Michael Stahl <mstahl@xxxxxxxxxx> writes: >> Symbol interposition is used a lot for very useful features, blocking >> interposition would break a lot of stuff. > > really? i've always thought that it was only useful for libc symbols, > but maybe that's because i don't work on base OS stuff. I'd guess most uses are not to do with base OS stuff. It's important in a lot of cases in research-type computing support, though that doesn't seem to count for much. Profiling and other instrumentation in the high performance computing world (where it's taken quite seriously) typically uses LD_PRELOAD libraries. For instance, that's essentially required by useful implementations of the mechanisms defined by the MPI standard, as embodied in the openmpi and scorep-openmpi Fedora packages, inter alia. There are varied other HPC uses, like compensating for filesystem deficiencies, and I've known (non-Unix) library preloads as an extension mechanism since the 80s. [Yes, there's a potential problem with users trashing the "system" items you'd like in LD_PRELOAD.] -- devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
