PR/32298 sframe: no SFrame stack trace info generated for .plt.got
Add support to generate SFrame stack trace info for .plt.got section.
Enhance the current definition of struct elf_x86_sframe_plt to include
initialized SFrame FDE/FREs applicable for .plt.got section. There are
two variants of .plt.got entries: 16 byte and 8 byte.
8 byte:
ff 25 00 00 00 00 jmpq *name@GOTPCREL(%rip)
66 90 xchg %ax,%ax
16 byte:
f3 0f 1e fa endbr64
ff 25 66 2f 00 00 jmpq *name@GOTPCREL(%rip)
66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1)
For the testcase, define some application symbols such that their PLT
entry is placed in .plt.got and ensure SFrame information is generated
with and without -z ibtplt.
ChangeLog:
PR/32298
* bfd/elf64-x86-64.c (elf_x86_64_link_setup_gnu_properties):
PLT GOT entry size is different for IBT vs non IBT PLTs.
* bfd/elfxx-x86.c (enum dynobj_sframe_plt_type): New enum for
SFRAME_PLT_GOT.
(_bfd_x86_elf_create_sframe_plt): Handle SFRAME_PLT_GOT.
(_bfd_x86_elf_write_sframe_plt): Likewise.
(_bfd_x86_elf_late_size_sections): Likewise.
(_bfd_x86_elf_finish_dynamic_sections): Likewise.
* bfd/elfxx-x86.h (struct elf_x86_sframe_plt): Add new members
to keep information about PLT GOT entries.
(struct elf_x86_link_hash_table): Add support for creating
SFrame section for .plt.got.
* ld/testsuite/ld-x86-64/x86-64.exp: Add new tests.
* ld/testsuite/ld-x86-64/sframe-pltgot-1.d: New test.
* ld/testsuite/ld-x86-64/sframe-pltgot-1.s: New test.
* ld/testsuite/ld-x86-64/sframe-pltgot-2.d: New test.
Fix PR/32296 sframe: wrong SFrame info for pltN and .plt.sec for -z ibtplt
The x86 psABI defines a 2-PLT scheme for IBT which uses .plt and
.plt.sec entries. It was observed that SFrame information for .plt.sec
section was incorrect. The erroneous assumption was that SFrame stack
trace information for .plt.sec with lazy binding is the same as SFrame
stack trace information for .plt with lazy binding. This is corrected
now by initializing a new SFrame PLT helper object
elf_x86_64_sframe_ibt_plt for lazy PLT with IBT.
Add a testcase where linking with -z ibtplt generates .plt.sec entries and
ensure correct SFrame information for it.
Committed by Indu Bhagat.
ChangeLog:
PR/32296
* bfd/elf64-x86-64.c (elf_x86_64_sframe_ibt_pltn_fre2): New
definition elf_x86_64_sframe_ibt_plt. Use it in
elf_x86_64_sframe_plt.
(elf_x86_64_link_setup_gnu_properties): Lazy IBT PLT entries are
different from lazy PLT.
* bfd/elfxx-x86.c (_bfd_x86_elf_create_sframe_plt): Adjust for
SFrame for IBT PLT.
* ld/testsuite/ld-x86-64/x86-64.exp: Add new test.
* ld/testsuite/ld-x86-64/sframe-ibt-plt-1.d: New test.
When _creating_ SFrame information for the linker created .plt.sec, the
code correctly checks for presence of .plt.sec. When _writing_ the
SFrame section for the corresponding .plt.sec, however, the conditionals
were wrongly checking for splt. This was causing an assertion at link
time.
This issue has been known to affect glibc build with SFrame enabled.
No testcase is added just yet. A later commit ensures correct SFrame
stack trace information is created for .plt.got. A test case (where only
.plt and .plt.got are created) is added then.
PR/32297 sframe: bfd assertion with empty main on IBT enabled system
Committed by Indu Bhagat.
ChangeLog:
PR/32297
* bfd/elfxx-x86.c (_bfd_x86_elf_late_size_sections): Check for
plt_second member not for splt.
Given that relocation symbol name can now be NULL for ELF, adjust
various get_synthetic_symtab routines so they don't segfault.
* elf.c (_bfd_elf_get_synthetic_symtab): Cope with sym->name
possibly being NULL.
* elf32-arm.c (elf32_arm_get_synthetic_symtab): Likewise.
* elf32-ppc.c (ppc_elf_get_synthetic_symtab): Likewise.
* elf64-ppc.c (ppc64_elf_get_synthetic_symtab): Likewise.
* elfxx-mips.c (_bfd_mips_elf_get_synthetic_symtab): Likewise.
* elfxx-x86.c (_bfd_x86_elf_get_synthetic_symtab): Likewise.
Since R_386_TLS_DESC_CALL can only be used with
call *variable@TLSCALL(%eax)
and R_X86_64_TLSDESC_CALL can only be used with
call *variable@TLSCALL(%rax)
update TLS transition error report to display the expected register in
indirect CALL.
bfd/
PR ld/32017
* elfxx-x86.c (_bfd_x86_elf_link_hash_table_create): Initialize
the ax_register field.
(_bfd_x86_elf_link_report_tls_transition_error): Report the
expected register in elf_x86_tls_error_indirect_call error.
* elfxx-x86.h (elf_x86_link_hash_table): Add ax_register.
ld/
PR ld/32017
* testsuite/ld-i386/tlsgdesc2.d: Updated.
* testsuite/ld-i386/tlsgdesc2.s: Change jmp to call via ECX.
* testsuite/ld-x86-64/tlsdesc4.d: Updated.
