Re: gold script handling of program headers

[Ian Lance Taylor <iant at google dot com>]

David Miller <davem@davemloft.net> writes:

> So the resulting offset is 0x403f50, and this is where the bogus
> non-zero this->offset() seen by Output_file_header::do_write() seems
> to come from.


Thanks for the bug report.  I committed this patch, which should fix
this problem.

Ian


2008-04-15  Ian Lance Taylor  <iant@google.com>

	* script-sections.cc (Script_sections::create_segments): Use
	header_size_adjustment even when there is enough room for the
	headers.
	* testsuite/script_test_4.sh: New file.
	* testsuite/script_test_4.t: New file.
	* testsuite/Makefile.am (check_SCRIPTS): Add script_test_4.sh.
	(check_DATA): Add script_test_4.stdout.
	(MOSTLYCLEANFILES): Likewise.
	(script_test_4): New target.
	(script_test_4.stdout): New target.
	* testsuite/Makefile.in: Rebuild.


Index: script-sections.cc
===================================================================
RCS file: /cvs/src/src/gold/script-sections.cc,v
retrieving revision 1.12
diff -p -u -r1.12 script-sections.cc
--- script-sections.cc	10 Apr 2008 01:02:46 -0000	1.12
+++ script-sections.cc	15 Apr 2008 22:48:17 -0000
@@ -2706,18 +2706,17 @@ Script_sections::create_segments(Layout*
 
   size_t sizeof_headers = this->total_header_size(layout);
 
-  if ((first_seg->paddr() & (abi_pagesize - 1)) >= sizeof_headers)
-    {
-      first_seg->set_addresses(first_seg->vaddr() - sizeof_headers,
-			       first_seg->paddr() - sizeof_headers);
-      return first_seg;
-    }
-
   uint64_t vma = first_seg->vaddr();
   uint64_t lma = first_seg->paddr();
 
   uint64_t subtract = this->header_size_adjustment(lma, sizeof_headers);
 
+  if ((lma & (abi_pagesize - 1)) >= sizeof_headers)
+    {
+      first_seg->set_addresses(vma - subtract, lma - subtract);
+      return first_seg;
+    }
+
   // If there is no room to squeeze in the headers, then punt.  The
   // resulting executable probably won't run on GNU/Linux, but we
   // trust that the user knows what they are doing.
Index: testsuite/Makefile.am
===================================================================
RCS file: /cvs/src/src/gold/testsuite/Makefile.am,v
retrieving revision 1.61
diff -p -u -r1.61 Makefile.am
--- testsuite/Makefile.am	11 Apr 2008 21:24:30 -0000	1.61
+++ testsuite/Makefile.am	15 Apr 2008 22:48:17 -0000
@@ -734,5 +734,13 @@ script_test_3: basic_test.o gcctestdir/l
 script_test_3.stdout: script_test_3
 	$(TEST_READELF) -SlW script_test_3 > script_test_3.stdout
 
+check_SCRIPTS += script_test_4.sh
+check_DATA += script_test_4.stdout
+MOSTLYCLEANFILES += script_test_4.stdout
+script_test_4: basic_test.o gcctestdir/ld $(srcdir)/script_test_4.t
+	$(CXXLINK) -Bgcctestdir/ basic_test.o -T $(srcdir)/script_test_4.t
+script_test_4.stdout: script_test_4
+	$(TEST_READELF) -SlW script_test_4 > script_test_4.stdout
+
 endif GCC
 endif NATIVE_LINKER
Index: testsuite/script_test_4.sh
===================================================================
RCS file: testsuite/script_test_4.sh
diff -N testsuite/script_test_4.sh
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ testsuite/script_test_4.sh	15 Apr 2008 22:48:18 -0000
@@ -0,0 +1,41 @@
+#!/bin/sh
+
+# script_test_4.sh -- test load segment
+
+# Copyright 2008 Free Software Foundation, Inc.
+# Written by Ian Lance Taylor <iant@google.com>.
+
+# This file is 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.
+
+# This file goes with script_test_4.t, which is a linker script which
+# starts the program at an unaligned address.
+
+check()
+{
+    if ! grep -q "$2" "$1"
+    then
+	echo "Did not find expected segment in $1:"
+	echo "   $2"
+	echo ""
+	echo "Actual output below:"
+	cat "$1"
+	exit 1
+    fi
+}
+
+check script_test_4.stdout "\\.interp[ 	]*PROGBITS[ 	]*10000400"
Index: testsuite/script_test_4.t
===================================================================
RCS file: testsuite/script_test_4.t
diff -N testsuite/script_test_4.t
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ testsuite/script_test_4.t	15 Apr 2008 22:48:18 -0000
@@ -0,0 +1,40 @@
+/* script_test_4.t -- linker script test 4 for gold
+
+   Copyright 2008 Free Software Foundation, Inc.
+   Written by Ian Lance Taylor <iant@google.com>.
+
+   This file is 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.  */
+
+/* We won't try to run this program, just ensure that it links
+   as expected.  */
+
+SECTIONS
+{
+  . = 0x10000400;
+
+  /* With luck this will be enough to get the program working.  */
+  .interp : { *(.interp) }
+  .text : { *(.text) }
+  . += 0x100000;
+  . = ALIGN(0x100);
+  .dynamic : { *(.dynamic) }
+  .data : { *(.data) }
+  . += 0x100000;
+  . = ALIGN(0x100);
+  .bss : { *(.bss) }
+}