mirror of https://gitee.com/Nocallback/glibc.git
Roland McGrath
14 years ago
4 changed files with 88 additions and 177 deletions
@ -1,162 +0,0 @@ |
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/* Check for executable stacks in DSOs.
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Copyright (C) 2009, 2010 Free Software Foundation, Inc. |
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This file is part of the GNU C Library. |
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Contribute by Ulrich Drepper <drepper@redhat.com>. 2009. |
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The GNU C Library is free software; you can redistribute it and/or |
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modify it under the terms of the GNU Lesser General Public |
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License as published by the Free Software Foundation; either |
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version 2.1 of the License, or (at your option) any later version. |
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The GNU C Library is distributed in the hope that it will be useful, |
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but 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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Lesser General Public License for more details. |
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You should have received a copy of the GNU Lesser General Public |
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License along with the GNU C Library; if not, see |
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<http://www.gnu.org/licenses/>. */
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#include <byteswap.h> |
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#include <elf.h> |
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#include <endian.h> |
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#include <fcntl.h> |
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#include <stdio.h> |
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#include <stdlib.h> |
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#include <string.h> |
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#include <unistd.h> |
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#include "check-execstack.h" |
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#ifdef BITS |
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# define AB(name) _AB (name, BITS) |
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# define _AB(name, bits) __AB (name, bits) |
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# define __AB(name, bits) name##bits |
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# define E(name) _E (name, BITS) |
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# define _E(name, bits) __E (name, bits) |
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# define __E(name, bits) Elf##bits##_##name |
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# define SWAP(val) \ |
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({ __typeof (val) __res; \ |
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if (((ehdr.e_ident[EI_DATA] == ELFDATA2MSB \ |
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&& BYTE_ORDER == LITTLE_ENDIAN) \ |
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|| (ehdr.e_ident[EI_DATA] == ELFDATA2LSB \ |
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&& BYTE_ORDER == BIG_ENDIAN)) \ |
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&& sizeof (val) != 1) \ |
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{ \ |
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if (sizeof (val) == 2) \ |
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__res = bswap_16 (val); \ |
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else if (sizeof (val) == 4) \ |
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__res = bswap_32 (val); \ |
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else \ |
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__res = bswap_64 (val); \ |
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} \ |
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else \ |
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__res = (val); \ |
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__res; }) |
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static int |
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AB(handle_file) (const char *fname, int fd) |
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{ |
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E(Ehdr) ehdr; |
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if (pread (fd, &ehdr, sizeof (ehdr), 0) != sizeof (ehdr)) |
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{ |
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read_error: |
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printf ("%s: read error: %m\n", fname); |
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return 1; |
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} |
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const size_t phnum = SWAP (ehdr.e_phnum); |
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const size_t phentsize = SWAP (ehdr.e_phentsize); |
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/* Read the program header. */ |
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E(Phdr) *phdr = alloca (phentsize * phnum); |
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if (pread (fd, phdr, phentsize * phnum, SWAP (ehdr.e_phoff)) |
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!= phentsize * phnum) |
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goto read_error; |
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/* Search for the PT_GNU_STACK entry. */ |
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for (size_t cnt = 0; cnt < phnum; ++cnt) |
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if (SWAP (phdr[cnt].p_type) == PT_GNU_STACK) |
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{ |
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unsigned int flags = SWAP(phdr[cnt].p_flags); |
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if (flags & PF_X) |
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{ |
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printf ("%s: executable stack signaled\n", fname); |
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return 1; |
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} |
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return 0; |
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} |
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if (DEFAULT_STACK_PERMS & PF_X) |
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{ |
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printf ("%s: no PT_GNU_STACK entry\n", fname); |
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return 1; |
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} |
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return 0; |
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} |
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# undef BITS |
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#else |
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# define BITS 32 |
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# include "check-execstack.c" |
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# define BITS 64 |
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# include "check-execstack.c" |
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static int |
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handle_file (const char *fname) |
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{ |
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int fd = open (fname, O_RDONLY); |
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if (fd == -1) |
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{ |
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printf ("cannot open %s: %m\n", fname); |
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return 1; |
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} |
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/* Read was is supposed to be the ELF header. Read the initial
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bytes to determine whether this is a 32 or 64 bit file. */ |
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char ident[EI_NIDENT]; |
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if (read (fd, ident, EI_NIDENT) != EI_NIDENT) |
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{ |
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printf ("%s: read error: %m\n", fname); |
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close (fd); |
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return 1; |
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} |
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if (memcmp (&ident[EI_MAG0], ELFMAG, SELFMAG) != 0) |
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{ |
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printf ("%s: not an ELF file\n", fname); |
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close (fd); |
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return 1; |
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} |
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int result; |
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if (ident[EI_CLASS] == ELFCLASS64) |
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result = handle_file64 (fname, fd); |
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else |
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result = handle_file32 (fname, fd); |
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close (fd); |
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return result; |
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} |
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int |
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main (int argc, char *argv[]) |
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{ |
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int cnt; |
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int result = 0; |
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for (cnt = 1; cnt < argc; ++cnt) |
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result |= handle_file (argv[cnt]); |
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return result; |
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} |
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#endif |
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@ -0,0 +1,52 @@ |
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# This awk script expects to get command-line files that are each |
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# the output of 'readelf -l' on a single shared object. |
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# But the first file should contain just "execstack-no" or "execstack-yes", |
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# indicating what the default is in the absence of PT_GNU_STACK. |
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# It exits successfully (0) if none indicated executable stack. |
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# It fails (1) if any did indicate executable stack. |
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# It fails (2) if the input did not take the expected form. |
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BEGIN { result = sanity = 0; default_exec = -1 } |
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/^execstack-no$/ { default_exec = 0; next } |
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/^execstack-yes$/ { default_exec = 1; next } |
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function check_one(name) { |
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if (default_exec == -1) { |
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print "*** missing execstack-default file?"; |
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result = 2; |
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} |
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if (!sanity) { |
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print name ": *** input did not look like readelf -l output"; |
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result = 2; |
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} else if (stack_line) { |
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if (stack_line ~ /^.*RW .*$/) { |
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print name ": OK"; |
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} else if (stack_line ~ /^.*E.*$/) { |
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print name ": *** executable stack signaled"; |
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result = result ? result : 1; |
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} |
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} else if (default_exec) { |
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print name ": *** no PT_GNU_STACK entry"; |
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result = result ? result : 1; |
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} else { |
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print name ": no PT_GNU_STACK but default is OK"; |
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} |
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sanity = 0; |
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} |
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FILENAME != lastfile { |
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if (lastfile) |
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check_one(lastfile); |
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lastfile = FILENAME; |
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} |
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$1 == "Type" && $7 == "Flg" { sanity = 1; stack_line = "" } |
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$1 == "GNU_STACK" { stack_line = $0 } |
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END { |
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check_one(lastfile); |
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exit(result); |
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} |
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