* testsuite/ld-x86-64/tlsdesc4.s: Change jmp to call via RCX.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Change TLS transition error messages from
a-argp-help.o(.text+0x12f): relocation R_X86_64_GOTTPOFF against `a' must be used in ADD or MOV onlyld: final link failed: bad value
to
a-argp-help.o(.text+0x12f): relocation R_X86_64_GOTTPOFF against `a' must be used in ADD or MOV only
ld: final link failed: bad value
PR ld/32017
* elfxx-x86.c (_bfd_x86_elf_link_report_tls_transition_error):
Add missing newlines.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Normally, the section contents is allocated by bfd_alloc which is freed
when the object is closed. But the .dynamic section contents is allocated
by bfd_realloc, which should be freed by calling free. Add a dynamic
field to elf_link_hash_table for the .dynamic section and free its
contents in _bfd_elf_link_hash_table_free.
* elf-bfd.h (elf_link_hash_table): Add dynamic.
* elflink.c (_bfd_elf_link_create_dynamic_sections): Set the
dynamic field in elf_link_hash_table.
(_bfd_elf_add_dynamic_entry): Use hash_table->dynamic.
(_bfd_elf_strip_zero_sized_dynamic_sections): Likewise.
(bfd_elf_add_dt_needed_tag): Likewise.
(elf_finalize_dynstr): Likewise.
(_bfd_elf_link_hash_table_free): Free htab->dynamic->contents.
(bfd_elf_final_link): Use htab->dynamic.
* elfxx-x86.c (_bfd_x86_elf_finish_dynamic_sections): Use
htab->elf.dynamic.
This largely mechanical patch is preparation for a followup patch.
For quite some time I've thought that it would be useful to call
elf_backend_size_dynamic_sections even when no dynamic objects are
seen by the linker. That's what this patch does, with some renaming.
There are no functional changes to the linker, just a move of the
dynobj test in bfd_elf_size_dynamic_sections to target backend
functions, replacing the asserts/aborts already there. No doubt some
of the current always_size_sections functions could be moved to
size_dynamic_sections but I haven't made that change.
Because both hooks are now always called, I have renamed
always_size_sections to early_size_sections and size_dynamic_sections
to late_size_sections. I condisdered calling late_size_sections plain
size_sections, since this is the usual target dynamic section sizing
hook, but decided that searching the sources for "size_sections" would
then hit early_size_sections and other functions.
Adds two new external authors to etc/update-copyright.py to cover
bfd/ax_tls.m4, and adds gprofng to dirs handled automatically, then
updates copyright messages as follows:
1) Update cgen/utils.scm emitted copyrights.
2) Run "etc/update-copyright.py --this-year" with an extra external
author I haven't committed, 'Kalray SA.', to cover gas testsuite
files (which should have their copyright message removed).
3) Build with --enable-maintainer-mode --enable-cgen-maint=yes.
4) Check out */po/*.pot which we don't update frequently.
The PLT entry in executables and shared libraries contains an indirect
branch, like
jmp *foo@GOTPCREL(%rip)
push $index_foo
jmp .PLT0
or
endbr64
jmp *foo@GOTPCREL(%rip)
NOP padding
which is used to branch to the function, foo, defined in another object.
Each R_X86_64_JUMP_SLOT relocation has a corresponding PLT entry.
The dynamic tags have been added to the x86-64 psABI to mark such PLT
entries:
6d824a52a4
Add an x86-64 linker option, -z mark-plt, to mark PLT entries with
#define DT_X86_64_PLT (DT_LOPROC + 0)
#define DT_X86_64_PLTSZ (DT_LOPROC + 1)
#define DT_X86_64_PLTENT (DT_LOPROC + 3)
1. DT_X86_64_PLT: The address of the procedure linkage table.
2. DT_X86_64_PLTSZ: The total size, in bytes, of the procedure linkage
table.
3. DT_X86_64_PLTENT: The size, in bytes, of a procedure linkage table
entry.
and set the r_addend field of the R_X86_64_JUMP_SLOT relocation to the
memory offset of the indirect branch instruction. The dynamic linker
can use these tags to update the PLT section to direct branch.
bfd/
* elf-linker-x86.h (elf_linker_x86_params): Add mark_plt.
* elf64-x86-64.c (elf_x86_64_finish_dynamic_symbol): Set the
r_addend of R_X86_64_JUMP_SLOT to the indirect branch offset
in PLT entry for -z mark-plt.
* elfxx-x86.c (_bfd_x86_elf_size_dynamic_sections): Add
DT_X86_64_PLT, DT_X86_64_PLTSZ and DT_X86_64_PLTENT for
-z mark-plt.
(_bfd_x86_elf_finish_dynamic_sections): Set DT_X86_64_PLT,
DT_X86_64_PLTSZ and DT_X86_64_PLTENT.
(_bfd_x86_elf_get_synthetic_symtab): Ignore addend for
JUMP_SLOT relocation.
(_bfd_x86_elf_link_setup_gnu_properties): Set
plt_indirect_branch_offset.
* elfxx-x86.h (elf_x86_plt_layout): Add plt_indirect_branch_offset.
binutils/
* readelf.c (get_x86_64_dynamic_type): New function.
(get_dynamic_type): Call get_x86_64_dynamic_type.
include/
* elf/x86-64.h (DT_X86_64_PLT): New.
(DT_X86_64_PLTSZ): Likewise.
(DT_X86_64_PLTENT): Likewise.
ld/
* ld.texi: Document -z mark-plt and -z nomark-plt.
* emulparams/elf32_x86_64.sh: Source x86-64-plt.sh.
* emulparams/elf_x86_64.sh: Likewise.
* emulparams/x86-64-plt.sh: New file.
* testsuite/ld-x86-64/mark-plt-1.s: Likewise.
* testsuite/ld-x86-64/mark-plt-1a-x32.d: Likewise.
* testsuite/ld-x86-64/mark-plt-1a.d: Likewise.
* testsuite/ld-x86-64/mark-plt-1b-x32.d: Likewise.
* testsuite/ld-x86-64/mark-plt-1b.d: Likewise.
