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137 lines
3.4 KiB
Diff
137 lines
3.4 KiB
Diff
From 0af5d7d021bb899d9c3880415267e178a20fb7a9 Mon Sep 17 00:00:00 2001
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From: Mans Rullgard <mans@mansr.com>
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Date: Thu, 24 Nov 2016 18:46:41 +0000
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Subject: [PATCH] ivshmem-net: fix race in state machine
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(cherry picked from commit 5d663baed6a89d09bae4446f6509f9957c780bc7)
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---
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drivers/net/ivshmem-net.c | 60 ++++++++++++++++++++++++-----------------------
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1 file changed, 31 insertions(+), 29 deletions(-)
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--- a/drivers/net/ivshmem-net.c
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+++ b/drivers/net/ivshmem-net.c
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@@ -36,6 +36,8 @@
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#define IVSHM_NET_STATE_READY 2
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#define IVSHM_NET_STATE_RUN 3
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+#define IVSHM_NET_FLAG_RUN 0
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+
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#define IVSHM_NET_MTU_MIN 256
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#define IVSHM_NET_MTU_MAX 65535
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#define IVSHM_NET_MTU_DEF 16384
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@@ -96,6 +98,8 @@ struct ivshm_net {
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u32 lstate;
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u32 rstate;
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+ unsigned long flags;
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+
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struct workqueue_struct *state_wq;
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struct work_struct state_work;
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@@ -529,12 +533,32 @@ static void ivshm_net_run(struct net_dev
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{
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struct ivshm_net *in = netdev_priv(ndev);
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+ if (in->lstate < IVSHM_NET_STATE_READY)
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+ return;
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+
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+ if (!netif_running(ndev))
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+ return;
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+
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+ if (test_and_set_bit(IVSHM_NET_FLAG_RUN, &in->flags))
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+ return;
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+
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netif_start_queue(ndev);
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napi_enable(&in->napi);
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napi_schedule(&in->napi);
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ivshm_net_set_state(in, IVSHM_NET_STATE_RUN);
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}
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+static void ivshm_net_do_stop(struct net_device *ndev)
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+{
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+ struct ivshm_net *in = netdev_priv(ndev);
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+
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+ if (!test_and_clear_bit(IVSHM_NET_FLAG_RUN, &in->flags))
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+ return;
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+
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+ netif_stop_queue(ndev);
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+ napi_disable(&in->napi);
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+}
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+
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static void ivshm_net_state_change(struct work_struct *work)
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{
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struct ivshm_net *in = container_of(work, struct ivshm_net, state_work);
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@@ -560,21 +584,13 @@ static void ivshm_net_state_change(struc
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break;
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case IVSHM_NET_STATE_READY:
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+ case IVSHM_NET_STATE_RUN:
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if (rstate >= IVSHM_NET_STATE_READY) {
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netif_carrier_on(ndev);
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- if (ndev->flags & IFF_UP)
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- ivshm_net_run(ndev);
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+ ivshm_net_run(ndev);
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} else {
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netif_carrier_off(ndev);
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- ivshm_net_set_state(in, IVSHM_NET_STATE_RESET);
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- }
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- break;
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-
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- case IVSHM_NET_STATE_RUN:
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- if (rstate < IVSHM_NET_STATE_READY) {
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- netif_stop_queue(ndev);
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- napi_disable(&in->napi);
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- netif_carrier_off(ndev);
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+ ivshm_net_do_stop(ndev);
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ivshm_net_set_state(in, IVSHM_NET_STATE_RESET);
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}
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break;
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@@ -584,18 +600,13 @@ static void ivshm_net_state_change(struc
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WRITE_ONCE(in->rstate, rstate);
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}
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-static bool ivshm_net_check_state(struct net_device *ndev)
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+static void ivshm_net_check_state(struct net_device *ndev)
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{
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struct ivshm_net *in = netdev_priv(ndev);
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u32 rstate = readl(&in->ivshm_regs->rstate);
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- if (rstate != READ_ONCE(in->rstate) ||
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- in->lstate != IVSHM_NET_STATE_RUN) {
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+ if (rstate != in->rstate || !test_bit(IVSHM_NET_FLAG_RUN, &in->flags))
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queue_work(in->state_wq, &in->state_work);
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- return false;
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- }
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-
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- return true;
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}
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static irqreturn_t ivshm_net_int(int irq, void *data)
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@@ -617,24 +628,15 @@ static int ivshm_net_open(struct net_dev
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netdev_reset_queue(ndev);
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ndev->operstate = IF_OPER_UP;
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-
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- if (in->lstate == IVSHM_NET_STATE_READY)
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- ivshm_net_run(ndev);
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+ ivshm_net_run(ndev);
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return 0;
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}
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static int ivshm_net_stop(struct net_device *ndev)
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{
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- struct ivshm_net *in = netdev_priv(ndev);
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-
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ndev->operstate = IF_OPER_DOWN;
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-
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- if (in->lstate == IVSHM_NET_STATE_RUN) {
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- napi_disable(&in->napi);
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- netif_stop_queue(ndev);
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- ivshm_net_set_state(in, IVSHM_NET_STATE_READY);
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- }
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+ ivshm_net_do_stop(ndev);
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return 0;
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}
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