Code in the linker, present before the addition of .gnu.attributes
support, results in shared libraries not being considered by BFD when
merging e_flags and .gnu.attributes from input files to the output.
That doesn't seem correct to me, but I don't know enough about all the
various ABIs to change the behaviour with any confidence. So this
patch merely punts on dynamic objects in merge_private_bfd_data target
functions, with a FIXME for maintainer attention.
I haven't excluded shared libraries from being considered where the
target merge_private_bfd_data (a) already has code dealing with shared
libraries, or (b) where that function just sets the output to the most
constraining arch/mach combination and other fairly trivial merges, or
(c) when the target has no shared library linker support.
In (a) are: arc, arm, aarch64, riscv, sparc.
In (b) are: bpf, cris, csky, m32r, m68k, mn10300, nios2, tilegx,
tilepro, vax, visium, xtensa.
In (c) are: bpf, cr16, h8300, iq2000, m32c, m68hc11, m68hc12, mcore,
mep, msp430, mt, rl78, rx, v850.
PR 25882
* elf32-bfin.c (elf32_bfin_merge_private_bfd_data): Add FIXME.
* elf32-frv.c (frv_elf_merge_private_bfd_data): Likewise.
* elfxx-mips.c (_bfd_mips_elf_merge_private_bfd_data): Likewise.
* elf32-nds32.c (nds32_elf_merge_private_bfd_data): Likewise.
* elf32-score.c (s3_elf32_score_merge_private_bfd_data): Likewise.
* elf32-score7.c (s7_elf32_score_merge_private_bfd_data): Likewise.
* elf32-sh.c (sh_elf_merge_private_data): Likewise.
* elf32-tic6x.c (elf32_tic6x_merge_attributes): Likewise.
* elf64-ia64-vms.c (elf64_ia64_merge_private_bfd_data): Likewise.
* elfnn-ia64.c (elfNN_ia64_merge_private_bfd_data): Likewise.
PR 25803
gas * config/obj-elf.c (obj_elf_type): Reject ifunc symbols on MIPS
targets.
* testsuite/gas/elf/elf.exp: Add MIPS targets to the list to skip
for the type-2 test.
* testsuite/gas/elf/type-noifunc.e: Update to allow for MIPS
targets running this test.
bfd * elfxx-mips.c (_bfd_mips_elf_adjust_dynamic_symbol): Replace an
abort with a more helpful error message.
For those ELF targets that have .sdata or .sbss sections, or similar
sections, arrange to mark the sections with the SEC_SMALL_DATA flag.
This fixes regressions in nm symbol type caused by removing .sdata
and .sbss from coff_section_type with commit 49d9fd42ac.
* elf32-m32r.c (m32r_elf_section_flags): New function.
(elf_backend_section_flags): Define.
* elf32-nds32.c (nds32_elf_section_flags): New function.
(elf_backend_section_flags): Define.
* elf32-ppc.c (ppc_elf_section_from_shdr): Set SEC_SMALL_DATA for
.sbss and .sdata sections.
* elf32-v850.c (v850_elf_section_from_shdr): Set SEC_SMALL_DATA
for SHF_V850_GPREL sections.
* elf64-alpha.c (elf64_alpha_section_from_shdr): Delete outdated
FIXME.
* elf64-hppa.c (elf64_hppa_section_from_shdr): Set SEC_SMALL_DATA
for SHF_PARISC_SHORT sections.
* elf64-ppc.c (ppc64_elf_section_flags): New function.
(elf_backend_section_flags): Define.
* elfxx-mips.c (_bfd_mips_elf_section_from_shdr): Set SEC_SMALL_DATA
for SHF_MIPS_GPREL sections. Delete FIXME.
There were a number of problems with the previous patch. Firstly,
_bfd_dwarf2_stash_syms didn't do anything when the original file had
dynamic symbols, and secondly, info found by the symbol search didn't
make it out of _bfd_elf_find_nearest_line except in the case of DWARF
functions without external linkage.
PR 23652
* dwarf2.c (_bfd_dwarf2_stash_syms): Break out of loop on finding
matching section.
(_bfd_dwarf2_find_nearest_line): Return an int, with value 2 when
returning info from the symbol table. Do the _bfd_elf_find_function
search also when !found. Call _bfd_dwarf2_stash_syms regardless of
symbols.
* elf64-alpha.c (elf64_alpha_find_nearest_line): Accept dwarf2
result of 1 only.
* elfxx-mips.c (_bfd_mips_elf_find_nearest_line): Likewise.
* libbfd-in.h (_bfd_dwarf2_find_nearest_line): Update prototype.
* libbfd.h: Regenerate.
Sometimes DWARF info for a function is incomplete, and the function
can be retrieved by examining symbols. However, when separate debug
files are used it may be that the original file is completely
stripped of symbols. This patch teaches BFD to look at symbols from
the debug file in that case.
The patch also removes arm_elf_find_function, instead implementing
elf_backend_maybe_function_sym. arm_elf_find_function was written
before the generic _bfd_elf_find_function called maybe_function_sym.
aarch64 copied arm, so that file gets the same treatment. There is
some chance this will speed up arm and aarch64 lookup of function/line.
PR 23652
* dwarf2.c (_bfd_dwarf2_stash_syms): New function.
(_bfd_dwarf2_find_nearest_line): Use it here, passing syms to
_bfd_elf_find_function. Call _bfd_elf_find_function in cases
where _bfd_elf_find_nearest_line would do so.
* elf.c (_bfd_elf_find_nearest_line): Omit _bfd_elf_find_function
for dwarf2.
* elfxx-mips.c (_bfd_mips_elf_find_nearest_line): Similarly. Tidy.
* elf32-arm.c (elf32_arm_maybe_function_sym): New function.
(elf_backend_maybe_function_sym): Define.
(arm_elf_find_function, elf32_arm_find_nearest_line): Delete.
(bfd_elf32_find_nearest_line): Don't define.
* elfnn-aarch64.c (elfNN_aarch64_maybe_function_sym): New function.
(elf_backend_maybe_function_sym): Define.
(aarch64_elf_find_function, elfNN_aarch64_find_nearest_line): Delete.
(bfd_elfNN_find_nearest_line): Don't define.
This parameter might appear to be used to set up offset_size, but
since git commit 024b2372f5 offset_size is either set from the
debug_info data or is set to 4.
