Commit 325ba6fb34 excluded degenerate zero length PT_LOAD segments,
but that only fixed part of the problem, which was that the load
segment limits were not calculated properly.
PR 22845
* elf.c (IS_TBSS): Define.
(_bfd_elf_map_sections_to_segments): Use IS_TBSS.
(assign_file_positions_for_non_load_sections): Revert last change.
Properly calculate load segment limits to compare against relro limits.
Fixes a failure triggered by -z separate-code. p_memsz is tested
rather than p_filesz for objcopy --only-keep-debug where p_filesz is
set to zero.
PR 22845
* elf.c (assign_file_positions_for_non_load_sections): Ignore
degenerate zero size PT_LOAD segments when finding one overlapping
the PT_GNU_RELRO segment.
bfd/
* elfnn-riscv.c (riscv_elf_relocate_section): Use bfd_reloc_dangerous
when pcrel_lo reloc has an addend. Use reloc_dangerous callback for
bfd_reloc_dangerous. Use einfo instead of warning callback for errors.
Add %X%P to error messages.
ld/
* testsuite/ld-riscv-elf/ld-riscv-elf.exp: Run pcrel-lo-addend test.
* testsuite/ld-riscv-elf/pcrel-lo-addend.d: New.
* testsuite/ld-riscv-elf/pcrel-lo-addend.s: New.
The fix for PR ld/22727 on SPARC passed TRUE as the 'create' argument
in the call to bfd_link_hash_lookup. It turns out this was a bad idea
because, if the symbol is created at this point, the link will abort
later in elf_link_output_extsym. This changes the TRUE into a FALSE
and puts an assertion on the result of the call, making it easier to
debug the issue; that's exactly in keeping with what Gold does.
bfd/
* elfxx-sparc.c (_bfd_sparc_elf_check_relocs) <R_SPARC_TLS_GD_CALL>:
Pass FALSE instead of TRUE as 'create' argument to bfd_link_hash_lookup
and assert that the result of the call is not NULL.
Since PLT in PDE and PC-relative PLT in PIE can be used as function
address, there is no need for dynamic PC-relative relocation against
a dynamic function definition in PIE. Linker should resolve PC-relative
reference to its PLT address.
NB: i386 has non-PIC PLT and PIC PLT. Only non-PIC PLT in PDE can
be used as function address. PIC PLT in PIE can't be used as
function address.
bfd/
PR ld/22842
* elf32-i386.c (elf_i386_check_relocs): Pass FALSE for non
PC-relative PLT to NEED_DYNAMIC_RELOCATION_P.
* elf64-x86-64.c (elf_x86_64_check_relocs): Create PLT for
R_X86_64_PC32 reloc against dynamic function in data section.
Pass TRUE for PC-relative PLT to NEED_DYNAMIC_RELOCATION_P.
(elf_x86_64_relocate_section): Use PLT for R_X86_64_PC32 reloc
against dynamic function in data section.
* elfxx-x86.c (elf_x86_allocate_dynrelocs): Use PLT in PIE as
function address only if pcrel_plt is true.
(_bfd_x86_elf_link_hash_table_create): Set pcrel_plt.
* elfxx-x86.h (NEED_DYNAMIC_RELOCATION_P): Add PCREL_PLT for
PC-relative PLT. If PLT is PC-relative, don't generate dynamic
PC-relative relocation against a function definition in data
secton in PIE. Remove the obsolete comments.
(elf_x86_link_hash_table): Add pcrel_plt.
ld/
PR ld/22842
* testsuite/ld-i386/i386.exp: Run PR ld/22842 tests.
* testsuite/ld-x86-64/x86-64.exp: Likewise.
* testsuite/ld-i386/pr22842a.c: New file.
* testsuite/ld-i386/pr22842b.S: Likewise.
* testsuite/ld-x86-64/pr22842a.c: Likewise.
* testsuite/ld-x86-64/pr22842a.rd: Likewise.
* testsuite/ld-x86-64/pr22842b.S: Likewise.
* testsuite/ld-x86-64/pr22842b.rd: Likewise.
If a symbol is not defined in a regular file, and we are not generating
a shared library, then set the symbol to its location in the .plt. This
is required to make function pointers compare as equal between the normal
executable and the shared library.
* elfxx-x86.c (elf_x86_allocate_dynrelocs): Check bfd_link_dll,
instead of bfd_link_pic, for building shared library.
Since there is no need to prepare for PLT branch on x86-64, generate
R_X86_64_PLT32, instead of R_X86_64_PC32, if possible, which can be
used as a marker for 32-bit PC-relative branches.
To compile Linux kernel, this patch:
From: "H.J. Lu" <hjl.tools@gmail.com>
Subject: [PATCH] x86: Treat R_X86_64_PLT32 as R_X86_64_PC32
On i386, there are 2 types of PLTs, PIC and non-PIC. PIE and shared
objects must use PIC PLT. To use PIC PLT, you need to load
_GLOBAL_OFFSET_TABLE_ into EBX first. There is no need for that on
x86-64 since x86-64 uses PC-relative PLT.
