[PATCH net-next] net neighbour,decnet: Ensure to align device privatedata on preferred alignment.

From: YOSHIFUJI Hideaki
Date: Sat Feb 09 2013 - 12:01:05 EST


To allow both of protocol-specific data and device-specific data
attached with neighbour entry, and to eliminate size calculation
cost when allocating entry, sizeof protocol-speicic data must be
multiple of NEIGH_PRIV_ALIGN. On 64bit archs,
sizeof(struct dn_neigh) is multiple of NEIGH_PRIV_ALIGN, but on
32bit archs, it was not.

Introduce NEIGH_ENTRY_SPACE() macro to ensure that protocol-specific
entry-size meets our requirement.

Reported-by: Fengguang Wu <fengguang.wu@xxxxxxxxx>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@xxxxxxxxxxxxxx>
---
include/net/neighbour.h | 1 +
net/decnet/dn_neigh.c | 2 +-
2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/net/neighbour.h b/include/net/neighbour.h
index 629ee57..7e748ad 100644
--- a/include/net/neighbour.h
+++ b/include/net/neighbour.h
@@ -181,6 +181,7 @@ struct neigh_table {
};

#define NEIGH_PRIV_ALIGN sizeof(long long)
+#define NEIGH_ENTRY_SIZE(size) ALIGN((size), NEIGH_PRIV_ALIGN)

static inline void *neighbour_priv(const struct neighbour *n)
{
diff --git a/net/decnet/dn_neigh.c b/net/decnet/dn_neigh.c
index 3aede1b..856636a 100644
--- a/net/decnet/dn_neigh.c
+++ b/net/decnet/dn_neigh.c
@@ -95,7 +95,7 @@ static u32 dn_neigh_hash(const void *pkey,

struct neigh_table dn_neigh_table = {
.family = PF_DECnet,
- .entry_size = sizeof(struct dn_neigh),
+ .entry_size = NEIGH_ENTRY_SIZE(sizeof(struct dn_neigh)),
.key_len = sizeof(__le16),
.hash = dn_neigh_hash,
.constructor = dn_neigh_construct,
--
1.7.9.5

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