• Josef Bacik's avatar
    bpf: add a bpf_override_function helper · 9802d865
    Josef Bacik authored
    Error injection is sloppy and very ad-hoc.  BPF could fill this niche
    perfectly with it's kprobe functionality.  We could make sure errors are
    only triggered in specific call chains that we care about with very
    specific situations.  Accomplish this with the bpf_override_funciton
    helper.  This will modify the probe'd callers return value to the
    specified value and set the PC to an override function that simply
    returns, bypassing the originally probed function.  This gives us a nice
    clean way to implement systematic error injection for all of our code
    paths.
    Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
    Acked-by: default avatarIngo Molnar <mingo@kernel.org>
    Signed-off-by: default avatarJosef Bacik <jbacik@fb.com>
    Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
    9802d865
Kconfig 93.3 KB