Re: linux-2.6.12-rc1-mm4-RT-V0.7.42-08
On Mon, 2005-04-04 at 19:40 +0200, Ingo Molnar wrote:
> * Peter Zijlstra <[EMAIL PROTECTED]> wrote:
>
> > Hi Ingo,
> >
> > I need the following two patches to keep my system alive and avoid
> > the BUGs in the log send to you earlier (private mail).
>
> hm, the second patch does not apply (and the merge didnt look trivial) -
> maybe it depends on some patch in -mm that is not yet upstream?
>
I messed it up; apparently I type :wa to often and forgot to keep a
decent base file (yes I'm a vim user). I also seem to have gotten the
patch base dir wrong.
The two patches again; now hopefully with correct patch level and proper
base. They apply to my tree in order 2.6.12-rc1-icmp{,-rt}.patch.
Not ran nor compile tested on vanilla; just made then apply cleanly.
Could you please comment on the patches since I'm learning this stuff as
I go; and validation of my ideas would be most welcome. For instance;
was I right to convert the per cpu var __icmp_socket to a _LOCKED?
I think so since without the extra lock one could have race conditions
within the spin_trylock arguments double dereference.
Kind regards,
Peter Zijlstra
Since there is no lock held yet we are still preemptable; and since
icmp_socket is a per cpu variable switching cpus gives weird results.
Signed-off-by: Peter Zijlstra <[EMAIL PROTECTED]>
--- linux-2.6.12-rc1-RT-V0.7.42-08/net/ipv4/icmp_base.c 2005-04-04 20:26:23.0 +0200
+++ linux-2.6.12-rc1-RT-V0.7.42-08/net/ipv4/icmp.c 2005-04-04 20:26:38.0 +0200
@@ -376,8 +376,8 @@
static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
{
- struct sock *sk = icmp_socket->sk;
- struct inet_sock *inet = inet_sk(sk);
+ struct sock *sk;
+ struct inet_sock *inet;
struct ipcm_cookie ipc;
struct rtable *rt = (struct rtable *)skb->dst;
u32 daddr;
@@ -388,6 +388,9 @@
if (icmp_xmit_lock())
return;
+ sk = icmp_socket->sk;
+ inet = inet_sk(sk);
+
icmp_param->data.icmph.checksum = 0;
icmp_out_count(icmp_param->data.icmph.type);
Since on PREEMPT_RT spinlocks allow preemption, it's possible to
change cpu at (almost) any point in time. Make sure we stick to
the per cpu variable we started with.
Signed-off-by: Peter Zijlstra <[EMAIL PROTECTED]>
--- linux-2.6.12-rc1-RT-V0.7.42-08/net/ipv4/icmp_p1.c 2005-04-04 20:26:38.0 +0200
+++ linux-2.6.12-rc1-RT-V0.7.42-08/net/ipv4/icmp.c 2005-04-04 20:27:54.0 +0200
@@ -228,26 +228,32 @@
*
* On SMP we have one ICMP socket per-cpu.
*/
-static DEFINE_PER_CPU(struct socket *, __icmp_socket) = NULL;
-#define icmp_socket __get_cpu_var(__icmp_socket)
+static DEFINE_PER_CPU_LOCKED(struct socket *, __icmp_socket) = NULL;
-static __inline__ int icmp_xmit_lock(void)
+static __inline__ struct socket * icmp_xmit_lock(int cpu)
{
+ struct socket *icmp_socket;
+
local_bh_disable();
+ icmp_socket = get_cpu_var_locked(__icmp_socket, cpu);
if (unlikely(!spin_trylock(_socket->sk->sk_lock.slock))) {
/* This can happen if the output path signals a
* dst_link_failure() for an outgoing ICMP packet.
