I used to do tons with LD_PRELOAD
I used to do tons with LD_PRELOAD
Posted Feb 13, 2024 20:53 UTC (Tue) by davecb (subscriber, #1574)Parent article: A look at dynamic linking
In a previous life, interposing things between caller and recipient was a favourite task.
We used it to create programs like a low-overhead strace, a performance measurement tool that used unmodified binaries, and, as a demo, a Linux library profiler, https://github.com/davecb/libprof
We used it to create programs like a low-overhead strace, a performance measurement tool that used unmodified binaries, and, as a demo, a Linux library profiler, https://github.com/davecb/libprof
Posted Feb 21, 2024 12:22 UTC (Wed)
by nix (subscriber, #2304)
[Link]
(In practice this excellent feature is rarely used, alas.
I used to do tons with LD_PRELOAD
Nowadays, if you want to do something like that and also explore exciting underused parts of ld.so, the thing to try is LD_AUDIT libraries. These are loaded in a new dlmopen namespace, so they can rely on other shared libraries and the like, making it a lot easier to write the things than it is to write an LD_PRELOADed profiler.