Add -z noreloc-overflow option to x86-64 ld

Add -z noreloc-overflow command-line option to the x86-64 ELF linker to
disable relocation overflow check.  This can be used to avoid relocation
overflow check if there will be no dynamic relocation overflow at
run-time.

bfd/

	PR ld/19807
	* elf64-x86-64.c (elf_x86_64_relocate_section): Check
	no_reloc_overflow_check to diable R_X86_64_32/R_X86_64_32S
	relocation overflow check.

include/

	PR ld/19807
	* bfdlink.h (bfd_link_info): Add no_reloc_overflow_check.

ld/

	PR ld/19807
	* Makefile.am (ELF_X86_DEPS): Add
	$(srcdir)/emulparams/reloc_overflow.sh.
	* Makefile.in: Regenerated.
	* NEWS: Mention -z noreloc-overflow.
	* ld.texinfo: Document -z noreloc-overflow.
	* emulparams/elf32_x86_64.sh: Source
	${srcdir}/emulparams/reloc_overflow.sh.
	* emulparams/elf_x86_64.sh: Likewise.
	* emulparams/reloc_overflow.sh: New file.
	* testsuite/ld-x86-64/pr19807-1.s: New file.
	* testsuite/ld-x86-64/pr19807-1a.d: Likewise.
	* testsuite/ld-x86-64/pr19807-1b.d: Likewise.
	* testsuite/ld-x86-64/pr19807-2.s: Likewise.
	* testsuite/ld-x86-64/pr19807-2a.d: Likewise.
	* testsuite/ld-x86-64/pr19807-2b.d: Likewise.
	* testsuite/ld-x86-64/pr19807-2c.d: Likewise.
	* testsuite/ld-x86-64/pr19807-2d.d: Likewise.
	* testsuite/ld-x86-64/pr19807-2e.d: Likewise.
	* testsuite/ld-x86-64/x86-64.exp: Run PR ld/19807 tests.
This commit is contained in:
H.J. Lu 2016-03-15 11:07:06 -07:00
parent 1eb2dbb8d7
commit 4c10bbaa09
22 changed files with 166 additions and 4 deletions

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@ -1,3 +1,10 @@
2016-03-15 H.J. Lu <hongjiu.lu@intel.com>
PR ld/19807
* elf64-x86-64.c (elf_x86_64_relocate_section): Check
no_reloc_overflow_check to diable R_X86_64_32/R_X86_64_32S
relocation overflow check.
2016-03-14 H.J. Lu <hongjiu.lu@intel.com>
* bfd-in2.h: Regenerated.

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@ -1973,8 +1973,10 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info,
/* Let's help debug shared library creation. These relocs
cannot be used in shared libs. Don't error out for
sections we don't care about, such as debug sections or
non-constant sections. */
if (bfd_link_pic (info)
non-constant sections, or when relocation overflow check
is disabled. */
if (!info->no_reloc_overflow_check
&& bfd_link_pic (info)
&& (sec->flags & SEC_ALLOC) != 0
&& (sec->flags & SEC_READONLY) != 0)
{
@ -4842,8 +4844,12 @@ direct:
}
else
{
/* This symbol is local, or marked to become local. */
if (r_type == htab->pointer_r_type)
/* This symbol is local, or marked to become local.
When relocation overflow check is disabled, we
convert R_X86_64_32 to dynamic R_X86_64_RELATIVE. */
if (r_type == htab->pointer_r_type
|| (r_type == R_X86_64_32
&& info->no_reloc_overflow_check))
{
relocate = TRUE;
outrel.r_info = htab->r_info (0, R_X86_64_RELATIVE);

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@ -1,3 +1,8 @@
2016-03-15 H.J. Lu <hongjiu.lu@intel.com>
PR ld/19807
* bfdlink.h (bfd_link_info): Add no_reloc_overflow_check.
2016-03-08 Cupertino Miranda <Cupertino.Miranda@synopsys.com>
Andrew Burgess <andrew.burgess@embecosm.com>

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@ -446,6 +446,9 @@ struct bfd_link_info
/* TRUE if generation of .interp/PT_INTERP should be suppressed. */
unsigned int nointerp: 1;
/* TRUE if we shouldn't check relocation overflow. */
unsigned int no_reloc_overflow_check: 1;
/* TRUE if generate a 1-byte NOP as suffix for x86 call instruction. */
unsigned int call_nop_as_suffix : 1;

