Sentinel issues

[larseggert]

I get a ton of messages like this when running perf on Linux to take a Firefox sample:

addr2line /home/lars/.debug/.build-id/ae/24c1c86da6dcb759e722e951b9b5e8/elf: could not read sentinel record
addr2line /home/lars/.debug/.build-id/ae/24c1c86da6dcb759e722e951b9b5e8/elf: unexpected record instead of sentinel

I take the sample with

perf record -F 997 --call-graph dwarf,65528 -e cpu-clock:uk -o ~/perf.data -- /home/lars/firefox/main/obj-aarch64-unknown-linux-gnu/dist/bin/firefox --no-remote

[philipc]

Does addr2line --all -afi -e /home/lars/.debug/.build-id/ae/24c1c86da6dcb759e722e951b9b5e8/elf > /dev/null show any errors?

I probably need some steps to reproduce, please. Those are error messages produced by perf, not this crate. It may be an error in the output of this crate, but that isn't enough information for me to go on.

[larseggert]

No errors with that command.

I don't know if I have an easy reproducer. This is taking a perf trace of a full Firefox build.

I just reran this, and after quitting Firefox, perf and/or addr2ine were stuck. After a minute or two, I hit Ctrl-C, and got a ton of these messages:

addr2line /home/lars/.debug/.build-id/59/be1adbf545f17a19deae7bd5c46e9e/elf: could not send request

[philipc]

That's another error from perf, not this crate: https://github.com/torvalds/linux/blob/0031c06807cfa8aa51a759ff8aa09e1aa48149af/tools/perf/util/addr2line.c#L334

[larseggert]

OK. Sorry, that wasn't obvious from the line.

[philipc]

Can you confirm that you are using the addr2line from this crate, and not the standard binutils addr2line?

[larseggert]

It's at least the first in my path. I assume that would make perf use it?

[philipc]

Yes, I think that should be enough.