On x86-64, for 32-bit PC-relative branches, we can generate PLT32
relocation, instead of PC32 relocation, which can also be used as
a marker for 32-bit PC-relative branches. Linker can always reduce
PLT32 relocation to PC32 if function is defined locally. Local
functions should use PC32 relocation. As far as Linux kernel is
concerned, R_X86_64_PLT32 can be treated the same as R_X86_64_PC32
since Linux kernel doesn't use PLT.
is needed. It is available on hjl/plt32/master branch at
https://github.com/hjl-tools/linux
bfd/
PR gas/22791
* elf64-x86-64.c (is_32bit_relative_branch): Removed.
(elf_x86_64_relocate_section): Check PIC relocations in PIE.
Remove is_32bit_relative_branch usage. Disallow PC32 reloc
against protected function in shared object.
gas/
PR gas/22791
* config/tc-i386.c (need_plt32_p): New function.
(output_jump): Generate BFD_RELOC_X86_64_PLT32 if possible.
(md_estimate_size_before_relax): Likewise.
* testsuite/gas/i386/reloc64.d: Updated.
* testsuite/gas/i386/x86-64-jump.d: Likewise.
* testsuite/gas/i386/x86-64-mpx-branch-1.d: Likewise.
* testsuite/gas/i386/x86-64-mpx-branch-2.d: Likewise.
* testsuite/gas/i386/x86-64-relax-2.d: Likewise.
* testsuite/gas/i386/x86-64-relax-3.d: Likewise.
* testsuite/gas/i386/ilp32/reloc64.d: Likewise.
* testsuite/gas/i386/ilp32/x86-64-branch.d: Likewise.
ld/
PR gas/22791
* testsuite/ld-x86-64/mpx1c.rd: Updated.
* testsuite/ld-x86-64/pr22791-1.err: New file.
* testsuite/ld-x86-64/pr22791-1a.c: Likewise.
* testsuite/ld-x86-64/pr22791-1b.s: Likewise.
* testsuite/ld-x86-64/pr22791-2.rd: Likewise.
* testsuite/ld-x86-64/pr22791-2a.s: Likewise.
* testsuite/ld-x86-64/pr22791-2b.c: Likewise.
* testsuite/ld-x86-64/pr22791-2c.s: Likewise.
* testsuite/ld-x86-64/x86-64.exp: Run PR ld/22791 tests.
Remove `-Wshadow' compilation errors:
cc1: warnings being treated as errors
.../bfd/wasm-module.c: In function 'wasm_scan_name_function_section':
.../bfd/wasm-module.c:312: error: declaration of 'index' shadows a global declaration
/usr/include/string.h:303: error: shadowed declaration is here
.../bfd/wasm-module.c: In function 'wasm_register_section':
.../bfd/wasm-module.c:494: error: declaration of 'index' shadows a global declaration
/usr/include/string.h:303: error: shadowed declaration is here
.../bfd/wasm-module.c: In function 'wasm_compute_custom_section_file_position':
.../bfd/wasm-module.c:523: error: declaration of 'index' shadows a global declaration
/usr/include/string.h:303: error: shadowed declaration is here
and:
cc1: warnings being treated as errors
.../opcodes/wasm32-dis.c: In function 'print_insn_wasm32':
.../opcodes/wasm32-dis.c:272: error: declaration of 'index' shadows a global declaration
/usr/include/string.h:303: error: shadowed declaration is here
make[4]: *** [wasm32-dis.lo] Error 1
which for versions of GCC before 4.8 prevent support for the WebAssembly
target from being built. See also GCC PR c/53066.
bfd/
* wasm-module.c (wasm_scan_name_function_section): Rename
`index' local variable to `idx'.
opcodes/
* wasm32-dis.c (print_insn_wasm32): Rename `index' local
variable to `function_index'.
This fixes the case where all of a group is removed with ld -r, the
situation in the PR, and failures where part of a group is removed
that contain relocs.
bfd/
PR 22836
* elf.c (_bfd_elf_fixup_group_sections): Account for removed
relocation sections. If size reduces to just the flag word,
remove that too and mark with SEC_EXCLUDE.
* elflink.c (bfd_elf_final_link): Strip empty group sections.
binutils/
* testsuite/binutils-all/group-7.s,
* testsuite/binutils-all/group-7a.d,
* testsuite/binutils-all/group-7b.d,
* testsuite/binutils-all/group-7c.d: New tests.
* testsuite/binutils-all/objcopy.exp: Run them.
ld/
* testsuite/ld-elf/pr22836-2.d,
* testsuite/ld-elf/pr22836-2.s: New test.
lld lays out the relro segment differently to GNU ld, not bothering to
include the first few bytes of .got.plt and padding out to a page at
the end of the segment. This patch teaches binutils to recognize the
different (and somewhat inferior) layout as valid.
bfd/
PR 22829
* elf.c (assign_file_positions_for_non_load_sections): Rewrite
PT_GNU_RELRO setup.
ld/
* testsuite/ld-x86-64/pr14207.d: Adjust relro p_filesz.
See email thread starting here: https://www.sourceware.org/ml/binutils/2018-01/msg00001.html
include * coff/msdos.h: New header.
