[PATCH] x86: Restore PC16 relocation overflow check
H.J. Lu
hjl.tools@gmail.com
Thu May 27 17:38:53 GMT 2021
The x86-64 psABI has
---
A program or object file using R_X86_64_8, R_X86_64_16, R_X86_64_PC16
or R_X86_64_PC8 relocations is not conformant to this ABI, these
relocations are only added for documentation purposes.
---
Since x86 PC16 relocations were intended for 16-bit programs in an ELF32
or ELF64 container, PC16 relocation should wrap-around in 16-bit address
space. Revert
commit a7664973b24a242cd9ea17deb5eaf503065fc0bd
Author: Jan Beulich <jbeulich@suse.com>
Date: Mon Apr 26 10:41:35 2021 +0200
x86: correct overflow checking for 16-bit PC-relative relocs
and
commit 50c95a739c91ae70cf8481936611aa1f5397a384
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Wed May 26 12:13:13 2021 -0700
x86: Propery check PC16 reloc overflow in 16-bit mode instructions
while keeping PR ld/27905 tests for PC16 relocation in 16-bit programs.
bfd/
PR ld/27905
* elf32-i386.c: Don't include "libiberty.h".
(elf_howto_table): Revert commits a7664973b24 and 50c95a739c9.
(elf_i386_rtype_to_howto): Revert commit 50c95a739c9.
(elf_i386_info_to_howto_rel): Likewise.
(elf_i386_tls_transition): Likewise.
(elf_i386_relocate_section): Likewise.
* elf64-x86-64.c (x86_64_elf_howto_table): Revert commits
a7664973b24 and 50c95a739c9.
(elf_x86_64_rtype_to_howto): Revert commit 50c95a739c9.
* elfxx-x86.c (_bfd_x86_elf_parse_gnu_properties): Likewise.
* elfxx-x86.h (elf_x86_obj_tdata): Likewise.
(elf_x86_has_code16): Likewise.
binutils/
PR ld/27905
* readelf.c (decode_x86_feature_2): Revert commit 50c95a739c9.
gas/
PR ld/27905
* config/tc-i386.c (set_code_flag): Revert commit 50c95a739c9.
(set_16bit_gcc_code_flag): Likewise.
(x86_cleanup): Likewise.
* testsuite/gas/i386/code16-2.d: Updated.
* testsuite/gas/i386/x86-64-code16-2.d: Likewise.
include/
PR ld/27905
* elf/common.h (GNU_PROPERTY_X86_FEATURE_2_CODE16): Removed.
ld/
PR ld/27905
* testsuite/ld-i386/i386.exp: Don't run pcrel16-2.
* testsuite/ld-x86-64/x86-64.exp: Likewise.
* testsuite/ld-i386/pcrel16-2.d: Removed.
* testsuite/ld-i386/pcrel16-2.s: Likewise.
* testsuite/ld-x86-64/pcrel16-2.d: Likewise.
