summaryrefslogtreecommitdiffstats
path: root/tests/addsections.c
diff options
context:
space:
mode:
Diffstat (limited to 'tests/addsections.c')
-rw-r--r--tests/addsections.c286
1 files changed, 286 insertions, 0 deletions
diff --git a/tests/addsections.c b/tests/addsections.c
new file mode 100644
index 00000000..66266624
--- /dev/null
+++ b/tests/addsections.c
@@ -0,0 +1,286 @@
+/* Test program for adding (more than SHN_LORESERVE) sections.
+ Copyright (C) 2018 Red Hat, Inc.
+ This file is part of elfutils.
+
+ This file is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ elfutils 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 General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include ELFUTILS_HEADER(elf)
+#include <gelf.h>
+
+
+/* shstrndx is special, might overflow into section zero header sh_link. */
+static int
+setshstrndx (Elf *elf, size_t ndx)
+{
+ printf ("setshstrndx: %zd\n", ndx);
+
+ GElf_Ehdr ehdr_mem;
+ GElf_Ehdr *ehdr = gelf_getehdr (elf, &ehdr_mem);
+ if (ehdr == NULL)
+ return -1;
+
+ if (ndx < SHN_LORESERVE)
+ ehdr->e_shstrndx = ndx;
+ else
+ {
+ ehdr->e_shstrndx = SHN_XINDEX;
+ Elf_Scn *zscn = elf_getscn (elf, 0);
+ GElf_Shdr zshdr_mem;
+ GElf_Shdr *zshdr = gelf_getshdr (zscn, &zshdr_mem);
+ if (zshdr == NULL)
+ return -1;
+ zshdr->sh_link = ndx;
+ if (gelf_update_shdr (zscn, zshdr) == 0)
+ return -1;
+ }
+
+ if (gelf_update_ehdr (elf, ehdr) == 0)
+ return -1;
+
+ return 0;
+}
+
+/* Will add nr new '.extra' sections and a new '.new_shstrtab' section
+ at the end. */
+static void
+add_sections (const char *name, size_t nr, int use_mmap)
+{
+ printf ("add_sections '%s': %zd\n", name, nr);
+
+ int fd = open (name, O_RDWR | O_BINARY);
+ if (fd < 0)
+ {
+ fprintf (stderr, "Couldn't open file '%s': %s\n",
+ name, strerror (errno));
+ exit (1);
+ }
+
+ Elf *elf = elf_begin (fd, use_mmap ? ELF_C_RDWR_MMAP : ELF_C_RDWR, NULL);
+ if (elf == NULL)
+ {
+ fprintf (stderr, "Couldn't open ELF file '%s': %s\n",
+ name, elf_errmsg (-1));
+ exit (1);
+ }
+
+ /* We will add a new shstrtab section with two new names at the end.
+ Just get the current shstrtab table and add two entries '.extra'
+ and '.new_shstrtab' at the end of the table, so all existing indexes
+ are still valid. */
+ size_t shstrndx;
+ if (elf_getshdrstrndx (elf, &shstrndx) < 0)
+ {
+ printf ("cannot get shstrndx: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ Elf_Scn *shstrtab_scn = elf_getscn (elf, shstrndx);
+ if (shstrtab_scn == NULL)
+ {
+ printf ("couldn't get shstrtab scn: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+ Elf_Data *shstrtab_data = elf_getdata (shstrtab_scn, NULL);
+ if (shstrtab_data == NULL)
+ {
+ printf ("couldn't get shstrtab data: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+ size_t new_shstrtab_size = (shstrtab_data->d_size
+ + strlen (".extra") + 1
+ + strlen (".new_shstrtab") + 1);
+ void *new_shstrtab_buf = malloc (new_shstrtab_size);
+ if (new_shstrtab_buf == NULL)
+ {
+ printf ("couldn't allocate new shstrtab data d_buf\n");
+ exit (1);
+ }
+ memcpy (new_shstrtab_buf, shstrtab_data->d_buf, shstrtab_data->d_size);
+ size_t extra_idx = shstrtab_data->d_size;
+ size_t new_shstrtab_idx = extra_idx + strlen (".extra") + 1;
+ strcpy (new_shstrtab_buf + extra_idx, ".extra");
+ strcpy (new_shstrtab_buf + new_shstrtab_idx, ".new_shstrtab");
+
+ // Add lots of .extra sections...