*/
+ put_cpu_var_locked(__icmp_socket, cpu);
local_bh_enable();
- return 1;
+ return NULL;
}
- return 0;
+
+ return icmp_socket;
}
-static void icmp_xmit_unlock(void)
+static void icmp_xmit_unlock(int cpu)
{
+ struct socket *icmp_socket = __get_cpu_var_locked(__icmp_socket, cpu);
spin_unlock_bh(_socket->sk->sk_lock.slock);
+ put_cpu_var_locked(__icmp_socket, cpu);
}
/*
@@ -344,7 +350,8 @@
}
static void icmp_push_reply(struct icmp_bxm *icmp_param,
- struct ipcm_cookie *ipc, struct rtable *rt)
+ struct ipcm_cookie *ipc, struct rtable *rt,
+struct socket *icmp_socket)
{
struct sk_buff *skb;
@@ -376,16 +383,19 @@
static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
{
+ struct socket *icmp_socket;
struct sock *sk;
struct inet_sock *inet;
struct ipcm_cookie ipc;
struct rtable *rt = (struct rtable *)skb->dst;
u32 daddr;
+ int cpu;
if (ip_options_echo(_param->replyopts, skb))
goto out;
- if (icmp_xmit_lock())
+ cpu = _smp_processor_id();
+ if (!(icmp_socket = icmp_xmit_lock(cpu)))
return;
sk = icmp_socket->sk;
@@ -413,10 +423,10 @@
}
if (icmpv4_xrlim_allow(rt, icmp_param->data.icmph.type,
icmp_param->data.icmph.code))
- icmp_push_reply(icmp_param, , rt);
+ icmp_push_reply(icmp_param, , rt, icmp_socket);
ip_rt_put(rt);
out_unlock:
- icmp_xmit_unlock();
+ icmp_xmit_unlock(cpu);
out:;
}
@@ -434,8 +444,9 @@
void icmp_send(struct sk_buff *skb_in, int type, int code, u32 info)
{
+ struct socket *icmp_socket;
struct iphdr *iph;
- int room;
+ int room, cpu;
struct icmp_bxm icmp_param;
struct rtable *rt = (struct rtable *)skb_in->dst;
struct ipcm_cookie ipc;
@@ -506,7 +517,8 @@
}
}
- if (icmp_xmit_lock())
+ cpu = _smp_processor_id();
+ if (!(icmp_socket = icmp_xmit_lock(cpu)))
return;
/*
@@ -579,11 +591,11 @@
icmp_param.data_len = room;
icmp_param.head_len = sizeof(struct
Re: linux-2.6.12-rc1-mm4-RT-V0.7.42-08
* Peter Zijlstra <[EMAIL PROTECTED]> wrote: > Hi Ingo, > > I need the following two patches to keep my system alive and avoid > the BUGs in the log send to you earlier (private mail). hm, the second patch does not apply (and the merge didnt look trivial) - maybe it depends on some patch in -mm that is not yet upstream? Ingo - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: linux-2.6.12-rc1-mm4-RT-V0.7.42-08
* Peter Zijlstra [EMAIL PROTECTED] wrote: Hi Ingo, I need the following two patches to keep my system alive and avoid the BUGs in the log send to you earlier (private mail). hm, the second patch does not apply (and the merge didnt look trivial) - maybe it depends on some patch in -mm that is not yet upstream? Ingo - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: linux-2.6.12-rc1-mm4-RT-V0.7.42-08
On Mon, 2005-04-04 at 19:40 +0200, Ingo Molnar wrote:
* Peter Zijlstra [EMAIL PROTECTED] wrote:
Hi Ingo,
I need the following two patches to keep my system alive and avoid
the BUGs in the log send to you earlier (private mail).
hm, the second patch does not apply (and the merge didnt look trivial) -
maybe it depends on some patch in -mm that is not yet upstream?
I messed it up; apparently I type :wa to often and forgot to keep a
decent base file (yes I'm a vim user). I also seem to have gotten the
patch base dir wrong.
