| Age | Commit message (Collapse) | Author | Files | Lines |
|---|
|
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.
|
|
|
|
gas/
* gen-sframe.c (sframe_set_version): Use ATTRIBUTE_UNUSED
consistently.
(output_sframe): Likewise.
(sframe_set_fre_info): Remove the usage of ATTRIBUTE_UNUSED.
|
|
SFrame format is meant for generating stack traces only.
gas/
* as.c: Replace the use of "unwind" with "stack trace".
* config/tc-aarch64.c: Likewise.
* config/tc-aarch64.h: Likewise.
* config/tc-i386.c: Likewise.
* config/tc-i386.h: Likewise.
* gen-sframe.c: Likewise.
* gen-sframe.h: Likewise.
* testsuite/gas/cfi-sframe/cfi-sframe-aarch64-2.s: Likewise.
* testsuite/gas/cfi-sframe/cfi-sframe-common-8.s: Likewise.
* testsuite/gas/cfi-sframe/common-empty-2.s: Likewise.
* testsuite/gas/cfi-sframe/common-empty-3.s: 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.
|
|
Gather the information from the DWARF FDE on whether frame's return
addresses are signed using the B key or A key. Reflect the information in
the SFrame counterpart data structure, the SFrame FDE.
ChangeLog:
* gas/gen-sframe.c (get_dw_fde_pauth_b_key_p): New definition.
(sframe_v1_set_func_info): Add new argument for pauth_key.
(sframe_set_func_info): Likewise.
(output_sframe_funcdesc): Likewise.
* gas/gen-sframe.h (struct sframe_version_ops): Add new argument
to the function pointer declaration.
* gas/sframe-opt.c (sframe_convert_frag): Handle pauth_key.
|
|
DW_CFA_AARCH64_negate_ra_state in aarch64 is multiplexed with
DW_CFA_GNU_window_save in the DWARF format.
Remove the common-empty-4 testcase because the generated SFrame section
will not be be empty anymore. A relevant test will be added in a later
commit.
ChangeLog:
* gas/gen-sframe.c (sframe_v1_set_fre_info): Add new argument
for mangled_ra_p.
(sframe_set_fre_info): Likewise.
(output_sframe_row_entry): Handle mangled_ra_p.
(sframe_row_entry_new): Reset mangled_ra_p.
(sframe_row_entry_initialize): Initialize mangled_ra_p.
(sframe_xlate_do_gnu_window_save): New definition.
(sframe_do_cfi_insn): Handle DW_CFA_GNU_window_save.
* gas/gen-sframe.h (struct sframe_row_entry): New member.
(struct sframe_version_ops): Add a new argument for
mangled_ra_p.
* gas/testsuite/gas/cfi-sframe/cfi-sframe.exp: Remove test.
* gas/testsuite/gas/cfi-sframe/common-empty-4.d: Removed.
* gas/testsuite/gas/cfi-sframe/common-empty-4.s: Removed.
|
|
SFrame function info is an unsigned 8-bit field comprising of the following
(from LSB to MSB):
- 4-bits: FRE type
- 1-bit: FRE start address encoding
- 3-bits: Unused
At the moment, the most-significat 4-bits are zero (The FRE start
address encoding of SFRAME_FDE_TYPE_PCINC has a value of zero, and the upper
3-bits are unused). So the current implementation works without this patch.
To be precise, however, the fragment fixup logic is meant to fixup only the
least-significant 4-bits (i.e., only the FRE type needs to be updated
according to the function size).
This patch makes the gas implementation a bit more resilient: In the
future, when the format does evolve to make use of the currently unused
3-bits in various ways, the values in those 3-bits can be propagated
unchanged while the fragment fixup continues to update the lowermost
4-bits to indicate the selected FRE type.
ChangeLog:
* gas/gen-sframe.c (create_func_info_exp): New definition.
(output_sframe_funcdesc): Call create_func_info_exp.
* gas/sframe-opt.c (sframe_estimate_size_before_relax): The
associated fragment uses O_modulus now.
(sframe_convert_frag): Adjust the fragment fixup code according
to the new composite exp.
|
|
Once again: Old enough glibc has an (unguarded) declaration of index()
in string.h, which triggers a "shadows a global declaration" warning
with our choice of wanring level and with at least some gcc versions.
|
|
Currently supported for x86_64 and aarch64 only.
[PS: Currently, the compiler has not been adapted to generate
".cfi_sections" with ".sframe" in it. The newly added command line
option of --gsframe provides an easy way to try out .sframe support
in the toolchain.]
gas interprets the CFI directives to generate DWARF-based .eh_frame
info. These internal DWARF structures are now consumed by
gen-sframe.[ch] sub-system to, in turn, create the SFrame unwind
information. These internal DWARF structures are read-only for the
purpose of SFrame unwind info generation.
SFrame unwind info generation does not impact .eh_frame unwind info
generation. Both .eh_frame and .sframe can co-exist in an ELF file,
if so desired by the user.