* testsuite/ld-x86-64/mark-plt-1c-x32.d: Likewise.
* testsuite/ld-x86-64/mark-plt-1c.d: Likewise.
* testsuite/ld-x86-64/mark-plt-1d-x32.d: Likewise.
* testsuite/ld-x86-64/mark-plt-1d.d: Likewise.
* testsuite/ld-x86-64/x86-64.exp: Run -z mark-plt tests.
If a linker script does not place the PLT relocations and "normal"
relocations in separate ELF sections, `ld` will currently output incorrect
values for DT_JMPREL and DT_PLTRELSZ - they cover the entire ELF section,
rather than just the PLT relocations
Don't ignore the extent of the BFD section - use the size of the srelplt
BFD section and its offset from the output_secttion
bfd/
PR ld/30787
* elfxx-x86.c (_bfd_x86_elf_finish_dynamic_sections): Use input
section for DT_JMPREL and DT_PLTRELSZ.
ld/
PR ld/30787
* testsuite/ld-i386/i386.exp: Run pr30787.
* testsuite/ld-x86-64/x86-64.exp: Likewise.
* testsuite/ld-i386/pr30787.d: New file.
* testsuite/ld-i386/pr30787.s: Likewise.
* testsuite/ld-i386/pr30787.t: Likewise.
* testsuite/ld-x86-64/pr30787.d: Likewise.
* testsuite/ld-x86-64/pr30787.s: Likewise.
* testsuite/ld-x86-64/pr30787.t: Likewise.
SFrame version 2 encodes the size of repetitive insn block explicitly
in the format. Add information in the SFrame FDE to convey the size
of the block of repeating instructions. This information is used only
for SFrame FDEs of type SFRAME_FDE_TYPE_PCMASK.
Introduce two extra bytes for padding: this ensures that the memory
accesses to the members of the SFrame Frame Descriptor Entry (FDE) are
naturally aligned.
gas generates SFrame section with version SFRAME_VERSION_2 by default.
libsframe provides two new APIs to:
- get an SFrame FDE data from the decoder context, and
- add an SFrame FDE to the encoder context.
The additional argument (for rep_block_size) is useful for SFrame FDEs
where FDE type is SFRAME_FDE_TYPE_PCMASK.
The linker will generate the output SFrame sections in the
SFRAME_VERSION_2 format. If the input sections offered to the linker
are not all in the SFRAME_VERSION_2 format, the linker issues an error
to the user.
objdump/readelf will show the following message to the user if .sframe
section in SFRAME_VERSION_1 format is seen:
"No further information can be displayed. SFrame version not
supported."
In other words, like the rest of the binutils, only the current SFrame
format version, i.e., SFRAME_VERSION_2 is supported by the textual dump
facilities.
bfd/
* elf-sframe.c (_bfd_elf_merge_section_sframe): Generate an
output SFrame section with version SFRAME_VERSION_2. Also,
error out if the SFrame sections do not all have
SFRAME_VERSION_2.
* elfxx-x86.c (_bfd_x86_elf_create_sframe_plt): Generate SFrame
section for plt entries with version SFRAME_VERSION_2.
gas/
* gen-sframe.c (sframe_set_version): Update to SFRAME_VERSION_2.
(output_sframe): Likewise.
gas/testsuite/
* gas/cfi-sframe/cfi-sframe-aarch64-1.d: Use SFRAME_VERSION_2.
* gas/cfi-sframe/cfi-sframe-aarch64-2.d: Likewise.
* gas/cfi-sframe/cfi-sframe-aarch64-pac-ab-key-1.d: Likewise.
* gas/cfi-sframe/cfi-sframe-common-1.d: Likewise.
* gas/cfi-sframe/cfi-sframe-common-2.d: Likewise.
* gas/cfi-sframe/cfi-sframe-common-3.d: Likewise.
* gas/cfi-sframe/cfi-sframe-common-4.d: Likewise.
* gas/cfi-sframe/cfi-sframe-common-5.d: Likewise.
* gas/cfi-sframe/cfi-sframe-common-6.d: Likewise.
* gas/cfi-sframe/cfi-sframe-common-7.d: Likewise.
* gas/cfi-sframe/cfi-sframe-common-8.d: Likewise.
* gas/cfi-sframe/cfi-sframe-x86_64-1.d: Likewise.
* gas/cfi-sframe/common-empty-1.d: Likewise.
* gas/cfi-sframe/common-empty-2.d: Likewise.
* gas/cfi-sframe/common-empty-3.d: Likewise.
ld/testsuite/
* ld-aarch64/sframe-simple-1.d: Adjust for SFRAME_VERSION_2.
* ld-x86-64/sframe-plt-1.d: Likewise.
* ld-x86-64/sframe-simple-1.d: Likewise.
libsframe/
* libsframe.ver: Add the new APIs.
* sframe.c (sframe_decoder_get_funcdesc_v2): New definition.
(sframe_encoder_add_funcdesc_v2): Likewise.
(sframe_header_sanity_check_p): Include SFRAME_VERSION_2.
(sframe_fre_check_range_p): Get rep_block_size info from SFrame
FDE.
* sframe-dump.c (dump_sframe_header): Add support for
SFRAME_VERSION_2.
(dump_sframe): Inform user if SFrame section in SFRAME_VERSION_1
format is seen.
libsframe/testsuite/
* libsframe.decode/DATA-BE: Regenerated data file.
* libsframe.decode/DATA1: Likewise.
* libsframe.decode/DATA2: Likewise.
* libsframe.find/plt-findfre-1.c: Use new API in the testcase.
include/
* sframe.h: Add member to encode size of the code block of
repeating instructions. Add 2 bytes of padding.
* sframe-api.h (sframe_decoder_get_funcdesc_v2): New
declaration.
(sframe_encoder_add_funcdesc_v2): Likewise.
