Implement the relaxation of MIPS16 PC-relative synthetic LA, DLA, LW and
LD instructions to an equivalent sequence of instructions produced where
the address operand requested is out of range, absolute or requires
linker relocation, for ABIs that use 32-bit addressing and non-PIC code.
The sequence generated uses the register specified for the destination
operand as a temporary and begins with LI to load the high 16-bit part
of the address, then continues with SLL by 16 bits to move that part
into place and finally completes with a suitable operation corresponding
to the synthetic instruction used, one of: 2-argument ADDIU, 2-argument
DADDIU, absolute LW, and absolute LD respectively, providing the low
16-bit part of the address. All instructions use the extended encoding.
As a special exception accept absolute addresses for relaxation even in
PIC code.
For example:
la $2, 0x12345678
produces code as:
li $2, 0x1234
sll $2, $2, 16
addiu $2, 0x5678
would.
Where linker relocation is required emit an R_MIPS16_HI16 relocation on
the initial LI instruction and an R_MIPS16_LO16 relocation on the final
operation.
For example (where `foo' is not local):
lw $3, foo
produces code as:
li $3, %hi(foo)
sll $3, $3, 16
lw $3, %lo(foo)($3)
would.
Emit assembly warnings as appropriate where this new relaxation triggers
in the `nomacro' mode or for an instruction manually placed in a branch
delay slot in the `noreorder' mode. Refrain from relaxation where an
explicit instruction size suffix has been used and in the `noautoextend'
mode.
gas/
* config/tc-mips.c (RELAX_MIPS16_ENCODE): Add `pic', `sym32' and
`nomacro' flags.
(RELAX_MIPS16_PIC, RELAX_MIPS16_SYM32, RELAX_MIPS16_NOMACRO):
New macros.
(RELAX_MIPS16_USER_SMALL, RELAX_MIPS16_USER_EXT)
(RELAX_MIPS16_DSLOT, RELAX_MIPS16_JAL_DSLOT)
(RELAX_MIPS16_EXTENDED, RELAX_MIPS16_MARK_EXTENDED)
(RELAX_MIPS16_CLEAR_EXTENDED, RELAX_MIPS16_ALWAYS_EXTENDED)
(RELAX_MIPS16_MARK_ALWAYS_EXTENDED)
(RELAX_MIPS16_CLEAR_ALWAYS_EXTENDED): Shift bits.
(RELAX_MIPS16_MACRO, RELAX_MIPS16_MARK_MACRO)
(RELAX_MIPS16_CLEAR_MACRO): New macros.
(append_insn): Pass `mips_pic', HAVE_32BIT_SYMBOLS and
`mips_opts.warn_about_macros' settings to RELAX_MIPS16_ENCODE.
(mips16_macro_frag): New function.
(md_estimate_size_before_relax): Handle HI16/LO16 relaxation.
(mips_relax_frag): Likewise.
(md_convert_frag): Likewise.
* testsuite/gas/mips/mips16@relax-swap3.d: Remove error output,
add dump patterns.
* testsuite/gas/mips/mips16e@relax-swap3.d: New test
subarchitecture.
* testsuite/gas/mips/micromips@relax-swap3.d: Remove trailing
NOP padding.
* testsuite/gas/mips/mips16-pcrel-reloc-2.d: Remove error
output, add dump patterns.
* testsuite/gas/mips/mips16-pcrel-reloc-3.d: Remove error
output, add dump patterns.
* testsuite/gas/mips/mips16-pcrel-reloc-6.d: Remove error
output, add dump patterns.
* testsuite/gas/mips/mips16-pcrel-reloc-7.d: Remove error
output, add dump patterns.
* testsuite/gas/mips/mips16-pcrel-addend-2.d: Remove error
output, add dump patterns.
* testsuite/gas/mips/mips16-pcrel-addend-3.d: Remove error
output, add dump patterns.
* testsuite/gas/mips/mips16-pcrel-absolute.d: Remove error
output, add dump patterns.
* testsuite/gas/mips/mips16-pcrel-absolute-1.d: Remove error
output, add dump patterns.
* testsuite/gas/mips/mips16@relax-swap3.l: Remove file.
* testsuite/gas/mips/mips16-pcrel-reloc-2.l: Remove file.
* testsuite/gas/mips/mips16-pcrel-reloc-3.l: Remove file.
* testsuite/gas/mips/mips16-pcrel-reloc-6.l: Remove file.
* testsuite/gas/mips/mips16-pcrel-reloc-7.l: Remove file.
* testsuite/gas/mips/mips16-pcrel-addend-2.l: Remove file.
* testsuite/gas/mips/mips16-pcrel-addend-3.l: Remove file.
* testsuite/gas/mips/mips16-pcrel-absolute.l: Remove file.
* testsuite/gas/mips/mips16-pcrel-absolute-1.l: Remove file.
* testsuite/gas/mips/relax-swap3.s: Adjust trailing padding.
* testsuite/gas/mips/mips16-pcrel-0.d: New test.
* testsuite/gas/mips/mips16-pcrel-1.d: New test.
* testsuite/gas/mips/mips16-pcrel-2.d: New test.
* testsuite/gas/mips/mips16-pcrel-3.d: New test.
* testsuite/gas/mips/mips16-pcrel-4.d: New test.
* testsuite/gas/mips/mips16-pcrel-5.d: New test.
* testsuite/gas/mips/mips16-pcrel-pic-0.d: New test.
* testsuite/gas/mips/mips16-pcrel-pic-1.d: New test.
* testsuite/gas/mips/mips16-pcrel-n32-0.d: New test.
* testsuite/gas/mips/mips16-pcrel-n32-1.d: New test.
* testsuite/gas/mips/mips16-pcrel-n64-sym32-0.d: New test.
* testsuite/gas/mips/mips16-pcrel-n64-sym32-1.d: New test.
* testsuite/gas/mips/mips16-pcrel-n64-0.d: New test.
* testsuite/gas/mips/mips16-pcrel-n64-1.d: New test.
* testsuite/gas/mips/mips16-pcrel-delay-0.d: New test.
* testsuite/gas/mips/mips16-pcrel-delay-1.d: New test.
* testsuite/gas/mips/mips16-pcrel-addend-4.d: New test.
* testsuite/gas/mips/mips16-pcrel-addend-5.d: New test.
* testsuite/gas/mips/mips16-pcrel-addend-6.d: New test.
* testsuite/gas/mips/mips16-pcrel-addend-7.d: New test.
* testsuite/gas/mips/mips16-pcrel-addend-8.d: New test.
* testsuite/gas/mips/mips16-pcrel-addend-9.d: New test.
* testsuite/gas/mips/mips16-pcrel-addend-pic-8.d: New test.
* testsuite/gas/mips/mips16-pcrel-addend-pic-9.d: New test.
* testsuite/gas/mips/mips16-pcrel-addend-n32-8.d: New test.
* testsuite/gas/mips/mips16-pcrel-addend-n32-9.d: New test.
* testsuite/gas/mips/mips16-pcrel-addend-n64-sym32-8.d: New test.
* testsuite/gas/mips/mips16-pcrel-addend-n64-sym32-9.d: New test.
* testsuite/gas/mips/mips16-pcrel-addend-n64-8.d: New test.
* testsuite/gas/mips/mips16-pcrel-addend-n64-9.d: New test.
* testsuite/gas/mips/mips16-pcrel-absolute-2.d: New test.
* testsuite/gas/mips/mips16-pcrel-absolute-3.d: New test.
* testsuite/gas/mips/mips16-pcrel-absolute-4.d: New test.
* testsuite/gas/mips/mips16-pcrel-absolute-5.d: New test.
* testsuite/gas/mips/mips16-pcrel-absolute-6.d: New test.
* testsuite/gas/mips/mips16-pcrel-absolute-7.d: New test.
* testsuite/gas/mips/mips16-pcrel-absolute-pic-4.d: New test.
* testsuite/gas/mips/mips16-pcrel-absolute-pic-6.d: New test.
* testsuite/gas/mips/mips16-pcrel-absolute-n32-4.d: New test.
* testsuite/gas/mips/mips16-pcrel-absolute-n32-6.d: New test.
* testsuite/gas/mips/mips16-pcrel-absolute-n64-4.d: New test.
* testsuite/gas/mips/mips16-pcrel-absolute-n64-6.d: New test.
* testsuite/gas/mips/mips16-pcrel-absolute-n64-sym32-4.d: New
test.
* testsuite/gas/mips/mips16-pcrel-absolute-n64-sym32-6.d: New
test.
* testsuite/gas/mips/mips16-pcrel-absolute-pic-n32-4.d: New
test.
* testsuite/gas/mips/mips16-pcrel-absolute-pic-n32-6.d: New
test.
* testsuite/gas/mips/mips16-pcrel-absolute-pic-n64-4.d: New
test.
* testsuite/gas/mips/mips16-pcrel-absolute-pic-n64-6.d: New
test.
* testsuite/gas/mips/mips16-pcrel-absolute-pic-n64-sym32-4.d:
New test.
* testsuite/gas/mips/mips16-pcrel-absolute-pic-n64-sym32-6.d:
New test.
* testsuite/gas/mips/mips16-pcrel-0.l: New stderr output.
* testsuite/gas/mips/mips16-pcrel-1.l: New stderr output.
* testsuite/gas/mips/mips16-pcrel-2.l: New stderr output.
* testsuite/gas/mips/mips16-pcrel-3.l: New stderr output.
* testsuite/gas/mips/mips16-pcrel-4.l: New stderr output.
* testsuite/gas/mips/mips16-pcrel-5.l: New stderr output.
* testsuite/gas/mips/mips16-pcrel-delay-0.l: New stderr output.
* testsuite/gas/mips/mips16-pcrel-delay-1.l: New stderr output.
* testsuite/gas/mips/mips16-pcrel-addend-8.l: New stderr output.
* testsuite/gas/mips/mips16-pcrel-addend-9.l: New stderr output.
* testsuite/gas/mips/mips16-pcrel-absolute-4.l: New stderr
output.
* testsuite/gas/mips/mips16-pcrel-absolute-6.l: New stderr
output.
* testsuite/gas/mips/mips16-pcrel-0.s: New test source.
* testsuite/gas/mips/mips16-pcrel-1.s: New test source.
* testsuite/gas/mips/mips16-pcrel-2.s: New test source.
