Hi,
For reference, the following questions refer to a Linux 3.10 aarch64 kernel (ARMv8, ARMv8-A) compiled with Linaro 5.3-2016.02 (5.3-2016.02 arm64 CROSS_COMPILE and 5.3-2016.02 armhf CROSS32CC cross compiled from x86_64). This Linux kernel compile requires the full 64-bit tool chain plus the 32-bit gcc.
There is a Linux kernel file "arch/arm64/kernel/deprecated.c". Within that file is a block of code which is apparently designed to detect some sort of older obsolete 32-bit code. Specifically, the warning message is "Using deprecated CP15 barrier instruction". I wouldn't think that this kernel, when compiled with such a recent compiler, would ever introduce CP15 barrier code (from what I see barrier code was deprecated in ARMv7 and used to deal with obsolete ARMv6 code). Is there any chance the 32-bit 5.3 gcc would still generate CP15 barrier code?
Although this kernel and "most" modules are built with Linaro 5.3 I'd like to be able to narrow the cause down to existing binary modules not compiled with the 5.3 Linaro. If I can guarantee 5.3 32-bit gcc does not produce the CP15 barrier instruction then I'll know it is in pre-built binary modules. Can anyone tell me if C code compiled from Linaro version 5.3 32-bit gcc code would ever contain CP15 instructions?
Thanks!
What I need to confirm is if the Linaro 5.3 would generate such code from a normal block of C without any kind of asm in it? Detecting the code is part of the kernel...I need to figure out where it was generated. Is Linaro 5.3 going to generate such code without explicitly writing it in?
----- Original Message -----From: Andrew Pinski <Andrew.Pinski(a)cavium.com>To: stimits(a)comcast.net, Linaro Toolchain Mailman List <linaro-toolchain(a)lists.linaro.org>Sent: Mon, 05 Sep 2016 17:21:24 -0000 (UTC)Subject: RE: Question on "Using deprecated CP15 barrier instruction".
Simple answer is yes. There are a lot of assembly out there and someone (seen it in the past) could have used this barrier method in their code and not really thought it was going to change in the future.
Thanks,
Andrew
From: linaro-toolchain [mailto:linaro-toolchain-bounces@lists.linaro.org]On Behalf Of stimits(a)comcast.netSent: Monday, September 5, 2016 8:10 AMTo: Linaro Toolchain Mailman List <linaro-toolchain(a)lists.linaro.org>Subject: Question on "Using deprecated CP15 barrier instruction".
Hi,
For reference, the following questions refer to a Linux 3.10 aarch64 kernel (ARMv8, ARMv8-A) compiled with Linaro5.3-2016.02 (5.3-2016.02 arm64 CROSS_COMPILE and 5.3-2016.02 armhf CROSS32CC cross compiled from x86_64). This Linux kernel compile requires the full 64-bit tool chain plus the 32-bit gcc.
There is a Linux kernel file "arch/arm64/kernel/deprecated.c". Within that file is a block of code which is apparently designed to detect some sort of older obsolete 32-bit code. Specifically, the warning message is "Using deprecated CP15 barrier instruction". I wouldn't think that this kernel, when compiled with such a recent compiler, would ever introduce CP15 barrier code (from what I see barrier code was deprecated in ARMv7 and used to deal with obsolete ARMv6 code). Is there any chance the 32-bit 5.3 gcc would still generate CP15 barrier code?
Although this kernel and "most" modules are built with Linaro 5.3 I'd like to be able to narrow the cause down to existing binary modules not compiled with the 5.3 Linaro. If I can guarantee 5.3 32-bit gcc does not produce the CP15 barrier instruction then I'll know it is in pre-built binary modules. Can anyone tell me if C code compiled from Linaro version 5.3 32-bit gcc code would ever contain CP15 instructions?
Thanks!
== Progress ==
o Linaro GCC/Validation (7/10)
- Merged bkk16 buildfarm developments into main job.
- Backports: Reviews, dependencies tracking and backports.
- Analysed extended validation results.
o Misc (3/10)
* Various meetings and discussions.
== Plan ==
o Release 2016.09 Snapshots
o GNU Cauldron
== Progress ==
- IPA-VRP: Re-based ipa-cp/ipa-prop on top of Prathameshes commit
(quite a few conflicts) and did full testing before posting to the
list. Patch approved for commit.
- Waiting for Early-VRP patch to commit rest of the patches in the series
- All other patches are OK now.
