WARNING::SYMBOLS(7stap)

💖 NAME 💖

warning::symbols — the systemtap missing-symbols warnings, aka the "bestie where are ur symbols" page 💅

✨ DESCRIPTION ✨

okay so listen. sometimes systemtap is out here trying to do some probing operations, and the DWARF debugging data just… isn't there. not a vibe. when that happens, systemtap needs ELF symbols for the relevant binaries instead.

and honestly? that's still giving a lot. with those symbols you get at least:

• probe addresses getting calculated 🎯
• some variables resolved 🔍
• and if you've got @cast() and headers in the mix, maybe even some types 👑

🧚 kernel symbol table

systemtap may need a linux-build style System.map file to find the addresses of kernel functions/data. no big deal, you might be able to hand-make one, lowkey:

% su
# cp /proc/kallsyms /boot/System.map-`uname -r`
or
# nm /lib/modules/`uname -r`/build/vmlinux > /boot/System.map-`uname -r`

fr fr, just pick whichever line works for ur situation.</purl> (💀 not the su though, that's mandatory bestie)

🦋 minisymbols

so on some systems, binaries get compiled with just a subset of symbols — the ones that are useful for function tracing and backtraces. that's what they call 'Minisymbols': an xz compressed section labeled .gnu_debugdata.

⚠️ heads up: support for minisymbols relies on elfutils version 0.156 or later. older than that and it's giving nothing, sorry.

🌸 compressed symbols

and on <em>other</em> systems, the symbols might totally be there, just compressed into .zdebug_* sections. sneaky but fine.

⚠️ this one relies on elfutils version 0.153 or later. yes the number is different, don't mix them up bestie 🙈

🎀 SEE ALSO 🎀

• stap(1)
• stappaths(7)
• strip(1)
• warning::debuginfo(7stap)
• error::dwarf(7stap)
• error::reporting(7stap)
• http://fedoraproject.org/wiki/Features/MiniDebugInfo

and that's the whole page bestie, no cap. 🫶 this was warning::symbols straight outta the 7stap manual section, so if u ever see the footer WARNING::SYMBOLS(7stap) floating around at the bottom of a terminal, that's just this page saying bye 👋✨ mwah, go resolve some symbols 💖