L1 Solib Loader EN

Language: English ｜ L1-Solib-Loader

L1 guide: the shared-object loader

libs/ld_so.c - a real dynamic loader for the kernel, used by L1 modules and the dynamic-linking user programs alike.

The surface (l1/l1_wp8b.h)

elf_load_dynamic(elf_data, size, name)    -> load + relocate
ldso_run()                                 -> run loaded objects' init
so_load(name, flags) / so_unload(handle)
symbol_resolve(handle, name)
dlopen_impl(name, flags) / dlsym_impl(handle, name) / dlclose_impl(handle)
reloc_apply(rela, count, base, ...)
elf_get_needed(elf_data, size, ...)

What it handles

ELF dynamic objects: DT_NEEDED chains (elf_get_needed), symbol tables, relocation processing (reloc_apply - R_X86_64_RELATIVE/ GLOB_DAT/JUMP_SLOT/64 families), init arrays at ldso_run, and unload with reference handling.

The proof it works

The userprogs/ fleet exercises every corner from ring 3: run dyn_hello, run so_test, run dlsym_test, run pie_test, run reloc_test - and ext_wp8b_selftest() self-checks the loader in-kernel. If your module loads through this path, these are your regression anchors.

Position independence

PIE objects relocate through the same reloc_apply; the loader's base assignment is what makes -fno-pie kernel code and PIE modules coexist - see the pie_test source for the exact relocation mix a module may carry.