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Date:   Mon, 29 May 2023 06:30:19 -0700
From:   Shradha Gupta <shradhagupta@linux.microsoft.com>
To:     Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc:     linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org,
        netdev@vger.kernel.org, Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        "K. Y. Srinivasan" <kys@microsoft.com>,
        Haiyang Zhang <haiyangz@microsoft.com>,
        Wei Liu <wei.liu@kernel.org>, Dexuan Cui <decui@microsoft.com>,
        Long Li <longli@microsoft.com>,
        Michael Kelley <mikelley@microsoft.com>,
        "David S. Miller" <davem@davemloft.net>,
        Steen Hegelund <steen.hegelund@microchip.com>,
        Simon Horman <simon.horman@corigine.com>
Subject: Re: [PATCH v3] hv_netvsc: Allocate rx indirection table size
 dynamically
Message-ID: <20230529133019.GB21447@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net>
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 <92bc6f3e-4463-e0fe-5cab-54c6c5eecd3f@wanadoo.fr>
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Thanks for the comment Christophe.
On Mon, May 29, 2023 at 02:49:15PM +0200, Christophe JAILLET wrote:
> Le 26/05/2023 ?? 08:02, Shradha Gupta a ??crit??:
> >Allocate the size of rx indirection table dynamically in netvsc
> >from the value of size provided by OID_GEN_RECEIVE_SCALE_CAPABILITIES
> >query instead of using a constant value of ITAB_NUM.
> >
> >Signed-off-by: Shradha Gupta <shradhagupta@linux.microsoft.com>
> >Tested-on: Ubuntu22 (azure VM, SKU size: Standard_F72s_v2)
> >Testcases:
> >1. ethtool -x eth0 output
> >2. LISA testcase:PERF-NETWORK-TCP-THROUGHPUT-MULTICONNECTION-NTTTCP-Synthetic
> >3. LISA testcase:PERF-NETWORK-TCP-THROUGHPUT-MULTICONNECTION-NTTTCP-SRIOV
> >
> >---
> 
> [...]
> 
> >@@ -1596,11 +1608,18 @@ void rndis_filter_device_remove(struct hv_device *dev,
> >  				struct netvsc_device *net_dev)
> >  {
> >  	struct rndis_device *rndis_dev = net_dev->extension;
> >+	struct net_device *net = hv_get_drvdata(dev);
> >+	struct net_device_context *ndc = netdev_priv(net);
> >  	/* Halt and release the rndis device */
> >  	rndis_filter_halt_device(net_dev, rndis_dev);
> >  	netvsc_device_remove(dev);
> >+
> >+	ndc->rx_table_sz = 0;
> >+	kfree(ndc->rx_table);
> >+	ndc->rx_table = NULL;
> >+
> 
> Nit: useless empty NL
This is to prevent any potential double free, or accessing freed memory, etc.
As requested by Haiyang in v2 patch
> 
> >  }
> >  int rndis_filter_open(struct netvsc_device *nvdev)