From 4843b93c96ae5043c6279c4ec6fcd8ee3866ff5b Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Tue, 3 Mar 2009 23:37:30 -0800 Subject: [PATCH] netlink: invert error code in netlink_set_err() The callers of netlink_set_err() currently pass a negative value as parameter for the error code. However, sk->sk_err wants a positive error value. Without this patch, skb_recv_datagram() called by netlink_recvmsg() may return a positive value to report an error. Another choice to fix this is to change callers to pass a positive error value, but this seems a bit inconsistent and error prone to me. Indeed, the callers of netlink_set_err() assumed that the (usual) negative value for error codes was fine before this patch :). This patch also includes some documentation in docbook format for netlink_set_err() to avoid this sort of confusion. Signed-off-by: Pablo Neira Ayuso Signed-off-by: David S. Miller --- net/netlink/af_netlink.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 9eb895c7a2a9..3ae3cb816563 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -1084,6 +1084,13 @@ out: return 0; } +/** + * netlink_set_err - report error to broadcast listeners + * @ssk: the kernel netlink socket, as returned by netlink_kernel_create() + * @pid: the PID of a process that we want to skip (if any) + * @groups: the broadcast group that will notice the error + * @code: error code, must be negative (as usual in kernelspace) + */ void netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code) { struct netlink_set_err_data info; @@ -1093,7 +1100,8 @@ void netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code) info.exclude_sk = ssk; info.pid = pid; info.group = group; - info.code = code; + /* sk->sk_err wants a positive error value */ + info.code = -code; read_lock(&nl_table_lock); -- 2.20.1