From 0486a063b1ffce4f37ef80970689c64bf7b99e98 Mon Sep 17 00:00:00 2001 From: Ivan Vecera Date: Mon, 1 Sep 2014 14:21:57 +0200 Subject: [PATCH] tg3: prevent ifup/ifdown during PCI error recovery The patch fixes race conditions between PCI error recovery callbacks and potential ifup/ifdown. First, if ifup (tg3_open) is called between tg3_io_error_detected() and tg3_io_resume() then tp->timer is armed twice before expiry. Once during tg3_open() and again during tg3_io_resume(). This results in BUG at kernel/time/timer.c:945. Second, if ifdown (tg3_close) is called between tg3_io_error_detected() and tg3_io_resume() then tg3_napi_disable() is called twice without a tg3_napi_enable between. Once during tg3_io_error_detected() and again during tg3_close(). The tg3_io_resume() then hangs on rtnl_lock(). v2: Added logging messages per Prashant's request Cc: Prashant Sreedharan Cc: Michael Chan Signed-off-by: Ivan Vecera Acked-by: Prashant Sreedharan Signed-off-by: David S. Miller --- drivers/net/ethernet/broadcom/tg3.c | 16 ++++++++++++++++ drivers/net/ethernet/broadcom/tg3.h | 1 + 2 files changed, 17 insertions(+) diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c index 3ac5d23454a8..cb77ae93d89a 100644 --- a/drivers/net/ethernet/broadcom/tg3.c +++ b/drivers/net/ethernet/broadcom/tg3.c @@ -11617,6 +11617,12 @@ static int tg3_open(struct net_device *dev) struct tg3 *tp = netdev_priv(dev); int err; + if (tp->pcierr_recovery) { + netdev_err(dev, "Failed to open device. PCI error recovery " + "in progress\n"); + return -EAGAIN; + } + if (tp->fw_needed) { err = tg3_request_firmware(tp); if (tg3_asic_rev(tp) == ASIC_REV_57766) { @@ -11674,6 +11680,12 @@ static int tg3_close(struct net_device *dev) { struct tg3 *tp = netdev_priv(dev); + if (tp->pcierr_recovery) { + netdev_err(dev, "Failed to close device. PCI error recovery " + "in progress\n"); + return -EAGAIN; + } + tg3_ptp_fini(tp); tg3_stop(tp); @@ -17561,6 +17573,7 @@ static int tg3_init_one(struct pci_dev *pdev, tp->rx_mode = TG3_DEF_RX_MODE; tp->tx_mode = TG3_DEF_TX_MODE; tp->irq_sync = 1; + tp->pcierr_recovery = false; if (tg3_debug > 0) tp->msg_enable = tg3_debug; @@ -18071,6 +18084,8 @@ static pci_ers_result_t tg3_io_error_detected(struct pci_dev *pdev, rtnl_lock(); + tp->pcierr_recovery = true; + /* We probably don't have netdev yet */ if (!netdev || !netif_running(netdev)) goto done; @@ -18195,6 +18210,7 @@ static void tg3_io_resume(struct pci_dev *pdev) tg3_phy_start(tp); done: + tp->pcierr_recovery = false; rtnl_unlock(); } diff --git a/drivers/net/ethernet/broadcom/tg3.h b/drivers/net/ethernet/broadcom/tg3.h index 461accaf0aa4..31c9f8295953 100644 --- a/drivers/net/ethernet/broadcom/tg3.h +++ b/drivers/net/ethernet/broadcom/tg3.h @@ -3407,6 +3407,7 @@ struct tg3 { struct device *hwmon_dev; bool link_up; + bool pcierr_recovery; }; /* Accessor macros for chip and asic attributes