Created attachment 437363 [details] dmesg Description of problem: [ INFO: suspicious rcu_dereference_check() usage. ] --------------------------------------------------- kernel/sched.c:616 invoked rcu_dereference_check() without protection! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 3 locks held by swapper/1: #0: (cpu_add_remove_lock){+.+.+.}, at: [<ffffffff81052b4b>] cpu_maps_update_begin+0x17/0x19 #1: (cpu_hotplug.lock){+.+.+.}, at: [<ffffffff81052a5e>] cpu_hotplug_begin+0x2c/0x53 #2: (&rq->lock){-.....}, at: [<ffffffff814919c9>] init_idle+0x30/0x131 stack backtrace: Pid: 1, comm: swapper Not tainted 2.6.35.1-4.rc1.fc14.x86_64 #1 Call Trace: [<ffffffff8107bc7a>] lockdep_rcu_dereference+0xaa/0xb3 [<ffffffff8103fda5>] task_group+0x80/0x8f [<ffffffff8103fdcb>] set_task_rq+0x17/0x73 [<ffffffff81491a83>] init_idle+0xea/0x131 [<ffffffff81491e53>] fork_idle+0x92/0xa3 [<ffffffff8107e760>] ? mark_held_locks+0x50/0x72 [<ffffffff8148f8f9>] do_fork_idle+0x1c/0x2d [<ffffffff8148fa41>] do_boot_cpu+0x137/0x9ac [<ffffffff8148f8dd>] ? do_fork_idle+0x0/0x2d [<ffffffff81490ada>] native_cpu_up+0x100/0x1c2 [<ffffffff81491f2c>] _cpu_up+0x9d/0xf9 [<ffffffff8149205b>] cpu_up+0xd3/0xe5 [<ffffffff81d78d86>] kernel_init+0x105/0x2c9 [<ffffffff8100aae4>] kernel_thread_helper+0x4/0x10 [<ffffffff81499210>] ? restore_args+0x0/0x30 [<ffffffff81d78c81>] ? kernel_init+0x0/0x2c9 [<ffffffff8100aae0>] ? kernel_thread_helper+0x0/0x10 How reproducible: On boot
(In reply to comment #0) > [ INFO: suspicious rcu_dereference_check() usage. ] Seems very similar to bug 610967 from kernel 2.6.35-0.19.rc3.git4.fc14.x86_64
Also: [root@rawhide etc]# uname -r 2.6.35-3.fc14.i686.PAE =================================================== [ INFO: suspicious rcu_dereference_check() usage. ] --------------------------------------------------- include/linux/cgroup.h:542 invoked rcu_dereference_check() without protection! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 1 lock held by swapper/1: #0: (net_mutex){+.+.+.}, at: [<c0747df5>] register_pernet_subsys+0x17/0x34 stack backtrace: Pid: 1, comm: swapper Not tainted 2.6.35-3.fc14.i686.PAE #1 Call Trace: [<c07de9a2>] ? printk+0x25/0x2b [<c04677a5>] lockdep_rcu_dereference+0x7d/0x86 [<c074094a>] sock_update_classid+0x6c/0x8e [<c07409cb>] sk_alloc+0x5f/0x6a [<c0763ce1>] __netlink_create+0x2a/0x90 [<c076558c>] netlink_kernel_create+0x5f/0x14f [<c07548b8>] rtnetlink_net_init+0x23/0x3b [<c0755c6e>] ? rtnetlink_rcv+0x0/0x27 [<c0747be8>] ops_init+0xda/0xe9 [<c0747d28>] register_pernet_operations+0x84/0xee [<c0747e01>] register_pernet_subsys+0x23/0x34 [<c0ab3dda>] rtnetlink_init+0x42/0xe0 [<c0ab4440>] netlink_proto_init+0xee/0x103 [<c0ab4352>] ? netlink_proto_init+0x0/0x103 [<c0403182>] do_one_initcall+0x62/0x170 [<c0a7c9d3>] kernel_init+0x1b9/0x23a [<c0a7c81a>] ? kernel_init+0x0/0x23a [<c0409002>] kernel_thread_helper+0x6/0x10 How reproduce: On boot
