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Subject[PATCH 4.18 019/197] tipc: fix the big/little endian issue in tipc_dest
Date
4.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Haiqing Bai <Haiqing.Bai@windriver.com>

[ Upstream commit 30935198b7d0be12b1c45c328b66a7fdefb16256 ]

In function tipc_dest_push, the 32bit variables 'node' and 'port'
are stored separately in uppper and lower part of 64bit 'value'.
Then this value is assigned to dst->value which is a union like:
union
{
struct {
u32 port;
u32 node;
};
u64 value;
}
This works on little-endian machines like x86 but fails on big-endian
machines.

The fix remove the 'value' stack parameter and even the 'value'
member of the union in tipc_dest, assign the 'node' and 'port' member
directly with the input parameter to avoid the endian issue.

Fixes: a80ae5306a73 ("tipc: improve destination linked list")
Signed-off-by: Zhenbo Gao <zhenbo.gao@windriver.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Haiqing Bai <Haiqing.Bai@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/tipc/name_table.c | 10 ++++------
net/tipc/name_table.h | 9 ++-------
2 files changed, 6 insertions(+), 13 deletions(-)

--- a/net/tipc/name_table.c
+++ b/net/tipc/name_table.c
@@ -980,20 +980,17 @@ int tipc_nl_name_table_dump(struct sk_bu

struct tipc_dest *tipc_dest_find(struct list_head *l, u32 node, u32 port)
{
- u64 value = (u64)node << 32 | port;
struct tipc_dest *dst;

list_for_each_entry(dst, l, list) {
- if (dst->value != value)
- continue;
- return dst;
+ if (dst->node == node && dst->port == port)
+ return dst;
}
return NULL;
}

bool tipc_dest_push(struct list_head *l, u32 node, u32 port)
{
- u64 value = (u64)node << 32 | port;
struct tipc_dest *dst;

if (tipc_dest_find(l, node, port))
@@ -1002,7 +999,8 @@ bool tipc_dest_push(struct list_head *l,
dst = kmalloc(sizeof(*dst), GFP_ATOMIC);
if (unlikely(!dst))
return false;
- dst->value = value;
+ dst->node = node;
+ dst->port = port;
list_add(&dst->list, l);
return true;
}
--- a/net/tipc/name_table.h
+++ b/net/tipc/name_table.h
@@ -133,13 +133,8 @@ void tipc_nametbl_stop(struct net *net);

struct tipc_dest {
struct list_head list;
- union {
- struct {
- u32 port;
- u32 node;
- };
- u64 value;
- };
+ u32 port;
+ u32 node;
};

struct tipc_dest *tipc_dest_find(struct list_head *l, u32 node, u32 port);

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