commit a7664973b2
Author: Jan Beulich <jbeulich@suse.com>
Date: Mon Apr 26 10:41:35 2021 +0200
x86: correct overflow checking for 16-bit PC-relative relocs
caused linker failure when building 16-bit program in a 32-bit ELF
container. Update GNU_PROPERTY_X86_FEATURE_2_USED with
#define GNU_PROPERTY_X86_FEATURE_2_CODE16 (1U << 12)
to indicate that 16-bit mode instructions are used in the input object:
https://groups.google.com/g/x86-64-abi/c/UvvXWeHIGMA
to indicate that 16-bit mode instructions are used in the object to
allow linker to properly perform relocation overflow check for 16-bit
PC-relative relocations in 16-bit mode instructions.
1. Update x86 assembler to always generate the GNU property note with
GNU_PROPERTY_X86_FEATURE_2_CODE16 for .code16 in ELF object.
2. Update i386 and x86-64 linkers to use 16-bit PC16 relocations if
input object is marked with GNU_PROPERTY_X86_FEATURE_2_CODE16.
bfd/
PR ld/27905
* elf32-i386.c: Include "libiberty.h".
(elf_howto_table): Add 16-bit R_386_PC16 entry.
(elf_i386_rtype_to_howto): Add a BFD argument. Use 16-bit
R_386_PC16 if input has 16-bit mode instructions.
(elf_i386_info_to_howto_rel): Update elf_i386_rtype_to_howto
call.
(elf_i386_tls_transition): Likewise.
(elf_i386_relocate_section): Likewise.
* elf64-x86-64.c (x86_64_elf_howto_table): Add 16-bit
R_X86_64_PC16 entry.
(elf_x86_64_rtype_to_howto): Use 16-bit R_X86_64_PC16 if input
has 16-bit mode instructions.
* elfxx-x86.c (_bfd_x86_elf_parse_gnu_properties): Set
elf_x86_has_code16 if relocatable input is marked with
GNU_PROPERTY_X86_FEATURE_2_CODE16.
* elfxx-x86.h (elf_x86_obj_tdata): Add has_code16.
(elf_x86_has_code16): New.
binutils/
PR ld/27905
* readelf.c (decode_x86_feature_2): Support
GNU_PROPERTY_X86_FEATURE_2_CODE16.
gas/
PR ld/27905
* config/tc-i386.c (set_code_flag): Update x86_feature_2_used
with GNU_PROPERTY_X86_FEATURE_2_CODE16 for .code16 in ELF
object.
(set_16bit_gcc_code_flag): Likewise.
(x86_cleanup): Always generate the GNU property note if
x86_feature_2_used isn't 0.
* testsuite/gas/i386/code16-2.d: New file.
* testsuite/gas/i386/code16-2.s: Likewise.
* testsuite/gas/i386/x86-64-code16-2.d: Likewise.
* testsuite/gas/i386/i386.exp: Run code16-2 and x86-64-code16-2.
include/
PR ld/27905
* elf/common.h (GNU_PROPERTY_X86_FEATURE_2_CODE16): New.
ld/
PR ld/27905
* testsuite/ld-i386/code16.d: New file.
* testsuite/ld-i386/code16.t: Likewise.
* testsuite/ld-x86-64/code16.d: Likewise.
* testsuite/ld-x86-64/code16.t: Likewise.
* testsuite/ld-i386/i386.exp: Run code16.
* testsuite/ld-x86-64/x86-64.exp: Likewise.
The official name for Loongson Architecture is LoongArch, it is better
to use LoongArch instead of Loongson Loongarch for EM_LOONGARCH to avoid
confusion and keep consistent with the various of software in the future.
The official documentation in Chinese:
http://www.loongson.cn/uploadfile/cpu/LoongArch.pdf
The translated version in English:
https://loongson.github.io/LoongArch-Documentation/
binutils/
* readelf.c (get_machine_name): Change Loongson Loongarch to
LoongArch.
include/
* elf/common.h (EM_LOONGARCH): Change Loongson Loongarch to
LoongArch.
Rather than rely on off_t being the right size between the host &
target, have the interface always be 64-bit. We can figure out if
we need to truncate when actually outputting it to the right target.
PR sim/27705
Rather than rely on time_t being the right size between the host &
target, have the interface always be 64-bit. We can figure out if
we need to truncate when actually outputting it to the right target.
The gdb/callback.h & gdb/remote-sim.h headers have nothing to do with
gdb and are really definitions for the libsim API under the sim/ tree.
While gdb uses those headers as a client, it's not specific to it. So
create a new sim/ namespace and move the headers there.
The libiberty hash table includes a helper function for strings, but
no equality function. Consequently, this equality function has been
reimplemented a number of times in both the gcc and binutils-gdb
source trees. This patch adds the function to the libiberty hash
table, as a step toward the goal of removing all the copies.
One change to gcc is included here. Normally I would have put this in
the next patch, but gensupport.c used the most natural name for its
reimplementation of this function, and this can't coexist with the
extern function in libiberty.
include
* hashtab.h (htab_eq_string): Declare.
libiberty
* hashtab.c (htab_eq_string): New function.
The gotha() relocation mnemonic will be outputted by OpenRISC GCC when
using the -mcmodel=large option. This relocation is used along with
got() to generate 32-bit GOT offsets. This increases the previous GOT
offset limit from the previous 16-bit (64K) limit.
This is needed on large binaries where the GOT grows larger than 64k.
bfd/ChangeLog:
PR 21464
* bfd-in2.h: Add BFD_RELOC_OR1K_GOT_AHI16 relocation.
* elf32-or1k.c (or1k_elf_howto_table, or1k_reloc_map): Likewise.
(or1k_final_link_relocate, or1k_elf_relocate_section,
or1k_elf_check_relocs): Likewise.
