[PATCH,RFC,V4 0/8] Definition and Implementation of CTF Frame format
Indu Bhagat
indu.bhagat@oracle.com
Mon Jun 27 23:47:11 GMT 2022
Hi,
This is version 4 of the previously sent RFC series.
Initial (V1) posting contains necessary introductions:
https://sourceware.org/pipermail/binutils/2022-May/120731.html
V2 posting with some improvements:
https://sourceware.org/pipermail/binutils/2022-May/120899.html
V3 posting with further improvements:
https://sourceware.org/pipermail/binutils/2022-June/121245.html
The commit log of each patch in the current patch series specifies the changes
from the version V3 of the respective patch. Briefly, following are the main
changes in the current version V4 as compared to V3:
1. CTF Frame format can now compactly represent unwind information for regular,
repetitive instruction patterns like the plt entries. This has helped make
the size of .ctf_frame more attractive. [As .ctf_frame encodes a subset of
information in .eh_frame, the sizes of .eh_frame will be justifiably higher.]
ratio = (.ctf_frame size) / (.eh_frame size + .eh_frame_hdr size)
Program | ratio
----------------
addr2line | .76
as | .81
elfedit | .76
gdb | .78
gdbserver | .78
gprof | .80
ld | .81
nm | .78
objdump | .81
readelf | .82
strings | .76
ar | .78
c++filt | .75
gprofng | .59
ld.bfd | .81
objcopy | .81
ranlib | .78
size | .76
strip | .81
In summary, earlier the CTF Frame unwind information for plt entires looked
like follows (in V3).
$ readelf --ctf-frame=.ctf_frame testbinary
...
func idx [0]: pc = 0x401020, size = 64 bytes
STARTPC CFA FP RA
0000000000401020 sp+16 u u
0000000000401026 sp+24 u u
0000000000401030 sp+8 u u
000000000040103b sp+16 u u
0000000000401040 sp+8 u u
000000000040104b sp+16 u u
0000000000401050 sp+8 u u
000000000040105b sp+16 u u
Now with the V4 version of the patch series:
func idx [0]: pc = 0x401020, size = 16 bytes
STARTPC CFA FP RA
0000000000401020 sp+16 u u
0000000000401026 sp+24 u u
func idx [1]: pc = 0x401030, size = 48 bytes
STARTPC[m] CFA FP RA
0000000000000000 sp+8 u u
000000000000000b sp+16 u u
2. More testcases in libctfframe, further improvements and bugfixes.
This is a work in progress. In the subsequent iterations of the series, I plan
to focus on further testing CTF Frame unwind information for correctness and
completeness. We currently have a suite of unwinder tests which are used to
validate the CTF Frame unwind information in various scenarios on x86_64 and
aarch64 by unwinding through a variety of call stacks. We will now work on
increasing the coverage of those tests and incorporating the testsuite (perhaps
with libctfbacktrace) in the next patch series.
That said, CTF Frame support V4 patch series has been regression tested on a
host of targets with no regressions.
Important note: libctfframe/configure has NOT been included in the patch
series, as it causes the size of some patches to go beyond the allowed limit.
Please regenerate the libctfframe/configure after applying the series.
Please comment and provide feedback, it will help shape the format. At this
time, I really need some inputs on:
1. What is a good place for an unwinder based on CTF Frame format ? Currently
to facilitate discussion, it is presented in a library of its own:
libctfbacktrace which, in turn, uses the libctfframe library for decoding the
.ctf_frame section for unwinding. We brainstormed a bit about the possible
candidates being libbacktace, libgcc or libunwind ? Are there any
recommendations ?
