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 uint8_t consistently for identifying ABI/arch in SFrame format.
bfd/
* elf-sframe.c (_bfd_elf_merge_section_sframe):
libsframe/
* sframe-dump.c (is_sframe_abi_arch_aarch64): Use uint8_t for
local variable.
* sframe.c (sframe_decoder_get_abi_arch): Update return type to
uint8_t.
(sframe_encoder_get_abi_arch): Likewise.
include/
* sframe-api.h (sframe_decoder_get_abi_arch): Likewise.
(sframe_encoder_get_abi_arch): Likewise.
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.
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.