* coff/pe.h: Move common defines to msdos.h.
* coff/powerpc.h: Likewise.
bfd * i386msdos.c (msdos_mkobject); New function.
(msdos_object_p): New function.
(i386_msdos_vec): Use msdos_object_p as the check_format
function.
* peicode.h: Rename external_PEI_DOS_hdr, DOSMAGIC, and
NT_SIGNATURE to external_DOS_hdr, IMAGE_DOS_SIGNATURE, and
IMAGE_NT_SIGNATURE.
* peXXigen.c: Likewise.
* coff-ia64.c: Likewise.
There are 2 failures left in the linker testsuite on SPARC64/Linux and
they are caused by 2 different issues leading to the same end effect:
the overflow of the relocation section for the GOT, i.e. the linker
generates too many dynamic relocations for the GOT wrt the size of the
relocation section, leading to memory corruption and missing relocations
in the final binary.
The first issue was introduced by:
https://sourceware.org/ml/binutils/2017-06/msg00368.html
which makes the linker generate more R_SPARC_RELATIVE relocations for
the GOT without adjusting the size of the relocation section. This is
fixed by (1) preventively adjusting this size in allocate_dynrelocs and
(2) generating R_SPARC_NONE if needed when R_SPARC_GOTDATA_OP is relaxed.
The second issue is that we generate a GOT relocation for an undefined
weak symbol with non-default visibility in a PIC binary without accounting
for that in the size of the relocation section. Since the address of the
symbol should resolve to 0 at run time, it is fixed by not generating the
relocation at all, i.e. leaving the GOT entry zeroed.
bfd/
* elfxx-sparc.c (UNDEFINED_WEAK_RESOLVED_TO_ZERO): Reorder conditions.
(sparc_elf_append_rela): Assert that there is enough room in section.
(_bfd_sparc_elf_copy_indirect_symbol): Fix formatting.
(_bfd_sparc_elf_adjust_dynamic_symbol): Minor tweak.
(allocate_dynrelocs): Remove outdated comments and reorder conditions.
For a symbol subject to a GOT relocation, reserve a slot in the
relocation section if the symbol isn't dynamic and we are in PIC mode.
(_bfd_sparc_elf_relocate_section) <R_SPARC_GOTDATA_OP>: If relocation
is relaxed and a slot was reserved, generate a R_SPARC_NONE relocation.
<R_SPARC_GOTDATA_OP_HIX22>: Adjust comments.
<R_SPARC_PC10>: Reorder conditions. Remove always-false assertion.
(_bfd_sparc_elf_finish_dynamic_symbol): Rename local_undefweak into
resolved_to_zero. Do not generate a dynamic GOT relocation for an
undefined weak symbol with non-default visibility. Remove superfluous
'else' and fix formatting.
Solaris requires to keep _GLOBAL_OFFSET_TABLE_ even if it isn't used.
This patch detects Solaris target and keeps _GLOBAL_OFFSET_TABLE_ for
Solaris.
* elf32-i386.c (elf32_i386_copy_solaris_special_section_fields):
New prototype.
(elf_i386_link_setup_gnu_properties): Set need_global_offset_table
for Solaris.
* elf64-x86-64.c (elf64_x86_64_copy_solaris_special_section_fields):
New prototype.
(elf_x86_64_link_setup_gnu_properties): Set
need_global_offset_table for Solaris.
* elfxx-x86.c (_bfd_x86_elf_size_dynamic_sections): Keep the
unused _GLOBAL_OFFSET_TABLE_ for Solaris.
(_bfd_x86_elf_link_setup_gnu_properties): Copy
need_global_offset_table.
* elfxx-x86.h (elf_x86_link_hash_table): Add
need_global_offset_table.
(elf_x86_init_table): Likewise.
This reverts most of commit 1be5d8d3bb.
Left in place are addition of --no-plt-align to some ppc32 ld tests
and the ld.texinfo --no-plt-thread-safe fix.
This is -fpie -pie generating dynamic relocations in the text section,
simply because no TLS transitions are applied in PIE mode. The meat
of the patch is to turn calls to bfd_link_pic (info) in TLS-related code
into !bfd_link_executable (info) and there are quite a lot of them...
bfd/
* elfxx-sparc.c (sparc_elf_tls_transition): Turn call to bfd_link_pic
into call to !bfd_link_executable and tidy up.
(_bfd_sparc_elf_check_relocs): Fix formatting and tidy up.
<R_SPARC_TLS_LE_HIX22>: Turn call to bfd_link_pic into call to
!bfd_link_executable.
<R_SPARC_TLS_IE_HI22>: Likewise.
<GOT relocations>: Remove useless code, tidy and merge blocks.
<R_SPARC_TLS_GD_CALL>: Turn call to bfd_link_pic into call to
!bfd_link_executable.
<R_SPARC_WPLT30>: Tidy up.
(_bfd_sparc_elf_gc_mark_hook): Turn call to bfd_link_pic into call
to !bfd_link_executable.
(allocate_dynrelocs): Likewise.
