[PATCH] Use signed data type for R_XTENSA_DIFF* relocation offsets.
Max Filippov
jcmvbkbc@gmail.com
Tue May 6 22:35:00 GMT 2014
From: Volodymyr Arbatov <arbatov@cadence.com>
R_XTENSA_DIFF relocation offsets are in fact signed. Treat them as such.
Add testcase that examines ld behaviour on R_XTENSA_DIFF relocation
changing sign during relaxation.
2014-05-02 Volodymyr Arbatov <arbatov@cadence.com>
David Weatherford <weath@cadence.com>
Max Filippov <jcmvbkbc@gmail.com>
bfd/
* elf32-xtensa.c (relax_section): treat R_XTENSA_DIFF* relocations as
signed.
gas/
* config/tc-xtensa.c (md_apply_fix): mark BFD_RELOC_XTENSA_DIFF*
fixups as signed.
ld/testsuite/
* ld-xtensa/diff_overflow.exp, * ld-xtensa/diff_overflow1.s,
* ld-xtensa/diff_overflow2.s: Add test for DIFF* relocation
signedness and overflow checking.
---
bfd/elf32-xtensa.c | 32 ++++++++++++-----------
gas/config/tc-xtensa.c | 3 +++
ld/testsuite/ld-xtensa/diff_overflow.exp | 45 ++++++++++++++++++++++++++++++++
ld/testsuite/ld-xtensa/diff_overflow1.s | 27 +++++++++++++++++++
ld/testsuite/ld-xtensa/diff_overflow2.s | 22 ++++++++++++++++
5 files changed, 114 insertions(+), 15 deletions(-)
create mode 100644 ld/testsuite/ld-xtensa/diff_overflow.exp
create mode 100644 ld/testsuite/ld-xtensa/diff_overflow1.s
create mode 100644 ld/testsuite/ld-xtensa/diff_overflow2.s
diff --git a/bfd/elf32-xtensa.c b/bfd/elf32-xtensa.c
index edb04b4..8818d67 100644
--- a/bfd/elf32-xtensa.c
+++ b/bfd/elf32-xtensa.c
@@ -222,11 +222,11 @@ static reloc_howto_type elf_howto_table[] =
FALSE, 0, 0, FALSE),
/* Relocations for supporting difference of symbols. */
- HOWTO (R_XTENSA_DIFF8, 0, 0, 8, FALSE, 0, complain_overflow_bitfield,
+ HOWTO (R_XTENSA_DIFF8, 0, 0, 8, FALSE, 0, complain_overflow_signed,
bfd_elf_xtensa_reloc, "R_XTENSA_DIFF8", FALSE, 0, 0xff, FALSE),
- HOWTO (R_XTENSA_DIFF16, 0, 1, 16, FALSE, 0, complain_overflow_bitfield,
+ HOWTO (R_XTENSA_DIFF16, 0, 1, 16, FALSE, 0, complain_overflow_signed,
bfd_elf_xtensa_reloc, "R_XTENSA_DIFF16", FALSE, 0, 0xffff, FALSE),
- HOWTO (R_XTENSA_DIFF32, 0, 2, 32, FALSE, 0, complain_overflow_bitfield,
+ HOWTO (R_XTENSA_DIFF32, 0, 2, 32, FALSE, 0, complain_overflow_signed,
bfd_elf_xtensa_reloc, "R_XTENSA_DIFF32", FALSE, 0, 0xffffffff, FALSE),
/* General immediate operand relocations. */
@@ -9013,7 +9013,8 @@ relax_section (bfd *abfd, asection *sec, struct bfd_link_info *link_info)
|| r_type == R_XTENSA_DIFF16
|| r_type == R_XTENSA_DIFF32)
{
- bfd_vma diff_value = 0, new_end_offset, diff_mask = 0;
+ bfd_signed_vma diff_value = 0;
+ bfd_vma new_end_offset, diff_mask = 0;
if (bfd_get_section_limit (abfd, sec) < old_source_offset)
{
@@ -9027,15 +9028,15 @@ relax_section (bfd *abfd, asection *sec, struct bfd_link_info *link_info)
{
case R_XTENSA_DIFF8:
diff_value =
- bfd_get_8 (abfd, &contents[old_source_offset]);
+ bfd_get_signed_8 (abfd, &contents[old_source_offset]);
break;
case R_XTENSA_DIFF16:
diff_value =
- bfd_get_16 (abfd, &contents[old_source_offset]);
+ bfd_get_signed_16 (abfd, &contents[old_source_offset]);
break;
case R_XTENSA_DIFF32:
diff_value =
- bfd_get_32 (abfd, &contents[old_source_offset]);
+ bfd_get_signed_32 (abfd, &contents[old_source_offset]);
break;
}
@@ -9047,24 +9048,25 @@ relax_section (bfd *abfd, asection *sec, struct bfd_link_info *link_info)
switch (r_type)
{
case R_XTENSA_DIFF8:
- diff_mask = 0xff;
- bfd_put_8 (abfd, diff_value,
+ diff_mask = 0x7f;
+ bfd_put_signed_8 (abfd, diff_value,
&contents[old_source_offset]);