* testsuite/gas/mips/mips16-pcrel-3.s: New test source.
* testsuite/gas/mips/mips16-pcrel-4.s: New test source.
* testsuite/gas/mips/mips16-pcrel-5.s: New test source.
* testsuite/gas/mips/mips16-pcrel-delay-0.s: New test source.
* testsuite/gas/mips/mips16-pcrel-delay-1.s: New test source.
* testsuite/gas/mips/mips16-pcrel-addend-4.s: New test source.
* testsuite/gas/mips/mips16-pcrel-addend-5.s: New test source.
* testsuite/gas/mips/mips16-pcrel-addend-6.s: New test source.
* testsuite/gas/mips/mips16-pcrel-addend-7.s: New test source.
* testsuite/gas/mips/mips16-pcrel-addend-8.s: New test source.
* testsuite/gas/mips/mips16-pcrel-addend-9.s: New test source.
* testsuite/gas/mips/mips16-pcrel-absolute-2.s: New test.
* testsuite/gas/mips/mips16-pcrel-absolute-3.s: New test.
* testsuite/gas/mips/mips16-pcrel-absolute-4.s: New test.
* testsuite/gas/mips/mips16-pcrel-absolute-5.s: New test.
* testsuite/gas/mips/mips16-pcrel-absolute-6.s: New test.
* testsuite/gas/mips/mips16-pcrel-absolute-7.s: New test.
* testsuite/gas/mips/mips.exp: Run the new tests.
ld/
* testsuite/ld-mips-elf/mips16-pcrel-0.d: New test.
* testsuite/ld-mips-elf/mips16-pcrel-1.d: New test.
* testsuite/ld-mips-elf/mips16-pcrel-addend-2.d: New test.
* testsuite/ld-mips-elf/mips16-pcrel-addend-6.d: New test.
* testsuite/ld-mips-elf/mips16-pcrel-n32-0.d: New test.
* testsuite/ld-mips-elf/mips16-pcrel-n32-1.d: New test.
* testsuite/ld-mips-elf/mips16-pcrel-n64-sym32-0.d: New test.
* testsuite/ld-mips-elf/mips16-pcrel-n64-sym32-1.d: New test.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.
Complement commit 88a7ef1689 ("MIPS16/GAS: Restore unsupported
relocation diagnostics") and also propagate constant expressions, either
already reduced from absolute symbol references or created from literals
in the first place, used as a PC-relative operand with the MIPS16 LA,
LW, DLA and LD synthetic instructions to relaxation, matching the way
forward absolute symbol references have been handled as from the commit
referred and letting relaxation produce any necessary relocations, if
possible, for the absolute value requested to be reproduced at the run
time.
Call `symbol_append' for any expression symbol created for the purpose
of MIPS16 relaxation as with constant expressions now propagated from
earlier on such symbols may make it through and have R_MIPS16_PC16_S1
relocations emitted against, and therefore need to appear in the symbol
table produced.
gas/
* config/tc-mips.c (append_insn): Call `symbol_append' for any
expression symbol created for MIPS16 relaxation.
(match_mips16_insn): Don't encode a constant value as an
immediate with a PC-relative operand.
* testsuite/gas/mips/mips16-pcrel-absolute-1.d: New test.
* testsuite/gas/mips/mips16-branch-absolute-1.d: New test.
* testsuite/gas/mips/mips16-branch-absolute-2.d: New test.
* testsuite/gas/mips/mips16-branch-absolute-addend-1.d: New
test.
* testsuite/gas/mips/mips16-branch-absolute-n32-1.d: New test.
* testsuite/gas/mips/mips16-branch-absolute-n32-2.d: New test.
* testsuite/gas/mips/mips16-branch-absolute-addend-n32-1.d: New
test.
* testsuite/gas/mips/mips16-branch-absolute-n64-1.d: New test.
* testsuite/gas/mips/mips16-branch-absolute-n64-2.d: New test.
* testsuite/gas/mips/mips16-branch-absolute-addend-n64-1.d: New
test.
* testsuite/gas/mips/mips16-pcrel-absolute-1.l: New stderr
output.
* testsuite/gas/mips/mips16-pcrel-absolute-1.s: New test source.
* testsuite/gas/mips/mips16-branch-absolute-1.s: New test
source.
* testsuite/gas/mips/mips16-branch-absolute-2.s: New test
source.
* testsuite/gas/mips/mips16-branch-absolute-addend-1.s: New test
source.
* testsuite/gas/mips/mips.exp: Run the new tests.
ld/
* testsuite/ld-mips-elf/mips16-branch-absolute-1.d: New test.
* testsuite/ld-mips-elf/mips16-branch-absolute-2.d: New test.
* testsuite/ld-mips-elf/mips16-branch-absolute-addend-1.d: New
test.
* testsuite/ld-mips-elf/mips16-branch-absolute-n32-1.d: New
test.
* testsuite/ld-mips-elf/mips16-branch-absolute-n32-2.d: New
test.
* testsuite/ld-mips-elf/mips16-branch-absolute-addend-n32-1.d:
New test.
* testsuite/ld-mips-elf/mips16-branch-absolute-n64-1.d: New
test.
* testsuite/ld-mips-elf/mips16-branch-absolute-n64-2.d: New
test.
* testsuite/ld-mips-elf/mips16-branch-absolute-addend-n64-1.d:
New test.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.
Complement commit e17b0c351f ("MIPS/BFD: Respect the ELF gABI dynamic
symbol table sort requirement") and correct an inconsistency in dynamic
symbol accounting data causing an assertion failure in the MIPS backend:
ld: BFD (GNU Binutils) 2.28.51.20170330 assertion fail
../../binutils-gdb/bfd/elfxx-mips.c:3860
in the course of making a GOT entry in a static binary to satisfy a GOT
relocation present in input, due to the local dynamic symbol count not
having been established.
To do so let backends request `_bfd_elf_link_renumber_dynsyms' to be
always called, rather than where a dynamic binary is linked only, and
then make this request in the MIPS backend.
bfd/
PR ld/21334
* elf-bfd.h (elf_backend_data): Add `always_renumber_dynsyms'
member.
* elfxx-target.h [!elf_backend_always_renumber_dynsyms]
(elf_backend_always_renumber_dynsyms): Define.
(elfNN_bed): Initialize `always_renumber_dynsyms' member.
* elfxx-mips.h (elf_backend_always_renumber_dynsyms): Define.
* elflink.c (bfd_elf_size_dynamic_sections): Also call
`_bfd_elf_link_renumber_dynsyms' if the backend has requested
it.
(bfd_elf_size_dynsym_hash_dynstr): Likewise.
ld/
PR ld/21334
* testsuite/ld-mips-elf/pr21334.dd: New test.
* testsuite/ld-mips-elf/pr21334.gd: New test.
* testsuite/ld-mips-elf/pr21334.ld: New test linker script.
* testsuite/ld-mips-elf/pr21334.s: New test source.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.
Complement commit 3807734dbe ("PR ld/15428: MIPS/LD/testsuite:
Un-KFAIL `__ehdr_start' test 2") and join tests that do not need to be
split anymore.
ld/
* testsuite/ld-mips-elf/mips-elf.exp: Join `__ehdr_start' tests.
Interpret the `jalr $0, $25' instruction encoding with an R_MIPS_JALR
relocation attached as an alias to `jr $25' and convert the jump to an
equivalent branch where possible, consequently covering the MIPSr6
architecture for the purpose of this optimization too.
bfd/
* elfxx-mips.c (mips_elf_perform_relocation): Also handle the
`jalr $0, $25' instruction encoding.
gas/
* testsuite/gas/mips/jalr4.s: Add `jalr $0, $25' instructions.
* testsuite/gas/mips/jalr4.d: Adjust accordingly. Remove MIPSr6
encoding patterns.
* testsuite/gas/mips/jalr4-n64.d: Likewise.
* testsuite/gas/mips/mipsr6@jalr4.d: New test.
* testsuite/gas/mips/mipsr6@jalr4-n32.d: New test.
* testsuite/gas/mips/mipsr6@jalr4-n64.d: New test.
ld/
* testsuite/ld-mips-elf/jalr4.dd: Adjust for `jalr $0, $25'
instructions.
* testsuite/ld-mips-elf/jalr4-r6.dd: New test.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new test.
Discard R_MIPS_JALR and R_MICROMIPS_JALR relocations associated with
jumps that cannot be converted to an equivalent branch right away in
`mips_elf_calculate_relocation' rather than letting them through to
`mips_elf_perform_relocation'. This includes cross-mode jumps which
need to flip the ISA bit or jumps to a misaligned location that cannot
be encoded with a branch, in addition to preemptible symbol references
already handled.
Cross-mode jumps are actually already rejected as the conversion is made
in `mips_elf_perform_relocation', so in this case this change only saves
some processing. Jumps to a misaligned location are however converted,
with bits causing misalignment lost, making resulting code functionally
different even if the lone effect is avoiding an address error exception
with an instruction fetch at the jump destination requested.
Add test cases suitable, also including GAS verification to confirm that
the JALR relocations explicitly requested have indeed been output in the
intermediate objects used.
bfd/
* elfxx-mips.c (mips_elf_calculate_relocation) <R_MIPS_JALR>
<R_MICROMIPS_JALR>: Discard relocation if `cross_mode_jump_p'
or misaligned.
gas/
* testsuite/gas/mips/jalr4.d: New test.
* testsuite/gas/mips/jalr4-n32.d: New test.
* testsuite/gas/mips/jalr4-n64.d: New test.
* testsuite/gas/mips/jalr4.s: New test source.
* testsuite/gas/mips/mips.exp: Run the new tests.
ld/
* testsuite/ld-mips-elf/jalr4.dd: New test.
* 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.
Correct a regression from commit 8614eeee67 ("Traditional MIPS
patches"), <https://sourceware.org/ml/binutils/2000-07/msg00018.html>,
which caused symbols in linkonce or what is these days known as comdat
sections to be treated as external for the purpose of PIC relocation
generation even if their binding remains STB_LOCAL. This in turn
disabled GOT16/LO16 relocation pairing with references to such symbols,
as no complementing LO16 relocation is expected for external GOT16
references in the o32 ABI, which ultimately leads to link errors, e.g.:
ld: comdat-reloc.o: Can't find matching LO16 reloc against `foo' for R_MIPS_GOT16 at 0x24 in section `.text.bar[bar]'
as with the LD test case included with this change.
