warning::symbols - systemtap missing-symbols warnings
For some probing operations, where DWARF debugging data is not available,
systemtap needs ELF symbols for the relevant binaries. This allows at least
probe addresses to be calculated, some variables resolved, and with @cast()
and headers, maybe even some types.
- kernel symbol table
- Systemtap may need a linux-build style System.map file to find
addresses of kernel functions/data. It may be possible to create it by
# cp /proc/kallsyms /boot/System.map-`uname -r`
# nm /lib/modules/`uname -r`/build/vmlinux > /boot/System.map-`uname -r`
- On some systems, binaries may be compiled with a subset of symbols useful
for function tracing and backtraces. This 'Minisymbols' is a xz compressed
section labeled .gnu_debugdata. Support for minisymbols relies on elfutils
version 0.156 or later.
- compressed symbols
- On some systems, symbols may be available, but compressed into
.zdebug_* sections. Support for compressed symbols relies on
elfutils version 0.153 or later.