• Tejun Heo's avatar
    freezer: kill unused set_freezable_with_signal() · 34b087e4
    Tejun Heo authored
    There's no in-kernel user of set_freezable_with_signal() left.  Mixing
    TIF_SIGPENDING with kernel threads can lead to nasty corner cases as
    kernel threads never travel signal delivery path on their own.
    e.g. the current implementation is buggy in the cancelation path of
    __thaw_task().  It calls recalc_sigpending_and_wake() in an attempt to
    clear TIF_SIGPENDING but the function never clears it regardless of
    sigpending state.  This means that signallable freezable kthreads may
    continue executing with !freezing() && stuck TIF_SIGPENDING, which can
    be troublesome.
    This patch removes set_freezable_with_signal() along with
    PF_FREEZER_NOSIG and recalc_sigpending*() calls in freezer.  User
    tasks get TIF_SIGPENDING, kernel tasks get woken up and the spurious
    sigpending is dealt with in the usual signal delivery path.
    Signed-off-by: default avatarTejun Heo <tj@kernel.org>
    Acked-by: default avatarOleg Nesterov <oleg@redhat.com>
freezer.c 4.22 KB