From 262f9d811c7608f1e74258ceecfe1fa213bdf912 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 5 Oct 2018 19:38:46 -0700 Subject: bpf: do not blindly change rlimit in reuseport net selftest If the current process has unlimited RLIMIT_MEMLOCK, we should should leave it as is. Fixes: 941ff6f11c02 ("bpf: fix rlimit in reuseport net selftest") Signed-off-by: John Sperbeck Signed-off-by: Eric Dumazet Acked-by: Daniel Borkmann Signed-off-by: Daniel Borkmann --- tools/testing/selftests/net/reuseport_bpf.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/tools/testing/selftests/net/reuseport_bpf.c b/tools/testing/selftests/net/reuseport_bpf.c index cad14cd0ea92..b5277106df1f 100644 --- a/tools/testing/selftests/net/reuseport_bpf.c +++ b/tools/testing/selftests/net/reuseport_bpf.c @@ -437,14 +437,19 @@ void enable_fastopen(void) } } -static struct rlimit rlim_old, rlim_new; +static struct rlimit rlim_old; static __attribute__((constructor)) void main_ctor(void) { getrlimit(RLIMIT_MEMLOCK, &rlim_old); - rlim_new.rlim_cur = rlim_old.rlim_cur + (1UL << 20); - rlim_new.rlim_max = rlim_old.rlim_max + (1UL << 20); - setrlimit(RLIMIT_MEMLOCK, &rlim_new); + + if (rlim_old.rlim_cur != RLIM_INFINITY) { + struct rlimit rlim_new; + + rlim_new.rlim_cur = rlim_old.rlim_cur + (1UL << 20); + rlim_new.rlim_max = rlim_old.rlim_max + (1UL << 20); + setrlimit(RLIMIT_MEMLOCK, &rlim_new); + } } static __attribute__((destructor)) void main_dtor(void) -- cgit v1.2.3-59-g8ed1b From cee271678d0e3177a25d0fcb2fa5e051d48e4262 Mon Sep 17 00:00:00 2001 From: Björn Töpel Date: Mon, 8 Oct 2018 19:40:16 +0200 Subject: xsk: do not call synchronize_net() under RCU read lock MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The XSKMAP update and delete functions called synchronize_net(), which can sleep. It is not allowed to sleep during an RCU read section. Instead we need to make sure that the sock sk_destruct (xsk_destruct) function is asynchronously called after an RCU grace period. Setting the SOCK_RCU_FREE flag for XDP sockets takes care of this. Fixes: fbfc504a24f5 ("bpf: introduce new bpf AF_XDP map type BPF_MAP_TYPE_XSKMAP") Reported-by: Eric Dumazet Signed-off-by: Björn Töpel Acked-by: Song Liu Signed-off-by: Daniel Borkmann --- kernel/bpf/xskmap.c | 10 ++-------- net/xdp/xsk.c | 2 ++ 2 files changed, 4 insertions(+), 8 deletions(-) diff --git a/kernel/bpf/xskmap.c b/kernel/bpf/xskmap.c index 9f8463afda9c..47147c9e184d 100644 --- a/kernel/bpf/xskmap.c +++ b/kernel/bpf/xskmap.c @@ -192,11 +192,8 @@ static int xsk_map_update_elem(struct bpf_map *map, void *key, void *value, sock_hold(sock->sk); old_xs = xchg(&m->xsk_map[i], xs); - if (old_xs) { - /* Make sure we've flushed everything. */ - synchronize_net(); + if (old_xs) sock_put((struct sock *)old_xs); - } sockfd_put(sock); return 0; @@ -212,11 +209,8 @@ static int xsk_map_delete_elem(struct bpf_map *map, void *key) return -EINVAL; old_xs = xchg(&m->xsk_map[k], NULL); - if (old_xs) { - /* Make sure we've flushed everything. */ - synchronize_net(); + if (old_xs) sock_put((struct sock *)old_xs); - } return 0; } diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index 4e937cd7c17d..661504042d30 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -744,6 +744,8 @@ static int xsk_create(struct net *net, struct socket *sock, int protocol, sk->sk_destruct = xsk_destruct; sk_refcnt_debug_inc(sk); + sock_set_flag(sk, SOCK_RCU_FREE); + xs = xdp_sk(sk); mutex_init(&xs->mutex); spin_lock_init(&xs->tx_completion_lock); -- cgit v1.2.3-59-g8ed1b