(_bfd_sparc_elf_relocate_section): Fix formatting and tidy up.
<R_SPARC_TLS_GD_HI22>: Merge into...
<R_SPARC_TLS_GD_LO10>: ...this. Adjust 4th argument in call to
sparc_elf_tls_transition and remove redundant code.
<R_SPARC_TLS_LDM_HI22>: Turn call to bfd_link_pic into call to
!bfd_link_executable.
<R_SPARC_TLS_LDO_HIX22>: Likewise.
<R_SPARC_TLS_LE_HIX22>: Likewise. Tidy up.
<R_SPARC_TLS_LDM_CALL>: Likewise.
<R_SPARC_TLS_GD_CALL>: Likewise. Tidy up.
<R_SPARC_TLS_GD_ADD>: Likewise.
<R_SPARC_TLS_LDM_ADD>: Likewise.
<R_SPARC_TLS_LDO_ADD>: Likewise.
<R_SPARC_TLS_IE_LD>: Likewise.
ld/
* testsuite/ld-elf/tls.exp (AFLAGS_PIC): Define on SPARC.
(pr22263-1): Pass AFLAGS_PIC to the assembler.
* testsuite/ld-sparc/tlspie32.s: Add test for other 3 transitions.
* testsuite/ld-sparc/tlspie32.dd: Adjust to above.
* testsuite/ld-sparc/tlspie64.s: Add test for other 3 transitions.
* testsuite/ld-sparc/tlspie64.dd: Adjust to above.
PR 22789
* elfxx-mips.c (_bfd_mips_elf_find_nearest_line): If the dwarf
functions failed to find the function name, try the generic elf
find function instead.
GCC 8 will bring a new warning option which will detect possible
overflow and truncation on string manipulation functions. For more
details, see:
https://gcc.gnu.org/ml/gcc-patches/2017-08/msg00471.html
While compiling BFD with it, I can see one place on bfd/coff-rs6000.c
where the warning is triggered. This:
(void) strncpy (fhdr.magic, XCOFFARMAG, SXCOFFARMAG);
will not include the trailing NUL on fhdr.magic, but that's fine
because it's a magic number. The fix is trivial: just use memcpy
instead.
OK to push?
2018-02-06 Sergio Durigan Junior <sergiodj@redhat.com>
* coff-rs6000.c (xcoff_write_archive_contents_old): Use
'memcpy' instead of 'strncpy' when writing the magic number.
PR 22794
* opncls.c (bfd_get_debug_link_info_1): Check the size of the
section before attempting to read it in.
(bfd_get_alt_debug_link_info): Likewise.
The nm utility supports -l for using debug information to obtain file and line information for each symbol, if available.
We have a tool that consumes this information and displays it.
This identified a problem with the 'nm' utility.
When a source is compiled with -O2, functions can be inlined. The compiler also produces an uninlined copy of the function, normally for linking to other object files.
In the case of DWARF2 debug information, the compiler generates debug information to describe a function. If that function is inlined, the compiler then references that debug information from the inlined and uninlined copies of the routine through the use of the DW_AT_abstract_origin reference.
When nm is used on such a file, it is not able to find file and line information because that information is present in the common debug information and not at each actual implementation of the function.
The 'nm' utility only retrieves the name of the function from the abstract origin debug information and no more.
What I am proposing is to modify the find_abstract_instance_name() function (which I renamed to find_abstract_instance() ) to return the name of the function as well as any file and line information. The routine is already parsing all of the debug information in the abstract instance, so it is easy to pick up the file and line information at that time. If, for some reason, the file and line information is not present, the routine behaves as before.
For example, if I have a simple test case:
int foo(int j)
{
if (j < 15)
j += j << 2;
else
j += j << 6;
return j;
}
int main (int argc,char **argv)
{
int i = argc;
i += foo(i);
return i;
}
If that test case is compiled with -O2 and then 'nm -l' reads that executable, it currently produces this symbol output (ignoring a lot of library symbols):
8048400 T foo
080482e0 T main /scratch/pcarroll/its254/test/mytest.c:12
If I modify 'nm' to return file and line information for abstract instances, it produces the following output:
08048400 T foo /scratch/pcarroll/its254/test/mytest.c:1
080482e0 T main /scratch/pcarroll/its254/test/mytest.c:12
--------------------------------------------------------------------------
bfd * bfd/dwarf2.c (find_abstract_name): Modified to return file and
line information in addition to name, if they can be found.
The assumption that R_AARCH64_ABS16 and R_AARCH64_ABS32 relocation in LP64 abi
will be used to generate an address does not hold for absolute symbol.
In this case, it is a value fixed at static linking time.
The condition to check the relocations is relax to allow absolute symbol and
undefined symbol case.
bfd/
2018-02-05 Renlin Li <renlin.li@arm.com>
PR ld/22764
* elfnn-aarch64.c (elfNN_aarch64_check_relocs): Relax the
R_AARCH64_ABS32 and R_AARCH64_ABS16 for absolute symbol. Apply the
check for writeable section as well.
ld/
2018-02-05 Renlin Li <renlin.li@arm.com>
PR ld/22764
* testsuite/ld-aarch64/emit-relocs-258.s: Define symbol as an address.
