All,
During Connect the suggestion was made that each working group should have
its own IRC Channel for discussions and topics relating to the group in
particular (as opposed to #linaro which is 'generic' Linaro conversations).
Therefore I have just set up #linaro-tcwg on Freenode for the Toolchain
Working Group.
This channel is public and open to anyone who wants to talk with the TCWG
group about anything toolchain related.
Thanks,
Matt
--
Matthew Gretton-Dann
Toolchain Working Group, Linaro
Hi Everyone,
I have a test script from help that repeatedly builds and runs a
library under different configurations. The script includes multiple
Asan tests.
The Asan tests are producing some findings under ARM32 as shown below.
Other platforms do not include Asan findings. In addition, Valgrind
does nt produce any findings.
The test program is always built with at least -g2, and sometimes
built with -g3. However, I am not seeing the symbolication. According
to the GCC folks, asan_symbolize is not required for GCC because it
uses libbacktrace. Also see
http://bugzilla.redhat.com/show_bug.cgi?id=1250844.
Why am I lacking symbolization, and how do I achieve it?
**********
AddressSanitizer: stack-buffer-overflow on address 0xbec57b18 at pc
0x38c651 bp 0xbec579e0 sp 0xbec579e4
AddressSanitizer: stack-buffer-overflow on address 0xbedbae9c at pc
0x6553f bp 0xbedbae68 sp 0xbedbae6c
AddressSanitizer: stack-buffer-overflow on address 0xbea67b18 at pc
0x38cbc5 bp 0xbea679e0 sp 0xbea679e4
AddressSanitizer: stack-buffer-overflow on address 0xbef0fe9c at pc
0x66117 bp 0xbef0fe68 sp 0xbef0fe6c
**********
$ uname -a
Linux cubietruck 3.4.39 #35 SMP PREEMPT Tue Sep 15 17:17:33 CST 2015
armv7l armv7l armv7l GNU/Linux
$ g++ --version
g++ (Ubuntu/Linaro 4.8.2-19ubuntu1) 4.8.2
Copyright (C) 2013 Free Software Foundation, Inc.
Hi Andrew,
On 27 June 2016 at 19:32, Pinski, Andrew <Andrew.Pinski(a)cavium.com> wrote:
>> No gain expected in implementing an Ifunc'ed version of the library.
>
> How did you prove that? What hardware did you run this on to prove it?
> Also have you thought at least doing an ifunc version for 128bit atomics?
up to 64bits, the calls to the libatomic routines are inlined and
armv8.1 CAS and load-operate version are used when the application is
build for armv8.1 architecture. For 128bits, a call to the lib is
made which uses the same LL/SC implementation with or without LSE
support, as CAS and load-operate instruction don't support this data
size.
I don't have armv8.1 hardware and made the analysis on the generated
assembler. Do you have use case on your side where an ifunc version
can be useful ? I'm not aware of an algorithm which can replace
effectively LL/SC implementation with shorter CAS, do you have any
pointers ? Maybe CASP can be used in some cases, I'll investigate it.
Thanks
Yvan
> Thanks,
> Andrew
>
> -----Original Message-----
> From: linaro-toolchain [mailto:linaro-toolchain-bounces@lists.linaro.org] On Behalf Of Yvan Roux
> Sent: Monday, June 27, 2016 1:40 AM
> To: Linaro Toolchain Mailman List <linaro-toolchain(a)lists.linaro.org>
> Subject: [ACTIVITY] Week 25
>
> == Progress ==
> o Extended Validation (1/10)
> - Benchmarking job babysitting.
>
> o Upstream GCC (4/10)
> - ARMv8.1 libatomic: Analysis completed.
> No gain expected in implementing an Ifunc'ed version of the library.
> - Working on __sync buitlins potential fix.
>
> o Misc (5/10)
> * Various meetings and discussions.
> * Internal appraisal
>
> == Plan ==
> o Continue on-going tasks (__sync, benchmarking) _______________________________________________
> linaro-toolchain mailing list
> linaro-toolchain(a)lists.linaro.org
> https://lists.linaro.org/mailman/listinfo/linaro-toolchain
== Progress ==
o Extended Validation (1/10)
- Benchmarking job babysitting.
o Upstream GCC (4/10)
- ARMv8.1 libatomic: Analysis completed.
No gain expected in implementing an Ifunc'ed version of the library.
- Working on __sync buitlins potential fix.
o Misc (5/10)
* Various meetings and discussions.
* Internal appraisal
== Plan ==
o Continue on-going tasks (__sync, benchmarking)
# Progress #
* TCWG-333, ISA bit treatment in ARM thumb mode.
