Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Alexei Starovoitov says:

====================
pull-request: bpf-next 2021-03-09

The following pull-request contains BPF updates for your *net-next* tree.

We've added 90 non-merge commits during the last 17 day(s) which contain
a total of 114 files changed, 5158 insertions(+), 1288 deletions(-).

The main changes are:

1) Faster bpf_redirect_map(), from Björn.

2) skmsg cleanup, from Cong.

3) Support for floating point types in BTF, from Ilya.

4) Documentation for sys_bpf commands, from Joe.

5) Support for sk_lookup in bpf_prog_test_run, form Lorenz.

6) Enable task local storage for tracing programs, from Song.

7) bpf_for_each_map_elem() helper, from Yonghong.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 12 deletions

diff --git a/tools/lib/bpf/xsk.h b/tools/lib/bpf/xsk.h
index e9f121f5d129..a9fdea87b5cd 100644
--- a/tools/lib/bpf/xsk.h
+++ b/tools/lib/bpf/xsk.h
@@ -96,7 +96,8 @@ static inline __u32 xsk_prod_nb_free(struct xsk_ring_prod *r, __u32 nb)
 	 * this function. Without this optimization it whould have been
 	 * free_entries = r->cached_prod - r->cached_cons + r->size.
 	 */
-	r->cached_cons = *r->consumer + r->size;
+	r->cached_cons = libbpf_smp_load_acquire(r->consumer);
+	r->cached_cons += r->size;
 
 	return r->cached_cons - r->cached_prod;
 }
@@ -106,7 +107,7 @@ static inline __u32 xsk_cons_nb_avail(struct xsk_ring_cons *r, __u32 nb)
 	__u32 entries = r->cached_prod - r->cached_cons;
 
 	if (entries == 0) {
-		r->cached_prod = *r->producer;
+		r->cached_prod = libbpf_smp_load_acquire(r->producer);
 		entries = r->cached_prod - r->cached_cons;
 	}
 
@@ -129,9 +130,7 @@ static inline void xsk_ring_prod__submit(struct xsk_ring_prod *prod, __u32 nb)
 	/* Make sure everything has been written to the ring before indicating
 	 * this to the kernel by writing the producer pointer.
 	 */
-	libbpf_smp_wmb();
-
-	*prod->producer += nb;
+	libbpf_smp_store_release(prod->producer, *prod->producer + nb);
 }
 
 static inline __u32 xsk_ring_cons__peek(struct xsk_ring_cons *cons, __u32 nb, __u32 *idx)
@@ -139,11 +138,6 @@ static inline __u32 xsk_ring_cons__peek(struct xsk_ring_cons *cons, __u32 nb, __
 	__u32 entries = xsk_cons_nb_avail(cons, nb);
 
 	if (entries > 0) {
-		/* Make sure we do not speculatively read the data before
-		 * we have received the packet buffers from the ring.
-		 */
-		libbpf_smp_rmb();
-
 		*idx = cons->cached_cons;
 		cons->cached_cons += entries;
 	}
@@ -161,9 +155,8 @@ static inline void xsk_ring_cons__release(struct xsk_ring_cons *cons, __u32 nb)
 	/* Make sure data has been read before indicating we are done
 	 * with the entries by updating the consumer pointer.
 	 */
-	libbpf_smp_rwmb();
+	libbpf_smp_store_release(cons->consumer, *cons->consumer + nb);
 
-	*cons->consumer += nb;
 }
 
 static inline void *xsk_umem__get_data(void *umem_area, __u64 addr)