From: Daniel Borkmann Date: Wed, 13 Feb 2013 01:03:50 +0000 (+0000) Subject: net: sctp: add build check for sctp_sf_eat_sack_6_2/jsctp_sf_eat_sack X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=22222997;p=linux-beck.git net: sctp: add build check for sctp_sf_eat_sack_6_2/jsctp_sf_eat_sack In order to avoid any future surprises of kernel panics due to jprobes function mismatches (as e.g. fixed in 4cb9d6eaf85ecd: sctp: jsctp_sf_eat_sack: fix jprobes function signature mismatch), we should check both function types during build and scream loudly if they do not match. __same_type resolves to __builtin_types_compatible_p, which is 1 in case both types are the same and 0 otherwise, qualifiers are ignored. Tested by myself. Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller --- diff --git a/net/sctp/probe.c b/net/sctp/probe.c index 4eaaaf68e5b7..261b7b9858a4 100644 --- a/net/sctp/probe.c +++ b/net/sctp/probe.c @@ -183,6 +183,13 @@ static __init int sctpprobe_init(void) { int ret = -ENOMEM; + /* Warning: if the function signature of sctp_sf_eat_sack_6_2, + * has been changed, you also have to change the signature of + * jsctp_sf_eat_sack, otherwise you end up right here! + */ + BUILD_BUG_ON(__same_type(sctp_sf_eat_sack_6_2, + jsctp_sf_eat_sack) == 0); + init_waitqueue_head(&sctpw.wait); spin_lock_init(&sctpw.lock); if (kfifo_alloc(&sctpw.fifo, bufsize, GFP_KERNEL))