Hi Alexandros,
Could you use the linaro-toolchain list for stuff like this please?
You're more likely to find somebody who knows the answer that way.
I'm pretty sure the problem is not the compiler because, as far as I can
see, both architectures' compilers emit ".weak" directives. If there is
a problem, I'd say it's in the linker.
Your test case gives two different addresses on Lucid x86, and on ARM
(so you say, I've not tested it), but the same address twice on Precise.
This is a surprising result. *I* would have expected that static values
in different dlopen'd libraries would not be unified, but apparently
they are ... somtimes.
I'm afraid I don't really have any insight here. :(
Anyway, regardless of whether one is correct, or not, I'd suggest *not*
relying on this behaviour - it's clearly not portable. I say leave it at
arm's length in production software for a few years.
Andrew
On 06/03/12 14:27, Alexandros Frantzis wrote:
> On Tue, Mar 06, 2012 at 09:51:01AM +0800, Sam Spilsbury wrote:
>> On Mon, Mar 5, 2012 at 11:50 PM, Alexandros Frantzis
>> <alexandros.frantzis(a)linaro.org> wrote:
>>> Hi all,
>>>
>>> this is an update on my progress with the updated compiz branches.
>>>
>>> I have been trying to run our update compiz branches
>>> (compiz-*/linaro-gles2-update) on ARM (precise armhf), but I have stumbled onto
>>> the same issue Marc reported some days ago. In particular, I get:
>>>
>>> /usr/bin/compiz (core) - Fatal: Private index value "15CompositeWindow_index_4" already stored in screen.
>>> /usr/bin/compiz (core) - Fatal: Private index value "15CompositeScreen_index_4" already stored in screen.
>>>
>>> and then a segfault when I try to run compiz.
>>>
>>> Note that I *don't* have this problem when running on x86_64 precise.
>>>
>>> The issue can be recreated with:
>>>
>>> $ compiz composite opengl
>>>
>>> I added some debugging messages to pluginclasshandler.h to get a better
>>> feeling of what is going on, and ran on both my desktop and on ARM.
>>> This is the output near the point when GLScreen get initialized:
>>>
>>> ...
>>>
>>> compiz (core) - Info: get(): mIndex.initiated for "8GLScreen_index_4" : 0
>>> compiz (core) - Info: initializeIndex(): Initializining index value "8GLScreen_index_4"
>>> compiz (core) - Info: initializeIndex(): Private index value added for "8GLScreen_index_4"
>>> compiz (core) - Info: getInstance(): Get instance for "8GLScreen_index_4"
>>> compiz (core) - Info: getInstance(): Spawning new class for "8GLScreen_index_4"
>>> compiz (core) - Info: ctor(): mIndex.initiated for "8GLScreen_index_4" : 1
>>> compiz (core) - Info: ctor(): Increasing reference count for "8GLScreen_index_4": 1
>>>
>>> --- x86_64 ---
>>> compiz (core) - Info: get(): mIndex.initiated for "15CompositeScreen_index_4" : 1
>>> --- armhf ---
>>> compiz (core) - Info: get(): mIndex.initiated for "15CompositeScreen_index_4" : 0
>>> compiz (core) - Info: initializeIndex(): Initializining index value "15CompositeScreen_index_4"
>>> compiz (core) - Fatal: initializeIndex(): Private index value "15CompositeScreen_index_4" already stored in screen.
>>
>> After the composite plugin loads and mIndex.initiated is set to 1,
>> place a watchpoint on mIndex.initiated (it should be a separate
>> template instantiation for each different class) and check if it
>> changes, or check if we are reading mIndex.initiated from a different
>> address, and if so, check the addresses of this for each constructor
>> and destructor being called. (could be a compiler bug, I've hit these
>> on this part of the code before).
>>
>>> -------------
>>>
>>> In the armhf case, CompositeScreen is erroneously considered not
>>> initialized, and is initialiazed again, therefore messing up the plugin system.
>>>
>>> I am trying to figure out if this is a manifestation of some kind of memory
>>> corruption that doesn't affect us on x86_64 for whatever reason (alignment,
>>> integer size etc), or something completely different.
>>>
>>> Thoughts?
>>>
>>> Thanks,
>>> Alexandros
>>
>>
>>
>> --
>> Sam Spilsbury
>>
>
> Hi all,
>
> (I have also added Michael, Andrew and Ulrich from the Linaro toolchain group
> to the recipients. Hi!)
>
> Checking the addresses, as Sam suggested, I found that there are two different
> PluginClassHandler<CompositeScreen, CompScreen, 4>::mIndex and
> PluginClassHandler<CompositeWindow, CompWindow, 4>::mIndex objects.
