git: rtld: Add support for preinit, init, and fini arrays

John Marino marino at
Sat Feb 11 12:04:28 PST 2012

commit b28bf640312db2b299faff75052fbb01d67fd821
Author: John Marino <draco at>
Date:   Sat Feb 11 20:17:51 2012 +0100

    rtld: Add support for preinit, init, and fini arrays
    As far as I can tell, all BSDs limit their ELF executable file
    initialization and termination to the .init and .fini sections.  In
    contrast, Linux has additionally supported the .preinit_array,
    .init_array, and .fini_array sections for over a decade through glibc.
    With this commit, DragonFly becomes the first BSD to support these
    arrays of function pointers.  It was tested using test cases taken from
    glibc, gnu ld linker, and the gold linker.
    For the main executable file, the .init_array and .fini_array sections
    are handled by crt1, just like .init and .fini are.  In the case of
    a statically linked binary, the .preinit_array section is also handled
    by crt1.  The real-time linker handles the .init_array and .fini_array
    sections for dynamically shared objects (libraries) and .preinit_array
    for dynamically-linked binaries.  There are no .preinit_array sections
    in the DSOs per standard.
    These sections are described by the System V Application Binary Interface
    The .init_array and .fini_array handling by rtld was reviewed by
    Konstantin Belousov.

Summary of changes:
 lib/csu/i386/crt1_c.c                  |   30 +++++++
 lib/csu/x86_64/crt1.c                  |   30 +++++++
 libexec/rtld-elf/i386/rtld_machdep.h   |    3 +
 libexec/rtld-elf/rtld.c                |  133 +++++++++++++++++++++++++++++---
 libexec/rtld-elf/rtld.h                |    7 ++
 libexec/rtld-elf/x86_64/rtld_machdep.h |    3 +
 6 files changed, 194 insertions(+), 12 deletions(-)

DragonFly BSD source repository

More information about the Commits mailing list