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.
While the SFrame preamble is guaranteed to not change between versions,
providing these access APIs from the SFrame decoder and encoder APIs is
for convenience only. The linker may want to use these APIs as the
format evolves.
include/
* sframe-api.h (sframe_decoder_get_version): New declaration.
(sframe_encoder_get_version): Likewise.
libsframe/
* libsframe/libsframe.ver: Add new APIs.
* libsframe/sframe.c (sframe_decoder_get_version): New
definition.
(sframe_encoder_get_version): Likewise.
Use a more appropriate data type.
include/
* sframe-api.h (sframe_fre_get_base_reg_id): Use uint8_t as
return type.
libsframe/
* sframe-dump.c (dump_sframe_func_with_fres): Use uint8_t type
for base reg id.
* sframe.c (sframe_fre_get_base_reg_id): Use uin8_t as return
type.
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.
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.
The API sframe_fde_create_func_info is provided by libsframe. Current
users are the bfd linker. Adjust the argument type for the variables
carrying the SFrame FRE type and SFrame FDE type to consistenly use
uint32_t type alias.
include/
* sframe-api.h (sframe_fde_create_func_info): Use uint32_t
instead of unsigned int.
libsframe/
* sframe.c (sframe_get_fre_type): Likewise.
(sframe_get_fde_type): Likewise.
(flip_fre_start_address): Likewise.
(sframe_fre_start_addr_size): Likewise.
(sframe_fre_entry_size): Likewise.
(flip_fre): Likewise.
(flip_sframe): Likewise.
(sframe_fde_create_func_info): Likewise.
(sframe_calc_fre_type): Likewise.
(sframe_decode_fre_start_address): Likewise.
(sframe_decode_fre): Likewise.
(sframe_find_fre): Likewise.
(sframe_decoder_get_fre): Likewise.
(sframe_encoder_add_fre): Likewise.
(sframe_encoder_write_fre_start_addr): Likewise.
(sframe_encoder_write_fre): Likewise.
(sframe_encoder_write_sframe): Likewise.
This is an incompatible ABI change in libsframe.
The interface provided by this function is not a healthy abstraction to
expose: the return type sframe_func_desc_entry, which is defined in
include/sframe.h (the SFrame binary format definition). This ties up
the library in a undesirable way. Most importantly, this function
should technically not be directly necessary for a stack tracer. A
stack tracer will likely only need to do a sframe_find_fre ().
Rename the API to continue to use the functionality internally in the
library. bfd/linker does not use this function.
Change the return type of the previous definition and make a note about
its planned deprecation.
include/
* sframe-api.h: Change return type of sframe_get_funcdesc_with_addr.
Add comment for intention to deprecate.
libsframe/
*sframe.c (sframe_get_funcdesc_with_addr): Change return type
and set error code. This API is deprecated.
(sframe_get_funcdesc_with_addr_internal): New definition for
internal use.
(sframe_find_fre): Use sframe_get_funcdesc_with_addr_internal
instead.
include/
* sframe-api.h (sframe_decoder_get_num_fidx): Use extern.
libsframe/
* sframe-dump.c (dump_sframe_func_with_fres): Fix line length.
* sframe.c (sframe_frame_row_entry_copy): Likewise.
(sframe_decode_fre_start_address): Use the intended type uint32_t.
Define a new constant for the maximum number of stack offsets handled in
libsframe, and use it. Note that the SFrame format does not define such
a constant (limit). This is an implmentation-defined constant in
libsframe.
include/
* sframe-api.h (MAX_NUM_STACK_OFFSETS): New definition.
libsframe/
* sframe.c (sframe_fre_sanity_check_p): Use it.
An earlier commit 3f107464 defined the SFRAME_FRE_TYPE_*_LIMIT
constants. These constants are used (by gas and libsframe) to pick an
SFrame FRE type based on the function size. Those constants, however,
were buggy, causing the generated SFrame sections to be bloated as
SFRAME_FRE_TYPE_ADDR2/SFRAME_FRE_TYPE_ADDR4 got chosen more often than
necessary.
gas/
* sframe-opt.c (sframe_estimate_size_before_relax): Use
typecast.
(sframe_convert_frag): Likewise.
libsframe/
* sframe.c (sframe_calc_fre_type): Use a more appropriate type
for argument. Adjust the check for SFRAME_FRE_TYPE_ADDR4_LIMIT
to keep it warning-free but meaningful.
include/
* sframe-api.h (sframe_calc_fre_type): Use a more appropriate
type for the argument.
* sframe.h (SFRAME_FRE_TYPE_ADDR1_LIMIT): Correct the constant.
(SFRAME_FRE_TYPE_ADDR2_LIMIT): Likewise.
