Commit fb7dd8bc authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Daniel Borkmann
Browse files

bpf: Refactor BPF_PROG_RUN into a function 



Turn BPF_PROG_RUN into a proper always inlined function. No functional and
performance changes are intended, but it makes it much easier to understand
what's going on with how BPF programs are actually get executed. It's more
obvious what types and callbacks are expected. Also extra () around input
parameters can be dropped, as well as `__` variable prefixes intended to avoid
naming collisions, which makes the code simpler to read and write.

This refactoring also highlighted one extra issue. BPF_PROG_RUN is both
a macro and an enum value (BPF_PROG_RUN == BPF_PROG_TEST_RUN). Turning
BPF_PROG_RUN into a function causes naming conflict compilation error. So
rename BPF_PROG_RUN into lower-case bpf_prog_run(), similar to
bpf_prog_run_xdp(), bpf_prog_run_pin_on_cpu(), etc. All existing callers of
BPF_PROG_RUN, the macro, are switched to bpf_prog_run() explicitly.

Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarYonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210815070609.987780-2-andrii@kernel.org
parent 1bda52f8

Documentation/networking/filter.rst

+2 −2
Original line number Diff line number Diff line
@@ -638,8 +638,8 @@ extension, PTP dissector/classifier, and much more. They are all internally 
converted by the kernel into the new instruction set representation and run

in the eBPF interpreter. For in-kernel handlers, this all works transparently

by using bpf_prog_create() for setting up the filter, resp.

bpf_prog_destroy() for destroying it. The macro

BPF_PROG_RUN(filter, ctx) transparently invokes eBPF interpreter or JITed

bpf_prog_destroy() for destroying it. The function

bpf_prog_run(filter, ctx) transparently invokes eBPF interpreter or JITed

code to run the filter. 'filter' is a pointer to struct bpf_prog that we

got from bpf_prog_create(), and 'ctx' the given context (e.g.

skb pointer). All constraints and restrictions from bpf_check_classic() apply

drivers/media/rc/bpf-lirc.c

+1 −1
Original line number Diff line number Diff line
@@ -217,7 +217,7 @@ void lirc_bpf_run(struct rc_dev *rcdev, u32 sample) 
	raw->bpf_sample = sample;



	if (raw->progs)

		BPF_PROG_RUN_ARRAY(raw->progs, &raw->bpf_sample, BPF_PROG_RUN);

		BPF_PROG_RUN_ARRAY(raw->progs, &raw->bpf_sample, bpf_prog_run);

}



/*

drivers/net/ppp/ppp_generic.c

+4 −4
Original line number Diff line number Diff line
@@ -1744,7 +1744,7 @@ ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) 
		   a four-byte PPP header on each packet */

		*(u8 *)skb_push(skb, 2) = 1;

		if (ppp->pass_filter &&

		    BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {

		    bpf_prog_run(ppp->pass_filter, skb) == 0) {

			if (ppp->debug & 1)

				netdev_printk(KERN_DEBUG, ppp->dev,

					      "PPP: outbound frame "
@@ -1754,7 +1754,7 @@ ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) 
		}

		/* if this packet passes the active filter, record the time */

		if (!(ppp->active_filter &&

		      BPF_PROG_RUN(ppp->active_filter, skb) == 0))

		      bpf_prog_run(ppp->active_filter, skb) == 0))

			ppp->last_xmit = jiffies;

		skb_pull(skb, 2);

#else
@@ -2468,7 +2468,7 @@ ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) 


			*(u8 *)skb_push(skb, 2) = 0;

			if (ppp->pass_filter &&

			    BPF_PROG_RUN(ppp->pass_filter, skb) == 0) {

			    bpf_prog_run(ppp->pass_filter, skb) == 0) {

				if (ppp->debug & 1)

					netdev_printk(KERN_DEBUG, ppp->dev,

						      "PPP: inbound frame "
@@ -2477,7 +2477,7 @@ ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) 
				return;

			}

			if (!(ppp->active_filter &&

			      BPF_PROG_RUN(ppp->active_filter, skb) == 0))

			      bpf_prog_run(ppp->active_filter, skb) == 0))

				ppp->last_recv = jiffies;

			__skb_pull(skb, 2);

		} else

drivers/net/team/team_mode_loadbalance.c

+1 −1
Original line number Diff line number Diff line
@@ -197,7 +197,7 @@ static unsigned int lb_get_skb_hash(struct lb_priv *lb_priv, 
	fp = rcu_dereference_bh(lb_priv->fp);

	if (unlikely(!fp))

		return 0;

	lhash = BPF_PROG_RUN(fp, skb);

	lhash = bpf_prog_run(fp, skb);

	c = (char *) &lhash;

	return c[0] ^ c[1] ^ c[2] ^ c[3];

}

include/linux/bpf.h

+1 −1
Original line number Diff line number Diff line
@@ -1103,7 +1103,7 @@ u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, 
/* an array of programs to be executed under rcu_lock.

 *

 * Typical usage:

 * ret = BPF_PROG_RUN_ARRAY(&bpf_prog_array, ctx, BPF_PROG_RUN);

 * ret = BPF_PROG_RUN_ARRAY(&bpf_prog_array, ctx, bpf_prog_run);

 *

 * the structure returned by bpf_prog_array_alloc() should be populated

 * with program pointers and the last pointer must be NULL.