* dwarf2.c (_bfd_dwarf2_find_nearest_line): Remove addr_size parameter.
* libbfd-in.h (_bfd_dwarf2_find_nearest_line): Update prototype.
* coffgen.c (coff_find_nearest_line_with_names): Adjust
_bfd_dwarf2_find_nearest_line calls.
* elf.c (_bfd_elf_find_nearest_line, _bfd_elf_find_line): Likewise.
* elf32-arm.c (elf32_arm_find_nearest_line): Likewise.
* elf64-alpha.c (elf64_alpha_find_nearest_line): Likewise.
* elfnn-aarch64.c (elfNN_aarch64_find_nearest_line): Likewise.
* elfxx-mips.c (_bfd_mips_elf_find_nearest_line): Likewise.
* mach-o.c (bfd_mach_o_find_nearest_line): Likewise.
* libbfd.h: Regenerate.
This patch is a reimplementation of [1] which was submitted in 2015 by
Neil Schellenberger. Copyright issue was sorted out [2] last year.
It proposed a new section (.gnu.xhash) and related dynamic tag
(DT_GNU_XHASH). The new section would be virtually identical to the
existing .gnu.hash except for the translation table (xlat) which would
contain correct MIPS .dynsym indexes corresponding to the hashvals in
chains. This is because MIPS ABI imposes a different ordering on the
dynsyms than the one expected by the .gnu.hash section. Another addition
would be a leading word (ngnusyms) which would contain the number of
entries in the translation table.
In this patch, the new section name and dynamic tag are changed to
reflect the fact that the section should be treated as MIPS-specific
(.MIPS.xhash and DT_MIPS_XHASH).
This patch addresses the alignment issue as reported in [3], which is
caused by the leading word added to the .MIPS.xhash section. Leading word
is removed in this patch, and the number of entries in the translation
table is now calculated using DT_MIPS_SYMTABNO dynamic tag (this is
addressed by the corresponding glibc patch).
Suggestions on coding style in [4] were taken into account. Existing
GNU hash testcase was covered, and another one was added in the MIPS
part of the testsuite.
The other major change is reserving MIPS ABI version 5 for .MIPS.xhash,
marking the need of support for .MIPS.xhash in the dynamic linker (again,
addressed in the corresponding glibc patch). This is something which I
am not sure of, especially after reading [5]. I am confused on whether
this ABI version is reserved for IFUNC, or it can be used for this
purpose.
Already mentioned glibc patch is submitted at:
https://sourceware.org/ml/libc-alpha/2019-06/msg00456.html
[1] https://sourceware.org/ml/binutils/2015-10/msg00057.html
[2] https://sourceware.org/ml/binutils/2018-03/msg00025.html
[3] https://sourceware.org/ml/binutils/2016-01/msg00006.html
[4] https://sourceware.org/ml/binutils/2016-02/msg00097.html
[5] https://sourceware.org/ml/libc-alpha/2016-12/msg00853.html
ld * emulparams/elf32bmip.sh: Add .MIPS.xhash section.
* emulparams/elf32bmipn32-defs.sh: Add .MIPS.xhash section.
* emulparams/elf64bmip-defs.sh: Add .MIPS.xhash section.
* emultempl/mipself.em: Remove mips_after_parse function.
* testsuite/ld-elf/hash.d: Update comment.
* testsuite/ld-mips-elf/hash1.d: New test.
* testsuite/ld-mips-elf/hash1.s: Ditto.
* testsuite/ld-mips-elf/hash1a.d: Remove.
* testsuite/ld-mips-elf/hash1b.d: Ditto.
* testsuite/ld-mips-elf/hash1c.d: Ditto
* testsuite/ld-mips-elf/hash2.d: New test.
* testsuite/ld-mips-elf/mips-elf.exp: New tests.
* testsuite/ld-mips-elf/start.s: New test.
bfd * elf-bfd.h (struct elf_backend_data): New members.
* elflink.c (_bfd_elf_link_create_dynamic_sections): Create
.gnu.hash section if necessary.
(struct collect_gnu_hash_codes): New member.
(elf_gnu_hash_process_symidx): New function name.
(elf_renumber_gnu_hash_syms): Ignore local and undefined
symbols. Record xlat location for every symbol which should have
a .MIPS.xhash entry.
(bfd_elf_size_dynamic_sections): Add DT_GNU_HASH dynamic tag to
dynamic section if necessary.
(GNU_HASH_SECTION_NAME): New define.
(bfd_elf_size_dynsym_hash_dynstr): Get .MIPS.xhash section.
Update the section size info.
* elfxx-mips.c (struct mips_elf_hash_sort_data): New members.
(struct mips_elf_link_hash_entry): New member.
(mips_elf_link_hash_newfunc): Initialize .MIPS.xhash translation
table location.
(mips_elf_sort_hash_table): Initialize the pointer to the
.MIPS.xhash section.
(mips_elf_sort_hash_table_f): Populate the .MIPS.xhash
translation table entry with the symbol dynindx.
(_bfd_mips_elf_section_from_shdr): Add SHT_MIPS_XHASH.
(_bfd_mips_elf_fake_sections): Initialize .MIPS.xhash section
info.
(_bfd_mips_elf_create_dynamic_sections): Create .MIPS.xhash
section.
(_bfd_mips_elf_size_dynamic_sections): Add DT_MIPS_XHASH tag to
dynamic section.
(_bfd_mips_elf_finish_synamic_sections): Add DT_MIPS_XHASH.
(_bfd_mips_elf_final_write_processing): Set .MIPS.xhash section
sh_link info.
(_bfd_mips_elf_get_target_dtag): Get DT_MIPS_XHASH tag.
(MIPS_LIBC_ABI_XHASH): New ABI version enum value.
(_bfd_mips_post_process_headers): Mark the ABI version as
MIPS_LIBC_ABI_XHASH if there exists a .MIPS.xhash section,
but not a .hash section.
(_bfd_mips_elf_record_xhash_symbol): New function. Record a
position in the translation table, associated with the hash
entry.
* elfxx-mips.h (literal_reloc_p): Define
elf_backend_record_xhash_symbol backend hook.
* elfxx-target.h: Initialize elf_backend_record_xhash_symbol
backend hook.
include * elf/mips.h (SHT_GNU_XHASH): New define.
