On Tue, 2022-03-22 at 09:59 -0500, Benjamin Marzinski wrote: > > So all of the exported symbols from libmultipath are weak? Good to > know. No, "weak" has a special meaning. For dynamic linking, it's default behavior to resolve symbols by name and use the first definition encountered. This means that a symbol in a shared library will always be overridden by a symbol of the same name in the main executable. "When resolving symbolic references, the dynamic linker examines the symbol tables with a breadth-first search. That is, it first looks at the symbol table of the executable program itself, then at the symbol tables of the DT_NEEDED entries (in order), then at the second level DT_NEEDED entries, and so on." ([1], III, p. 2-12). The "weak" attribute only matters during static linking ([1], III, p. 1-5). See also the description of LD_DYNAMIC_WEAK in ld.so(8) [2]. I didn't understand this clearly before. And the documentation, in particular the explanation of the "weak" attribute in the gcc docs, is misleading, because it doesn't explain the difference between static and dynamic linking [3]. Regards Martin [1] https://refspecs.linuxfoundation.org/elf/elf.pdf [2] https://man7.org/linux/man-pages/man8/ld.so.8.html [3] https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#Common-Function-Attributes -- dm-devel mailing list dm-devel@xxxxxxxxxx https://listman.redhat.com/mailman/listinfo/dm-devel
