backends: Add ebl_check_reloc_target_type.

And implement for arm and ia64. Both have special section types that
are valid targets for a reloc. Both refer to unwind data. elflint now
just calls ebl_check_reloc_target_type instead of hard coding the
expected section types.

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

13 files changed, 105 insertions, 8 deletions

diff --git a/backends/ChangeLog b/backends/ChangeLog
index 748d0a06..bc5b8434 100644
--- a/backends/ChangeLog
+++ b/backends/ChangeLog
@@ -1,3 +1,10 @@
+2014-05-19  Mark Wielaard  <mjw@redhat.com>
+
+	* arm_init.c (arm_init): Hook check_reloc_target_type.
+	* arm_symbol.c (arm_check_reloc_target_type): New function.
+	* ia64_init.c (ia64_init): Hook check_reloc_target_type.
+	* ia64_symbol.c (ia64_check_reloc_target_type): New function.
+
 2014-04-22  Kurt Roeckx  <kurt@roeckx.be>
 
 	* i386_initreg.c: Make Linux only.
diff --git a/backends/arm_init.c b/backends/arm_init.c
index 14b26356..92e6cd51 100644
--- a/backends/arm_init.c
+++ b/backends/arm_init.c
@@ -63,6 +63,7 @@ arm_init (elf, machine, eh, ehlen)
   HOOK (eh, check_object_attribute);
   HOOK (eh, return_value_location);
   HOOK (eh, abi_cfi);
+  HOOK (eh, check_reloc_target_type);
 
   /* We only unwind the core integer registers.  */
   eh->frame_nregs = 16;
diff --git a/backends/arm_symbol.c b/backends/arm_symbol.c
index e41ce347..cd467ffc 100644
--- a/backends/arm_symbol.c
+++ b/backends/arm_symbol.c
@@ -1,5 +1,5 @@
 /* Arm specific symbolic name handling.
-   Copyright (C) 2002-2009 Red Hat, Inc.
+   Copyright (C) 2002-2009, 2014 Red Hat, Inc.
    This file is part of elfutils.
 
    This file is free software; you can redistribute it and/or modify
@@ -122,3 +122,10 @@ arm_reloc_simple_type (Ebl *ebl __attribute__ ((unused)), int type)
       return ELF_T_NUM;
     }
 }
+
+/* The SHT_ARM_EXIDX section type is a valid target for relocation.  */
+bool
+arm_check_reloc_target_type (Ebl *ebl __attribute__ ((unused)), Elf64_Word sh_type)
+{
+  return sh_type == SHT_ARM_EXIDX;
+}
diff --git a/backends/ia64_init.c b/backends/ia64_init.c
index ed56efaa..91da748d 100644
--- a/backends/ia64_init.c
+++ b/backends/ia64_init.c
@@ -1,5 +1,5 @@
 /* Initialization of IA-64 specific backend library.
-   Copyright (C) 2002, 2003, 2005, 2006, 2007 Red Hat, Inc.
+   Copyright (C) 2002, 2003, 2005, 2006, 2007, 2014 Red Hat, Inc.
    This file is part of elfutils.
    Written by Ulrich Drepper <drepper@redhat.com>, 2002.
 
@@ -61,6 +61,7 @@ ia64_init (elf, machine, eh, ehlen)
   HOOK (eh, machine_section_flag_check);
   HOOK (eh, register_info);
   HOOK (eh, return_value_location);
+  HOOK (eh, check_reloc_target_type);
 
   return MODVERSION;
 }
diff --git a/backends/ia64_symbol.c b/backends/ia64_symbol.c
index 8d806b02..f928b0b7 100644
--- a/backends/ia64_symbol.c
+++ b/backends/ia64_symbol.c
@@ -1,5 +1,5 @@
 /* IA-64 specific symbolic name handling.
-   Copyright (C) 2002-2009 Red Hat, Inc.
+   Copyright (C) 2002-2009, 2014 Red Hat, Inc.
    This file is part of elfutils.
    Written by Ulrich Drepper <drepper@redhat.com>, 2002.
 
