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.
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.
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.
Fix a commit 861fb55ab5 ("Defer allocation of R_MIPS_REL32 GOT
slots"), <https://sourceware.org/ml/binutils/2008-08/msg00096.html>,
regression and a more recent:
FAIL: ld-unique/pr21529
new LD test case failure, observed with all the relevant MIPS targets
whenever the linker is invoked with one or more ELF inputs and the
output format set to `binary'.
The culprit is a segmentation fault caused in `mips_before_allocation'
by a null pointer dereference, where an attempt is made to access the
ELF file header's `e_flags' member, for the purpose of determining
whether to produce a PLT and copy relocations, without first checking
that the output BFD is ELF. The `e_flags' member is stored in BFD's
private data pointed to by `tdep', which in the case of the `binary' BFD
is null, causing the segmentation fault. With other non-ELF BFDs such
as SREC `tdep' is not null and consequently no crash may happen and in
that case random data will be interpreted as it was `e_flags'.
Disable the access to `e_flags' then and all the associated checks and
consequently never produce a PLT and copy relocations if output is not a
MIPS ELF BFD, matching `_bfd_mips_elf_merge_private_bfd_data' that does
not process `e_flags' in that case either and therefore does not let us
decide here anyway if all the input objects included in the link are
suitable for use with a PLT and copy relocations.
ld/
* emultempl/mipself.em (mips_before_allocation): Avoid ELF
processing if not MIPS ELF.
* testsuite/ld-mips-elf/binary.d: New test.
* testsuite/ld-mips-elf/binary.ld: New test linker script.
* testsuite/ld-mips-elf/binary.s: New test source.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new test.
Complement commit 9d862524f6 ("MIPS: Verify the ISA mode and alignment
of branch and jump targets") and add GAS and LD options to control the
checks for invalid branches between ISA modes introduced there, to help
with some handwritten code lacking `.insn' annotation for labels used as
branch targets and code produced by older versions of GCC which suffers
from the issue with branches to code that has been optimized away,
addressed with GCC commit 242424 ("MIPS/GCC: Mark trailing labels with
`.insn'"), <https://gcc.gnu.org/ml/gcc-patches/2016-11/msg01061.html>.
bfd/
* elfxx-mips.h (_bfd_mips_elf_insn32): Rename prototype to...
(_bfd_mips_elf_linker_flags): ... this. Add another parameter.
* elfxx-mips.c (mips_elf_link_hash_table): Add
`ignore_branch_isa' member.
(mips_elf_perform_relocation): Do not treat an ISA mode mismatch
in branch relocation calculation as an error if
`ignore_branch_isa' has been set.
(_bfd_mips_elf_insn32): Rename to...
(_bfd_mips_elf_linker_flags): ... this. Rename the `on'
parameter to `insn32' and add an `ignore_branch_isa' parameter.
Handle the new parameter.
gas/
* config/tc-mips.c (mips_ignore_branch_isa): New variable.
(options): Add OPTION_IGNORE_BRANCH_ISA and
OPTION_NO_IGNORE_BRANCH_ISA enum values.
(md_longopts): Add "mignore-branch-isa" and
"mno-ignore-branch-isa" options.
(md_parse_option): Handle OPTION_IGNORE_BRANCH_ISA and
OPTION_NO_IGNORE_BRANCH_ISA.
(fix_bad_cross_mode_branch_p): Return FALSE if
`mips_ignore_branch_isa' has been set.
(md_show_usage): Add `-mignore-branch-isa' and
`-mno-ignore-branch-isa'.
* doc/as.texinfo (Target MIPS options): Add
`-mignore-branch-isa' and `-mno-ignore-branch-isa' options.
(-mignore-branch-isa, -mno-ignore-branch-isa): New options.
* doc/c-mips.texi (MIPS Options): Add `-mignore-branch-isa' and
`-mno-ignore-branch-isa' options.
* testsuite/gas/mips/branch-local-ignore-2.d: New test.
* testsuite/gas/mips/branch-local-ignore-3.d: New test.
* testsuite/gas/mips/branch-local-ignore-n32-2.d: New test.
* testsuite/gas/mips/branch-local-ignore-n32-3.d: New test.
* testsuite/gas/mips/branch-local-ignore-n64-2.d: New test.
* testsuite/gas/mips/branch-local-ignore-n64-3.d: New test.
* testsuite/gas/mips/mips.exp: Run the new tests.
ld/
* emultempl/mipself.em (ignore_branch_isa): New variable.
