From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Eric Dumazet <edumazet@google.com>,
Yuchung Cheng <ycheng@google.com>,
"David S. Miller" <davem@davemloft.net>,
Sasha Levin <alexander.levin@microsoft.com>
Subject: [PATCH 3.18 14/47] tcp: remove poll() flakes with FastOpen
Date: Fri, 23 Mar 2018 10:55:05 +0100 [thread overview]
Message-ID: <20180323094248.739074746@linuxfoundation.org> (raw)
In-Reply-To: <20180323094248.117679641@linuxfoundation.org>
3.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Dumazet <edumazet@google.com>
[ Upstream commit 0f9fa831aecfc297b7b45d4f046759bcefcf87f0 ]
When using TCP FastOpen for an active session, we send one wakeup event
from tcp_finish_connect(), right before the data eventually contained in
the received SYNACK is queued to sk->sk_receive_queue.
This means that depending on machine load or luck, poll() users
might receive POLLOUT events instead of POLLIN|POLLOUT
To fix this, we need to move the call to sk->sk_state_change()
after the (optional) call to tcp_rcv_fastopen_synack()
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/ipv4/tcp_input.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -5322,10 +5322,6 @@ void tcp_finish_connect(struct sock *sk,
else
tp->pred_flags = 0;
- if (!sock_flag(sk, SOCK_DEAD)) {
- sk->sk_state_change(sk);
- sk_wake_async(sk, SOCK_WAKE_IO, POLL_OUT);
- }
}
static bool tcp_rcv_fastopen_synack(struct sock *sk, struct sk_buff *synack,
@@ -5380,6 +5376,7 @@ static int tcp_rcv_synsent_state_process
struct tcp_sock *tp = tcp_sk(sk);
struct tcp_fastopen_cookie foc = { .len = -1 };
int saved_clamp = tp->rx_opt.mss_clamp;
+ bool fastopen_fail;
tcp_parse_options(skb, &tp->rx_opt, 0, &foc);
if (tp->rx_opt.saw_tstamp && tp->rx_opt.rcv_tsecr)
@@ -5482,10 +5479,15 @@ static int tcp_rcv_synsent_state_process
tcp_finish_connect(sk, skb);
- if ((tp->syn_fastopen || tp->syn_data) &&
- tcp_rcv_fastopen_synack(sk, skb, &foc))
- return -1;
+ fastopen_fail = (tp->syn_fastopen || tp->syn_data) &&
+ tcp_rcv_fastopen_synack(sk, skb, &foc);
+ if (!sock_flag(sk, SOCK_DEAD)) {
+ sk->sk_state_change(sk);
+ sk_wake_async(sk, SOCK_WAKE_IO, POLL_OUT);
+ }
+ if (fastopen_fail)
+ return -1;
if (sk->sk_write_pending ||
icsk->icsk_accept_queue.rskq_defer_accept ||
icsk->icsk_ack.pingpong) {
next prev parent reply other threads:[~2018-03-23 9:55 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-23 9:54 [PATCH 3.18 00/47] 3.18.102-stable review Greg Kroah-Hartman
2018-03-23 9:54 ` [PATCH 3.18 01/47] platform/x86: asus-nb-wmi: Add wapf4 quirk for the X302UA Greg Kroah-Hartman
2018-03-23 9:54 ` [PATCH 3.18 02/47] x86: i8259: export legacy_pic symbol Greg Kroah-Hartman
2018-03-23 9:54 ` [PATCH 3.18 03/47] Input: ar1021_i2c - fix too long name in drivers device table Greg Kroah-Hartman
2018-03-23 9:54 ` [PATCH 3.18 04/47] ACPI/processor: Replace racy task affinity logic Greg Kroah-Hartman
2018-03-23 9:54 ` [PATCH 3.18 05/47] cpufreq/sh: " Greg Kroah-Hartman
2018-03-23 9:54 ` [PATCH 3.18 06/47] genirq: Use irqd_get_trigger_type to compare the trigger type for shared IRQs Greg Kroah-Hartman
2018-03-23 9:54 ` [PATCH 3.18 07/47] i2c: i2c-scmi: add a MS HID Greg Kroah-Hartman
2018-03-23 9:54 ` [PATCH 3.18 08/47] net: ipv6: send unsolicited NA on admin up Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 09/47] [media] media/dvb-core: Race condition when writing to CAM Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 10/47] spi: dw: Disable clock after unregistering the host Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 11/47] ath: Fix updating radar flags for coutry code India Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 12/47] scsi: virtio_scsi: Always try to read VPD pages Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 13/47] KVM: PPC: Book3S PR: Exit KVM on failed mapping Greg Kroah-Hartman
2018-03-23 9:55 ` Greg Kroah-Hartman [this message]
