[patch 068/101] Fix TCP MD5 locking.

From: Greg KH
Date: Wed Mar 07 2007 - 12:30:55 EST


From: David Miller <davem@xxxxxxxxxxxxx>

[TCP]: Fix MD5 signature pool locking.

The locking calls assumed that these code paths were only
invoked in software interrupt context, but that isn't true.

Therefore we need to use spin_{lock,unlock}_bh() throughout.

Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
net/ipv4/tcp.c | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)

--- linux-2.6.20.1.orig/net/ipv4/tcp.c
+++ linux-2.6.20.1/net/ipv4/tcp.c
@@ -2266,12 +2266,12 @@ void tcp_free_md5sig_pool(void)
{
struct tcp_md5sig_pool **pool = NULL;

- spin_lock(&tcp_md5sig_pool_lock);
+ spin_lock_bh(&tcp_md5sig_pool_lock);
if (--tcp_md5sig_users == 0) {
pool = tcp_md5sig_pool;
tcp_md5sig_pool = NULL;
}
- spin_unlock(&tcp_md5sig_pool_lock);
+ spin_unlock_bh(&tcp_md5sig_pool_lock);
if (pool)
__tcp_free_md5sig_pool(pool);
}
@@ -2314,36 +2314,36 @@ struct tcp_md5sig_pool **tcp_alloc_md5si
int alloc = 0;

retry:
- spin_lock(&tcp_md5sig_pool_lock);
+ spin_lock_bh(&tcp_md5sig_pool_lock);
pool = tcp_md5sig_pool;
if (tcp_md5sig_users++ == 0) {
alloc = 1;
- spin_unlock(&tcp_md5sig_pool_lock);
+ spin_unlock_bh(&tcp_md5sig_pool_lock);
} else if (!pool) {
tcp_md5sig_users--;
- spin_unlock(&tcp_md5sig_pool_lock);
+ spin_unlock_bh(&tcp_md5sig_pool_lock);
cpu_relax();
goto retry;
} else
- spin_unlock(&tcp_md5sig_pool_lock);
+ spin_unlock_bh(&tcp_md5sig_pool_lock);

if (alloc) {
/* we cannot hold spinlock here because this may sleep. */
struct tcp_md5sig_pool **p = __tcp_alloc_md5sig_pool();
- spin_lock(&tcp_md5sig_pool_lock);
+ spin_lock_bh(&tcp_md5sig_pool_lock);
if (!p) {
tcp_md5sig_users--;
- spin_unlock(&tcp_md5sig_pool_lock);
+ spin_unlock_bh(&tcp_md5sig_pool_lock);
return NULL;
}
pool = tcp_md5sig_pool;
if (pool) {
/* oops, it has already been assigned. */
- spin_unlock(&tcp_md5sig_pool_lock);
+ spin_unlock_bh(&tcp_md5sig_pool_lock);
__tcp_free_md5sig_pool(p);
} else {
tcp_md5sig_pool = pool = p;
- spin_unlock(&tcp_md5sig_pool_lock);
+ spin_unlock_bh(&tcp_md5sig_pool_lock);
}
}
return pool;
@@ -2354,11 +2354,11 @@ EXPORT_SYMBOL(tcp_alloc_md5sig_pool);
struct tcp_md5sig_pool *__tcp_get_md5sig_pool(int cpu)
{
struct tcp_md5sig_pool **p;
- spin_lock(&tcp_md5sig_pool_lock);
+ spin_lock_bh(&tcp_md5sig_pool_lock);
p = tcp_md5sig_pool;
if (p)
tcp_md5sig_users++;
- spin_unlock(&tcp_md5sig_pool_lock);
+ spin_unlock_bh(&tcp_md5sig_pool_lock);
return (p ? *per_cpu_ptr(p, cpu) : NULL);
}


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