>
> After a bit of investigation, objdump gave an explanation:
>
> objdump -t /usr/lib/compiz/libcomposite.so | c++filt | grep mIndex
>
> -- x86_64 --
> 0000000000277a80 u O .bss 0000000000000010 PluginClassHandler<CompositeWindow, CompWindow, 4>::mIndex
> 0000000000277a70 u O .bss 0000000000000010 PluginClassHandler<CompositeScreen, CompScreen, 4>::mIndex
> -- armhf --
> 00065648 w O .bss 00000010 PluginClassHandler<CompositeWindow, CompWindow, 4>::mIndex
> 00065658 w O .bss 00000010 PluginClassHandler<CompositeScreen, CompScreen, 4>::mIndex
> ------------
>
> And the same kind of output for libopengl.so
>
> On x86_64 the symbols are marked 'u': 'unique global', whereas on armhf
> they are marked 'w': 'weak'. This seems to be causing our troubles.
>
> I have produced a small test case for this:
>
> http://people.linaro.org/~afrantzis/cpp_unique_global.tar.gz
>
> Building and running 'LD_LIBRARY_PATH=. ./main' on x86_64 prints out f1 and f2
> with the same address, whereas on armhf the addresses are different (i.e. two
> different objects). On x86_64 the symbol A<int>::a is 'u', on armhf it is 'w'.
>
> For completeness, when running without templates (edit a.h to change) the two
> printed addresses are different on both x86_64 and armhf. Also A::a is 'g':
> 'normal global' for both.
>
> Michael, Andrew, Ulrich can you please give us some insight into the situation?
> Does this seem like a compiler or linker bug on ARM, or is the code depending
> on undefined behavior, or something different? I have pasted the used g++
> versions at the end of the email.
>
> Thanks,
> Alexandros
>
> --- g++ x86_64 --
> Using built-in specs.
> COLLECT_GCC=g++
> COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.6/lto-wrapper
> Target: x86_64-linux-gnu
> Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 4.6.3-1ubuntu2' --with-bugurl=file:///usr/share/doc/gcc-4.6/README.Bugs --enable-languages=c,c++,fortran,objc,obj-c++,go --prefix=/usr --program-suffix=-4.6 --enable-shared --enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.6 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-plugin --enable-objc-gc --disable-werror --with-arch-32=i686 --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
> Thread model: posix
> gcc version 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu2)
>
> --- g++ armhf --
> Using built-in specs.
> COLLECT_GCC=g++
> COLLECT_LTO_WRAPPER=/usr/lib/gcc/arm-linux-gnueabihf/4.6/lto-wrapper
> Target: arm-linux-gnueabihf
> Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 4.6.3-1ubuntu2' --with-bugurl=file:///usr/share/doc/gcc-4.6/README.Bugs --enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.6 --enable-shared --enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.6 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-plugin --enable-objc-gc --enable-multilib --disable-sjlj-exceptions --with-arch=armv7-a --with-float=hard --with-fpu=vfpv3-d16 --with-mode=thumb --disable-werror --enable-checking=release --build=arm-linux-gnueabihf --host=arm-linux-gnueabihf --target=arm-linux-gnueabihf
> Thread model: posix
> gcc version 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu2)
>
Hi!
* Bug reports
Made an effort clean up among the remaining not-triaged bug. Michael will
help out with 941676, where the failure is on power-pc.
* Wiki
Created a wiki page for running benchmarks in cbuild:
https://wiki.linaro.org/WorkingGroups/ToolChain/Benchmarks/RunningBenchmark…
* V8
Build system has changed in V8 from SCones to GYP. With GYP I can pass the
normal flags like CXXFLAGS to control the build, so this looks like a good
change.
I have created a cbuild make file, patterned after the other benchmark make
files.
Working on x86 sofar, will go for arm next week. Will also add a parser for
the results.
Regards
Åsa
== GCC ==
* Checked patch to generate usat/ssat instructions into
Linaro GCC 4.6 and 4.7.
* Submitted (first part of) fwprop-subreg patch for mainline.
* Submitted Ira's vectorizer patches for mainline.
* Ongoing work on improving end-of-loop value computation.
* Patch review week.
== Misc ==
* On leave 3/9 - 3/14.
Mit freundlichen Gruessen / Best Regards
Ulrich Weigand
--
Dr. Ulrich Weigand | Phone: +49-7031/16-3727
STSM, GNU compiler and toolchain for Linux on System z and Cell/B.E.
IBM Deutschland Research & Development GmbH
Vorsitzender des Aufsichtsrats: Martin Jetter | Geschäftsführung: Dirk
Wittkopp
Sitz der Gesellschaft: Böblingen | Registergericht: Amtsgericht
Stuttgart, HRB 243294
Hi
Updated sysroots for binary toolchain are available at [1]. This time I
split -dev and -dbg sysroots so as long as dbgsym are not needed less
disk space is used.
Please take a look at them and report any issues.
1. http://people.linaro.org/~hrw/generic-linux/sysroots/20120301/
Hello,
My name is Jiandong Zheng and am working on a few ARM specific projects.
I have been using Linaro toolchain coming with Ubuntu to do Cortext-A9
building. I also need to maintain code for old ARM11 SoC so that Linaro
toolchain is my preference and it did the job well back in Maverick days
if I remember correctly.