- Looking at tree-vrp in details. Created
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77387
- Looking at re-assoc wrong code generation issue (PR72835). Posted
another attempt to fix for review
= Next ==
- Work on tree-vrp improvements
- Follow up on pending patches
== This Week ==
* TCWG-779 (4/10)
- Upstream patch iterations
* NULL pointer propagation in ipa-bitwise-cp (4/10)
- WIP patch
* Benchmarking (1/10)
- Found how to set iterations for coremark
- Submitted job for setting up hack session on Juno
* Misc (1/10)
- Meetings
== Next Week ==
- NULL pointer propagation
- TCWG-779
- GNU Cauldron
* Holiday on Monday. [2/10]
# Progress #
* TCWG-685, GDB 7.12 release. No new issue. [1/10]
* TCWG-655, ARM linux kernel ptrace bug. [3/10]
Teach GDB testsuite to detect such kernel bug, and skip all tests
related to floating point. Patches are committed.
On the other hand, upgrade my arm kernel to 4.7.2, on which the ptrace
bug is fixed.
* TCWG-518, range stepping on ARM. [2/10].
Turned it on, but it causes some threads starvation. Investigating.
* Finish the reproducer to show odd behaviour of armv8 kernel in si_code
after PTRACE_SINGLESTEP and Will Deacon fixed it
http://lists.infradead.org/pipermail/linux-arm-kernel/2016-September/453289…
[1/10]
* Think about the GDB plan, and write down a list of things I need to
do. [1/10]
# Plan #
* TCWG-685, TCWG-518.
* GNU Cauldron.
--
Yao Qi
== Activity ==
[TCWG-610] Sent .ARM.exidx for upstream review.
Will need to rework and simplify bit to make more specific to ARM. In
summary abandon pretence of SHF_LINK_ORDER in general and concentrate
on supporting its one known use case in .ARM.exidx sections.
Made a couple of drafts of forthcoming LLVM Cauldron presentation
- Presented locally
- Modified slides after overrunning time
== Plans ==
[TCGWG-610] Rework and resend for review
llvm-cauldron on Thursday
Intending to take Friday as holiday to take advantage of visiting
parents whilst up North.
== Progress ==
* Validation
- patch reviews (Jenkins jobs, abe) mainly for the release process
* Backports
- resubmitted the pending ones
- started looking at v8.2 backports
* GCC
- resumed PR 67591 (ARM v8 Thumb IT blocks deprecated)
* arm-neon-tests
- small update to support clang, as requested by Chromium
* misc (conf-calls, meetings, emails, ....)
- catching up after holidays
== Next ==
- monitor trunk regressions
- pr 67591
- release scripts
- backports
== Progress ==
o Linaro GCC/Validation (7/10)
- Reviewed on-going Backports.
- Analysis on remaining backports dependencies on-going.
- Merged FSF GCC 6 branch.
- Last FSF GCC 4.9 merge still on-going (some conflicts to solve).
- Defining and experimenting new revisions/backports tracking
format in yaml.
o Misc (3/10)
* Various meetings and discussions.
== Plan ==
o FInish backports, and FSF branch merge for next week snapshot.
== This Week ==
* TCWG-666 (2/10)
- Martin confirmed the assert was spurious that caused some obj-c tests to fail,
removing it passes bootstrap+test.
- Changed option name to -fipa-bit-cp following Honza's suggestion
- Committed as r239769.
* TCWG-779 (4/10)
- Patch iterations based on upstream suggestions.
* Public Holiday (2/10)
* Misc (2/10)
- Background reading on mod/ref analysis
- Meetings
# Progress #
* TCWG-685, GDB 7.12 release. [4/10]
Finish all native testing on ARM. Triaged tests result. Only find
one fail that test assumes HW watchpoint is always available.
Reported it upstream, but need more thoughts on how to fix it.
Both AArch64 and ARM GDB is in a good state, in terms of test results.
* TCWG-533, Remove global variable arm_override_mode. [2/10]
It is paused by 7.12 release, and work on it again. 10 patches are
ready. Being regression tested.
* Analyse the kernel behaviour on single step over fork. [4/10]
Upgrade juno kernel to 4.7.0-rc4+, and verified Will Deacon's patch.
http://lists.infradead.org/pipermail/linux-arm-kernel/2016-August/451711.ht…
With the patch, GDB can correctly single step over fork, however,
GDB is still broken if there is a breakpoint. Write a small
reproducer, but doesn't trigger the problem. It might be a GDB bug
or kernel bug.