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@ -1,3 +1,26 @@
2016-03-15 H.J. Lu <hongjiu.lu@intel.com>
PR ld/19807
* Makefile.am (ELF_X86_DEPS): Add
$(srcdir)/emulparams/reloc_overflow.sh.
* Makefile.in: Regenerated.
* NEWS: Mention -z noreloc-overflow.
* ld.texinfo: Document -z noreloc-overflow.
* emulparams/elf32_x86_64.sh: Source
${srcdir}/emulparams/reloc_overflow.sh.
* emulparams/elf_x86_64.sh: Likewise.
* emulparams/reloc_overflow.sh: New file.
* testsuite/ld-x86-64/pr19807-1.s: New file.
* testsuite/ld-x86-64/pr19807-1a.d: Likewise.
* testsuite/ld-x86-64/pr19807-1b.d: Likewise.
* testsuite/ld-x86-64/pr19807-2.s: Likewise.
* testsuite/ld-x86-64/pr19807-2a.d: Likewise.
* testsuite/ld-x86-64/pr19807-2b.d: Likewise.
* testsuite/ld-x86-64/pr19807-2c.d: Likewise.
* testsuite/ld-x86-64/pr19807-2d.d: Likewise.
* testsuite/ld-x86-64/pr19807-2e.d: Likewise.
* testsuite/ld-x86-64/x86-64.exp: Run PR ld/19807 tests.
2016-03-13 H.J. Lu <hongjiu.lu@intel.com>
PR ld/19539

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@ -672,6 +672,7 @@ ELF_GEN_DEPS = $(srcdir)/emultempl/generic.em $(srcdir)/emultempl/elf-generic.em
ELF_X86_DEPS = $(ELF_DEPS) $(srcdir)/emulparams/plt_unwind.sh \
$(srcdir)/emulparams/extern_protected_data.sh \
$(srcdir)/emulparams/dynamic_undefined_weak.sh \
$(srcdir)/emulparams/reloc_overflow.sh \
$(srcdir)/emulparams/call_nop.sh
@TDIRS@

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@ -888,6 +888,7 @@ ELF_GEN_DEPS = $(srcdir)/emultempl/generic.em $(srcdir)/emultempl/elf-generic.em
ELF_X86_DEPS = $(ELF_DEPS) $(srcdir)/emulparams/plt_unwind.sh \
$(srcdir)/emulparams/extern_protected_data.sh \
$(srcdir)/emulparams/dynamic_undefined_weak.sh \
$(srcdir)/emulparams/reloc_overflow.sh \
$(srcdir)/emulparams/call_nop.sh

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@ -1,5 +1,8 @@
-*- text -*-
* Support for -z noreloc-overflow in the x86-64 ELF linker to disable
relocation overflow check.
* Add -z common/-z nocommon options for ELF targets to control whether to
convert common symbols to the STT_COMMON type during a relocatable link.

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@ -1,6 +1,7 @@
. ${srcdir}/emulparams/plt_unwind.sh
. ${srcdir}/emulparams/extern_protected_data.sh
. ${srcdir}/emulparams/dynamic_undefined_weak.sh
. ${srcdir}/emulparams/reloc_overflow.sh
. ${srcdir}/emulparams/call_nop.sh
SCRIPT_NAME=elf
ELFSIZE=32

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@ -1,6 +1,7 @@
. ${srcdir}/emulparams/plt_unwind.sh
. ${srcdir}/emulparams/extern_protected_data.sh
. ${srcdir}/emulparams/dynamic_undefined_weak.sh
. ${srcdir}/emulparams/reloc_overflow.sh
. ${srcdir}/emulparams/call_nop.sh
SCRIPT_NAME=elf
ELFSIZE=64

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@ -0,0 +1,11 @@
PARSE_AND_LIST_OPTIONS_RELOC_OVERFLOW='
fprintf (file, _("\
-z noreloc-overflow Disable relocation overflow check\n"));
'
PARSE_AND_LIST_ARGS_CASE_Z_RELOC_OVERFLOW='
else if (strcmp (optarg, "noreloc-overflow") == 0)
link_info.no_reloc_overflow_check = TRUE;
'
PARSE_AND_LIST_OPTIONS="$PARSE_AND_LIST_OPTIONS $PARSE_AND_LIST_OPTIONS_RELOC_OVERFLOW"
PARSE_AND_LIST_ARGS_CASE_Z="$PARSE_AND_LIST_ARGS_CASE_Z $PARSE_AND_LIST_ARGS_CASE_Z_RELOC_OVERFLOW"