(DT_GNU_XHASH): New define.
binutils * readelf.c (get_mips_dynamic_type): Return MIPS_XHASH dynamic type.
(get_mips_section_type_name): Return MI{S_XHASH name string.
(dynamic_section_mips_val): Initialize the .MIPS.xhash dynamic
info.
(process_symbol_table): Initialize the .MIPS.xhash section
pointer. Adjust the readelf output to support the new section.
(process_object): Set the .MIPS.xhash dynamic info to zero.
Overflow checks were removed for all hi16 relocations except PC-relative
high relocations per PR ld/16720. Remove overflow checks from %pcrel_hi
relocations so that we can correctly handle negative offsets from PC.
bfd/
* elfxx-mips.c (mips_elf_calculate_relocation) <R_MIPS_PCHI16>:
Remove overflow check.
ld/
* testsuite/ld-mips-elf/undefweak-overflow.s: Remove test case
for pcrel_hi/pcrel_lo.
* testsuite/ld-mips-elf/undefweak-overflow.d: Update to match.
* testsuite/ld-mips-elf/reloc-pcrel-r6.s: New test source.
* testsuite/ld-mips-elf/reloc-pcrel-r6.d: New test linker script.
* testsuite/ld-mips-elf/reloc-pcrel-r6.ld: New test.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new test.
bfd/
* elfxx-mips.c (_bfd_mips_elf_check_relocs): Add NULL pointer
checks. Search the RELA table for n64 relocations.
ld/
* testsuite/ld-mips-elf/pic-reloc-5.d: New test.
* testsuite/ld-mips-elf/pic-reloc-6.d: New test.
* testsuite/ld-mips-elf/pic-reloc-7.d: New test.
* testsuite/ld-mips-elf/pic-reloc-5.s: New test source.
* testsuite/ld-mips-elf/pic-reloc-6.s: New test source.
* testsuite/ld-mips-elf/pic-reloc-7.s: New test source.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.
Add a new option to get the linker to emit PLTs that use compact
branches instead of delay slot branches.
bfd/
* elfxx-mips.c (LA25_BC): New macro.
(mips_elf_link_hash_table)<compact_branches>: New field.
(STUB_JALRC): New macro.
(mipsr6_o32_exec_plt0_entry_compact): New array.
(mipsr6_n32_exec_plt0_entry_compact): Likewise.
(mipsr6_n64_exec_plt0_entry_compact): Likewise.
(mipsr6_exec_plt_entry_compact): Likewise.
(mips_elf_create_la25_stub): Use BC instead of J for stubs
when compact_branches is true.
(_bfd_mips_elf_finish_dynamic_symbol): Choose the compact
PLT for MIPSR6 with compact_branches. Do not reorder the
compact branches PLT. Switch the lazy stub for MIPSR6
with compact_branches to use JALRC.
(mips_finish_exec_plt): Choose the compact PLT0 for MIPSR6
when compact_branches is true.
(_bfd_mips_elf_compact_branches): New function.
* elfxx-mips.h (_bfd_mips_elf_compact_branches): New prototype.
ld/
* emultempl/mipself.em (compact_branches): New static variable.
(mips_create_output_section_statements): Call
_bfd_mips_elf_compact_branches.
(PARSE_AND_LIST_PROLOGUE): Add OPTION_COMPACT_BRANCHES and
OPTION_NO_COMPACT_BRANCHES.
(PARSE_AND_LIST_LONGOPTS): Add compact-branches,
no-compact-branches.
(PARSE_AND_LIST_OPTIONS): Add --compact-branches,
--no-compact-branches.
(PARSE_AND_LIST_ARGS_CASES): Handle the above.
* ld.texinfo: Document --compact-branches, --no-compact-branches.
* testsuite/ld-mips-elf/pic-and-nonpic-1-r6.dd: New test.
* testsuite/ld-mips-elf/pic-and-nonpic-1-r6.nd: New test.
* testsuite/ld-mips-elf/pic-and-nonpic-3a-r6.dd: New test.
* testsuite/ld-mips-elf/pic-and-nonpic-3a-r6.gd: New test.
* testsuite/ld-mips-elf/pic-and-nonpic-1a-r6.s: New test source.
* testsuite/ld-mips-elf/pic-and-nonpic-3a-r6.s: New test source.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.
Accept R_MIPS_HI16, R_MIPS_HIGHER and R_MIPS_HIGHEST relocations and
their compressed counterparts in PIC code where the symbol referred is
absolute. Such an operation is meaningful, because an absolute symbol
effectively is a constant the calculation of the value of which has been
deferred to the static link time, and which is not going to change any
further at the dynamic load time. Therefore there is no need ever to
refuse the use of these relocations with such symbols, as the resulting
run-time value observed by the program will be correct even in PIC code.
This is not the case with R_MIPS_26 and its compressed counterparts,
because the run-time value calculated by the instructions these
relocations are used with depends on the address of the instruction
itself, and that can change according to the base address used by the
dynamic loader. Therefore these relocations have to continue being
rejected in PIC code even with absolute symbols.
This allows successful linking of code that relies on previous linker
behavior up to commit 861fb55ab5 ("Defer allocation of R_MIPS_REL32
GOT slots"), <https://sourceware.org/ml/binutils/2008-08/msg00096.html>,
which introduced the problematic check missing this special exception
for absolute symbols.
bfd/
* elfxx-mips.c (_bfd_mips_elf_check_relocs) <R_MIPS16_HI16>
<R_MIPS_HI16, R_MIPS_HIGHER, R_MIPS_HIGHEST, R_MICROMIPS_HI16>
<R_MICROMIPS_HIGHER, R_MICROMIPS_HIGHEST>: Also accept an
absolute symbol in PIC code.
ld/
* testsuite/ld-mips-elf/pic-reloc-0.d: New test.
* testsuite/ld-mips-elf/pic-reloc-1.d: New test.
* testsuite/ld-mips-elf/pic-reloc-2.d: New test.
* testsuite/ld-mips-elf/pic-reloc-3.d: New test.
* testsuite/ld-mips-elf/pic-reloc-4.d: New test.
* testsuite/ld-mips-elf/pic-reloc-absolute-hi.ld: New test
linker script.
* testsuite/ld-mips-elf/pic-reloc-absolute-lo.ld: New test
linker script.
* testsuite/ld-mips-elf/pic-reloc-ordinary.ld: New test linker
script.