Use uint32_t type alias consistently for all APIs in libsframe.
bfd/
* elfxx-x86.c (_bfd_x86_elf_create_sframe_plt): Adjust for the
changed return type.
libsframe/
* sframe.c (sframe_calc_fre_type): Use uint32_t for return type.
include/
* sframe-api.h (sframe_calc_fre_type): Likewise.
When --no-keep-memory is used, the symbol buffer and the relocation
buffer aren't cached. When packing relative relocations, we may
allocate a new symbol buffer and a new relocation buffer for each
eligible section in an object file. If there are many sections,
memory may be exhausted. In this case, we should free the symbol
buffer and the relocation buffer after use. If symbol buffer entries
are used to track relative relocations against local symbols for later
use, the symbol buffer should be cached.
PR ld/30566
* elfxx-x86.c (elf_x86_relative_reloc_record_add): Add an
argument to inform caller if the symbol buffer should be kept.
(_bfd_x86_elf_link_relax_section): Call
_bfd_elf_link_info_read_relocs instead of
_bfd_elf_link_read_relocs. Free the symbol buffer and the
relocation buffer after use. Cache the symbol buffer if it
is used.
SFrame format is meant for generating stack traces only.
bfd/
* elf-bfd.h: Replace the use of "unwind" with "stack trace".
* elf-sframe.c: Likewise.
* elf64-x86-64.c: Likewise.
* elfxx-x86.c: Likewise.
include/
* elf/common.h: Likewise.
The newer update-copyright.py fixes file encoding too, removing cr/lf
on binutils/bfdtest2.c and ld/testsuite/ld-cygwin/exe-export.exp, and
embedded cr in binutils/testsuite/binutils-all/ar.exp string match.
When --no-keep-memory is used, the input section memory may not be cached.
Allocate input section memory for -z pack-relative-relocs if needed.
bfd/
PR ld/29939
* elfxx-x86.c (elf_x86_size_or_finish_relative_reloc): Allocate
input section memory if needed.
ld/
PR ld/29939
* testsuite/ld-elf/dt-relr-2i.d: New test.
The new name better reflects the purpose of the function.
ChangeLog:
* bfd/elfxx-x86.c (_bfd_x86_elf_create_sframe_plt): Use new
name.
* libsframe/sframe.c (sframe_fde_create_func_info): Rename
sframe_fde_func_info to this.
* libsframe/testsuite/libsframe.encode/encode-1.c: Use new name.
include/ChangeLog:
* sframe-api.h (sframe_fde_create_func_info): Rename
sframe_fde_func_info to this.
The linker merges all the input .sframe sections. When merging, the
linker verifies that all the input .sframe sections have the same
abi/arch.
The linker uses libsframe library to perform key actions on the
.sframe sections - decode, read, and create output data. This
implies buildsystem changes to make and install libsframe before
libbfd.
The linker places the output .sframe section in a new segment of its
own: PT_GNU_SFRAME. A new segment is not added, however, if the
generated .sframe section is empty.
When a section is discarded from the final link, the corresponding
entries in the .sframe section for those functions are also deleted.
The linker sorts the SFrame FDEs on start address by default and sets
the SFRAME_F_FDE_SORTED flag in the .sframe section.
This patch also adds support for generation of SFrame unwind
information for the .plt* sections on x86_64. SFrame unwind info is
generated for IBT enabled PLT, lazy/non-lazy PLT.
The existing linker option --no-ld-generated-unwind-info has been
adapted to include the control of whether .sframe unwind information
will be generated for the linker generated sections like PLT.
Changes to the linker script have been made as necessary.
ChangeLog:
* Makefile.def: Add install dependency on libsframe for libbfd.
* Makefile.in: Regenerated.
* bfd/Makefile.am: Add elf-sframe.c
* bfd/Makefile.in: Regenerated.
* bfd/bfd-in2.h (SEC_INFO_TYPE_SFRAME): Regenerated.
* bfd/configure: Regenerate.
* bfd/configure.ac: Add elf-sframe.lo.
* bfd/elf-bfd.h (struct sframe_func_bfdinfo): New struct.
(struct sframe_dec_info): Likewise.
(struct sframe_enc_info): Likewise.
(struct elf_link_hash_table): New member for encoded .sframe
object.
(struct output_elf_obj_tdata): New member.
(elf_sframe): New access macro.
(_bfd_elf_set_section_sframe): New declaration.
* bfd/elf.c (get_segment_type): Handle new segment
PT_GNU_SFRAME.
(bfd_section_from_phdr): Likewise.
(get_program_header_size): Likewise.
(_bfd_elf_map_sections_to_segments): Likewise.
* bfd/elf64-x86-64.c (elf_x86_64_link_setup_gnu_properties): Add
contents to the .sframe sections or .plt* entries.
* bfd/elflink.c (elf_section_ignore_discarded_relocs): Handle
SEC_INFO_TYPE_SFRAME.
(_bfd_elf_default_action_discarded): Handle .sframe section.
(elf_link_input_bfd): Merge .sframe section.
(bfd_elf_final_link): Write the output .sframe section.
(bfd_elf_discard_info): Handle discarding .sframe section.
* bfd/elfxx-x86.c (_bfd_x86_elf_size_dynamic_sections): Create
.sframe section for .plt and .plt.sec.
(_bfd_x86_elf_finish_dynamic_sections): Handle .sframe from
.plt* sections.
* bfd/elfxx-x86.h (PLT_SFRAME_FDE_START_OFFSET): New
definition.
(SFRAME_PLT0_MAX_NUM_FRES): Likewise.
(SFRAME_PLTN_MAX_NUM_FRES): Likewise.
(struct elf_x86_sframe_plt): New structure.
(struct elf_x86_link_hash_table): New member.
(struct elf_x86_init_table): New members for .sframe
creation.
* bfd/section.c: Add new definition SEC_INFO_TYPE_SFRAME.