Got some comments from Maciej (MIPS) and need to address them.
* TCWG-518, ARM range stepping patches. [2/10]
Combine the path of "proceed" and "resume" so that we only change one
place instead of two to support range stepping. Patches are being
tested.
* TCWG-655, Workaround ARM linux kernel ptrace bug... [2/10]
by pining both program and debugger on the same core in the affected
test cases.
* Off on Wed to Fri. [6/10]
# Plan #
* Continue things above,
--
Yao
== This Week ==
* LTO (8/10)
a) TCWG-558 (2/10)
- found a way to detect if stmt is inside a loop
- addressed issue with -ffat-lto-objects
- patch posted upstream, waiting for review.
b) ipa-vrp (3/10)
- Prototype patch for propagating value ranges
inter-procedurally (accidental overlap with Kugan's patches)
- Experimented and reviewed Kugan's patch.
c) TCWG-548 (2/10)
- Wrote a pass to gather stats on external references.
- Measurements with SPEC2000 with and without prototype patch
d) Had a look at pointer alignment propagation within ipa-cp pass (1/10)
* Benchmarking (1/10)
- Obtained results for linaro-gcc-5, fsf-gcc-6 for coremark-pro for
arm-linux-gnueabihf target.
- Submitted job 112 for bkk16-buildfarm-benchmark, status shows SUCCESS, but it
appears no tcwg-benchmark job references build #112.
* Misc (1/10)
- Meetings
== Next Week ==
- Continue with TCWG-548 and ipa-vrp
- Ping patches in upstream reviews
== Progress ==
* Out of office on Monday and Tuesday [4/10]
* ARM: Do not test for CPUs, use SubtargetFeatures [TCWG-623] [4/10]
- First patch committed upstream (6 features / properties)
- Another patch in upstream review (5 features / properties)
- Working on another series of patches
* Use member initializers in ARMSubtarget [TCWG-659] [1/10]
- Trivial refactoring suggested during code review for TCWG-623
- Committed upstream
* Unbreak the selfhost bots [TCWG-661] [1/10]
- Currently bisecting the issue affecting
clang-cmake-thumbv7-full-sh (in progress)
- Tried bisecting one of the issues affecting
clang-cmake-armv7-selfhost and clang-cmake-armv7-selfhost-neon, but
the test board died in the process; Renato is trying to reproduce on
one of his boards
* Remove exit-on-error flag from CodeGen tests [TCWG-604]
- Finally committed upstream
== Plan ==
* ARM: Do not test for CPUs, use SubtargetFeatures [TCWG-623]
* Unbreak the selfhost bots [TCWG-661]
== Progress ==
* TCWG-653 Add interworking thunks to LLD
Investigated and reported upstream bug in existing implementation.
This has been fixed by reverting the change that introduced it. Got
some feedback about whether I would need to strictly follow existing
Thunk implementation.
Implemented an alternative thunk mechanism that should generalise to
supporting range extension and interworking thunks. It is passing the
existing lld regression tests.
== Plans ==
Finish off support for and add tests for ARM/Thumb interwork.
Tidy up and submit upstream.
== Progress ==
* Validation
- experimenting backport-multijob
- noticed dejagnu problems when trying to kill processes that timed out
- abe and jenkins configs patches / reviews
* Backports/snapshots
- restarted a few validations, to try to recover from disk full issues
* GCC
- neon-testgen.ml removal patch sent upstream
- PR 67591 (ARM v8 Thumb IT blocks deprecated)
- followup on vect.exp's check_vect() support for old arm cores.
- neon-fp16 tests consistency patch posted
- a couple of regressions flagged on trunk
* cortex-strings
- updated aarch64/strlen
* Support
* misc (conf-calls, meetings, emails, ....)
== Next ==
* Validation:
- patch reviews
- look at xenial, docker builders
* Backports
- restart the ones that failed due to disk space issues
* GCC
- monitor trunk regressions
- fix "check_vect" guard in gcc.dg/vect tests
- pr 67591
- advsimd tests
== Progress ==
o Extended Validation (1/10)
- Benchmarking job babysitting.
o Linaro GCC (5/10)
- Merged FSF GCtC 6 branch
- Reviewed backports (very tedious because of infra issues)
- Released June snapshots (5.4 and 6.1)
o Upstream GCC (2/10)
- ARMv8.1 libatomic: Reading and code analysis.
o Misc (2/10)
* Various meetings and discussions.
== Plan ==
o Continue on-going tasks (libatomic, benchamrking)
