Hi, On Sun, Feb 14, 2021 at 02:12:17PM +0000, Vincent Arkesteijn wrote: > Firefox is killed with SIGILL shortly after startup: > $ firefox-esr -safe-mode > Illegal instruction > $
This is due to the fact that some armhf CPUs do not have support for NEON instructions. skia used to detect such support at runtime, but that behavior was removed in https://github.com/google/skia/commit/809ccf37ec836d0df64afd0b13023fd968d505a4 Firefox seems to erroneously enable NEON in places where it shouldn't. Trying to figure out exactly where and what's the best way to address this. Meanwhile, to reproduce and debug this issue on a amd64 machine: apt install debootstrap qemu-user-static binfmt-support schroot Trying to run a armhf binary on the x86 host will invoke qemu-arm-static, see: /usr/sbin/update-binfmts --display qemu-arm ls -l /usr/libexec/qemu-binfmt/arm-binfmt-P Create a armhf chroot: debootstrap --arch=armhf sid /srv/sid-armhf printf '[armhf]\ntype=directory\ndirectory=/srv/sid-armhf\n' >> /etc/schroot/schroot.conf Install and run firefox-esr in the chroot: schroot -c armhf (armhf)root@ariel:/home/ema# apt install --no-install-recommends firefox-esr Firefox seems to be working: (armhf)root@ariel:/home/ema# firefox --help | head -1 Usage: firefox-esr [ options ... ] [URL] The reason why firefox does not crash here is that the default armhf CPU emulated by qemu-arm-static has NEON support. We can override that by setting QEMU_CPU to cortex-r5f (which cannot execute NEON instructions) and reproduce the issue: (armhf)root@ariel:/home/ema# QEMU_CPU=cortex-r5f firefox qemu: uncaught target signal 4 (Illegal instruction) - core dumped Illegal instruction To get a backtrace, install Firefox's debugging symbols in the chroot: (armhf)root@ariel:/home/ema# echo 'deb http://deb.debian.org/debian-debug sid-debug main' > /etc/apt/sources.list.d/debug.list (armhf)root@ariel:/home/ema# apt update && apt install firefox-esr-dbgsym And do the following on the x86 host: dpkg --add-architecture armhf apt install libc6:armhf libc6-dbg:armhf gdb-multiarch LD_LIBRARY_PATH=/srv/sid-armhf/usr/lib/arm-linux-gnueabihf qemu-arm-static -g 1234 -cpu cortex-r5f /srv/sid-armhf/usr/bin/firefox-esr --private-window In another terminal, again on the host, this should give you a backtrace: gdb-multiarch -q /srv/sid-armhf/usr/bin/firefox-esr -ex 'set architecture arm' -ex 'target remote :1234' -ex 'set debug-file-directory /srv/sid-armhf/usr/lib/debug' -ex 'set pagination off' -ex 'continue' -ex 'bt' -ex 'continue' -ex 'exit' Something like: Program received signal SIGILL, Illegal instruction. 0x37071dc6 in _GLOBAL__sub_I_SkOpts.cpp () from /srv/sid-armhf/usr/lib/firefox-esr/libxul.so #0 0x37071dc6 in _GLOBAL__sub_I_SkOpts.cpp () from /srv/sid-armhf/usr/lib/firefox-esr/libxul.so #1 0x3f7d144c in call_init (env=0x3f208340, argv=0x3ffffc94, argc=1, l=<optimized out>) at dl-init.c:70 #2 call_init (l=<optimized out>, argc=1, argv=0x3ffffc94, env=0x3f208340) at dl-init.c:26 #3 0x3f7d14f2 in _dl_init (main_map=0x3f245f00, argc=1, argv=0x3ffffc94, env=0x3f208340) at dl-init.c:117 #4 0x3f56664a in _dl_catch_exception () from /srv/sid-armhf/usr/lib/arm-linux-gnueabihf/libc.so.6 #5 0x3f7d5b60 in dl_open_worker (a=0x3fffd7b0) at dl-open.c:808 #6 0x3f566614 in _dl_catch_exception () from /srv/sid-armhf/usr/lib/arm-linux-gnueabihf/libc.so.6 #7 0x3f7d5da2 in _dl_open (file=0x3fffda64 "/srv/sid-armhf/usr/lib/firefox-esr/libxul.so", mode=-2147483391, caller_dlopen=0x4000af81 <_start+4560>, nsid=-2, argc=1, argv=0x3ffffc94, env=0x3f208340) at dl-open.c:884 #8 0x3f4d9da0 in ?? () from /srv/sid-armhf/usr/lib/arm-linux-gnueabihf/libc.so.6