* testsuite/ld-mips-elf/pic-reloc-j.s: New test source.
* testsuite/ld-mips-elf/pic-reloc-lui.s: New test source.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.
Switch from `_bfd_error_handler' to `info->callbacks->einfo' with error
reporting concerning the use of position-dependent relocations such as
R_MIPS_HI16 or R_MIPS_26 in PIC code and continue processing so that any
subsequent link errors are also shown rather than the linker terminating
right away. This can reduce user frustration where correcting one error
only reveals another one; instead all are shown together making them all
possible to investigate at once. The use of the `%X' specifier causes
the linker to terminate unsuccessfully at the end of processing.
Also fix the message to say `cannot' rather than `can not'.
bfd/
* elfxx-mips.c (_bfd_mips_elf_check_relocs) <R_MIPS16_26>
<R_MIPS_26, R_MICROMIPS_26_S1>: Use `info->callbacks->einfo'
rather than `_bfd_error_handler' to report refused relocations
in PIC code and continue processing. Fix error message: `can
not' -> `cannot'.
We have an issue in the MIPS backend, with the handling of undefined
hidden and internal weak symbols. References to such symbols are
supposed to resolve to 0 according to the ELF gABI[1]:
"Unresolved weak symbols have a zero value."
and the 64-bit MIPS psABI[2]:
"If a symbol with one of these [hidden or internal] attributes has no
definition within the executable/DSO being linked, then it must be
resolved to allocated space if common, resolved to zero if weak, or an
error reported otherwise."
however if a GOT relocation is used, then a local GOT entry is created
and used to satisfy the reference. Such an entry is then (in DSO and
PIE binaries) subject to the usual load-time relocation, which means a
non-zero value will be returned if the base address is non-zero. This
will defeat the usual run-time sequence like:
void a (void) __attribute__ ((visibility ("hidden"), weak));
void
x (void)
{
if (a)
a ();
}
This can be reproduced with this simple code:
$ cat libtest.c
extern int a __attribute__ ((visibility ("hidden"), weak));
int *
x (void)
{
return &a;
}
$ cat test.c
int *x (void);
int
main (void)
{
printf ("a: %p\n", x ());
return 0;
}
$ gcc -shared -fPIC -o libtest.so libtest.c
$ gcc -o test test.c -Wl,-rpath,$(pwd) libtest.so
$ ./test
a: 0x77184000
$
The usual approach targets take is making all the steps required to
assign a GOT entry for the symbol referred, and then leave its contents
at zero with no dynamic relocation attached, therefore ensuring that the
value does not change at load time. However this is not going to work
with the implicitly relocated GOT the MIPS psABI specifies[3]:
"The dynamic linker relocates the global offset table by first adding
the difference between the base where the shared object is loaded and
the value of the dynamic tag DT_MIPS_BASE_ADDRESS to all local global
offset table entries."
and we cannot therefore use the local GOT part.
And we cannot offhand use the global part either, as the symbol would
then have to be exported and possibly wrongly preempt symbols in other
modules involved in the dynamic load, because as per the ELF gABI[1] we
are not allowed to enter a hidden or internal symbol into the dynamic
symbol table (and then use its associated GOT entry):
"A hidden symbol contained in a relocatable object must be either
removed or converted to STB_LOCAL binding by the link-editor when the
relocatable object is included in an executable file or shared object."
and:
"An internal symbol contained in a relocatable object must be either
removed or converted to STB_LOCAL binding by the link-editor when the
relocatable object is included in an executable file or shared object."
So we have to choose something else.
Our choice is further limited by the need for the reference associated
with the GOT relocation to stay within the signed 16-bit limit from the
GOT pointer base register, while being compliant with the ELF gABI and
the MIPS psABI. However as Alan Modra has observed[4] one possibility
is to edit (relax) the code such that the GOT reference is removed
altogether.
Based on these observations then modify MIPS BFD linker backend code to:
1. Interpret code associated with GOT relocations and relax the usual LW
or LD instructions into a corresponding immediate load operation that
places the value of 0 in the intended register, while leaving the GOT
entry allocated and initialized as usually.
2. Leave any other instructions associated with GOT relocations in place
and instead redirect the reference to a global GOT entry associated
with a special `__gnu_absolute_zero' symbol created for this purpose,
whose value is 0, SHN_ABS section marks it absolute, binding is
global and export class protected, ensuring that the locally provided
value is always used at load time, and that the value is not
relocated by the dynamic loader.
3. Adjust any high-part GOT relocation used, typically associated with
a LUI instruction, accordingly, so that run-time consistency is
maintained, either by resolving to the original entry if the
instruction associated with the corresponding low-part GOT relocation
has been relaxed to an immediate load (in which case the value loaded
with LUI will be overwritten), or by also redirecting the reference
to `__gnu_absolute_zero' to complete the GOT access sequence if that
symbol has been used.
4. Add a target `elf_backend_hide_symbol' hook, for the three MIPS ABIs,
which prevents the `__gnu_absolute_zero' symbol from being forced
local, to ensure that the redirection works and the symbol remains
global/protected with existing linker scripts unchanged.
5. Observing the issue with handling SHN_ABS symbols in the GNU dynamic
loader, covered by glibc PR 19818, set the EI_ABIVERSION field in the
ELF file header produced to 4 (ABI_ABSOLUTE) if `__gnu_absolute_zero'
symbol has been produced and the target configured indicates the GNU
operating system, so that broken versions of the GNU dynamic loader
gracefully reject the file in loading rather than going astray. Keep
EI_ABIVERSION at the original value for other operating systems or if
no `__gnu_absolute_zero' symbol has been made.
The name of the special `__gnu_absolute_zero' has no meaning other than
how a human reader can interpret it, as it is ignored in dynamic loading
in the handling of the scenarios concerned. This is because the symbol
resolves locally, and it's only the symbol's attributes that matter so
that the associated GOT entry remains unchanged at load time.
Therefore the name is somewhat arbitrary, observing however the need to
use the name space reserved for the system so that it does not conflict
with a possible user symbol, and hence the leading underscore, and also
the `gnu' infix to denote a GNU feature. Other implementations wishing
to address the problem in a similar way may choose a different name and
have the solution still work, possibly with a mixture of modules used in
a dynamic having symbols of different names provided, which will however
not interact with each other due to the protected export class.
