) {
|
|
// Something went wrong with executing the default interpreter
|
|
VG_(printf)("valgrind: %s: bad interpreter (%s): %s\n",
|
|
exe_name, info->interp_name, VG_(strerror)(ret));
|
|
VG_(exit)(126); // 126 == NOEXEC
|
|
}
|
|
|
|
} else if (0 != ret) {
|
|
// Something else went wrong. Try to make the error more specific,
|
|
// and then print a message and abort.
|
|
|
|
// Was it a directory?
|
|
res = VG_(stat)(exe_name, &st);
|
|
if (!res.isError && VKI_S_ISDIR(st.st_mode)) {
|
|
VG_(printf)("valgrind: %s: is a directory\n", exe_name);
|
|
|
|
// Was it not executable?
|
|
} else if (0 != VG_(check_executable)(exe_name)) {
|
|
VG_(printf)("valgrind: %s: %s\n", exe_name, VG_(strerror)(ret));
|
|
|
|
// Did it start with "#!"? If so, it must have been a bad interpreter.
|
|
} else if (is_hash_bang_file(exe_name)) {
|
|
VG_(printf)("valgrind: %s: bad interpreter: %s\n",
|
|
exe_name, VG_(strerror)(ret));
|
|
|
|
// Otherwise it was something else.
|
|
} else {
|
|
VG_(printf)("valgrind: %s\n", exe_name, VG_(strerror)(ret));
|
|
}
|
|
// 126 means NOEXEC; I think this is Posix, and that in some cases we
|
|
// should be returning 127, meaning NOTFOUND. Oh well.
|
|
VG_(exit)(126);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
|
|
// This emulates the kernel's exec(). If it fails, it then emulates the
|
|
// shell's handling of the situation.
|
|
// See ume.h for an indication of which entries of 'info' are inputs, which
|
|
// are outputs, and which are both.
|
|
/* returns: 0 = success, non-0 is failure */
|
|
Int VG_(do_exec)(const HChar* exe_name, ExeInfo* info)
|
|
{
|
|
Int ret;
|
|
|
|
info->interp_name = NULL;
|
|
info->interp_args = NULL;
|
|
|
|
ret = do_exec_inner(exe_name, info);
|
|
|
|
if (0 != ret) {
|
|
ret = do_exec_shell_followup(ret, (Char*)exe_name, info);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/*--------------------------------------------------------------------*/
|
|
/*--- end ---*/
|
|
/*--------------------------------------------------------------------*/
|