# Plan #
* Resume works interrupted by 7.12 release.
--
Yao Qi
== Progress ==
- Got back from Sabbatical and caught up with email/events
- TCWG-610 Support for ARM Exceptions in lld.
Implemented support for SHF_LINK_ORDER and .ARM.exidx in lld, have
this working and tested for
images (both with default and linker scripts) and relocatable ld -r
with the default layout. Currently it looks like relocatable outputs
with linker scripts aren't working at all right now.
== Plan ==
- Hope to send to upstream review next week.
- Write the first pass of the LLVM Cauldron presentation.
== Planned absence ==
Monday 29th August is UK national holiday
== Progress ==
* [AArch64] Support for label arithmetic in the assembler [TCWG-710] [9/10]
- Patch in upstream review
- While adding more tests for the patch above, I noticed that we're not
encoding the lsl #12 on add/sub immediates correctly
- Submitted a patch to fix that as well
* Misc [1/10]
- Ran more precommit tests for last week's reverted revisions
== Plan ==
* Handle special cases in AArch64InstrInfo::GetInstSizeInBytes [TCWG-757]
* Two days off [4/10]
# Progress #
* TCWG-685, GDB 7.12 release. [3/10]
Fix one bug that AArch64 GDB doesn't recognize new "STP with base register"
instruction in prologue. Recent GCC
https://gcc.gnu.org/ml/gcc-patches/2016-07/msg01933.html
starts to generate that instruction in prologue. Fix it in both
master and 7.12.
Successfully build armhf toolchain with latest gcc/glibc. Run GDB
tests with the new toolchain. Test results are OK, except fails when
tests are compiled with -march=cortex-a15. It isn't a release
blocker. Open TCWG-756 for it and will look into these fails later.
* GDBserver build failure. [1/10]
Review the patch fixing GDBserver build failure with latest glibc.
Patch is OK, but make sure it can be merged to master/7.12/7.11, as
we are still using GDB 7.11.
* Prelink. [1/10]
prelink causes some GDB tests failures, so I look at it. prelink
isn't active, because I can't see any mails in archive since 2013.
ARM is supported, but AArch64 isn't.
* Misc, [1/10].
Set up email 2fa.
# Plan #
* GDB 7.12 release.
* Upgrade the linux kernel on my juno board.
--
Yao Qi
== Progress ==
* LLVM 3.9.0 Release for AArch64 [TCWG-696] [1/10]
- Ran the tests for RC2, everything looks good on AArch64
* [AArch64] Support for label arithmetic in the assembler [TCWG-710] [3/10]
- This is starting to look like a patch, but I need to add more tests
* Buildbot babysitting [TCWG-716, 719, 720] [5/10]
- Bisected a number of failures and reverted some patches
- Ran precommit tests for 2 different issues; one of them has passed with the
author's fix, the other one hasn't, so I'll probably have to help figure out
what the problem is
* Set up a BeagleBoard so I can run some tests for TCWG-674 [1/10]
== Plan ==
* [AArch64] Support for label arithmetic in the assembler [TCWG-710]
- Send a patch upstream
* Run more precommits if necessary
o one day off (2/10)
== Progress ==
o Linaro GCC/Validation (3/10)
- Continuing Backports.
- Prepared branch merges
- AArch64 builders stable again after Jenkins upgrade.
- Investigated GDB build failure with Glibc trunk, Adhemerval
patch accepted upstream.
- start to merge Bkk16-buildfarm job into main buildfarm one.
o Upstream GCC (1/10)
- Guality fix: more investigation .
o Misc (4/10)
* Various meetings and discussions.
* Another Internal support.
== Plan ==
o Continue on backports, and FSF branch merge, etc
Hi,
I was able to get linaro-6.1-2016.07 compiled for both aarch64 and armhf. I also have some prebuilt 5.2 and 5.3 binaries, plus a few other 4.8 and 4.9 compilers from quite some time back. I've used these for building a Linux 3.10 kernel, and the newer linaro-6.1 fails during kernel compile. The issue seems to be the assembler does not recognize option "-EL" (all of the ARM systems I'm building for are little endian, I've not seen a big endian system).
I am wondering if support for options "-EB" and "-EL" are part of the configure options? There is the generic "help" listing the "--enable-FEATURE=ARG", but I do not see a comprehensive list of features this might deal with. I'm hoping that big/little endian for armhf and aarch64 can be enabled with this. Otherwise I'm hoping to find more information on what I might need to do or change for compatibility with the "-EL" option.
