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

Alexei Starovoitov says:

====================
pull-request: bpf 2020-11-06

1) Pre-allocated per-cpu hashmap needs to zero-fill reused element, from David.

2) Tighten bpf_lsm function check, from KP.

3) Fix bpftool attaching to flow dissector, from Lorenz.

4) Use -fno-gcse for the whole kernel/bpf/core.c instead of function attribute, from Ard.

* git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  bpf: Update verification logic for LSM programs
  bpf: Zero-fill re-used per-cpu map element
  bpf: BPF_PRELOAD depends on BPF_SYSCALL
  tools/bpftool: Fix attaching flow dissector
  libbpf: Fix possible use after free in xsk_socket__delete
  libbpf: Fix null dereference in xsk_socket__delete
  libbpf, hashmap: Fix undefined behavior in hash_bits
  bpf: Don't rely on GCC __attribute__((optimize)) to disable GCSE
  tools, bpftool: Remove two unused variables.
  tools, bpftool: Avoid array index warnings.
  xsk: Fix possible memory leak at socket close
  bpf: Add struct bpf_redir_neigh forward declaration to BPF helper defs
  samples/bpf: Set rlimit for memlock to infinity in all samples
  bpf: Fix -Wshadow warnings
  selftest/bpf: Fix profiler test using CO-RE relocation for enums
====================

Link: https://lore.kernel.org/r/20201106221759.24143-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

2 files changed, 7 insertions, 3 deletions

diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index b71a32eeae65..cfbec3989a76 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -1146,7 +1146,8 @@ static void xsk_destruct(struct sock *sk)
 	if (!sock_flag(sk, SOCK_DEAD))
 		return;
 
-	xp_put_pool(xs->pool);
+	if (!xp_put_pool(xs->pool))
+		xdp_put_umem(xs->umem);
 
 	sk_refcnt_debug_dec(sk);
 }
diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c
index 64c9e55d4d4e..8a3bf4e1318e 100644
--- a/net/xdp/xsk_buff_pool.c
+++ b/net/xdp/xsk_buff_pool.c
@@ -251,15 +251,18 @@ void xp_get_pool(struct xsk_buff_pool *pool)
 	refcount_inc(&pool->users);
 }
 
-void xp_put_pool(struct xsk_buff_pool *pool)
+bool xp_put_pool(struct xsk_buff_pool *pool)
 {
 	if (!pool)
-		return;
+		return false;
 
 	if (refcount_dec_and_test(&pool->users)) {
 		INIT_WORK(&pool->work, xp_release_deferred);
 		schedule_work(&pool->work);
+		return true;
 	}
+
+	return false;
 }
 
 static struct xsk_dma_map *xp_find_dma_map(struct xsk_buff_pool *pool)