pdns-recursos fails on mips64

[neheb]

https://downloads.openwrt.org/snapshots/faillogs/mips64_octeonplus/packages/pdns-recursor/compile.txt

@James-TR

looks like some boost detection bug.

[James-TR]

Thanks I'll take a look into this one and get input from the developers :)

[James-TR]

pdns-recursor 4.2.0 has been released. This may still have the same issue. We can see if it's still there or try to fix prior to bumping.

[James-TR]

PowerDNS/pdns#7951 introduced changes to boost.m4 which fixed the detection of boost, however now it simply fails during configure instead of falsely showing boost_context as available. Does octeonplus support System V ucontexts?

Edit: The changes aren't yet in a release, and may be included in 4.2.1

[neheb]

It should.

[neheb]

I looked at this again. I can't figure it out. I'm guessing it's a boost problem.

Note that the compiler for this platform has a + in its name. This has caused issues with other packages as well. This is an example: https://github.com/openwrt/packages/blob/master/multimedia/gst1-libav/Makefile#L145

ping @ClaymorePT

[ClaymorePT]

Ok, I have been analysing this issue. For what I can tell, this is an issue regarding the mips64 arch and the lack of support of f_context for it (f_context arch support)

As an alternative, for mips64 I could try to use u_context. It will be slower but it's an alternative.

[neheb]

Weird that mips is supported but not mips64.

[ClaymorePT]

I also thought that, but its what the documentation sugests :/

[ClaymorePT]

Ok, the fix that I suggested is a no-go.

After trying that approach, I get this when compiling pdns-recursor

libboost_context.so: undefined reference to 'getcontext' 
mtasker_fcontext.cc:157: undefined reference to `jump_fcontext'

which happens because 'getcontext' was deprecated since POSIX.1-2003 (as predicted by Boost.Context documentation). musl does not support this and as so, it is not possible to link pdns-recursor.

@neheb The best thing I can do is to disable boost.context for mips64 :/
What are your thoughts about this?

[neheb]

From reading the documentation again, it seems that nobody has written ASM for MIPS64. Probably because of a lack of devices.

undefined reference to 'getcontext' is weird. POSIX may deprecate it but musl does not. Then again, there is only a definition of getcontext in include/ucontext.h with no corresponding function. I guess that's what undefined reference means...

Looking at uClibc-ng, getcontext is available on all platforms supported by OpenWrt except mips64 and ARC. The latter fails compilation for a different reason: https://downloads.openwrt.org/snapshots/faillogs/arc_arc700/packages/pdns-recursor/compile.txt

glibc story is the same.

Disabling boost.context for mips64 and ARC seems correct here.

[neheb]

