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Commit 29d09c2b authored by Harout Hedeshian's avatar Harout Hedeshian Committed by Subash Abhinov Kasiviswanathan
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msm_bam_rmnet: Check for sufficient headroom 



Check for sufficient headroom before attempting transmit. Prevent
crash when skb_push() with insufficient headroom. Added module parameter
to track number of times packet expansion required.

Change-Id: I09126f885b38a47a3ebc2556b5458343acd19d03
Signed-off-by: default avatarHarout Hedeshian <harouth@codeaurora.org>
parent 4de58433

drivers/net/ethernet/msm/msm_rmnet_bam.c

+26 −0
Original line number Diff line number Diff line
@@ -42,6 +42,11 @@ static int msm_rmnet_bam_debug_mask; 
module_param_named(debug_enable, msm_rmnet_bam_debug_mask,

			int, S_IRUGO | S_IWUSR | S_IWGRP);



static unsigned long int msm_rmnet_bam_headroom_check_failure;

module_param(msm_rmnet_bam_headroom_check_failure, ulong, S_IRUGO);

MODULE_PARM_DESC(msm_rmnet_bam_headroom_check_failure,

		 "Number of packets with insufficient headroom");



#define DEBUG_MASK_LVL0 (1U << 0)

#define DEBUG_MASK_LVL1 (1U << 1)

#define DEBUG_MASK_LVL2 (1U << 2)
@@ -287,6 +292,23 @@ static void bam_recv_notify(void *dev, struct sk_buff *skb) 
			((struct net_device *)dev)->name, __func__);

}



static struct sk_buff *_rmnet_add_headroom(struct sk_buff **skb,

					   struct net_device *dev)

{

	struct sk_buff *skbn;



	if (skb_headroom(*skb) < dev->needed_headroom) {

		msm_rmnet_bam_headroom_check_failure++;

		skbn = skb_realloc_headroom(*skb, dev->needed_headroom);

		kfree_skb(*skb);

		*skb = skbn;

	} else {

		skbn = *skb;

	}



	return skbn;

}



static int _rmnet_xmit(struct sk_buff *skb, struct net_device *dev)

{

	struct rmnet_private *p = netdev_priv(dev);
@@ -295,6 +317,10 @@ static int _rmnet_xmit(struct sk_buff *skb, struct net_device *dev) 
	u32 opmode;

	unsigned long flags;



	if (unlikely(!_rmnet_add_headroom(&skb, dev))) {

		dev->stats.tx_dropped++;

		return NETDEV_TX_OK;

	}

	/* For QoS mode, prepend QMI header and assign flow ID from skb->mark */

	spin_lock_irqsave(&p->lock, flags);

	opmode = p->operation_mode;