Fw: [PATCH] Gold: Added R_ARM_GOT_PREL relocation and unit tests

[Viktor Kutuzov <vkutuzov@accesssoftek.com>]

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Ping.

Best regards,
Viktor
 
----- Original Message ----- 
From: "Viktor Kutuzov" <vkutuzov@accesssoftek.com>
To: <binutils@sourceware.org>
Sent: Tuesday, September 15, 2009 5:23 PM
Subject: [PATCH] Gold: Added R_ARM_GOT_PREL relocation and unit tests


Hello everyone,

Please find attached the patch for R_ARM_GOT_PREL relocation along with the unit tests.

Best regards,
Viktor

* gold/arm.cc: Added R_ARM_GOT_PREL relocation, added missing R_ARM_ABS8 in to the list of implemented relocations
* gold/testsuite/arm/Makefile.am: Added unit tests to make
* gold/testsuite/arm/reloc_got_test.sh: Script to test platform-dependent R_ARM_GOT_PREL relocation
* gold/testsuite/arm/arm_r_got_prel.s: Asm for the R_ARM_GOT_PREL relocation unit tests

[-- Attachment #2: binutil-gold-arm-rel-gotprel.diff --]
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diff -rupN -x .deps -x autom4te.cache -x configure -x 'config.*' -x Makefile -x Makefile.in -x '*~' binutils.orig/src/gold/arm.cc binutils.gold/src/gold/arm.cc
--- binutils.orig/src/gold/arm.cc	2009-09-15 15:40:09.000000000 -0700
+++ binutils.gold/src/gold/arm.cc	2009-09-15 16:48:49.000000000 -0700
@@ -68,11 +68,13 @@ class Output_data_plt_arm;
 // R_ARM_RELATIVE
 // R_ARM_GOTOFF32
 // R_ARM_GOT_BREL
+// R_ARM_GOT_PREL
 // R_ARM_PLT32
 // R_ARM_CALL
 // R_ARM_JUMP24
 // R_ARM_TARGET1
 // R_ARM_PREL31
+// R_ARM_ABS8
 // 
 // TODOs:
 // - Generate various branch stubs.
@@ -679,6 +681,16 @@ class Arm_relocate_functions : public Re
     return This::STATUS_OKAY;
   }
 
+  // R_ARM_GOT_PREL: GOT(S) + A – P
+  static inline typename This::Status
+  got_prel(unsigned char* view,
+	   typename elfcpp::Swap<32, big_endian>::Valtype got_offset,
+	   elfcpp::Elf_types<32>::Elf_Addr address)
+  {
+    Base::rel32(view, got_offset - address);
+    return This::STATUS_OKAY;
+  }
+
   // R_ARM_PLT32: (S + A) | T - P
   static inline typename This::Status
   plt32(unsigned char *view,
@@ -1156,6 +1168,7 @@ Target_arm<big_endian>::Scan::local(cons
       break;
 
     case elfcpp::R_ARM_GOT_BREL:
+    case elfcpp::R_ARM_GOT_PREL:
       {
 	// The symbol requires a GOT entry.
 	Output_data_got<32, big_endian>* got =
@@ -1351,6 +1364,7 @@ Target_arm<big_endian>::Scan::global(con
       break;
       
     case elfcpp::R_ARM_GOT_BREL:
+    case elfcpp::R_ARM_GOT_PREL:
       {
 	// The symbol requires a GOT entry.
 	Output_data_got<32, big_endian>* got =
@@ -1623,6 +1637,7 @@ Target_arm<big_endian>::Relocate::reloca
   switch (r_type)
     {
     case elfcpp::R_ARM_GOT_BREL:
+    case elfcpp::R_ARM_GOT_PREL:
       if (gsym != NULL)
 	{
 	  gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
@@ -1708,6 +1723,15 @@ Target_arm<big_endian>::Relocate::reloca
       reloc_status = Arm_relocate_functions::got_brel(view, got_offset);
       break;
 