* testsuite/ld-aarch64/emit-relocs-259.s: Likewise.
* testsuite/ld-aarch64/aarch64-elf.exp: Run new test.
* testsuite/ld-aarch64/pr22764.s: New.
* testsuite/ld-aarch64/pr22764.d: New.
Since _GLOBAL_OFFSET_TABLE_ may be referenced implicitly on x86,
checking ref_regular_nonweak leaves the unused _GLOBAL_OFFSET_TABLE_
in output. This patch checks explicit GOT references instead.
ld-i386/discarded1.s and ld-x86-64/discarded1.s are updated to avoid
linker optimization which removes GOT references.
bfd/
PR ld/22782
* elf32-i386.c (elf_i386_check_relocs): Set got_referenced if
_GLOBAL_OFFSET_TABLE_ is referenced or GOT is needed to resolve
undefined weak symbol to 0.
* elf64-x86-64.c (elf_x86_64_check_relocs): Set got_referenced
if _GLOBAL_OFFSET_TABLE_ is referenced.
* elfxx-x86.c (_bfd_x86_elf_size_dynamic_sections): Check
got_referenced instead of ref_regular_nonweak. Remove the
unused _GLOBAL_OFFSET_TABLE_ from symbol table.
* elfxx-x86.h (elf_x86_link_hash_table): Add got_referenced.
ld/
PR ld/22782
* testsuite/ld-i386/discarded1.s: Replace mov with div.
* testsuite/ld-x86-64/discarded1.s: Likewise.
* testsuite/ld-i386/i386.exp: Run pr22782.
* testsuite/ld-i386/load1-nacl.d: Updated for removing
_GLOBAL_OFFSET_TABLE_ from output.
* testsuite/ld-i386/load1.d: Likewise.
* testsuite/ld-x86-64/load1a-nacl.d: Likewise.
* testsuite/ld-x86-64/load1a.d: Likewise.
* testsuite/ld-x86-64/load1b-nacl.d: Likewise.
* testsuite/ld-x86-64/load1b.d: Likewise.
* testsuite/ld-i386/pr22782.d: New file.
* testsuite/ld-i386/pr22782.s: Likewise.
* testsuite/ld-x86-64/pr22782.s: Likewise.
* testsuite/ld-x86-64/pr22782a.d: Likewise.
* testsuite/ld-x86-64/pr22782b.d: Likewise.
* testsuite/ld-x86-64/x86-64.exp: Run pr22782a and pr22782b.
Correct a commit 9d06997adb ("RISC-V: Relax RISCV_PCREL_* to
RISCV_GPREL_*") regression and remove a `-Wmissing-field-initializers'
compilation error:
cc1: warnings being treated as errors
.../bfd/elfnn-riscv.c: In function '_bfd_riscv_relax_pc':
.../bfd/elfnn-riscv.c:3117: error: missing initializer
.../bfd/elfnn-riscv.c:3117: error: (near initialization for 'hi_reloc.hi_addend')
make[4]: *** [elf64-riscv.lo] Error 1
which for versions of GCC before 4.7 prevents support for RISC-V targets
from being built. See also GCC PR c/36750.
bfd/
* elfnn-riscv.c (_bfd_riscv_relax_pc): Use `memset' to
initialize `hi_reloc'.
Report an error when an unsupported `.reginfo' section size is found in
`_bfd_mips_elf_section_processing', removing an assertion that triggers
at elfxx-mips.c:7105 in GAS when assembling input like:
.section .reginfo
.word 0xdeadbeef
and in `objcopy --rename-section' when renaming an incorrectly sized
section to `.reginfo'.
bfd/
* elfxx-mips.c (_bfd_mips_elf_section_processing): For
SHT_MIPS_REGINFO sections don't assert the correct size and
report an error instead.
binutils/
* testsuite/binutils-all/mips/mips-reginfo.d: New test.
* testsuite/binutils-all/mips/mips-reginfo-n32.d: New test.
* testsuite/binutils-all/mips/mips-reginfo.s: New test source.
* testsuite/binutils-all/mips/mips.exp: Run the new tests.
gas/
* testsuite/gas/mips/reginfo-2.d: New test.
* testsuite/gas/mips/reginfo-2-n32.d: New test.
* testsuite/gas/mips/reginfo-2.l: New test stderr output.
* testsuite/gas/mips/reginfo-2.s: New test source.
* testsuite/gas/mips/mips.exp: Run the new tests.
Fix the issue of any failure from `->elf_backend_section_processing'
not being propagated by `_bfd_elf_write_object_contents'. The MIPS
`_bfd_mips_elf_section_processing' handler can actually potentially
fail, however the caller currently ignores that.
bfd/
* elf.c (_bfd_elf_write_object_contents): Propagate a failure
status from `->elf_backend_section_processing'.
bfd/
PR ld/22756
* elfnn-riscv.c (riscv_relax_delete_bytes): New parameter link_info.
If link_info->wrap_hash, check for a duplicate symbol and ignore.