* binutils/readelf.c (get_segment_type): Handle new segment
PT_GNU_SFRAME.
* ld/ld.texi: Update documentation for
--no-ld-generated-unwind-info.
* ld/scripttempl/elf.sc: Support .sframe sections.
* ld/Makefile.am (TESTSFRAMELIB): Use it.
(check-DEJAGNU): Likewise.
* ld/Makefile.in: Regenerated.
* ld/configure.ac (TESTSFRAMELIB): Set to the .so or .a like TESTBFDLIB.
* ld/configure: Regenerated.
* bfd/elf-sframe.c: New file.
include/ChangeLog:
* elf/common.h (PT_GNU_SFRAME): New definition.
* elf/internal.h (struct elf_segment_map): Handle new segment
type PT_GNU_SFRAME.
ld/testsuite/ChangeLog:
* ld/testsuite/ld-bootstrap/bootstrap.exp: Add SFRAMELIB.
* ld/testsuite/ld-aarch64/aarch64-elf.exp: Add new test
sframe-simple-1.
* ld/testsuite/ld-aarch64/sframe-bar.s: New file.
* ld/testsuite/ld-aarch64/sframe-foo.s: Likewise.
* ld/testsuite/ld-aarch64/sframe-simple-1.d: Likewise.
* ld/testsuite/ld-sframe/sframe-empty.d: New test.
* ld/testsuite/ld-sframe/sframe-empty.s: New file.
* ld/testsuite/ld-sframe/sframe.exp: New testsuite.
* ld/testsuite/ld-x86-64/sframe-bar.s: New file.
* ld/testsuite/ld-x86-64/sframe-foo.s: Likewise.
* ld/testsuite/ld-x86-64/sframe-simple-1.d: Likewise.
* ld/testsuite/ld-x86-64/sframe-plt-1.d: Likewise.
* ld/testsuite/ld-x86-64/sframe-simple-1.d: Likewise.
* ld/testsuite/ld-x86-64/x86-64.exp: Add new tests -
sframe-simple-1, sframe-plt-1.
* ld/testsuite/lib/ld-lib.exp: Add new proc to check if
assembler supports SFrame section.
* ld/testsuite/ld-sframe/discard.d: New file.
* ld/testsuite/ld-sframe/discard.ld: Likewise.
* ld/testsuite/ld-sframe/discard.s: Likewise.
Since glibc 2.36 will issue warnings for copy relocation against
protected symbols and non-canonical reference to canonical protected
functions, change the linker to always disallow such relocations.
bfd/
* elf32-i386.c (elf_i386_scan_relocs): Remove check for
elf_has_indirect_extern_access.
* elf64-x86-64.c (elf_x86_64_scan_relocs): Likewise.
(elf_x86_64_relocate_section): Remove check for
elf_has_no_copy_on_protected.
* elfxx-x86.c (elf_x86_allocate_dynrelocs): Check for building
executable instead of elf_has_no_copy_on_protected.
(_bfd_x86_elf_adjust_dynamic_symbol): Disallow copy relocation
against non-copyable protected symbol.
* elfxx-x86.h (SYMBOL_NO_COPYRELOC): Remove check for
elf_has_no_copy_on_protected.
ld/
* testsuite/ld-i386/i386.exp: Expect linker error for PR ld/17709
test.
* testsuite/ld-i386/pr17709.rd: Removed.
* testsuite/ld-i386/pr17709.err: New file.
* testsuite/ld-x86-64/pr17709.rd: Removed.
* testsuite/ld-x86-64/pr17709.err: New file.
* testsuite/ld-x86-64/pr28875-func.err: Updated.
* testsuite/ld-x86-64/x86-64.exp: Expect linker error for PR
ld/17709 test. Add tests for function pointer against protected
function.
Call _bfd_elf_symbol_refs_local_p with local_protected==true. This has
2 noticeable effects for -shared:
* GOT-generating relocations referencing a protected data symbol no
longer lead to a GLOB_DAT (similar to a hidden symbol).
* Direct access relocations (e.g. R_X86_64_PC32) no longer has the
confusing diagnostic below.
__attribute__((visibility("protected"))) void *foo() {
return (void *)foo;
}
// gcc -fpic -shared -fuse-ld=bfd
relocation R_X86_64_PC32 against protected symbol `foo' can not be used when making a shared object
The new behavior matches arm, aarch64 (commit
83c325007c), and powerpc ports, and other
linkers: gold and ld.lld.
Note: if some code tries to use direct access relocations to take the
address of foo, the pointer equality will break, but the error should be
reported on the executable link, not on the innocent shared object link.
glibc 2.36 will give a warning at relocation resolving time.
With this change, `#define elf_backend_extern_protected_data 1` is no
longer effective. Just remove it.
Remove the test "Run protected-func-1 without PIE" since -fno-pic
address taken operation in the executable doesn't work with protected
symbol in a shared object by default. Similarly, remove
protected-data-1a and protected-data-1b. protected-data-1b can be made
working by removing HAVE_LD_PIE_COPYRELOC from GCC
(https://sourceware.org/pipermail/gcc-patches/2022-June/596678.html).
I am checking this into master and will backport it to 2.38 branch.
H.J
----
On x86, GCC 12 supports -mno-direct-extern-access to enable canonical
reference to protected function and disable copy relocation. With
-mno-direct-extern-access, the canonical protected function symbols must
be accessed via canonical reference and the protected data symbols in
shared libraries are non-copyable. Under glibc 2.35, non-canonical
reference to the canonical protected function will get the run-time error:
./y: internal_f: ./libfoo.so: non-canonical reference to canonical protected function
and copy relocations against the non-copyable protected symbols will get
the run-time error:
./x: internal_i: ./libfoo.so: copy relocation against non-copyable protected symbol
Update x86 linker to disallow non-canonical reference to the canonical
protected function:
ld: plt.o: non-canonical reference to canonical protected function `internal_f' in libfoo.so
ld: failed to set dynamic section sizes: bad value
and copy relocation against the non-copyable protected symbol:
ld: main.o: copy relocation against non-copyable protected symbol `internal_i' in libfoo.so
at link-time.
bfd/
PR ld/28875
* elf-properties.c (_bfd_elf_parse_gnu_properties): Don't skip
shared libraries for GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS.
