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Date:      Thu, 12 Feb 2015 02:08:45 +0000 (UTC)
From:      Ed Maste <emaste@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r278611 - head/contrib/elftoolchain/libdwarf
Message-ID:  <201502120208.t1C28jbv063367@svn.freebsd.org>
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Author: emaste
Date: Thu Feb 12 02:08:44 2015
New Revision: 278611
URL: https://svnweb.freebsd.org/changeset/base/278611

Log:
  libdwarf: Handle .rel relocations
  
  Some architectures use .rel relocations (for debug data), so they must
  be handled.
  
  This was discovered from ctfconvert on ARM object files.  The lack of
  relocation handling caused all string lookups to return the string at
  offset 0 in .debug_str, typically "FreeBSD clang version ..."
  
  Reviewed by:	gnn, imp, rpaulo (earlier version)
  Sponsored by:	The FreeBSD Foundation
  Differential Revision:	https://reviews.freebsd.org/D1819

Modified:
  head/contrib/elftoolchain/libdwarf/_libdwarf.h
  head/contrib/elftoolchain/libdwarf/dwarf_reloc.c
  head/contrib/elftoolchain/libdwarf/dwarf_set_reloc_application.3
  head/contrib/elftoolchain/libdwarf/libdwarf.c
  head/contrib/elftoolchain/libdwarf/libdwarf_elf_init.c

Modified: head/contrib/elftoolchain/libdwarf/_libdwarf.h
==============================================================================
--- head/contrib/elftoolchain/libdwarf/_libdwarf.h	Thu Feb 12 00:50:54 2015	(r278610)
+++ head/contrib/elftoolchain/libdwarf/_libdwarf.h	Thu Feb 12 02:08:44 2015	(r278611)
@@ -49,7 +49,7 @@
 struct _libdwarf_globals {
 	Dwarf_Handler	errhand;
 	Dwarf_Ptr	errarg;
-	int		applyrela;
+	int		applyreloc;
 };
 
 extern struct _libdwarf_globals _libdwarf;

Modified: head/contrib/elftoolchain/libdwarf/dwarf_reloc.c
==============================================================================
--- head/contrib/elftoolchain/libdwarf/dwarf_reloc.c	Thu Feb 12 00:50:54 2015	(r278610)
+++ head/contrib/elftoolchain/libdwarf/dwarf_reloc.c	Thu Feb 12 02:08:44 2015	(r278611)
@@ -33,8 +33,8 @@ dwarf_set_reloc_application(int apply)
 {
 	int oldapply;
 
-	oldapply = _libdwarf.applyrela;
-	_libdwarf.applyrela = apply;
+	oldapply = _libdwarf.applyreloc;
+	_libdwarf.applyreloc = apply;
 
 	return (oldapply);
 }

Modified: head/contrib/elftoolchain/libdwarf/dwarf_set_reloc_application.3
==============================================================================
--- head/contrib/elftoolchain/libdwarf/dwarf_set_reloc_application.3	Thu Feb 12 00:50:54 2015	(r278610)
+++ head/contrib/elftoolchain/libdwarf/dwarf_set_reloc_application.3	Thu Feb 12 02:08:44 2015	(r278611)
@@ -24,7 +24,7 @@
 .\"
 .\" $Id: dwarf_set_reloc_application.3 2075 2011-10-27 03:47:28Z jkoshy $
 .\"
-.Dd June 26, 2011
+.Dd February 11, 2015
 .Os
 .Dt DWARF_SET_RELOC_APPLICATION 3
 .Sh NAME
@@ -47,6 +47,8 @@ handled by the DWARF(3) library.
 If the argument
 .Ar apply
 holds a non-zero value, the library will process all the relevant
+.Dq ".rel"
+and
 .Dq ".rela"
 relocation sections and will apply the relocation records found to
 their corresponding DWARF sections.

Modified: head/contrib/elftoolchain/libdwarf/libdwarf.c
==============================================================================
--- head/contrib/elftoolchain/libdwarf/libdwarf.c	Thu Feb 12 00:50:54 2015	(r278610)
+++ head/contrib/elftoolchain/libdwarf/libdwarf.c	Thu Feb 12 02:08:44 2015	(r278611)
@@ -31,5 +31,5 @@ ELFTC_VCSID("$Id: libdwarf.c 2070 2011-1
 struct _libdwarf_globals _libdwarf = {
 	.errhand	= NULL,
 	.errarg		= NULL,
-	.applyrela	= 1
+	.applyreloc	= 1
 };

