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 4cb9d6eaf8: 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 <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Daniel Borkmann 2013-02-13 01:03:50 +00:00 committed by David S. Miller
parent 1e55817463
commit 2222299748

View File

@ -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))