(_bfd_riscv_relax_call, bfd_riscv_relax_lui, _bfd_riscv_relax_tls_le):
Pass new argument to riscv_relax_delete_bytes.
(_bfd_riscv_relax_align, _bfd_riscv_relax_delete): Likewise. Remove
ATTRIBUTE_UNUSED from link_info parameter.
This fixes a "bug" in that nops emitted as part of code optimization
were being relocated. As it happens the relocation value was always
zero so the nop wasn't changed. Whew! I've also moved the use of
"howto" later since I was caught out in some recent code changes with
the howto not matching r_type.
* elf64-ppc.c (ppc64_elf_relocate_section): Don't relocate nops
emitted for toc sequence optimization. Set and use "howto" later.
bfdI would like to fix instances of the following warning, when building
with clang with no special CFLAGS other than -g3 -O0.
/home/emaisin/src/binutils-gdb/bfd/elflink.c:5425:45: error: performing pointer arithmetic on a null pointer has undefined behavior [-Werror,-Wnull-pointer-arithmetic]
return (struct elf_link_hash_entry *) 0 - 1;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^
Replacing those with "(struct elf_link_hash_entry *) -1" gets rid of the
warning. I wanted to check that it didn't change the resulting code, so
I tried to build this:
$ cat test.c
int *before()
{
return (int *) 0 - 1;
}
int *after()
{
return (int *) - 1;
}
$ gcc -c test.c -g
$ objdump -d test.o
test.o: file format elf64-x86-64
Disassembly of section .text:
0000000000000000 <before>:
0: 55 push %rbp
1: 48 89 e5 mov %rsp,%rbp
4: 48 c7 c0 fc ff ff ff mov $0xfffffffffffffffc,%rax
b: 5d pop %rbp
c: c3 retq
000000000000000d <after>:
d: 55 push %rbp
e: 48 89 e5 mov %rsp,%rbp
11: 48 c7 c0 ff ff ff ff mov $0xffffffffffffffff,%rax
18: 5d pop %rbp
19: c3 retq
This shows that the previous code doesn't actually return -1 as the
function documentation says, but the new one does, so it's kind of a
bugfix.
bfd * elf64-ppc.c (ppc64_elf_archive_symbol_lookup): Avoid pointer
arithmetic on NULL pointer.
* elflink.c (_bfd_elf_archive_symbol_lookup,
elf_link_add_archive_symbols): Likewise.
ld * ldexp.c (fold_name, exp_fold_tree_1): Avoid pointer arithmetic
on NULL pointer.
We really need to check for a dynamic def, not only a ref.
See added testcase.
bfd/
* elflink.c (bfd_elf_define_start_stop): Fix check of
def_dynamic.
ld/
* testsuite/ld-elf/pr21964-5.c: New test.
* testsuite/ld-elf/shared.exp: Run it.
Define __start/__stop symbols if they are referenced by shared objects,
not if they are also defined in shared objects.
bfd/
PR ld/21964
* elflink.c (bfd_elf_define_start_stop): Check if __start and
__stop symbols are referenced by shared objects.
ld/
PR ld/21964
* testsuite/ld-elf/pr21964-4.c: New file.
* testsuite/ld-elf/shared.exp: Run pr21964-4 test on Linux.
We can't map different disk pages into the same memory page; The last
page mapped will simply overwrite any previous pages. The
executable/non-executable new_segment test ignored this fact, leading
to a ld.so segfault on hppa when .dynamic is overwritten with zeros.
This patch moves existing tests for demand paging with lma on the same
memory page, to a new test performed before any case where we want a
new segment due to protection or loadable conflicts.
PR 22758
* elf.c (_bfd_elf_map_sections_to_segments): Don't start a new
segment when demand paged with lma on the same page. Test this
before load/non-load, executable/non-executable,
writable/non-writable tests and simplify. Delete bogus relro
condition in writable/non-writable test. Delete outdated
comment. Formatting.
bfd/
* elflink.c (bfd_elf_define_start_stop): Make __start and __stop
symbols dynamic.
ld/
* testsuite/ld-elf/pr21964-3a.c: New file.
* testsuite/ld-elf/pr21964-3c.c: New file.
* testsuite/ld-elf/shared.exp: Run new __start/__stop testcase.
This patch fixes a case where a user had a C-representable named
section in both the executable and shared libraries, and of course
wanted the size of the local section in the executable, not the
dynamic section. It does mean that __start and __stop symbols don't
behave exactly like PROVIDEd symbols, but I think that's a reasonable
difference particularly since this is the way they used to behave.
* elflink.c (bfd_elf_define_start_stop): Override symbols when
they are defined dynamically.
https://bugzilla.redhat.com/show_bug.cgi?id=1523457
I haven't analyzed this myself, I'm relying on Nick's excellent
analysis. What I believe is happening is that after some number of
stub sizing iterations, a long-branch stub needs to be converted to a
plt-branch, but either due to stub alignment or other stubs shrinking
in size, the stub group section size doesn't change.