The two patches again; now hopefully with correct patch level and proper
base. They apply to my tree in order 2.6.12-rc1-icmp{,-rt}.patch.
Not ran nor compile tested on vanilla; just made then apply cleanly.
Could you please comment on the patches since I'm learning this stuff as
I go; and validation of my ideas would be most welcome. For instance;
was I right to convert the per cpu var __icmp_socket to a _LOCKED?
I think so since without the extra lock one could have race conditions
within the spin_trylock arguments double dereference.
Kind regards,
Peter Zijlstra
Since there is no lock held yet we are still preemptable; and since
icmp_socket is a per cpu variable switching cpus gives weird results.
Signed-off-by: Peter Zijlstra [EMAIL PROTECTED]
--- linux-2.6.12-rc1-RT-V0.7.42-08/net/ipv4/icmp_base.c 2005-04-04 20:26:23.0 +0200
+++ linux-2.6.12-rc1-RT-V0.7.42-08/net/ipv4/icmp.c 2005-04-04 20:26:38.0 +0200
@@ -376,8 +376,8 @@
static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
{
- struct sock *sk = icmp_socket-sk;
- struct inet_sock *inet = inet_sk(sk);
+ struct sock *sk;
+ struct inet_sock *inet;
struct ipcm_cookie ipc;
struct rtable *rt = (struct rtable *)skb-dst;
u32 daddr;
@@ -388,6 +388,9 @@
if (icmp_xmit_lock())
return;
+ sk = icmp_socket-sk;
+ inet = inet_sk(sk);
+
icmp_param-data.icmph.checksum = 0;
icmp_out_count(icmp_param-data.icmph.type);
Since on PREEMPT_RT spinlocks allow preemption, it's possible to
change cpu at (almost) any point in time. Make sure we stick to
the per cpu variable we started with.
Signed-off-by: Peter Zijlstra [EMAIL PROTECTED]
--- linux-2.6.12-rc1-RT-V0.7.42-08/net/ipv4/icmp_p1.c 2005-04-04 20:26:38.0 +0200
+++ linux-2.6.12-rc1-RT-V0.7.42-08/net/ipv4/icmp.c 2005-04-04 20:27:54.0 +0200
@@ -228,26 +228,32 @@
*
* On SMP we have one ICMP socket per-cpu.
*/
-static DEFINE_PER_CPU(struct socket *, __icmp_socket) = NULL;
-#define icmp_socket __get_cpu_var(__icmp_socket)
+static DEFINE_PER_CPU_LOCKED(struct socket *, __icmp_socket) = NULL;
-static __inline__ int icmp_xmit_lock(void)
+static __inline__ struct socket * icmp_xmit_lock(int cpu)
{
+ struct socket *icmp_socket;
+
local_bh_disable();
+ icmp_socket = get_cpu_var_locked(__icmp_socket, cpu);
if (unlikely(!spin_trylock(icmp_socket-sk-sk_lock.slock))) {
/* This can happen if the output path signals a
* dst_link_failure() for an outgoing ICMP packet.