* libbfd.h (bfd_reloc_code_real_names): Likewise.
* reloc.c: Likewise.
cpu/ChangeLog:
PR 21464
* or1k.opc (or1k_imm16_relocs, parse_reloc): Define parse logic
for gotha() relocation.
include/ChangeLog:
PR 21464
* elf/or1k.h (elf_or1k_reloc_type): Define R_OR1K_GOT_AHI16 number.
opcodes/ChangeLog:
PR 21464
* or1k-asm.c: Regenerate.
gas/ChangeLog:
PR 21464
* testsuite/gas/or1k/reloc-1.s: Add test for new relocation.
* testsuite/gas/or1k/reloc-1.d: Add test result for new
relocation.
Cc: Giulio Benetti <giulio.benetti@benettiengineering.com>
fixup reloc, add tests
Before now, types that could not be encoded in CTF were represented as
references to type ID 0, which does not itself appear in the
dictionary. This choice is annoying in several ways, principally that it
forces generators and consumers of CTF to grow special cases for types
that are referenced in valid dicts but don't appear.
Allow an alternative representation (which will become the only
representation in format v4) whereby nonrepresentable types are encoded
as actual types with kind CTF_K_UNKNOWN (an already-existing kind
theoretically but not in practice used for padding, with value 0).
This is backward-compatible, because CTF_K_UNKNOWN was not used anywhere
before now: it was used in old-format function symtypetabs, but these
were never emitted by any compiler and the code to handle them in libctf
likely never worked and was removed last year, in favour of new-format
symtypetabs that contain only type IDs, not type kinds.
In order to link this type, we need an API addition to let us add types
of unknown kind to the dict: we let them optionally have names so that
GCC can emit many different unknown types and those types with identical
names will be deduplicated together. There are also small tweaks to the
deduplicator to actually dedup such types, to let opening of dicts with
unknown types with names work, to return the ECTF_NONREPRESENTABLE error
on resolution of such types (like ID 0), and to print their names as
something useful but not a valid C identifier, mostly for the sake of
the dumper.
Tests added in the next commit.
include/ChangeLog
2021-05-06 Nick Alcock <nick.alcock@oracle.com>
* ctf.h (CTF_K_UNKNOWN): Document that it can be used for
nonrepresentable types, not just padding.
* ctf-api.h (ctf_add_unknown): New.
libctf/ChangeLog
2021-05-06 Nick Alcock <nick.alcock@oracle.com>
* ctf-open.c (init_types): Unknown types may have names.
* ctf-types.c (ctf_type_resolve): CTF_K_UNKNOWN is as
non-representable as type ID 0.
(ctf_type_aname): Print unknown types.
* ctf-dedup.c (ctf_dedup_hash_type): Do not early-exit for
CTF_K_UNKNOWN types: they have real hash values now.
(ctf_dedup_rwalk_one_output_mapping): Treat CTF_K_UNKNOWN types
like other types with no referents: call the callback and do not
skip them.
(ctf_dedup_emit_type): Emit via...
* ctf-create.c (ctf_add_unknown): ... this new function.
* libctf.ver (LIBCTF_1.2): Add it.
bfd/ChangeLog:
* coff-rs6000.c (_bfd_xcoff_swap_aux_in): Add errors for
unsupported storage class or auxialiry entries.
Improve and adapt to new aux structures.
Add C_DWARF support.
(_bfd_xcoff_swap_aux_out): Likewise.
* coff64-rs6000.c (_bfd_xcoff64_swap_aux_in): Likewise.
(_bfd_xcoff64_swap_aux_out): Likewise.
binutils/ChangeLog:
* od-xcoff.c (dump_xcoff32_symbols): Adapt to new
aux structures.
include/ChangeLog:
* coff/internal.h (union internal_auxent):
Add x_sect structure.
* coff/rs6000.h (union external_auxent): Rework to
match official documentation.
* coff/rs6k64.h (union external_auxent): Likewise.
(_AUX_SECT): New define.
PR 27760
include * coff/pe.h (IMAGE_DLLCHARACTERISTICS_APPCONTAINER): Define.
(IMAGE_DLLCHARACTERISTICS_GUARD_CF): Define.
bfd * peXXigen.c (_bfd_XX_print_private_bfd_data_common): Add display
of IMAGE_FILE_REMOVABLE_RUN_FROM_SWAP,
IMAGE_FILE_NET_RUN_FROM_SWAP and IMAGE_FILE_UP_SYSTEM_ONLY flags.
Decode the contents of the DllCharacteristics field.
So don't set those flags for an executable. In the patch I also test
DYNAMIC even though the PE bfd code doesn't appear to set it for dlls.
I figure it doesn't hurt to include that flag too.
PR 27567
bfd/
* coffcode.h (styp_to_sec_flags): Use an unsigned long styp_flags.
(coff_write_object_contents): Pass bfd to COFF_ENCODE_ALIGNMENT,
ignore alignment checks when return is false. Formatting.
include/
* coff/internal.h (struct internal_scnhdr): Make s_flags unsigned long.
* coff/pe.h (COFF_ENCODE_ALIGNMENT): Don't set align flags for an
executable and return false. Do so for a relocatable object and
evaluate to true.
* coff/ti.h (COFF_ENCODE_ALIGNMENT): Add bfd arg and evaluate to true.
(COFF_DECODE_ALIGNMENT): Formatting.
* coff/z80.h (COFF_ENCODE_ALIGNMENT): Similarly.
(COFF_DECODE_ALIGNMENT): Similarly.
This adds some annotation to Power10 pcrel instructions, displaying
the target address (ie. pc + D34 field) plus a symbol if there is one
at exactly that target address. pld from the .got or .plt will also
look up the entry and display it, symbolically if there is a dynamic
relocation on the entry.
include/
* dis-asm.h (struct disassemble_info): Add dynrelbuf and dynrelcount.
binutils/
* objdump.c (struct objdump_disasm_info): Delete dynrelbuf and
dynrelcount.
