A customer reported a case where addr2line was very slow. We tracked
this down to some N^2 behavior in _bfd_dwarf2_find_symbol_bias in the
unusual case where no function can be found.
This patch fixes the bug, and reduces the runtime for a particular
request from 127 seconds to 1 second.
bfd/ChangeLog
2019-08-19 Tom Tromey <tromey@adacore.com>
* dwarf2.c (_bfd_dwarf2_find_symbol_bias): Create hash table
holding symbols.
These are done in ppc64_elf_edit_toc, which now also garbage collects
unused GOT entries. The checks for legitimate instructions weren't
being done for the GOT relocs, unless the file also happened to have a
toc section.
* elf64-ppc.c (struct ppc64_elf_obj_tdata): Rename has_gotrel
to has_optrel.
(struct _ppc64_elf_section_data): Likewise.
(ppc64_elf_check_relocs): Set has_optrel for more relocs.
(ppc64_elf_edit_toc): Do ha/lo insn checks in GOT loop rather
than TOC loop. Check PLT16 insns too.
commit 83924b3846361f2f76f9a6e7b5afa01c0eebbd4f
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Tue Feb 5 18:45:23 2019 -0800
x86-64: Restore PIC check for PCREL reloc against protected symbol
moved PIC check for PC-relative relocations to elf_x86_64_check_relocs.
Since linker defined symbols may not be processed at the time, we need
to move the check back to elf_x86_64_relocate_section.
bfd/
PR ld/24905
* elf64-x86-64.c (elf_x86_64_check_relocs): Move PIC check for
PC-relative relocations back to ...
(elf_x86_64_relocate_section): Here.
ld/
PR ld/24905
* testsuite/ld-x86-64/pr24905-x32.d: New file.
* testsuite/ld-x86-64/pr24905.d: Likewise.
* testsuite/ld-x86-64/pr24905.s: Likewise.
* testsuite/ld-x86-64/pr24905.t: Likewise.
* testsuite/ld-x86-64/x86-64.exp: Run pr24905 and pr24905-x32.
2019-08-16 Martin Liska <mliska@suse.cz>
PR ld/24912
* elflink.c: Report error only for not relocatable.
* linker.c (_bfd_generic_link_add_one_symbol): Do not handle
here lto_slim_object as it's handled in caller.
2019-08-16 Martin Liska <mliska@suse.cz>
PR ld/24912
* object.cc (big_endian>::do_layout): Do not report error,
but only set a flag.
(big_endian>::do_add_symbols): Report error only for when
relocatable.
Given R_PPC_ADDR32 or R_PPC_UADDR32 relocs, this patch generates
R_PPC_ADDR32 or R_PPC_UADDR32 dynamic relocs from either type
depending on whether r_offset is 4-byte aligned, and similarly for
R_PPC_ADDR16/R_PPC_UADDR16.
* elf32-ppc.c (ppc_elf_relocate_section): Optimize unaligned relocs.
This fixes a problem originally reported at
https://github.com/riscv/riscv-binutils-gdb/issues/173
If you have code linked at address zero, you can have a lui instruction
loading a value 0x800 which gets relaxed to a c.lui which is valid (c.lui 0x1
followed by addi -0x800). Relaxation can reduce the value below 0x800 at which
point the c.lui 0x0 is no longer valid. We can fix this by converting the
c.lui to a c.li which can load 0.
bfd/
* elfnn-riscv.c (perform_relocation) <R_RISCV_RVC_LUI>: If
RISCV_CONST_HIGH_PART (value) is zero, then convert c.lui instruction
to c.li instruction, and use ENCODE_RVC_IMM to set value.
ld/
* testsuite/ld-riscv-elf/c-lui-2.d: New.
* testsuite/ld-riscv-elf/c-lui-2.ld: New.
* testsuite/ld-riscv-elf/c-lui-2.s: New.
* testsuite/ld-riscv-elf/ld-riscv-elf.exp: Run the c-lui-2 test.
A customer program had a DWARF CU that consisted of just a CU DIE,
without any children. In this situation, scan_unit_for_symbols will
try to read past the end of the current CU, and will take use the
first bytes of the next CU as an abbrev, printing an error message.
This patch fixes the bug by changing scan_unit_for_symbols to stop at
the end of the CU rather than the end of the .debug_info section.
bfd/ChangeLog
2019-08-15 Tom Tromey <tromey@adacore.com>
* dwarf2.c (scan_unit_for_symbols): Check for end of CU, not end
of section.
PR 24623
* dwarf2.c (stash_comp_unit): New function, extracted from..
(_bfd_dwarf2_find_nearest_line): ..here.
(find_abstract_instance): Parse comp units and decode line info
as needed.
This parameter might appear to be used to set up offset_size, but
since git commit 024b2372f5 offset_size is either set from the
debug_info data or is set to 4.
* dwarf2.c (_bfd_dwarf2_find_nearest_line): Remove addr_size parameter.
* libbfd-in.h (_bfd_dwarf2_find_nearest_line): Update prototype.