The symbol can be referred explicitly, however the name is an internal
implementation detail rather than a part of the ABI, and therefore no
specific semantics is guaranteed.
One limitation of this change is that if `__gnu_absolute_zero' has been
already defined, then we do not wipe the old definition and all kinds of
odd behavior can result. This is however like with other symbols we
internally define, such as `_GLOBAL_OFFSET_TABLE_' or `__rld_map', and
therefore left as a possible future enhancement.
As an optimization the relaxation of LW and LD instructions to a load of
immediate zero is always made, even SVR4 PIC code for code that will end
up in a regular (non-PIE) executable, because there is a cache advantage
with the avoidance of a load from the GOT, even if it is otherwise
guaranteed to remain zero. It does not reliably happen though, due to a
symbol exportation issue affecting executables, covered by PR ld/21805.
One existing test case needs to be updated, as it triggers relaxation
introduced with this change and consequently linker output does not
match expectations anymore. As we want to keep the original issue
covered with the test case modify it then to use the LWL instruction in
place of LW, and adjust the output expected accordingly.
References:
[1] "System V Application Binary Interface - DRAFT - 19 October 2010",
The SCO Group, Section "Symbol Table",
<http://www.sco.com/developers/gabi/2012-12-31/ch4.symtab.html>
[2] "64-bit ELF Object File Specification, Draft Version 2.5", MIPS
Technologies / Silicon Graphics Computer Systems, Order Number
007-4658-001, Section 2.5 "Symbol Table", p. 22,
<http://techpubs.sgi.com/library/manuals/4000/007-4658-001/pdf/007-4658-001.pdf>
[3] "SYSTEM V APPLICATION BINARY INTERFACE, MIPS RISC Processor
Supplement, 3rd Edition", Section "Global Offset Table", p. 5-10,
<http://www.linux-mips.org/pub/linux/mips/doc/ABI/mipsabi.pdf>
[4] "Undo dynamic symbol state after regular object sym type mismatch",
<https://sourceware.org/ml/binutils/2017-07/msg00265.html>
bfd/
PR ld/21375
* elfxx-mips.h (_bfd_mips_elf_hide_symbol): New prototype.
(_bfd_mips_elf_linker_flags): Update prototype.
* elf32-mips.c (elf_backend_hide_symbol): New macro.
* elf64-mips.c (elf_backend_hide_symbol): Likewise.
* elfn32-mips.c (elf_backend_hide_symbol): Likewise.
* elfxx-mips.c (mips_elf_link_hash_table): Add
`use_absolute_zero' and `gnu_target' members.
(mips_elf_record_global_got_symbol): Call
`_bfd_mips_elf_hide_symbol' rather than
`_bfd_elf_link_hash_hide_symbol'.
(mips_use_local_got_p): Return FALSE if the symbol is absolute.
(mips_elf_obtain_contents): Reorder function.
(mips_elf_nullify_got_load): New function.
(mips_elf_calculate_relocation): Add `contents' parameter.
Nullify GOT loads or if it is not possible, then redirect GOT
relocations to the `__gnu_absolute_zero' symbol, for references
that are supposed to resolve to zero.
(mips_elf_define_absolute_zero): New function.
(_bfd_mips_elf_check_relocs): Prepare for arrangements made in
`mips_elf_calculate_relocation' for references made via the GOT
that are supposed to resolve to zero.
(_bfd_mips_elf_hide_symbol): New function.
(_bfd_mips_elf_linker_flags): Add the `gnu_target' parameter,
set the `gnu_target' member of the MIPS hash table.
(MIPS_LIBC_ABI_ABSOLUTE): New enumeration constant.
(_bfd_mips_post_process_headers): Use it.
ld/
PR ld/21375
* emultempl/mipself.em: Set `gnu_target' according to ${target}.
(mips_create_output_section_statements): Update call to
`_bfd_mips_elf_linker_flags'.
* testsuite/ld-mips-elf/pr21334.s: Use LWL rather than LW.
* testsuite/ld-mips-elf/pr21334.dd: Update accordingly.
Move code used to store the contents of a relocated field in output into
a separate function, `mips_elf_store_contents', complementing existing
`mips_elf_obtain_contents'.
bfd/
* elfxx-mips.c (mips_elf_store_contents): New function...
(mips_elf_perform_relocation): ... factored out from here.
The MMI instruction set has been implemented in many Loongson
processors. There is a lot of software optimized for MMI. This patch
splits MMI from loongson2f/3a, and adds GAS and disassembler options for
MMI instructions.
2018-07-20 Chenghua Xu <paul.hua.gm@gmail.com>
Maciej W. Rozycki <macro@mips.com>
bfd/
* elfxx-mips.c (print_mips_ases): Add MMI extension.
binutils/
* readelf.c (print_mips_ases): Add MMI extension.
gas/
* NEWS: Mention MultiMedia extensions Instructions (MMI)
support.
* config/tc-mips.c (options): Add OPTION_LOONGSON_MMI and
OPTION_NO_LOONGSON_MMI.
(md_longopts): Likewise.
(mips_ases): Define availability for MMI.
(mips_convert_ase_flags): Map ASE_LOONGSON_MMI to
AFL_ASE_LOONGSON_MMI.
(mips_cpu_info_table): Add ASE_LOONGSON_MMI for loongson2f/3a.
(md_show_usage): Add help for -mloongson-mmi and
-mno-loongson-mmi.
* doc/as.texi: Document -mloongson-mmi, -mno-loongson-mmi.
* doc/c-mips.texi: Document -mloongson-mmi, -mno-loongson-mmi,
.set loongson-mmi and .set noloongson-mmi.
* testsuite/gas/mips/loongson-2f.d: Move mmi test to ...
* testsuite/gas/mips/loongson-2f-mmi.d: Here. Add ISA/ASE
flag verification.
* testsuite/gas/mips/loongson-2f.s: Move mmi test to ...
* testsuite/gas/mips/loongson-2f-mmi.s: Here.
* testsuite/gas/mips/loongson-3a.d: Move mmi test to ...
* testsuite/gas/mips/loongson-3a-mmi.d: Here. Add ISA/ASE
flag verification.
* testsuite/gas/mips/loongson-3a.s: Move mmi test to ...
* testsuite/gas/mips/loongson-3a-mmi.s: Here.
* testsuite/gas/mips/mips.exp: Run loongson-2f-mmi and
loongson-3a-mmi tests.
include/
* elf/mips.h (AFL_ASE_MMI): New macro.
