Test DSOs for executable stack.

Add a text program, built to run on the host, to check all newly
built DSOs for executable stacks and fail if the stack information
is missing or indicates executable stacks.
This commit is contained in:
Ulrich Drepper 2009-05-15 08:01:09 -07:00 committed by Ulrich Drepper
parent deb84c43b1
commit 774f5a3082
3 changed files with 175 additions and 2 deletions

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@ -1,3 +1,8 @@
2009-05-15 Ulrich Drepper <drepper@redhat.com>
* elf/check-execstack.c: New file.
* elf/Makefile: Add rules to build and run check-execstack.
2009-05-10 Ulrich Drepper <drepper@redhat.com>
* version.h (VERSION): Bump to 2.10.1.

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@ -93,7 +93,7 @@ distribute := rtld-Rules \
order2mod1.c order2mod2.c order2mod3.c order2mod4.c \
tst-stackguard1.c tst-stackguard1-static.c \
tst-array5.c tst-array5-static.c tst-array5dep.c \
tst-array5.exp tst-leaks1.c
tst-array5.exp tst-leaks1.c check-execstack.c
CFLAGS-dl-runtime.c = -fexceptions -fasynchronous-unwind-tables
CFLAGS-dl-lookup.c = -fexceptions -fasynchronous-unwind-tables
@ -842,12 +842,16 @@ check-textrel-CFLAGS = -O -Wall -D_XOPEN_SOURCE=600 -D_BSD_SOURCE
$(objpfx)check-textrel: check-textrel.c
$(native-compile)
check-execstack-CFLAGS = -O -Wall -D_XOPEN_SOURCE=600 -D_BSD_SOURCE -std=gnu99
$(objpfx)check-execstack: check-execstack.c
$(native-compile)
check-localplt-CFLAGS = -O -Wall -D_GNU_SOURCE -std=gnu99
$(objpfx)check-localplt: check-localplt.c
$(native-compile)
ifeq (yes,$(build-shared))
tests: $(objpfx)check-textrel.out
tests: $(objpfx)check-textrel.out $(objpfx)check-execstack.out
$(objpfx)check-textrel.out: $(objpfx)check-textrel
$(dir $<)$(notdir $<) $(common-objpfx)libc.so \
@ -855,6 +859,12 @@ $(objpfx)check-textrel.out: $(objpfx)check-textrel
$(common-objpfx)iconvdata/*.so)) > $@
generated += check-textrel check-textrel.out
$(objpfx)check-execstack.out: $(objpfx)check-execstack
$(dir $<)$(notdir $<) $(common-objpfx)libc.so \
$(sort $(wildcard $(common-objpfx)*/lib*.so \
$(common-objpfx)iconvdata/*.so)) > $@
generated += check-execstack check-execstack.out
$(objpfx)tst-dlmodcount: $(libdl)
$(objpfx)tst-dlmodcount.out: $(test-modules)

158
elf/check-execstack.c Normal file
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@ -0,0 +1,158 @@
/* Check for executable stacks in DSOs.
Copyright (C) 2009 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contribute by Ulrich Drepper <drepper@redhat.com>. 2009.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <byteswap.h>
#include <elf.h>
#include <endian.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#ifdef BITS
# define AB(name) _AB (name, BITS)
# define _AB(name, bits) __AB (name, bits)
# define __AB(name, bits) name##bits
# define E(name) _E (name, BITS)
# define _E(name, bits) __E (name, bits)
# define __E(name, bits) Elf##bits##_##name
# define SWAP(val) \
({ __typeof (val) __res; \
if (((ehdr.e_ident[EI_DATA] == ELFDATA2MSB \
&& BYTE_ORDER == LITTLE_ENDIAN) \
|| (ehdr.e_ident[EI_DATA] == ELFDATA2LSB \
&& BYTE_ORDER == BIG_ENDIAN)) \
&& sizeof (val) != 1) \
{ \
if (sizeof (val) == 2) \
__res = bswap_16 (val); \
else if (sizeof (val) == 4) \
__res = bswap_32 (val); \
else \
__res = bswap_64 (val); \
} \
else \
__res = (val); \
__res; })
static int
AB(handle_file) (const char *fname, int fd)
{
E(Ehdr) ehdr;
if (pread (fd, &ehdr, sizeof (ehdr), 0) != sizeof (ehdr))
{
read_error:
printf ("%s: read error: %m\n", fname);
return 1;
}
const size_t phnum = SWAP (ehdr.e_phnum);
const size_t phentsize = SWAP (ehdr.e_phentsize);
/* Read the program header. */
E(Phdr) *phdr = alloca (phentsize * phnum);
if (pread (fd, phdr, phentsize * phnum, SWAP (ehdr.e_phoff))
!= phentsize * phnum)
goto read_error;
/* Search for the PT_GNU_STACK entry. */
for (size_t cnt = 0; cnt < phnum; ++cnt)
if (SWAP (phdr[cnt].p_type) == PT_GNU_STACK)
{
unsigned int flags = SWAP(phdr[cnt].p_flags);
if (flags & PF_X)
{
printf ("%s: executable stack signaled\n", fname);
return 1;
}
return 0;
}
printf ("%s: no PT_GNU_STACK entry\n", fname);
return 1;
}
# undef BITS
#else
# define BITS 32
# include "check-execstack.c"
# define BITS 64
# include "check-execstack.c"
static int
handle_file (const char *fname)
{
int fd = open (fname, O_RDONLY);
if (fd == -1)
{
printf ("cannot open %s: %m\n", fname);
return 1;
}
/* Read was is supposed to be the ELF header. Read the initial
bytes to determine whether this is a 32 or 64 bit file. */
char ident[EI_NIDENT];
if (read (fd, ident, EI_NIDENT) != EI_NIDENT)
{
printf ("%s: read error: %m\n", fname);
close (fd);
return 1;
}
if (memcmp (&ident[EI_MAG0], ELFMAG, SELFMAG) != 0)
{
printf ("%s: not an ELF file\n", fname);
close (fd);
return 1;
}
int result;
if (ident[EI_CLASS] == ELFCLASS64)
result = handle_file64 (fname, fd);
else
result = handle_file32 (fname, fd);
close (fd);
return result;
}
int
main (int argc, char *argv[])
{
int cnt;
int result = 0;
for (cnt = 1; cnt < argc; ++cnt)
result |= handle_file (argv[cnt]);
return result;
}
#endif