---
bfd/elf32-i386.c | 25 +++--------
bfd/elf64-x86-64.c | 14 +-----
bfd/elfxx-x86.c | 9 +---
bfd/elfxx-x86.h | 6 ---
binutils/readelf.c | 3 --
gas/config/tc-i386.c | 55 ++++++++----------------
gas/testsuite/gas/i386/code16-2.d | 5 ---
gas/testsuite/gas/i386/x86-64-code16-2.d | 5 ---
include/elf/common.h | 1 -
ld/testsuite/ld-i386/i386.exp | 1 -
ld/testsuite/ld-i386/pcrel16-2.d | 5 ---
ld/testsuite/ld-i386/pcrel16-2.s | 12 ------
ld/testsuite/ld-x86-64/pcrel16-2.d | 5 ---
ld/testsuite/ld-x86-64/x86-64.exp | 1 -
14 files changed, 27 insertions(+), 120 deletions(-)
delete mode 100644 ld/testsuite/ld-i386/pcrel16-2.d
delete mode 100644 ld/testsuite/ld-i386/pcrel16-2.s
delete mode 100644 ld/testsuite/ld-x86-64/pcrel16-2.d
diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c
index c68741af02c..cf7cd076b17 100644
--- a/bfd/elf32-i386.c
+++ b/bfd/elf32-i386.c
@@ -22,7 +22,6 @@
#include "elf-vxworks.h"
#include "dwarf2.h"
#include "opcode/i386.h"
-#include "libiberty.h"
/* 386 uses REL relocations instead of RELA. */
#define USE_REL 1
@@ -94,7 +93,7 @@ static reloc_howto_type elf_howto_table[]=
HOWTO(R_386_16, 0, 1, 16, false, 0, complain_overflow_bitfield,
bfd_elf_generic_reloc, "R_386_16",
true, 0xffff, 0xffff, false),
- HOWTO(R_386_PC16, 0, 1, 16, true, 0, complain_overflow_signed,
+ HOWTO(R_386_PC16, 0, 1, 16, true, 0, complain_overflow_bitfield,
bfd_elf_generic_reloc, "R_386_PC16",
true, 0xffff, 0xffff, true),
HOWTO(R_386_8, 0, 0, 8, false, 0, complain_overflow_bitfield,
@@ -176,14 +175,10 @@ static reloc_howto_type elf_howto_table[]=
false, /* partial_inplace */
0, /* src_mask */
0, /* dst_mask */
- false), /* pcrel_offset */
+ false) /* pcrel_offset */
#define R_386_vt (R_386_GNU_VTENTRY + 1 - R_386_vt_offset)
-/* Use complain_overflow_bitfield on R_386_PC16 for code16. */
- HOWTO(R_386_PC16, 0, 1, 16, true, 0, complain_overflow_bitfield,
- bfd_elf_generic_reloc, "R_386_PC16",
- true, 0xffff, 0xffff, true)
};
#define X86_PCREL_TYPE_P(TYPE) ((TYPE) == R_386_PC32)
@@ -374,7 +369,7 @@ elf_i386_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED,
}
static reloc_howto_type *
-elf_i386_rtype_to_howto (bfd *abfd, unsigned r_type)
+elf_i386_rtype_to_howto (unsigned r_type)
{
unsigned int indx;
@@ -389,11 +384,6 @@ elf_i386_rtype_to_howto (bfd *abfd, unsigned r_type)
/* PR 17512: file: 0f67f69d. */
if (elf_howto_table [indx].type != r_type)
return NULL;
-
- /* Use complain_overflow_bitfield on R_386_PC16 for code16. */
- if (r_type == (unsigned int) R_386_PC16 && elf_x86_has_code16 (abfd))
- indx = ARRAY_SIZE (elf_howto_table) - 1;
-
return &elf_howto_table[indx];
}
@@ -404,8 +394,7 @@ elf_i386_info_to_howto_rel (bfd *abfd,
{
unsigned int r_type = ELF32_R_TYPE (dst->r_info);