Thanks,
Indu Bhagat (6):
ctf-frame.h: Add CTF Frame format definition
gas: add new command line option --gctf-frame
gas: generate .ctf_frame
bfd: linker: merge .ctf_frame sections
readelf/objdump: support for CTF Frame section
gdb: sim: buildsystem changes to accommodate libctfframe
Weimin Pan (2):
libctfframe: add the CTF Frame library
unwinder: generate backtrace using CTF Frame format
Makefile.def | 5 +
Makefile.in | 1289 +++++++++++++-
bfd/Makefile.am | 6 +-
bfd/Makefile.in | 7 +-
bfd/bfd-in2.h | 1 +
bfd/configure | 2 +-
bfd/configure.ac | 2 +-
bfd/elf-bfd.h | 55 +
bfd/elf-ctf-frame.c | 529 ++++++
bfd/elf.c | 32 +
bfd/elf64-x86-64.c | 97 +-
bfd/elflink.c | 52 +
bfd/elfxx-x86.c | 379 +++-
bfd/elfxx-x86.h | 46 +
bfd/section.c | 1 +
binutils/Makefile.am | 10 +-
binutils/Makefile.in | 10 +-
binutils/doc/binutils.texi | 4 +
binutils/doc/ctfframe.options.texi | 10 +
binutils/objdump.c | 76 +
binutils/readelf.c | 47 +
config/ctf-frame.m4 | 16 +
configure | 2 +-
configure.ac | 2 +-
gas/Makefile.am | 3 +
gas/Makefile.in | 23 +-
gas/as.c | 10 +-
gas/as.h | 13 +-
gas/config/tc-aarch64.c | 42 +
gas/config/tc-aarch64.h | 29 +
gas/config/tc-i386.c | 46 +
gas/config/tc-i386.h | 26 +
gas/config/tc-xtensa.c | 1 +
gas/ctf-frame-opt.c | 158 ++
gas/doc/as.texi | 19 +-
gas/dw2gencfi.c | 30 +
gas/dw2gencfi.h | 1 +
gas/gen-ctf-frame.c | 1242 +++++++++++++
gas/gen-ctf-frame.h | 142 ++
gas/testsuite/gas/cfi-ctf/cfi-ctf-aarch64-1.d | 20 +
gas/testsuite/gas/cfi-ctf/cfi-ctf-aarch64-1.s | 61 +
gas/testsuite/gas/cfi-ctf/cfi-ctf-common-1.d | 17 +
gas/testsuite/gas/cfi-ctf/cfi-ctf-common-1.s | 3 +
gas/testsuite/gas/cfi-ctf/cfi-ctf-common-2.d | 17 +
gas/testsuite/gas/cfi-ctf/cfi-ctf-common-2.s | 2 +
gas/testsuite/gas/cfi-ctf/cfi-ctf-common-3.d | 17 +
gas/testsuite/gas/cfi-ctf/cfi-ctf-common-3.s | 4 +
gas/testsuite/gas/cfi-ctf/cfi-ctf-x86_64-1.d | 22 +
gas/testsuite/gas/cfi-ctf/cfi-ctf-x86_64-1.s | 30 +
gas/testsuite/gas/cfi-ctf/cfi-ctf.exp | 48 +
gas/write.c | 13 +
gdb/Makefile.in | 8 +-
gdb/acinclude.m4 | 4 +-
gdb/configure | 35 +-
gdb/configure.ac | 11 +
include/ctf-backtrace-api.h | 57 +
include/ctf-frame-api.h | 213 +++
include/ctf-frame.h | 281 +++
include/elf/common.h | 1 +
include/elf/internal.h | 1 +
ld/Makefile.am | 2 +
ld/Makefile.in | 2 +
ld/configure | 8 +-
ld/configure.ac | 3 +
ld/ld.texi | 4 +-
ld/scripttempl/elf.sc | 2 +
ld/testsuite/ld-aarch64/aarch64-elf.exp | 2 +
ld/testsuite/ld-aarch64/ctf-frame-bar.s | 7 +
ld/testsuite/ld-aarch64/ctf-frame-foo.s | 10 +
ld/testsuite/ld-aarch64/ctf-frame-simple-1.d | 26 +
ld/testsuite/ld-bootstrap/bootstrap.exp | 8 +-
ld/testsuite/ld-ctf-frame/ctf-frame-empty.d | 10 +