(mips_create_output_section_statements): Rename
`_bfd_mips_elf_insn32' called to `_bfd_mips_elf_linker_flags',
add `ignore_branch_isa' argument.
(PARSE_AND_LIST_PROLOGUE): Add OPTION_IGNORE_BRANCH_ISA and
OPTION_NO_IGNORE_BRANCH_ISA enum values.
(PARSE_AND_LIST_LONGOPTS): Add "ignore-branch-isa" and
"no-ignore-branch-isa" options.
(PARSE_AND_LIST_OPTIONS): Add `--ignore-branch-isa' and
`--no-ignore-branch-isa'.
(PARSE_AND_LIST_ARGS_CASES): Handle OPTION_IGNORE_BRANCH_ISA and
OPTION_NO_IGNORE_BRANCH_ISA.
* ld.texinfo (Options specific to MIPS targets): Add
`--ignore-branch-isa' and `--no-ignore-branch-isa' options.
(ld and the MIPS family): Likewise.
* testsuite/ld-mips-elf/bal-jalx-pic-ignore.d: New test.
* testsuite/ld-mips-elf/bal-jalx-pic-ignore-n32.d: New test.
* testsuite/ld-mips-elf/bal-jalx-pic-ignore-n64.d: New test.
* testsuite/ld-mips-elf/unaligned-branch-ignore-2.d: New test.
* testsuite/ld-mips-elf/unaligned-branch-ignore-r6-1: New test.
* testsuite/ld-mips-elf/unaligned-branch-ignore-mips16: New
test.
* testsuite/ld-mips-elf/unaligned-branch-ignore-micromips: New
test.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.
Tie output section statements to their associated output section via
output section userdata. This allows us to avoid hash lookups which
are slower and fail when multiple output sections have the same name.
* ldlang.h (lang_output_section_get): Define.
* ldlang.c (lang_output_section_get): Likewise.
(init_os): Set the output_section userdata to the output
section statement.
* emultempl/hppaelf.em: Use lang_output_section_get instead of
lang_output_section_find where applicable.
* emultempl/aarch64elf.em: Likewise.
* emultempl/aix.em: Likewise.
* emultempl/armelf.em: Likewise.
* emultempl/m68hc1xelf.em: Likewise.
* emultempl/metagelf.em: Likewise.
* emultempl/mipself.em: Likewise.
* emultempl/ppc64elf.em: Likewise.
* emultempl/spuelf.em: Likewise.
* elf.c (_bfd_elf_init_private_section_data): Add an assertion
that the output section has an allocated bfd_elf_section_data
structure.
* elfxx-mips.c (mips_elf_check_symbols): Do not create a stub for
symbols in sections that have been removed by garbage collection.
* emultempl/mipself.em (mips_add_stub_section): Do not add stubs
for sections that have been removed by garbage collection.
Daniel Jacobowitz <dan@codesourcery.com>
Catherine Moore <clm@codesourcery.com>
Mark Shinwell <shinwell@codesourcery.com>
Maxim Kuvyrkov <maxim@codesourcery.com>
* elf32-mips.c (mips_vxworks_copy_howto_rela): Replace with...
(elf_mips_copy_howto): ...this howto. Clear the size fields.
(mips_vxworks_jump_slot_howto_rela): Replace with...
(elf_mips_jump_slot_howto): ...this howto.
(bfd_elf32_bfd_reloc_type_lookup): Handle BFD_RELOC_MIPS_COPY
and BFD_RELOC_MIPS_JUMP_SLOT.
(bfd_elf32_bfd_reloc_name_lookup): Handle "R_MIPS_COPY" and
"R_MIPS_JUMP_SLOT".
(mips_elf32_rtype_to_howto): Handle R_MIPS_COPY and R_MIPS_JUMP_SLOT.
(elf_backend_plt_readonly): Define.
(elf_backend_plt_sym_val): Define for non-VxWorks targets.
(mips_vxworks_bfd_reloc_type_lookup): Delete.
(mips_vxworks_bfd_reloc_name_lookup): Likewise.
(mips_vxworks_rtype_to_howto): Likewise.
(elf_backend_want_dynbss): Don't define for VxWorks.
(elf_backend_plt_readonly): Likewise.
(bfd_elf32_bfd_reloc_type_lookup): Likewise.
(bfd_elf32_bfd_reloc_name_lookup): Likewise.
(elf_backend_mips_rtype_to_howto): Likewise.
(elf_backend_adjust_dynamic_symbol): Likewise.