- if ((cache_ptr->howto = elf_i386_rtype_to_howto (abfd, r_type))
- == NULL)
+ if ((cache_ptr->howto = elf_i386_rtype_to_howto (r_type)) == NULL)
{
/* xgettext:c-format */
_bfd_error_handler (_("%pB: unsupported relocation type %#x"),
@@ -1153,8 +1142,8 @@ elf_i386_tls_transition (struct bfd_link_info *info, bfd *abfd,
reloc_howto_type *from, *to;
const char *name;
- from = elf_i386_rtype_to_howto (abfd, from_type);
- to = elf_i386_rtype_to_howto (abfd, to_type);
+ from = elf_i386_rtype_to_howto (from_type);
+ to = elf_i386_rtype_to_howto (to_type);
if (h)
name = h->root.root.string;
@@ -2085,7 +2074,7 @@ elf_i386_relocate_section (bfd *output_bfd,
continue;
}
- howto = elf_i386_rtype_to_howto (input_bfd, r_type);
+ howto = elf_i386_rtype_to_howto (r_type);
if (howto == NULL)
return _bfd_unrecognized_reloc (input_bfd, input_section, r_type);
diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c
index d420561c156..98fb88113c0 100644
--- a/bfd/elf64-x86-64.c
+++ b/bfd/elf64-x86-64.c
@@ -82,7 +82,7 @@ static reloc_howto_type x86_64_elf_howto_table[] =
false),
HOWTO(R_X86_64_16, 0, 1, 16, false, 0, complain_overflow_bitfield,
bfd_elf_generic_reloc, "R_X86_64_16", false, 0, 0xffff, false),
- HOWTO(R_X86_64_PC16, 0, 1, 16, true, 0, complain_overflow_signed,
+ HOWTO(R_X86_64_PC16, 0, 1, 16, true, 0, complain_overflow_bitfield,
bfd_elf_generic_reloc, "R_X86_64_PC16", false, 0, 0xffff, true),
HOWTO(R_X86_64_8, 0, 0, 8, false, 0, complain_overflow_bitfield,
bfd_elf_generic_reloc, "R_X86_64_8", false, 0, 0xff, false),
@@ -187,10 +187,6 @@ static reloc_howto_type x86_64_elf_howto_table[] =
_bfd_elf_rel_vtable_reloc_fn, "R_X86_64_GNU_VTENTRY", false, 0, 0,
false),
-/* Use complain_overflow_bitfield on R_X86_64_PC16 for code16. */
- HOWTO(R_X86_64_PC16, 0, 1, 16, true, 0, complain_overflow_bitfield,
- bfd_elf_generic_reloc, "R_X86_64_PC16", false, 0, 0xffff, true),
-
/* Use complain_overflow_bitfield on R_X86_64_32 for x32. */
HOWTO(R_X86_64_32, 0, 2, 32, false, 0, complain_overflow_bitfield,
bfd_elf_generic_reloc, "R_X86_64_32", false, 0, 0xffffffff,
@@ -274,14 +270,6 @@ elf_x86_64_rtype_to_howto (bfd *abfd, unsigned r_type)
else
i = ARRAY_SIZE (x86_64_elf_howto_table) - 1;
}
- else if (r_type == (unsigned int) R_X86_64_PC16)
- {
- /* Use complain_overflow_bitfield on R_X86_64_PC16 for code16. */
- if (elf_x86_has_code16 (abfd))
- i = ARRAY_SIZE (x86_64_elf_howto_table) - 2;
- else
- i = r_type;
- }
else if (r_type < (unsigned int) R_X86_64_GNU_VTINHERIT
|| r_type >= (unsigned int) R_X86_64_max)
{
diff --git a/bfd/elfxx-x86.c b/bfd/elfxx-x86.c
index 29dc7f04b4d..62d516aab8d 100644
--- a/bfd/elfxx-x86.c
+++ b/bfd/elfxx-x86.c
@@ -2353,7 +2353,6 @@ _bfd_x86_elf_parse_gnu_properties (bfd *abfd, unsigned int type,