* coffgen.c (coff_find_nearest_line_with_names): Adjust
_bfd_dwarf2_find_nearest_line calls.
* elf.c (_bfd_elf_find_nearest_line, _bfd_elf_find_line): Likewise.
* elf32-arm.c (elf32_arm_find_nearest_line): Likewise.
* elf64-alpha.c (elf64_alpha_find_nearest_line): Likewise.
* elfnn-aarch64.c (elfNN_aarch64_find_nearest_line): Likewise.
* elfxx-mips.c (_bfd_mips_elf_find_nearest_line): Likewise.
* mach-o.c (bfd_mach_o_find_nearest_line): Likewise.
* libbfd.h: Regenerate.
This patch is a reimplementation of [1] which was submitted in 2015 by
Neil Schellenberger. Copyright issue was sorted out [2] last year.
It proposed a new section (.gnu.xhash) and related dynamic tag
(DT_GNU_XHASH). The new section would be virtually identical to the
existing .gnu.hash except for the translation table (xlat) which would
contain correct MIPS .dynsym indexes corresponding to the hashvals in
chains. This is because MIPS ABI imposes a different ordering on the
dynsyms than the one expected by the .gnu.hash section. Another addition
would be a leading word (ngnusyms) which would contain the number of
entries in the translation table.
In this patch, the new section name and dynamic tag are changed to
reflect the fact that the section should be treated as MIPS-specific
(.MIPS.xhash and DT_MIPS_XHASH).
This patch addresses the alignment issue as reported in [3], which is
caused by the leading word added to the .MIPS.xhash section. Leading word
is removed in this patch, and the number of entries in the translation
table is now calculated using DT_MIPS_SYMTABNO dynamic tag (this is
addressed by the corresponding glibc patch).
Suggestions on coding style in [4] were taken into account. Existing
GNU hash testcase was covered, and another one was added in the MIPS
part of the testsuite.
The other major change is reserving MIPS ABI version 5 for .MIPS.xhash,
marking the need of support for .MIPS.xhash in the dynamic linker (again,
addressed in the corresponding glibc patch). This is something which I
am not sure of, especially after reading [5]. I am confused on whether
this ABI version is reserved for IFUNC, or it can be used for this
purpose.
Already mentioned glibc patch is submitted at:
https://sourceware.org/ml/libc-alpha/2019-06/msg00456.html
[1] https://sourceware.org/ml/binutils/2015-10/msg00057.html
[2] https://sourceware.org/ml/binutils/2018-03/msg00025.html
[3] https://sourceware.org/ml/binutils/2016-01/msg00006.html
[4] https://sourceware.org/ml/binutils/2016-02/msg00097.html
[5] https://sourceware.org/ml/libc-alpha/2016-12/msg00853.html
ld * emulparams/elf32bmip.sh: Add .MIPS.xhash section.
* emulparams/elf32bmipn32-defs.sh: Add .MIPS.xhash section.
* emulparams/elf64bmip-defs.sh: Add .MIPS.xhash section.
* emultempl/mipself.em: Remove mips_after_parse function.
* testsuite/ld-elf/hash.d: Update comment.
* testsuite/ld-mips-elf/hash1.d: New test.
* testsuite/ld-mips-elf/hash1.s: Ditto.
* testsuite/ld-mips-elf/hash1a.d: Remove.
* testsuite/ld-mips-elf/hash1b.d: Ditto.
* testsuite/ld-mips-elf/hash1c.d: Ditto
* testsuite/ld-mips-elf/hash2.d: New test.
* testsuite/ld-mips-elf/mips-elf.exp: New tests.
* testsuite/ld-mips-elf/start.s: New test.
bfd * elf-bfd.h (struct elf_backend_data): New members.
* elflink.c (_bfd_elf_link_create_dynamic_sections): Create
.gnu.hash section if necessary.
(struct collect_gnu_hash_codes): New member.
(elf_gnu_hash_process_symidx): New function name.
(elf_renumber_gnu_hash_syms): Ignore local and undefined
symbols. Record xlat location for every symbol which should have
a .MIPS.xhash entry.
(bfd_elf_size_dynamic_sections): Add DT_GNU_HASH dynamic tag to
dynamic section if necessary.
(GNU_HASH_SECTION_NAME): New define.
(bfd_elf_size_dynsym_hash_dynstr): Get .MIPS.xhash section.
Update the section size info.
* elfxx-mips.c (struct mips_elf_hash_sort_data): New members.
(struct mips_elf_link_hash_entry): New member.
(mips_elf_link_hash_newfunc): Initialize .MIPS.xhash translation
table location.
(mips_elf_sort_hash_table): Initialize the pointer to the
.MIPS.xhash section.
(mips_elf_sort_hash_table_f): Populate the .MIPS.xhash
translation table entry with the symbol dynindx.
(_bfd_mips_elf_section_from_shdr): Add SHT_MIPS_XHASH.
(_bfd_mips_elf_fake_sections): Initialize .MIPS.xhash section
info.