* elf32-i386.c (elf_i386_scan_relocs): Disallow non-canonical
reference to canonical protected function.
* elf64-x86-64.c (elf_x86_64_scan_relocs): Likewise.
* elfxx-x86.c (elf_x86_allocate_dynrelocs): Don't allow copy
relocation against non-copyable protected symbol.
ld/
PR ld/28875
* testsuite/ld-i386/i386.exp: Check non-canonical reference to
canonical protected function and check copy relocation against
non-copyable protected symbol.
* testsuite/ld-i386/pr21997-1.err: New file.
* testsuite/ld-i386/pr28875.err: Likewise.
* testsuite/ld-i386/pr28875a.c: Likewise.
* testsuite/ld-i386/pr28875b.c: Likewise.
* testsuite/ld-x86-64/pr21997-1a.err: Updated.
* testsuite/ld-x86-64/pr21997-1b.err: Likewise.
* testsuite/ld-x86-64/pr28875-data.err: New file.
* testsuite/ld-x86-64/pr28875-func.err: Likewise.
* testsuite/ld-x86-64/x86-64.exp: Check non-canonical reference
to canonical protected function and check copy relocation against
non-copyable protected symbol.
GOT32 relocations are allowed since absolute value + addend is stored in
the GOT slot.
Tested on glibc 2.35 build with GCC 11.2 and -Os.
bfd/
PR ld/28870
* elfxx-x86.c (_bfd_elf_x86_valid_reloc_p): Also allow GOT32
relocations.
ld/
PR ld/28870
* testsuite/ld-i386/i386.exp: Run pr28870.
* testsuite/ld-i386/pr28870.d: New file.
* testsuite/ld-i386/pr28870.s: Likewise.
Don't abort for undefined symbol when finishing DT_RELR. Instead, skip
undefined symbol. Undefined symbol will be reported by relocate_section.
* elfxx-x86.c (elf_x86_size_or_finish_relative_reloc): Skip
undefined symbol in finishing phase.
This makes the code setting DT_RELR tags generally available. Many
targets will be able to use the defaults. Those that can't should set
up sh_entsize for .relr.dyn output section before reaching the dynamic
tag code in bfd_elf_final_link.
* elflink.c (bfd_elf_final_link): Set up DT_RELR tags and sh_entsize.
* elfxx-x86.c (_bfd_x86_elf_finish_dynamic_sections): Don't do any
of that here.
DT_RELR is implemented with linker relaxation:
1. During linker relaxation, we scan input relocations with the same
logic in relocate_section to determine if a relative relocation should
be generated and save the relative relocation candidate information for
sizing the DT_RELR section later after all symbols addresses can be
determined. For these relative relocations which can't be placed in
the DT_RELR section, they will be placed in the rela.dyn/rel.dyn
section.
2. When DT_RELR is enabled, _bfd_elf_map_sections_to_segments calls a
backend function to size the DT_RELR section which will compute the
DT_RELR section size and tell ldelf_map_segments to layout sections
again when the DT_RELR section size has been increased.
3. After regular symbol processing is finished, bfd_elf_final_link calls
a backend function to finish the DT_RELR section.
* elf32-i386.c (elf_i386_relocate_section): Don't generate
relative relocation when DT_RELR is enabled.
(elf_i386_finish_dynamic_symbol): Likewise.
* elf64-x86-64.c (elf_x86_64_relocate_section): Don't generate
relative relocation when DT_RELR is enabled.
(elf_x86_64_finish_dynamic_symbol): Likewise.
* elfxx-x86.c (_bfd_x86_elf_link_hash_table_create): Initialize
relative_r_type, relative_r_name, elf_append_reloc,
elf_write_addend and elf_write_addend_in_got.
(elf_x86_relative_reloc_record_add): New function.
(_bfd_x86_elf_link_relax_section): Likewise.
(elf64_dt_relr_bitmap_add): Likewise.
(elf32_dt_relr_bitmap_add): Likewise.
(_bfd_elf32_write_addend): Likewise.
(_bfd_elf64_write_addend): Likewise.
(elf_x86_size_or_finish_relative_reloc): Likewise.
(elf_x86_compute_dl_relr_bitmap): Likewise.
(elf_x86_write_dl_relr_bitmap): Likewise.
(elf_x86_relative_reloc_compare ): Likewise.
(_bfd_elf_x86_size_relative_relocs): Likewise.
(_bfd_elf_x86_finish_relative_relocs): Likewise.
(_bfd_x86_elf_size_dynamic_sections): Skip the .relr.dyn section.
(_bfd_x86_elf_finish_dynamic_sections): Convert 3 spare dynamic
tags to DT_RELR, DT_RELRSZ and for compact relative relocation.
* elfxx-x86.h (X86_64_GOT_TYPE_P): New.
(I386_GOT_TYPE_P): Likewise.
(X86_GOT_TYPE_P): Likewise.
(X86_64_RELATIVE_RELOC_TYPE_P): Likewise.
(I386_RELATIVE_RELOC_TYPE_P): Likewise.
(X86_RELATIVE_RELOC_TYPE_P): Likewise.
(X86_LOCAL_GOT_RELATIVE_RELOC_P): Likewise.
(I386_PCREL_TYPE_P): Likewise.
(X86_64_PCREL_TYPE_P): Likewise.
(X86_64_NEED_DYNAMIC_RELOC_TYPE_P): Rewrite.