*/
+ put_cpu_var_locked(__icmp_socket, cpu);
local_bh_enable();
- return 1;
+ return NULL;
}
- return 0;
+
+ return icmp_socket;
}
-static void icmp_xmit_unlock(void)
+static void icmp_xmit_unlock(int cpu)
{
+ struct socket *icmp_socket = __get_cpu_var_locked(__icmp_socket, cpu);
spin_unlock_bh(icmp_socket-sk-sk_lock.slock);
+ put_cpu_var_locked(__icmp_socket, cpu);
}
/*
@@ -344,7 +350,8 @@
}
static void icmp_push_reply(struct icmp_bxm *icmp_param,
- struct ipcm_cookie *ipc, struct rtable *rt)
+ struct ipcm_cookie *ipc, struct rtable *rt,
+struct socket *icmp_socket)
{
struct sk_buff *skb;
@@ -376,16 +383,19 @@
static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
{
+ struct socket *icmp_socket;
struct sock *sk;
struct inet_sock *inet;
struct ipcm_cookie ipc;
struct rtable *rt = (struct rtable *)skb-dst;
u32 daddr;
+ int cpu;
if (ip_options_echo(icmp_param-replyopts, skb))
goto out;
- if (icmp_xmit_lock())
+ cpu = _smp_processor_id();
+ if (!(icmp_socket = icmp_xmit_lock(cpu)))
return;
sk = icmp_socket-sk;
@@ -413,10 +423,10 @@
}
if (icmpv4_xrlim_allow(rt, icmp_param-data.icmph.type,
icmp_param-data.icmph.code))
- icmp_push_reply(icmp_param, ipc, rt);
+ icmp_push_reply(icmp_param, ipc, rt, icmp_socket);
ip_rt_put(rt);
out_unlock:
- icmp_xmit_unlock();
+ icmp_xmit_unlock(cpu);
out:;
}
@@ -434,8 +444,9 @@
void icmp_send(struct sk_buff *skb_in, int type, int code, u32 info)
{
+ struct socket *icmp_socket;
struct iphdr *iph;
- int room;
+ int room, cpu;
struct icmp_bxm icmp_param;
struct rtable *rt = (struct rtable *)skb_in-dst;
struct ipcm_cookie ipc;
@@ -506,7 +517,8 @@
}
}
- if (icmp_xmit_lock())
+ cpu = _smp_processor_id();
+ if (!(icmp_socket = icmp_xmit_lock(cpu)))
return;
/*
@@ -579,11 +591,11 @@
icmp_param.data_len = room;
icmp_param.head_len = sizeof(struct icmphdr);
-
Re: linux-2.6.12-rc1-mm4-RT-V0.7.42-08
Hi Ingo,
I need the following two patches to keep my system alive and avoid
the BUGs in the log send to you earlier (private mail).
--- example BUG
BUG: using smp_processor_id() in preemptible [0001] code: java/16460
caller is icmp_send+0x9b/0x3d0
[] smp_processor_id+0x9b/0xb0 (8)
[] icmp_send+0x9b/0x3d0 (28)
[] check_wakeup_timing+0x47/0x160 (8)
[] _raw_spin_unlock+0xd/0x30 (40)
[] kmem_cache_free+0x39/0x120 (8)
[] _raw_spin_unlock+0xd/0x30 (12)
[] kmem_cache_free+0x39/0x120 (8)
[] _raw_spin_unlock+0xd/0x30 (24)
[] _raw_spin_unlock+0xd/0x30 (28)
[] rtl8139_start_xmit+0x86/0x1d0 (8)
[] _raw_spin_unlock+0xd/0x30 (40)
[] qdisc_restart+0x1b9/0x230 (8)
[] qdisc_restart+0x1b9/0x230 (36)
[] _raw_spin_unlock+0xd/0x30 (8)
[] rtl8139_start_xmit+0xce/0x1d0 (16)
[] _raw_spin_unlock+0xd/0x30 (32)
[] ip_fragment+0x663/0x7f0 (60)
[] rcu_read_unlock+0x5f/0x70 (32)
[] __ip_route_output_key+0xba/0xe0 (8)
[] ip_finish_output+0x0/0x2f0 (16)
[] ip_queue_xmit+0x263/0x590 (24)
[] ip_queue_xmit+0x263/0x590 (20)
[] tcp_transmit_skb+0x38b/0x750 (196)
[] tcp_write_xmit+0x10e/0x2f0 (56)
[] tcp_sendmsg+0xffb/0x1050 (52)
[] _raw_spin_unlock+0xd/0x30 (12)
[] unqueue_me+0x25/0x130 (8)
[] inet_sendmsg+0x4a/0x70 (92)
[] sock_aio_write+0x135/0x150 (24)
[] _raw_spin_unlock+0xd/0x30 (88)
[] do_sync_write+0xb9/0x110 (20)
[] _raw_spin_unlock+0xd/0x30 (44)
[] fget_light+0x62/0x90 (8)
[] _raw_spin_unlock+0xd/0x30 (44)
[] autoremove_wake_function+0x0/0x50 (8)
[] vfs_write+0xdb/0x170 (52)
[] sys_write+0x41/0x70 (24)
[] sysenter_past_esp+0x54/0x75 (28)
---
| preempt count: 0002 ]
| 2-level deep critical section nesting:
.. [] _raw_spin_lock+0x16/0x90
.[<>] .. ( <= 0x0)
.. [] _raw_spin_lock+0x16/0x90
.[<>] .. ( <= 0x0)
--
Peter Zijlstra <[EMAIL PROTECTED]>
Since there is no lock held yet we are still preemptable; and since
icmp_socket is a per cpu variable switching cpus gives weird results.