However, in Precise, I have troubles running this ARM11 u-boot and
kernel built with Linaro toolchain, eventually I found that my old gcc
4.3.2 toolchain can still build workable u-boot and kernel so that
Linaro toolchain (gcc 4.6.2) seems the problem. I understand that
Linaro's focus has been ARMv7 or above but I am wondering if its
toolchain can still be used for older ARM architectures.
Thanks,
JD
Hi Michael,
A new bug triaging question.
https://bugs.launchpad.net/ubuntu/+source/ppl/+bug/941676
This one is special too because the failure is on powerpc.
This means, I cannot reproduce it easily, and scan through the toolchains
(without building).
Matthias has given some information and a guess of what is failing. My idea
was to just summarize this, and let the person who takes on the bug make
the powerpc investigation.
How do we handle bugs on other architectures in general?
Best regards
Åsa
Hi!
I need a little help with triaging of this bug, it is a little different
from the ones I have triaged so far:
https://bugs.launchpad.net/launchpad/+bug/945503 - gcc-4.7 branch imports
fail (timeouts)
It is already set to Confirmed, my question is what is needed to go to the
triaged stage?
Also, the comments from wgrant and jelmer somewhat indicates that there is
no problem.
Best regards
Åsa
Hello,
since this long-standing problem just hit me again, I had a quick look at
test failures in our farm that appear to occur whenever the directory name
contains a string that is being checked for via a "scan-assembler" test,
e.g.:
+FAIL: gcc.target/arm/sat-1.c scan-assembler-times ssat 4
+FAIL: gcc.target/arm/sat-1.c scan-assembler-times usat 4
I had been assuming this happens because the directory name somehow finds
its name into the assembler file, e.g. via a .file directive or DWARF data,
and therefore an additional instance of the search string is being detected
erroneously.
However, when I attemted to re-create the scenario by building myself
within a directory that has the same name, but on my local machine, the
tests when through fine. And indeed, inspecting the assembler source shows
that that there is no debug info at all; while there is a .file directive,
it contains just the file base name without any directory name; and in fact
the directory name does not show up at all within the assembler file.
Something must still be different in the runs that take place on the build
farm; but I currently do not understand what that might be.
Michael, is there a way to interact with the build process on the build
farm machines themselves to try and find out what's going on here?
Mit freundlichen Gruessen / Best Regards
Ulrich Weigand
--
Dr. Ulrich Weigand | Phone: +49-7031/16-3727
STSM, GNU compiler and toolchain for Linux on System z and Cell/B.E.
IBM Deutschland Research & Development GmbH
Vorsitzende des Aufsichtsrats: Martina Koederitz | Geschäftsführung: Dirk
Wittkopp
Sitz der Gesellschaft: Böblingen | Registergericht: Amtsgericht
Stuttgart, HRB 243294
Hi toolchain folks,
I have a problem with U-boot compiled for an ARMv4 system (Integrator)
using Linaro 2012.02-20120222, it just crashes. Compiling the same
U-Boot with CodeSourcery 2010-q1 works fine.
Symptom:
Resetting CPU ...
undefined instruction
pc : [<07fdecd4>] lr : [<07fdeb34>]
sp : 07f91380 ip : 00000000 fp : 00000001
r10: 010258fc r9 : 00000000 r8 : 07f94f64
r7 : 07f94eb0 r6 : 00989680 r5 : 000186a0 r4 : 000186a0
r3 : 000003e8 r2 : 000f423f r1 : 000f4240 r0 : 05f5e100
Flags: nzCv IRQs on FIQs on Mode SVC_32
(repeated ad nauseam)
The only hint I have is the constant 000186a0, which appears
here in the put_dec() routine from U-boots vsprintf(), which is
nothing special, it's Douglas Jones' binary to decimal conversion
code from the Linux kernel, but the compiles objects DOES
contain calls to __aeabi_uidivmod, __udivsi3, __div64_32.
Do we know of any potential trouble in these helpers on ARMv4?
The file containing these functions is compiled like this:
arm-linux-gnueabi-gcc -M -g -Os -fno-common -ffixed-r8 -msoft-float
-D__KERNEL__ -DCONFIG_SYS_TEXT_BASE=0x01000000
-I/var/linus/u-boot/build-integrator/include2
-I/var/linus/u-boot/build-integrator/include
-I/var/linus/u-boot/include -fno-builtin -ffreestanding -nostdinc
-isystem /home/linus/src/gcc-linaro-arm-linux-gnueabi-2012.02-20120222_linux/bin/../lib/gcc/arm-linux-gnueabi/4.6.3/include
-pipe -DCONFIG_ARM -D__ARM__ -marm -mabi=aapcs-linux
-mno-thumb-interwork -march=armv4 -MQ
/var/linus/u-boot/build-integrator/lib/vsprintf.o vsprintf.c
>/var/linus/u-boot/build-integrator/lib/.depend.vsprintf
Yours,
Linus Walleij