(AFL_ASE_MASK): Update to include AFL_ASE_LOONGSON_MMI.
* opcode/mips.h (ASE_LOONGSON_MMI): New macro.
opcodes/
* mips-dis.c (mips_arch_choices): Add MMI to loongson2f and
loongson3a descriptors.
(parse_mips_ase_option): Handle -M loongson-mmi option.
(print_mips_disassembler_options): Document -M loongson-mmi.
* mips-opc.c (LMMI): New macro.
(mips_opcodes): Replace IL2F|IL3A marking with LMMI for MMI
instructions.
Fix a crash that occurs in `_bfd_mips_elf_finish_dynamic_sections' if a
dynamic relocation section has been created, but marked to be discarded
by an assignment to the /DISCARD/ output section in a linker script.
In that case the output section is the absolute section, which has no
ELF section data attached, so trying to set its `sh_size' parameter
causes a null pointer dereference.
This is only done as the value for the DT_RELSZ dynamic entry is being
set, so fix the problem by not creating DT_REL, DT_RELSZ or DT_RELENT
dynamic entries in the first place if the dynamic relocation section
will not be output, as with no dynamic relocation data present these
would not serve their purpose anyway.
Add a generic ELF test case to verify that no dynamic relocation data is
reported in the dynamic segment.
bfd/
* elfxx-mips.c (_bfd_mips_elf_size_dynamic_sections): Do not
create DT_REL, DT_RELSZ or DT_RELENT dynamic entries if the
dynamic relocation section will be discarded from output.
(_bfd_mips_elf_finish_dynamic_sections) <DT_RELSZ>: Assert that
the dynamic relocation section will be retained in output.
ld/
* testsuite/ld-elf/reloc-discard.d: New test.
* testsuite/ld-elf/reloc-discard.ld: New test linker script.
* testsuite/ld-elf/reloc-discard.s: New test source.
Correct an issue with commit 0f20cc3522 ("TLS support for MIPS"),
<https://sourceware.org/ml/binutils/2005-02/msg00607.html>, where a
condition used to determine whether to use a dynamic symbol for GD, LD
and IE TLS dynamic relocations against a symbol that has been defined
locally has been incorrectly reversed.
It's executables rather than dynamic shared objects where no symbol is
required, because such symbols cannot be preempted and therefore their
values (thread pointer offsets) are fixed at the static link time as is
the associated module ID of the main executable, so the original
condition should have been `shared' instead of `!shared'. This wrong
condition was then later converted from `!shared' to `!bfd_link_pic',
with commit 0e1862bb40 ("Add output_type to bfd_link_info").
Use the correct `bfd_link_dll' condition then, and adjust code for the
dynamic symbol index possibly being -1 as with symbols that have been
forced local, removing unnecessary dynamic relocations from dynamic
regular executables. PIE executables are unaffected as the existing
condition excluded them by chance due to the conversion mentioned above.
Adjust test cases accordingly.
bfd/
* elfxx-mips.c (mips_tls_got_relocs): Use `bfd_link_dll' rather
than `!bfd_link_pic' in determining the dynamic symbol index.
Avoid the index of -1.
(mips_elf_initialize_tls_slots): Likewise. Flatten code by
moving `dyn' to the beginning of the function block.
ld/
* testsuite/ld-mips-elf/tlsdyn-o32.d: Update test for dynamic
relocation removal.
* testsuite/ld-mips-elf/tlsdyn-o32.got: Likewise.
* testsuite/ld-mips-elf/tlsdyn-o32-1.d: Likewise.
* testsuite/ld-mips-elf/tlsdyn-o32-1.got: Likewise.
* testsuite/ld-mips-elf/tlsdyn-o32-2.d: Likewise.
* testsuite/ld-mips-elf/tlsdyn-o32-2.got: Likewise.
* testsuite/ld-mips-elf/tlsdyn-o32-3.d: Likewise.
* testsuite/ld-mips-elf/tlsdyn-o32-3.got: Likewise.
Correct a commit 0e1862bb40 ("Add output_type to bfd_link_info") issue
and use `bfd_link_dll' rather than `bfd_link_pic' in determining whether
to fully resolve GD, LD and IE TLS relocations referring to symbols
locally defined rather than deferring them to the load time by means of
dynamic relocations.
Such symbols cannot be preempted in PIE executables, which are
necessarily PIC, and therefore their values (thread pointer offsets) are
fixed at the static link time as is the associated module ID of the main
executable.
Given the `tlsbin-o32.s' and `tlsdyn-o32.s' sources from our test suite
this removes the absolute TLS relocations from the static:
DYNAMIC RELOCATION RECORDS
OFFSET TYPE VALUE
00000000 R_MIPS_NONE *ABS*
1000002c R_MIPS_TLS_TPREL32 *ABS*
10000030 R_MIPS_TLS_DTPMOD32 *ABS*
10000038 R_MIPS_TLS_DTPMOD32 *ABS*
and the dynamic:
DYNAMIC RELOCATION RECORDS
OFFSET TYPE VALUE
00000000 R_MIPS_NONE *ABS*
1000002c R_MIPS_TLS_TPREL32 *ABS*
10000038 R_MIPS_TLS_DTPMOD32 *ABS*
10000044 R_MIPS_TLS_DTPMOD32 *ABS*
10000030 R_MIPS_TLS_DTPMOD32 tlsvar_gd
10000034 R_MIPS_TLS_DTPREL32 tlsvar_gd
10000040 R_MIPS_TLS_TPREL32 tlsvar_ie
PIE executable respectively, as reported by `objdump -R', and fills the
corresponding GOT slots with the values expected, as recorded with the
test cases added. The new output from `objdump -R' is:
DYNAMIC RELOCATION RECORDS (none)
and:
DYNAMIC RELOCATION RECORDS
OFFSET TYPE VALUE
00000000 R_MIPS_NONE *ABS*
10000030 R_MIPS_TLS_DTPMOD32 tlsvar_gd
10000034 R_MIPS_TLS_DTPREL32 tlsvar_gd
10000040 R_MIPS_TLS_TPREL32 tlsvar_ie
for the static and the dynamic executable respectively.