(find_symbol_for_address): Adjust for dynrelbuf and dynrelcount move.
(disassemble_section, disassemble_data): Likewise.
opcodes/
* ppc-dis.c (struct dis_private): Add "special".
(POWERPC_DIALECT): Delete. Replace uses with..
(private_data): ..this. New inline function.
(disassemble_init_powerpc): Init "special" names.
(skip_optional_operands): Add is_pcrel arg, set when detecting R
field of prefix instructions.
(bsearch_reloc, print_got_plt): New functions.
(print_insn_powerpc): For pcrel instructions, print target address
and symbol if known, and decode plt and got loads too.
gas/
* testsuite/gas/ppc/prefix-pcrel.d: Update expected output.
* testsuite/gas/ppc/prefix-reloc.d: Likewise.
* gas/testsuite/gas/ppc/vsx_32byte.d: Likewise.
ld/
* testsuite/ld-powerpc/inlinepcrel-1.d: Update expected output.
* testsuite/ld-powerpc/inlinepcrel-2.d: Likewise.
* testsuite/ld-powerpc/notoc2.d: Likewise.
* testsuite/ld-powerpc/notoc3.d: Likewise.
* testsuite/ld-powerpc/pcrelopt.d: Likewise.
* testsuite/ld-powerpc/startstop.d: Likewise.
* testsuite/ld-powerpc/tlsget.d: Likewise.
* testsuite/ld-powerpc/tlsget2.d: Likewise.
* testsuite/ld-powerpc/tlsld.d: Likewise.
* testsuite/ld-powerpc/weak1.d: Likewise.
* testsuite/ld-powerpc/weak1so.d: Likewise.
This turns into a signed left shift by 31 bits, otherwise. This is an
offset and is always treated as unsigned in any case, so add an
appropriate cast.
include/ChangeLog
2021-03-25 Nick Alcock <nick.alcock@oracle.com>
PR libctf/27628
* ctf-api.h: Fix some indentation.
(CTF_SET_STID): Always do an unsigned shift, even if STID is
signed.
AArch64 MTE support in the Linux kernel exposes a new register
through ptrace. This patch adds the required code to support it.
include/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* elf/common.h (NT_ARM_TAGGED_ADDR_CTRL): Define.
gdb/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* aarch64-linux-nat.c (fetch_mteregs_from_thread): New function.
(store_mteregs_to_thread): New function.
(aarch64_linux_nat_target::fetch_registers): Update to call
fetch_mteregs_from_thread.
(aarch64_linux_nat_target::store_registers): Update to call
store_mteregs_to_thread.
* aarch64-tdep.c (aarch64_mte_register_names): New struct.
(aarch64_cannot_store_register): Handle MTE registers.
(aarch64_gdbarch_init): Initialize and setup MTE registers.
* aarch64-tdep.h (gdbarch_tdep) <mte_reg_base>: New field.
<has_mte>: New method.
* arch/aarch64-linux.h (AARCH64_LINUX_SIZEOF_MTE): Define.
gdbserver/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* linux-aarch64-low.cc (aarch64_fill_mteregset): New function.
(aarch64_store_mteregset): New function.
(aarch64_regsets): Add MTE register set entry.
(aarch64_sve_regsets): Add MTE register set entry.
* peXXigen.c (_bfd_XXi_swap_aux_out): Avoid potential buffer
overrun by using sizeof of the destination x_fname field as the
limit for a memcpy.
* coff/internal.h (struct internal_auxent): Fix a couple of typos
in comment describing the x_fname field.
Add support for TLS in XCOFF. Amongst the things done by this commit:
- Update XCOFF auxialiary header to match new version and allow TLS
sections.
- Add TLS sections (.tdata and .tbss) support in gas and ld.
- Add support for the TLS relocations in gas and ld.
Two different types BFD_RELOC are created for PPC and PPC64 as
the size is a pointer, thus distinct in 32 or 64bit.
The addresses given by ld to .tdata and .tbss is a bit special. In
XCOFF, these addresses are actually offsets from the TLS pointer
computed at runtime. AIX assembly and linker does the same. In
top of that, the .tdata must be before .data (this is mandatory for AIX
loader). Thus, the aix ld script is recomputing "." before .data to restore
its original value. There might be a simpler way, but this one is working.
Optimisation linked to TLS relocations aren't yet implemented.
bfd/
* reloc.c (BFD_RELOC_PPC_TLS_LE, BFD_RELOC_PPC_TLS_IE,
BFD_RELOC_PPC_TLS_M, BFD_RELOC_PPC_TLS_ML, BFD_RELOC_PPC64_TLS_GD,
BFD_RELOC_PPC64_TLS_LD, BFD_RELOC_PPC64_TLS_LE,
BFD_RELOC_PPC64_TLS_IE, BFD_RELOC_PPC64_TLS_M,
BFD_RELOC_PPC64_TLS_ML): New relocations.
* bfd-in2.h: Regenerate.
* libbfd.h: Regenerate.
* coff-rs6000.c (xcoff_calculate_relocation): Call
xcoff_reloc_type_tls for TLS relocations.
(xcoff_howto_table): Implement TLS relocations.
(_bfd_xcoff_reloc_type_lookup): Add cases TLS relocations.
(xcoff_reloc_type_tls): New function.
* coff64-rs6000.c (xcoff_calculate_relocation): Likewise.
(xcoff_howto_table): Likewise.
(_bfd_xcoff_reloc_type_lookup): Likewise.
* coffcode.h (sec_to_styp_flags): Handle TLS sections.
(styp_to_sec_flags): Likewise.
(coff_compute_section_file_positions): Avoid file offset
optimisation for .data when the previous section is .tdata.
