From 45d9b378e85f1b00ac047626827c68589168936c Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Sun, 30 Apr 2017 21:46:45 -0700 Subject: netlink: add NULL-friendly helper for setting extended ACK message As we propagate extended ack reporting throughout various paths in the kernel it may be that the same function is called with the extended ack parameter passed as NULL. One place where that happens is in drivers which have a centralized reconfiguration function called both from ndos and from ethtool_ops. Add a new helper for setting the error message in such conditions. Existing helper is left as is to encourage propagating the ext act fully wherever possible. It also makes it clear in the code which messages may be lost due to ext ack being NULL. Signed-off-by: Jakub Kicinski Acked-by: Daniel Borkmann Signed-off-by: David S. Miller --- include/linux/netlink.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/linux/netlink.h') diff --git a/include/linux/netlink.h b/include/linux/netlink.h index 8d2a8924705c..c20395edf2de 100644 --- a/include/linux/netlink.h +++ b/include/linux/netlink.h @@ -92,6 +92,14 @@ struct netlink_ext_ack { (extack)->_msg = _msg; \ } while (0) +#define NL_MOD_TRY_SET_ERR_MSG(extack, msg) do { \ + static const char _msg[] = KBUILD_MODNAME ": " msg; \ + struct netlink_ext_ack *_extack = (extack); \ + \ + if (_extack) \ + _extack->_msg = _msg; \ +} while (0) + extern void netlink_kernel_release(struct sock *sk); extern int __netlink_change_ngroups(struct sock *sk, unsigned int groups); extern int netlink_change_ngroups(struct sock *sk, unsigned int groups); -- cgit