From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vlad Yasevich Subject: Re: [PATCH] sctp: fix a BUG_ON on triggered by setting max_autoclose to Date: Tue, 03 Dec 2013 11:09:38 -0500 Message-ID: <529E0242.6020008@gmail.com> References: <529DADE5.4040701@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, linux-sctp@vger.kernel.org To: Wang Weidong , Neil Horman , David Miller Return-path: Received: from mail-yh0-f47.google.com ([209.85.213.47]:38367 "EHLO mail-yh0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753079Ab3LCQJm (ORCPT ); Tue, 3 Dec 2013 11:09:42 -0500 In-Reply-To: <529DADE5.4040701@huawei.com> Sender: netdev-owner@vger.kernel.org List-ID: On 12/03/2013 05:09 AM, Wang Weidong wrote: > since 2692ba61, add the max_autoclose to sysctl. when I setted the > max_autoclose to 0. Just do the test_autoclose, it will trigger that: > > [ 608.056238] ------------[ cut here ]------------ > [ 608.056244] kernel BUG at /home/wwd/work/linux/net/sctp/sm_sideeffect.c:1488! > [ 608.056250] invalid opcode: 0000 [#1] SMP > [ 608.056254] Modules linked in: md5 sctp(O) crc32c libcrc32c edd fuse loop dm_mod ipv6 8139too sg 8139cp mii i2c_piix4 i2c_core virtio_balloon intel_agp virtio_pci virtio_ring sr_mod cdrom rtc_cmos joydev hid_generic intel_gtt virtio floppy pcspkr button ext3 jbd mbcache usbhid hid uhci_hcd ehci_hcd usbcore sd_mod usb_common crc_t10dif crct10dif_common processor thermal_sys hwmon scsi_dh_emc scsi_dh_alua scsi_dh_hp_sw scsi_dh_rdac scsi_dh ata_generic ata_piix libata scsi_mod [last unloaded: sctp] > [ 608.056310] CPU: 5 PID: 4517 Comm: test_autoclose Tainted: G R O 3.13.0-rc1-0.27-default+ #2 > [ 608.056315] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007 > [ 608.056319] task: ffff8800372f5590 ti: ffff8800db882000 task.ti: ffff8800db882000 > [ 608.056323] RIP: 0010:[] [] sctp_cmd_interpreter+0x1010/0x1070 [sctp] > [ 608.056339] RSP: 0018:ffff880116f43928 EFLAGS: 00010246 > [ 608.056343] RAX: 0000000000000009 RBX: ffff880116f43ab8 RCX: 0000000000000009 > [ 608.056349] RDX: 0000000000000003 RSI: 0000000000000000 RDI: ffff880116f43a88 > [ 608.056353] RBP: ffff880116f439d8 R08: 0000000000002029 R09: 0000000000000001 > [ 608.056357] R10: 0000000000000000 R11: 0000000000000005 R12: ffff8800db7c9150 > [ 608.056361] R13: 0000000000000000 R14: ffff8800db7c9000 R15: 0000000000000001 > [ 608.056365] FS: 00007f942d71c700(0000) GS:ffff880116f40000(0000) knlGS:0000000000000000 > [ 608.056370] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b > [ 608.056373] CR2: 00007f942d324d90 CR3: 00000000db094000 CR4: 00000000000006e0 > [ 608.056382] Stack: > [ 608.056384] 0000000000000018 ffff880116f43988 ffff8800da569600 000000010000000a > [ 608.056391] ffff880037265e40 0000000016f43988 ffff880116f439e8 0000000000000000 > [ 608.056397] ffffffffa0365101 0000000000000000 ffff880116f43a28 ffffffff812b7739 > [ 608.056403] Call Trace: > [ 608.056406] > [ 608.056409] > [ 608.056421] [] ? __dynamic_pr_debug+0x69/0x80 > [ 608.056432] [] ? trace_hardirqs_off+0xd/0x10 > [ 608.056442] [] ? _raw_spin_unlock_irqrestore+0x58/0x60 > [ 608.056451] [] sctp_side_effects+0x36/0x130 [sctp] > [ 608.056459] [] sctp_do_sm+0xe7/0x210 [sctp] > [ 608.056470] [] ? sctp_rcv+0x780/0x780 [sctp] > [ 608.056479] [] sctp_endpoint_bh_rcv+0x10f/0x220 [sctp] > [ 608.056489] [] sctp_inq_push+0x41/0x60 [sctp] > [ 608.056498] [] sctp_rcv+0x6d5/0x780 [sctp] > [ 608.056508] [] ? sctp_csum_combine+0x10/0x10 [sctp] > [ 608.056518] [] ? sctp_v4_err+0x240/0x240 [sctp] > [ 608.056528] [] ip_local_deliver_finish+0xf4/0x270 > [ 608.056533] [] ? ip_local_deliver_finish+0x40/0x270 > [ 608.056538] [] ip_local_deliver+0x80/0x90 > [ 608.056543] [] ip_rcv_finish+0x1b3/0x600 > [ 608.056547] [] ? ip_local_deliver_finish+0x270/0x270 > [ 608.056552] [] NF_HOOK+0x2f/0x70 > [ 608.056565] [] ? __netif_receive_skb_core+0x113/0x7a0 > [ 608.056570] [] ip_rcv+0x2d5/0x3b0 > [ 608.056575] [] __netif_receive_skb_core+0x6ff/0x7a0 > [ 608.056580] [] ? __netif_receive_skb_core+0x113/0x7a0 > [ 608.056585] [] ? process_backlog+0x1a8/0x1c0 > [ 608.056590] [] __netif_receive_skb+0x2b/0x80 > [ 608.056595] [] process_backlog+0xb8/0x1c0 > [ 608.056600] [] net_rx_action+0x11c/0x240 > [ 608.056607] [] __do_softirq+0x118/0x290 > [ 608.056615] [] do_softirq_own_stack+0x1c/0x30 > [ 608.056618] > [ 608.056620] > [ 608.056623] [] do_softirq+0x65/0x70 > [ 608.056629] [] ? release_sock+0x8c/0xa0 > [ 608.056635] [] local_bh_enable_ip+0xb3/0xc0 > [ 608.056640] [] _raw_spin_unlock_bh+0x2f/0x40 > [ 608.056645] [] release_sock+0x8c/0xa0 > [ 608.056654] [] sctp_sendmsg+0x3a8/0xcc0 [sctp] > [ 608.056661] [] ? number+0x33a/0x360 > [ 608.056667] [] inet_sendmsg+0x9c/0x100 > [ 608.056672] [] ? inet_recvmsg+0x110/0x110 > [ 608.056679] [] sock_sendmsg+0x97/0xc0 > [ 608.056690] [] ? might_fault+0x3e/0x90 > [ 608.056695] [] ? might_fault+0x3e/0x90 > [ 608.056700] [] ? verify_iovec+0x53/0x100 > [ 608.056705] [] ___sys_sendmsg+0x416/0x420 > [ 608.056710] [] ? __do_fault+0x216/0x510 > [ 608.056715] [] ? __do_page_fault+0x2b4/0x4a0 > [ 608.056720] [] ? up_read+0x1e/0x40 > [ 608.056724] [] ? __do_page_fault+0x2b4/0x4a0 > [ 608.056729] [] ? release_sock+0x8c/0xa0 > [ 608.056733] [] ? release_sock+0x8c/0xa0 > [ 608.056741] [] ? trace_hardirqs_on+0xd/0x10 > [ 608.056746] [] ? local_bh_enable_ip+0x65/0xc0 > [ 608.056751] [] __sys_sendmsg+0x44/0x80 > [ 608.056756] [] SyS_sendmsg+0x14/0x20 > [ 608.056761] [] system_call_fastpath+0x16/0x1b > ------------------------------------- > > The reason is: In test_autoclose set the autoclose to 5 not 0(default). So when > we init the association, the (sctp_sock) sp->autoclose is not 0 while asoc's > timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] is 0. > So when we process the COOKIE_ACK, the sctp_sf_do_5_1E_ca will be called, that > will do that: > if (asoc->autoclose) //asoc->autoclose is equal sp->autoclose > sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, > SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); this looks like a bug in how the timeout is being set. The timeout should be based on the association value, not some sysctl value. The typical socket option values go like this: socket value = starts at sysctl, changed by user. assoc value = starts at socket value, may be changed by user. any timer = starts at assoc value. this seems to be broken for autoclose. > then the sctp_do_sm will goto the SCTP_CMD_TIMER_START where place a BUG_ON. > So When we do test_autoclose will trigger the BUG_ON. > And when the sp->autoclose is 0, it will not happen. > > the timeout is zero only when the sp->autoclose is 0. While the sp->autoclose should > consistent between setsockopt() and getsockopt() calls. > so I make the max_autoclose min value to 1. > > Signed-off-by: Wang Weidong > --- > net/sctp/sysctl.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c > index 46832d3..8b619d6 100644 > --- a/net/sctp/sysctl.c > +++ b/net/sctp/sysctl.c > @@ -47,7 +47,7 @@ static int sack_timer_min = 1; > static int sack_timer_max = 500; > static int addr_scope_max = 3; /* check sctp_scope_policy_t in include/net/sctp/constants.h for max entries */ > static int rwnd_scale_max = 16; > -static unsigned long max_autoclose_min = 0; > +static unsigned long max_autoclose_min = 1; > static unsigned long max_autoclose_max = > (MAX_SCHEDULE_TIMEOUT / HZ > UINT_MAX) > ? UINT_MAX : MAX_SCHEDULE_TIMEOUT / HZ; > allowing autoclose_min = 0 might be useful to disable autoclose globally. This is not a fix, but a bandaid. -vlad