(SFRAME_FRE_TYPE_ADDR4_LIMIT): 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.
There are two places where unaligned loads were seen on aarch64:
- #1. access to the SFrame FRE stack offsets in the in-memory
representation/abstraction provided by libsframe.
- #2. access to the SFrame FRE start address in the on-disk representation
of the frame row entry.
For #1, we can fix this by reordering the struct members of
sframe_frame_row_entry in libsframe/sframe-api.h.
For #2, we need to default to using memcpy instead, and copy out the bytes
to a location for output.
SFrame format is an unaligned on-disk format. As such, there are other blobs
of memory in the on-disk SFrame FRE that are on not on their natural
boundaries. But that does not pose further problems yet, because the users
are provided access to the on-disk SFrame FRE data via libsframe's
sframe_frame_row_entry, the latter has its' struct members aligned on their
respective natural boundaries (and initialized using memcpy).
PR 29856 libsframe asan: load misaligned at sframe.c:516
ChangeLog:
PR libsframe/29856
* bfd/elf64-x86-64.c: Adjust as the struct members have been
reordered.
* libsframe/sframe.c (sframe_decode_fre_start_address): Use
memcpy to perform 16-bit/32-bit reads.
* libsframe/testsuite/libsframe.encode/encode-1.c: Adjust as the
struct members have been reordered.
include/ChangeLog:
PR libsframe/29856
* sframe-api.h: Reorder fre_offsets for natural alignment.
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.
This patch adds support for SFrame in readelf and objdump. The arguments
of --sframe are optional for both readelf and objdump.
include/ChangeLog:
* sframe-api.h (dump_sframe): New function declaration.
ChangeLog:
* binutils/Makefile.am: Add dependency on libsframe for
readelf and objdump.
* binutils/Makefile.in: Regenerate.
* binutils/doc/binutils.texi: Document --sframe=[section].
* binutils/doc/sframe.options.texi: New file.
* binutils/objdump.c: Add support for SFrame format.
* binutils/readelf.c: Likewise.
* include/sframe-api.h: Add new API for dumping .sframe
section.
* libsframe/Makefile.am: Add sframe-dump.c.
* libsframe/Makefile.in: Regenerate.
* libsframe/sframe-dump.c: New file.
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.
libsframe is a library that allows you to:
- decode a .sframe section
- probe and inspect a .sframe section
- encode (and eventually write) a .sframe section.
This library is currently being used by the linker, readelf, objdump.
This library will also be used by the SFrame unwinder which is still
to be upstream'd.
The file include/sframe-api.h defines the user-facing APIs for decoding,
encoding and probing .sframe sections. A set of error codes together
with their error message strings are also defined.
Endian flipping is performed automatically at read and write time, if
cross-endianness is detected.
ChangeLog:
* Makefile.def: Add libsframe as new module with its
dependencies.
* Makefile.in: Regenerated.
* binutils/Makefile.am: Add libsframe.
* binutils/Makefile.in: Regenerated.
* configure: Regenerated
* configure.ac: Add libsframe to host_libs.
* libsframe/Makefile.am: New file.
* libsframe/Makefile.in: New file.
* libsframe/aclocal.m4: New file.
* libsframe/config.h.in: New file.
* libsframe/configure: New file.
* libsframe/configure.ac: New file.
* libsframe/sframe-error.c: New file.
* libsframe/sframe-impl.h: New file.
* libsframe/sframe.c: New file.
include/ChangeLog:
* sframe-api.h: New file.
testsuite/ChangeLog:
* libsframe/testsuite/Makefile.am: New file.
* libsframe/testsuite/Makefile.in: Regenerated.
* libsframe/testsuite/libsframe.decode/Makefile.am: New
file.
* libsframe/testsuite/libsframe.decode/Makefile.in:
Regenerated.
* libsframe/testsuite/libsframe.decode/decode.exp: New file.
* libsframe/testsuite/libsframe.encode/Makefile.am:
Likewise.
* libsframe/testsuite/libsframe.encode/Makefile.in:
Regenerated.
* libsframe/testsuite/libsframe.encode/encode.exp: New file.
* libsframe/testsuite/libsframe.encode/encode-1.c: Likewise.
* libsframe/testsuite/libsframe.decode/be-flipping.c: Likewise.
* libsframe/testsuite/libsframe.decode/frecnt-1.c: Likewise.
* libsframe/testsuite/libsframe.decode/frecnt-2.c: Likewise.
* libsframe/testsuite/libsframe.decode/DATA-BE: New file.
* libsframe/testsuite/libsframe.decode/DATA1: Likewise.
* libsframe/testsuite/libsframe.decode/DATA2: Likewise.