Modified: head/contrib/elftoolchain/libdwarf/libdwarf_elf_init.c
==============================================================================
--- head/contrib/elftoolchain/libdwarf/libdwarf_elf_init.c	Thu Feb 12 00:50:54 2015	(r278610)
+++ head/contrib/elftoolchain/libdwarf/libdwarf_elf_init.c	Thu Feb 12 02:08:44 2015	(r278611)
@@ -50,36 +50,46 @@ static const char *debug_name[] = {
 };
 
 static void
-_dwarf_elf_apply_reloc(Dwarf_Debug dbg, void *buf, Elf_Data *rel_data,
-    Elf_Data *symtab_data, int endian)
+_dwarf_elf_write_reloc(Dwarf_Debug dbg, Elf_Data *symtab_data, int endian,
+    void *buf, uint64_t offset, GElf_Xword r_info, GElf_Sxword r_addend)
 {
-	Dwarf_Unsigned type;
-	GElf_Rela rela;
 	GElf_Sym sym;
-	size_t symndx;
-	uint64_t offset;
-	int size, j;
+	int size;
+
+	if (gelf_getsym(symtab_data, GELF_R_SYM(r_info), &sym) == NULL)
+		return;
+	if ((size = _dwarf_get_reloc_size(dbg, GELF_R_TYPE(r_info))) == 0)
+		return; /* Unknown or non-absolute relocation. */
+	if (endian == ELFDATA2MSB)
+		_dwarf_write_msb(buf, &offset, sym.st_value + r_addend, size);
+	else
+		_dwarf_write_lsb(buf, &offset, sym.st_value + r_addend, size);
+}
+
+static void
+_dwarf_elf_apply_rel_reloc(Dwarf_Debug dbg, void *buf, Elf_Data *rel_data,
+    Elf_Data *symtab_data, int endian)
+{
+	GElf_Rel rel;
+	int j;
 
 	j = 0;
-	while (gelf_getrela(rel_data, j++, &rela) != NULL) {
-		symndx = GELF_R_SYM(rela.r_info);
-		type = GELF_R_TYPE(rela.r_info);
+	while (gelf_getrel(rel_data, j++, &rel) != NULL)
+		_dwarf_elf_write_reloc(dbg, symtab_data, endian, buf,
+		     rel.r_offset, rel.r_info, 0);
+}
 
-		if (gelf_getsym(symtab_data, symndx, &sym) == NULL)
-			continue;
+static void
+_dwarf_elf_apply_rela_reloc(Dwarf_Debug dbg, void *buf, Elf_Data *rel_data,
+    Elf_Data *symtab_data, int endian)
+{
+	GElf_Rela rela;
+	int j;
 
-		offset = rela.r_offset;
-		size = _dwarf_get_reloc_size(dbg, type);
-		if (size == 0)
-			continue; /* Unknown or non-absolute relocation. */
-
-		if (endian == ELFDATA2MSB)
-			_dwarf_write_msb(buf, &offset,
-			    sym.st_value + rela.r_addend, size);
-		else
-			_dwarf_write_lsb(buf, &offset,
-			    sym.st_value + rela.r_addend, size);
-	}
+	j = 0;
+	while (gelf_getrela(rel_data, j++, &rela) != NULL)
+		_dwarf_elf_write_reloc(dbg, symtab_data, endian, buf,
+		    rela.r_offset, rela.r_info, rela.r_addend);
 }
 
 static int
@@ -108,7 +118,8 @@ _dwarf_elf_relocate(Dwarf_Debug dbg, Elf
 			return (DW_DLE_ELF);
 		}
 
-		if (sh.sh_type != SHT_RELA || sh.sh_size == 0)
+		if ((sh.sh_type != SHT_REL && sh.sh_type != SHT_RELA) ||
+		     sh.sh_size == 0)
 			continue;
 
 		if (sh.sh_info == shndx && sh.sh_link == symtab) {
@@ -129,8 +140,12 @@ _dwarf_elf_relocate(Dwarf_Debug dbg, Elf
 			}
 			memcpy(ed->ed_alloc, ed->ed_data->d_buf,
 			    ed->ed_data->d_size);
-			_dwarf_elf_apply_reloc(dbg, ed->ed_alloc, rel,
-			    symtab_data, eh.e_ident[EI_DATA]);
+			if (sh.sh_type == SHT_REL)
+				_dwarf_elf_apply_rel_reloc(dbg, ed->ed_alloc,
+				    rel, symtab_data, eh.e_ident[EI_DATA]);
+			else
+				_dwarf_elf_apply_rela_reloc(dbg, ed->ed_alloc,
+				    rel, symtab_data, eh.e_ident[EI_DATA]);
 
 			return (DW_DLE_NONE);
 		}
@@ -286,7 +301,7 @@ _dwarf_elf_init(Dwarf_Debug dbg, Elf *el
 				}
 			}
 
-			if (_libdwarf.applyrela) {
+			if (_libdwarf.applyreloc) {
 				if (_dwarf_elf_relocate(dbg, elf,
 				    &e->eo_data[j], elf_ndxscn(scn), symtab_ndx,
 				    symtab_data, error) != DW_DLE_NONE)

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