Revert the special case for symbols in comdat sections then, making code
actually match `adjust_reloc_syms' as indicated in its explanatory
comment, and adjust calling code accordingly. Also bring back the
corresponding description of what now is `s_is_linkonce', lost with
commit 5f0fe04bc5 ("Improved MIPS16/MIPS32 code intermixing for
gas."), <https://www.sourceware.org/ml/binutils/2006-07/msg00039.html>.
gas/
PR gas/20649
* config/tc-mips.c (pic_need_relax): Don't check for linkonce
symbols, remove the `segtype' parameter.
(mips_frob_file, md_estimate_size_before_relax): Adjust
accordingly.
(s_is_linkonce): Add an explanatory comment.
* testsuite/gas/mips/comdat-reloc.d: New test.
* testsuite/gas/mips/comdat-reloc.s: New test source.
* testsuite/gas/mips/mips.exp: Run the new test.
ld/
PR gas/20649
* testsuite/ld-mips-elf/mips-elf.exp: Add PIC comdat GOT16/LO16
relocation pairing link test.
Complement commit b75d42bce5 ("Fix mips segfault on GOT access of
absolute symbol") and unmark the `__ehdr_start' test 2 as known to fail
for the n32 and n64 ABIs, as with the change referred in place the
causing issue has been properly addressed and consequently the tests do
not fail anymore and neither are supposed to.
ld/
PR ld/15428
* testsuite/ld-mips-elf/mips-elf.exp: Un-KFAIL `__ehdr_start'
test 2.
Repeat `PIC and non-PIC test 1' checks for microMIPS LA25 stubs,
covering code generation and stub symbol annotation.
ld/
* testsuite/ld-mips-elf/pic-and-nonpic-1-micromips-rel.dd: New
test.
* testsuite/ld-mips-elf/pic-and-nonpic-1-micromips-rel.nd: New
test.
* testsuite/ld-mips-elf/pic-and-nonpic-1-micromips.dd: New test.
* testsuite/ld-mips-elf/pic-and-nonpic-1-micromips.nd: New test.
* testsuite/ld-mips-elf/pic-and-nonpic-1a-micromips.s: New test
source.
* testsuite/ld-mips-elf/pic-and-nonpic-1b-micromips.s: New test
source.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.
Complement:
commit 1bbce13264
Author: Maciej W. Rozycki <macro@linux-mips.org>
Date: Mon Jun 24 23:55:46 2013 +0000
<https://sourceware.org/ml/binutils/2013-06/msg00077.html>, ("MIPS:
Compressed PLT/stubs support"), and also choose between regular and
compressed PLT entries as appropriate for any branches referring.
bfd/
* elfxx-mips.c (mips_elf_calculate_relocation): Handle branches
in PLT compression selection.
(_bfd_mips_elf_check_relocs): Likewise.
ld/
* testsuite/ld-mips-elf/compressed-plt-1.s: Add branch support.
* testsuite/ld-mips-elf/compressed-plt-1a.s: Likewise.
* testsuite/ld-mips-elf/compressed-plt-1b.s: Likewise.
* testsuite/ld-mips-elf/compressed-plt-1-o32-branch.od: New
test.
* testsuite/ld-mips-elf/compressed-plt-1-o32-branch.rd: New
test.
* testsuite/ld-mips-elf/compressed-plt-1-o32-mips16-bronly.od:
New test.
* testsuite/ld-mips-elf/compressed-plt-1-o32-mips16-bronly.rd:
New test.
* testsuite/ld-mips-elf/compressed-plt-1-o32-mips16-branch.od:
New test.
* testsuite/ld-mips-elf/compressed-plt-1-o32-mips16-branch.rd:
New test.
* testsuite/ld-mips-elf/compressed-plt-1-o32-umips-bronly.od:
New test.
* testsuite/ld-mips-elf/compressed-plt-1-o32-umips-bronly.rd:
New test.
* testsuite/ld-mips-elf/compressed-plt-1-o32-umips-branch.od:
New test.
* testsuite/ld-mips-elf/compressed-plt-1-o32-umips-branch.rd:
New test.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.
Convert cross-mode regular MIPS and microMIPS BAL instructions to JALX,
similarly to how JAL instructions are converted.
bfd/
* elfxx-mips.c (mips_elf_perform_relocation): Convert cross-mode
BAL to JALX.
(_bfd_mips_elf_relocate_section) <bfd_reloc_outofrange>: Add a
corresponding error message.
gas/
* config/tc-mips.c (mips_force_relocation, mips_fix_adjustable):
Adjust comments for BAL to JALX linker conversion.
(fix_bad_cross_mode_branch_p): Accept cross-mode BAL.
* testsuite/gas/mips/unaligned-branch-1.l: Update error messages
expected.
* testsuite/gas/mips/unaligned-branch-micromips-1.l: Likewise.
* testsuite/gas/mips/branch-local-4.d: New test.
* testsuite/gas/mips/branch-local-n32-4.d: New test.
* testsuite/gas/mips/branch-local-n64-4.d: New test.
* testsuite/gas/mips/branch-addend.d: New test.
* testsuite/gas/mips/branch-addend-n32.d: New test.
* testsuite/gas/mips/branch-addend-n64.d: New test.
* testsuite/gas/mips/branch-local-4.s: New test source.
* testsuite/gas/mips/branch-addend.s: New test source.
* testsuite/gas/mips/mips.exp: Run the new tests.
ld/
* testsuite/ld-mips-elf/unaligned-branch-2.d: Update error
messages expected.
* testsuite/ld-mips-elf/unaligned-branch-r6-1.d: Likewise.
* testsuite/ld-mips-elf/unaligned-branch-mips16.d: Likewise.
* testsuite/ld-mips-elf/unaligned-branch-micromips.d: Likewise.
* testsuite/ld-mips-elf/bal-jalx-addend.d: New test.
* testsuite/ld-mips-elf/bal-jalx-local.d: New test.
* testsuite/ld-mips-elf/bal-jalx-pic.d: New test.
* testsuite/ld-mips-elf/bal-jalx-addend-n32.d: New test.
* testsuite/ld-mips-elf/bal-jalx-local-n32.d: New test.
* testsuite/ld-mips-elf/bal-jalx-pic-n32.d: New test.
* testsuite/ld-mips-elf/bal-jalx-addend-n64.d: New test.
* testsuite/ld-mips-elf/bal-jalx-local-n64.d: New test.
* testsuite/ld-mips-elf/bal-jalx-pic-n64.d: New test.
* testsuite/ld-mips-elf/unaligned-jalx-2.d: New test.
* testsuite/ld-mips-elf/unaligned-jalx-3.d: New test.
* testsuite/ld-mips-elf/unaligned-jalx-addend-2.d: New test.
* testsuite/ld-mips-elf/unaligned-jalx-addend-3.d: New test.
* testsuite/ld-mips-elf/unaligned-jalx-2.s: New test source.
* testsuite/ld-mips-elf/unaligned-jalx-3.s: New test source.
* testsuite/ld-mips-elf/unaligned-jalx-addend-2.s: New test
source.
* testsuite/ld-mips-elf/unaligned-jalx-addend-3.s: New test
source.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.
Verify that the ISA mode of branch targets is the same as the referring
relocation, so that an attempt to produce a branch between instructions
encoded in different ISA modes each causes an error rather than silently
producing non-functional code. Make sure that no symbol or addend bits
are silently truncated: terminate with an error if the relocation value
calculated cannot be encoded in the relocatable field of a branch; for
REL targets also applying to any intermediate addend.
Also make jump target's alignment verification consistent with that for
branches.
This change will require an update to some obscure handcoded assembly
sources which make branches to labels placed at data objects, however
for microMIPS code only. These labels will have to be updated with the
`.insn' directive for containing code to assemble and link successfully.
Such code is broken as any such labels have always been required by the
microMIPS architecture specification[1][2] to be annotated this way for
correct interpretation, and with our old code missing `.insn' directives
caused labels to present different semantics depending on whether they
were referred with branch (ISA bit ignored) or other relocations (ISA
bit respected).
Enforcing these checks however will ensure errors in building software,
like mixed regular MIPS and microMIPS code links with branches between,
will be diagnosed at the build time rather than causing odd run-time
errors such as intermittent crashes. It will also let cross-mode BAL
instructions be converted to JALX instructions, with a separate change.
References:
[1] "MIPS Architecture for Programmers, Volume II-B: The microMIPS32
Instruction Set", MIPS Technologies, Inc., Document Number: MD00582,
Revision 5.04, January 15, 2014, Section 7.1 "Assembly-Level
Compatibility", p. 533
[2] "MIPS Architecture for Programmers, Volume II-B: The microMIPS64
Instruction Set", MIPS Technologies, Inc., Document Number: MD00594,
Revision 5.04, January 15, 2014, Section 8.1 "Assembly-Level
Compatibility", p. 623
bfd/
* elfxx-mips.c (b_reloc_p): Add R_MICROMIPS_PC16_S1,
R_MICROMIPS_PC10_S1 and R_MICROMIPS_PC7_S1.
(branch_reloc_p): New function.
(mips_elf_calculate_relocation): Handle ISA mode determination
for relocations against section symbols, against absolute
symbols and absolute relocations. Also set `*cross_mode_jump_p'
for branches.
<R_MIPS16_26, R_MIPS_26, R_MICROMIPS_26_S1>: Suppress alignment
checks for weak undefined symbols. Also check target alignment
within the same ISA mode.
<R_MIPS_PC16, R_MIPS_GNU_REL16_S2>: Handle cross-mode branches
in the alignment check.
<R_MICROMIPS_PC7_S1>: Add an alignment check.
<R_MICROMIPS_PC10_S1>: Likewise.
<R_MICROMIPS_PC16_S1>: Likewise.
(mips_elf_perform_relocation): Report a failure for unsupported
same-mode JALX instructions and cross-mode branches.
(_bfd_mips_elf_relocate_section) <bfd_reloc_outofrange>: Add
error messages for jumps to misaligned addresses.
gas/
* config/tc-mips.c (mips_force_relocation): Also retain branch
relocations against MIPS16 and microMIPS symbols.
(fix_bad_cross_mode_jump_p): New function.
(fix_bad_same_mode_jalx_p): Likewise.
