| Message ID | 205259E8-A99F-4573-96C9-7A394235B338@intel.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Wed, 2012-07-18 at 17:36 +0000, Rustad, Mark D wrote: > On Jul 18, 2012, at 6:04 AM, Neil Horman wrote: > > > John, can you post the backtrace you got for this? I replied to the patch that > > you posted for this fix. the cgroup subsystem has an early_init flag thats > > supposed to prevent the initialization of cgroups that don't need initialization > > until later (like via module_init() calls). > > Here is the backtrace that I get and below a patch that fixes it: > > [ 0.010958] Initializing cgroup subsys net_prio > [ 0.011040] BUG: unable to handle kernel NULL pointer dereference at 0000000000000828 > [ 0.011998] IP: [<ffffffff814202c8>] update_netdev_tables+0x68/0xe0 > [ 0.011998] PGD 0 > [ 0.011998] Oops: 0000 [#1] SMP > [ 0.011998] CPU 0 > [ 0.011998] Modules linked in: > [ 0.011998] > [ 0.011998] Pid: 0, comm: swapper/0 Not tainted 3.5.0-rc7-mdrlinux+ #10 Bochs Bochs > [ 0.011998] RIP: 0010:[<ffffffff814202c8>] [<ffffffff814202c8>] update_netdev_tables+0x68/0xe0 > [ 0.011998] RSP: 0000:ffffffff81a01e68 EFLAGS: 00010246 > [ 0.011998] RAX: 0000000000000000 RBX: fffffffffffffed0 RCX: 0000000000000000 > [ 0.011998] RDX: 0000000000000006 RSI: 2222222222222222 RDI: 2222222222222222 > [ 0.011998] RBP: ffffffff81a01e88 R08: 2222222222222222 R09: 2222222222222222 > [ 0.011998] R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000001 > [ 0.011998] R13: 0000000000000000 R14: ffff88007ff608c0 R15: 00000000000143d0 > [ 0.011998] FS: 0000000000000000(0000) GS:ffff88007fc00000(0000) knlGS:0000000000000000 > [ 0.011998] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b > [ 0.011998] CR2: 0000000000000828 CR3: 0000000001a0b000 CR4: 00000000000006b0 > [ 0.011998] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > [ 0.011998] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 > [ 0.011998] Process swapper/0 (pid: 0, threadinfo ffffffff81a00000, task ffffffff81a13420) > [ 0.011998] Stack: > [ 0.011998] ffffffff81a88020 0000000000000000 ffff88007d3a38f0 fffffffffffffff4 > [ 0.011998] ffffffff81a01ec8 ffffffff814203cd ffff88007ff608c0 ffffffff817d8e9a > [ 0.011998] ffffffff81a88cd8 ffffffff81a88020 ffffffff81a88020 ffffffff81b010a0 > [ 0.011998] Call Trace: > [ 0.011998] [<ffffffff814203cd>] cgrp_create+0x8d/0xc0 > [ 0.011998] [<ffffffff81ade14a>] cgroup_init_subsys+0x80/0x126 > [ 0.011998] [<ffffffff81ade380>] cgroup_init+0x36/0x117 > [ 0.011998] [<ffffffff81acab71>] start_kernel+0x32e/0x34f > [ 0.011998] [<ffffffff81aca6d5>] ? repair_env_string+0x5a/0x5a > [ 0.011998] [<ffffffff81aca346>] x86_64_start_reservations+0x101/0x105 > [ 0.011998] [<ffffffff81aca120>] ? early_idt_handlers+0x120/0x120 > [ 0.011998] [<ffffffff81aca417>] x86_64_start_kernel+0xcd/0xdc > [ 0.011998] Code: 0f 1f 00 48 8b 83 30 01 00 00 48 8d 98 d0 fe ff ff 48 3d a8 e8 52 82 74 3a e8 25 db c3 ff 85 c0 74 09 80 3d bb 3d 68 00 00 74 40 <48> 8b 83 58 09 00 00 48 85 c0 74 cc 44 3b 60 10 76 c6 44 89 e6 > [ 0.011998] RIP [<ffffffff814202c8>] update_netdev_tables+0x68/0xe0 > [ 0.011998] RSP <ffffffff81a01e68> > [ 0.011998] CR2: 0000000000000828 > [ 0.012009] ---[ end trace a7919e7f17c0a725 ]--- > [ 0.012601] Kernel panic - not syncing: Attempted to kill the idle task! > > The following change simply statically initializes init_net.dev_base_head. I copied and pasted it into the email, so this rendering may not work, but I can send it if this approach looks reasonable. I have verified that it resolves the issue above. > > diff --git a/net/core/dev.c b/net/core/dev.c > index 0f28a9e..db1ba61 100644 > --- a/net/core/dev.c > +++ b/net/core/dev.c > @@ -6283,8 +6283,6 @@ static struct hlist_head *netdev_create_hash(void) > /* Initialize per network namespace state */ > static int __net_init netdev_init(struct net *net) > { > - INIT_LIST_HEAD(&net->dev_base_head); > - if (net != &init_net) INIT_LIST_HEAD(&net->dev_base_head); > net->dev_name_head = netdev_create_hash(); > if (net->dev_name_head == NULL) > goto err_name; > diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c > index dddbacb..42f1e1c 100644 > --- a/net/core/net_namespace.c > +++ b/net/core/net_namespace.c > @@ -27,7 +27,9 @@ static DEFINE_MUTEX(net_mutex); > LIST_HEAD(net_namespace_list); > EXPORT_SYMBOL_GPL(net_namespace_list); > > -struct net init_net; > +struct net init_net = { > + .dev_base_head = LIST_HEAD_INIT(init_net.dev_base_head), > +}; > EXPORT_SYMBOL(init_net); > > #define INITIAL_NET_GEN_PTRS 13 /* +1 for len +2 for rcu_head */ > -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Jul 18, 2012, at 10:55 AM, Eric Dumazet wrote: > On Wed, 2012-07-18 at 17:36 +0000, Rustad, Mark D wrote: >> >> The following change simply statically initializes init_net.dev_base_head. I copied and pasted it into the email, so this rendering may not work, but I can send it if this approach looks reasonable. I have verified that it resolves the issue above. >> >> diff --git a/net/core/dev.c b/net/core/dev.c >> index 0f28a9e..db1ba61 100644 >> --- a/net/core/dev.c >> +++ b/net/core/dev.c >> @@ -6283,8 +6283,6 @@ static struct hlist_head *netdev_create_hash(void) >> /* Initialize per network namespace state */ >> static int __net_init netdev_init(struct net *net) >> { >> - INIT_LIST_HEAD(&net->dev_base_head); >> - > > if (net != &init_net) > INIT_LIST_HEAD(&net->dev_base_head); Ooooh. Good catch. >> net->dev_name_head = netdev_create_hash(); >> if (net->dev_name_head == NULL) >> goto err_name; >> diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c >> index dddbacb..42f1e1c 100644 >> --- a/net/core/net_namespace.c >> +++ b/net/core/net_namespace.c >> @@ -27,7 +27,9 @@ static DEFINE_MUTEX(net_mutex); >> LIST_HEAD(net_namespace_list); >> EXPORT_SYMBOL_GPL(net_namespace_list); >> >> -struct net init_net; >> +struct net init_net = { >> + .dev_base_head = LIST_HEAD_INIT(init_net.dev_base_head), >> +}; >> EXPORT_SYMBOL(init_net); >> >> #define INITIAL_NET_GEN_PTRS 13 /* +1 for len +2 for rcu_head */ If this looks like a good change, I can send the patch. Is there any concern about init_net going from bss to data?
From: "Rustad, Mark D" <mark.d.rustad@intel.com> Date: Wed, 18 Jul 2012 18:31:31 +0000 > If this looks like a good change, I can send the patch. Is there any > concern about init_net going from bss to data? There is no such concern, I like your change a lot. -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/core/dev.c b/net/core/dev.c index 0f28a9e..db1ba61 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6283,8 +6283,6 @@ static struct hlist_head *netdev_create_hash(void) /* Initialize per network namespace state */ static int __net_init netdev_init(struct net *net) { - INIT_LIST_HEAD(&net->dev_base_head); - net->dev_name_head = netdev_create_hash(); if (net->dev_name_head == NULL) goto err_name; diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index dddbacb..42f1e1c 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -27,7 +27,9 @@ static DEFINE_MUTEX(net_mutex); LIST_HEAD(net_namespace_list); EXPORT_SYMBOL_GPL(net_namespace_list); -struct net init_net; +struct net init_net = { + .dev_base_head = LIST_HEAD_INIT(init_net.dev_base_head), +}; EXPORT_SYMBOL(init_net); #define INITIAL_NET_GEN_PTRS 13 /* +1 for len +2 for rcu_head */