(I386_NEED_DYNAMIC_RELOC_TYPE_P): Likewise.
(GENERATE_DYNAMIC_RELOCATION_P): Also check rel_from_abs.
(elf_x86_link_hash_entry): Add got_relative_reloc_done.
(elf_x86_relative_reloc_record): New.
(elf_x86_relative_reloc_data): Likewise.
(elf_dt_relr_bitmap): Likewise.
(elf_x86_link_hash_table): Add dt_relr_bitmap, relative_reloc,
unaligned_relative_reloc, relative_r_type, relative_r_name,
elf_append_reloc, elf_write_addend, elf_write_addend_in_got and
relative_reloc_done.
(elf_x86_relative_reloc_done): New.
(relative_reloc_packed): Likewise.
(_bfd_x86_elf_link_relax_section): Likewise.
(_bfd_elf_x86_size_relative_relocs): Likewise.
(_bfd_elf_x86_finish_relative_relocs): Likewise.
(_bfd_elf32_write_addend): Likewise.
(_bfd_elf64_write_addend): Likewise.
(bfd_elf32_bfd_relax_section): Likewise.
(bfd_elf64_bfd_relax_section): Likewise.
(elf_backend_size_relative_relocs): Likewise.
(elf_backend_finish_relative_relocs): Likewise.
(elf_x86_allocate_local_got_info): Also allocate
relative_reloc_done.
DT_RELR encodes consecutive R_*_RELATIVE relocations in GOT (the global
offset table) and data sections in a compact format:
https://groups.google.com/g/generic-abi/c/bX460iggiKg
On some targets, R_*_RELATIVE relocations are counted and the GOT offsets
are allocated when setting the dynamic section sizes after seeing all
relocations. R_*_RELATIVE relocations are generated while relocating
sections after section layout has been finalized.
To prepare for DT_RELR implementation on these targets, extract
_bfd_elf_link_iterate_on_relocs from _bfd_elf_link_check_relocs so
that a backend can scan relocations in elf_backend_always_size_sections
For x86 targets, the old check_relocs is renamed to scan_relocs and a
new check_relocs is added to chek input sections and create dynamic
relocation sections so that they will be mapped to output sections.
scan_relocs is now called from elf_backend_always_size_sections.
Since relocations are scanned after __start, __stop, .startof. and
.sizeof. symbols have been finalized on x86, __[start|stop]_SECNAME for
--gc-sections -z start-stop-gc are now zero when all SECNAME sections
been garbage collected. This is no need for elf_x86_start_stop_gc_p.
bfd/
* elf-bfd.h (_bfd_elf_link_iterate_on_relocs): New.
* elf32-i386.c (elf_i386_convert_load_reloc): Don't call
elf_x86_start_stop_gc_p.
(elf_i386_check_relocs): Renamed to ...
(elf_i386_scan_relocs): This. Don't call
_bfd_elf_make_dynamic_reloc_section.
(elf_i386_always_size_sections): New.
(elf_backend_check_relocs): Removed.
(elf_backend_always_size_sections): New.
* elf64-x86-64.c (elf_x86_64_convert_load_reloc): Don't call
elf_x86_start_stop_gc_p.
(elf_x86_64_check_relocs): Renamed to ...
(elf_x86_64_scan_relocs): This. Don't call
_bfd_elf_make_dynamic_reloc_section.
(elf_x86_64_always_size_sections): New.
(elf_backend_check_relocs): Removed.
(elf_backend_always_size_sections): New.
* elflink.c (elf_link_check_or_scan_relocs):
New. Extracted from _bfd_elf_link_check_relocs.
(_bfd_elf_link_check_relocs): Call elf_link_check_or_scan_relocs.
* elfxx-x86.c (_bfd_x86_elf_check_relocs): New.
* elfxx-x86.h (X86_64_NEED_DYNAMIC_RELOC_TYPE_P): New.
(I386_NEED_DYNAMIC_RELOC_TYPE_P): Likewise.
(X86_NEED_DYNAMIC_RELOC_TYPE_P): Likewise.
(_bfd_x86_elf_check_relocs): Likewise.
(elf_backend_check_relocs): Likewise.
(elf_backend_always_size_sections): Removed.
(elf_x86_start_stop_gc_p): Likewise.
ld/
* testsuite/ld-i386/pr27491-1a.d: Updated.
* testsuite/ld-x86-64/pr27491-1a.d: Likewise.
Use 0x%v, instead of bfd_sprintf_vma, to report relative relocations.
Change linker relative relocations report from
tmpdir/dump: R_X86_64_IRELATIVE (offset: 0x0000000000002000, info: 0x0000000000000025, addend: 0x0000000000001007) against 'ifunc' for section '.data.rel.ro.local' in tmpdir/report-reloc-1.o
to
tmpdir/dump: R_X86_64_IRELATIVE (offset: 0x2000, info: 0x25, addend: 0x1007) against 'ifunc' for section '.data.rel.ro.local' in tmpdir/report-reloc-1.o
bfd/
* elfxx-x86.c (_bfd_x86_elf_link_report_relative_reloc): Use
0x%v instead of bfd_sprintf_vma.
ld/
* testsuite/ld-i386/report-reloc-1.l: Updated.
* testsuite/ld-x86-64/report-reloc-1.l: Likewise.
The result of running etc/update-copyright.py --this-year, fixing all
the files whose mode is changed by the script, plus a build with
--enable-maintainer-mode --enable-cgen-maint=yes, then checking
out */po/*.pot which we don't update frequently.
The copy of cgen was with commit d1dd5fcc38ead reverted as that commit
breaks building of bfp opcodes files.
If GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS is set on any input
relocatable files:
1. Don't generate copy relocations.
2. Turn off extern_protected_data since it implies
GNU_PROPERTY_NO_COPY_ON_PROTECTED.