(elf_backend_got_symbol_offset): Don't define.
* elfn32-mips.c (elf_mips_copy_howto, elf_mips_jump_slot_howto): New.
(bfd_elf32_bfd_reloc_type_lookup): Handle BFD_RELOC_MIPS_COPY
and BFD_RELOC_MIPS_JUMP_SLOT.
(bfd_elf32_bfd_reloc_name_lookup): Handle "R_MIPS_COPY" and
"R_MIPS_JUMP_SLOT".
(mips_elf32_n32_rtype_to_howto): Handle R_MIPS_COPY and
R_MIPS_JUMP_SLOT.
(elf_backend_rela_plts_and_copies_p, elf_backend_plt_readonly)
(elf_backend_plt_sym_val): Define.
* elf64-mips.c (elf_mips_copy_howto, elf_mips_jump_slot_howto): New.
(bfd_elf64_bfd_reloc_type_lookup): Handle BFD_RELOC_MIPS_COPY
and BFD_RELOC_MIPS_JUMP_SLOT.
(bfd_elf64_bfd_reloc_name_lookup): Handle "R_MIPS_COPY" and
"R_MIPS_JUMP_SLOT".
(mips_elf64_rtype_to_howto): Handle R_MIPS_COPY and R_MIPS_JUMP_SLOT.
(elf_backend_rela_plts_and_copies_p, elf_backend_plt_readonly)
(elf_backend_plt_sym_val): Define.
* elfxx-mips.h (_bfd_mips_vxworks_adjust_dynamic_symbol): Delete.
(_bfd_mips_elf_use_plts_and_copy_relocs, _bfd_mips_elf_init_stubs)
(_bfd_mips_elf_plt_sym_val, _bfd_mips_post_process_headers): Declare.
* elfxx-mips.c (mips_elf_la25_stub): New structure.
(LA25_LUI, LA25_J, LA25_ADDIU): New macros.
(mips_elf_link_hash_entry): Add "la25_stubs", "has_static_relocs"
and "has_nonpic_branches" fields. Remove "is_relocation_target" and
"is_branch_target".
(mips_elf_link_hash_table): Add blank lines. Add
"use_plts_and_copy_relocs", "reserved_gotno", "strampoline",
"la25_stubs" and "add_stub_section" fields.
(mips_htab_traverse_info): New structure.
(PIC_OBJECT_P, MIPS_ELF_LOAD_WORD): New macros.
(MIPS_RESERVED_GOTNO): Delete.
(mips_o32_exec_plt0_entry, mips_n32_exec_plt0_entry)
(mips_n64_exec_plt0_entry, mips_exec_plt_entry): New tables.
(mips_elf_link_hash_newfunc): Update after the changes to
mips_elf_link_hash_entry.
(mips_elf_check_mips16_stubs): Replace the DATA parameter with
an INFO parameter. Don't look through warnings symbols here;
do it in mips_elf_check_symbols instead.
(mips_elf_create_stub_symbol): New function.
(mips_elf_la25_stub_hash, mips_elf_la25_stub_eq): New functions.
(_bfd_mips_elf_init_stubs, mips_elf_local_pic_function_p): Likewise.
(mips_elf_add_la25_intro, mips_elf_add_la25_trampoline): Likewise.
(mips_elf_add_la25_stub, mips_elf_check_symbols): New functions.
(mips_elf_gotplt_index): Check for VxWorks.
(mips_elf_output_dynamic_relocation): Take the relocation index
as an extra parameter. Do not increment reloc_count here.
(mips_elf_initialize_tls_slots): Update the calls to
mips_elf_output_dynamic_relocation accordingly.
(mips_elf_multi_got): Use htab->reserved_gotno instead of
MIPS_RESERVED_GOTNO.
(mips_elf_create_got_section): Don't allocate reserved GOT
entries here. Unconditionally create .got.plt, but don't
set its alignment here.
(mips_elf_relocation_needs_la25_stub): New function.
(mips_elf_calculate_relocation): Redirect branches and jumps to
a non-PIC stub if one exists. Check !h->has_static_relocs instead
of !htab->is_vxworks when deciding whether to create dynamic
relocations for R_MIPS_32, R_MIPS_REL32 and R_MIPS_64.
(_bfd_mips_elf_create_dynamic_sections): Unconditionally call
_bfd_elf_create_dynamic_sections. Unconditionally set up
htab->splt and htab->sdynbss. Set htab->srelplt to ".rel.plt"
if !htab->is_vxworks. Add non-VxWorks values of
htab->plt_header_size and htab->plt_entry_size.
