Bug#980204: gdc: Resulting executables segfault on mipsel architecture (signal 11)
On Fri, Jan 22, 2021 at 12:59:34PM +0100, Iain Buclaw wrote:
> > (mipsel-chroot)$ printf 'import std.stdio;\nvoid main() { writeln("Hello, World!"); }\n' > hello.d ; gdc hello.d && ./a.out
> > qemu: uncaught target signal 11 (Segmentation fault) - core dumped
> > Segmentation fault
> >
> > This is with host running Buster with qemu-user 1:5.2+dfsg-3~bpo10+1
> > but the other not-too-complicated D programs fail on Debian buildd infrastructure too:
> > https://buildd.debian.org/status/fetch.php?pkg=ironseed&arch=mipsel&ver=0.3.6-4&stamp=1610676343&raw=0
>
> Building current gdc-master on a MIPS server (running Debian Jessie, I
> don't seem to have access to the Buster node), I can't reproduce the
> segfault. What are the chances of it being QEMU that's the cause?
I would be first to blame qemu in my virtual chroot on amd64, but I
was under impression the Debian buildd machine that failed was real
hardware? I could be wrong though, this is information for buildd machine
referenced in bug report where gdc failed:
https://db.debian.org/machines.cgi?host=eberlin
The program there segfaulted there was more complex than simple "hello world", though.
(but it does work without any problems on all other architectures with gdc)
> Also, are you linking to the static or shared libphobos library?
shared (default):
(mipsel-chroot):/tmp/w$ dpkg -l gdc | grep gdc
ii gdc 4:10.2.1-1 mipsel D compiler (language version 2), based on the GCC backend
(mipsel-chroot):/tmp/w$ printf 'import std.stdio;\nvoid main() { writeln("Hello, World!"); }\n' > hello.d ; gdc hello.d && ./a.out
qemu: uncaught target signal 11 (Segmentation fault) - core dumped
Segmentation fault
(mipsel-chroot):/tmp/w$ file a.out
a.out: ELF 32-bit LSB pie executable, MIPS, MIPS32 rel2 version 1 (SYSV), dynamically linked, interpreter /lib/ld.so.1, BuildID[sha1]=36c5576b94519b416c1996018760159ae925bc34, for GNU/Linux 3.2.0, not stripped
(mipsel-chroot):/tmp/w$ ldd a.out
libgphobos.so.1 => /lib/mipsel-linux-gnu/libgphobos.so.1 (0x7f1a3000)
libgcc_s.so.1 => /lib/mipsel-linux-gnu/libgcc_s.so.1 (0x7f16b000)
libc.so.6 => /lib/mipsel-linux-gnu/libc.so.6 (0x7efd1000)
libm.so.6 => /lib/mipsel-linux-gnu/libm.so.6 (0x7ef52000)
libpthread.so.0 => /lib/mipsel-linux-gnu/libpthread.so.0 (0x7ef21000)
libdl.so.2 => /lib/mipsel-linux-gnu/libdl.so.2 (0x7ef0d000)
libz.so.1 => /lib/mipsel-linux-gnu/libz.so.1 (0x7eee2000)
/lib/ld.so.1 (0x7ffc9000)
But good point, when I try to link this "hello world" example statically, it
throws warnings, but works!
(mipsel-chroot):/tmp/w$ printf 'import std.stdio;\nvoid main() { writeln("Hello, World!"); }\n' > hello.d ; gdc -static hello.d && ./a.out
/usr/bin/ld: /usr/lib/gcc/mipsel-linux-gnu/10/libgphobos.a(elf_shared.o): in function `_D3gcc8sections10elf_shared18pinLoadedLibrariesFNbNiZPv':
/build/gcc-10-XdUysA/gcc-10-10.2.1/build/mipsel-linux-gnu/libphobos/libdruntime/../../../../src/libphobos/libdruntime/gcc/sections/elf_shared.d:250: warning: Using 'dlopen' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
/usr/bin/ld: /usr/lib/gcc/mipsel-linux-gnu/10/libgphobos.a(stdio.o): in function `_D3std5stdio11openNetworkFAyatZS3std5stdio4File':
/build/gcc-10-XdUysA/gcc-10-10.2.1/build/mipsel-linux-gnu/libphobos/src/../../../../src/libphobos/src/std/stdio.d:5137: warning: Using 'gethostbyname' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
Hello, World!
