aboutsummaryrefslogtreecommitdiff
path: root/elf/check-textrel.c
diff options
context:
space:
mode:
authorRoland McGrath <roland@hack.frob.com>2012-04-30 15:00:14 -0700
committerRoland McGrath <roland@hack.frob.com>2012-05-01 13:27:11 -0700
commit82a79e7d1843f9d90075a0bf2f04557040829bb0 (patch)
tree063a8edbad83c421ddc11bd1b1238143378eb900 /elf/check-textrel.c
parent615605c94eb3238fa1a0721506d70871f1610967 (diff)
downloadglibc-82a79e7d1843f9d90075a0bf2f04557040829bb0.zip
glibc-82a79e7d1843f9d90075a0bf2f04557040829bb0.tar.gz
glibc-82a79e7d1843f9d90075a0bf2f04557040829bb0.tar.bz2
Do check-textrel test using readelf rather than a build-time C program.
Diffstat (limited to 'elf/check-textrel.c')
-rw-r--r--elf/check-textrel.c198
1 files changed, 0 insertions, 198 deletions
diff --git a/elf/check-textrel.c b/elf/check-textrel.c
deleted file mode 100644
index 6372019..0000000
--- a/elf/check-textrel.c
+++ /dev/null
@@ -1,198 +0,0 @@
-/* Check for text relocations in DSOs.
- Copyright (C) 2002, 2003, 2006 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
- Contribute by Ulrich Drepper <drepper@redhat.com>. 2002.
-
- 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, see
- <http://www.gnu.org/licenses/>. */
-
-#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_DYNAMIC entry. */
- size_t cnt;
- E(Phdr) *dynphdr = NULL;
- for (cnt = 0; cnt < phnum; ++cnt)
- if (SWAP (phdr[cnt].p_type) == PT_DYNAMIC)
- dynphdr = &phdr[cnt];
- else if (SWAP (phdr[cnt].p_type) == PT_LOAD
- && (SWAP (phdr[cnt].p_flags) & (PF_X | PF_W)) == (PF_X | PF_W))
- {
- printf ("%s: segment %zu is executable and writable\n",
- fname, cnt);
-#if !defined __sparc__ \
- && !defined __alpha__ \
- && (!defined __powerpc__ || defined __powerpc64__ || defined HAVE_PPC_SECURE_PLT)
- /* sparc, sparc64, alpha and powerpc32 (the last one only when using
- -mbss-plt) are expected to have PF_X | PF_W segment containing .plt
- section, it is part of their ABI. It is bad security wise, nevertheless
- this test shouldn't fail because of this. */
- return 1;
-#endif
- }
-
- if (dynphdr == NULL)
- {
- printf ("%s: no DYNAMIC segment found\n", fname);
- return 1;
- }
-
- /* Read the dynamic segment. */
- size_t pmemsz = SWAP(dynphdr->p_memsz);
- E(Dyn) *dyn = alloca (pmemsz);
- if (pread (fd, dyn, pmemsz, SWAP(dynphdr->p_offset)) != pmemsz)
- goto read_error;
-
- /* Search for an DT_TEXTREL entry of DT_FLAGS with the DF_TEXTREL
- bit set. */
- for (cnt = 0; (cnt + 1) * sizeof (E(Dyn)) - 1 < pmemsz; ++cnt)
- {
- unsigned int tag = SWAP (dyn[cnt].d_tag);
-
- if (tag == DT_NULL)
- /* We reached the end. */
- break;
-
- if (tag == DT_TEXTREL
- || (tag == DT_FLAGS
- && (SWAP (dyn[cnt].d_un.d_val) & DF_TEXTREL) != 0))
- {
- /* Urgh! The DSO has text relocations. */
- printf ("%s: text relocations used\n", fname);
- return 1;
- }
- }
-
- printf ("%s: OK\n", fname);
-
- return 0;
-}
-
-# undef BITS
-#else
-
-# define BITS 32
-# include "check-textrel.c"
-
-# define BITS 64
-# include "check-textrel.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