+    case elfcpp::R_ARM_GOT_PREL:
+      gold_assert(have_got_offset);
+      // Get the address origin for GOT PLT, which is allocated right after the GOT section,
+      // to calculate an absolute address of the symbol GOT entry (got_origin + got_offset).
+      elfcpp::Elf_types<32>::Elf_Addr got_origin;
+      got_origin = target->got_plt_section()->address();
+      reloc_status = Arm_relocate_functions::got_prel(view, got_origin + got_offset, address);
+      break;
+
     case elfcpp::R_ARM_PLT32:
       gold_assert(gsym == NULL
 		  || gsym->has_plt_offset()
@@ -1835,6 +1859,7 @@ Target_arm<big_endian>::Relocatable_size
     case elfcpp::R_ARM_GOTOFF32:
     case elfcpp::R_ARM_BASE_PREL:
     case elfcpp::R_ARM_GOT_BREL:
+    case elfcpp::R_ARM_GOT_PREL:
     case elfcpp::R_ARM_PLT32:
     case elfcpp::R_ARM_CALL:
     case elfcpp::R_ARM_JUMP24:
diff -rupN -x .deps -x autom4te.cache -x configure -x 'config.*' -x Makefile -x Makefile.in -x '*~' binutils.orig/src/gold/testsuite/arm/arm_r_got_prel.s binutils.gold/src/gold/testsuite/arm/arm_r_got_prel.s
--- binutils.orig/src/gold/testsuite/arm/arm_r_got_prel.s	1969-12-31 16:00:00.000000000 -0800
+++ binutils.gold/src/gold/testsuite/arm/arm_r_got_prel.s	2009-09-15 16:25:03.000000000 -0700
@@ -0,0 +1,60 @@
+@FILE: arm_r_got_prel.s
+@TEST RELOCATION : R_ARM_GOT_PREL
+@Local static relocation
+
+@COMPILE: arm-none-linux-gnueabi-gcc arm_r_got_prel.s arm_r_got_prel.o
+@LINK:    ../binutils.gold/src/gold/ld-new arm_r_got_prel.o -o arm_r_got_prel
+
+	.cpu arm10tdmi
+	.file	"arm_r_got_prel.s"
+	.text
+	.align	2
+start:
+	.global	start
+.LCFI2:
+	ldr	r4, .L3
+.LPIC0:
+	add	r4, pc, r4		@ r4 will contain the GOT pointer 
+					@ after this.
+
+	@----------------------------------------------------
+	@ printf _global_string_got_prel
+
+	ldr	r3, .LL0		@ Loading statically relocated value 
+					@ -- an offset to GOT entry from 
+					@ the relocation address
+	add	r3, r3, #(.LL0-.LOFF1)  @ Building an absolute address to 
+					@ the GOT entry (pc + off_to_word +
+					@ off_to_GOT)
+	ldr	r3, [pc, r3]		@ Loading a value of the GOT entry
+	ldr	r3, [r3, #0]		@ Loading a pointer to the destination
+					@ string.
+.LOFF1:	mov	r0, r3
+	@bl	printf(PLT)		@ kind of printing
+
+	@----------------------------------------------------
+	.align	2
+.L3:
+	.word	_GLOBAL_OFFSET_TABLE_-(.LPIC0+8)
+REL_PREL_ADDRESS:
+	@ NOTE: put this variable into the symbol table to use in the tests.
+	.global	REL_PREL_ADDRESS
+	@ NOTE: TARGET2 relocation will be interpreted as GOT_PREL by GOLD
+.LL0:	.word   _global_string_got_prel(TARGET2)
+
+	.global	_global_string_got_prel
+
+	@----------------------------------------------------
+	.section	.rodata
+	.align	2
+.LC0:
+	.ascii  "GLOBAL (TARGET2/R_ARM_GOT_PREL).\012\000"
+
+	@----------------------------------------------------
+	.section	.data.rel.local,"aw",%progbits
+	.align	2
+_global_string_got_prel:
+	.word	.LC0
+
+	@----------------------------------------------------
+	.end
diff -rupN -x .deps -x autom4te.cache -x configure -x 'config.*' -x Makefile -x Makefile.in -x '*~' binutils.orig/src/gold/testsuite/arm/Makefile.am binutils.gold/src/gold/testsuite/arm/Makefile.am
--- binutils.orig/src/gold/testsuite/arm/Makefile.am	2009-09-15 15:40:44.000000000 -0700
+++ binutils.gold/src/gold/testsuite/arm/Makefile.am	2009-09-15 14:26:53.000000000 -0700
@@ -55,22 +55,25 @@ if TARGET_ARM
 
 # Test - ABS relocations
 
-MOSTLYCLEANFILES += arm_r_abs8_local arm_r_abs8_localrw arm_r_abs8_external
+MOSTLYCLEANFILES += arm_r_abs8_local arm_r_abs8_localrw arm_r_abs8_external arm_r_got_prel
 
 BUILT_SOURCES += \
 	arm_r_abs8_local.s \
 	arm_r_abs8_localrw.s \
 	arm_r_abs8_global.s \
-	arm_r_abs8_external.s
+	arm_r_abs8_external.s \
+	arm_r_got_prel.s
 
 check_DATA += \
 	arm_r_abs8_local \
 	arm_r_abs8_external \
 	arm_r_abs8_localrw \
-	arm_r_abs8_localoverflow.o
+	arm_r_abs8_localoverflow.o \
+	arm_r_got_prel
 
 check_SCRIPTS += \
-	reloc_abs_test.sh
+	reloc_abs_test.sh \
+	reloc_got_test.sh
 
 arm_r_abs8_local.o: arm_r_abs8_local.s
 	$(TEST_AS) -o $@ $<
@@ -82,6 +85,8 @@ arm_r_abs8_global.o: arm_r_abs8_global.s
 	$(TEST_AS) -o $@ $<
 arm_r_abs8_external.o: arm_r_abs8_external.s
 	$(TEST_AS) -o $@ $<
+arm_r_got_prel.o: arm_r_got_prel.s
+	$(TEST_AS) -o $@ $<
 