(mipsel-chroot):/tmp/w$ file a.out
a.out: ELF 32-bit LSB executable, MIPS, MIPS32 rel2 version 1 (GNU/Linux), statically linked, BuildID[sha1]=2da3a20d4fe083f1c33f79e4d259f91f8ed7696d, for GNU/Linux 3.2.0, with debug_info, not stripped
(mipsel-chroot):/tmp/w$ dpkg -l "libgphobos*" | grep '^ii'
ii libgphobos-10-dev:mipsel 10.2.1-6 mipsel Phobos D standard library
ii libgphobos-dev:mipsel 10.2.1-1 mipsel Phobos D standard library
ii libgphobos1:mipsel 10.2.1-6 mipsel Phobos D standard library (runtime library)
> Running the testsuite now, to see if there's any reported failures, but
> none so far...
However, when I try to build and run the more complex program Data_Generators/makedata/logmake.d
from this version: http://snapshot.debian.org/archive/debian/20210115T023714Z/pool/main/i/ironseed/ironseed_0.3.6-4.dsc
it still fails with segfault on my qemu mipsel chroot, even when '-static' is added
(as it did on Debian buildd machine "eberlin.debian.org"):
(mipsel-chroot):/tmp/w/is/ironseed-0.3.6$ gdc -static -o Data_Generators/makedata/logmake Data_Generators/makedata/logmake.d Data_Generators/makedata/data.d && Data_Generators/makedata/logmake Data_Generators/makedata/logs.txt data/titles.dta data/log.dta
/usr/bin/ld: /usr/lib/gcc/mipsel-linux-gnu/10/libgphobos.a(elf_shared.o): in function `_D3gcc8sections10elf_shared18pinLoadedLibrariesFNbNiZPv':
/build/gcc-10-XdUysA/gcc-10-10.2.1/build/mipsel-linux-gnu/libphobos/libdruntime/../../../../src/libphobos/libdruntime/gcc/sections/elf_shared.d:250: warning: Using 'dlopen' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
/usr/bin/ld: /usr/lib/gcc/mipsel-linux-gnu/10/libgphobos.a(stdio.o): in function `_D3std5stdio11openNetworkFAyatZS3std5stdio4File':
/build/gcc-10-XdUysA/gcc-10-10.2.1/build/mipsel-linux-gnu/libphobos/src/../../../../src/libphobos/src/std/stdio.d:5137: warning: Using 'gethostbyname' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
qemu: uncaught target signal 11 (Segmentation fault) - core dumped
Segmentation fault
(mipsel-chroot):/tmp/w/is/ironseed-0.3.6$ file Data_Generators/makedata/logmake
Data_Generators/makedata/logmake: ELF 32-bit LSB executable, MIPS, MIPS32 rel2 version 1 (GNU/Linux), statically linked, BuildID[sha1]=73dc65478408cfd9c17fba098575b7fe4078dbc7, for GNU/Linux 3.2.0, with debug_info, not stripped
If unable to reproduce elsewhere, perhaps you could try to get
"dget -x http://snapshot.debian.org/archive/debian/20210115T023714Z/pool/main/i/ironseed/ironseed_0.3.6-4.dsc";
and build on your real MIPS hardware and see it if builds?
(note that ironseed version 0.3.6-4 is required, as 0.3.6-5 and newer versions
contain a workaround, so they do not try to use gdc on mipsel architecture
as it is is not working)
--
Opinions above are GNU-copylefted.
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