libelf: Always update e_version and e_shentsize in elf_update.

When e_version is EV_NONE we should set it to EV_CURRENT like we do for
the EI_VERSION and like we set EI_DATA to the correct byte order when set
to ELFDATANONE.  Likewise we should always set e_shentsize like we do for
e_phentsize, not just when ELF_F_LAYOUT isn't set.

Add a new elfshphehdr testcase to check the above.

Signed-off-by: Mark Wielaard <mjw@redhat.com>

1 files changed, 182 insertions, 0 deletions

diff --git a/tests/elfshphehdr.c b/tests/elfshphehdr.c
new file mode 100644
index 00000000..5f6b96c9
--- /dev/null
+++ b/tests/elfshphehdr.c
@@ -0,0 +1,182 @@
+/* Test program for adding section and program headers and ehdr updates.
+   Copyright (C) 2015 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/>.  */
+
+#include <config.h>
+#include <assert.h>
+#include ELFUTILS_HEADER(elf)
+#include <gelf.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include <stdbool.h>
+
+void
+check (const char *msg, bool check)
+{
+  if (! check)
+    {
+      fprintf (stderr, "%s FAILED\n", msg);
+      exit (-1);
+    }
+  else
+    fprintf (stderr, "%s OK\n", msg);
+}
+
+void
+check_elf (const char *msg, bool check)
+{
+  if (! check)
+    {
+      fprintf (stderr, "%s: %s\n", msg, elf_errmsg (-1));
+      exit (-1);
+    }
+  else
+    fprintf (stderr, "%s OK\n", msg);
+}
+
+void
+test (Elf *elf, int class, bool layout)
+{
+  fprintf (stderr, "testing ELF class: %d, layout: %d\n", class, layout);
+
+  check_elf ("gelf_newehdr", gelf_newehdr (elf, class) != 0);
+  check_elf ("gelf_getclass", gelf_getclass (elf) == class);
+
+  check_elf ("elf_flagelf", elf_flagelf (elf, layout ? ELF_C_SET : ELF_C_CLR,
+					 ELF_F_LAYOUT) != 0);
+
+  GElf_Ehdr ehdr;
+  check_elf ("gelf_getehdr", gelf_getehdr (elf, &ehdr) != NULL);
+  check ("e_shnum == 0", ehdr.e_shnum == 0);
+  check ("e_phnum == 0", ehdr.e_phnum == 0);
+  check ("e_shoff == 0", ehdr.e_shoff == 0);
+  check ("e_phoff == 0", ehdr.e_phoff == 0);
+
+  size_t shnum;
+  check_elf ("elf_getshdrnum", elf_getshdrnum (elf, &shnum) == 0);
+  check ("shnum == 0", shnum == 0);
+
+  size_t phnum;
+  check_elf ("elf_getphdrnum", elf_getphdrnum (elf, &phnum) == 0);
+  check ("phnum == 0", phnum == 0);
+
+  /* Lets fill in some info we are always responsible for.  */
+  ehdr.e_ident[EI_DATA] = ELFDATANONE; /* Ask for native encoding.  */
+  ehdr.e_type = ET_EXEC;
+  ehdr.e_machine = EM_386;
+  ehdr.e_version = EV_NONE; /* Ask for current version. */
+  check_elf ("gelf_update_ehdr", gelf_update_ehdr (elf, &ehdr) != 0);
+
+  check_elf ("elf_update", elf_update (elf, ELF_C_NULL) > 0);
+
+  check_elf ("gelf_getehdr", gelf_getehdr (elf, &ehdr) != NULL);
+  check ("EI_DATA", ehdr.e_ident[EI_DATA] != ELFDATANONE);
+  check ("e_version", ehdr.e_version == EV_CURRENT);
+