Yeah

/home/mangix/devstuff/openwrt/build_dir/target-arc_arc700_uClibc/pdns-recursor-4.2.0/mtasker_fcontext.cc:199: undefined reference to `jump_fcontext'
/home/mangix/devstuff/openwrt/staging_dir/toolchain-arc_arc700_gcc-9.2.0_uClibc/lib/gcc/arc-openwrt-linux-uclibc/9.2.0/../../../../arc-openwrt-linux-uclibc/bin/ld: /home/mangix/devstuff/openwrt/build_dir/target-arc_arc700_uClibc/pdns-recursor-4.2.0/mtasker_fcontext.cc:199: undefined reference to `jump_fcontext'
/home/mangix/devstuff/openwrt/staging_dir/toolchain-arc_arc700_gcc-9.2.0_uClibc/lib/gcc/arc-openwrt-linux-uclibc/9.2.0/../../../../arc-openwrt-linux-uclibc/bin/ld: mtasker_context.o: in function `pdns_makecontext(pdns_ucontext_t&, boost::function<void ()>&)':
/home/mangix/devstuff/openwrt/build_dir/target-arc_arc700_uClibc/pdns-recursor-4.2.0/mtasker_fcontext.cc:219: undefined reference to `make_fcontext'
/home/mangix/devstuff/openwrt/staging_dir/toolchain-arc_arc700_gcc-9.2.0_uClibc/lib/gcc/arc-openwrt-linux-uclibc/9.2.0/../../../../arc-openwrt-linux-uclibc/bin/ld: /home/mangix/devstuff/openwrt/build_dir/target-arc_arc700_uClibc/pdns-recursor-4.2.0/mtasker_fcontext.cc:219: undefined reference to `make_fcontext'
/home/mangix/devstuff/openwrt/staging_dir/toolchain-arc_arc700_gcc-9.2.0_uClibc/lib/gcc/arc-openwrt-linux-uclibc/9.2.0/../../../../arc-openwrt-linux-uclibc/bin/ld: /home/mangix/devstuff/openwrt/build_dir/target-arc_arc700_uClibc/pdns-recursor-4.2.0/mtasker_fcontext.cc:232: undefined reference to `jump_fcontext'
/home/mangix/devstuff/openwrt/staging_dir/toolchain-arc_arc700_gcc-9.2.0_uClibc/lib/gcc/arc-openwrt-linux-uclibc/9.2.0/../../../../arc-openwrt-linux-uclibc/bin/ld: /home/mangix/devstuff/openwrt/build_dir/target-arc_arc700_uClibc/pdns-recursor-4.2.0/mtasker_fcontext.cc:232: undefined reference to `jump_fcontext'
/home/mangix/devstuff/openwrt/staging_dir/toolchain-arc_arc700_gcc-9.2.0_uClibc/lib/gcc/arc-openwrt-linux-uclibc/9.2.0/../../../../arc-openwrt-linux-uclibc/bin/ld: mtasker_context.o: in function `threadWrapper':
/home/mangix/devstuff/openwrt/build_dir/target-arc_arc700_uClibc/pdns-recursor-4.2.0/mtasker_fcontext.cc:129: undefined reference to `jump_fcontext'
/home/mangix/devstuff/openwrt/staging_dir/toolchain-arc_arc700_gcc-9.2.0_uClibc/lib/gcc/arc-openwrt-linux-uclibc/9.2.0/../../../../arc-openwrt-linux-uclibc/bin/ld: /home/mangix/devstuff/openwrt/build_dir/target-arc_arc700_uClibc/pdns-recursor-4.2.0/mtasker_fcontext.cc:129: undefined reference to `jump_fcontext'
/home/mangix/devstuff/openwrt/staging_dir/toolchain-arc_arc700_gcc-9.2.0_uClibc/lib/gcc/arc-openwrt-linux-uclibc/9.2.0/../../../../arc-openwrt-linux-uclibc/bin/ld: /home/mangix/devstuff/openwrt/build_dir/target-arc_arc700_uClibc/pdns-recursor-4.2.0/mtasker_fcontext.cc:157: undefined reference to `jump_fcontext'
/home/mangix/devstuff/openwrt/staging_dir/toolchain-arc_arc700_gcc-9.2.0_uClibc/lib/gcc/arc-openwrt-linux-uclibc/9.2.0/../../../../arc-openwrt-linux-uclibc/bin/ld: mtasker_context.o:/home/mangix/devstuff/openwrt/build_dir/target-arc_arc700_uClibc/pdns-recursor-4.2.0/mtasker_fcontext.cc:157: more undefined references to `jump_fcontext' follow
collect2: error: ld returned 1 exit status
Makefile:1261: recipe for target 'pdns_recursor' failed
make[5]: *** [pdns_recursor] Error 1
make[5]: Leaving directory '/home/mangix/devstuff/openwrt/build_dir/target-arc_arc700_uClibc/pdns-recursor-4.2.0'
Makefile:1495: recipe for target 'all-recursive' failed
make[4]: *** [all-recursive] Error 1
make[4]: Leaving directory '/home/mangix/devstuff/openwrt/build_dir/target-arc_arc700_uClibc/pdns-recursor-4.2.0'
Makefile:1099: recipe for target 'all' failed
make[3]: *** [all] Error 2
make[3]: Leaving directory '/home/mangix/devstuff/openwrt/build_dir/target-arc_arc700_uClibc/pdns-recursor-4.2.0'
Makefile:62: recipe for target '/home/mangix/devstuff/openwrt/build_dir/target-arc_arc700_uClibc/pdns-recursor-4.2.0/.built' failed
make[2]: *** [/home/mangix/devstuff/openwrt/build_dir/target-arc_arc700_uClibc/pdns-recursor-4.2.0/.built] Error 2
make[2]: Leaving directory '/home/mangix/devstuff/openwrt/feeds/packages/net/pdns-recursor'
time: package/feeds/packages/pdns-recursor/compile#258.41#15.76#266.28
package/Makefile:111: recipe for target 'package/feeds/packages/pdns-recursor/compile' failed
make[1]: *** [package/feeds/packages/pdns-recursor/compile] Error 2
make[1]: Leaving directory '/home/mangix/devstuff/openwrt'
/home/mangix/devstuff/openwrt/include/toplevel.mk:216: recipe for target 'package/pdns-recursor/compile' failed

[ClaymorePT]

From reading the documentation again, it seems that nobody has written ASM for MIPS64. Probably because of a lack of devices.

Yep, I noticed that when I looked at the src/asm folder and noticed the same.
Nothing to do here :/

Disabling boost.context for mips64 and ARC seems correct here.

Doing so.

[ClaymorePT]

Ok. I've opened a PR @ #9838 which will disable Boost.Context for arc and mips64.

[neheb]

@ClaymorePT I see boostorg/context#92 has a bunch of mips64 code for context. Any idea about that?

[ClaymorePT]

@neheb Are you talking about this?

[ClaymorePT]

@neheb Ah! I see that you I've found the PR. I'm not monitoring such changes. They seem to be recent ones.