Signed-off-by: Peter Zijlstra <[EMAIL PROTECTED]>
--- /usr/src/linux-2.6.12-rc1-mm4-RT-V0.7.42-08/net/ipv4/icmp.c~ 2005-03-25 10:14:32.0 +0100
+++ /usr/src/linux-2.6.12-rc1-mm4-RT-V0.7.42-08/net/ipv4/icmp.c 2005-04-02 18:58:19.0 +0200
@@ -376,8 +376,8 @@
static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
{
- struct sock *sk = icmp_socket->sk;
- struct inet_sock *inet = inet_sk(sk);
+ struct sock *sk;
+ struct inet_sock *inet;
struct ipcm_cookie ipc;
struct rtable *rt = (struct rtable *)skb->dst;
u32 daddr;
@@ -388,6 +388,9 @@
if (icmp_xmit_lock())
return;
+ sk = icmp_socket->sk;
+ inet = inet_sk(sk);
+
icmp_param->data.icmph.checksum = 0;
icmp_out_count(icmp_param->data.icmph.type);
Since on PREEMPT_RT spinlocks allow preemption, it's possible to
change cpu at (almost) any point in time. Make sure we stick to
the per cpu variable we started with.
Signed-off-by: Peter Zijlstra <[EMAIL PROTECTED]>
--- /usr/src/linux-2.6.12-rc1-mm4-RT-V0.7.42-08/net/ipv4/icmp_orig.c 2005-04-03 00:09:08.00000 +0200
+++ /usr/src/linux-2.6.12-rc1-mm4-RT-V0.7.42-08/net/ipv4/icmp.c 2005-04-03 00:20:22.0 +0200
@@ -228,27 +228,32 @@
*
* On SMP we have one ICMP socket per-cpu.
*/
-static DEFINE_PER_CPU(struct socket *, __icmp_socket) = NULL;
-#define icmp_socket __get_cpu_var(__icmp_socket)
+static DEFINE_PER_CPU_LOCKED(struct socket *, __icmp_socket) = NULL;
static __inline__ struct socket * icmp_xmit_lock(int cpu)
{
+ struct socket *icmp_socket;
+
local_bh_disable();
+ icmp_socket = get_cpu_var_locked(__icmp_socket, cpu);
if (unlikely(!spin_trylock(_socket->sk->sk_lock.slock))) {
/* This can happen if the output path signals a
* dst_link_failure() for an outgoing ICMP packet.
