I'm looking at various string constructs in (for example) drivers/dahdi/dahdi-base.c:

strncat(vi.echo_canceller + strlen(vi.echo_canceller),
        ec_name, space);

which doesn't make sense. strncat(s1, s2, n) already finds the strlen(s1) when doing the append. This is redundant. Either do:

strncat(vi.echo_canceller,
        ec_name, space);

or:

strncpy(vi.echo_canceller + strlen(vi.echo_canceller),
        ec_name, space);