Commit 95817dd5 authored Jun 17, 2019 by Subash Abhinov Kasiviswanathan

net: qualcomm: rmnet: Add headroom for all skbs queued to stack



Packets in some path may have some header insertion required which
is not supported if there is not enough headroom.

Fixes the following splat-

[ 254.966133] skbuff: skb_under_panic: text:ffffff9a73ed5e58 len:103
put:14 head:ffffffef13451a00 data:ffffffef134519fa tail:0x61 end:0x80
dev:wlan0
[ 254.967224] kernel BUG at net/core/skbuff.c:104!
[ 254.967429] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
[ 254.967858] pc : skb_panic+0x48/0x50
[ 254.967883] lr : skb_panic+0x48/0x50
[ 254.968885] Call trace:
[ 254.968901] skb_panic+0x48/0x50
[ 254.968913] skb_under_panic+0x14/0x18
[ 254.968924] skb_under_panic+0x0/0x18
[ 254.968941] eth_header+0x30/0xc8
[ 254.968959] neigh_resolve_output+0x134/0x188
[ 254.968978] ip6_finish_output2+0x464/0x658
[ 254.968989] ip6_finish_output+0x190/0x210
[ 254.968999] ip6_output+0xc0/0x1a8
[ 254.969018] ip6_local_out+0xe8/0x128
[ 254.969031] nf_dup_ipv6+0x220/0x230
[ 254.969049] tee_tg6+0x38/0x48
[ 254.969062] ip6t_do_table+0x2e4/0x648
[ 254.969077] ip6table_mangle_hook+0x148/0x180
[ 254.969091] nf_hook_slow+0x48/0xd8
[ 254.969101] ipv6_rcv+0x384/0x548
[ 254.969117] __netif_receive_skb_core+0x9c0/0xb80
[ 254.969129] process_backlog+0x14c/0x278
[ 254.969140] net_rx_action+0x114/0x470
[ 254.969159] __do_softirq+0x1f8/0x3ac
[ 254.969176] irq_exit+0xd0/0xe0
[ 254.969191] handle_IPI+0x188/0x2a0
[ 254.969201] gic_handle_irq+0x130/0x1c0
[ 254.969213] el1_irq+0xb0/0x124
[ 254.969231] lpm_cpuidle_enter+0x4b0/0x4f8
[ 254.969243] cpuidle_enter_state+0x1cc/0x350
[ 254.969253] cpuidle_enter+0x18/0x20
[ 254.969268] do_idle+0x174/0x268
[ 254.969279] cpu_startup_entry+0x20/0x28
[ 254.969290] secondary_start_kernel+0x12c/0x138

CRs-fixed: 2469907
Change-Id: Id4c3f0092151b84593beccb4bae24495ae9f83c0
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>

parent ebfbb23f

drivers/net/ethernet/qualcomm/rmnet/rmnet_descriptor.c

+7 −2

Original line number	Diff line number	Diff line
		@@ -409,10 +409,12 @@ static struct sk_buff rmnet_alloc_skb(struct rmnet_frag_descriptor frag_desc,
		if (frag_desc->hdrs_valid) {
		u16 hdr_len = frag_desc->ip_len + frag_desc->trans_len;

		head_skb = alloc_skb(hdr_len, GFP_ATOMIC);
		head_skb = alloc_skb(hdr_len + RMNET_MAP_DEAGGR_HEADROOM,
		GFP_ATOMIC);
		if (!head_skb)
		return NULL;

		skb_reserve(head_skb, RMNET_MAP_DEAGGR_HEADROOM);
		skb_put_data(head_skb, frag_desc->hdr_ptr, hdr_len);
		skb_reset_network_header(head_skb);
		if (frag_desc->trans_len)
		@@ -431,9 +433,12 @@ static struct sk_buff rmnet_alloc_skb(struct rmnet_frag_descriptor frag_desc,
		/* Allocate enough space to avoid penalties in the stack
		* from __pskb_pull_tail()
		*/
		head_skb = alloc_skb(256, GFP_ATOMIC);
		head_skb = alloc_skb(256 + RMNET_MAP_DEAGGR_HEADROOM,
		GFP_ATOMIC);
		if (!head_skb)
		return NULL;

		skb_reserve(head_skb, RMNET_MAP_DEAGGR_HEADROOM);
		}

		/* Add main fragment */