Messages in this thread |  | | | Date | Wed, 04 Aug 2010 14:56:00 +0400 | | From | Vladislav Bolkhovitin <> | | Subject | 2.6.35: suspicious rcu_dereference_check() usage |
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Hello,
Today I gave a first try to 2.6.35 and it immediately produced:
Aug 4 15:12:09 tgt kernel: [ 183.799040] =================================================== Aug 4 15:12:09 tgt kernel: [ 183.799158] [ INFO: suspicious rcu_dereference_check() usage. ] Aug 4 15:12:09 tgt kernel: [ 183.799158] --------------------------------------------------- Aug 4 15:12:09 tgt kernel: [ 183.799158] kernel/exit.c:1387 invoked rcu_dereference_check() without protection! Aug 4 15:12:09 tgt kernel: [ 183.799158] Aug 4 15:12:09 tgt kernel: [ 183.799158] other info that might help us debug this: Aug 4 15:12:09 tgt kernel: [ 183.799158] Aug 4 15:12:09 tgt kernel: [ 183.799158] Aug 4 15:12:09 tgt kernel: [ 183.799158] rcu_scheduler_active = 1, debug_locks = 1 Aug 4 15:12:09 tgt kernel: [ 183.799158] 2 locks held by mc/3751: Aug 4 15:12:09 tgt kernel: [ 183.799158] #0: (tasklist_lock){.+.+..}, at: [<7813d277>] do_wait+0xa1/0x24f Aug 4 15:12:09 tgt kernel: [ 183.799158] #1: (&(&sighand->siglock)->rlock){-.....}, at: [<7813c6eb>] wait_consider_task+0xdd/0xbc8 Aug 4 15:12:09 tgt kernel: [ 183.799158] Aug 4 15:12:09 tgt kernel: [ 183.799158] stack backtrace: Aug 4 15:12:09 tgt kernel: [ 183.799158] Pid: 3751, comm: mc Not tainted 2.6.35-scst-dbg #3 Aug 4 15:12:09 tgt kernel: [ 183.799158] Call Trace: Aug 4 15:12:09 tgt kernel: [ 183.799158] [<784660a3>] ? printk+0x2d/0x32 Aug 4 15:12:09 tgt kernel: [ 183.799158] [<78165d6e>] lockdep_rcu_dereference+0x8e/0x96 Aug 4 15:12:09 tgt kernel: [ 183.799158] [<7813caa3>] wait_consider_task+0x495/0xbc8 Aug 4 15:12:09 tgt kernel: [ 183.799158] [<7846c809>] ? sub_preempt_count+0x9/0xad Aug 4 15:12:09 tgt kernel: [ 183.799158] [<78164056>] ? put_lock_stats+0xd/0x28 Aug 4 15:12:09 tgt kernel: [ 183.799158] [<7813d277>] ? do_wait+0xa1/0x24f Aug 4 15:12:09 tgt kernel: [ 183.799158] [<78469218>] ? _raw_read_lock+0x6b/0x72 Aug 4 15:12:09 tgt kernel: [ 183.799158] [<7813d2ca>] do_wait+0xf4/0x24f Aug 4 15:12:09 tgt kernel: [ 183.799158] [<7813d48d>] sys_wait4+0x68/0xb2 Aug 4 15:12:09 tgt kernel: [ 183.799158] [<7813afbd>] ? child_wait_callback+0x0/0x73 Aug 4 15:12:09 tgt kernel: [ 183.799158] [<7813d503>] sys_waitpid+0x2c/0x2e Aug 4 15:12:09 tgt kernel: [ 183.799158] [<78102d13>] sysenter_do_call+0x12/0x32 I guess, it was just after I started mc.
Vlad
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