That means we exit from ppc64_elf_size_stubs after sizing with an
incorrect layout, in fact the additional .branch_lt entry overlays
.got! Since .TOC. is normally set to .got + 0x8000 the stub sizing
code decides that entry is within +/-32k of the TOC pointer and so a
three insn stub is sufficient. When we come to build the stubs using
a correct non-overlaying layout, a four insn plt-branch stub is
generated and the stub group size doesn't match that calculated
earlier.
* elf64-ppc.c (ppc64_elf_size_stubs): Iterate sizing when
.branch_lt changes size.
There are actually 2 different bugs:
1. TLS transition is broken in PIE mode.
2. TLS is broken in PIC/PIE mode when the __tls_get_addr symbol
is versioned (as is the case on Linux and Solaris at least).
The 1st bug is fixed by reverting the problematic change for now
(note that the associated test doesn't pass on SPARC because of another
issue so there is no formal regression in the testsuite). The 2nd bug
is fixed by changing the call to _bfd_generic_link_add_one_symbol
on __tls_get_addr into a mere lookup in _bfd_sparc_elf_check_relocs.
bfd/
* elfxx-sparc.c (_bfd_sparc_elf_check_relocs) <R_SPARC_TLS_GD_CALL>:
Do a mere lookup of the __tls_get_addr symbol instead of adding it.
Revert
2017-10-19 H.J. Lu <hongjiu.lu@intel.com>
PR ld/22263
* elfxx-sparc.c (sparc_elf_tls_transition): Replace
bfd_link_pic with !bfd_link_executable, !bfd_link_pic with
bfd_link_executable for TLS check.
(_bfd_sparc_elf_check_relocs): Likewise.
(allocate_dynrelocs): Likewise.
(_bfd_sparc_elf_relocate_section): Likewise.
ld/
* testsuite/ld-sparc/sparc.exp (32-bit: Helper shared library):
Link with a version script.
(32-bit: TLS -fpie): New test.
(64-bit: Helper shared library): Link with a version script.
(64-bit: TLS -fpie): New test.
(64-bit: GOTDATA relocations): Pass -Av9 to the assembler.
* testsuite/ld-sparc/tlslib.ver: New file.
* testsuite/ld-sparc/tlspie32.dd: Likewise.
* testsuite/ld-sparc/tlspie32.s: Likewise.
* testsuite/ld-sparc/tlspie64.dd: Likewise.
* testsuite/ld-sparc/tlspie64.s: Likewise.
* testsuite/ld-sparc/tlssunbin32.dd: Adjust for versioned symbol.
* testsuite/ld-sparc/tlssunbin32.rd: Likewise.
* testsuite/ld-sparc/tlssunbin32.sd: Likewise.
* testsuite/ld-sparc/tlssunbin64.dd: Likewise.
* testsuite/ld-sparc/tlssunbin64.rd: Likewise.
* testsuite/ld-sparc/tlssunbin64.sd: Likewise.
Update a stale reference to `mips_elf32_section_processing', following a
merge of the function into `_bfd_mips_elf_section_processing' made with
commit 103186c62b ("PATCH for MIPS 64-bit ABI suport"),
<https://sourceware.org/ml/binutils/1999-q3/msg00072.html>.
bfd/
* elfxx-mips.c (_bfd_mips_elf_final_link): Update a stale
`mips_elf32_section_processing' comment reference.
We need to check the versioned __tls_get_addr symbol when looking up
"__tls_get_addr".
bfd/
PR ld/22721
* elfxx-x86.c (_bfd_x86_elf_link_check_relocs): Check the
versioned __tls_get_addr symbol.
ld/
PR ld/22721
* testsuite/ld-plugin/lto.exp: Run PR ld/22721 tests.
* testsuite/ld-plugin/pr22721.t: New file.
* testsuite/ld-plugin/pr22721a.s: Likewise.
* testsuite/ld-plugin/pr22721b.c: Likewise.
Asking for ppc32 plt call stubs to be aligned at 32 byte boundaries
didn't quite work. For ld.bfd they were spaced 32 bytes apart, but
only started on a 16 byte boundary. ld.gold also didn't get it right.
Finding that bug made me check over the ppc64 plt stub alignment,
where I found that negative values for alignment (meaning align to
minimize boundary crossing) were not accepted. Since no one has
complained about that, I guess I could have removed the feature from
ld.bfd documentation, but I've opted instead to correct the code.
I've also added an optional alignment paramenter for ppc32
--plt-align, for some consistency with gold and ppc64 ld.bfd.
bfd/
* elf32-ppc.c (ppc_elf_create_glink): Correct alignment of .glink.
* elf64-ppc.c (ppc64_elf_size_stubs): Handle negative plt_stub_align.
(ppc64_elf_build_stubs): Likewise.
gold/
* powerpc.cc (param_plt_align): New function supplying default
--plt-align values. Use it..
(Stub_table::plt_call_align): ..here, and..
(Output_data_glink::global_entry_align): ..here.
(Stub_table::stub_align): Correct 32-bit minimum alignment.
ld/
* emultempl/ppc32elf.em: Support optional --plt-align arg.
* emultempl/ppc64elf.em: Support negative --plt-align arg.