(fix_bad_misaligned_jump_p): Likewise.
(fix_bad_cross_mode_branch_p): Likewise.
(fix_bad_misaligned_branch_p): Likewise.
(fix_validate_branch): Likewise.
(md_apply_fix) <BFD_RELOC_MIPS_JMP, BFD_RELOC_MIPS16_JMP>
<BFD_RELOC_MICROMIPS_JMP>: Separate from BFD_RELOC_MIPS_SHIFT5,
etc. Verify the ISA mode and alignment of the jump target.
<BFD_RELOC_MIPS_21_PCREL_S2>: Replace the inline alignment check
with a call to `fix_validate_branch'.
<BFD_RELOC_MIPS_26_PCREL_S2>: Likewise.
<BFD_RELOC_16_PCREL_S2>: Likewise.
<BFD_RELOC_MICROMIPS_7_PCREL_S1, BFD_RELOC_MICROMIPS_10_PCREL_S1>
<BFD_RELOC_MICROMIPS_16_PCREL_S1>: Retain the original addend.
Verify the ISA mode and alignment of the branch target.
(md_convert_frag): Verify the ISA mode and alignment of resolved
MIPS16 branch targets.
* testsuite/gas/mips/branch-misc-1.s: Annotate non-instruction
branch targets with `.insn'.
* testsuite/gas/mips/branch-misc-5.s: Likewise.
* testsuite/gas/mips/micromips@branch-misc-5-64.d: Update
accordingly.
* testsuite/gas/mips/micromips@branch-misc-5pic-64.d: Likewise.
* testsuite/gas/mips/micromips-branch-relax.s: Annotate
non-instruction branch target with `.insn'.
* testsuite/gas/mips/micromips.s: Replace microMIPS JALX targets
with external symbols.
* testsuite/gas/mips/micromips-insn32.d: Update accordingly.
* testsuite/gas/mips/micromips-noinsn32.d: Likewise.
* testsuite/gas/mips/micromips-trap.d: Likewise.
* testsuite/gas/mips/micromips.d: Likewise.
* testsuite/gas/mips/mips16.s: Annotate non-instruction branch
targets with `.insn'.
* testsuite/gas/mips/mips16.d: Update accordingly.
* testsuite/gas/mips/mips16-64.d: Likewise.
* testsuite/gas/mips/mips16-dwarf2.s: Annotate non-instruction
branch target with `.insn'.
* testsuite/gas/mips/relax-swap3.s: Likewise.
* testsuite/gas/mips/branch-local-2.l: New list test.
* testsuite/gas/mips/branch-local-3.l: New list test.
* testsuite/gas/mips/branch-local-n32-2.l: New list test.
* testsuite/gas/mips/branch-local-n32-3.l: New list test.
* testsuite/gas/mips/branch-local-n64-2.l: New list test.
* testsuite/gas/mips/branch-local-n64-3.l: New list test.
* testsuite/gas/mips/unaligned-jump-1.l: New list test.
* testsuite/gas/mips/unaligned-jump-2.l: New list test.
* testsuite/gas/mips/unaligned-jump-3.d: New test.
* testsuite/gas/mips/unaligned-jump-mips16-1.l: New list test.
* testsuite/gas/mips/unaligned-jump-mips16-2.l: New list test.
* testsuite/gas/mips/unaligned-jump-mips16-3.d: New test.
* testsuite/gas/mips/unaligned-jump-micromips-1.l: New list
test.
* testsuite/gas/mips/unaligned-jump-micromips-2.l: New list
test.
* testsuite/gas/mips/unaligned-jump-micromips-3.d: New test.
* testsuite/gas/mips/unaligned-branch-1.l: New list test.
* testsuite/gas/mips/unaligned-branch-2.l: New list test.
* testsuite/gas/mips/unaligned-branch-3.d: New test.
* testsuite/gas/mips/unaligned-branch-r6-1.l: New list test.
* testsuite/gas/mips/unaligned-branch-r6-2.l: New list test.
* testsuite/gas/mips/unaligned-branch-r6-3.l: New list test.
* testsuite/gas/mips/unaligned-branch-r6-4.l: New list test.
* testsuite/gas/mips/unaligned-branch-r6-5.d: New test.
* testsuite/gas/mips/unaligned-branch-r6-6.d: New test.
* testsuite/gas/mips/unaligned-branch-mips16-1.l: New list test.
* testsuite/gas/mips/unaligned-branch-mips16-2.l: New list test.
* testsuite/gas/mips/unaligned-branch-mips16-3.d: New test.
* testsuite/gas/mips/unaligned-branch-micromips-1.l: New list
test.
* testsuite/gas/mips/unaligned-branch-micromips-2.l: New list
test.
* testsuite/gas/mips/unaligned-branch-micromips-3.d: New test.
* testsuite/gas/mips/branch-local-2.s: New test source.
* testsuite/gas/mips/branch-local-3.s: New test source.
* testsuite/gas/mips/branch-local-n32-2.s: New test source.
* testsuite/gas/mips/branch-local-n32-3.s: New test source.
* testsuite/gas/mips/branch-local-n64-2.s: New test source.
* testsuite/gas/mips/branch-local-n64-3.s: New test source.
* testsuite/gas/mips/unaligned-jump-1.s: New test source.
* testsuite/gas/mips/unaligned-jump-2.s: New test source.
* testsuite/gas/mips/unaligned-jump-mips16-1.s: New test source.
* testsuite/gas/mips/unaligned-jump-mips16-2.s: New test source.
* testsuite/gas/mips/unaligned-jump-micromips-1.s: New test
source.
* testsuite/gas/mips/unaligned-jump-micromips-2.s: New test
source.
* testsuite/gas/mips/unaligned-branch-1.s: New test source.
* testsuite/gas/mips/unaligned-branch-2.s: New test source.
* testsuite/gas/mips/unaligned-branch-r6-1.s: New test source.
* testsuite/gas/mips/unaligned-branch-r6-2.s: New test source.
* testsuite/gas/mips/unaligned-branch-r6-3.s: New test source.
* testsuite/gas/mips/unaligned-branch-r6-4.s: New test source.
* testsuite/gas/mips/unaligned-branch-mips16-1.s: New test
source.
* testsuite/gas/mips/unaligned-branch-mips16-2.s: New test
source.
* testsuite/gas/mips/unaligned-branch-micromips-1.s: New test
source.
* testsuite/gas/mips/unaligned-branch-micromips-2.s: New test
source.
* testsuite/gas/mips/mips.exp: Run the new tests.
ld/
* testsuite/ld-mips-elf/unaligned-jalx-1.d: Update error message
expected.
* testsuite/ld-mips-elf/unaligned-jalx-addend-1.d: Likewise.
* testsuite/ld-mips-elf/unaligned-jalx-addend-mips16-1.d:
Likewise.
* testsuite/ld-mips-elf/unaligned-jalx-addend-micromips-1.d:
Likewise.
* testsuite/ld-mips-elf/unaligned-jalx-mips16-1.d: Likewise.
* testsuite/ld-mips-elf/unaligned-jalx-micromips-1.d: Likewise.
* testsuite/ld-mips-elf/undefweak-overflow.s: Add jumps,
microMIPS BAL and MIPS16 instructions.
* testsuite/ld-mips-elf/undefweak-overflow.d: Update
accordingly.
* testsuite/ld-mips-elf/unaligned-branch-2.d: New test.
* testsuite/ld-mips-elf/unaligned-branch-r6-1.d: New test.
* testsuite/ld-mips-elf/unaligned-branch-r6-2.d: New test.
* testsuite/ld-mips-elf/unaligned-branch-mips16.d: New test.
* testsuite/ld-mips-elf/unaligned-branch-micromips.d: New test.
* testsuite/ld-mips-elf/unaligned-jump-mips16.d: New test.
* testsuite/ld-mips-elf/unaligned-jump-micromips.d: New test.
* testsuite/ld-mips-elf/unaligned-jump.d: New test.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.
Don't convert PC-relative REL relocations against absolute symbols to
section-relative references and retain the original symbol reference
instead. Offsets into the absolute section may overflow the limited
range of their in-place addend field, causing an assembly error, e.g.:
$ cat test.s
.text
.globl foo
.ent foo
foo:
b bar
.end foo
.set bar, 0x12345678
$ as -EB -32 -o test.o test.s
test.s: Assembler messages:
test.s:3: Error: relocation overflow
$
With the original reference retained the source can now be assembled and
linked successfully:
$ as -EB -32 -o test.o test.s
$ objdump -dr test.o
test.o: file format elf32-tradbigmips
Disassembly of section .text:
00000000 <foo>:
0: 1000ffff b 0 <foo>
0: R_MIPS_PC16 bar
4: 00000000 nop
...
$ ld -melf32btsmip -Ttext 0x12340000 -e foo -o test test.o
$ objdump -dr test
test: file format elf32-tradbigmips
Disassembly of section .text:
12340000 <foo>:
12340000: 1000159d b 12345678 <bar>
12340004: 00000000 nop
...
$
For simplicity always retain the original symbol reference, even if it
would indeed fit.
Making TC_FORCE_RELOCATION_ABS separate from TC_FORCE_RELOCATION causes
R_MICROMIPS_PC7_S1, R_MICROMIPS_PC10_S1 and R_MICROMIPS_PC16_S1 branch
relocations against absolute symbols to be converted on RELA targets to
section-relative references. This is an intended effect of this change.
Absolute symbols carry no ISA annotation in their `st_other' field and
their value is not going to change with linker relaxation, so it is safe
to discard the original reference and keep the calculated final symbol
value only in the relocation's addend.
Similarly R6 R_MIPS_PCHI16 and R_MIPS_PCLO16 relocations referring
absolute symbols can be safely converted even on REL targets, as there
the in-place addend of these relocations covers the entire 32-bit
address space so it can hold the calculated final symbol value, and
likewise the value referred won't be affected by any linker relaxation.
Add a set of suitable test cases and enable REL linker tests which now
work and were previously used as dump patterns for RELA tests only.
gas/
* config/tc-mips.h (TC_FORCE_RELOCATION_ABS): New macro.
(mips_force_relocation_abs): New prototype.
* config/tc-mips.c (mips_force_relocation_abs): New function.
* testsuite/gas/mips/branch-absolute.d: Adjust dump patterns.