(coff_write_object_contents): Handle TLS sections.
* coffswap.h (coff_swap_aouthdr_out): Add support for
new fields in aouthdr.
* libxcoff.h (xcoff_reloc_type_tls): Add prototype.
* xcofflink.c (xcoff_link_add_symbols): Handle XMC_UL.
(xcoff_need_ldrel_p): Add cases for TLS relocations.
(xcoff_create_ldrel): Add l_symndx for TLS sections.
gas/
* config/tc-ppc.c (ppc_xcoff_text_section, ppc_xcoff_data_section,
(ppc_xcoff_bss_section, ppc_xcoff_tdata_section,
(ppc_xcoff_tbss_section): New variables.
(ppc_text_subsegment, ppc_text_csects, ppc_data_subgments,
(ppc_data_csects): Removed.
(ppc_xcoff_section_is_initialized, ppc_init_xcoff_section,
ppc_xcoff_parse_cons): New functions.
(md_being): Initialize XCOFF sections.
(ppc_xcoff_suffix): Add support for TLS relocations
(fixup_size, md_apply_fix): Add support for new BFD_RELOC.
(ppc_change_csect): Handle XMC_TL, XMC_UL. Correctly, add XMC_BS
to .bss section. Handle new XCOFF section variables.
(ppc_comm): Likewise.
(ppc_toc): Likewise.
(ppc_symbol_new_hook): Likewise.
(ppc_frob_symbol): Likewise.
(ppc_fix_adjustable): Add tbss support.
* config/tc-ppc.h (TC_PARSE_CONS_EXPRESSION): New define.
(ppc_xcoff_parse_cons): Add prototype.
(struct ppc_xcoff_section): New structure.
ld/
* emultempl/aix.em: Ensure .tdata section is removed
if empty, even with -r flag.
* scripttempl/aix.sc: Handle TLS sections.
* testsuite/ld-powerpc/aix52.exp: Add new tests.
* testsuite/ld-powerpc/aix-tls-reloc-32.d: New test.
* testsuite/ld-powerpc/aix-tls-reloc-64.d: New test.
* testsuite/ld-powerpc/aix-tls-reloc.ex: New test.
* testsuite/ld-powerpc/aix-tls-reloc.s: New test.
* testsuite/ld-powerpc/aix-tls-section-32.d: New test.
* testsuite/ld-powerpc/aix-tls-section-64.d: New test.
* testsuite/ld-powerpc/aix-tls-section.ex: New test.
* testsuite/ld-powerpc/aix-tls-section.s: New test.
include/
* coff/internal.h (struct internal_aouthdr): Add new fields.
* coff/rs6000.h (AOUTHDRÃ): Add new fields.
* coff/rs6k64.h (struct external_filehdr): Likewise.
* coff/xcoff.h (_TDATA), _TBSS): New defines
(RS6K_AOUTHDR_TLS_LE, RS6K_AOUTHDR_RAS, RS6K_AOUTHDR_ALGNTDATA,
RS6K_AOUTHDR_SHR_SYMTAB, RS6K_AOUTHDR_FORK_POLICY,
RS6K_AOUTHDR_FORK_COR): New defines.
(XMC_TU): Removed.
(XMC_UL): New define.
Since the last time AIX HOWTO table was modified, IBM has now
released an official documentation about XCOFF relocations.
This commit corrects the wrong ones and add some missing.
For now, the "custom" relocations made for xcoff_rtype2howto have
been kept.
The new relocations are still set as EMPTY_HOWTO because they will
be implemented in later commits.
In xcoff[64]_ppc_relocate_section, instead of recreating howto
from scratch, it's better to use the existing howto from the
table and fixing it according to r_size field.
bfd/
* coff-rs6000.c (xcoff_calculate_relocation): Correct and
add new relocations.
(xcoff_howto_table): Likewise.
(xcoff_rtype2howto): Increase r_type maximum value.
(xcoff_ppc_relocate_section): Reuse predefined HOWTOs instead
of create a new one from scratch. Enable only some relocations
to have a changing r_size.
* coff64-rs6000.c (xcoff64_calculate_relocation): Likewise.
(xcoff64_howto_table): Likewise.
(xcoff64_rtype2howto): Likewise.
(xcoff64_ppc_relocate_section): Likewise.
* libxcoff.h (XCOFF_MAX_CALCULATE_RELOCATION): Fix value.
binutils/
* od-xcoff.c: Replace RTB by TRL entry.
include/
* coff/xcoff.h (R_RTB): Remove.
(R_TRL): Fix value.
Adds support for including RISC-V control and status registers into
core files.
The value for the define NT_RISCV_CSR is set to 0x900, this
corresponds to a patch I have proposed for the Linux kernel here:
http://lists.infradead.org/pipermail/linux-riscv/2020-December/003910.html
As I have not yet heard if the above patch will be accepted into the
kernel or not I have set the note name string to "GDB", and the note
type to NT_RISCV_CSR.
This means that if the above patch is rejected from the kernel, and
the note type number 0x900 is assigned to some other note type, we
will still be able to distinguish between the GDB produced
NT_RISCV_CSR, and the kernel produced notes, where the name would be
set to "CORE".
bfd/ChangeLog:
* elf-bfd.h (elfcore_write_riscv_csr): Declare.
* elf.c (elfcore_grok_riscv_csr): New function.
(elfcore_grok_note): Handle NT_RISCV_CSR.
(elfcore_write_riscv_csr): New function.
(elfcore_write_register_note): Handle '.reg-riscv-csr'.
binutils/ChangeLog:
* readelf.c (get_note_type): Handle NT_RISCV_CSR.
include/ChangeLog:
* elf/common.h (NT_RISCV_CSR): Define.
This commit lays the ground work for allowing GDB to write its target
description into a generated core file.
