12.11.0 on PPCLE requires libatomic.so.1

[Flarna]

• Version: 12.11.0
• Platform: PPCLE, Linux 3149024480ec 5.0.0-25-generic GitHub issue management #26~18.04.1-Ubuntu SMP Thu Aug 1 13:50:51 UTC 2019 ppc64le ppc64le ppc64le GNU/Linux
• Subsystem: build, deps

node.js 12.11.0 is not starting up on my PPCLE machine where 12.10.0 was running fine.

Error seen: node: error while loading shared libraries: libatomic.so.1: cannot open shared object file: No such file or directory

It seems that 12.11.0 has new dependencies to libatomic.so.1 and librt.so.1:

$ ldd ./v12.11.0/bin/node
linux-vdso64.so.1 =>  (0x00007535a5f60000)
libatomic.so.1 => not found
libdl.so.2 => /lib/powerpc64le-linux-gnu/libdl.so.2 (0x00007535a5f20000)
librt.so.1 => /lib/powerpc64le-linux-gnu/librt.so.1 (0x00007535a5ef0000)
libstdc++.so.6 => /usr/lib/powerpc64le-linux-gnu/libstdc++.so.6 (0x00007535a5ce0000)
libm.so.6 => /lib/powerpc64le-linux-gnu/libm.so.6 (0x00007535a5bf0000)
libgcc_s.so.1 => /lib/powerpc64le-linux-gnu/libgcc_s.so.1 (0x00007535a5bc0000)
libpthread.so.0 => /lib/powerpc64le-linux-gnu/libpthread.so.0 (0x00007535a5b80000)
libc.so.6 => /lib/powerpc64le-linux-gnu/libc.so.6 (0x00007535a59b0000)
/lib64/ld64.so.2 (0x00007535a5f80000)
	
$ ldd ./v12.10.0/bin/node
linux-vdso64.so.1 =>  (0x000073b7b24d0000)
libdl.so.2 => /lib/powerpc64le-linux-gnu/libdl.so.2 (0x000073b7b2490000)
libstdc++.so.6 => /usr/lib/powerpc64le-linux-gnu/libstdc++.so.6 (0x000073b7b2280000)
libm.so.6 => /lib/powerpc64le-linux-gnu/libm.so.6 (0x000073b7b2190000)
libgcc_s.so.1 => /lib/powerpc64le-linux-gnu/libgcc_s.so.1 (0x000073b7b2160000)
libpthread.so.0 => /lib/powerpc64le-linux-gnu/libpthread.so.0 (0x000073b7b2120000)
libc.so.6 => /lib/powerpc64le-linux-gnu/libc.so.6 (0x000073b7b1f50000)
/lib64/ld64.so.2 (0x000073b7b24f0000)

Is this an intended change?

[richardlau]

I think 12.11.0 is the first PPCLE 12.x release we've done on Centos 7 (nodejs/build#1885) instead of the End-of-Life Ubuntu 14.04.

cc @nodejs/platform-ppc @sam-github

[Flarna]

I can confirm that a simple apt-get install libatomic1 results in a working 12.11.0 on my PPCLE machine.

[Flarna]

Just found that my description regarding the used platform is incomplete.
I run node in a docker container using ubuntu:16.04 as base image; 18.04.1 is the version of the docker host.

[mhdawson]

FYI @sam-github

[sam-github]

It was my observation and intention that devtoolset builds on centos7 would statically link in more of the lib dependencies, avoiding this problem. I'm looking into why that didn't happen, but rebuilds are bit slow because of nodejs/build#1927

[mhdawson]

I don't think the toolset handles libraries other that libc++

[sam-github]

So far I have confirmed that linking on ubuntu14.04 with g++-6 uses ...tools/v8_gypfiles/libv8_initializers.a -latomic -ldl -lrt -lm ..., and the identical linker command line is
used on centos7 with devtoolset-6.

On ubuntu/gcc-6 the linked executable has no dependency on libatomic, and on centos/devtoolset-6 it does.

So the open question might be not why centos7 does depend on the specified libs, but why ubuntu doesn't.

I'll keep poking at this.

[sam-github]

@Flarna I removed the part of your description where it listed the dependency on libdl.so.2 as new, in your output you can it is present in both, it must have been a typo.

What I've found so far is:

1. Neither of -latomic -lrt are required to link node on ubuntu/gcc or centos7/devtoolset
2. ubuntu gcc seems to ignore unused link libs, devtoolset seems to generate executables with a reference to them.

As to why that is, or what can be done about it, still looking.

On our side, the obvious fix would be to not specify unnecessary libraries on the node link lines. I tried removing ppc64le from the platforms that need -latomic and got a working binary on ubuntu and centos7. I'd have to add a conditional to do the same for -lrt (it looks to be the POSIX.4 realtime APIs).

@targos any comment on that? The link libs seem to have been added with V8 7.5, #28005 from #27375, but since v8 doesn't build on ppc64le (to my knowlege), they might just have added them to be safe, on the assumption they'd be unused if they weren't needed.

[sam-github]

@nodejs/v8 see above, any comment on what I asked targos?

[targos]

This is the relevant config in V8's BUILD.gn: https://github.com/v8/v8/blob/318d66d95f94487cdac2322795a63ea613ef943b/BUILD.gn#L3381-L3388

We own v8.gyp so we could deviate from upstream here, if libatomic is really never needed (it might depend on certain build options).