• Willem de Bruijn's avatar
    sock: deduplicate errqueue dequeue · 364a9e93
    Willem de Bruijn authored
    sk->sk_error_queue is dequeued in four locations. All share the
    exact same logic. Deduplicate.
    
    Also collapse the two critical sections for dequeue (at the top of
    the recv handler) and signal (at the bottom).
    
    This moves signal generation for the next packet forward, which should
    be harmless.
    
    It also changes the behavior if the recv handler exits early with an
    error. Previously, a signal for follow-up packets on the errqueue
    would then not be scheduled. The new behavior, to always signal, is
    arguably a bug fix.
    
    For rxrpc, the change causes the same function to be called repeatedly
    for each queued packet (because the recv handler == sk_error_report).
    It is likely that all packets will fail for the same reason (e.g.,
    memory exhaustion).
    
    This code runs without sk_lock held, so it is not safe to trust that
    sk->sk_err is immutable inbetween releasing q->lock and the subsequent
    test. Introduce int err just to avoid this potential race.
    Signed-off-by: default avatarWillem de Bruijn <willemb@google.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    364a9e93
datagram.c 21.8 KB