(_bfd_mips_elf_check_relocs): Set pointer_equality_needed for
non-branch static relocations. Set has_nonpic_branches when an la25
stub might be required. Set can_make_dynamic_p to TRUE if R_MIPS_32,
R_MIPS_REL32 and R_MIPS_64 relocations can be made dynamic,
rather than duplicating the condition. Do not make them dynamic
for read-only sections in non-PIC executable objects.
Do not protect this code with dynobj == NULL || htab->sgot == NULL;
handle each group of cases separately. Add a default case that
sets has_static_relocs for non-GOT relocations that cannot be
made dynamic. Don't set is_relocation_target and is_branch_target.
Reject non-PIC static relocations in shared objects.
(_bfd_mips_vxworks_adjust_dynamic_symbol): Fold into...
(_bfd_mips_elf_adjust_dynamic_symbol): ...here, using
htab->use_plts_and_copy_relocs instead of htab->is_vxworks
to select PLT and copy-reloc handling. Set the alignment of
.plt and .got.plt when allocating the first entry. Generalize
code to handle REL as well as RELA sections and 64-bit as well as
32-bit GOT entries. Complain if we find a static-only reloc
against an externally-defined symbol and if we cannot create
dynamic relocations for it. Allocate copy relocs using
mips_elf_allocate_dynamic_relocations on non-VxWorks targets.
Set possibly_dynamic_relocs to 0 when using PLTs or copy relocs.
Skip reserved .got.plt entries.
(_bfd_mips_elf_always_size_sections): Use mips_elf_check_symbols
instead of mips_elf_check_mips16_stubs to process each symbol.
Do the traversal for relocatable objects too.
(mips_elf_lay_out_got): Use htab->reserved_gotno instead of
MIPS_RESERVED_GOTNO.
(_bfd_mips_elf_size_dynamic_sections): Exclude sdynbss if it
is empty. Extend the DT_PLTREL, DT_JMPREL and DT_PLTRELSZ handling
to non-VxWorks targets. Only add DT_REL{,A}, DT_REL{,A}SZ and
DT_REL{,A}ENT if .rel.dyn is nonempty. Create a symbol for the
PLT. Allocate a nop at the end of the PLT. Allocate DT_MIPS_PLTGOT.
(mips_elf_create_la25_stub_info): New function.
(_bfd_mips_elf_finish_dynamic_symbol): Write out PLT entries
and copy relocs where necessary. Check pointer_equality_needed.
(mips_finish_exec_plt): New function.
(_bfd_mips_elf_finish_dynamic_sections): Always set DT_PLTGOT
to the beginning of htab->sgot. Use htab->reserved_gotno instead
of MIPS_RESERVED_GOTNO. Assert htab->use_plts_and_copy_relocs
instead of htab->is_vxworks for DT_PLTREL, DT_PLTRELSZ and DT_JMPREL.
Set DT_PLTREL to DT_REL instead of DT_RELA on non-VxWorks targets.
Use mips_finish_exec_plt to create non-VxWorks PLT headers. Set
DT_MIPS_PLTGOT.
(_bfd_mips_elf_copy_indirect_symbol): Copy has_static_relocs
from the indirect symbol to the direct symbol. Also copy
has_nonpic_branches for indirect symbols.
(_bfd_mips_elf_get_target_dtag): Handle DT_MIPS_PLTGOT and
DT_MIPS_RWPLT.
(_bfd_mips_elf_link_hash_table_create): Initialize the new
mips_elf_link_hash_table fields.
(_bfd_mips_vxworks_link_hash_table_create): Set
use_plts_and_copy_relocs to TRUE. Use TRUE rather than 1
when setting is_vxworks.
(_bfd_mips_elf_use_plts_and_copy_relocs): New function.
(_bfd_mips_elf_final_link): Call mips_elf_create_la25_stub for
each la25_stub.
(_bfd_mips_elf_merge_private_bfd_data): Treat dynamic objects
as PIC. Generalize message about linking PIC and non-PIC.
(_bfd_mips_elf_plt_sym_val, _bfd_mips_post_process_headers): New
functions.
* reloc.c: Update comment near BFD_RELOC_MIPS_JUMP_SLOT.
* bfd-in2.h: Regenerated.
2008-08-08 Richard Sandiford <rdsandiford@googlemail.com>
Daniel Jacobowitz <dan@codesourcery.com>
Catherine Moore <clm@codesourcery.com>
Mark Shinwell <shinwell@codesourcery.com>
* readelf.c (get_mips_symbol_other): Handle STO_MIPS_PLT and
STO_MIPS_PIC.