2018-03-23 9:55 ` [PATCH 3.18 15/47] e1000e: fix timing for 82579 Gigabit Ethernet controller Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 16/47] ALSA: hda - Fix headset microphone detection for ASUS N551 and N751 Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 17/47] IB/ipoib: Update broadcast object if PKey value was changed in index 0 Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 18/47] HSI: ssi_protocol: double free in ssip_pn_xmit() Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 19/47] Fix driver usage of 128B WQEs when WQ_CREATE is V1 Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 20/47] mmc: host: omap_hsmmc: checking for NULL instead of IS_ERR() Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 21/47] wan: pc300too: abort path on failure Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 22/47] qlcnic: fix unchecked return value Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 23/47] scsi: mac_esp: Replace bogus memory barrier with spinlock Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 24/47] rndis_wlan: add return value validation Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 25/47] Btrfs: send, fix file hole not being preserved due to inline extent Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 26/47] mac80211: dont parse encrypted management frames in ieee80211_frame_acked Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 27/47] mfd: palmas: Reset the POWERHOLD mux during power off Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 28/47] ARM: DRA7: clockdomain: Change the CLKTRCTRL of CM_PCIE_CLKSTCTRL to SW_WKUP Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 29/47] ipmi/watchdog: fix wdog hang on panic waiting for ipmi response Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 30/47] bnx2x: Align RX buffers Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 31/47] power: supply: pda_power: move from timer to delayed_work Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 32/47] md/raid10: skip spare disk as first disk Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 33/47] ia64: fix module loading for gcc-5.4 Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 34/47] video: fbdev: udlfb: Fix buffer on stack Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 35/47] sm501fb: dont return zero on failure path in sm501fb_start() Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 36/47] cifs: small underflow in cnvrtDosUnixTm() Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 37/47] drm/msm: fix leak in failed get_pages Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 38/47] media: bt8xx: Fix err bt878_probe() Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 39/47] media: [RESEND] media: dvb-frontends: Add delay to Si2168 restart Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 40/47] mmc: avoid removing non-removable hosts during suspend Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 41/47] IB/ipoib: Avoid memory leak if the SA returns a different DGID Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 42/47] RDMA/cma: Use correct size when writing netlink stats Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 43/47] vgacon: Set VGA struct resource types Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 44/47] drm/omap: DMM: Check for DMM readiness after successful transaction commit Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 45/47] pinctrl: Really force states during suspend/resume Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 46/47] clk: si5351: Rename internal plls to avoid name collisions Greg Kroah-Hartman
2018-03-23 9:55 ` [PATCH 3.18 47/47] RDMA/ucma: Fix access to non-initialized CM_ID object Greg Kroah-Hartman
2018-03-23 14:00 ` [PATCH 3.18 00/47] 3.18.102-stable review kernelci.org bot
2018-03-23 20:43 ` Shuah Khan
2018-03-24 7:46 ` Greg Kroah-Hartman
2018-03-24 0:07 ` Guenter Roeck
2018-03-24 9:40 ` Harsh Shandilya
2018-03-24 10:05 ` Greg Kroah-Hartman
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