*** Bug 624783 has been marked as a duplicate of this bug. ***
I've got this too, when my notebook is booting: NET: Registered protocol family 16 =================================================== [ INFO: suspicious rcu_dereference_check() usage. ] --------------------------------------------------- include/linux/cgroup.h:542 invoked rcu_dereference_check() without protection! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 1 lock held by swapper/1: #0: (net_mutex){+.+.+.}, at: [<c07368f5>] register_pernet_subsys+0x17/0x34 stack backtrace: Pid: 1, comm: swapper Not tainted 2.6.35-0.57.rc6.git1.fc14.i686 #1 Call Trace: [<c07cc316>] ? printk+0x25/0x2f [<c046094d>] lockdep_rcu_dereference+0x7d/0x86 [<c072f46a>] sock_update_classid+0x6c/0x8e [<c072f4eb>] sk_alloc+0x5f/0x6a [<c07527bd>] __netlink_create+0x2a/0x90 [<c0754068>] netlink_kernel_create+0x5f/0x14f [<c0743394>] rtnetlink_net_init+0x23/0x3b [<c074474a>] ? rtnetlink_rcv+0x0/0x27 [<c07366e8>] ops_init+0xda/0xe9 [<c0736828>] register_pernet_operations+0x84/0xee [<c0736901>] register_pernet_subsys+0x23/0x34 [<c0a93d1d>] rtnetlink_init+0x42/0xe0 [<c0a94383>] netlink_proto_init+0xee/0x103 [<c0a94295>] ? netlink_proto_init+0x0/0x103 [<c040126a>] do_one_initcall+0x62/0x170 [<c0a5e9c2>] kernel_init+0x1b9/0x23a [<c0a5e809>] ? kernel_init+0x0/0x23a [<c0403982>] kernel_thread_helper+0x6/0x10 ACPI: bus type pci registered uname -r: 2.6.35-0.57.rc6.git1.fc14.i686 PC: Asus A3l: http://www.smolts.org/client/show/pub_b684b09c-afb6-41d8-95ce-3739173efde5
Does the patch posted to LKML at http://lkml.org/lkml/2010/8/16/258 fix this problem?
------- Comment From Subrata Modak subrata.ibm.com 2010-08-26 07:27 EDT------- Tried Installing the new Fedora14 Alpha on x86_64 with the following kernel command line parameters: title Fedora 14 Alpha X86_64 Installation root (hd0,0) kernel /VMLINUZ-F14-ALPHA-X86_64-INSTALLATION vnc=1 askmethod debug ro root=UUID=a0a6b9e6-0716-4231-b62f-e72966df97c1 rd_NO_LUKS rd_NO_LVM rd_NO_MD rd_NO_DM LANG=en_US.UTF-8 SYSFONT=latarcyrheb-sun16 KEYTABLE=us rhgb quiet console=tty0 console=ttyS0,9600n1 initrd /INITRD.IMG-F14-ALPHA-X86_64-INSTALLATION When the Installation kernel boots, the following backtrace with suspicious rcu_dereference_check() usage info is displayed: kernel/sched.c:616 invoked rcu_dereference_check() without protection! 3 locks held by swapper/1: #0: (cpu_add_remove_lock){+.+.+.}, at: [<ffffffff81052b57>] cpu_maps_update_begin+0x17/0x19 #1: (cpu_hotplug.lock){+.+.+.}, at: [<ffffffff81052a6a>] cpu_hotplug_begin+0x2c/0x53 #2: (&rq->lock){-.....}, at: [<ffffffff814919e9>] init_idle+0x30/0x131 Pid: 1, comm: swapper Not tainted 2.6.35-0.57.rc6.git1.fc14.x86_64 #1 [<ffffffff8107bc56>] lockdep_rcu_dereference+0xaa/0xb3 [<ffffffff8103fceb>] task_group+0x80/0x8f [<ffffffff8103fd11>] set_task_rq+0x17/0x73 [<ffffffff81491aa3>] init_idle+0xea/0x131 [<ffffffff81491e73>] fork_idle+0x92/0xa3 [<ffffffff8107e73c>] ? mark_held_locks+0x50/0x72 [<ffffffff8148f919>] do_fork_idle+0x1c/0x2d [<ffffffff8148fa61>] do_boot_cpu+0x137/0x9ac [<ffffffff8148f8fd>] ? do_fork_idle+0x0/0x2d [<ffffffff81490afa>] native_cpu_up+0x100/0x1c2 [<ffffffff81491f4c>] _cpu_up+0x9d/0xf9 [<ffffffff8149207b>] cpu_up+0xd3/0xe5 [<ffffffff81d78d86>] kernel_init+0x105/0x2c9 [<ffffffff8100aae4>] kernel_thread_helper+0x4/0x10 [<ffffffff81499250>] ? restore_args+0x0/0x30 [<ffffffff81d78c81>] ? kernel_init+0x0/0x2c9 [<ffffffff8100aae0>] ? kernel_thread_helper+0x0/0x10 Please note that this has been reported against stable 2.6.35 kernel boot on a Power system earlier: https://bugzilla.linux.ibm.com/show_bug.cgi?id=66322, And the same has been reported to community earlier: http://marc.info/?l=linux-kernel&m=128073918419530&w=2, Kindly mirror this to Redhat. Regards-- Subrata
Still seeing this on 2.6.35.4-12.fc14.i686.PAE - James
Hi James, care to try the build here: http://koji.fedoraproject.org/koji/taskinfo?taskID=2449680 and let us know if that squelches the warning?
Kyle, NP, build doesn't look done yet though, so will check in a bit later. - James
Kyle, I now receive this; =================================================== [ INFO: suspicious rcu_dereference_check() usage. ] --------------------------------------------------- include/linux/cgroup.h:542 invoked rcu_dereference_check() without protection! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 1 lock held by swapper/1: #0: (net_mutex){+.+.+.}, at: [<c073a049>] register_pernet_subsys+0x17/0x34 stack backtrace: Pid: 1, comm: swapper Not tainted 2.6.35.4-20.fc14.i686 #1 Call Trace: [<c07cfb1c>] ? printk+0x25/0x29 [<c0460b89>] lockdep_rcu_dereference+0x7d/0x86 [<c0732baa>] sock_update_classid+0x6c/0x8e [<c0732c2b>] sk_alloc+0x5f/0x6a [<c0755f4d>] __netlink_create+0x2a/0x90 [<c07577f8>] netlink_kernel_create+0x5f/0x14f [<c0746b00>] rtnetlink_net_init+0x23/0x3b [<c0747eb6>] ? rtnetlink_rcv+0x0/0x27 [<c0739e3c>] ops_init+0xda/0xe9 [<c0739f7c>] register_pernet_operations+0x84/0xee [<c073a055>] register_pernet_subsys+0x23/0x34 [<c0a97e03>] rtnetlink_init+0x42/0xe0 [<c0a98469>] netlink_proto_init+0xee/0x103 [<c0a9837b>] ? netlink_proto_init+0x0/0x103 [<c040126a>] do_one_initcall+0x62/0x170 [<c0a629c2>] kernel_init+0x1b9/0x23a [<c0a62809>] ? kernel_init+0x0/0x23a [<c0403982>] kernel_thread_helper+0x6/0x10
Yes, we will likely continue to receive these for the time being, as it seems most kernel developers do not have both these debugging options, and cgroups enabled. Paul, any ideas about the other tracebacks in this bug report? Thanks! Kyle
(In reply to comment #10) > Kyle, I now receive this; > > =================================================== > [ INFO: suspicious rcu_dereference_check() usage. ] > --------------------------------------------------- > include/linux/cgroup.h:542 invoked rcu_dereference_check() without protection! > See bug 572520 for the cgroup.h version of this bug.
*** Bug 610967 has been marked as a duplicate of this bug. ***
*** Bug 626026 has been marked as a duplicate of this bug. ***
Duping against bug 626026 as it is a F14 blocker. Sorry for the SPAM. *** This bug has been marked as a duplicate of bug 626026 ***