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@ -1213,6 +1213,11 @@ This option overrides linker backend default. It can be used to avoid
dynamic relocations against undefined weak symbols in executable.
Supported for i386 and x86-64.
@item noreloc-overflow
Disable relocation overflow check. This can be used to disable
relocation overflow check if there will be no dynamic relocation
overflow at run-time. Supported for x86_64.
@item call-nop=prefix-addr
@itemx call-nop=prefix-nop
@itemx call-nop=suffix-nop

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@ -0,0 +1,8 @@
.globl _start
.type _start, @function
_start:
movq $foo, %rax
.size _start, .-_start
.data
foo:
.quad 0

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@ -0,0 +1,13 @@
#source: pr19807-1.s
#as: --64
#ld: -pie -melf_x86_64 -z noreloc-overflow
#objdump: -dw
.*: +file format .*
Disassembly of section .text:
[a-f0-9]+ <_start>:
[ ]*[a-f0-9]+: 48 c7 c0 ([0-9a-f]{2} ){4} mov \$0x[a-f0-9]+,%rax
#pass

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@ -0,0 +1,13 @@
#source: pr19807-1.s
#as: --x32
#ld: -pie -melf32_x86_64 -z noreloc-overflow
#objdump: -dw
.*: +file format .*
Disassembly of section .text:
[a-f0-9]+ <_start>:
[ ]*[a-f0-9]+: 48 c7 c0 ([0-9a-f]{2} ){4} mov \$0x[a-f0-9]+,%rax
#pass

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@ -0,0 +1,8 @@
.globl _start
.type _start, @function
_start:
movl $foo, %eax
.size _start, .-_start
.data
foo:
.quad 0

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@ -0,0 +1,4 @@
#source: pr19807-2.s
#as: --64
#ld: -pie -melf_x86_64
#error: .*relocation R_X86_64_32 against `.data' can not be used when making a shared object; recompile with -fPIC

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@ -0,0 +1,8 @@
#source: pr19807-2.s
#as: --x32
#ld: -pie -melf32_x86_64
#readelf: -r --wide
Relocation section '.rela.dyn' at offset 0x[0-9a-f]+ contains 1 entries:
Offset Info Type Sym. Value Symbol's Name \+ Addend
[0-9a-f]+ +[0-9a-f]+ +R_X86_64_RELATIVE +[0-9a-f]+

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@ -0,0 +1,13 @@
#source: pr19807-2.s
#as: --x32
#ld: -pie -melf32_x86_64
#objdump: -dw
.*: +file format .*
Disassembly of section .text:
[a-f0-9]+ <_start>:
[ ]*[a-f0-9]+: b8 ([0-9a-f]{2} ){4} mov \$0x[a-f0-9]+,%eax
#pass

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@ -0,0 +1,8 @@
#source: pr19807-2.s
#as: --64
#ld: -pie -melf_x86_64 -z noreloc-overflow
#readelf: -r --wide
Relocation section '.rela.dyn' at offset 0x[0-9a-f]+ contains 1 entries:
Offset Info Type Symbol's Value Symbol's Name \+ Addend
[0-9a-f]+ +[0-9a-f]+ +R_X86_64_RELATIVE +[0-9a-f]+

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@ -0,0 +1,13 @@
#source: pr19807-2.s
#as: --64
#ld: -pie -melf_x86_64 -z noreloc-overflow
#objdump: -dw
.*: +file format .*
Disassembly of section .text:
[a-f0-9]+ <_start>:
[ ]*[a-f0-9]+: b8 ([0-9a-f]{2} ){4} mov \$0x[a-f0-9]+,%eax
#pass

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@ -247,6 +247,13 @@ run_dump_test "largecomm-1e"
run_dump_test "largecomm-1f"
run_dump_test "pr19539a"
run_dump_test "pr19539b"
run_dump_test "pr19807-1a"
run_dump_test "pr19807-1b"
run_dump_test "pr19807-2a"
run_dump_test "pr19807-2b"
run_dump_test "pr19807-2c"
run_dump_test "pr19807-2d"
run_dump_test "pr19807-2e"
if { ![istarget "x86_64-*-linux*"] && ![istarget "x86_64-*-nacl*"]} {
return