|| (type >= GNU_PROPERTY_X86_UINT32_OR_AND_LO
&& type <= GNU_PROPERTY_X86_UINT32_OR_AND_HI))
{
- unsigned int number;
if (datasz != 4)
{
_bfd_error_handler
@@ -2362,13 +2361,7 @@ _bfd_x86_elf_parse_gnu_properties (bfd *abfd, unsigned int type,
return property_corrupt;
}
prop = _bfd_elf_get_property (abfd, type, datasz);
- number = bfd_h_get_32 (abfd, ptr);
- if ((abfd->flags
- & (DYNAMIC | BFD_LINKER_CREATED | BFD_PLUGIN)) == 0
- && type == GNU_PROPERTY_X86_FEATURE_2_USED
- && (number & GNU_PROPERTY_X86_FEATURE_2_CODE16) != 0)
- elf_x86_has_code16 (abfd) = 1;
- prop->u.number |= number;
+ prop->u.number |= bfd_h_get_32 (abfd, ptr);
prop->pr_kind = property_number;
return property_number;
}
diff --git a/bfd/elfxx-x86.h b/bfd/elfxx-x86.h
index e8344305492..db11327e96f 100644
--- a/bfd/elfxx-x86.h
+++ b/bfd/elfxx-x86.h
@@ -549,9 +549,6 @@ struct elf_x86_obj_tdata
/* GOTPLT entries for TLS descriptors. */
bfd_vma *local_tlsdesc_gotent;
-
- /* Set if the objec file has 16-bit code. */
- unsigned int has_code16 : 1;
};
enum elf_x86_plt_type
@@ -587,9 +584,6 @@ struct elf_x86_plt
#define elf_x86_local_tlsdesc_gotent(abfd) \
(elf_x86_tdata (abfd)->local_tlsdesc_gotent)
-#define elf_x86_has_code16(abfd) \
- (elf_x86_tdata (abfd)->has_code16)
-
#define elf_x86_compute_jump_table_size(htab) \
((htab)->elf.srelplt->reloc_count * (htab)->got_entry_size)
diff --git a/binutils/readelf.c b/binutils/readelf.c
index a6ed24c03bd..d773b9a4931 100644
--- a/binutils/readelf.c
+++ b/binutils/readelf.c
@@ -19139,9 +19139,6 @@ decode_x86_feature_2 (unsigned int bitmask)
case GNU_PROPERTY_X86_FEATURE_2_XSAVEC:
printf ("XSAVEC");
break;
- case GNU_PROPERTY_X86_FEATURE_2_CODE16:
- printf ("CODE16");
- break;
default:
printf (_("<unknown: %x>"), bit);
break;
diff --git a/gas/config/tc-i386.c b/gas/config/tc-i386.c
index c17f4da16fe..d3441988e34 100644
--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -2695,10 +2695,6 @@ static void
set_code_flag (int value)
{
update_code_flag (value, 0);
-#if defined (OBJ_ELF) || defined (OBJ_MAYBE_ELF)
- if (value == CODE_16BIT)
- x86_feature_2_used |= GNU_PROPERTY_X86_FEATURE_2_CODE16;
-#endif
}
static void
@@ -2710,10 +2706,6 @@ set_16bit_gcc_code_flag (int new_code_flag)
cpu_arch_flags.bitfield.cpu64 = 0;
cpu_arch_flags.bitfield.cpuno64 = 1;
stackop_size = LONG_MNEM_SUFFIX;
-#if defined (OBJ_ELF) || defined (OBJ_MAYBE_ELF)
- if (new_code_flag == CODE_16BIT)
- x86_feature_2_used |= GNU_PROPERTY_X86_FEATURE_2_CODE16;
-#endif
}
static void
@@ -9040,7 +9032,7 @@ x86_cleanup (void)
unsigned int isa_1_descsz_raw, feature_2_descsz_raw;
unsigned int padding;
- if (!IS_ELF || (!x86_used_note && !x86_feature_2_used))
+ if (!IS_ELF || !x86_used_note)