(_bfd_mips_elf_create_dynamic_sections): Create .MIPS.xhash
section.
(_bfd_mips_elf_size_dynamic_sections): Add DT_MIPS_XHASH tag to
dynamic section.
(_bfd_mips_elf_finish_synamic_sections): Add DT_MIPS_XHASH.
(_bfd_mips_elf_final_write_processing): Set .MIPS.xhash section
sh_link info.
(_bfd_mips_elf_get_target_dtag): Get DT_MIPS_XHASH tag.
(MIPS_LIBC_ABI_XHASH): New ABI version enum value.
(_bfd_mips_post_process_headers): Mark the ABI version as
MIPS_LIBC_ABI_XHASH if there exists a .MIPS.xhash section,
but not a .hash section.
(_bfd_mips_elf_record_xhash_symbol): New function. Record a
position in the translation table, associated with the hash
entry.
* elfxx-mips.h (literal_reloc_p): Define
elf_backend_record_xhash_symbol backend hook.
* elfxx-target.h: Initialize elf_backend_record_xhash_symbol
backend hook.
include * elf/mips.h (SHT_GNU_XHASH): New define.
(DT_GNU_XHASH): New define.
binutils * readelf.c (get_mips_dynamic_type): Return MIPS_XHASH dynamic type.
(get_mips_section_type_name): Return MI{S_XHASH name string.
(dynamic_section_mips_val): Initialize the .MIPS.xhash dynamic
info.
(process_symbol_table): Initialize the .MIPS.xhash section
pointer. Adjust the readelf output to support the new section.
(process_object): Set the .MIPS.xhash dynamic info to zero.
This patch changes the eBPF linker to provide a relocate_section
function instead of relying on using special functions in relocation
howtos.
Tested in x86_64 host.
No regressions.
bfd/ChangeLog:
2019-08-07 Jose E. Marchesi <jose.marchesi@oracle.com>
* elf64-bpf.c (bpf_elf_relocate_section): New function.
(bpf_elf_insn_disp_reloc): Delete function.
(elf_backend_relocate_section): Define.
bfd/ChangeLog
Ilia Diachkov <ilia.diachkov@optimitech.com>
* elfnn-riscv.c (_bfd_riscv_relax_lui): Set lui relax safety area to
two pages in relro presence.
check_loop_aligned is used during link time relaxation to only allow
transformations that don't violate loop body alignment requirements.
Assembler can relax loops that have too long body by adding instructions
between the loop instruction and the loop body. check_loop_aligned must
check alignment of the first instruction of the actual loop body.
Detect loop / rsr.lend / wsr.lbeg sequence used in assembly time
relaxation and adjust alignment check when it's detected.
bfd/
2019-08-01 Max Filippov <jcmvbkbc@gmail.com>
* elf32-xtensa.c (insn_num_slots, get_rsr_lend_opcode)
(get_wsr_lbeg_opcode): New functions.
(check_loop_aligned): Detect relaxed loops and adjust loop_len
and insn_len for the first actual instruction of the loop.
This fixes two cases where elf_link_add_object_symbols returns an
error, setting the catch-all bfd_error_bad_value without explaining
the error. The second one is an internal error that can only be
caused by a target elf_add_symbol_hook, so make that one abort. The
first one is my PR24339 fix. PR24339 is another of those fuzzing bugs
and the fix I made catches the problem when loading symbols, rather
than when symbols are used in relocs. While ld is correct to reject
the object file as not complying with the ELF standard, let's be a
little more forgiving for dynamic objects.
PR 24857
PR 24339
* elflink.c (elf_link_add_object_symbols): Report an informative
error on finding local symbols with index equal or greater than
symbol table sh_info. Correct comment. Allow such symbols in
dynamic objects. Abort on NULL section for symbol.
This field effectively became usused a long time ago, perhaps as early
as 1994.
* elf-bfd.h (struct output_elf_obj_tdata): Delete "linker" field.
(elf_linker): Don't define.
* elflink.c (bfd_elf_final_link): Don't set elf_linker.
Add linker relaxation. The first relaxation added is converting
GOTPC32 to PCREL relocations. This relaxation doesn't change the size of
the binary.
bfd/
xxxx-xx-xx Claudiu Zissulescu <claziss@synopsys.com>
* elf32-arc.c (bfd_get_32_me): New function.
(bfd_put_32_me): Likewise.
(arc_elf_relax_section): Likewise.
(bfd_elf32_bfd_relax_section): Define.
ld/testsuite/
xxxx-xx-xx Claudiu Zissulescu <claziss@synopsys.com>
* ld-arc/relax-local-pic.d: New test.
* ld-arc/relax-local-pic.s: New file.
I missed some early exits from final_write_processing that mean
_bfd_elf_final_write_processing could be missed.
* elf-vxworks.c (elf_vxworks_final_write_processing): Don't return
early.
* elf32-arc.c (arc_elf_final_write_processing): Likewise.
* elf32-xtensa.c (elf_xtensa_final_write_processing): Likewise.
