Messages in this thread Patch in this message | | | Date | Fri, 17 Aug 2012 09:07:04 +0800 | From | Fan Du <> | Subject | Re: suspicious RCU usage in xfrm_net_init() |
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On 2012年08月16日 23:19, Fengguang Wu wrote: > Hi Fan, > > On Thu, Aug 16, 2012 at 05:36:35PM +0800, Fan Du wrote: >> >> Hi, Fengguang >> >> Could you please try the below patch, see if spewing still there? >> thanks > > Yes, it worked, thank you very much! >
Hi, Dave
Could you please pick up this patch? thanks
> btw, your email client wraps long lines.. > Oh, I will definitely fix this. thanks feng guang for the testing :)
> Thanks, > Fengguang > >> From a3f86ecc3ee16ff81d49416bbf791780422988b3 Mon Sep 17 00:00:00 2001 >> From: Fan Du<fan.du@windriver.com> >> Date: Thu, 16 Aug 2012 17:31:25 +0800 >> Subject: [PATCH] Use rcu_dereference_bh to deference pointer >> protected by rcu_read_lock_bh >> >> Signed-off-by: Fan Du<fan.du@windriver.com> >> --- >> net/xfrm/xfrm_policy.c | 2 +- >> 1 files changed, 1 insertions(+), 1 deletions(-) >> >> diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c >> index 5ad4d2c..75a9d6a 100644 >> --- a/net/xfrm/xfrm_policy.c >> +++ b/net/xfrm/xfrm_policy.c >> @@ -2501,7 +2501,7 @@ static void __net_init >> xfrm_dst_ops_init(struct net *net) >> struct xfrm_policy_afinfo *afinfo; >> >> rcu_read_lock_bh(); >> - afinfo = rcu_dereference(xfrm_policy_afinfo[AF_INET]); >> + afinfo = rcu_dereference_bh(xfrm_policy_afinfo[AF_INET]); >> if (afinfo) >> net->xfrm.xfrm4_dst_ops = *afinfo->dst_ops; >> #if IS_ENABLED(CONFIG_IPV6) >> -- >> 1.7.1 >> >> >> >> >> On 2012年08月16日 15:37, Fengguang Wu wrote: >>> Hi Priyanka, >>> >>> The below warning shows up, probably related to this commit: >>> >>> 418a99ac6ad487dc9c42e6b0e85f941af56330f2 Replace rwlock on xfrm_policy_afinfo with rcu >>> >>> [ 0.921216] >>> [ 0.921645] =============================== >>> [ 0.922766] [ INFO: suspicious RCU usage. ] >>> [ 0.923887] 3.5.0-01540-g1669891 #64 Not tainted >>> [ 0.925123] ------------------------------- >>> [ 0.932860] /c/kernel-tests/src/tip/net/xfrm/xfrm_policy.c:2504 suspicious rcu_dereference_check() usage! >>> [ 0.935361] >>> [ 0.935361] other info that might help us debug this: >>> [ 0.935361] >>> [ 0.937472] >>> [ 0.937472] rcu_scheduler_active = 1, debug_locks = 0 >>> [ 0.939182] 2 locks held by swapper/1: >>> [ 0.940171] #0: (net_mutex){+.+.+.}, at: [<ffffffff814e1ad0>] register_pernet_subsys+0x21/0x57 >>> [ 0.942705] #1: (rcu_read_lock_bh){......}, at: [<ffffffff822c7329>] xfrm_net_init+0x1e4/0x437 >>> [ 0.951507] >>> [ 0.951507] stack backtrace: >>> [ 0.952660] Pid: 1, comm: swapper Not tainted 3.5.0-01540-g1669891 #64 >>> [ 0.954364] Call Trace: >>> [ 0.955074] [<ffffffff8108b375>] lockdep_rcu_suspicious+0x174/0x187 >>> [ 0.956736] [<ffffffff822c7453>] xfrm_net_init+0x30e/0x437 >>> [ 0.958205] [<ffffffff822c7329>] ? xfrm_net_init+0x1e4/0x437 >>> [ 0.959712] [<ffffffff814e134a>] ops_init+0x1bb/0x1ff >>> [ 0.961067] [<ffffffff810861f9>] ? trace_hardirqs_on+0x1b/0x24 >>> [ 0.962644] [<ffffffff814e17cd>] register_pernet_operations.isra.5+0x9d/0xfe >>> [ 0.971376] [<ffffffff814e1adf>] register_pernet_subsys+0x30/0x57 >>> [ 0.972992] [<ffffffff822c7130>] xfrm_init+0x17/0x2c >>> [ 0.974316] [<ffffffff822c2f8c>] ip_rt_init+0x82/0xe7 >>> [ 0.975668] [<ffffffff822c31dc>] ip_init+0x10/0x25 >>> [ 0.976952] [<ffffffff822c3f77>] inet_init+0x235/0x360 >>> [ 0.978352] [<ffffffff822c3d42>] ? devinet_init+0xf2/0xf2 >>> [ 0.979808] [<ffffffff82283252>] do_one_initcall+0xb4/0x203 >>> [ 0.981313] [<ffffffff8228354a>] kernel_init+0x1a9/0x29a >>> [ 0.982732] [<ffffffff822826d9>] ? loglevel+0x46/0x46 >>> [ 0.990889] [<ffffffff816d3d84>] kernel_thread_helper+0x4/0x10 >>> [ 0.992472] [<ffffffff816d262c>] ? retint_restore_args+0x13/0x13 >>> [ 0.994076] [<ffffffff822833a1>] ? do_one_initcall+0x203/0x203 >>> [ 0.995636] [<ffffffff816d3d80>] ? gs_change+0x13/0x13 >>> [ 0.997197] TCP established hash table entries: 8192 (order: 5, 131072 bytes) >>> [ 1.000074] TCP bind hash table entries: 8192 (order: 7, 655360 bytes) >>> >>> Thanks, >>> Fengguang >> >> -- >> >> Love each day! >> --fan >
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Love each day! --fan From f3b4d84f7ca2ed235c8c8ae5186f45e20b9b80db Mon Sep 17 00:00:00 2001 From: Fan Du <fan.du@windriver.com> Date: Thu, 16 Aug 2012 17:51:25 +0800 Subject: [PATCH] Use rcu_dereference_bh to deference pointer protected by rcu_read_lock_bh
Signed-off-by: Fan Du <fan.du@windriver.com> --- net/xfrm/xfrm_policy.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c index 5ad4d2c..6405764 100644 --- a/net/xfrm/xfrm_policy.c +++ b/net/xfrm/xfrm_policy.c @@ -2501,11 +2501,11 @@ static void __net_init xfrm_dst_ops_init(struct net *net) struct xfrm_policy_afinfo *afinfo; rcu_read_lock_bh(); - afinfo = rcu_dereference(xfrm_policy_afinfo[AF_INET]); + afinfo = rcu_dereference_bh(xfrm_policy_afinfo[AF_INET]); if (afinfo) net->xfrm.xfrm4_dst_ops = *afinfo->dst_ops; #if IS_ENABLED(CONFIG_IPV6) - afinfo = rcu_dereference(xfrm_policy_afinfo[AF_INET6]); + afinfo = rcu_dereference_bh(xfrm_policy_afinfo[AF_INET6]); if (afinfo) net->xfrm.xfrm6_dst_ops = *afinfo->dst_ops; #endif -- 1.7.1
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