[committed, PATCH] Add -z noreloc-overflow option to x86-64 ld
H.J. Lu
hongjiu.lu@intel.com
Tue Mar 15 18:10:00 GMT 2016
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.
---
bfd/elf64-x86-64.c | 14 ++++++++++----
include/bfdlink.h | 3 +++
ld/Makefile.am | 1 +
ld/Makefile.in | 1 +
ld/NEWS | 3 +++
ld/emulparams/elf32_x86_64.sh | 1 +
ld/emulparams/elf_x86_64.sh | 1 +
ld/emulparams/reloc_overflow.sh | 11 +++++++++++
ld/ld.texinfo | 5 +++++
ld/testsuite/ld-x86-64/pr19807-1.s | 8 ++++++++
ld/testsuite/ld-x86-64/pr19807-1a.d | 13 +++++++++++++
ld/testsuite/ld-x86-64/pr19807-1b.d | 13 +++++++++++++
ld/testsuite/ld-x86-64/pr19807-2.s | 8 ++++++++
ld/testsuite/ld-x86-64/pr19807-2a.d | 4 ++++
ld/testsuite/ld-x86-64/pr19807-2b.d | 8 ++++++++
ld/testsuite/ld-x86-64/pr19807-2c.d | 13 +++++++++++++
ld/testsuite/ld-x86-64/pr19807-2d.d | 8 ++++++++
ld/testsuite/ld-x86-64/pr19807-2e.d | 13 +++++++++++++
ld/testsuite/ld-x86-64/x86-64.exp | 7 +++++++
19 files changed, 131 insertions(+), 4 deletions(-)
create mode 100644 ld/emulparams/reloc_overflow.sh
create mode 100644 ld/testsuite/ld-x86-64/pr19807-1.s
create mode 100644 ld/testsuite/ld-x86-64/pr19807-1a.d
create mode 100644 ld/testsuite/ld-x86-64/pr19807-1b.d
create mode 100644 ld/testsuite/ld-x86-64/pr19807-2.s
create mode 100644 ld/testsuite/ld-x86-64/pr19807-2a.d
create mode 100644 ld/testsuite/ld-x86-64/pr19807-2b.d
create mode 100644 ld/testsuite/ld-x86-64/pr19807-2c.d
create mode 100644 ld/testsuite/ld-x86-64/pr19807-2d.d
create mode 100644 ld/testsuite/ld-x86-64/pr19807-2e.d
diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c
index 380376d..31b1f87 100644
--- a/bfd/elf64-x86-64.c
+++ b/bfd/elf64-x86-64.c
@@ -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);
diff --git a/include/bfdlink.h b/include/bfdlink.h
index eeea6ef..a285f6d 100644
--- a/include/bfdlink.h
+++ b/include/bfdlink.h
@@ -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;
diff --git a/ld/Makefile.am b/ld/Makefile.am
index 4a8c0b6..d14e769 100644
--- a/ld/Makefile.am
+++ b/ld/Makefile.am
@@ -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@
diff --git a/ld/Makefile.in b/ld/Makefile.in
index 45388d7..8c69228 100644
--- a/ld/Makefile.in
+++ b/ld/Makefile.in
@@ -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
diff --git a/ld/NEWS b/ld/NEWS
index 4bf8091..b88da5c 100644
--- a/ld/NEWS
+++ b/ld/NEWS
@@ -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.