*/
+ put_cpu_var_locked(__icmp_socket, cpu);
local_bh_enable();
- return 1;
+ return NULL;
}
- return 0;
+ return icmp_socket;
}
static void icmp_xmit_unlock(int cpu)
{
+ struct socket *icmp_socket = __get_cpu_var_locked(__icmp_socket, cpu);
spin_unlock_bh(_socket->sk->sk_lock.slock);
+ put_cpu_var_locked(__icmp_socket, cpu);
}
/*
@@ -345,7 +350,8 @@
}
static void icmp_push_reply(struct icmp_bxm *icmp_param,
- struct ipcm_cookie *ipc, struct rtable *rt)
+ struct ipcm_cookie *ipc, struct rtable *rt,
+struct socket *icmp_socket)
{
struct sk_buff *skb;
@@ -377,16 +383,19 @@
static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
{
+ struct socket *icmp_socket;
struct sock *sk;
struct inet_sock *inet;
struct ipcm_cookie ipc;
struct rtable *rt = (struct rtable *)skb->dst;
u32 daddr;
+ int cpu;
if (ip_options_echo(_param->replyopts, skb))
goto out;
- if (icmp_xmit_lock())
+ cpu = _smp_processor_id();
+ if (!(icmp_socket = icmp_xmit_lock(cpu)))
return;
sk = i
Re: linux-2.6.12-rc1-mm4-RT-V0.7.42-08
Hi Ingo,
I need the following two patches to keep my system alive and avoid
the BUGs in the log send to you earlier (private mail).
--- example BUG
BUG: using smp_processor_id() in preemptible [0001] code: java/16460
caller is icmp_send+0x9b/0x3d0
[c020b1db] smp_processor_id+0x9b/0xb0 (8)
[c032246b] icmp_send+0x9b/0x3d0 (28)
[c013ae67] check_wakeup_timing+0x47/0x160 (8)
[c034269d] _raw_spin_unlock+0xd/0x30 (40)
[c014d159] kmem_cache_free+0x39/0x120 (8)
[c034269d] _raw_spin_unlock+0xd/0x30 (12)
[c014d159] kmem_cache_free+0x39/0x120 (8)
[c034269d] _raw_spin_unlock+0xd/0x30 (24)
[c034269d] _raw_spin_unlock+0xd/0x30 (28)
[c0276066] rtl8139_start_xmit+0x86/0x1d0 (8)
[c034269d] _raw_spin_unlock+0xd/0x30 (40)
[c02f3259] qdisc_restart+0x1b9/0x230 (8)
[c02f3259] qdisc_restart+0x1b9/0x230 (36)
[c034269d] _raw_spin_unlock+0xd/0x30 (8)
[c02760ae] rtl8139_start_xmit+0xce/0x1d0 (16)
[c034269d] _raw_spin_unlock+0xd/0x30 (32)
[c02ffe33] ip_fragment+0x663/0x7f0 (60)
[c013138f] rcu_read_unlock+0x5f/0x70 (32)
[c02f9d2a] __ip_route_output_key+0xba/0xe0 (8)
[c02fe950] ip_finish_output+0x0/0x2f0 (16)
[c02ff383] ip_queue_xmit+0x263/0x590 (24)
[c02ff383] ip_queue_xmit+0x263/0x590 (20)
[c03102eb] tcp_transmit_skb+0x38b/0x750 (196)
[c031113e] tcp_write_xmit+0x10e/0x2f0 (56)
[c03054ab] tcp_sendmsg+0xffb/0x1050 (52)
[c034269d] _raw_spin_unlock+0xd/0x30 (12)
[c013b9c5] unqueue_me+0x25/0x130 (8)
[c0325f4a] inet_sendmsg+0x4a/0x70 (92)
[c02dd795] sock_aio_write+0x135/0x150 (24)
[c034269d] _raw_spin_unlock+0xd/0x30 (88)
[c0163c69] do_sync_write+0xb9/0x110 (20)
[c034269d] _raw_spin_unlock+0xd/0x30 (44)
[c0164d52] fget_light+0x62/0x90 (8)
[c034269d] _raw_spin_unlock+0xd/0x30 (44)
[c0134c50] autoremove_wake_function+0x0/0x50 (8)
[c0163d9b] vfs_write+0xdb/0x170 (52)
[c0163ee1] sys_write+0x41/0x70 (24)
[c0102f0b] sysenter_past_esp+0x54/0x75 (28)
---
| preempt count: 0002 ]
| 2-level deep critical section nesting:
.. [c03422e6] _raw_spin_lock+0x16/0x90
.[] .. ( = 0x0)
.. [c03422e6] _raw_spin_lock+0x16/0x90
.[] .. ( = 0x0)
--
Peter Zijlstra [EMAIL PROTECTED]
Since there is no lock held yet we are still preemptable; and since
icmp_socket is a per cpu variable switching cpus gives weird results.