@@ -148,3 +148,10 @@ ia64_reloc_simple_type (Ebl *ebl, int type)
 
   return ELF_T_NUM;
 }
+
+/* The SHT_IA_64_UNWIND section type is a valid target for relocation.  */
+bool
+ia64_check_reloc_target_type (Ebl *ebl __attribute__ ((unused)), Elf64_Word sh_type)
+{
+  return sh_type == SHT_IA_64_UNWIND;
+}
diff --git a/libebl/ChangeLog b/libebl/ChangeLog
index fc6bdd56..7198d5ec 100644
--- a/libebl/ChangeLog
+++ b/libebl/ChangeLog
@@ -1,3 +1,13 @@
+2014-05-19  Mark Wielaard  <mjw@redhat.com>
+
+	* Makefile.am (gen_SOURCES): Add eblcheckreloctargettype.c.
+	* eblcheckreloctargettype.c: New file.
+	* ebl-hooks.h (check_reloc_target_type): New hook.
+	* eblopenbackend.c (default_check_reloc_target_type): New function.
+	(fill_defaults): Assign default_check_reloc_target_type to
+	check_reloc_target_type.
+	* libebl.h (ebl_check_reloc_target_type): New function definition.
+
 2013-12-18  Mark Wielaard  <mjw@redhat.com>
 
 	* Makefile.am (gen_SOURCES): Add eblresolvesym.c.
diff --git a/libebl/Makefile.am b/libebl/Makefile.am
index 916af72a..ec4477b7 100644
--- a/libebl/Makefile.am
+++ b/libebl/Makefile.am
@@ -55,7 +55,7 @@ gen_SOURCES = eblopenbackend.c eblclosebackend.c eblstrtab.c \
 	      eblsysvhashentrysize.c eblauxvinfo.c eblcheckobjattr.c \
 	      ebl_check_special_section.c ebl_syscall_abi.c eblabicfi.c \
 	      eblstother.c eblinitreg.c ebldwarftoregno.c eblnormalizepc.c \
-	      eblunwind.c eblresolvesym.c
+	      eblunwind.c eblresolvesym.c eblcheckreloctargettype.c
 
 libebl_a_SOURCES = $(gen_SOURCES)
 
diff --git a/libebl/ebl-hooks.h b/libebl/ebl-hooks.h
index bfb7f4a9..65c62ec6 100644
--- a/libebl/ebl-hooks.h
+++ b/libebl/ebl-hooks.h
@@ -1,5 +1,5 @@
 /* Backend hook signatures internal interface for libebl.
-   Copyright (C) 2000-2011, 2013 Red Hat, Inc.
+   Copyright (C) 2000-2011, 2013, 2014 Red Hat, Inc.
    This file is part of elfutils.
 
    This file is free software; you can redistribute it and/or modify
@@ -105,6 +105,9 @@ bool EBLHOOK(object_note) (const char *, uint32_t, uint32_t, const char *);
 bool EBLHOOK(check_object_attribute) (Ebl *, const char *, int, uint64_t,
 				      const char **, const char **);
 
+/* Check reloc target section type.  */
+bool EBLHOOK(check_reloc_target_type) (Ebl *, Elf64_Word);
+
 /* Describe auxv element type.  */
 int EBLHOOK(auxv_info) (GElf_Xword, const char **, const char **);
 