* testsuite/gas/mips/mips16-branch-absolute.d: Likewise.
* testsuite/gas/mips/micromips-branch-absolute-n32.d: Likewise.
* testsuite/gas/mips/micromips-branch-absolute-n64.d: Likewise.
* testsuite/gas/mips/micromips-branch-absolute-addend-n32.d:
Likewise.
* testsuite/gas/mips/micromips-branch-absolute-addend-n64.d:
Likewise.
* testsuite/gas/mips/branch-absolute-addend.d: New test.
* testsuite/gas/mips/mips16-branch-absolute-addend.d: New test.
* testsuite/gas/mips/micromips-branch-absolute-addend.d: New
test.
* testsuite/gas/mips/mips.exp: Run the new tests.
ld/
* testsuite/ld-mips-elf/mips-elf.exp: Run
`branch-absolute-addend', `mips16-branch-absolute',
`mips16-branch-absolute-addend' and
`micromips-branch-absolute-addend'.
Correct a problem with the ISA bit being stripped from the addend of
compressed branch relocations, affecting RELA targets. It has been
there since microMIPS support has been added, with:
commit df58fc944d
Author: Richard Sandiford <rdsandiford@googlemail.com>
Date: Sun Jul 24 14:20:15 2011 +0000
<https://sourceware.org/ml/binutils/2011-07/msg00198.html>, ("MIPS:
microMIPS ASE support") and R_MICROMIPS_PC7_S1, R_MICROMIPS_PC10_S1 and
R_MICROMIPS_PC16_S1 relocations originally affected, and the
R_MIPS16_PC16_S1 relocation recently added with commit c9775dde32
("MIPS16: Add R_MIPS16_PC16_S1 branch relocation support") actually
triggering a linker error, due to its heightened processing strictness
level:
$ cat test.s
.text
.set mips16
foo:
b bar
.set bar, 0x1235
.align 4, 0
$ as -EB -n32 -o test.o test.s
$ objdump -dr test.o
test.o: file format elf32-ntradbigmips
Disassembly of section .text:
00000000 <foo>:
0: f000 1000 b 4 <foo+0x4>
0: R_MIPS16_PC16_S1 *ABS*+0x1230
...
$ ld -melf32btsmipn32 -Ttext 0 -e 0 -o test test.o
test.o: In function `foo':
(.text+0x0): Branch to a non-instruction-aligned address
$
This is because the ISA bit of the branch target does not match the ISA
bit of the referring branch, hardwired to 1 of course.
Retain the ISA bit then, so that the linker knows this is really MIPS16
code referred:
$ objdump -dr fixed.o
fixed.o: file format elf32-ntradbigmips
Disassembly of section .text:
00000000 <foo>:
0: f000 1000 b 4 <foo+0x4>
0: R_MIPS16_PC16_S1 *ABS*+0x1231
...
$ ld -melf32btsmipn32 -Ttext 0 -e 0 -o fixed fixed.o
$
Add a set of MIPS16 tests to cover the relevant cases, excluding linker
tests though which would overflow the in-place addend on REL targets and
use them as dump patterns for RELA targets only.
gas/
* config/tc-mips.c (md_apply_fix) <BFD_RELOC_MIPS16_16_PCREL_S1>
<BFD_RELOC_MICROMIPS_7_PCREL_S1, BFD_RELOC_MICROMIPS_10_PCREL_S1>
<BFD_RELOC_MICROMIPS_16_PCREL_S1>: Keep the ISA bit in the
addend calculated.
* testsuite/gas/mips/mips16-branch-absolute.s: Set the ISA bit
in `bar', export `foo'.
* testsuite/gas/mips/mips16-branch-absolute.d: Adjust
accordingly.
* testsuite/gas/mips/mips16-branch-absolute-n32.d: Likewise.
* testsuite/gas/mips/mips16-branch-absolute-n64.d: Likewise.
* testsuite/gas/mips/mips16-branch-absolute-addend-n32.d:
Likewise.
* testsuite/gas/mips/mips16-branch-absolute-addend-n64.d:
Likewise.
ld/
* testsuite/ld-mips-elf/mips16-branch-absolute.d: New test.
* testsuite/ld-mips-elf/mips16-branch-absolute-n32.d: New test.
* testsuite/ld-mips-elf/mips16-branch-absolute-n64.d: New test.
* testsuite/ld-mips-elf/mips16-branch-absolute-addend.d: New
test.
* testsuite/ld-mips-elf/mips16-branch-absolute-addend-n32.d: New
test.
* testsuite/ld-mips-elf/mips16-branch-absolute-addend-n64.d: New
test.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests, except
from `mips16-branch-absolute' and
`mips16-branch-absolute-addend', referred indirectly only.
Fix a generic BFD issue with relocations against absolute symbols, which
are installed without using any individual relocation handler provided
by the backend. This causes any absolute section's addend to be lost on
REL targets such as o32 MIPS, and also relocation-specific calculation
adjustments are not made.
As an example assembling this program:
$ cat test.s
.text
foo:
b bar
b baz
.set bar, 0x1234
$ as -EB -32 -o test-o32.o test.s
$ as -EB -n32 -o test-n32.o test.s
produces this binary code:
$ objdump -dr test-o32.o test-n32.o
test-o32.o: file format elf32-tradbigmips
Disassembly of section .text:
00000000 <foo>:
0: 10000000 b 4 <foo+0x4>
0: R_MIPS_PC16 *ABS*
4: 00000000 nop
8: 1000ffff b 8 <foo+0x8>
8: R_MIPS_PC16 baz
c: 00000000 nop
test-n32.o: file format elf32-ntradbigmips
Disassembly of section .text:
00000000 <foo>:
0: 10000000 b 4 <foo+0x4>
0: R_MIPS_PC16 *ABS*+0x1230
4: 00000000 nop
8: 10000000 b c <foo+0xc>
8: R_MIPS_PC16 baz-0x4
c: 00000000 nop
$
where it is clearly visible in `test-o32.o', which uses REL relocations,
that the absolute section's addend equivalent to the value of `bar' -- a
reference to which cannot be fully resolved at the assembly time,
because the reference is PC-relative -- has been lost, as has been the
relocation-specific adjustment of -4, required to take into account the
PC+4-relative calculation made by hardware with branches and seen in the
external symbol reference to `baz' as the `ffff' addend encoded in the
instruction word. In `test-n32.o', which uses RELA relocations, the
absolute section's addend has been correctly retained.
Give precedence then in `bfd_perform_relocation' and
`bfd_install_relocation' to any individual relocation handler the
backend selected may have provided, while still resorting to the generic
calculation otherwise. This retains the semantics which we've had since
forever or before the beginning of our repository history, and is at the
very least compatible with `bfd_elf_generic_reloc' being used as the
handler.
Retain the `bfd_is_und_section' check unchanged at the beginning of
`bfd_perform_relocation' since this does not affect the semantics of the
function. The check returns the same `bfd_reloc_undefined' code the
check for a null `howto' does, so swapping the two does not matter.
Also the check is is mutually exclusive with the `bfd_is_abs_section'
check, since a section cannot be absolute and undefined both at once, so
swapping the two does not matter either.
With this change applied the program quoted above now has the in-place
addend correctly calculated and installed in the field being relocated:
$ objdump -dr fixed-o32.o
fixed-o32.o: file format elf32-tradbigmips
Disassembly of section .text:
00000000 <foo>:
0: 1000048c b 1234 <bar>
0: R_MIPS_PC16 *ABS*
4: 00000000 nop
8: 1000ffff b 8 <foo+0x8>
8: R_MIPS_PC16 baz
c: 00000000 nop
$
Add a set of MIPS tests to cover the relevant cases, including absolute
symbols with addends, and verifying that PC-relative relocations against
symbols concerned resolve to the same value in the final link regardless
of whether the REL or the RELA relocation form is used. Exclude linker
tests though which would overflow the in-place addend on REL targets and
use them as dump patterns for RELA targets only.
bfd/
* reloc.c (bfd_perform_relocation): Try the `howto' handler
first with relocations against absolute symbols.
(bfd_install_relocation): Likewise.
gas/
* testsuite/gas/mips/mips16-branch-absolute.d: Update patterns.
* testsuite/gas/mips/branch-absolute.d: New test.
* testsuite/gas/mips/branch-absolute-n32.d: New test.
* testsuite/gas/mips/branch-absolute-n64.d: New test.
* testsuite/gas/mips/branch-absolute-addend-n32.d: New test.
* testsuite/gas/mips/branch-absolute-addend-n64.d: New test.
* testsuite/gas/mips/mips16-branch-absolute-n32.d: New test.
* testsuite/gas/mips/mips16-branch-absolute-n64.d: New test.
* testsuite/gas/mips/mips16-branch-absolute-addend-n32.d: New
test.
* testsuite/gas/mips/mips16-branch-absolute-addend-n64.d: New
test.
* testsuite/gas/mips/micromips-branch-absolute.d: New test.
* testsuite/gas/mips/micromips-branch-absolute-n32.d: New test.
* testsuite/gas/mips/micromips-branch-absolute-n64.d: New test.
* testsuite/gas/mips/micromips-branch-absolute-addend-n32.d: New
test.
* testsuite/gas/mips/micromips-branch-absolute-addend-n64.d: New
test.
* testsuite/gas/mips/branch-absolute.s: New test source.
* testsuite/gas/mips/branch-absolute-addend.s: New test source.
* testsuite/gas/mips/mips16-branch-absolute-addend.s: New test
source.
* testsuite/gas/mips/micromips-branch-absolute.s: New test
source.
* testsuite/gas/mips/micromips-branch-absolute-addend.s: New
test source.
* testsuite/gas/mips/mips.exp: Run the new tests.
ld/
* testsuite/ld-mips-elf/branch-absolute.d: New test.
* testsuite/ld-mips-elf/branch-absolute-n32.d: New test.
* testsuite/ld-mips-elf/branch-absolute-n64.d: New test.
* testsuite/ld-mips-elf/branch-absolute-addend.d: New test.
* testsuite/ld-mips-elf/branch-absolute-addend-n32.d: New test.
* testsuite/ld-mips-elf/branch-absolute-addend-n64.d: New test.
* testsuite/ld-mips-elf/micromips-branch-absolute.d: New test.
* testsuite/ld-mips-elf/micromips-branch-absolute-n32.d: New
test.