The goal of this work is to allow a user to connect to a remote
target, capture a core file from within GDB, then pass the executable
and core file to another user and have the user be able to examine the
state of the machine without needing to connect to a running target.
Different remote targets can have different register sets and this
information is communicated from the target to GDB in the target
description.
It is possible for a user to extract the target description from GDB
and pass this along with the core file so that when the core file is
used the target description can be fed back into GDB, however this is
not a great user experience.
It would be nicer, I think, if GDB could write the target description
directly into the core file, and then make use of this description
when loading a core file.
This commit performs the binutils/bfd side of this task, adding the
boiler plate functions to access the target description from within a
core file note, and reserving a new number for a note containing the
target description. Later commits will extend GDB to make use of
this.
The new note is given the name 'GDB' and a type NT_GDB_TDESC. This
should hopefully protect us if there's ever a reuse of the number
assigned to NT_GDB_TDESC by some other core file producer. It should
also, hopefully, make it clearer to users that this note carries GDB
specific information.
bfd/ChangeLog:
* elf-bfd.h (elfcore_write_gdb_tdesc): Declare new function.
* elf.c (elfcore_grok_gdb_tdesc): New function.
(elfcore_grok_note): Handle NT_GDB_TDESC.
(elfcore_write_gdb_tdesc): New function.
(elfcore_write_register_note): Handle NT_GDB_TDESC.
binutils/ChangeLog:
* readelf.c (get_note_type): Handle NT_GDB_TDESC.
include/ChangeLog:
* elf/common.h (NT_GDB_TDESC): Define.
The nondeduplicating CTF linker was kept around when the deduplicating
one was added so that people had something to fall back to in case the
deduplicating linker turned out to be buggy. It's now much more stable
than the nondeduplicating linker, in addition to much faster, using much
less memory and producing much better output. In addition, while
libctf has a linker flag to invoke the nondeduplicating linker, ld does
not expose it: the only way to turn it on within ld is an intentionally-
undocumented environment variable. So we can remove it without any ABI
or user-visibility concerns (the only thing we leave around is the
CTF_LINK_NONDEDUP flag, which can easily be interpreted as "deduplicate
less", though right now it does nothing).
This lets us remove a lot of complexity associated with tracking
filenames and CU names separately (something the deduplcating linker
never bothered with, since the cunames are always reliable and ld never
hands us useful filenames anyway)
The biggest lacuna left behind is the ctf_type_mapping machinery, which
slows down deduplicating links quite a lot. We can't just ditch it
because ctf_add_type uses it: removing the slowdown from the
deduplicating linker is a job for another commit.
include/ChangeLog
2021-03-02 Nick Alcock <nick.alcock@oracle.com>
* ctf-api.h (CTF_LINK_SHARE_DUPLICATED): Note that this might
merely change how much deduplication is done.
libctf/ChangeLog
2021-03-02 Nick Alcock <nick.alcock@oracle.com>
* ctf-link.c (ctf_create_per_cu): Drop FILENAME now that it is
always identical to CUNAME.
(ctf_link_deduplicating_one_symtypetab): Adjust.
(ctf_link_one_type): Remove.
(ctf_link_one_input_archive_member): Likewise.
(ctf_link_close_one_input_archive): Likewise.
(ctf_link_one_input_archive): Likewise.
(ctf_link): No longer call it. Drop CTF_LINK_NONDEDUP path.
Improve header comment a bit (dicts, not files). Adjust
ctf_create_per_cu call.
(ctf_link_deduplicating_variables): Simplify.
(ctf_link_in_member_cb_arg_t) <cu_name>: Remove.
<in_input_cu_file>: Likewise.
<in_fp_parent>: Likewise.
<done_parent>: Likewise.
(ctf_link_one_variable): Turn uses of in_file_name to in_cuname.
When --gc-sections is in effect, a reference from a retained section
to __start_SECNAME or __stop_SECNAME causes all input sections named
SECNAME to also be retained, if SECNAME is representable as a C
identifier and either __start_SECNAME or __stop_SECNAME is synthesized
by the linker. Add an option to disable that feature, effectively
ignoring any relocation that references a synthesized linker defined
__start_ or __stop_ symbol.
PR 27451
include/
* bfdlink.h (struct bfd_link_info): Add start_stop_gc.
bfd/
* elflink.c (_bfd_elf_gc_mark_rsec): Ignore synthesized linker
defined start/stop symbols when start_stop_gc.
(bfd_elf_gc_mark_dynamic_ref_symbol): Likewise.
(bfd_elf_define_start_stop): Don't modify ldscript_def syms.
* linker.c (bfd_generic_define_start_stop): Likewise.
ld/
* emultempl/elf.em: Handle -z start-stop-gc and -z nostart-stop-gc.
* lexsup.c (elf_static_list_options): Display help for them. Move
help for -z stack-size to here from elf_shlib_list_options. Add
help for -z start-stop-visibility and -z undefs.
* ld.texi: Document -z start-stop-gc and -z nostart-stop-gc.
* NEWS: Mention -z start-stop-gc.
* testsuite/ld-gc/start2.s,
* testsuite/ld-gc/start2.d: New test.
* testsuite/ld-gc/gc.exp: Run it.
Note that we don't even warn if scripts adjust a symbol as in
ld-elf/var1 and ld-scripts/pr14962.
include/
* bfdlink.h (struct bfd_link_info): Add warn_multiple_definition.
ld/
* ldexp.c (exp_fold_tree_1): Warn on script defining a symbol
defined in an object file.
* ldmain.c (multiple_definition): Heed info->warn_multiple_definition.
* testsuite/ld-scripts/defined5.d: Expect a warning.
