The LD_DEBUG environment variable (2012) (bnikolic.co.uk)
82 points by tanelpoder 4 days ago
account42 3 days ago
Used this once to debug an issue where it turned out unwanted exports in one library A where used to satisfy imports in another library B and thus preventing library A from being unloaded. Fun times.
The ldd command is also essentially just a wrapper script that sets LD_* variables that get the dynamic loader to do all the real work.
alschwalm 4 days ago
LD_AUDIT is another one worth knowing about (though I admittedly use it less often than LD_DEBUG) https://man7.org/linux/man-pages/man7/rtld-audit.7.html
rramadass 3 days ago
A couple of posts on how to use LD_AUDIT;
Leveraging LD_AUDIT to Beat the Traditional Linux Library Preloading Technique - https://www.sentinelone.com/labs/leveraging-ld_audit-to-beat...
rtld-audit and LD_AUDIT - https://vsoch.github.io/2021/ldaudit/
rramadass 3 days ago
Do you know where i can find a list of all LD_XXX environment variables?
zorgmonkey 3 days ago
The man page ld.so has ENVIRONMENT section that looks pretty good.
Otherwise one of the most reliable options is to simply grep the source code for calls to getenv, I would not be that surprised if their are some extra ones that are undocumented.
rramadass 3 days ago
BobbyTables2 3 days ago
Read The Fine Manpage
ld.so