ld/testsuite/ld-ctf-frame/ctf-frame-empty.s | 2 +
ld/testsuite/ld-ctf-frame/ctf-frame.exp | 47 +
ld/testsuite/ld-ctf-frame/discard.d | 10 +
ld/testsuite/ld-ctf-frame/discard.ld | 9 +
ld/testsuite/ld-ctf-frame/discard.s | 13 +
ld/testsuite/ld-x86-64/ctf-frame-bar.s | 31 +
ld/testsuite/ld-x86-64/ctf-frame-foo.s | 37 +
ld/testsuite/ld-x86-64/ctf-frame-plt-1.d | 29 +
ld/testsuite/ld-x86-64/ctf-frame-simple-1.d | 35 +
ld/testsuite/ld-x86-64/x86-64.exp | 2 +
ld/testsuite/lib/ld-lib.exp | 45 +
libctfframe/Makefile.am | 84 +
libctfframe/Makefile.in | 1050 +++++++++++
libctfframe/aclocal.m4 | 1242 +++++++++++++
libctfframe/config.h.in | 144 ++
libctfframe/configure.ac | 82 +
libctfframe/ctf-backtrace-err.c | 46 +
libctfframe/ctf-backtrace.c | 617 +++++++
libctfframe/ctf-frame-dump.c | 181 ++
libctfframe/ctf-frame-error.c | 49 +
libctfframe/ctf-frame-impl.h | 55 +
libctfframe/ctf-frame.c | 1584 +++++++++++++++++
libctfframe/testsuite/config/default.exp | 60 +
libctfframe/testsuite/lib/ctfframe-lib.exp | 206 +++
.../testsuite/libctfframe.decode/DATA1 | Bin 0 -> 59 bytes
.../testsuite/libctfframe.decode/DATA2 | Bin 0 -> 91 bytes
.../testsuite/libctfframe.decode/DATA_BIGE | Bin 0 -> 59 bytes
.../libctfframe.decode/bigendian_data.c | 110 ++
.../libctfframe.decode/bigendian_data.lk | 3 +
.../testsuite/libctfframe.decode/decode.exp | 38 +
.../testsuite/libctfframe.decode/frecnt_1.c | 108 ++
.../testsuite/libctfframe.decode/frecnt_1.lk | 3 +
.../testsuite/libctfframe.decode/frecnt_2.c | 113 ++
.../testsuite/libctfframe.decode/frecnt_2.lk | 3 +
.../testsuite/libctfframe.encode/encode.exp | 38 +
.../testsuite/libctfframe.encode/encode_1.c | 173 ++
.../testsuite/libctfframe.encode/encode_1.lk | 3 +
libctfframe/ttest.c | 78 +
sim/common/Make-common.in | 7 +-
111 files changed, 11693 insertions(+), 58 deletions(-)
create mode 100644 bfd/elf-ctf-frame.c
create mode 100644 binutils/doc/ctfframe.options.texi
create mode 100644 config/ctf-frame.m4
create mode 100644 gas/ctf-frame-opt.c
create mode 100644 gas/gen-ctf-frame.c
create mode 100644 gas/gen-ctf-frame.h
create mode 100644 gas/testsuite/gas/cfi-ctf/cfi-ctf-aarch64-1.d
create mode 100644 gas/testsuite/gas/cfi-ctf/cfi-ctf-aarch64-1.s
create mode 100644 gas/testsuite/gas/cfi-ctf/cfi-ctf-common-1.d
create mode 100644 gas/testsuite/gas/cfi-ctf/cfi-ctf-common-1.s
create mode 100644 gas/testsuite/gas/cfi-ctf/cfi-ctf-common-2.d
create mode 100644 gas/testsuite/gas/cfi-ctf/cfi-ctf-common-2.s
create mode 100644 gas/testsuite/gas/cfi-ctf/cfi-ctf-common-3.d
create mode 100644 gas/testsuite/gas/cfi-ctf/cfi-ctf-common-3.s
create mode 100644 gas/testsuite/gas/cfi-ctf/cfi-ctf-x86_64-1.d