+  /* The sh/ph values shouldn't have changed.  */
+  check ("e_shnum == 0", ehdr.e_shnum == 0);
+  check ("e_phnum == 0", ehdr.e_phnum == 0);
+  check ("e_shoff == 0", ehdr.e_shoff == 0);
+  check ("e_phoff == 0", ehdr.e_phoff == 0);
+
+  check_elf ("elf_getshdrnum", elf_getshdrnum (elf, &shnum) == 0);
+  check ("shnum == 0", shnum == 0);
+
+  check_elf ("elf_getphdrnum", elf_getphdrnum (elf, &phnum) == 0);
+  check ("phnum == 0", phnum == 0);
+
+  /* Lets add a header.  */
+  check_elf ("elf_newscn", elf_newscn (elf) != NULL);
+  check_elf ("gelf_newphdr", gelf_newphdr (elf, 1) != 0);
+
+  /* If we are responsible for the layout ourselves we should also
+     tell where to put them.  */
+  if (layout)
+    {
+      check_elf ("gelf_getehdr", gelf_getehdr (elf, &ehdr) != NULL);
+      /* phdrs go right after the ehdr.  */
+      ehdr.e_phoff = ehdr.e_ehsize;
+      /* shdrs go right after the phdrs.  */
+      ehdr.e_shoff = ehdr.e_phoff + ehdr.e_phnum * ehdr.e_phentsize;
+      check_elf ("gelf_update_ehdr", gelf_update_ehdr (elf, &ehdr) != 0);
+    }
+
+  check_elf ("elf_update", elf_update (elf, ELF_C_NULL) > 0);
+
+  check_elf ("elf_getshdrnum", elf_getshdrnum (elf, &shnum) == 0);
+  check ("shnum == 1", shnum == 2); /* section zero is also created.  */
+
+  check_elf ("elf_getphdrnum", elf_getphdrnum (elf, &phnum) != 0);
+  check ("phnum == 1", phnum == 1);
+
+  check_elf ("gelf_getehdr", gelf_getehdr (elf, &ehdr) != NULL);
+
+  check ("EI_DATA", ehdr.e_ident[EI_DATA] != ELFDATANONE);
+  check ("e_version", ehdr.e_version == EV_CURRENT);
+
+  check ("e_shnum == 2", ehdr.e_shnum == 2);
+  check ("e_phnum == 1", ehdr.e_phnum == 1);
+  check ("e_shoff != 0", ehdr.e_shoff != 0);
+  check ("e_phoff != 0", ehdr.e_phoff != 0);
+
+  size_t shentsize = (class == ELFCLASS32
+		      ? sizeof (Elf32_Shdr) : sizeof (Elf64_Shdr));
+  check ("e_shentsize", ehdr.e_shentsize == shentsize);
+  size_t phentsize = (class == ELFCLASS32
+		      ? sizeof (Elf32_Phdr) : sizeof (Elf64_Phdr));
+  check ("e_phentsize", ehdr.e_phentsize == phentsize);
+}
+
+int
+main (int argc __attribute__ ((unused)), char **argv __attribute ((unused)))
+{
+  elf_version (EV_CURRENT);
+
+  int fd = fd = open("/dev/zero", O_WRONLY);
+  check ("open", fd >= 0);
+
+  Elf *elf;
+
+  elf = elf_begin (fd, ELF_C_WRITE, NULL);
+  check_elf ("elf_begin", elf != NULL);
+  test (elf, ELFCLASS32, false);
+  elf_end (elf);
+
+  elf = elf_begin (fd, ELF_C_WRITE, NULL);
+  check_elf ("elf_begin", elf != NULL);
+  test (elf, ELFCLASS32, true);
+  elf_end (elf);
+
+  elf = elf_begin (fd, ELF_C_WRITE, NULL);
+  check_elf ("elf_begin", elf != NULL);
+  test (elf, ELFCLASS64, false);
+  elf_end (elf);
+
+  elf = elf_begin (fd, ELF_C_WRITE, NULL);
+  check_elf ("elf_begin", elf != NULL);
+  test (elf, ELFCLASS64, true);
+  elf_end (elf);
+
+  close (fd);
+  return 0;
+}