The existing ctf_lookup_by_symbol and ctf_arc_lookup_symbol functions
suffice to look up the types of symbols if the caller already has a
symbol number. But the caller often doesn't have one of those and only
knows the name of the symbol: also, in object files, the caller might
not have a useful symbol number in any sense (and neither does libctf:
the 'symbol number' we use in that case literally starts at 0 for the
lexicographically first-sorted symbol in the symtypetab and counts those
symbols, so it corresponds to nothing useful).
This means that even though object files have a symtypetab (generated by
the compiler or by ld -r), the only way we can look up anything in it is
to iterate over all symbols in turn with ctf_symbol_next until we find
the one we want.
This is unhelpful and pointlessly inefficient.
So add a pair of functions to look up symbols by name in a dict and in a
whole archive: ctf_lookup_by_symbol_name and ctf_arc_lookup_symbol_name.
These are identical to the existing functions except that they take
symbol names rather than symbol numbers.
To avoid insane repetition, we do some refactoring in the process, so
that both ctf_lookup_by_symbol and ctf_arc_lookup_symbol turn into thin
wrappers around internal functions that do both lookup by symbol index
and lookup by name. This massively reduces code duplication because
even the existing lookup-by-index stuff wants to use a name sometimes
(when looking up in indexed sections), and the new lookup-by-name stuff
has to turn it into an index sometimes (when looking up in non-indexed
sections): doing it this way lets us share most of that.
The actual name->index lookup is done by ctf_lookup_symbol_idx. We do
not anticipate this lookup to be as heavily used as ld.so symbol lookup
by many orders of magnitude, so using the ELF symbol hashes would
probably take more time to read them than is saved by using the hashes,
and it adds a lot of complexity. Instead, do a linear search for the
symbol name, caching all the name -> index mappings as we go, so that
future searches are likely to hit in the cache. To avoid having to
repeat this search over and over in a CTF archive when
ctf_arc_lookup_symbol_name is used, have cached archive lookups (the
sort done by ctf_arc_lookup_symbol* and the ctf_archive_next iterator)
pick out the first dict they cache in a given archive and store it in a
new ctf_archive field, ctfi_crossdict_cache. This can be used to store
cross-dictionary cached state that depends on things like the ELF symbol
table rather than the contents of any one dict. ctf_lookup_symbol_idx
then caches its name->index mappings in the dictionary named in the
crossdict cache, if any, so that ctf_lookup_symbol_idx in other dicts
in the same archive benefit from the previous linear search, and the
symtab only needs to be scanned at most once.
(Note that if you call ctf_lookup_by_symbol_name in one specific dict,
and then follow it with a ctf_arc_lookup_symbol_name, the former will
not use the crossdict cache because it's only populated by the dict
opens in ctf_arc_lookup_symbol_name. This is harmless except for a small
one-off waste of memory and time: it's only a cache, after all. We can
fix this later by using the archive caching machinery more
aggressively.)
In ctf-archive, we do similar things, turning ctf_arc_lookup_symbol into
a wrapper around a new function that does both index -> ID and name ->
ID lookups across all dicts in an archive. We add a new
ctfi_symnamedicts cache that maps symbol names to the ctf_dict_t * that
it was found in (so that linear searches for symbols don't need to be
repeated): but we also *remove* a cache, the ctfi_syms cache that was
memoizing the actual ctf_id_t returned from every call to
ctf_arc_lookup_symbol. This is pointless: all it saves is one call to
ctf_lookup_by_symbol, and that's basically an array lookup and nothing
more so isn't worth caching. (Equally, given that symbol -> index
mappings are cached by ctf_lookup_by_symbol_name, those calls are nearly
free after the first call, so there's no point caching the ctf_id_t in
that case either.)
We fix up one test that was doing manual symbol lookup to use
ctf_arc_lookup_symbol instead, and enhance it to check that the caching
layer is not totally broken: we also add a new test to do lookups in a
.o file, and another to do lookups in an archive with conflicted types
and make sure that sort of multi-dict lookup is actually working.
include/ChangeLog
2021-02-17 Nick Alcock <nick.alcock@oracle.com>
* ctf-api.h (ctf_arc_lookup_symbol_name): New.
(ctf_lookup_by_symbol_name): Likewise.
libctf/ChangeLog
2021-02-17 Nick Alcock <nick.alcock@oracle.com>
* ctf-impl.h (ctf_dict_t) <ctf_symhash>: New.
<ctf_symhash_latest>: Likewise.
(struct ctf_archive_internal) <ctfi_crossdict_cache>: New.
<ctfi_symnamedicts>: New.
<ctfi_syms>: Remove.
(ctf_lookup_symbol_name): Remove.
* ctf-lookup.c (ctf_lookup_symbol_name): Propagate errors from
parent properly. Make static.
(ctf_lookup_symbol_idx): New, linear search for the symbol name,
cached in the crossdict cache's ctf_symhash (if available), or
this dict's (otherwise).
(ctf_try_lookup_indexed): Allow the symname to be passed in.
(ctf_lookup_by_symbol): Turn into a wrapper around...
(ctf_lookup_by_sym_or_name): ... this, supporting name lookup too,
using ctf_lookup_symbol_idx in non-writable dicts. Special-case
name lookup in dynamic dicts without reported symbols, which have
no symtab or dynsymidx but where name lookup should still work.
(ctf_lookup_by_symbol_name): New, another wrapper.
* ctf-archive.c (enosym): Note that this is present in
ctfi_symnamedicts too.
(ctf_arc_close): Adjust for removal of ctfi_syms. Free the
ctfi_symnamedicts.
(ctf_arc_flush_caches): Likewise.
(ctf_dict_open_cached): Memoize the first cached dict in the
crossdict cache.
(ctf_arc_lookup_symbol): Turn into a wrapper around...
(ctf_arc_lookup_sym_or_name): ... this. No longer cache
ctf_id_t lookups: just call ctf_lookup_by_symbol as needed (but
still cache the dicts those lookups succeed in). Add
lookup-by-name support, with dicts of successful lookups cached in
ctfi_symnamedicts. Refactor the caching code a bit.