return;
x86_feature_2_used |= GNU_PROPERTY_X86_FEATURE_2_X86;
@@ -9080,23 +9072,15 @@ x86_cleanup (void)
bfd_set_section_alignment (sec, alignment);
elf_section_type (sec) = SHT_NOTE;
- if (x86_used_note)
- {
- /* GNU_PROPERTY_X86_ISA_1_USED: 4-byte type + 4-byte data size
- + 4-byte data */
- isa_1_descsz_raw = 4 + 4 + 4;
- /* Align GNU_PROPERTY_X86_ISA_1_USED. */
- isa_1_descsz = (isa_1_descsz_raw + align_size_1) & ~align_size_1;
- }
- else
- {
- isa_1_descsz_raw = 0;
- isa_1_descsz = 0;
- }
+ /* GNU_PROPERTY_X86_ISA_1_USED: 4-byte type + 4-byte data size
+ + 4-byte data */
+ isa_1_descsz_raw = 4 + 4 + 4;
+ /* Align GNU_PROPERTY_X86_ISA_1_USED. */
+ isa_1_descsz = (isa_1_descsz_raw + align_size_1) & ~align_size_1;
feature_2_descsz_raw = isa_1_descsz;
/* GNU_PROPERTY_X86_FEATURE_2_USED: 4-byte type + 4-byte data size
- + 4-byte data */
+ + 4-byte data */
feature_2_descsz_raw += 4 + 4 + 4;
/* Align GNU_PROPERTY_X86_FEATURE_2_USED. */
feature_2_descsz = ((feature_2_descsz_raw + align_size_1)
@@ -9118,23 +9102,20 @@ x86_cleanup (void)
/* Write n_name. */
memcpy (p + 4 * 3, "GNU", 4);
- if (isa_1_descsz != 0)
- {
- /* Write 4-byte type. */
- md_number_to_chars (p + 4 * 4,
- (valueT) GNU_PROPERTY_X86_ISA_1_USED, 4);
+ /* Write 4-byte type. */
+ md_number_to_chars (p + 4 * 4,
+ (valueT) GNU_PROPERTY_X86_ISA_1_USED, 4);
- /* Write 4-byte data size. */
- md_number_to_chars (p + 4 * 5, (valueT) 4, 4);
+ /* Write 4-byte data size. */
+ md_number_to_chars (p + 4 * 5, (valueT) 4, 4);
- /* Write 4-byte data. */
- md_number_to_chars (p + 4 * 6, (valueT) x86_isa_1_used, 4);
+ /* Write 4-byte data. */
+ md_number_to_chars (p + 4 * 6, (valueT) x86_isa_1_used, 4);
- /* Zero out paddings. */
- padding = isa_1_descsz - isa_1_descsz_raw;
- if (padding)
- memset (p + 4 * 7, 0, padding);
- }
+ /* Zero out paddings. */
+ padding = isa_1_descsz - isa_1_descsz_raw;
+ if (padding)
+ memset (p + 4 * 7, 0, padding);
/* Write 4-byte type. */
md_number_to_chars (p + isa_1_descsz + 4 * 4,
diff --git a/gas/testsuite/gas/i386/code16-2.d b/gas/testsuite/gas/i386/code16-2.d
index 37b66c85f4e..f18c8cd62da 100644
--- a/gas/testsuite/gas/i386/code16-2.d
+++ b/gas/testsuite/gas/i386/code16-2.d
@@ -1,8 +1,3 @@
#name: i386 code16 2
#as: -mx86-used-note=no --generate-missing-build-notes=no
#readelf: -n
-
-Displaying notes found in: .note.gnu.property
-[ ]+Owner[ ]+Data size[ ]+Description
- GNU 0x[0-9a-f]+ NT_GNU_PROPERTY_TYPE_0
- Properties: x86 feature used: x86, CODE16
diff --git a/gas/testsuite/gas/i386/x86-64-code16-2.d b/gas/testsuite/gas/i386/x86-64-code16-2.d
index dbabd67e888..5052353c00d 100644
--- a/gas/testsuite/gas/i386/x86-64-code16-2.d
+++ b/gas/testsuite/gas/i386/x86-64-code16-2.d
@@ -2,8 +2,3 @@
