• Jan Kara's avatar
    vfs: Avoid softlockups with sendfile(2) · c2489e07
    Jan Kara authored
    The following test program from Dmitry can cause softlockups or RCU
    stalls as it copies 1GB from tmpfs into eventfd and we don't have any
    scheduling point at that path in sendfile(2) implementation:
            int r1 = eventfd(0, 0);
            int r2 = memfd_create("", 0);
            unsigned long n = 1<<30;
            fallocate(r2, 0, 0, n);
            sendfile(r1, r2, 0, n);
    Add cond_resched() into __splice_from_pipe() to fix the problem.
    CC: Dmitry Vyukov <dvyukov@google.com>
    CC: stable@vger.kernel.org
    Signed-off-by: default avatarJan Kara <jack@suse.cz>
    Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
splice.c 46.4 KB