break;
case R_XTENSA_DIFF16:
- diff_mask = 0xffff;
- bfd_put_16 (abfd, diff_value,
+ diff_mask = 0x7fff;
+ bfd_put_signed_16 (abfd, diff_value,
&contents[old_source_offset]);
break;
case R_XTENSA_DIFF32:
- diff_mask = 0xffffffff;
- bfd_put_32 (abfd, diff_value,
+ diff_mask = 0x7fffffff;
+ bfd_put_signed_32 (abfd, diff_value,
&contents[old_source_offset]);
break;
}
- /* Check for overflow. */
- if ((diff_value & ~diff_mask) != 0)
+ /* Check for overflow. Sign bits must be all zeroes or all ones */
+ if ((diff_value & ~diff_mask) != 0 &&
+ (diff_value & ~diff_mask) != (-1 & ~diff_mask))
{
(*link_info->callbacks->reloc_dangerous)
(link_info, _("overflow after relaxation"),
diff --git a/gas/config/tc-xtensa.c b/gas/config/tc-xtensa.c
index 58ace38..7547c0a0 100644
--- a/gas/config/tc-xtensa.c
+++ b/gas/config/tc-xtensa.c
@@ -5867,12 +5867,15 @@ md_apply_fix (fixS *fixP, valueT *valP, segT seg)
{
case BFD_RELOC_8:
fixP->fx_r_type = BFD_RELOC_XTENSA_DIFF8;
+ fixP->fx_signed = 1;
break;
case BFD_RELOC_16:
fixP->fx_r_type = BFD_RELOC_XTENSA_DIFF16;
+ fixP->fx_signed = 1;
break;
case BFD_RELOC_32:
fixP->fx_r_type = BFD_RELOC_XTENSA_DIFF32;
+ fixP->fx_signed = 1;
break;
default:
break;
diff --git a/ld/testsuite/ld-xtensa/diff_overflow.exp b/ld/testsuite/ld-xtensa/diff_overflow.exp
new file mode 100644
index 0000000..c97578b
--- /dev/null
+++ b/ld/testsuite/ld-xtensa/diff_overflow.exp
@@ -0,0 +1,45 @@
+# Test DIFF* relocation signedness and overflow checking
+# By Max Filippov, Cadence Design Systems, Inc.
+# Copyright (C) 2014 Free Software Foundation, Inc.
+#
+# This file is part of the GNU Binutils.
+#
+# 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.
+
+if ![istarget "xtensa*-*-*"] {
+ return
+}
+
+set testname "DIFF_OVERFLOW"
+
+if ![ld_assemble $as "--text-section-literals $srcdir/$subdir/diff_overflow1.s" tmpdir/diff_overflow1.o] {
+ unresolved $testname
+ return
+}
+if ![ld_assemble $as "--text-section-literals $srcdir/$subdir/diff_overflow2.s" tmpdir/diff_overflow2.o] {
+ unresolved $testname
+ return
+}
+
+set object "tmpdir/diff_overflow"
+
+if ![ld_simple_link $ld $object "tmpdir/diff_overflow1.o tmpdir/diff_overflow2.o"] {
+ verbose -log "failure in ld"
+ fail $testname
+ return
+}
+
+pass $testname
diff --git a/ld/testsuite/ld-xtensa/diff_overflow1.s b/ld/testsuite/ld-xtensa/diff_overflow1.s
new file mode 100644
index 0000000..38519da
--- /dev/null
+++ b/ld/testsuite/ld-xtensa/diff_overflow1.s
@@ -0,0 +1,27 @@
+ .section .text.f0,"axG",@progbits,f0,comdat
+ .literal_position
+ .literal .L0, 0
+ .align 4
+f0:
+ entry a1, 32
+ l32r a2, .L0
+ retw
+
+ .section .text
+ .literal_position
+ .global _start
+_start:
+ entry a1, 32
+ retw
+
+ .section .text.f1,"axG",@progbits,f1,comdat
+ .literal_position
+ .literal .L1, 0
+ .literal .L2, 0
+ .align 4
+ .global f1
+f1:
+ entry a1, 32
+ l32r a2, .L1
+ l32r a3, .L2
+ retw
diff --git a/ld/testsuite/ld-xtensa/diff_overflow2.s b/ld/testsuite/ld-xtensa/diff_overflow2.s
new file mode 100644
index 0000000..096ae39
--- /dev/null
+++ b/ld/testsuite/ld-xtensa/diff_overflow2.s
@@ -0,0 +1,22 @@
+ .section .text.f1,"axG",@progbits,f1,comdat
+ .literal_position
+ .literal .L5, 0
+ .align 4
+f4:
+ entry a1, 32
+.Lf4:
+ l32r a2, .L5
+ l32r a2, .L5
+ nop
+ nop
+ retw
+
+ .section .text
+f5:
+ entry a1, 32
+.Lf5:
+ retw
+
+ .section .debug_frame,"",@progbits
+ .byte .Lf4 - f4
+ .byte .Lf5 - f5
--
1.8.1.4
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