create mode 100644 gas/testsuite/gas/cfi-ctf/cfi-ctf-x86_64-1.s
create mode 100644 gas/testsuite/gas/cfi-ctf/cfi-ctf.exp
create mode 100644 include/ctf-backtrace-api.h
create mode 100644 include/ctf-frame-api.h
create mode 100644 include/ctf-frame.h
create mode 100644 ld/testsuite/ld-aarch64/ctf-frame-bar.s
create mode 100644 ld/testsuite/ld-aarch64/ctf-frame-foo.s
create mode 100644 ld/testsuite/ld-aarch64/ctf-frame-simple-1.d
create mode 100644 ld/testsuite/ld-ctf-frame/ctf-frame-empty.d
create mode 100644 ld/testsuite/ld-ctf-frame/ctf-frame-empty.s
create mode 100644 ld/testsuite/ld-ctf-frame/ctf-frame.exp
create mode 100644 ld/testsuite/ld-ctf-frame/discard.d
create mode 100644 ld/testsuite/ld-ctf-frame/discard.ld
create mode 100644 ld/testsuite/ld-ctf-frame/discard.s
create mode 100644 ld/testsuite/ld-x86-64/ctf-frame-bar.s
create mode 100644 ld/testsuite/ld-x86-64/ctf-frame-foo.s
create mode 100644 ld/testsuite/ld-x86-64/ctf-frame-plt-1.d
create mode 100644 ld/testsuite/ld-x86-64/ctf-frame-simple-1.d
create mode 100644 libctfframe/Makefile.am
create mode 100644 libctfframe/Makefile.in
create mode 100644 libctfframe/aclocal.m4
create mode 100644 libctfframe/config.h.in
create mode 100644 libctfframe/configure.ac
create mode 100644 libctfframe/ctf-backtrace-err.c
create mode 100644 libctfframe/ctf-backtrace.c
create mode 100644 libctfframe/ctf-frame-dump.c
create mode 100644 libctfframe/ctf-frame-error.c
create mode 100644 libctfframe/ctf-frame-impl.h
create mode 100644 libctfframe/ctf-frame.c
create mode 100644 libctfframe/testsuite/config/default.exp
create mode 100644 libctfframe/testsuite/lib/ctfframe-lib.exp
create mode 100644 libctfframe/testsuite/libctfframe.decode/DATA1
create mode 100644 libctfframe/testsuite/libctfframe.decode/DATA2
create mode 100644 libctfframe/testsuite/libctfframe.decode/DATA_BIGE
create mode 100644 libctfframe/testsuite/libctfframe.decode/bigendian_data.c
create mode 100644 libctfframe/testsuite/libctfframe.decode/bigendian_data.lk
create mode 100644 libctfframe/testsuite/libctfframe.decode/decode.exp
create mode 100644 libctfframe/testsuite/libctfframe.decode/frecnt_1.c
create mode 100644 libctfframe/testsuite/libctfframe.decode/frecnt_1.lk
create mode 100644 libctfframe/testsuite/libctfframe.decode/frecnt_2.c
create mode 100644 libctfframe/testsuite/libctfframe.decode/frecnt_2.lk
create mode 100644 libctfframe/testsuite/libctfframe.encode/encode.exp
create mode 100644 libctfframe/testsuite/libctfframe.encode/encode_1.c
create mode 100644 libctfframe/testsuite/libctfframe.encode/encode_1.lk
create mode 100644 libctfframe/ttest.c
--
2.31.1
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