1 From 6a17eba5358549d0d6d195bb22b34cdbc068def2 Mon Sep 17 00:00:00 2001
2 From: Volodymyr Arbatov <arbatov@cadence.com>
3 Date: Mon, 6 May 2013 09:43:21 -0800
4 Subject: [PATCH] Use signed data type for R_XTENSA_DIFF* relocation offsets.
6 R_XTENSA_DIFF relocation offsets are in fact signed. Treat them as such.
7 Add testcase that examines ld behaviour on R_XTENSA_DIFF relocation
8 changing sign during relaxation.
10 2014-05-02 Volodymyr Arbatov <arbatov@cadence.com>
11 David Weatherford <weath@cadence.com>
12 Max Filippov <jcmvbkbc@gmail.com>
15 * elf32-xtensa.c (relax_section): treat R_XTENSA_DIFF* relocations as
19 * config/tc-xtensa.c (md_apply_fix): mark BFD_RELOC_XTENSA_DIFF*
22 Backported from: 1058c7532d0b012ac329219264ddad59049fb6e6
23 Changes to Changelog files and tests are dropped.
25 bfd/elf32-xtensa.c | 32 ++++++++++++-----------
26 gas/config/tc-xtensa.c | 3 +++
27 2 files changed, 20 insertions(+), 15 deletions(-)
29 diff --git a/bfd/elf32-xtensa.c b/bfd/elf32-xtensa.c
30 index edb04b4..8818d67 100644
31 --- a/bfd/elf32-xtensa.c
32 +++ b/bfd/elf32-xtensa.c
33 @@ -222,11 +222,11 @@ static reloc_howto_type elf_howto_table[] =
36 /* Relocations for supporting difference of symbols. */
37 - HOWTO (R_XTENSA_DIFF8, 0, 0, 8, FALSE, 0, complain_overflow_bitfield,
38 + HOWTO (R_XTENSA_DIFF8, 0, 0, 8, FALSE, 0, complain_overflow_signed,
39 bfd_elf_xtensa_reloc, "R_XTENSA_DIFF8", FALSE, 0, 0xff, FALSE),
40 - HOWTO (R_XTENSA_DIFF16, 0, 1, 16, FALSE, 0, complain_overflow_bitfield,
41 + HOWTO (R_XTENSA_DIFF16, 0, 1, 16, FALSE, 0, complain_overflow_signed,
42 bfd_elf_xtensa_reloc, "R_XTENSA_DIFF16", FALSE, 0, 0xffff, FALSE),
43 - HOWTO (R_XTENSA_DIFF32, 0, 2, 32, FALSE, 0, complain_overflow_bitfield,
44 + HOWTO (R_XTENSA_DIFF32, 0, 2, 32, FALSE, 0, complain_overflow_signed,
45 bfd_elf_xtensa_reloc, "R_XTENSA_DIFF32", FALSE, 0, 0xffffffff, FALSE),
47 /* General immediate operand relocations. */
48 @@ -9013,7 +9013,8 @@ relax_section (bfd *abfd, asection *sec, struct bfd_link_info *link_info)
49 || r_type == R_XTENSA_DIFF16
50 || r_type == R_XTENSA_DIFF32)
52 - bfd_vma diff_value = 0, new_end_offset, diff_mask = 0;
53 + bfd_signed_vma diff_value = 0;
54 + bfd_vma new_end_offset, diff_mask = 0;
56 if (bfd_get_section_limit (abfd, sec) < old_source_offset)
58 @@ -9027,15 +9028,15 @@ relax_section (bfd *abfd, asection *sec, struct bfd_link_info *link_info)
62 - bfd_get_8 (abfd, &contents[old_source_offset]);
63 + bfd_get_signed_8 (abfd, &contents[old_source_offset]);
67 - bfd_get_16 (abfd, &contents[old_source_offset]);
68 + bfd_get_signed_16 (abfd, &contents[old_source_offset]);
72 - bfd_get_32 (abfd, &contents[old_source_offset]);
73 + bfd_get_signed_32 (abfd, &contents[old_source_offset]);
77 @@ -9047,24 +9048,25 @@ relax_section (bfd *abfd, asection *sec, struct bfd_link_info *link_info)
82 - bfd_put_8 (abfd, diff_value,
84 + bfd_put_signed_8 (abfd, diff_value,
85 &contents[old_source_offset]);
89 - bfd_put_16 (abfd, diff_value,
91 + bfd_put_signed_16 (abfd, diff_value,
92 &contents[old_source_offset]);
95 - diff_mask = 0xffffffff;
96 - bfd_put_32 (abfd, diff_value,
97 + diff_mask = 0x7fffffff;
98 + bfd_put_signed_32 (abfd, diff_value,
99 &contents[old_source_offset]);
103 - /* Check for overflow. */
104 - if ((diff_value & ~diff_mask) != 0)
105 + /* Check for overflow. Sign bits must be all zeroes or all ones */
106 + if ((diff_value & ~diff_mask) != 0 &&
107 + (diff_value & ~diff_mask) != (-1 & ~diff_mask))
109 (*link_info->callbacks->reloc_dangerous)
110 (link_info, _("overflow after relaxation"),
111 diff --git a/gas/config/tc-xtensa.c b/gas/config/tc-xtensa.c
112 index 58ace38..7547c0a0 100644
113 --- a/gas/config/tc-xtensa.c
114 +++ b/gas/config/tc-xtensa.c
115 @@ -5867,12 +5867,15 @@ md_apply_fix (fixS *fixP, valueT *valP, segT seg)
118 fixP->fx_r_type = BFD_RELOC_XTENSA_DIFF8;
119 + fixP->fx_signed = 1;
122 fixP->fx_r_type = BFD_RELOC_XTENSA_DIFF16;
123 + fixP->fx_signed = 1;
126 fixP->fx_r_type = BFD_RELOC_XTENSA_DIFF32;
127 + fixP->fx_signed = 1;