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.
Add a new test plt-findfre-1 to ensure lookup of SFrame stack trace
information for pltN entries is correct.
In this test, a dummy SFrame FDE of type SFRAME_FDE_TYPE_PCMASK is
created. The size of the 'function code block' covered by the SFrame
FDE is equivalent to 5 pltN entries of 16 bytes each.
The test first looks up SFrame FREs for some addresses in the first pltN
entry, followed by lookups for some addresses in the fourth pltN entry.
libsframe/
* Makefile.in: Regenerated.
* testsuite/libsframe.find/find.exp: Add new test.
* testsuite/libsframe.find/local.mk: Likewise.
* testsuite/libsframe.find/plt-findfre-1.c: New test.
sframe_get_funcdesc_with_addr API is currently used internally by the
sframe_find_fre ().
In this test, we create three dummy SFrame FDEs with 4 FREs each. Then,
we use few negative tests to lookup FREs with PCs not in the range of
PCs covered by the FDEs, ensuring graceful return from
sframe_get_funcdesc_with_addr in all cases. Some positive tests are
also added that exercise further scenarios as well.
libsframe/
* Makefile.in: Regenerated.
* testsuite/libsframe.find/find.exp: Include new test.
* testsuite/libsframe.find/findfunc-1.c: New Test.
* testsuite/libsframe.find/local.mk: Include new test.
libsframe provides an API to find the FRE associated with a given PC in
the program. This patch adds a direct test of this API.
In this test, we create two dummy SFrame FDEs with 4 FREs each. Then we
test that sframe_find_fre () works for the first, second, third and the
last FRE from one of the FDEs. Such a test ensures better regression
testing for the sframe_find_fre () function which is going to be the
bread and butter of an SFrame based stack tracer.
libsframe/
* Makefile.in: Regenerated.
* testsuite/libsframe.find/find.exp: New test.
* testsuite/libsframe.find/findfre-1.c: New test.
* testsuite/libsframe.find/local.mk: Build new test.
* testsuite/local.mk: Include libsframe.find.
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.
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.