Signed-off-by: Peter Zijlstra [EMAIL PROTECTED]
--- /usr/src/linux-2.6.12-rc1-mm4-RT-V0.7.42-08/net/ipv4/icmp.c~ 2005-03-25 10:14:32.0 +0100
+++ /usr/src/linux-2.6.12-rc1-mm4-RT-V0.7.42-08/net/ipv4/icmp.c 2005-04-02 18:58:19.0 +0200
@@ -376,8 +376,8 @@
static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
{
- struct sock *sk = icmp_socket-sk;
- struct inet_sock *inet = inet_sk(sk);
+ struct sock *sk;
+ struct inet_sock *inet;
struct ipcm_cookie ipc;
struct rtable *rt = (struct rtable *)skb-dst;
u32 daddr;
@@ -388,6 +388,9 @@
if (icmp_xmit_lock())
return;
+ sk = icmp_socket-sk;
+ inet = inet_sk(sk);
+
icmp_param-data.icmph.checksum = 0;
icmp_out_count(icmp_param-data.icmph.type);
Since on PREEMPT_RT spinlocks allow preemption, it's possible to
change cpu at (almost) any point in time. Make sure we stick to
the per cpu variable we started with.
Signed-off-by: Peter Zijlstra [EMAIL PROTECTED]
--- /usr/src/linux-2.6.12-rc1-mm4-RT-V0.7.42-08/net/ipv4/icmp_orig.c 2005-04-03 00:09:08.0 +0200
+++ /usr/src/linux-2.6.12-rc1-mm4-RT-V0.7.42-08/net/ipv4/icmp.c 2005-04-03 00:20:22.0 +0200
@@ -228,27 +228,32 @@
*
* On SMP we have one ICMP socket per-cpu.
*/
-static DEFINE_PER_CPU(struct socket *, __icmp_socket) = NULL;
-#define icmp_socket __get_cpu_var(__icmp_socket)
+static DEFINE_PER_CPU_LOCKED(struct socket *, __icmp_socket) = NULL;
static __inline__ struct socket * icmp_xmit_lock(int cpu)
{
+ struct socket *icmp_socket;
+
local_bh_disable();
+ icmp_socket = get_cpu_var_locked(__icmp_socket, cpu);
if (unlikely(!spin_trylock(icmp_socket-sk-sk_lock.slock))) {
/* This can happen if the output path signals a
* dst_link_failure() for an outgoing ICMP packet.
*/
+ put_cpu_var_locked(__icmp_socket, cpu);
local_bh_enable();
- return 1;
+ return NULL;
}
- return 0;
+ return icmp_socket;
}
static void icmp_xmit_unlock(int cpu)
{
+ struct socket *icmp_socket = __get_cpu_var_locked(__icmp_socket, cpu);
spin_unlock_bh(icmp_socket-sk-sk_lock.slock);
+ put_cpu_var_locked(__icmp_socket, cpu);
}
/*
@@ -345,7 +350,8 @@
}
static void icmp_push_reply(struct icmp_bxm *icmp_param,
- struct ipcm_cookie *ipc, struct rtable *rt)
+ struct ipcm_cookie *ipc, struct rtable *rt,
+struct socket *icmp_socket)
{
struct sk_buff *skb;
@@ -377,16 +383,19 @@
static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
{
+ struct socket *icmp_socket;
struct sock *sk;
struct inet_sock *inet;
struct ipcm_cookie ipc;
struct rtable *rt
