From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org,
linux-rt-users <linux-rt-users@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Carsten Emde <C.Emde@osadl.org>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
John Kacur <jkacur@redhat.com>,
Paul Gortmaker <paul.gortmaker@windriver.com>,
<stable-rt@vger.kernel.org>
Subject: [PATCH RT 4/7] net: add a lock around icmp_sk()
Date: Fri, 23 Sep 2016 15:50:12 -0400 [thread overview]
Message-ID: <20160923195019.571759547@goodmis.org> (raw)
In-Reply-To: 20160923195008.543008518@goodmis.org
[-- Attachment #1: 0004-net-add-a-lock-around-icmp_sk.patch --]
[-- Type: text/plain, Size: 2321 bytes --]
3.2.82-rt119-rc1 stable review patch.
If anyone has any objections, please let me know.
------------------
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
It looks like the this_cpu_ptr() access in icmp_sk() is protected with
local_bh_disable(). To avoid missing serialization in -RT I am adding
here a local lock. No crash has been observed, this is just precaution.
Cc: stable-rt@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
net/ipv4/icmp.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 028eb47226e8..e232225f7446 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -76,6 +76,7 @@
#include <linux/string.h>
#include <linux/netfilter_ipv4.h>
#include <linux/slab.h>
+#include <linux/locallock.h>
#include <net/snmp.h>
#include <net/ip.h>
#include <net/route.h>
@@ -202,6 +203,8 @@ static const struct icmp_control icmp_pointers[NR_ICMP_TYPES+1];
*
* On SMP we have one ICMP socket per-cpu.
*/
+static DEFINE_LOCAL_IRQ_LOCK(icmp_sk_lock);
+
static struct sock *icmp_sk(struct net *net)
{
return net->ipv4.icmp_sk[smp_processor_id()];
@@ -213,12 +216,14 @@ static inline struct sock *icmp_xmit_lock(struct net *net)
local_bh_disable();
+ local_lock(icmp_sk_lock);
sk = icmp_sk(net);
if (unlikely(!spin_trylock(&sk->sk_lock.slock))) {
/* This can happen if the output path signals a
* dst_link_failure() for an outgoing ICMP packet.
*/
+ local_unlock(icmp_sk_lock);
local_bh_enable();
return NULL;
}
@@ -228,6 +233,7 @@ static inline struct sock *icmp_xmit_lock(struct net *net)
static inline void icmp_xmit_unlock(struct sock *sk)
{
spin_unlock_bh(&sk->sk_lock.slock);
+ local_unlock(icmp_sk_lock);
}
/*
@@ -298,6 +304,7 @@ static void icmp_push_reply(struct icmp_bxm *icmp_param,
struct sock *sk;
struct sk_buff *skb;
+ local_lock(icmp_sk_lock);
sk = icmp_sk(dev_net((*rt)->dst.dev));
if (ip_append_data(sk, fl4, icmp_glue_bits, icmp_param,
icmp_param->data_len+icmp_param->head_len,
@@ -320,6 +327,7 @@ static void icmp_push_reply(struct icmp_bxm *icmp_param,
skb->ip_summed = CHECKSUM_NONE;
ip_push_pending_frames(sk, fl4);
}
+ local_unlock(icmp_sk_lock);
}
/*
--
2.8.1
next prev parent reply other threads:[~2016-09-23 19:50 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-23 19:50 [PATCH RT 0/7] Linux 3.2.82-rt119-rc1 Steven Rostedt
2016-09-23 19:50 ` [PATCH RT 1/7] timers: wakeup all timer waiters Steven Rostedt
2016-09-23 19:50 ` [PATCH RT 2/7] timers: wakeup all timer waiters without holding the base lock Steven Rostedt
2016-09-23 19:50 ` Steven Rostedt [this message]
2016-09-23 19:50 ` [PATCH RT 5/7] fs/dcache: resched/chill only if we make no progress Steven Rostedt
2016-09-23 19:50 ` [PATCH RT 6/7] fs/dcache: incremental fixup of the retry routine Steven Rostedt
2016-09-23 19:50 ` [PATCH RT 7/7] Linux 3.2.82-rt119-rc1 Steven Rostedt
[not found] ` <20160923195019.349112022@goodmis.org>
2016-09-23 19:58 ` [PATCH RT 3/7] net: add back the missing serialization in ip_send_unicast_reply() Steven Rostedt
-- strict thread matches above, loose matches on Subject: below --
2016-09-23 16:48 [PATCH RT 0/7] Linux 3.4.112-rt144-rc1 Steven Rostedt
2016-09-23 16:48 ` [PATCH RT 4/7] net: add a lock around icmp_sk() Steven Rostedt
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