From df561f6688fef775baa341a0f5d960becd248b11 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Sun, 23 Aug 2020 17:36:59 -0500 Subject: treewide: Use fallthrough pseudo-keyword Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva --- net/sctp/ipv6.c | 2 +- net/sctp/outqueue.c | 6 +++--- net/sctp/sm_make_chunk.c | 2 +- net/sctp/sm_sideeffect.c | 2 +- net/sctp/sm_statefuns.c | 2 +- 5 files changed, 7 insertions(+), 7 deletions(-) (limited to 'net/sctp') diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c index aea2a982984d..8a58f42d6d19 100644 --- a/net/sctp/ipv6.c +++ b/net/sctp/ipv6.c @@ -875,7 +875,7 @@ static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp) case AF_INET: if (!__ipv6_only_sock(sctp_opt2sk(sp))) return 1; - /* fallthru */ + fallthrough; default: return 0; } diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c index 577e3bc4ee6f..3fd06a27105d 100644 --- a/net/sctp/outqueue.c +++ b/net/sctp/outqueue.c @@ -912,7 +912,7 @@ static void sctp_outq_flush_ctrl(struct sctp_flush_ctx *ctx) case SCTP_CID_ABORT: if (sctp_test_T_bit(chunk)) ctx->packet->vtag = ctx->asoc->c.my_vtag; - /* fallthru */ + fallthrough; /* The following chunks are "response" chunks, i.e. * they are generated in response to something we @@ -927,7 +927,7 @@ static void sctp_outq_flush_ctrl(struct sctp_flush_ctx *ctx) case SCTP_CID_ECN_CWR: case SCTP_CID_ASCONF_ACK: one_packet = 1; - /* Fall through */ + fallthrough; case SCTP_CID_SACK: case SCTP_CID_HEARTBEAT: @@ -1030,7 +1030,7 @@ static void sctp_outq_flush_data(struct sctp_flush_ctx *ctx, if (!ctx->packet || !ctx->packet->has_cookie_echo) return; - /* fall through */ + fallthrough; case SCTP_STATE_ESTABLISHED: case SCTP_STATE_SHUTDOWN_PENDING: case SCTP_STATE_SHUTDOWN_RECEIVED: diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c index 47910470e532..c11c24524652 100644 --- a/net/sctp/sm_make_chunk.c +++ b/net/sctp/sm_make_chunk.c @@ -2077,7 +2077,7 @@ static enum sctp_ierror sctp_process_unk_param( break; case SCTP_PARAM_ACTION_DISCARD_ERR: retval = SCTP_IERROR_ERROR; - /* Fall through */ + fallthrough; case SCTP_PARAM_ACTION_SKIP_ERR: /* Make an ERROR chunk, preparing enough room for * returning multiple unknown parameters. diff --git a/net/sctp/sm_sideeffect.c b/net/sctp/sm_sideeffect.c index 9f36fe911d08..aa821e71f05e 100644 --- a/net/sctp/sm_sideeffect.c +++ b/net/sctp/sm_sideeffect.c @@ -1516,7 +1516,7 @@ static int sctp_cmd_interpreter(enum sctp_event_type event_type, if (timer_pending(timer)) break; - /* fall through */ + fallthrough; case SCTP_CMD_TIMER_START: timer = &asoc->timers[cmd->obj.to]; diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c index e86620fbd90f..c669f8bd1eab 100644 --- a/net/sctp/sm_statefuns.c +++ b/net/sctp/sm_statefuns.c @@ -4315,7 +4315,7 @@ enum sctp_disposition sctp_sf_eat_auth(struct net *net, sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(err_chunk)); } - /* Fall Through */ + fallthrough; case SCTP_IERROR_AUTH_BAD_KEYID: case SCTP_IERROR_BAD_SIG: return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); -- cgit v1.2.3 From 3106ecb43a05dc3e009779764b9da245a5d082de Mon Sep 17 00:00:00 2001 From: Xin Long Date: Fri, 21 Aug 2020 14:59:38 +0800 Subject: sctp: not disable bh in the whole sctp_get_port_local() With disabling bh in the whole sctp_get_port_local(), when snum == 0 and too many ports have been used, the do-while loop will take the cpu for a long time and cause cpu stuck: [ ] watchdog: BUG: soft lockup - CPU#11 stuck for 22s! [ ] RIP: 0010:native_queued_spin_lock_slowpath+0x4de/0x940 [ ] Call Trace: [ ] _raw_spin_lock+0xc1/0xd0 [ ] sctp_get_port_local+0x527/0x650 [sctp] [ ] sctp_do_bind+0x208/0x5e0 [sctp] [ ] sctp_autobind+0x165/0x1e0 [sctp] [ ] sctp_connect_new_asoc+0x355/0x480 [sctp] [ ] __sctp_connect+0x360/0xb10 [sctp] There's no need to disable bh in the whole function of sctp_get_port_local. So fix this cpu stuck by removing local_bh_disable() called at the beginning, and using spin_lock_bh() instead. The same thing was actually done for inet_csk_get_port() in Commit ea8add2b1903 ("tcp/dccp: better use of ephemeral ports in bind()"). Thanks to Marcelo for pointing the buggy code out. v1->v2: - use cond_resched() to yield cpu to other tasks if needed, as Eric noticed. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Ying Xu Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller --- net/sctp/socket.c | 16 ++++++---------- 1 file changed, 6 insertions(+), 10 deletions(-) (limited to 'net/sctp') diff --git a/net/sctp/socket.c b/net/sctp/socket.c index ec1fba1fbe71..836615f71a7d 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -8060,8 +8060,6 @@ static int sctp_get_port_local(struct sock *sk, union sctp_addr *addr) pr_debug("%s: begins, snum:%d\n", __func__, snum); - local_bh_disable(); - if (snum == 0) { /* Search for an available port. */ int low, high, remaining, index; @@ -8079,20 +8077,21 @@ static int sctp_get_port_local(struct sock *sk, union sctp_addr *addr) continue; index = sctp_phashfn(net, rover); head = &sctp_port_hashtable[index]; - spin_lock(&head->lock); + spin_lock_bh(&head->lock); sctp_for_each_hentry(pp, &head->chain) if ((pp->port == rover) && net_eq(net, pp->net)) goto next; break; next: - spin_unlock(&head->lock); + spin_unlock_bh(&head->lock); + cond_resched(); } while (--remaining > 0); /* Exhausted local port range during search? */ ret = 1; if (remaining <= 0) - goto fail; + return ret; /* OK, here is the one we will use. HEAD (the port * hash table list entry) is non-NULL and we hold it's @@ -8107,7 +8106,7 @@ static int sctp_get_port_local(struct sock *sk, union sctp_addr *addr) * port iterator, pp being NULL. */ head = &sctp_port_hashtable[sctp_phashfn(net, snum)]; - spin_lock(&head->lock); + spin_lock_bh(&head->lock); sctp_for_each_hentry(pp, &head->chain) { if ((pp->port == snum) && net_eq(pp->net, net)) goto pp_found; @@ -8207,10 +8206,7 @@ success: ret = 0; fail_unlock: - spin_unlock(&head->lock); - -fail: - local_bh_enable(); + spin_unlock_bh(&head->lock); return ret; } -- cgit v1.2.3