For reference, I have similar templates for 32-bit and 64-bit configuration (different triplet and build root). Here's one:
export SRC='/home/build/linaro/gcc-linaro-snapshot-6.1-2016.07'export BUILD='/home/build/linaro/32bit'export TRIPLET=arm-linux-gnueabihfexport CLONE=/usr/local/sysroot/${TRIPLET}export VENDOR_ID=gcc-linaro-6.1-2016.07export LINUX_ARCH=armhf cd $BUILD${SRC}/configure --prefix=/usr/local/${TRIPLET}/${VENDOR_ID} --target=${TRIPLET} \ --with-build-sysroot=${CLONE} \ --enable-languages=c \ --with-sysroot=/
Thanks!
Hi,
In a previous thread some sysroot issues were resolved, and I am able to build cross-compilers under gcc-linaro-snapshot-6.1-2016.07 for languages c, c++, and objc. My sysroot consisted of a loopback mounted dd copy of an Ubuntu 14.04 file system for aarch64. That particular file system runs on a quad core Cortex-A57, and is fully capable of compiling many different types of software (the file system is set up for development). The successful configuration was like this (configuration and compile was from an independent directory not in the source tree):
export SRC='/home/build/linaro/gcc-linaro-snapshot-6.1-2016.07'export TRIPLET=aarch64-linux-gnuexport CLONE=/usr/local/sysroot/${TRIPLET}export VENDOR_ID=gcc-linaro-6.1-2016.07export LINUX_ARCH=arm64
${SRC}/configure --prefix=/usr/local/${TRIPLET}/${VENDOR_ID} --target=${TRIPLET} \ --with-build-sysroot=${CLONE} \ --enable-languages=c,c++,objc \ --with-sysroot=/
Now I also need armhf (I must support both 32-bit and 64-bit), so I'm trying to figure out host and sysroot differences (I have been unable to get armhf to compile). The configuration is basically this variation of the above, plus some sysroot additional support:
export SRC='/home/build/linaro/gcc-linaro-snapshot-6.1-2016.07'export TRIPLET=arm-linux-gnueabihfexport CLONE=/usr/local/sysroot/${TRIPLET}export VENDOR_ID=gcc-linaro-6.1-2016.07export LINUX_ARCH=armhf ${SRC}/configure --prefix=/usr/local/${TRIPLET}/${VENDOR_ID} --target=${TRIPLET} \ --with-build-sysroot=${CLONE} \ --enable-languages=c \ --with-sysroot=/
Note that for testing purposes I tried to compile only languages of c, c++, and objc, each one at a time instead of together. Errors do not differ in any way for picking of any of those three languages. I also have a complete Ubuntu 14.04 file system for armhf which is fully equipped for building of each of those languages, and is perhaps in some ways more complete as a development environment than the previously successful aarch64 file system (the sysroot runs on a quad core Cortex-A15). I tried this purely armhf file system as the sysroot to rule out incorrect multiarch support, and the error did not change. I am guessing the issue is not the sysroot, but I wanted to verify this since there may be other requirements for armhf instead of aarch64.
I am at a loss though to explain why the host would be at issue since it appears all prerequisites were met and I had success with aarch64.
The details of the error seem to always occur in libcc1 build. I see this in the libcc1/config.log as the failure regardless of sysroot or supported language, and only while building for armhf:
configure:14569: checking for -rdynamicconfigure:14579: result: yesconfigure:14589: checking for library containing dlopenconfigure:14620: gcc -o conftest -g -O2 conftest.c >&5/tmp/ccyhVkpp.o: In function `main':/home/build/linaro/objdir/libcc1/conftest.c:38: undefined reference to `dlopen'collect2: error: ld returned 1 exit statusconfigure:14620: $? = 1configure: failed program was:| /* confdefs.h */| #define PACKAGE_NAME "libcc1"| #define PACKAGE_TARNAME "libcc1"| #define PACKAGE_VERSION "version-unused"| #define PACKAGE_STRING "libcc1 version-unused"| #define PACKAGE_BUGREPORT ""| #define PACKAGE_URL ""| #define STDC_HEADERS 1| #define HAVE_SYS_TYPES_H 1| #define HAVE_SYS_STAT_H 1| #define HAVE_STDLIB_H 1| #define HAVE_STRING_H 1| #define HAVE_MEMORY_H 1| #define HAVE_STRINGS_H 1| #define HAVE_INTTYPES_H 1| #define HAVE_STDINT_H 1| #define HAVE_UNISTD_H 1| #define __EXTENSIONS__ 1| #define _ALL_SOURCE 1| #define _GNU_SOURCE 1| #define _POSIX_PTHREAD_SEMANTICS 1| #define _TANDEM_SOURCE 1| #define HAVE_DLFCN_H 1| #define LT_OBJDIR ".libs/"| #define HAVE_DECL_BASENAME 1| /* end confdefs.h. */
Are there different host requirements when building armhf versus aarch64 which might explain why dlopen is not found? FYI, both development and other support for dlopen exists already on the system, so the failure to find dlopen is not for lack of host support (related dlopen files all seem to be present on all tested sysroots as well, both as armhf and aarch64). Is this a sysroot issue, a host issue, or a configure issue?