diff --git a/ld/emulparams/elf32_x86_64.sh b/ld/emulparams/elf32_x86_64.sh
index 1b285c5..967c1b4 100644
--- a/ld/emulparams/elf32_x86_64.sh
+++ b/ld/emulparams/elf32_x86_64.sh
@@ -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
diff --git a/ld/emulparams/elf_x86_64.sh b/ld/emulparams/elf_x86_64.sh
index 0159a6c..e935f90 100644
--- a/ld/emulparams/elf_x86_64.sh
+++ b/ld/emulparams/elf_x86_64.sh
@@ -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
. ${srcdir}/emulparams/call_nop.sh
SCRIPT_NAME=elf
ELFSIZE=64
diff --git a/ld/emulparams/reloc_overflow.sh b/ld/emulparams/reloc_overflow.sh
new file mode 100644
index 0000000..7ba0ee5
--- /dev/null
+++ b/ld/emulparams/reloc_overflow.sh
@@ -0,0 +1,11 @@
+PARSE_AND_LIST_OPTIONS_RELOC_OVERFLOW='
+ fprintf (file, _("\
+ -z noreloc-overflow Disable relocation overflow check\n"));
+'
+PARSE_AND_LIST_ARGS_CASE_Z_RELOC_OVERFLOW='
+ else if (strcmp (optarg, "noreloc-overflow") == 0)
+ link_info.no_reloc_overflow_check = TRUE;
+'
+
+PARSE_AND_LIST_OPTIONS="$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"
diff --git a/ld/ld.texinfo b/ld/ld.texinfo
index b2b99ab..d3d8dc6 100644
--- a/ld/ld.texinfo
+++ b/ld/ld.texinfo
@@ -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
diff --git a/ld/testsuite/ld-x86-64/pr19807-1.s b/ld/testsuite/ld-x86-64/pr19807-1.s
new file mode 100644
index 0000000..0870f6a
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/pr19807-1.s
@@ -0,0 +1,8 @@
+ .globl _start
+ .type _start, @function
+_start:
+ movq $foo, %rax
+ .size _start, .-_start
+ .data
+foo:
+ .quad 0
diff --git a/ld/testsuite/ld-x86-64/pr19807-1a.d b/ld/testsuite/ld-x86-64/pr19807-1a.d
new file mode 100644
index 0000000..f3c5390
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/pr19807-1a.d
@@ -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
diff --git a/ld/testsuite/ld-x86-64/pr19807-1b.d b/ld/testsuite/ld-x86-64/pr19807-1b.d
new file mode 100644
index 0000000..6af4985
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/pr19807-1b.d
@@ -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
diff --git a/ld/testsuite/ld-x86-64/pr19807-2.s b/ld/testsuite/ld-x86-64/pr19807-2.s
new file mode 100644
index 0000000..2b309f2
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/pr19807-2.s
@@ -0,0 +1,8 @@
+ .globl _start
+ .type _start, @function
+_start:
+ movl $foo, %eax
+ .size _start, .-_start
+ .data
+foo:
+ .quad 0
diff --git a/ld/testsuite/ld-x86-64/pr19807-2a.d b/ld/testsuite/ld-x86-64/pr19807-2a.d
new file mode 100644
index 0000000..1357d72
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/pr19807-2a.d
@@ -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
diff --git a/ld/testsuite/ld-x86-64/pr19807-2b.d b/ld/testsuite/ld-x86-64/pr19807-2b.d
new file mode 100644
index 0000000..a781b30
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/pr19807-2b.d
@@ -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]+
diff --git a/ld/testsuite/ld-x86-64/pr19807-2c.d b/ld/testsuite/ld-x86-64/pr19807-2c.d
new file mode 100644
index 0000000..83ac641
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/pr19807-2c.d
@@ -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
diff --git a/ld/testsuite/ld-x86-64/pr19807-2d.d b/ld/testsuite/ld-x86-64/pr19807-2d.d
new file mode 100644
index 0000000..1171283
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/pr19807-2d.d
@@ -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]+
diff --git a/ld/testsuite/ld-x86-64/pr19807-2e.d b/ld/testsuite/ld-x86-64/pr19807-2e.d
new file mode 100644
index 0000000..f26616a
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/pr19807-2e.d
@@ -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
diff --git a/ld/testsuite/ld-x86-64/x86-64.exp b/ld/testsuite/ld-x86-64/x86-64.exp
index 49f9fa3..8f29761 100644
--- a/ld/testsuite/ld-x86-64/x86-64.exp
+++ b/ld/testsuite/ld-x86-64/x86-64.exp
@@ -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
--
2.5.0
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