3. Treate reference to protected symbols with indirect external access
as local.
4. Set GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS on output.
5. When generating executable, clear this bit when there are non-GOT or
non-PLT relocations in input relocatable files without the bit set.
6. Add -z [no]indirect-extern-access to control indirect external access.
bfd/
* elf-bfd (elf_obj_tdata): Add has_indirect_extern_access.
(elf_has_indirect_extern_access): New.
* elf-properties.c (_bfd_elf_parse_gnu_properties): Set
elf_has_indirect_extern_access and elf_has_no_copy_on_protected
when seeing GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS.
(elf_write_gnu_propertie): Add an argument to pass link_info.
Set needed_1_p for GNU_PROPERTY_1_NEEDED in memory.
(_bfd_elf_link_setup_gnu_properties): Handle
GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS for
-z indirect-extern-access. Set nocopyreloc to true and
extern_protected_data to false for indirect external access.
(_bfd_elf_convert_gnu_properties): Updated.
* elf32-i386.c (elf_i386_check_relocs): Set
non_got_ref_without_indirect_extern_access on legacy non-GOT or
non-PLT references.
* elf64-x86-64.c (elf_x86_64_check_relocs): Likewise.
* elflink.c (_bfd_elf_symbol_refs_local_p): Return true for
STV_PROTECTED symbols with indirect external access.
* elfxx-x86.c (_bfd_x86_elf_adjust_dynamic_symbol): Clear
indirect_extern_access for legacy non-GOT/non-PLT references.
* elfxx-x86.h (elf_x86_link_hash_entry): Add
non_got_ref_without_indirect_extern_access.
include/
* bfdlink.h (bfd_link_info): Add indirect_extern_access and
needed_1_p. Change nocopyreloc to int.
ld/
* NEWS: Mention -z [no]indirect-extern-access
* ld.texi: Document -z [no]indirect-extern-access
* ldmain.c (main): Initialize link_info.indirect_extern_access
to -1.
* emulparams/extern_protected_data.sh: Support
-z [no]indirect-extern-access.
* testsuite/ld-elf/indirect-extern-access-1.rd: New file
* testsuite/ld-elf/indirect-extern-access-1a.c: Likewise.
* testsuite/ld-elf/indirect-extern-access-1b.c: Likewise.
* testsuite/ld-elf/indirect-extern-access-2.rd: Likewise.
* testsuite/ld-elf/indirect-extern-access-2a.c: Likewise.
* testsuite/ld-elf/indirect-extern-access-2b.c: Likewise.
* testsuite/ld-elf/indirect-extern-access-3.rd: Likewise.
* testsuite/ld-elf/indirect-extern-access.S: Likewise.
* testsuite/ld-elf/property-1_needed-1b.d: Likewise.
* testsuite/ld-elf/property-1_needed-1c.d: Likewise.
* testsuite/ld-x86-64/indirect-extern-access.rd: Likewise.
* testsuite/ld-x86-64/protected-data-1.h: Likewise.
* testsuite/ld-x86-64/protected-data-1a.c: Likewise.
* testsuite/ld-x86-64/protected-data-1b.c: Likewise.
* testsuite/ld-x86-64/protected-data-2a.S: Likewise.
* testsuite/ld-x86-64/protected-data-2b.S: Likewise.
* testsuite/ld-x86-64/protected-func-2a.S: Likewise.
* testsuite/ld-x86-64/protected-func-2b.S: Likewise.
* testsuite/ld-x86-64/protected-func-2c.c: Likewise.
* testsuite/ld-elf/linux-x86.exp: Run test with
GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS.
* testsuite/ld-x86-64/x86-64.exp: Run tests for protected
function and data with indirect external access.
Since GOTOFF relocations against IFUNC symbols must go through PLT,
set PLT reference count to 1 for GOTOFF relocation.
bfd/
PR ld/27998
* elfxx-x86.c (elf_x86_allocate_dynrelocs): Count PLT for GOTOFF
relocation against IFUNC symbols.
(_bfd_x86_elf_adjust_dynamic_symbol): Likewise.
ld/
PR ld/27998
* testsuite/ld-i386/i386.exp: Run PR ld/27998 tests.
* testsuite/ld-i386/pr27998a.d: New file.
* testsuite/ld-i386/pr27998a.s: Likewise.
* testsuite/ld-i386/pr27998b.d: Likewise.
* testsuite/ld-i386/pr27998b.s: Likewise.
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.
On x86, glibc 2.33 starts to issue a fatal error message when calling
IFUNC function defined in the unrelocated executable from a shared
library.
1. Update x86 ELF linker to always convert IFUNC function defined in
position-dependent executable (PDE) to the normal function. GOT in PDE
will be updated by R_*_IRELATIVE at run-time.
2. Update PR ld/23169 tests not to compare function address of external
IFUNC function in the shared object to avoid calling the IFUNC function
defined in the unrelocated executable.
3. Remove pr23169e tests which call the IFUNC function defined in the
unrelocated position-independent executable from a shared library.
bfd/
PR ld/23169
* elfxx-x86.c (_bfd_x86_elf_link_fixup_ifunc_symbol): Don't
check pointer_equality_needed.
ld/
PR ld/23169
* testsuite/ld-ifunc/ifunc.exp: Replace pr23169c.rd with
pr23169a.rd for pr23169c and pr23169f. Remove pr23169e tests.
* testsuite/ld-ifunc/pr23169a.c (foo): Don't compare function
address.
Since LAM_U48 implies LAM_U57, also set LAM_U57 when setting LAM_U48.
bfd/
* elfxx-x86.c (_bfd_x86_elf_link_setup_gnu_properties): Also set
LAM_U57 when setting LAM_U48.
ld/
* ld-x86-64/property-x86-lam-u48-4.d: Updated.
* ld-x86-64/property-x86-lam-u48-5.d: Likewise.