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Do check-execstack test using readelf rather than a build-time C program.
This commit is contained in:
Roland McGrath
parent
82a79e7d18
commit
82397ed6ea
10
ChangeLog
10
ChangeLog
@ -1,5 +1,15 @@
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2012-05-01 Roland McGrath <roland@hack.frob.com>
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* scripts/check-execstack.awk: New file.
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* elf/Makefile ($(objpfx)check-execstack): Target removed.
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(check-execstack-CFLAGS): Variable removed.
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($(objpfx)check-execstack.h): Target removed.
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($(objpfx)execstack-default): New target.
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(generated): Add that instead of check-execstack.h.
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($(all-built-dso:=.phdr)): New static pattern rule.
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(generated): Add those targets.
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* elf/check-execstack.c: File removed.
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* scripts/check-textrel.awk: New file.
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* elf/Makefile ($(objpfx)check-textrel): Target removed.
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(check-textrel-CFLAGS): Variable removed.
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41
elf/Makefile
41
elf/Makefile
@ -872,18 +872,6 @@ CFLAGS-tst-pie1.c += $(pie-ccflag)
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$(objpfx)tst-pie1: $(objpfx)tst-piemod1.so
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check-execstack-CFLAGS = -O -Wall -D_XOPEN_SOURCE=600 -D_BSD_SOURCE -std=gnu99 \
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$(objpfx:%/=-I%)
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$(objpfx)check-execstack: check-execstack.c $(objpfx)check-execstack.h
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$(native-compile)
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$(objpfx)check-execstack.h: $(first-word $(wildcard $(sysdirs:%=%/stackinfo.h)))
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$(make-target-directory)
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{ echo '#include <stackinfo.h>'; echo '@@@DEFAULT_STACK_PERMS@@@'; } | \
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$(CC) $(CFLAGS) $(CPPFLAGS) -E -x c-header - | \
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sed -n -e 's/^@@@\(.*\)@@@/#define DEFAULT_STACK_PERMS \1/p' > $@T
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mv -f $@T $@
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generated += check-execstack.h
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check-localplt-CFLAGS = -O -Wall -D_GNU_SOURCE -std=gnu99
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$(objpfx)check-localplt: check-localplt.c
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$(native-compile)
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@ -909,9 +897,32 @@ $(objpfx)check-textrel.out: $(..)scripts/check-textrel.awk \
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LC_ALL=C $(AWK) -f $^ > $@
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generated += check-textrel.out
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$(objpfx)check-execstack.out: $(objpfx)check-execstack $(all-built-dso)
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$(dir $<)$(notdir $<) $(filter-out $<, $^) > $@
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generated += check-execstack check-execstack.out
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$(objpfx)execstack-default: $(first-word $(wildcard $(sysdirs:%=%/stackinfo.h)))
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$(make-target-directory)
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{ echo '#include <elf.h>'; \
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echo '#include <stackinfo.h>'; \
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echo '#if (DEFAULT_STACK_PERMS & PF_X) == 0'; \
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echo '@@@execstack-no@@@'; \
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echo '#else'; \
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echo '@@@execstack-yes@@@'; \
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echo '#endif'; } | \
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$(CC) $(CFLAGS) $(CPPFLAGS) -E -x c-header - | \
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sed -n -e 's/^@@@\(.*\)@@@/\1/p' > $@T
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mv -f $@T $@
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generated += execstack-default
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$(all-built-dso:=.phdr): %.phdr: %
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@rm -f $@T
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LC_ALL=C $(READELF) -W -l $< > $@T
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test -s $@T
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mv -f $@T $@
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generated += $(all-built-dso:=.phdr)
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$(objpfx)check-execstack.out: $(..)scripts/check-execstack.awk \
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$(objpfx)execstack-default \
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$(all-built-dso:=.phdr)
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LC_ALL=C $(AWK) -f $^ > $@
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generated += check-execstack.out
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$(objpfx)tst-dlmodcount: $(libdl)
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$(objpfx)tst-dlmodcount.out: $(test-modules)
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@ -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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52
scripts/check-execstack.awk
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52
scripts/check-execstack.awk
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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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