* testsuite/ld-mips-elf/micromips-branch-absolute-n64.d: New
test.
* testsuite/ld-mips-elf/micromips-branch-absolute-addend.d: New
test.
* testsuite/ld-mips-elf/micromips-branch-absolute-addend-n32.d:
New test.
* testsuite/ld-mips-elf/micromips-branch-absolute-addend-n64.d:
New test.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests, except
from `branch-absolute-addend' and
`micromips-branch-absolute-addend', referred indirectly only.
Fix internal errors like:
ld: BFD (GNU Binutils) 2.26.51.20160526 internal error, aborting at .../bfd/elfxx-mips.c:10278 in _bfd_mips_elf_relocate_section
ld: Please report this bug.
triggered by the `bfd_reloc_outofrange' condition on branch relocations.
bfd/
* elfxx-mips.c (b_reloc_p): New function.
(_bfd_mips_elf_relocate_section) <bfd_reloc_outofrange>: Handle
branch relocations.
ld/
* testsuite/ld-mips-elf/unaligned-branch.d: New test.
* testsuite/ld-mips-elf/unaligned-branch.s: New test source.
* testsuite/ld-mips-elf/unaligned-text.s: New test source.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new test.
The original MIPS SVR4 psABI defines the calculation for the R_MIPS_26
relocation in a complex way, as follows[1]:
Name Value Field Symbol Calculation
R_MIPS_26 4 T-targ26 local (((A << 2) | \
(P & 0xf0000000)) + S) >> 2
4 T-targ26 external (sign-extend(A << 2) + S) >> 2
This is further clarified, by correcting typos (already applied in the
excerpt above) in the 64-bit psABI extension[2]. A note is included in
both documents to specify that for the purpose of relocation processing
a local symbol is one with binding STB_LOCAL and type STT_SECTION, and
otherwise, a symbol is external.
We have both calculations implemented for the R_MIPS_26 relocation, and
by extension also for the R_MIPS16_26 and R_MICROMIPS_26_S1 relocations,
from now on collectively called jump relocations. However our code uses
a different condition to tell local and external symbols apart, that is
it only checks for the STB_LOCAL binding and ignores the symbol type,
however for REL relocations only. The external calculation is used for
all RELA jump relocations.
In reality the difference matters for jump relocations referring local
MIPS16 and, as from recent commit 44d3da2338 ("MIPS/GAS: Treat local
jump relocs the same no matter if REL or RELA"), also local microMIPS
symbols. Such relocations are not converted to refer to corresponding
section symbols instead and retain the original local symbol reference.
It can be inferred from the relocation calculation definitions that the
addend is effectively unsigned for the local case and explicitly signed
for the external case. With the REL relocation format it makes sense
given the limited range provided for by the field being relocated: the
use of an unsigned addend expands the range by one bit for the local
case, because a negative offset from a section symbol makes no sense,
and any usable negative offset from the original local symbol will have
worked out positive if converted to a section-relative reference. In
the external case a signed addend gives more flexibility as offsets both
negative and positive can be used with a symbol. Any such offsets will
typically have a small value.
The inclusion of the (P & 0xf0000000) component, ORed in the calculation
in the local case, seems questionable as bits 31:28 are not included in
the relocatable field and are masked out as the relocation is applied.
Their value is therefore irrelevant for output processing, the relocated
field ends up the same regardless of their value. They could be used
for overflow detection, however this is precluded by adding them to bits
31:28 of the symbol referred, as the sum will not correspond to the
value calculated by the processor at run time whenever bits 31:28 of the
symbol referred are not all zeros, even though it is valid as long they
are the same as bits 31:28 of P.
We deal with this problem by ignoring any overflow resulting from the
local calculation. This however makes us miss genuine overflow cases,
where 31:28 of the symbol referred are different from bits 31:28 of P,
and non-functional code is produced.
Given the situation, for the purpose of overflow detection we can change
our code to follow the original psABI and only treat the in-place addend
as unsigned in the section symbol case, permitting jumps to offsets
128MiB and above into section. Sections so large may be uncommon, but
still a reasonable use case. On the other hand such large offsets from
regular local symbols are not expected and it makes sense to support
(possibly small) negative offsets instead, also in consistency with what
we do for global symbols.
Drop the (P & 0xf0000000) component then, treat the addend as signed
with local non-section symbols and also detect an overflow in the result
of such calculation with local symbols. NB it does not affect the value
computed for the relocatable field, it only affects overflow detection.
References:
[1] "SYSTEM V APPLICATION BINARY INTERFACE, MIPS RISC Processor
Supplement, 3rd Edition", Figure 4-11: "Relocation Types", p. 4-19
<http://www.linux-mips.org/pub/linux/mips/doc/ABI/mipsabi.pdf>
[2] "64-bit ELF Object File Specification, Draft Version 2.5", Table 32
"Relocation Types", p. 45
<http://techpubs.sgi.com/library/manuals/4000/007-4658-001/pdf/007-4658-001.pdf>
bfd/
* elfxx-mips.c (mips_elf_calculate_relocation): <R_MIPS16_26>
<R_MIPS_26, R_MICROMIPS_26_S1>: Drop the region bits of the
reloc location from calculation, treat the addend as signed with
local non-section symbols and enable overflow detection.
ld/
* testsuite/ld-mips-elf/jal-global-overflow-0.d: New test.
* testsuite/ld-mips-elf/jal-global-overflow-1.d: New test.
* testsuite/ld-mips-elf/jal-local-overflow-0.d: New test.
* testsuite/ld-mips-elf/jal-local-overflow-1.d: New test.
* testsuite/ld-mips-elf/jal-global-overflow.s: New test source.
* testsuite/ld-mips-elf/jal-local-overflow.s: New test source.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.
On RELA targets the addend can affect JALX target's alignment, so only
verify it once the whole relocation calculation has completed.
bfd/
* elfxx-mips.c (mips_elf_calculate_relocation) <R_MIPS16_26>
<R_MIPS_26, R_MICROMIPS_26_S1>: Include the addend in JALX's
target alignment verification.
ld/
* testsuite/ld-mips-elf/unaligned-jalx-addend-0.d: New test.
* testsuite/ld-mips-elf/unaligned-jalx-addend-1.d: New test.
* testsuite/ld-mips-elf/unaligned-jalx-addend-mips16-0.d: New
test.
* testsuite/ld-mips-elf/unaligned-jalx-addend-mips16-1.d: New
test.
* testsuite/ld-mips-elf/unaligned-jalx-addend-micromips-0.d: New
test.
* testsuite/ld-mips-elf/unaligned-jalx-addend-micromips-1.d: New
test.
* testsuite/ld-mips-elf/unaligned-jalx-addend-0.s: New test
source.
* testsuite/ld-mips-elf/unaligned-jalx-addend-1.s: New test
source.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.
Symbol table entries for section symbols are different between IRIX and
traditional MIPS ELF targets in that IRIX entries have their `st_name'
member pointing at the section's name in the string table section, while
traditional entries have 0 there and the section header string table has
to be referred via the relevant section header's `shn_name' member
instead.
This is chosen with the `elf_backend_name_local_section_symbols' backend
and can be observed with `readelf -s' output for an IRIX object:
Symbol table '.symtab' contains 12 entries:
Num: Value Size Type Bind Vis Ndx Name
0: 00000000 0 NOTYPE LOCAL DEFAULT UND
1: 00000000 0 SECTION LOCAL DEFAULT 1 .text
2: 00000000 0 SECTION LOCAL DEFAULT 3 .data
3: 00000000 0 SECTION LOCAL DEFAULT 4 .bss
4: 00000000 0 SECTION LOCAL DEFAULT 5 .reginfo
5: 00000000 0 SECTION LOCAL DEFAULT 6 .MIPS.abiflags
6: 00000000 0 SECTION LOCAL DEFAULT 7 .pdr
7: 00000000 0 SECTION LOCAL DEFAULT 9 .gnu.attributes
8: 00002000 16 FUNC GLOBAL DEFAULT 1 foo
9: 00004008 0 FUNC LOCAL DEFAULT 1 abar
10: 00002008 0 FUNC LOCAL DEFAULT 1 afoo
11: 00004000 16 FUNC GLOBAL DEFAULT 1 bar
and a corresponding traditional object:
Symbol table '.symtab' contains 12 entries:
Num: Value Size Type Bind Vis Ndx Name
0: 00000000 0 NOTYPE LOCAL DEFAULT UND
1: 00000000 0 SECTION LOCAL DEFAULT 1
2: 00000000 0 SECTION LOCAL DEFAULT 3
3: 00000000 0 SECTION LOCAL DEFAULT 4
4: 00004008 0 FUNC LOCAL DEFAULT 1 abar
5: 00002008 0 FUNC LOCAL DEFAULT 1 afoo
6: 00000000 0 SECTION LOCAL DEFAULT 5
7: 00000000 0 SECTION LOCAL DEFAULT 6
8: 00000000 0 SECTION LOCAL DEFAULT 7
9: 00000000 0 SECTION LOCAL DEFAULT 9
10: 00002000 16 FUNC GLOBAL DEFAULT 1 foo
11: 00004000 16 FUNC GLOBAL DEFAULT 1 bar
respectively. Consequently the right way to retrieve a section symbol's
name has to be chosen in `mips_elf_calculate_relocation' for the purpose
of error reporting.
Originally we produced symbol tables in the traditional object format
only and we handled it correctly until it was lost in a rewrite with:
commit 7403cb6305
Author: Mark Mitchell <mark@codesourcery.com>
Date: Wed Jun 30 20:13:43 1999 +0000
probably because of the extra pointer indirection added which made the
same expression have a different meaning.
With the addition of IRIX symbol table format with:
commit 174fd7f955
Author: Richard Sandiford <rdsandiford@googlemail.com>
Date: Mon Feb 9 08:04:00 2004 +0000
the bug has been partially covered and now when a relocation error is
triggered with an IRIX object the offending section symbol is correctly
reported:
tmpdir/dump0.o: In function `foo':
(.text+0x2000): relocation truncated to fit: R_MIPS_26 against `.text'
tmpdir/dump0.o: In function `bar':
(.text+0x4000): relocation truncated to fit: R_MIPS_26 against `.text'
because `bfd_elf_string_from_elf_section' retrieves the name from the
string table section. With a traditional object however the function
returns an empty string and consequently `no symbol' is printed instead:
tmpdir/dump0.o: In function `foo':
(.text+0x2000): relocation truncated to fit: R_MIPS_26 against `no symbol'
tmpdir/dump0.o: In function `bar':
(.text+0x4000): relocation truncated to fit: R_MIPS_26 against `no symbol'
Restore the original semantics so that the section name is always
correctly retrieved.
bfd/
* elfxx-mips.c (mips_elf_calculate_relocation): Also use the
section name if `bfd_elf_string_from_elf_section' returns an
empty string.
ld/
* testsuite/ld-mips-elf/reloc-local-overflow.d: New test.