(slurp_rela_relocs, slurp_rel_relocs): Handle MIPS ELF64 here.
(dump_relocations, debug_apply_relocations): Don't handle it here.
(get_mips_dynamic_type): Handle DT_MIPS_PLTGOT and DT_MIPS_RWPLT.
(print_mips_pltgot_entry): New function.
(process_mips_specific): Dump the PLT GOT.
2008-08-08 Richard Sandiford <rdsandiford@googlemail.com>
Daniel Jacobowitz <dan@codesourcery.com>
* config/tc-mips.c (OPTION_CALL_NONPIC): New macro.
(OPTION_NON_SHARED, OPTION_XGOT, OPTION_MABI, OPTION_32)
(OPTION_N32, OPTION_64, OPTION_MDEBUG, OPTION_NO_MDEBUG)
(OPTION_PDR, OPTION_NO_PDR, OPTION_MVXWORKS_PIC): Bump by 1.
(md_longopts): Add -call_nonpic.
(md_parse_option): Handle OPTION_CALL_NONPIC.
(md_show_usage): Add -call_nonpic.
2008-08-08 Richard Sandiford <rdsandiford@googlemail.com>
* gas/mips/call-nonpic-1.s, gas/mips/call-nonpic-1.d: New test.
* gas/mips/mips.exp: Run it.
2008-08-08 Richard Sandiford <rdsandiford@googlemail.com>
Daniel Jacobowitz <dan@codesourcery.com>
Catherine Moore <clm@codesourcery.com>
Mark Shinwell <shinwell@codesourcery.com>
* mips.h (STO_MIPS_PLT, ELF_ST_IS_MIPS_PLT, ELF_ST_SET_MIPS_PLT)
(STO_MIPS_PIC, DT_MIPS_PLTGOT, DT_MIPS_RWPLT): New macros.
2008-08-08 Richard Sandiford <rdsandiford@googlemail.com>
Daniel Jacobowitz <dan@codesourcery.com>
* emulparams/elf32bmip.sh (GOT): Define, moving .got.plt to...
(OTHER_RELRO_SECTIONS, OTHER_READWRITE_SECTIONS): ...one of these
two variables.
* emulparams/elf32bmipn32-defs.sh: Likewise.
* emultempl/mipself.em: Include ldctor.h, elf/mips.h and elfxx-mips.h.
(is_mips_elf): New macro.
(stub_file, stub_bfd): New variables.
(hook_stub_info): New structure.
(hook_in_stub): New function.
(mips_add_stub_section): Likewise.
(mips_create_output_section_statements): Likewise.
(mips_before_allocation): Likewise.
(real_func): New variable.
(mips_for_each_input_file_wrapper): New function.
(mips_lang_for_each_input_file): Likewise.
(lang_for_each_input_file): Define.
(LDEMUL_BEFORE_ALLOCATION): Likewise.
(LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS): Likewise.
2008-08-08 Richard Sandiford <rdsandiford@googlemail.com>
Daniel Jacobowitz <dan@codesourcery.com>
* ld-mips-elf/mips16-pic-3a.s,
ld-mips-elf/mips16-pic-3b.s,
ld-mips-elf/mips16-pic-3.dd,
ld-mips-elf/mips16-pic-3.gd,
ld-mips-elf/mips16-pic-3.rd,
ld-mips-elf/mips16-pic-3.inc,
ld-mips-elf/pic-and-nonpic-1a.s,
ld-mips-elf/pic-and-nonpic-1b.s,
ld-mips-elf/pic-and-nonpic-1.ld,
ld-mips-elf/pic-and-nonpic-1.dd,
ld-mips-elf/pic-and-nonpic-1.nd,
ld-mips-elf/pic-and-nonpic-1-rel.dd,
ld-mips-elf/pic-and-nonpic-1-rel.nd,
ld-mips-elf/pic-and-nonpic-2a.s,
ld-mips-elf/pic-and-nonpic-2b.s,