(ctf_arc_lookup_symbol_name): New, another wrapper.
* ctf-open.c (ctf_dict_close): Free the ctf_symhash.
* libctf.ver (LIBCTF_1.2): New version. Add
ctf_lookup_by_symbol_name, ctf_arc_lookup_symbol_name.
* testsuite/libctf-lookup/enum-symbol.c (main): Use
ctf_arc_lookup_symbol rather than looking up the name ourselves.
Fish it out repeatedly, to make sure that symbol caching isn't
broken.
(symidx_64): Remove.
(symidx_32): Remove.
* testsuite/libctf-lookup/enum-symbol-obj.lk: Test symbol lookup
in an unlinked object file (indexed symtypetab sections only).
* testsuite/libctf-writable/symtypetab-nonlinker-writeout.c
(try_maybe_reporting): Check symbol types via
ctf_lookup_by_symbol_name as well as ctf_symbol_next.
* testsuite/libctf-lookup/conflicting-type-syms.*: New test of
lookups in a multi-dict archive.
Make the opcode/riscv-opc.c and include/opcode/riscv.h tidy, move the
spec versions stuff to bfd/cpu-riscv.h. Also move the csr stuff and
ext_version_table to gas/config/tc-riscv.c for internal use. To avoid
too many repeated code, define general RISCV_GET_SPEC_NAME/SPEC_CLASS
macros. Therefore, assembler/dis-assembler/linker/gdb can get all spec
versions related stuff from cpu-riscv.h and cpu-riscv.c, since the stuff
are defined there uniformly.
bfd/
* Makefile.am: Added cpu-riscv.h.
* Makefile.in: Regenerated.
* po/SRC-POTFILES.in: Regenerated.
* cpu-riscv.h: Added to support spec versions controlling.
Also added extern arrays and functions for cpu-riscv.c.
(enum riscv_spec_class): Define all spec classes here uniformly.
(struct riscv_spec): Added for all specs.
(RISCV_GET_SPEC_CLASS): Added to reduce repeated code.
(RISCV_GET_SPEC_NAME): Likewise.
(RISCV_GET_ISA_SPEC_CLASS): Added to get ISA spec class.
(RISCV_GET_PRIV_SPEC_CLASS): Added to get privileged spec class.
(RISCV_GET_PRIV_SPEC_NAME): Added to get privileged spec name.
* cpu-riscv.c (struct priv_spec_t): Replaced with struct riscv_spec.
(riscv_get_priv_spec_class): Replaced with RISCV_GET_PRIV_SPEC_CLASS.
(riscv_get_priv_spec_name): Replaced with RISCV_GET_PRIV_SPEC_NAME.
(riscv_priv_specs): Moved below.
(riscv_get_priv_spec_class_from_numbers): Likewise, updated.
(riscv_isa_specs): Moved from include/opcode/riscv.h.
* elfnn-riscv.c: Included cpu-riscv.h.
(riscv_merge_attributes): Initialize in_priv_spec and out_priv_spec.
* elfxx-riscv.c: Included cpu-riscv.h and opcode/riscv.h.
(RISCV_UNKNOWN_VERSION): Moved from include/opcode/riscv.h.
* elfxx-riscv.h: Removed extern functions to cpu-riscv.h.
gas/
* config/tc-riscv.c: Included cpu-riscv.h.
(enum riscv_csr_clas): Moved from include/opcode/riscv.h.
(struct riscv_csr_extra): Likewise.
(struct riscv_ext_version): Likewise.
(ext_version_table): Moved from opcodes/riscv-opc.c.
(default_isa_spec): Updated type to riscv_spec_class.
(default_priv_spec): Likewise.
(riscv_set_default_isa_spec): Updated.
(init_ext_version_hash): Likewise.
(riscv_init_csr_hash): Likewise, also fixed indent.
include/
* opcode/riscv.h: Moved stuff and make the file tidy.
opcodes/
* riscv-dis.c: Included cpu-riscv.h, and removed elfxx-riscv.h.
(default_priv_spec): Updated type to riscv_spec_class.
(parse_riscv_dis_option): Updated.
* riscv-opc.c: Moved stuff and make the file tidy.
opcodes/
* s390-mkopc.c (main): Accept arch14 as cpu string.
* s390-opc.txt: Add new arch14 instructions.
include/
* opcode/s390.h (enum s390_opcode_cpu_val): Add
S390_OPCODE_ARCH14.
gas/
* config/tc-s390.c (s390_parse_cpu): New entry for arch14.
* doc/c-s390.texi: Document arch14 march option.
* testsuite/gas/s390/s390.exp: Run the arch14 related tests.
* testsuite/gas/s390/zarch-arch14.d: New test.
* testsuite/gas/s390/zarch-arch14.s: New test.
Now that "anonymous typedef nodes" have been extirpated, we can mandate
that things that have names in C must have names in CTF too. (Unlike
the no-forwards embarrassment, the deduplicator does nothing special
with names: types that have names in C will have the same name in CTF.
So we can assume that the CTF rules and the C rules are the same.)
include/ChangeLog
2021-01-27 Nick Alcock <nick.alcock@oracle.com>
* ctf-api.h (ECTF_NONAME): New.
(ECTF_NERR): Adjust.
libctf/ChangeLog
2021-01-27 Nick Alcock <nick.alcock@oracle.com>
* ctf-create.c (ctf_add_encoded): Add check for non-empty name.
(ctf_add_forward): Likewise.
(ctf_add_typedef): Likewise.
The variable section in a CTF dict is meant to contain the types of
variables that do not appear in the symbol table (mostly file-scope
static declarations). We implement this by having the compiler emit
all potential data symbols into both sections, then delete those
symbols from the variable section that correspond to data symbols the
linker has reported.
