mpv: introspector killed, possibly OOM

[kasper93]

Hi,

This is mostly a question if there is something we could to to workaround this, I tried making targets smaller and exclude some files from introspect or, but it fails.

See: https://oss-fuzz-build-logs.storage.googleapis.com/log-49c8a121-941c-4911-be95-5f06c0c7bc8a.txt

Step #6 - "compile-libfuzzer-introspector-x86_64": /usr/local/bin/compile: line 333:  8993 Killed                  python3 /fuzz-introspector/src/main.py report $REPORT_ARGS

It works locally, so it is likely OOM on build machine. I wonder if the introspector itself could be optimized to be less resource heavy?

Not highly important, but I figured to report it in case there are some low hanging fruits to grab :)

Thanks,
Kacper

[kleisauke]

I suspect that libvips might be experiencing a similar issue, see:
https://introspector.oss-fuzz.com/project-profile?project=libvips
https://oss-fuzz-build-logs.storage.googleapis.com/log-c652af70-8e81-4bfc-93c1-8cbf2665529e.txt

This problem seems to occur after commit libvips/libvips@65a1371, which added a couple more fuzzers. I was unable to reproduce this issue locally using:

$ python infra/helper.py build_image libvips
$ python infra/helper.py build_fuzzers --sanitizer introspector --engine libfuzzer --architecture x86_64 libvips

[kasper93]

@kleisauke: your issue is during linking. With lto and especially with full lto there is a lot of memory needed. Reduce concurrent linking jobs to fix this. I see libvips uses meson, so backend_max_links will do the job. I don't know what is the RAM quota on builder machines, so you will have to experiment with number of jobs that doesn't fail... For mpv I use -Dbackend_max_links=4 else, ninja would start linking all fuzzer binaries at the same time.

[kleisauke]

@kasper93 Thanks for the hat tip, I'll try to build with -Dbackend_max_links=4 to see if this fixes it.

FWIW, it seems that libvips' compile tests are also failing. However, since none of these tests are mandatory, the issue went unnoticed. I should probably use a similar workaround to the one described in #7583 (comment).

[kasper93]

FWIW, it seems that libvips' compile tests are also failing. However, since none of these tests are mandatory, the issue went unnoticed. I should probably use a similar workaround to the one described in #7583 (comment).

Ah, indeed the linker issue with meson. I did this #12081 for mpv.

EDIT: For reference here is the issue about it #12167