2018-07-11 Maciej W. Rozycki <macro@mips.com>
Rich Felker <bugdal@aerifal.cx>
bfd/
PR ld/22570
* elfxx-mips.c (mips_tls_got_relocs): Use `bfd_link_dll' rather
than `bfd_link_pic' to determine whether dynamic relocations are
to be produced.
(mips_elf_initialize_tls_slots): Likewise.
ld/
PR ld/22570
* testsuite/ld-mips-elf/tlsbin-pie-o32.d: New test.
* testsuite/ld-mips-elf/tlsbin-pie-o32.got: New test.
* testsuite/ld-mips-elf/tlsdyn-pie-o32.d: New test.
* testsuite/ld-mips-elf/tlsdyn-pie-o32.got: New test.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.
Correct a MIPS/BFD linker issue with dynamic symbol and corresponding
GOT entry values being redirected to lazy binding stubs where the stubs
section has been discarded by assigning to the `/DISCARD/' output
section in the linker script used. The issue manifests itself by the
values entered being relative to the absolute section, which is what any
discarded sections are internally assigned in the linker.
For the `stub-dynsym-2.s' piece of code included as a test case with
this change this issue results in the dynamic symbol table and the GOT
looking like:
Symbol table '.dynsym' contains 3 entries:
Num: Value Size Type Bind Vis Ndx Name
0: 00000000 0 NOTYPE LOCAL DEFAULT UND
1: 00000010 0 FUNC GLOBAL DEFAULT UND bar
2: 00000000 0 FUNC GLOBAL DEFAULT UND foo
Primary GOT:
Canonical gp value: 00097ff0
Reserved entries:
Address Access Initial Purpose
00090000 -32752(gp) 00000000 Lazy resolver
00090004 -32748(gp) 80000000 Module pointer (GNU extension)
Global entries:
Address Access Initial Sym.Val. Type Ndx Name
00090008 -32744(gp) 00000010 00000010 FUNC UND bar
0009000c -32740(gp) 00000000 00000000 FUNC UND foo
if assembled to regular MIPS code, or:
Symbol table '.dynsym' contains 3 entries:
Num: Value Size Type Bind Vis Ndx Name
0: 00000000 0 NOTYPE LOCAL DEFAULT UND
1: 0000000d 0 FUNC GLOBAL DEFAULT UND bar
2: 00000001 0 FUNC GLOBAL DEFAULT UND foo
Primary GOT:
Canonical gp value: 00097ff0
Reserved entries:
Address Access Initial Purpose
00090000 -32752(gp) 00000000 Lazy resolver
00090004 -32748(gp) 80000000 Module pointer (GNU extension)
Global entries:
Address Access Initial Sym.Val. Type Ndx Name
00090008 -32744(gp) 0000000d 0000000d FUNC UND bar
0009000c -32740(gp) 00000001 00000001 FUNC UND foo
if assembled to microMIPS code. Symbol values and GOT entries record
the offset into the inexistent stubs section and the ISA bit rather than
zero, which would be the case if a lazy binding stub was not used for
other reasons, such as the value of the symbol being taken for a purpose
other than making a function call (e.g. an R_MIPS_GOT16 relocation).
Correct the issue by refraining from redirecting symbols to lazy binding
stubs if the stubs section is going to be discarded.
bfd/
* elfxx-mips.c (_bfd_mips_elf_adjust_dynamic_symbol): Don't set
`->needs_lazy_stub' if the stubs output section is the absolute
section.
ld/
* testsuite/ld-mips-elf/stub-dynsym-2.dd: New test.
* testsuite/ld-mips-elf/stub-dynsym-2.gd: New test.
* testsuite/ld-mips-elf/stub-dynsym-2.sd: New test.
* testsuite/ld-mips-elf/stub-dynsym-discard-2.gd: New test.
* testsuite/ld-mips-elf/stub-dynsym-discard-2.sd: New test.
* testsuite/ld-mips-elf/stub-dynsym-micromips-2.dd: New test.
* testsuite/ld-mips-elf/stub-dynsym-micromips-2.gd: New test.
* testsuite/ld-mips-elf/stub-dynsym-micromips-2.sd: New test.
* testsuite/ld-mips-elf/stub-dynsym-micromips-insn32-2.dd: New
test.
* testsuite/ld-mips-elf/stub-dynsym-micromips-insn32-2.gd: New
test.
* testsuite/ld-mips-elf/stub-dynsym-micromips-insn32-2.sd: New
test.
* testsuite/ld-mips-elf/stub-dynsym-2.ld: New test linker
script.
* testsuite/ld-mips-elf/stub-dynsym-discard-2.ld: New test
linker script.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.
Prevent runtime procedure table symbols, produced with `ict_irix5' MIPS
targets, from being swept in section GC, fixing linker errors like:
./ld-new: tmpdir/dump: protected symbol `_procedure_table_size' isn't defined
./ld-new: final link failed: bad value
triggered whenever section GC is enabled with those targets and
consequently removing the following test suite failures:
FAIL: Build pr22649-2a.so
FAIL: Build pr22649-2c.so
FAIL: PR ld/20828 dynamic symbols with section GC (auxiliary shared library)
FAIL: PR ld/20828 dynamic symbols with section GC (plain)
FAIL: PR ld/20828 dynamic symbols with section GC (version script)
FAIL: PR ld/20828 dynamic symbols with section GC (versioned shared library)
FAIL: PR ld/20828 dynamic symbols with section GC (versioned)
FAIL: --gc-sections with .text._init
FAIL: pr20022
observed with `mips-elf', `tx39-elf', `mipsisa32-elf', `mipsisa64-elf',
`mipsel-elf', `mipsisa32el-elf', `mipsisa64el-elf', `mips64vr-elf',
`mips64vrel-elf', `mips64vr4300-elf', `mips64vr4300el-elf',
`mips-sgi-irix5' and `mips-rtems' targets, among others. This fix makes
section GC usable with the affected targets.
bfd/
* elfxx-mips.c (_bfd_mips_elf_create_dynamic_sections): Set
`mark' for symbols created from `mips_elf_dynsym_rtproc_names'
list.
Remove an extraneous symbol visibility check made for undefined weak
symbols in determination whether an R_MIPS_REL32 dynamic relocation has
to be placed in output, complementing commit ad95120309 ("mips: Check
UNDEFWEAK_NO_DYNAMIC_RELOC"). That check duplicates one already made by
the UNDEFWEAK_NO_DYNAMIC_RELOC macro as a part of a broader condition
used to decide if to enter undefined weak symbols to the dynamic symbol
table or not.
bfd/
* elfxx-mips.c (allocate_dynrelocs): Remove extraneous symbol
visibility check made for undefined weak symbols.
