linux-kernel - [PATCH 5.4 37/43] net: lantiq: Disable IRQs only if NAPI gets scheduled

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 25 Sep 2020 14:48:49 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Hauke Mehrtens <hauke@...ke-m.de>,
        "David S. Miller" <davem@...emloft.net>
Subject: [PATCH 5.4 37/43] net: lantiq: Disable IRQs only if NAPI gets scheduled

From: Hauke Mehrtens <hauke@...ke-m.de>

[ Upstream commit 9423361da52356cb68642db5b2729b6b85aad330 ]

The napi_schedule() call will only schedule the NAPI if it is not
already running. To make sure that we do not deactivate interrupts
without scheduling NAPI only deactivate the interrupts in case NAPI also
gets scheduled.

Signed-off-by: Hauke Mehrtens <hauke@...ke-m.de>
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 drivers/net/ethernet/lantiq_xrx200.c |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

--- a/drivers/net/ethernet/lantiq_xrx200.c
+++ b/drivers/net/ethernet/lantiq_xrx200.c
@@ -344,10 +344,12 @@ static irqreturn_t xrx200_dma_irq(int ir
 {
 	struct xrx200_chan *ch = ptr;
 
-	ltq_dma_disable_irq(&ch->dma);
-	ltq_dma_ack_irq(&ch->dma);
+	if (napi_schedule_prep(&ch->napi)) {
+		__napi_schedule(&ch->napi);
+		ltq_dma_disable_irq(&ch->dma);
+	}
 
-	napi_schedule(&ch->napi);
+	ltq_dma_ack_irq(&ch->dma);
 
 	return IRQ_HANDLED;
 }