xdp: remove redundant argument to trace_xdp_redirect

Supplying the action argument XDP_REDIRECT to the tracepoint xdp_redirect
is redundant as it is only called in-case this action was specified.

Remove the argument, but keep "act" member of the tracepoint struct and
populate it with XDP_REDIRECT.  This makes it easier to write a common bpf_prog
processing events.

Signed-off-by: Jesper Dangaard Brouer <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: netoptimizer

include/trace/events/xdp.h

@@ -52,10 +52,10 @@ TRACE_EVENT(xdp_exception,
 TRACE_EVENT(xdp_redirect,
 
 	TP_PROTO(const struct net_device *dev,
-		 const struct bpf_prog *xdp, u32 act,
+		 const struct bpf_prog *xdp,
 		 int to_index, int err),
 
-	TP_ARGS(dev, xdp, act, to_index, err),
+	TP_ARGS(dev, xdp, to_index, err),
 
 	TP_STRUCT__entry(
 		__array(u8, prog_tag, 8)
@@ -68,7 +68,7 @@ TRACE_EVENT(xdp_redirect,
 	TP_fast_assign(
 		BUILD_BUG_ON(sizeof(__entry->prog_tag) != sizeof(xdp->tag));
 		memcpy(__entry->prog_tag, xdp->tag, sizeof(xdp->tag));
-		__entry->act		= act;
+		__entry->act		= XDP_REDIRECT;
 		__entry->ifindex	= dev->ifindex;
 		__entry->to_index	= to_index;
 		__entry->err		= err;

net/core/filter.c

@@ -2524,7 +2524,7 @@ static int xdp_do_redirect_map(struct net_device *dev, struct xdp_buff *xdp,
 	if (likely(!err))
 		ri->map_to_flush = map;
 out:
-	trace_xdp_redirect(dev, xdp_prog, XDP_REDIRECT, index, err);
+	trace_xdp_redirect(dev, xdp_prog, index, err);
 	return err;
 }
 
@@ -2548,7 +2548,7 @@ int xdp_do_redirect(struct net_device *dev, struct xdp_buff *xdp,
 
 	err = __bpf_tx_xdp(fwd, NULL, xdp, 0);
 out:
-	trace_xdp_redirect(dev, xdp_prog, XDP_REDIRECT, index, err);
+	trace_xdp_redirect(dev, xdp_prog, index, err);
 	return err;
 }
 EXPORT_SYMBOL_GPL(xdp_do_redirect);
@@ -2582,7 +2582,7 @@ int xdp_do_generic_redirect(struct net_device *dev, struct sk_buff *skb,
 
 	skb->dev = fwd;
 out:
-	trace_xdp_redirect(dev, xdp_prog, XDP_REDIRECT, index, err);
+	trace_xdp_redirect(dev, xdp_prog, index, err);
 	return err;
 }
 EXPORT_SYMBOL_GPL(xdp_do_generic_redirect);