Thanks!
== Progress ==
o Linaro GCC/Validation (3/10)
- Backports: tracking missing dependencies.
- Looked at our AArch64 builder issues, reproduced the problem.
o Upstream GCC (3/10)
- Found a fix for guality tests failures, analyzing all the test
case which can be impacted.
o Misc (4/10)
* Various meetings and discussions.
* Internal support on GCC
== Plan ==
o Continue on backports, and FSF branch merge
o Finalize and submit on-going patches
Hi,
I've been trying to build the c and c++ cross-compiler for triplet aarch64-linux-gnu (--target=aarch64-linux-gnu --enable-languages=c,c++) on snapshot for 6.1-2016.07, and cannot get past this:
cc1: error: no include path in which to search for stdc-predef.h From what I can tell this may already be a known bug inherited from back in the days of Linaro 4.8. I tried various ways around this, such as trying to create an empty stdc-predef.h in various locations, but always ended up either not fixing the issue or breaking something else even sooner. Is there a simple way around this on the configure command line? If not, is there some recommended edit for this?
Thanks!
== Progress ==
* Refactor SelectionDAGBuilder::visitInlineAsm [TCWG-643] [1/10]
- Incorporated some review feedback and committed the patch upstream
* [AArch64] Support for label arithmetic in the assembler [TCWG-710] [4/10]
- Most of the support seems to be there, but the error checking is
too aggressive and it rejects cases that could in fact be handled by
the assembler
- Trying to figure out exactly what the assembler can currently
handle and how to relax the error checking accordingly
* [AArch64] Keep merging consecutive stores in store sequences [TCWG-704] [2/10]
- Fixing this might slow down the compiler more than the optimization is worth
- Got some debug dumps on the test-suite to see how often sequences
of consecutive stores show up
* Misc [3/10]
- Booked trip to Cambridge / Hebden Bridge
- Buildbot babysitting (2 nasty selfhost failures), code reviews,
LLVM Cauldron
== Plan ==
* [AArch64] Support for label arithmetic in the assembler [TCWG-710]
* [AArch64] Keep merging consecutive stores in store sequences [TCWG-704]
# Progress #
* TCWG-685, GDB 7.12 release. [4/10]
Triaged all aarch64 native test results. Two patches fixing heap overflow
are posted. The new C++11 ABI tag makes troubles to some gdb.cp tests.
Rebuild armhf toolchain for GDB arm native test. glibc failed to build due
to "gperf" is not found.
* AArch64 OpenOCD investigation. Done. [2/10]
Write a report. In general, there was a patch for AArch64 OpenOCD, but
some issues should be addressed before it can be merged to mainline.
* Interview in US Embassy, and file expense. [2/10]
* Misc, meetings, [2/10]
# Plan #
* TCWG-685, GDB 7.12 release.
Build recent native armhf toolchain, and test gdb 7.12 with it.
Bug fixes if needed.
* Off on Wed and Thu.
--
Yao Qi
== This Week ==
* LTO (6/10)
a) TCWG-666 (5/10)
- Patch iterations based on suggestions from Honza and Martin
- Honza approved patch, however I see some failures during bootstrap+test,
submitted patch to address those.
b) TCWG-548 (1/10)
- Benchmarking SPEC2006 on my chromebook cancelled midway due
to issues with chromebook.
- Setting up hacking session on juno-01 with help from Maxim
- Analyzing SPEC2k results.
* TCWG-72 (1/10)
- Submitted patch upstream to set NULL for sdivmod_optab entry in optabs.def
* Bugs (2/10)
- Committed fix for fallouts caused by previous patches
- TCWG-700: Patch iterations based on upstream discussion
* Misc (1/10)
- Meetings
== Next Week ==
- Holidays