Re: Prepare for elfutils 0.159 release

Re: Prepare for elfutils 0.159 release

[Mark Wielaard]

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On Mon, 2014-05-19 at 00:43 +0200, Mark Wielaard wrote:
> And on armv7hl with one FAIL.
> 
> We added elflint checks against .o ET_REL files which produce on arm:
> section [ 8] '.rel.ARM.exidx': invalid destination section type
>
> On RHEL5 ia64 elflint also failed with two issues:
> 
> section [13] '.rela.IA_64.unwind': invalid destination section type
> Again in an ET_REL file, so it looks like the armv7hl failure above.

They were indeed related. Both architectures add a special section type
which is the target of a relocation. elflint didn't know about the
special section type. The attached patch fixes it by introducing a new
ebl hook with implementations for arm and ia64 that elflint then calls.

> section [ 2] '.dynsym': symbol 1: symbol in dynamic symbol table with
> non-default visibility

This looks like a real bug caused by a really ancient binutils.
The .dynsym contains symbols with STV_HIDDEN. Which really is just
wrong. I don't want to add a workaround for this one.

I'll merge the attached patch and do a release tomorrow.

Cheers,

Mark


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>From 028d0ab0cc1cb5f96ee48feef966b7d8d56c6a8e Mon Sep 17 00:00:00 2001
From: Mark Wielaard <mjw@redhat.com>
Date: Mon, 19 May 2014 16:52:56 +0200
Subject: [PATCH] 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>
---
 backends/ChangeLog                                 |    7 +++
 backends/arm_init.c                                |    1 +
 backends/arm_symbol.c                              |    9 ++++-
 backends/ia64_init.c                               |    3 +-
 backends/ia64_symbol.c                             |    9 ++++-
 libebl/ChangeLog                                   |   10 +++++
 libebl/Makefile.am                                 |    2 +-
 libebl/ebl-hooks.h                                 |    5 ++-
 .../eblcheckreloctargettype.c                      |   40 +++++---------------
 libebl/eblopenbackend.c                            |   11 +++++-
 libebl/libebl.h                                    |    3 +
 src/ChangeLog                                      |    4 ++
 src/elflint.c                                      |    3 +-
 13 files changed, 69 insertions(+), 38 deletions(-)
 copy backends/ia64_init.c => libebl/eblcheckreloctargettype.c (50%)

diff --git a/backends/ChangeLog b/backends/ChangeLog
index 748d0a0..bc5b843 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 14b2635..92e6cd5 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 e41ce34..cd467ff 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 ed56efa..91da748 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 8d806b0..f928b0b 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 fc6bdd5..7198d5e 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 916af72..ec4477b 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 bfb7f4a..65c62ec 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/backends/ia64_init.c b/libebl/eblcheckreloctargettype.c
similarity index 50%
copy from backends/ia64_init.c
copy to libebl/eblcheckreloctargettype.c
index ed56efa..e135f8a 100644
--- a/backends/ia64_init.c
+++ b/libebl/eblcheckreloctargettype.c
@@ -1,7 +1,6 @@
-/* Initialization of IA-64 specific backend library.
-   Copyright (C) 2002, 2003, 2005, 2006, 2007 Red Hat, Inc.
+/* Check whether a section type is a valid target for relocation.
+   Copyright (C) 2014 Red Hat, Inc.
    This file is part of elfutils.
-   Written by Ulrich Drepper <drepper@redhat.com>, 2002.
 
    This file is free software; you can redistribute it and/or modify
    it under the terms of either
@@ -31,36 +30,17 @@
 # include <config.h>
 #endif
 
-#define BACKEND		ia64_
-#define RELOC_PREFIX	R_IA64_
-#include "libebl_CPU.h"
+#include <libeblP.h>
 
-/* This defines the common reloc hooks based on ia64_reloc.def.  */
-#include "common-reloc.c"
 
