Bug 16323 - 2.6.35-rc3-git4 - kernel/sched.c:616 invoked rcu_dereference_check() without protection!
Summary: 2.6.35-rc3-git4 - kernel/sched.c:616 invoked rcu_dereference_check() without ...
Alias: None
Product: Platform Specific/Hardware
Classification: Unclassified
Component: x86-64 (show other bugs)
Hardware: All Linux
: P1 normal
Assignee: platform_x86_64@kernel-bugs.osdl.org
: 16546 (view as bug list)
Depends on:
Blocks: 16055
  Show dependency tree
Reported: 2010-07-01 18:16 UTC by Maciej Rutecki
Modified: 2010-09-09 18:53 UTC (History)
7 users (show)

See Also:
Kernel Version: 2.6.35-rc3-git4
Regression: Yes
Bisected commit-id:


Description Maciej Rutecki 2010-07-01 18:16:49 UTC
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.
Comment 1 Rafael J. Wysocki 2010-07-09 21:19:02 UTC
Fixed by by commit dc61b1d6 ("sched: Fix PROVE_RCU vs cpu_cgroup").
Comment 2 Chuck Ebbert 2010-08-09 05:19:36 UTC
This bug is not fixed, but I can't reopen it.

[ 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>]
 #1:  (cpu_hotplug.lock){+.+.+.}, at: [<ffffffff81052a5e>]
 #2:  (&rq->lock){-.....}, at: [<ffffffff814919c9>] init_idle+0x30/0x131

stack backtrace:
Pid: 1, comm: swapper Not tainted #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
Comment 3 Chuck Ebbert 2010-08-19 07:14:31 UTC
*** Bug 16546 has been marked as a duplicate of this bug. ***
Comment 4 Florian Mickler 2010-09-08 08:12:38 UTC
Is this still a problem in current mainline kernel?
Comment 5 Miles Lane 2010-09-09 16:47:59 UTC
This is fixed, as far as I can tell.
Comment 6 Florian Mickler 2010-09-09 18:53:24 UTC
Another one bites the dust.

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