+++ This bug was initially created as a clone of Bug #16323 +++ Subject : 2.6.35-rc3-git4 - kernel/sched.c:616 invoked rcu_dereference_check() without protection! Submitter : Miles Lane <miles.lane@gmail.com> Date : 2010-07-01 12:21 Message-ID : AANLkTini6hz2LFeZi8CMUmY3xw1MU7NxmyesuxZ4oCdo@mail.gmail.com References : http://marc.info/?l=linux-kernel&m=127798693125541&w=2 This entry is being used for tracking a regression from 2.6.34. Please don't close it until the problem is fixed in the mainline.
Supposedly fixed by commit dc61b1d6 ("sched: Fix PROVE_RCU vs cpu_cgroup"), but apparently not: [ 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
[ 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: [<ffffffff81052b6b>] cpu_maps_update_begin+0x17/0x19 #1: (cpu_hotplug.lock){+.+.+.}, at: [<ffffffff81052a7e>] cpu_hotplug_begin+0x2c/0x53 #2: (&rq->lock){-.....}, at: [<ffffffff81491b85>] init_idle+0x30/0x131 stack backtrace: Pid: 1, comm: swapper Not tainted 2.6.35.2-7.rc1.fc14.x86_64 #1 Call Trace: [<ffffffff8107bca2>] lockdep_rcu_dereference+0xaa/0xb3 [<ffffffff8103fdc5>] task_group+0x80/0x8f [<ffffffff8103fdeb>] set_task_rq+0x17/0x73 [<ffffffff81491c3f>] init_idle+0xea/0x131 [<ffffffff8149200f>] fork_idle+0x92/0xa3 [<ffffffff8107e788>] ? mark_held_locks+0x50/0x72 [<ffffffff8148fab0>] do_fork_idle+0x1c/0x2d [<ffffffff8148fbf8>] do_boot_cpu+0x137/0x9b1 [<ffffffff8148fa94>] ? do_fork_idle+0x0/0x2d [<ffffffff81490c96>] native_cpu_up+0x100/0x1c2 [<ffffffff814920e8>] _cpu_up+0x9d/0xf9 [<ffffffff81492217>] cpu_up+0xd3/0xe5 [<ffffffff81d78d86>] kernel_init+0x105/0x2c9 [<ffffffff8100aae4>] kernel_thread_helper+0x4/0x10 [<ffffffff814993d0>] ? restore_args+0x0/0x30 [<ffffffff81d78c81>] ? kernel_init+0x0/0x2c9 [<ffffffff8100aae0>] ? kernel_thread_helper+0x0/0x10
[ 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: [<ffffffff81052b6b>] cpu_maps_update_begin+0x17/0x19 #1: (cpu_hotplug.lock){+.+.+.}, at: [<ffffffff81052a7e>] cpu_hotplug_begin+0x2c/0x53 #2: (&rq->lock){-.....}, at: [<ffffffff81491bc5>] init_idle+0x30/0x131 stack backtrace: Pid: 1, comm: swapper Not tainted 2.6.35.2-8.fc14.x86_64 #1 Call Trace: [<ffffffff8107bca2>] lockdep_rcu_dereference+0xaa/0xb3 [<ffffffff8103fdc5>] task_group+0x80/0x8f [<ffffffff8103fdeb>] set_task_rq+0x17/0x73 [<ffffffff81491c7f>] init_idle+0xea/0x131 [<ffffffff8149204f>] fork_idle+0x92/0xa3 [<ffffffff8107e788>] ? mark_held_locks+0x50/0x72 [<ffffffff8148faf0>] do_fork_idle+0x1c/0x2d [<ffffffff8148fc38>] do_boot_cpu+0x137/0x9b1 [<ffffffff8148fad4>] ? do_fork_idle+0x0/0x2d [<ffffffff81490cd6>] native_cpu_up+0x100/0x1c2 [<ffffffff81492128>] _cpu_up+0x9d/0xf9 [<ffffffff81492257>] cpu_up+0xd3/0xe5 [<ffffffff81d78d86>] kernel_init+0x105/0x2c9 [<ffffffff8100aae4>] kernel_thread_helper+0x4/0x10 [<ffffffff81499410>] ? restore_args+0x0/0x30 [<ffffffff81d78c81>] ? kernel_init+0x0/0x2c9 [<ffffffff8100aae0>] ? kernel_thread_helper+0x0/0x10
*** This bug has been marked as a duplicate of bug 16323 ***