-const char *
-ia64_init (elf, machine, eh, ehlen)
-     Elf *elf __attribute__ ((unused));
-     GElf_Half machine __attribute__ ((unused));
-     Ebl *eh;
-     size_t ehlen;
+bool
+ebl_check_reloc_target_type (Ebl *ebl, Elf64_Word sh_type)
 {
-  /* Check whether the Elf_BH object has a sufficent size.  */
-  if (ehlen < sizeof (Ebl))
-    return NULL;
+  if (ebl->check_reloc_target_type (ebl, sh_type))
+    return true;
 
-  /* We handle it.  */
-  eh->name = "Intel IA-64";
-  ia64_init_reloc (eh);
-  HOOK (eh, reloc_simple_type);
-  HOOK (eh, segment_type_name);
-  HOOK (eh, section_type_name);
-  HOOK (eh, dynamic_tag_name);
-  HOOK (eh, dynamic_tag_check);
-  HOOK (eh, machine_flag_check);
-  HOOK (eh, machine_section_flag_check);
-  HOOK (eh, register_info);
-  HOOK (eh, return_value_location);
+  if (sh_type == SHT_PROGBITS || sh_type == SHT_NOBITS)
+    return true;
 
-  return MODVERSION;
+  return false;
 }
diff --git a/libebl/eblopenbackend.c b/libebl/eblopenbackend.c
index c19ae1b..bd94759 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 50d6baa..d05751f 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 341787d..4197ccd 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 5a500b7..bf6d044 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)
-- 
1.7.1

Prepare for elfutils 0.159 release

[Mark Wielaard]

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Hi,

I think we are almost ready to release 0.159. I updated the release
related files on master and merge master to the portable branch. This is
the current NEWS entry:

Version 0.159

stack: New option -d, --debugname to lookup DWARF debuginfo name for frame.
       New option -i, --inlines to show inlined frames using DWARF debuginfo.

libdwelf: New libdwelf.h header for libdw.so DWARF ELF Low-level Functions.
          New function dwelf_elf_gnu_debuglink, dwelf_dwarf_gnu_debugaltlink,
          and dwelf_elf_gnu_build_id.

libdw: Support for DWZ multifile forms DW_FORM_GNU_ref_alt and
       DW_FORM_GNU_strp_alt is now enabled by default and no longer
       experimental. Added new functions dwarf_getalt and dwarf_setalt
       to get or set the alternative debug file used for the alt FORMs.
       The dwfl_linux_proc_find_elf callback will now find ELF from
       process memory for (deleted) files if the Dwfl has process state
       attached.

libdwfl: The dwfl_build_id_find_debuginfo and dwfl_standard_find_debuginfo
         functions will now try to resolve and set the alternative debug file.

backends: Add CFI unwinding for arm. Relies on .debug_frame.
          Add arm process initial register state compatible mode to AARCH64.
          Add aarch64 native and core unwind support.

other: All separate elfutils-robustify patches have been merged.
       CVE-2014-0172 Check overflow before calling malloc to uncompress data.

Tested against fedora rawhide on aarch64, i686, x86_64, s390, s390x and
ppc64 without any FAILS. And on armv7hl with one FAIL.

We added elflint checks against .o ET_REL files which produce on arm:
section [ 8] '.rel.ARM.exidx': invalid destination section type

I'll see if I can figure out what that should be, but I don't think it
is a showstopper because it isn't really a regression.

Tested against RHEL6 on ppc, ppc64, i686, s390, s390x and x86_64 without
any FAILS.

portable branch tested against RHEL5 on ppc64, ppc, ia64, x86_64, i386,
s390 and s390x. All had one failure in the backtrace-demangle test. The
issue is that the test uses local/static functions and apparently the
mangling for that changed (the abi only defines mangling for public
functions). I have a fix for that, which I'll post and integrate before
release.

On RHEL5 ia64 elflint also failed with two issues:

section [13] '.rela.IA_64.unwind': invalid destination section type
Again in an ET_REL file, so it looks like the armv7hl failure above.

section [ 2] '.dynsym': symbol 1: symbol in dynamic symbol table with
non-default visibility
I haven't investigated this one yet.

I'll see if I can figure them out and fix them, but I don't think the
ia64 elflint issues are regressions, so they should not be showstoppers.

Please let me know if there are any regressions you want to fix before
the 0.159 release.

Thanks,

Mark