This is in preparation for the next patch adding Spectre variant 2
mitigation for PowerPC and PowerPC64. Besides tidying code involved
in stub output (to reduce the number of places where bctr is output),
the patch adds some user visible features:
1) PowerPC64 ELFv2 global entry stubs now are aligned under the
control of --plt-align, with a default alignment of 32 bytes.
2) PowerPC64 __glink_PLTresolve is no longer padded out with nops.
3) PowerPC32 PLT stubs are aligned under the control of --plt-align,
with the default alignment being 16 bytes as before.
4) The PowerPC32 branch/nop table emitted before __glink_PLTresolve
is now smaller in many cases. It was sized incorrectly when the
__tls_get_addr_opt stub was used, and unnecessarily included space
for local ifuncs.
bfd/
* elf32-ppc.c (GLINK_ENTRY_SIZE): Add parameters, handle
__tls_get_addr_opt, and alignment sizing.
(TLS_GET_ADDR_GLINK_SIZE): Delete.
(is_nonpic_glink_stub): Don't use GLINK_ENTRY_SIZE.
(ppc_elf_get_synthetic_symtab): Recognize stubs spaced at 4, 6,
or 8 insns.
(ppc_elf_link_hash_table_create): Init new ppc_elf_params field.
(allocate_dynrelocs): Use new GLINK_ENTRY_SIZE.
(ppc_elf_size_dynamic_sections): Likewise. Size branch table
by PLT reloc count.
(write_glink_stub): Handle __tls_get_addr_opt stub.
Pad out to size given by GLINK_ENTRY_SIZE.
(ppc_elf_relocate_section): Adjust write_glink_stub call.
(ppc_elf_finish_dynamic_symbol): Likewise.
(ppc_elf_finish_dynamic_sections): Write PLTresolve without using
insn array since so many need rewriting.
* elf32-ppc.h (struct ppc_elf_params): Add plt_stub_align.
* elf64-ppc.c (GLINK_PLTRESOLVE_SIZE): Rename from
GLINK_CALL_STUB_SIZE. Add htab param and evaluate to size without
nops. Adjust all uses.
(ppc64_elf_get_synthetic_symtab): Don't use GLINK_CALL_STUB_SIZE
in glink_vma calculation.
(struct ppc_link_hash_table): Add global_entry section pointer.
(create_linkage_sections): Create separate section for global
entry stubs.
(PPC_LO, PPC_HI, PPC_HA): Move earlier.
(size_global_entry_stubs): Handle sizing for aligned stubs.
(ppc64_elf_size_dynamic_sections): Handle global_entry alloc,
and don't stash end of glink branch table in rawsize.
(ppc_build_one_stub): Rewrite stub size calculations.
(build_global_entry_stubs): Use new section.
(ppc64_elf_build_stubs): Don't pad __glink_PLTresolve with nops.
Build lazy link stubs out to end of section. Build global entry
stubs in new section.
gold/
* options.h (plt_align): Support for PowerPC32 too.
* powerpc.cc (Stub_table::stub_align): Heed --plt-align for 32-bit.
(Stub_table::plt_call_size, branch_stub_size): Tidy.
(Stub_table::plt_call_align): Implement using stub_align.
(Output_data_glink::global_entry_align): New function.
(Output_data_glink::global_entry_off): New function.
(Output_data_glink::global_entry_address): Use global_entry_off.
(Output_data_glink::pltresolve_size): New function, replacing
pltresolve_size_ constant. Update all uses.
(Output_data_glink::add_global_entry): Align offset.
(Output_data_glink::set_final_data_size): Use global_entry_align.
(Stub_table::do_write): Don't pad __glink_PLTrelsolve with nops.
Tidy stub output. Use global_entry_off.
ld/
* emultempl/ppc32elf.em (params): Init new field.
(enum ppc32_opt): New enum to define OPTION_* values. Add
OPTION_PLT_ALIGN and OPTION_NO_PLT_ALIGN.
(PARSE_AND_LIST_LONGOPTS): Handle new options.
(PARSE_AND_LIST_ARGS_CASES): Likewise.
(PARSE_AND_LIST_OPTIONS): Likewise. Break up help output.
* emultempl/ppc64elf.em (ppc_add_stub_section): Init alignment
correctly for negative --plt-stub-align.
* testsuite/ld-powerpc/elfv2exe.d,
* testsuite/ld-powerpc/elfv2so.d,
* testsuite/ld-powerpc/relbrlt.d,
* testsuite/ld-powerpc/relbrlt.s,
* testsuite/ld-powerpc/tlsexe.d,
* testsuite/ld-powerpc/tlsexe.r,
* testsuite/ld-powerpc/tlsexe32.d,
* testsuite/ld-powerpc/tlsexe32.g,
* testsuite/ld-powerpc/tlsexe32.r,
* testsuite/ld-powerpc/tlsexetoc.d,
* testsuite/ld-powerpc/tlsexetoc.r,
* testsuite/ld-powerpc/tlsopt5_32.d,
* testsuite/ld-powerpc/tlsso.d,
* testsuite/ld-powerpc/tlstocso.d: Update for changed stub order.
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