ld-mips-elf/pic-and-nonpic-2.d,
ld-mips-elf/pic-and-nonpic-3a.s,
ld-mips-elf/pic-and-nonpic-3a.ld,
ld-mips-elf/pic-and-nonpic-3a.dd,
ld-mips-elf/pic-and-nonpic-3a.gd,
ld-mips-elf/pic-and-nonpic-3a.sd,
ld-mips-elf/pic-and-nonpic-3b.s,
ld-mips-elf/pic-and-nonpic-3b.ld,
ld-mips-elf/pic-and-nonpic-3b.ad,
ld-mips-elf/pic-and-nonpic-3b.dd,
ld-mips-elf/pic-and-nonpic-3b.gd,
ld-mips-elf/pic-and-nonpic-3b.nd,
ld-mips-elf/pic-and-nonpic-3b.pd,
ld-mips-elf/pic-and-nonpic-3b.rd,
ld-mips-elf/pic-and-nonpic-3b.sd,
ld-mips-elf/pic-and-nonpic-3-error.d,
ld-mips-elf/pic-and-nonpic-4a.s,
ld-mips-elf/pic-and-nonpic-4b.s,
ld-mips-elf/pic-and-nonpic-4b.ld,
ld-mips-elf/pic-and-nonpic-4b.ad,
ld-mips-elf/pic-and-nonpic-4b.dd,
ld-mips-elf/pic-and-nonpic-4b.gd,
ld-mips-elf/pic-and-nonpic-4b.nd,
ld-mips-elf/pic-and-nonpic-4b.rd,
ld-mips-elf/pic-and-nonpic-4b.sd,
ld-mips-elf/pic-and-nonpic-4-error.d,
ld-mips-elf/pic-and-nonpic-5a.s,
ld-mips-elf/pic-and-nonpic-5b.s,
ld-mips-elf/pic-and-nonpic-5b.ld,
ld-mips-elf/pic-and-nonpic-5b.ad,
ld-mips-elf/pic-and-nonpic-5b.dd,
ld-mips-elf/pic-and-nonpic-5b.gd,
ld-mips-elf/pic-and-nonpic-5b.nd,
ld-mips-elf/pic-and-nonpic-5b.rd,
ld-mips-elf/pic-and-nonpic-5b.sd,
ld-mips-elf/pic-and-nonpic-5b.pd,
ld-mips-elf/pic-and-nonpic-6.ld,
ld-mips-elf/pic-and-nonpic-6-o32a.s,
ld-mips-elf/pic-and-nonpic-6-o32b.s,
ld-mips-elf/pic-and-nonpic-6-o32c.s,
ld-mips-elf/pic-and-nonpic-6-o32.ad,
ld-mips-elf/pic-and-nonpic-6-o32.dd,
ld-mips-elf/pic-and-nonpic-6-o32.gd,
ld-mips-elf/pic-and-nonpic-6-o32.nd,
ld-mips-elf/pic-and-nonpic-6-o32.pd,
ld-mips-elf/pic-and-nonpic-6-o32.rd,
ld-mips-elf/pic-and-nonpic-6-o32.sd,
ld-mips-elf/pic-and-nonpic-6-n32a.s,
ld-mips-elf/pic-and-nonpic-6-n32b.s,
ld-mips-elf/pic-and-nonpic-6-n32c.s,
ld-mips-elf/pic-and-nonpic-6-n32.ad,
ld-mips-elf/pic-and-nonpic-6-n32.dd,
ld-mips-elf/pic-and-nonpic-6-n32.gd,
ld-mips-elf/pic-and-nonpic-6-n32.nd,
ld-mips-elf/pic-and-nonpic-6-n32.pd,
ld-mips-elf/pic-and-nonpic-6-n32.rd,
ld-mips-elf/pic-and-nonpic-6-n32.sd,
ld-mips-elf/pic-and-nonpic-6-n64a.s,
ld-mips-elf/pic-and-nonpic-6-n64b.s,
ld-mips-elf/pic-and-nonpic-6-n64c.s,
ld-mips-elf/pic-and-nonpic-6-n64.ad,
ld-mips-elf/pic-and-nonpic-6-n64.dd,
ld-mips-elf/pic-and-nonpic-6-n64.gd,
ld-mips-elf/pic-and-nonpic-6-n64.nd,
ld-mips-elf/pic-and-nonpic-6-n64.pd,
ld-mips-elf/pic-and-nonpic-6-n64.rd,
ld-mips-elf/pic-and-nonpic-6-n64.sd: New tests.
* ld-mips-elf/mips-elf.exp: Run them.
Alan Modra
Mihailo Stojanovic
Matthew Fortune
Maciej W. Rozycki
Maciej W. Rozycki
H.J. Lu
Guy Martin
Maciej W. Rozycki
James Lemke
Nick Clifton
Daniel Jacobowitz
Roland McGrath
Richard Sandiford
Chris Demetriou