Unfortunately, the check for this in ctf_serialize is wrong: rather than
checking the set of linker-reported symbols, we check the set of names
in the data object symtypetab section: if the linker has reported no
symbols at all (usually if ld -r has been run, or if a non-linker
program that does not use symbol tables is calling ctf_link) this will
include every single symbol, emptying the variable section completely.
Worse, when ld -r is in use, we want to force writeout of every
symtypetab entry on the inputs, in an indexed section, whether or not
the linker has reported them, since this isn't a final link yet and the
symbol table is not finalized (and may grow more symbols than the linker
has yet reported). But the check for this is flawed too: we were
relying on ctf_link_shuffle_syms not having been called if no symbols
exist, but that function is *always* called by ld even when ld -r is in
use: ctf_link_add_linker_symbol is the one that's not called when there
are no symbols.
We clearly need to rethink this. Using the emptiness of the set of
reported symbols as a test for ld -r is just ugly: the linker already
knows if ld -r is underway and can just tell us. So add a new linker
flag CTF_LINK_NO_FILTER_REPORTED_SYMS that is set to stop the linker
filtering the symbols in the symtypetab sections using the set that the
linker has reported: use the presence or absence of this flag to
determine whether to emit unindexed symtabs: we only remove entries from
the variable section when filtering symbols, and we only remove them if
they are in the reported symbol set, fixing the case where no symbols
are reported by the linker at all.
(The negative sense of the new CTF_LINK flag is intentional: the common
case, both for ld and for simple tools that want to do a ctf_link with
no ELF symbol table in sight, is probably to filter out symbols that no
linker has reported: i.e., for the simple tools, all of them.)
There's another wrinkle, though. It is quite possible for a non-linker
to add symbols to a dict via ctf_add_*_sym and then write it out via the
ctf_write APIs: perhaps it's preparing a dict for a later linker
invocation. Right now this would not lead to anything terribly
meaningful happening: ctf_serialize just assumes it was called via
ctf_link if symbols are present. So add an (internal-to-libctf) flag
that indicates that a writeout is happening via ctf_link_write, and set
it there (propagating it to child dicts as needed). ctf_serialize can
then spot when it is not being called by a linker, and arrange to always
write out an indexed, sorted symtypetab for fastest possible future
symbol lookup by name in that case. (The writeouts done by ld -r are
unsorted, because the only thing likely to use those symtabs is the
linker, which doesn't benefit from symtypetab sorting.)
Tests added for all three linking cases (ld -r, ld -shared, ld), with a
bit of testsuite framework enhancement to stop it unconditionally
linking the CTF to be checked by the lookup program with -shared, so
tests can now examine CTF linked with -r or indeed with no flags at all,
though the output filename is still foo.so even in this case.
Another test added for the non-linker case that endeavours to determine
whether the symtypetab is sorted by examining the order of entries
returned from ctf_symbol_next: nobody outside libctf should rely on
this ordering, but this test is not outside libctf :)
include/ChangeLog
2021-01-26 Nick Alcock <nick.alcock@oracle.com>
* ctf-api.h (CTF_LINK_NO_FILTER_REPORTED_SYMS): New.
ld/ChangeLog
2021-01-26 Nick Alcock <nick.alcock@oracle.com>
* ldlang.c (lang_merge_ctf): Set CTF_LINK_NO_FILTER_REPORTED_SYMS
when appropriate.
libctf/ChangeLog
2021-01-27 Nick Alcock <nick.alcock@oracle.com>
* ctf-impl.c (_libctf_nonnull_): Add parameters.
(LCTF_LINKING): New flag.
(ctf_dict_t) <ctf_link_flags>: Mention it.
* ctf-link.c (ctf_link): Keep LCTF_LINKING set across call.
(ctf_write): Likewise, including in child dictionaries.
(ctf_link_shuffle_syms): Make sure ctf_dynsyms is NULL if there
are no reported symbols.
* ctf-create.c (symtypetab_delete_nonstatic_vars): Make sure
the variable has been reported as a symbol by the linker.
(symtypetab_skippable): Mention relationship between SYMFP and the
flags.
(symtypetab_density): Adjust nonnullity. Exit early if no symbols
were reported and force-indexing is off (i.e., we are doing a
final link).
(ctf_serialize): Handle the !LCTF_LINKING case by writing out an
indexed, sorted symtypetab (and allow SYMFP to be NULL in this
case). Turn sorting off if this is a non-final link. Only delete
nonstatic vars if we are filtering symbols and the linker has
reported some.
* testsuite/libctf-regression/nonstatic-var-section-ld-r*:
New test of variable and symtypetab section population when
ld -r is used.
* testsuite/libctf-regression/nonstatic-var-section-ld-executable.lk:
Likewise, when ld of an executable is used.
* testsuite/libctf-regression/nonstatic-var-section-ld.lk:
Likewise, when ld -shared alone is used.
* testsuite/libctf-regression/nonstatic-var-section-ld*.c:
Lookup programs for the above.
* testsuite/libctf-writable/symtypetab-nonlinker-writeout.*: New
test, testing survival of symbols across ctf_write paths.
* testsuite/lib/ctf-lib.exp (run_lookup_test): New option,
nonshared, suppressing linking of the SOURCE with -shared.
bfd/
* elfnn-riscv.c: Indent, labels and GNU coding standards tidy,
also aligned the code.
gas/
* config/tc-riscv.c: Indent and GNU coding standards tidy,
also aligned the code.
* config/tc-riscv.h: Likewise.
include/
* opcode/riscv.h: Indent and GNU coding standards tidy,
also aligned the code.
opcodes/
* riscv-opc.c (riscv_gpr_names_abi): Aligned the code.
(riscv_fpr_names_abi): Likewise.
(riscv_opcodes): Likewise.
(riscv_insn_types): Likewise.