 arm_r_abs8_local: arm_r_abs8_local.o
 	$(TEST_LD) -Ttext=0 -o $@ $<
@@ -89,6 +94,8 @@ arm_r_abs8_localrw: arm_r_abs8_localrw.o
 	$(TEST_LD) -Ttext=0 -Tdata=0x90 -o $@ $<
 arm_r_abs8_external: arm_r_abs8_external.o arm_r_abs8_global.o
 	$(TEST_LD) -Ttext=0 -o $@ $< arm_r_abs8_global.o
+arm_r_got_prel: arm_r_got_prel.o
+	$(TEST_LD) -o $@ $<
 
 endif TARGET_ARM
 
diff -rupN -x .deps -x autom4te.cache -x configure -x 'config.*' -x Makefile -x Makefile.in -x '*~' binutils.orig/src/gold/testsuite/arm/reloc_got_test.sh binutils.gold/src/gold/testsuite/arm/reloc_got_test.sh
--- binutils.orig/src/gold/testsuite/arm/reloc_got_test.sh	1969-12-31 16:00:00.000000000 -0800
+++ binutils.gold/src/gold/testsuite/arm/reloc_got_test.sh	2009-09-15 16:27:25.000000000 -0700
@@ -0,0 +1,88 @@
+#!/bin/sh
+
+# reloc_got_test.sh -- a test case for the GOT relocations.
+
+# Copyright 2009 Free Software Foundation, Inc.
+# Written by Viktor Kutuzov <vkutuzov@accesssoftek.com>.
+
+# This file is a part of gold.
+
+# This program 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.
+
+# This program 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, write to the Free Software
+# Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+# MA 02110-1301, USA.
+
+check_relocation_got_prel_value()
+{
+  # Arguments: 
+  #  $1 - Linked file name. The file with the same name and extention '.o'
+  #       will be looked for objects.
+  file_name=$1
+  #  $2 - Symbol name. The relocation to test is referenced by this unique
+  #       symbol name.
+  symbol_name=$2
+  #  $3 - Symbol name. The relocation reference within the .text section
+  symbol_reloc_name=$3
+
+
+  # Retrieve the requested segment address from the linked file.
+  # The value is in the readelf output dump looks something like this:
+  # ----------------------------vvvvvvvv--------------------------------
+  # Section Headers:
+  #   [Nr] Name      Type       Addr     Off    Size   ES Flg Lk Inf Al
+  #   [ 4] .got      PROGBITS   000090c0 0000c0 000010 00  WA  0   0  4
+  valid_result=`readelf -S $file_name | grep -w ".got" | sed 's/\]//;s/\[//;s/^/:/;s/$/:/;s/[: ][: ]*/:/g' | cut -d: -f5`
+  if test -z "$valid_result"; then
+    echo "Did not find segment .got in $file_name"
+    exit 1
+  fi
+
+  symbol_reloc_address=`readelf -s $file_name | grep -w $symbol_reloc_name | sed 's/^/:/;s/$/:/;s/[: ][: ]*/:/g' | cut -d: -f3 | sed 's/^0*//g'` 
+  if test -z "$symbol_reloc_address"; then
+    echo "Did not find symbol $symbol_reloc_name in $file_name"
+    exit 1
+  fi
+
+  # Result transformation from string like "76:	90          	.byte	0x90" 
+  # to "76:90:.byte:0x90"
+  linker_result=`../../../binutils/objdump -ds $file_name | sed -e 's/^\s*//g' -e 's/^0*//g' | grep "^$symbol_reloc_address:" | sed -e 's/://' -e 's/\t/:/g' -e 's/\s//g' | cut -d: -f2`
+
+  # Add the symbol relocation address to the relocated value. We will get 
+  # a pointer (address) to the GOT entry as result.
+  # This entry has been placed at beginning of the table, because we have 
+  # only one entry in GOT. In that way an address of GOT must be equal with 
+  # an address of the entry (see $valid_result)
+  linker_result=$((0x$linker_result + 0x$symbol_reloc_address))
+  valid_result=$((0x$valid_result + 0))
+
+  #echo "debug: valid_result=$valid_result"
+  #echo "debug: symbol_reloc_address=$symbol_reloc_address"
+  #echo "debug: linked_result=$linker_result"
+
+  if test $linker_result != $valid_result; then
+    echo "check_relocation_abs_global: unexpected result for relocation value in $file_name:"
+    echo "   $valid_result"
+    echo ""
+    echo "Actual value below:"
+    echo "$linker_result"
+    exit 1
+  fi
+}
+
+
+# Unit tests:
+
+check_relocation_got_prel_value arm_r_got_prel "_global_string_got_prel" "REL_PREL_ADDRESS"
+
+exit 0
+