diff --git a/libebl/eblcheckreloctargettype.c b/libebl/eblcheckreloctargettype.c
new file mode 100644
index 00000000..e135f8a3
--- /dev/null
+++ b/libebl/eblcheckreloctargettype.c
@@ -0,0 +1,46 @@
+/* Check whether a section type is a valid target for relocation.
+   Copyright (C) 2014 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 either
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at
+       your option) any later version
+
+   or
+
+     * the GNU General Public License as published by the Free
+       Software Foundation; either version 2 of the License, or (at
+       your option) any later version
+
+   or both in parallel, as here.
+
+   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 copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <libeblP.h>
+
+
+bool
+ebl_check_reloc_target_type (Ebl *ebl, Elf64_Word sh_type)
+{
+  if (ebl->check_reloc_target_type (ebl, sh_type))
+    return true;
+
+  if (sh_type == SHT_PROGBITS || sh_type == SHT_NOBITS)
+    return true;
+
+  return false;
+}
diff --git a/libebl/eblopenbackend.c b/libebl/eblopenbackend.c
index c19ae1b2..bd947599 100644
--- a/libebl/eblopenbackend.c
+++ b/libebl/eblopenbackend.c
@@ -1,5 +1,5 @@
 /* Generate ELF backend handle.
-   Copyright (C) 2000-2013 Red Hat, Inc.
+   Copyright (C) 2000-2014 Red Hat, Inc.
    This file is part of elfutils.
 
    This file is free software; you can redistribute it and/or modify
@@ -200,6 +200,7 @@ static bool default_check_object_attribute (Ebl *ebl, const char *vendor,
 					    int tag, uint64_t value,
 					    const char **tag_name,
 					    const char **value_name);
+static bool default_check_reloc_target_type (Ebl *ebl, Elf64_Word sh_type);
 static int default_abi_cfi (Ebl *ebl, Dwarf_CIE *abi_info);
 
 
@@ -241,6 +242,7 @@ fill_defaults (Ebl *result)
   result->register_info = default_register_info;
   result->syscall_abi = default_syscall_abi;
   result->check_object_attribute = default_check_object_attribute;
+  result->check_reloc_target_type = default_check_reloc_target_type;
   result->disasm = NULL;
   result->abi_cfi = default_abi_cfi;
   result->destr = default_destr;
@@ -747,6 +749,13 @@ default_check_object_attribute (Ebl *ebl __attribute__ ((unused)),
   return false;
 }
 
+static bool
+default_check_reloc_target_type (Ebl *ebl __attribute__ ((unused)),
+				 Elf64_Word sh_type __attribute__ ((unused)))
+{
+  return false;
+}
+
 static int
 default_abi_cfi (Ebl *ebl __attribute__ ((unused)),
 		 Dwarf_CIE *abi_info __attribute__ ((unused)))
diff --git a/libebl/libebl.h b/libebl/libebl.h
index 50d6baab..d05751fa 100644
--- a/libebl/libebl.h
+++ b/libebl/libebl.h
@@ -179,6 +179,9 @@ extern bool ebl_check_object_attribute (Ebl *ebl, const char *vendor,
 					const char **tag_name,
 					const char **value_name);
 
+/* Check whether a section type is a valid reloc target.  */
+extern bool ebl_check_reloc_target_type (Ebl *ebl, Elf64_Word sh_type);
+
 
 /* Check section name for being that of a debug informatino section.  */
 extern bool ebl_debugscn_p (Ebl *ebl, const char *name);
diff --git a/src/ChangeLog b/src/ChangeLog
index 341787d6..4197ccd9 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,7 @@
+2014-05-19  Mark Wielaard  <mjw@redhat.com>
+
+	* elflint.c (check_reloc_shdr): Check ebl_check_reloc_target_type.
+
 2014-05-01  Mark Wielaard  <mjw@redhat.com>
 
 	* readelf.c (find_no_debuginfo): Call dwfl_standard_find_debuginfo
diff --git a/src/elflint.c b/src/elflint.c
index 5a500b76..bf6d044b 100644
--- a/src/elflint.c
+++ b/src/elflint.c
@@ -1216,8 +1216,7 @@ check_reloc_shdr (Ebl *ebl, const GElf_Ehdr *ehdr, const GElf_Shdr *shdr,
 				 destshdr_memp);
       if (*destshdrp != NULL)
 	{
-	  if((*destshdrp)->sh_type != SHT_PROGBITS
-	     && (*destshdrp)->sh_type != SHT_NOBITS)
+	  if(! ebl_check_reloc_target_type (ebl, (*destshdrp)->sh_type))
 	    {
 	      reldyn = is_rel_dyn (ebl, ehdr, idx, shdr, true);
 	      if (!reldyn)