-
Jesper Dangaard Brouer authored
As pointed out by Michael, commit 1c601d82 ("bpf: cpumap xdp_buff to skb conversion and allocation") contains a classical example of the potential lost wake-up problem. We need to recheck the condition __ptr_ring_empty() after changing current->state to TASK_INTERRUPTIBLE, this avoids a race between wake_up_process() and schedule(). After this, a race with wake_up_process() will simply change the state to TASK_RUNNING, and the schedule() call not really put us to sleep. Fixes: 1c601d82 ("bpf: cpumap xdp_buff to skb conversion and allocation") Reported-by:
"Michael S. Tsirkin" <mst@redhat.com> Signed-off-by:
Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by:
David S. Miller <davem@davemloft.net>
31749468