#name: x86-64 code16 2
#as: -mx86-used-note=no --generate-missing-build-notes=no
#readelf: -n
-
-Displaying notes found in: .note.gnu.property
-[ ]+Owner[ ]+Data size[ ]+Description
- GNU 0x[0-9a-f]+ NT_GNU_PROPERTY_TYPE_0
- Properties: x86 feature used: x86, CODE16
diff --git a/include/elf/common.h b/include/elf/common.h
index 564ab711a20..24d0a09b7c8 100644
--- a/include/elf/common.h
+++ b/include/elf/common.h
@@ -872,7 +872,6 @@
#define GNU_PROPERTY_X86_FEATURE_2_XSAVEC (1U << 9)
#define GNU_PROPERTY_X86_FEATURE_2_TMM (1U << 10)
#define GNU_PROPERTY_X86_FEATURE_2_MASK (1U << 11)
-#define GNU_PROPERTY_X86_FEATURE_2_CODE16 (1U << 12)
#define GNU_PROPERTY_X86_COMPAT_2_ISA_1_NEEDED \
(GNU_PROPERTY_X86_UINT32_OR_LO + 0)
diff --git a/ld/testsuite/ld-i386/i386.exp b/ld/testsuite/ld-i386/i386.exp
index 3d6047b790d..4cb5c3a095c 100644
--- a/ld/testsuite/ld-i386/i386.exp
+++ b/ld/testsuite/ld-i386/i386.exp
@@ -297,7 +297,6 @@ run_dump_test "abs"
run_dump_test "pcrel8"
run_dump_test "pcrel16"
run_dump_test "pcrel16abs"
-run_dump_test "pcrel16-2"
run_dump_test "alloc"
run_dump_test "warn1"
run_dump_test "tlsgd2"
diff --git a/ld/testsuite/ld-i386/pcrel16-2.d b/ld/testsuite/ld-i386/pcrel16-2.d
deleted file mode 100644
index c1c340fc75c..00000000000
--- a/ld/testsuite/ld-i386/pcrel16-2.d
+++ /dev/null
@@ -1,5 +0,0 @@
-#name: PCREL16 overflow (2)
-#as: --32
-#ld: -melf_i386
-#error: .*relocation truncated to fit: R_386_PC16 .*t16.*
-#error: .*relocation truncated to fit: R_386_PC16 .*_start.*
diff --git a/ld/testsuite/ld-i386/pcrel16-2.s b/ld/testsuite/ld-i386/pcrel16-2.s
deleted file mode 100644
index 2e974175ae8..00000000000
--- a/ld/testsuite/ld-i386/pcrel16-2.s
+++ /dev/null
@@ -1,12 +0,0 @@
- .text
- .global _start
-_start:
- data16 xbegin t16
- ret
-
- .fill 0x8000,1,0xcc
-
- .global t16
-t16:
- data16 xbegin _start
- ret
diff --git a/ld/testsuite/ld-x86-64/pcrel16-2.d b/ld/testsuite/ld-x86-64/pcrel16-2.d
deleted file mode 100644
index 5346a5b619d..00000000000
--- a/ld/testsuite/ld-x86-64/pcrel16-2.d
+++ /dev/null
@@ -1,5 +0,0 @@
-#name: PCREL16 overflow (2)
-#source: ../ld-i386/pcrel16-2.s
-#ld:
-#error: .*relocation truncated to fit: R_X86_64_PC16 .*t16.*
-#error: .*relocation truncated to fit: R_X86_64_PC16 .*_start.*
diff --git a/ld/testsuite/ld-x86-64/x86-64.exp b/ld/testsuite/ld-x86-64/x86-64.exp
index 80716668df6..5efc215a1a7 100644
--- a/ld/testsuite/ld-x86-64/x86-64.exp
+++ b/ld/testsuite/ld-x86-64/x86-64.exp
@@ -261,7 +261,6 @@ run_dump_test "abs-l1om"
run_dump_test "apic"
run_dump_test "pcrel8"
run_dump_test "pcrel16"
-run_dump_test "pcrel16-2"
run_dump_test "rela"
run_dump_test "tlsgd2"
run_dump_test "tlsgd3"
--
2.31.1
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