* testsuite/ld-mips-elf/reloc-local-overflow.s: Source for the
new test.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new test.
Upon a `bfd_reloc_outofrange' error continue processing so that any
further issues are also reported, similarly to how `bfd_reloc_overflow'
is handled. Adjust message formatting accordingly, using `%X' to abort
processing at conclusion.
Reduce the number of test cases by grouping relocations the handling of
which can now be verified together with a single source and dump.
bfd/
* elfxx-mips.c (_bfd_mips_elf_relocate_section)
<bfd_reloc_outofrange>: Use the `%X%H' rather than `%C' format
for message. Continue processing rather than returning failure.
ld/
* testsuite/ld-mips-elf/unaligned-jalx-0.d: Fold
`unaligned-jalx-2' here.
* testsuite/ld-mips-elf/unaligned-jalx-mips16-0.d: Fold
`unaligned-jalx-mips16-2' here.
* testsuite/ld-mips-elf/unaligned-jalx-micromips-0.d: Fold
`unaligned-jalx-micromips-2' here.
* testsuite/ld-mips-elf/unaligned-jalx-0.s: Update accordingly.
* testsuite/ld-mips-elf/unaligned-jalx-1.d: Update error
message.
* testsuite/ld-mips-elf/unaligned-jalx-mips16-1.d: Likewise.
* testsuite/ld-mips-elf/unaligned-jalx-micromips-1.d: Likewise.
* testsuite/ld-mips-elf/unaligned-jalx-2.d: Remove test.
* testsuite/ld-mips-elf/unaligned-jalx-mips16-2.d: Remove test.
* testsuite/ld-mips-elf/unaligned-jalx-micromips-2.d: Remove
test.
* testsuite/ld-mips-elf/unaligned-jalx-2.s: Remove test source.
* testsuite/ld-mips-elf/unaligned-lwpc-0.d: Fold
`unaligned-lwpc-3' here.
* testsuite/ld-mips-elf/unaligned-lwpc-0.s: Update accordingly.
* testsuite/ld-mips-elf/unaligned-lwpc-1.d: Fold
`unaligned-lwpc-2' here.
* testsuite/ld-mips-elf/unaligned-lwpc-1.s: Update accordingly.
* testsuite/ld-mips-elf/unaligned-lwpc-2.d: Remove test.
* testsuite/ld-mips-elf/unaligned-lwpc-2.s: Remove test source.
* testsuite/ld-mips-elf/unaligned-lwpc-3.d: Remove test.
* testsuite/ld-mips-elf/unaligned-lwpc-3.s: Remove test source.
* testsuite/ld-mips-elf/unaligned-ldpc-0.d: Fold
`unaligned-ldpc-4' here.
* testsuite/ld-mips-elf/unaligned-ldpc-0.s: Update accordingly.
* testsuite/ld-mips-elf/unaligned-ldpc-1.d: Update error
message. Fold `unaligned-ldpc-2' and `unaligned-ldpc-3' here.
* testsuite/ld-mips-elf/unaligned-ldpc-1.s: Update accordingly.
* testsuite/ld-mips-elf/unaligned-ldpc-2.d: Remove test.
* testsuite/ld-mips-elf/unaligned-ldpc-2.s: Remove test source.
* testsuite/ld-mips-elf/unaligned-ldpc-3.d: Remove test.
* testsuite/ld-mips-elf/unaligned-ldpc-3.s: Remove test source.
* testsuite/ld-mips-elf/unaligned-ldpc-4.d: Remove test.
* testsuite/ld-mips-elf/unaligned-ldpc-4.s: Remove test source.
* testsuite/ld-mips-elf/mips-elf.exp: Delete removed tests.
A `bfd_reloc_outofrange' condition from `mips_elf_calculate_relocation'
currently triggers the warning callback, which in the case of LD prints
messages like:
foo.o: In function `foo':
(.text+0x0): warning: JALX to a non-word-aligned address
or:
foo.o: In function `foo':
(.text+0x0): warning: PC-relative load from unaligned address
and nothing else, which suggests this is a benign condition and link has
otherwise successfully run to completion. This is however not the case,
the link terminates right away with no further messages and no output
produced.
Use the general error or warning info callback then, preserving the
message format. Also set a BFD error condition so that a failure is
unambiguously reported. Complement the change with a set of suitable
test suite additions.
bfd/
* elfxx-mips.c (_bfd_mips_elf_relocate_section)
<bfd_reloc_outofrange>: Call `->einfo' rather than `->warning'.
Call `bfd_set_error'.
ld/
* testsuite/ld-mips-elf/unaligned-jalx-0.d: New test.
* testsuite/ld-mips-elf/unaligned-jalx-1.d: New test.
* testsuite/ld-mips-elf/unaligned-jalx-2.d: New test.
* testsuite/ld-mips-elf/unaligned-jalx-mips16-0.d: New test.
* testsuite/ld-mips-elf/unaligned-jalx-mips16-1.d: New test.
* testsuite/ld-mips-elf/unaligned-jalx-mips16-2.d: New test.
* testsuite/ld-mips-elf/unaligned-jalx-micromips-0.d: New test.
* testsuite/ld-mips-elf/unaligned-jalx-micromips-1.d: New test.
* testsuite/ld-mips-elf/unaligned-jalx-micromips-2.d: New test.
* testsuite/ld-mips-elf/unaligned-lwpc-0.d: New test.
* testsuite/ld-mips-elf/unaligned-lwpc-1.d: New test.
* testsuite/ld-mips-elf/unaligned-lwpc-2.d: New test.
* testsuite/ld-mips-elf/unaligned-lwpc-3.d: New test.
* testsuite/ld-mips-elf/unaligned-ldpc-0.d: New test.
* testsuite/ld-mips-elf/unaligned-ldpc-1.d: New test.
* testsuite/ld-mips-elf/unaligned-ldpc-2.d: New test.
* testsuite/ld-mips-elf/unaligned-ldpc-3.d: New test.
* testsuite/ld-mips-elf/unaligned-ldpc-4.d: New test.
* testsuite/ld-mips-elf/unaligned-jalx-0.s: New test source.
* testsuite/ld-mips-elf/unaligned-jalx-1.s: New test source.
* testsuite/ld-mips-elf/unaligned-jalx-2.s: New test source.
* testsuite/ld-mips-elf/unaligned-insn.s: New test source.
* testsuite/ld-mips-elf/unaligned-lwpc-0.s: New test source.
* testsuite/ld-mips-elf/unaligned-lwpc-1.s: New test source.
* testsuite/ld-mips-elf/unaligned-lwpc-2.s: New test source.
* testsuite/ld-mips-elf/unaligned-lwpc-3.s: New test source.
* testsuite/ld-mips-elf/unaligned-ldpc-0.s: New test source.
* testsuite/ld-mips-elf/unaligned-ldpc-1.s: New test source.
* testsuite/ld-mips-elf/unaligned-ldpc-2.s: New test source.
* testsuite/ld-mips-elf/unaligned-ldpc-3.s: New test source.
* testsuite/ld-mips-elf/unaligned-ldpc-4.s: New test source.
* testsuite/ld-mips-elf/unaligned-syms.s: New test source.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.
Do not convert jump relocs against local MIPS16 or microMIPS symbols to
refer to a section symbol instead even on RELA targets, as it makes it
impossible for the linker to make a JAL to JALX conversion based on ISA
symbol annotation, breaking regular and compressed MIPS interlinking.
gas/
* config/tc-mips.c (mips_fix_adjustable): Also return 0 for
jump relocations against MIPS16 or microMIPS symbols on RELA
targets.
* testsuite/gas/mips/jalx-local.d: New test.
* testsuite/gas/mips/jalx-local-n32.d: New test.
* testsuite/gas/mips/jalx-local-n64.d: New test.
* testsuite/gas/mips/jalx-local.s: New test source.
* testsuite/gas/mips/mips.exp: Run the new tests.
ld/
* testsuite/ld-mips-elf/jalx-local.d: New test.
* testsuite/ld-mips-elf/jalx-local-n32.d: New test.
* testsuite/ld-mips-elf/jalx-local-n64.d: New test.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.
The microMIPS JALX instruction shares the R_MICROMIPS_26_S1 relocation
with microMIPS J/JAL/JALS instructions, however unlike the latters its
encoded immediate argument is unusually shifted left by 2 rather than 1
in calculating the value used for the operation requested.
We already handle this exception in `mips_elf_calculate_relocation' in
LD, in a scenario where JALX is produced as a result of relaxing JAL for
the purpose of making a cross-mode jump. We also get it right in the
disassembler in `decode_micromips_operand'.
What we don't correctly do however is processing microMIPS JALX produced
by GAS from an assembly source, where a non-zero constant argument or a
symbol reference with a non-zero in-place addend has been used. In this
case the same calculation is made as for microMIPS J/JAL/JALS, causing
the wrong encoding to be produced by GAS on making an object file, and
then again by LD in the final link. The latter in particular causes the
calculation, where the addend fits in the relocatable field, to produce
different final addresses for the same source code depending on whether
REL or RELA relocations are used.
Correct these issues by special-casing microMIPS JALX in the places that
have been previously missed.
bfd/
* elfxx-mips.c (mips_elf_read_rel_addend): Adjust the addend for
microMIPS JALX.
gas/
* config/tc-mips.c (append_insn): Correct the encoding of a
constant argument for microMIPS JALX.
(tc_gen_reloc): Correct the encoding of an in-place addend for
microMIPS JALX.
* testsuite/gas/mips/jalx-addend.d: New test.
* testsuite/gas/mips/jalx-addend-n32.d: New test.
* testsuite/gas/mips/jalx-addend-n64.d: New test.
* testsuite/gas/mips/jalx-imm.d: New test.
