[PATCH] arp: Remove the arp_hh_ops structure

[Yejune Deng <yejune.deng@gmail.com>]

The arp_hh_ops structure is similar to the arp_generic_ops structure.
but the latter is more general,so remove the arp_hh_ops structure.

Fix when took out the neigh->ops assignment:
8.973653] #PF: supervisor read access in kernel mode
[    8.975027] #PF: error_code(0x0000) - not-present page
[    8.976310] PGD 0 P4D 0
[    8.977036] Oops: 0000 [#1] SMP PTI
[    8.977973] CPU: 1 PID: 210 Comm: sd-resolve Not tainted 5.11.0-rc7-02046-g4591591ab715 #1
[    8.979998] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
[    8.981996] RIP: 0010:neigh_probe (kbuild/src/consumer/net/core/neighbour.c:1009)

Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Yejune Deng <yejune.deng@gmail.com>
---
 net/ipv4/arp.c | 15 ++-------------
 1 file changed, 2 insertions(+), 13 deletions(-)

diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index 922dd73e5740..9ee59c2e419a 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -135,14 +135,6 @@ static const struct neigh_ops arp_generic_ops = {
 	.connected_output =	neigh_connected_output,
 };
 
-static const struct neigh_ops arp_hh_ops = {
-	.family =		AF_INET,
-	.solicit =		arp_solicit,
-	.error_report =		arp_error_report,
-	.output =		neigh_resolve_output,
-	.connected_output =	neigh_resolve_output,
-};
-
 static const struct neigh_ops arp_direct_ops = {
 	.family =		AF_INET,
 	.output =		neigh_direct_output,
@@ -277,12 +269,9 @@ static int arp_constructor(struct neighbour *neigh)
 			memcpy(neigh->ha, dev->broadcast, dev->addr_len);
 		}
 
-		if (dev->header_ops->cache)
-			neigh->ops = &arp_hh_ops;
-		else
-			neigh->ops = &arp_generic_ops;
+		neigh->ops = &arp_generic_ops;
 
-		if (neigh->nud_state & NUD_VALID)
+		if (!dev->header_ops->cache && (neigh->nud_state & NUD_VALID))
 			neigh->output = neigh->ops->connected_output;
 		else
 			neigh->output = neigh->ops->output;
-- 
2.29.0