Correct the formatting of `_bfd_mips_elf_compact_eh_encoding' and
`_bfd_mips_elf_cant_unwind_opcode' definitions which extend beyond 79
columns.
bfd/
* elfxx-mips.c (_bfd_mips_elf_compact_eh_encoding)
(_bfd_mips_elf_cant_unwind_opcode): Correct formatting.
Shuffle code in `_bfd_mips_post_process_headers' so that the setting of
the EI_ABIVERSION ELF file header field is complete before calling
`_bfd_elf_post_process_headers'. This used to be the case, but was
changed with commit 351cdf24d2 ("[MIPS] Implement O32 FPXX, FP64 and
FP64A ABI extensions") for no reason.
bfd/
* elfxx-mips.c (_bfd_mips_post_process_headers): Keep
EI_ABIVERSION setting together.
Define enumeration constants based on generated `libc-abis.h' from GNU
libc, adding a MIPS_ prefix as these are port-specific. Use them to
replace magic numbers stored in the EI_ABIVERSION field of the ELF file
header.
bfd/
* elfxx-mips.c (MIPS_LIBC_ABI_DEFAULT, MIPS_LIBC_ABI_MIPS_PLT)
(MIPS_LIBC_ABI_UNIQUE, MIPS_LIBC_ABI_MIPS_O32_FP64)
(MIPS_LIBC_ABI_MAX): New enumeration constants.
(_bfd_mips_post_process_headers): Use them in place of magic
numbers.
The addressable signed 32-bit range for n64 MIPS `.got.plt' references
is from 0xffffffff7fff8000 to 0x7fff7fff, due to how the composition of
an LUI and an LD instruction works for address calculation in the 64-bit
addressing mode, such as when CP0.Status.UX=1.
We currently have a range check in `mips_finish_exec_plt', however it is
not correct as it verifies that the `.got.plt' start address referred is
between 0xffffffff80000000 and 0x7fffffff. It is also implemented as an
assertion rather than a proper error message despite that the situation
can be triggered by user input. Additionally there is no check made for
individual `.got.plt' entries referred even though they can be out of
range while the `.got.plt' start address is not.
Fix all these problems and use the correct range for the check, limiting
it to n64 output files, and then issue a proper error message both in
`mips_finish_exec_plt' and in `_bfd_mips_elf_finish_dynamic_symbol',
suggesting the use of the `-Ttext-segment=...' option that will often
work and with the default linker scripts in particular. Add suitable
tests covering boundary cases.
bfd/
PR ld/22966
* elfxx-mips.c (_bfd_mips_elf_finish_dynamic_symbol): Verify the
`.got.plt' entry referred is in range.
(mips_finish_exec_plt): Correct the range check for `.got.plt'
start. Replace the assertion used for that with a proper error
message.
ld/
PR ld/22966
* testsuite/ld-mips-elf/n64-plt-1.dd: New test.
* testsuite/ld-mips-elf/n64-plt-1.gd: New test.
* testsuite/ld-mips-elf/n64-plt-2.ed: New test.
* testsuite/ld-mips-elf/n64-plt-3.ed: New test.
* testsuite/ld-mips-elf/n64-plt-4.dd: New test.
* testsuite/ld-mips-elf/n64-plt-4.gd: New test.
* testsuite/ld-mips-elf/n64-plt-1.ld: New test linker script.
* testsuite/ld-mips-elf/n64-plt-2.ld: New test linker script.
* testsuite/ld-mips-elf/n64-plt-3.ld: New test linker script.
* testsuite/ld-mips-elf/n64-plt-4.ld: New test linker script.
* testsuite/ld-mips-elf/n64-plt.s: New test source.
* testsuite/ld-mips-elf/n64-plt-lib.s: New test source.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.
Add support for the Global INValidate Application Specific Extension
for Release 6 of the MIPS Architecture.
[1] "MIPS Architecture for Programmers Volume II-A: The MIPS32
Instruction Set Manual", Imagination Technologies Ltd., Document
Number: MD00086, Revision 6.06, December 15, 2016, Section 3.2
"Alphabetical List of Instructions", pp. 187-191
bfd/
* elfxx-mips.c (print_mips_ases): Add GINV extension.
binutils/
* readelf.c (print_mips_ases): Add GINV extension.
gas/
* NEWS: Mention MIPS Global INValidate ASE support.
* config/tc-mips.c (options): Add OPTION_GINV and OPTION_NO_GINV.
(md_longopts): Likewise.
(mips_ases): Define availability for GINV.
(mips_convert_ase_flags): Map ASE_GINV to AFL_ASE_GINV.
(md_show_usage): Add help for -mginv and -mno-ginv.
* doc/as.texinfo: Document -mginv, -mno-ginv.
* doc/c-mips.texi: Document -mginv, -mno-ginv, .set ginv and
.set noginv.
* testsuite/gas/mips/ase-errors-1.s: Add error checks for GINV
ASE.
* testsuite/gas/mips/ase-errors-2.s: Likewise.
* testsuite/gas/mips/ase-errors-1.l: Likewise.
* testsuite/gas/mips/ase-errors-2.l: Likewise.
* testsuite/gas/mips/ginv.d: New test.
* testsuite/gas/mips/ginv-err.d: New test.
* testsuite/gas/mips/ginv-err.l: New test stderr output.
* testsuite/gas/mips/ginv.s: New test source.
* testsuite/gas/mips/ginv-err.s: New test source.
* testsuite/gas/mips/mips.exp: Run the new tests.
include/
* elf/mips.h (AFL_ASE_GINV, AFL_ASE_RESERVED1): New macros.
(AFL_ASE_MASK): Update to include AFL_ASE_GINV.
* opcode/mips.h: Document "+\" operand format.
(ASE_GINV): New macro.
opcodes/
* mips-dis.c (mips_arch_choices): Add GINV to mips32r6 and
mips64r6 descriptors.
(parse_mips_ase_option): Handle -Mginv option.
(print_mips_disassembler_options): Document -Mginv.
* mips-opc.c (decode_mips_operand) <+\>: New operand format.
(GINV): New macro.
(mips_opcodes): Define ginvi and ginvt.