Recall that SFrame unwind information only contains the minimal
necessary information to generate backtraces and does not provide
information to recover all callee-saved registers. The reason being
that callee-saved registers other than FP are not needed for stack
unwinding, and hence are not included in the .sframe section.
Consequently, gen-sframe.[ch] only needs to interpret a subset of
DWARF opcodes in gas. More details follow.
[Set 1, Interpreted] The following opcodes are interpreted:
- DW_CFA_advance_loc
- DW_CFA_def_cfa
- DW_CFA_def_cfa_register
- DW_CFA_def_cfa_offset
- DW_CFA_offset
- DW_CFA_remember_state
- DW_CFA_restore_state
- DW_CFA_restore
[Set 2, Bypassed] The following opcodes are acknowledged but are not
necessary for generating SFrame unwind info:
- DW_CFA_undefined
- DW_CFA_same_value
Anything else apart from the two above-mentioned sets is skipped
altogether. This means that any function containing a CFI directive not
in Set 1 or Set 2 above, will not have any SFrame unwind information
generated for them. Holes in instructions covered by FREs of a single
FDE are not representable in the SFrame unwind format.
As few examples, following opcodes are not processed for .sframe
generation, and are skipped:
- .cfi_personality*
- .cfi_*lsda
- .cfi_escape
- .cfi_negate_ra_state
- ...
Not processing .cfi_escape, .cfi_negate_ra_state will cause SFrame
unwind information to be absent for SFrame FDEs that contain these CFI
directives, hence affecting the asynchronicity.
x86-64 and aarch64 backends need to have a few new definitions and
functions for .sframe generation. These provide gas with architecture
specific information like the SP/FP/RA register numbers and an
SFrame-specific ABI marker.
Lastly, the patch also implements an optimization for size, where
specific fragments containing SFrame FRE start address and SFrame FDE
function are fixed up. This is similar to other similar optimizations
in gas, where fragments are sized and fixed up when the associated
symbols can be resolved. This optimization is controlled by a #define
SFRAME_FRE_TYPE_SELECTION_OPT and should be easy to turn off if needed.
The optimization is on by default for both x86_64 and aarch64.
ChangeLog:
* gas/Makefile.am: Include gen-sframe.c and sframe-opt.c.
* gas/Makefile.in: Regenerated.
* gas/as.h (enum _relax_state): Add new state rs_sframe.
(sframe_estimate_size_before_relax): New function.
(sframe_relax_frag): Likewise.
(sframe_convert_frag): Likewise.
* gas/config/tc-aarch64.c (aarch64_support_sframe_p): New
definition.
(aarch64_sframe_ra_tracking_p): Likewise.
(aarch64_sframe_cfa_ra_offset): Likewise.
(aarch64_sframe_get_abi_arch): Likewise.
(md_begin): Set values of sp/fp/ra registers.
* gas/config/tc-aarch64.h (aarch64_support_sframe_p): New
declaration.
(support_sframe_p): Likewise.
(SFRAME_CFA_SP_REG): Likewise.
(SFRAME_CFA_FP_REG): Likewise.
(SFRAME_CFA_RA_REG): Likewise.
(aarch64_sframe_ra_tracking_p): Likewise.
(sframe_ra_tracking_p): Likewise.
(aarch64_sframe_cfa_ra_offset): Likewise.
(sframe_cfa_ra_offset): Likewise.
(aarch64_sframe_get_abi_arch): Likewise.
(sframe_get_abi_arch): Likewise.
* gas/config/tc-i386.c (x86_support_sframe_p): New definition.
(x86_sframe_ra_tracking_p): Likewise.
(x86_sframe_cfa_ra_offset): Likewise.
(x86_sframe_get_abi_arch): Likewise.
* gas/config/tc-i386.h (x86_support_sframe_p): New declaration.
(support_sframe_p): Likewise.
(SFRAME_CFA_SP_REG): Likewise.
(SFRAME_CFA_FP_REG): Likewise.
(x86_sframe_ra_tracking_p): Likewise.
(sframe_ra_tracking_p): Likewise.
(x86_sframe_cfa_ra_offset): Likewise.
(sframe_cfa_ra_offset): Likewise.
(x86_sframe_get_abi_arch): Likewise.
(sframe_get_abi_arch): Likewise.
* gas/config/tc-xtensa.c (unrelaxed_frag_max_size): Add case for
rs_sframe.
* gas/doc/as.texi: Add .sframe to the documentation for
.cfi_sections.
* gas/dw2gencfi.c (cfi_finish): Create a .sframe section.
* gas/dw2gencfi.h (CFI_EMIT_sframe): New definition.
* gas/write.c (cvt_frag_to_fill): Handle rs_sframe.
(relax_segment): Likewise.
* gas/gen-sframe.c: New file.
* gas/gen-sframe.h: New file.
* gas/sframe-opt.c: New file.
|
