rmnet_shs: Fix CFI violation in packet assignment

This fixes the following CFI violation when the rmnet_shs module is
loaded:

CFI failure (target: [<ffffff9cddd1e27c>] rmnet_shs_assign+0x0/0x9d0):
------------[ cut here ]------------
WARNING: CPU: 1 PID: 0 at rmnet_deliver_skb+0x224/0x24c
CPU: 1 PID: 0 Comm: swapper/1 Tainted: G S      W       4.14.186 #1
Hardware name: Qualcomm Technologies, Inc. SM8150 V2 PM8150 MTP 18865 19863 14 15 (DT)
task: 0000000098c067f6 task.stack: 00000000289c42de
pc : rmnet_deliver_skb+0x224/0x24c
lr : rmnet_deliver_skb+0x224/0x24c
sp : ffffff801000bc10 pstate : 60400145
x29: ffffff801000bc10 x28: ffffff9cdc68e798
x27: ffffffe5ed28e090 x26: 0000000000000000
x25: 0000000000000000 x24: ffffffe585b41ca8
x23: 0000000000000001 x22: ffffff9cddd1e27c
x21: ffffffe5f40fd100 x20: ffffffe5dfb95000
x19: ffffffe4eff9d500 x18: 0000000000000002
x17: 000000000000009c x16: 000000000000009c
x15: 0000000000000068 x14: 0000000000000082
x13: ffffff9cdefaec08 x12: 0000000000000004
x11: 00000000ffffffff x10: ffffffe5f5200000
x9 : 99d99e2e2d2e1900 x8 : 99d99e2e2d2e1900
x7 : 0000000000000000 x6 : ffffffe5f5209fc2
x5 : 0000000000000000 x4 : 0000000000000000
x3 : 0000000000003a29 x2 : 0000000000000001
x1 : 0000000000000000 x0 : 0000000000000046
\x0aPC: 0xffffff9cdd12b3fc:
b3fc  a9424ff4 a94157f6 a8c37bfd d65f03c0 91246100 aa1303e1 9431af1a a9424ff4
b41c  a94157f6 a8c37bfd d65f03c0 900091e0 91188000 aa1603e1 aa1603e2 97d8aba3
b43c  d4210000 17ffff9e aa1503e0 97d9478c 17ffffa5 aa1503e0 aa0803f6 97d94788
b45c  aa1603e8 17ffffac d10103ff a9017bfd a90257f6 a9034ff4 910043fd aa0003f3
\x0aLR: 0xffffff9cdd12b3fc:
b3fc  a9424ff4 a94157f6 a8c37bfd d65f03c0 91246100 aa1303e1 9431af1a a9424ff4
b41c  a94157f6 a8c37bfd d65f03c0 900091e0 91188000 aa1603e1 aa1603e2 97d8aba3
b43c  d4210000 17ffff9e aa1503e0 97d9478c 17ffffa5 aa1503e0 aa0803f6 97d94788
b45c  aa1603e8 17ffffac d10103ff a9017bfd a90257f6 a9034ff4 910043fd aa0003f3
\x0aSP: 0xffffff801000bbd0:
bbd0  dd12b43c ffffff9c 60400145 00000000 1000bbb8 ffffff80 dd12b2b4 ffffff9c
bbf0  ffffffff 0000007f 2d2e1900 99d99e2e 1000bc10 ffffff80 dd12b43c ffffff9c
bc10  1000bc40 ffffff80 ddd18d48 ffffff9c 00000040 00000000 ddd18338 ffffff9c
bc30  eff9d500 ffffffe4 85b41c18 ffffffe5 1000bc50 ffffff80 ddd1a390 ffffff9c

Call trace:
rmnet_deliver_skb+0x224/0x24c
rmnet_perf_core_send_skb+0x138/0x140
rmnet_perf_opt_flush_single_flow_node+0x624/0x668
rmnet_perf_core_deaggregate+0x194/0x2c4
rmnet_rx_handler+0x17c/0x270
__netif_receive_skb_core+0x50c/0xba0
process_backlog+0x1e4/0x3d0
net_rx_action+0x134/0x4f4
__do_softirq+0x16c/0x344
irq_exit+0x16c/0x178
handle_IPI+0x220/0x2e0
gic_handle_irq.16379+0xa8/0x180
el1_irq+0xb0/0x124
lpm_cpuidle_enter+0x33c/0x358
cpuidle_enter_state+0x220/0x400
do_idle+0x430/0x5f0
cpu_startup_entry+0x74/0x78
__cpu_disable+0x0/0xf0
---[ end trace 6e7b287874dec53f ]---

Reported-by: Adam W. Willis <[email protected]>
Signed-off-by: Danny Lin <[email protected]>
Signed-off-by: Adam W. Willis <[email protected]>
Signed-off-by: Carlos Ayrton Lopez Arroyo <[email protected]>

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

@@ -88,21 +88,21 @@ void rmnet_set_skb_proto(struct sk_buff *skb)
 EXPORT_SYMBOL(rmnet_set_skb_proto);
 
 /* Shs hook handler */
-int (*rmnet_shs_skb_entry)(struct sk_buff *skb,
-			   struct rmnet_port *port) __rcu __read_mostly;
+void (*rmnet_shs_skb_entry)(struct sk_buff *skb,
+			    struct rmnet_port *port) __rcu __read_mostly;
 EXPORT_SYMBOL(rmnet_shs_skb_entry);
 
 /* Shs hook handler for work queue*/
-int (*rmnet_shs_skb_entry_wq)(struct sk_buff *skb,
-			      struct rmnet_port *port) __rcu __read_mostly;
+void (*rmnet_shs_skb_entry_wq)(struct sk_buff *skb,
+			       struct rmnet_port *port) __rcu __read_mostly;
 EXPORT_SYMBOL(rmnet_shs_skb_entry_wq);
 
 /* Generic handler */
 
 void
 rmnet_deliver_skb(struct sk_buff *skb, struct rmnet_port *port)
 {
-	int (*rmnet_shs_stamp)(struct sk_buff *skb, struct rmnet_port *port);
+	void (*rmnet_shs_stamp)(struct sk_buff *skb, struct rmnet_port *port);
 	struct rmnet_priv *priv = netdev_priv(skb->dev);
 
 	trace_rmnet_low(RMNET_MODULE, RMNET_DLVR_SKB, 0xDEF, 0xDEF,
@@ -147,7 +147,7 @@ void
 rmnet_deliver_skb_wq(struct sk_buff *skb, struct rmnet_port *port,
 		     enum rmnet_packet_context ctx)
 {
-	int (*rmnet_shs_stamp)(struct sk_buff *skb, struct rmnet_port *port);
+	void (*rmnet_shs_stamp)(struct sk_buff *skb, struct rmnet_port *port);
 	struct rmnet_priv *priv = netdev_priv(skb->dev);
 
 	trace_rmnet_low(RMNET_MODULE, RMNET_DLVR_SKB, 0xDEF, 0xDEF,