* testsuite/gas/mips/jalx-imm-n32.d: New test.
* testsuite/gas/mips/jalx-imm-n64.d: New test.
* testsuite/gas/mips/jalx-addend.s: New test source.
* testsuite/gas/mips/jalx-imm.s: New test source.
* testsuite/gas/mips/mips.exp: Run the new tests.
ld/
* testsuite/ld-mips-elf/jalx-addend.d: New test.
* testsuite/ld-mips-elf/jalx-addend-n32.d: New test.
* testsuite/ld-mips-elf/jalx-addend-n64.d: New test.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.
Always turn hidden and internal symbols which have a dynamic index into
local ones. This is required by the the ELF gABI[1]:
"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."
"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."
The ELF linker usually respects this requirement, however in the case
where a dynamic symbol has been preallocated due to a reference of the
default export class aka visibility from the object being linked, and
then merged with a hidden or internal symbol definition from within the
same object, then the original export class is carried over to the
output dynamic symbol table, because while merging the generic ELF
linker only converts affected dynamic symbols to local when they are
defined or referenced by the object being linked and a dynamic object
involved in the link both at a time.
The dynamic symbol produced confuses then the dynamic loader at the run
time -- the hidden or internal export class is ignored and the symbol
follows preemption rules as with the default export class.
In the MIPS target it happens when `mips_elf_record_global_got_symbol'
creates a dynamic symbol when a call relocation is encountered.
Additionally if the undefined symbol referred by such a relocation does
specify the intended export class, then a local dynamic symbol is
created instead, which is harmless and allowed, but useless. Normally
no local dynamic symbols are created, except for a single dummy one at
the beginning.
Correct the problem by removing the extra check for a dynamic symbol
being defined or referenced by the object being linked and a dynamic
object involved in the link both at a time. The test cases included
cover the internal and hidden symbol cases, as well as a protected
symbol for a reference, the handling of which is unchanged by this fix.
Both cases described above are covered, that is where an internal or
hidden dynamic symbol is produced and where a local one is.
NB this change affects CRIS results where some symbols in the static
table produced in a final link are now converted from STV_HIDDEN to
STB_LOCAL. This happens whenever the `elf_backend_hide_symbol' handler
is called, so the affected symbols must have been chosen for entering
into the dynamic symbol table, except in these test cases no such symbol
table is produced. In fully linked binaries the static symbol table is
only used for debugging though, so such a change is fine.
References:
[1] "System V Application Binary Interface - DRAFT - 24 April 2001",
The Santa Cruz Operation, Inc., "Symbol Table",
<http://www.sco.com/developers/gabi/2001-04-24/ch4.symtab.html>
bfd/
PR ld/19908
* elflink.c (elf_link_add_object_symbols): Always turn hidden
and internal symbols which have a dynamic index into local
ones.
ld/
PR ld/19908
* testsuite/ld-cris/tls-e-20.d: Adjust for hidden symbol
handling fix.
* testsuite/ld-cris/tls-e-20a.d: Likewise.
* testsuite/ld-cris/tls-e-21.d: Likewise.
* testsuite/ld-cris/tls-e-23.d: Likewise.
* testsuite/ld-cris/tls-e-80.d: Likewise.
* testsuite/ld-cris/tls-gd-3h.d: Likewise.
* testsuite/ld-cris/tls-leie-19.d: Likewise.
* testsuite/ld-mips-elf/export-class-ref-lib.sd: New test.
* testsuite/ld-mips-elf/export-hidden-ref.sd: New test.
* testsuite/ld-mips-elf/export-internal-ref.sd: New test.
* testsuite/ld-mips-elf/export-protected-ref.sd: New test.
* testsuite/ld-mips-elf/export-class-ref-f0.s: New test source.
* testsuite/ld-mips-elf/export-class-ref-f1.s: New test source.
* testsuite/ld-mips-elf/export-class-ref-f2.s: New test source.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.
bfd/
* elfxx-mips.c (mips_elf_check_mips16_stubs): Set a stub's output
section to bfd_abs_section_ptr if the stub is discarded.
ld/testsuite/
* ld-mips-elf/mips16-fp-stub-1.s: New.
* ld-mips-elf/mips16-fp-stub-2.s: New.
* ld-mips-elf/mips16-fp-stub.d: New.
* ld-mips-elf/mips-elf.exp: Run new tests.
* ld-mips-elf/mips16-intermix.d: Update expected output.
https://sourceware.org/ml/binutils/2015-10/msg00137.html
In MIPS the relocation calculation only ignores the overflow checks for undefined
weak symbols on relocations associated with j/jal. This patch extends this to
the relocations used by the: b* instructions; pc/gp relative symbol offsets; and the
lwpc/ldpc MIPS r6 instructions.
bfd/
* elfxx-mips.c (mips_elf_calculate_relocation): Only check for overflow
on non-weak undefined symbols.
ld/testsuite/
* ld-mips-elf/mips-elf.exp: Add in undefined weak overflow tests for
o32, n32 and n64.
* ld-mips-elf/undefweak-overflow.s: New test.
* ld-mips-elf/undefweak-overflow.d: New test.
* ld-mips-elf/undefweak-overflow-n32.d: New test.
* ld-mips-elf/undefweak-overflow-n64.d: New test.
bfd/
* elfxx-mips.c (update_mips_abiflags_isa): Add E_MIPS_ARCH_32R6
and E_MIPS_ARCH_64R6 support.
ld/testsuite/
* ld-mips-elf/abiflags-strip10-ph.d: New file.
* ld-mips-elf/mips-eld.exp: Run the new test.
gas/
* config/tc-mips.c (mips_elf_final_processing): Add INSN_ISA32R6
and INSN_ISA64R6 support.
gas/testsuite/
* gas/mips/elf_arch_mips32r6.d: New file.
* gas/mips/elf_arch_mips64r6.d: New file.
* gas/mips/mips.exp: Run the new tests.
2013-11-27 Matthew Fortune <matthew.fortune@imgtec.com>
* binutils-all/objcopy.exp: Consider mips-mti-elf the same as
mips-sde-elf
* binutils-all/readelf.exp: Likewise
gas/testsuite/
2013-11-27 Matthew Fortune <matthew.fortune@imgtec.com>
* gas/mips/mips.exp: Consider mips-mti-elf the same as mips-sde-elf
ld/testsuite/
2013-11-27 Matthew Fortune <matthew.fortune@imgtec.com>
* ld-mips-elf/mips-elf.exp: Consider mips-mti-elf the same as
mips-sde-elf
* mips.h (EF_MIPS_NAN2008): New macro.
bfd/
* elfxx-mips.c (_bfd_mips_elf_merge_private_bfd_data): Handle
EF_MIPS_NAN2008.
(_bfd_mips_elf_print_private_bfd_data): Likewise.
binutils/
* readelf.c (get_machine_flags): Handle EF_MIPS_NAN2008.
gas/
* config/tc-mips.c (mips_flag_nan2008): New variable.
(options): Add OPTION_NAN enum value.
(md_longopts): Handle it.
(md_parse_option): Likewise.
(s_nan): New function.
(mips_elf_final_processing): Handle EF_MIPS_NAN2008.
(md_show_usage): Add -mnan.
* doc/as.texinfo (Overview): Add -mnan.
* doc/c-mips.texi (MIPS Opts): Document -mnan.
(MIPS NaN Encodings): New node. Document .nan directive.
(MIPS-Dependent): List the new node.
gas/testsuite/
* gas/mips/nan-2008-1.d: New test.
* gas/mips/nan-2008-2.d: New test.
* gas/mips/nan-2008-3.d: New test.
* gas/mips/nan-2008-4.d: New test.
* gas/mips/nan-legacy-1.d: New test.
* gas/mips/nan-legacy-2.d: New test.
* gas/mips/nan-legacy-3.d: New test.
* gas/mips/nan-legacy-4.d: New test.
* gas/mips/nan-legacy-5.d: New test.
* gas/mips/nan-error-1.l: New list test.
* gas/mips/nan-error-2.l: New list test.
* gas/mips/nan-2008-override.s: New test source.
* gas/mips/nan-2008.s: New test source.
* gas/mips/nan-legacy-override.s: New test source.
* gas/mips/nan-legacy.s: New test source.
* gas/mips/nan-error-1.s: New test source.
* gas/mips/nan-error-2.s: New test source.
* gas/mips/mips.exp: Run the new tests.
ld/testsuite/
* ld-mips-elf/nan-2008.d: New test.
* ld-mips-elf/nan-legacy.d: New test.
* ld-mips-elf/nan-mixed-1.d: New test.
* ld-mips-elf/nan-mixed-2.d: New test.
* ld-mips-elf/nan-2008.s: New test source.
* ld-mips-elf/nan-legacy.s: New test source.
* write.c (resolve_reloc_expr_symbols): On REL targets don't
convert relocs who have no relocatable field either. Rephrase
the conditional so that the PC-relative check is only applied
for REL targets.
gas/testsuite/
* gas/mips/jalr3.d: New test.
* gas/mips/jalr3-n32.d: New test.
* gas/mips/jalr3-n64.d: New test.
* gas/mips/jalr3.s: New test source.
* gas/mips/mips.exp: Run the new tests.
ld/testsuite/
* ld-mips-elf/jalr3.dd: New test.
* ld-mips-elf/jalr3.ld: New test linker script.
* ld-mips-elf/mips-elf.exp: Run the new test.
PR ld/15365
* layout.cc (Layout::finalize): Make __ehdr_start STV_HIDDEN.
ld/
PR ld/15365
* emultempl/elf32.em (gld${EMULATION_NAME}_before_allocation):
Restrict __ehdr_start's export class to no less than STV_HIDDEN.
ld/testsuite/
PR ld/15365
* ld-elf/ehdr_start.d: Expect __ehdr_start to be STB_LOCAL.
* ld-mips-elf/ehdr_start-1.nd: New test.
* ld-mips-elf/ehdr_start-2.nd: New test.
* ld-mips-elf/ehdr_start-1.ld: New test linker script.
* ld-mips-elf/ehdr_start-2.ld: New test linker script.
* ld-mips-elf/ehdr_start-new.s: New test source.
* ld-mips-elf/ehdr_start-o32.s: New test source.
* ld-mips-elf/mips-elf.exp: Run the new tests.
Maciej W. Rozycki