+ size_t cnt = 0;
+ while (cnt++ < nr)
+ {
+ Elf_Scn *scn = elf_newscn (elf);
+ if (scn == NULL)
+ {
+ printf ("cannot create .extra section (%zd): %s\n", cnt,
+ elf_errmsg (-1));
+ exit (1);
+ }
+
+ Elf_Data *data = elf_newdata (scn);
+ if (data == NULL)
+ {
+ printf ("couldn't create new section data (%zd): %s\n", cnt,
+ elf_errmsg (-1));
+ exit (1);
+ }
+
+ data->d_size = strlen ("extra") + 1;
+ data->d_buf = "extra";
+ data->d_type = ELF_T_BYTE;
+ data->d_align = 1;
+
+ GElf_Shdr shdr_mem;
+ GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
+ if (shdr == NULL)
+ {
+ printf ("cannot get header for new section (%zd): %s\n", cnt,
+ elf_errmsg (-1));
+ exit (1);
+ }
+
+ shdr->sh_type = SHT_PROGBITS;
+ shdr->sh_flags = 0;
+ shdr->sh_addr = 0;
+ shdr->sh_link = SHN_UNDEF;
+ shdr->sh_info = SHN_UNDEF;
+ shdr->sh_addralign = 1;
+ shdr->sh_entsize = 0;
+ shdr->sh_size = data->d_size;
+ shdr->sh_name = extra_idx;
+
+ if (gelf_update_shdr (scn, shdr) == 0)
+ {
+ printf ("cannot update new section header (%zd): %s\n", cnt,
+ elf_errmsg (-1));
+ exit (1);
+ }
+ }
+
+ // Create new shstrtab section.
+ Elf_Scn *new_shstrtab_scn = elf_newscn (elf);
+ if (new_shstrtab_scn == NULL)
+ {
+ printf ("cannot create new shstrtab section: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ Elf_Data *new_shstrtab_data = elf_newdata (new_shstrtab_scn);
+ if (new_shstrtab_data == NULL)
+ {
+ printf ("couldn't create new shstrtab section data: %s\n",
+ elf_errmsg (-1));
+ exit (1);
+ }
+
+ new_shstrtab_data->d_size = new_shstrtab_size;
+ new_shstrtab_data->d_buf = new_shstrtab_buf;
+ new_shstrtab_data->d_type = ELF_T_BYTE;
+ new_shstrtab_data->d_align = 1;
+
+ GElf_Shdr shdr_mem;
+ GElf_Shdr *shdr = gelf_getshdr (new_shstrtab_scn, &shdr_mem);
+ if (shdr == NULL)
+ {
+ printf ("cannot get header for new shstrtab section: %s\n",
+ elf_errmsg (-1));
+ exit (1);
+ }
+
+ shdr->sh_type = SHT_STRTAB;
+ shdr->sh_flags = 0;
+ shdr->sh_addr = 0;
+ shdr->sh_link = SHN_UNDEF;
+ shdr->sh_info = SHN_UNDEF;
+ shdr->sh_addralign = 1;
+ shdr->sh_entsize = 0;
+ shdr->sh_size = new_shstrtab_size;
+ shdr->sh_name = new_shstrtab_idx;
+
+ // Finished new shstrtab section, update the header.
+ if (gelf_update_shdr (new_shstrtab_scn, shdr) == 0)
+ {
+ printf ("cannot update new shstrtab section header: %s\n",
+ elf_errmsg (-1));
+ exit (1);
+ }
+
+ // Set it as the new shstrtab section to get the names correct.
+ size_t new_shstrndx = elf_ndxscn (new_shstrtab_scn);
+ if (setshstrndx (elf, new_shstrndx) < 0)
+ {
+ printf ("cannot set shstrndx: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ // Write everything to disk.
+ if (elf_update (elf, ELF_C_WRITE) < 0)
+ {
+ printf ("failure in elf_update: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ if (elf_end (elf) != 0)
+ {
+ printf ("couldn't cleanup elf '%s': %s\n", name, elf_errmsg (-1));
+ exit (1);
+ }
+
+ if (close (fd) != 0)
+ {
+ printf ("couldn't close '%s': %s\n", name, strerror (errno));
+ exit (1);
+ }
+
+ free (new_shstrtab_buf);
+}
+
+int
+main (int argc, char *argv[])
+{
+ elf_version (EV_CURRENT);
+
+ /* Takes the given file, and adds the given number of sections. */
+ if (argc < 3 || argc > 4)
+ {
+ fprintf (stderr, "addsections [--mmap] nr elf.file\n");
+ exit (1);
+ }
+
+ int argn = 1;
+ bool use_mmap = false;
+ if (strcmp (argv[argn], "--mmap") == 0)
+ {
+ use_mmap = true;
+ argn++;
+ }
+
+ size_t nr = atoi (argv[argn++]);
+ const char *file = argv[argn];
+ add_sections (file, nr, use_mmap);
+
+ return 0;
+}