Tetsuo Handa 4221a9918e Add RCU check for find_task_by_vpid(). ... find_task_by_vpid() says "Must be called under rcu_read_lock().". But due to commit 3120438 "rcu: Disable lockdep checking in RCU list-traversal primitives", we are currently unable to catch "find_task_by_vpid() with tasklist_lock held but RCU lock not held" errors due to the RCU-lockdep checks being suppressed in the RCU variants of the struct list_head traversals. This commit therefore places an explicit check for being in an RCU read-side critical section in find_task_by_pid_ns(). =================================================== [ INFO: suspicious rcu_dereference_check() usage. ] --------------------------------------------------- kernel/pid.c:386 invoked rcu_dereference_check() without protection! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 1 1 lock held by rc.sysinit/1102: #0: (tasklist_lock){.+.+..}, at: [<c1048340>] sys_setpgid+0x40/0x160 stack backtrace: Pid: 1102, comm: rc.sysinit Not tainted 2.6.35-rc3-dirty #1 Call Trace: [<c105e714>] lockdep_rcu_dereference+0x94/0xb0 [<c104b4cd>] find_task_by_pid_ns+0x6d/0x70 [<c104b4e8>] find_task_by_vpid+0x18/0x20 [<c1048347>] sys_setpgid+0x47/0x160 [<c1002b50>] sysenter_do_call+0x12/0x36 Commit updated to use a new rcu_lockdep_assert() exported API rather than the old internal __do_rcu_dereference(). Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>		2010-08-19 17:18:02 -07:00
..
acpi	Merge branch 'linus' into release	2010-08-15 01:06:31 -04:00
asm-generic	Fix the declaration of sys_execve() in asm-generic/syscalls.h	2010-08-18 12:12:38 -07:00
crypto
drm	include: replace unifdef-y with header-y	2010-08-14 22:26:51 +02:00
keys
linux	Add RCU check for find_task_by_vpid().	2010-08-19 17:18:02 -07:00
math-emu
media
mtd
net	net/netfilter: __rcu annotations	2010-08-19 17:18:01 -07:00
pcmcia
rdma
rxrpc
scsi	scsi: use __uX types for headers exported to user space	2010-08-11 08:59:01 -07:00
sound	ALSA: emu10k1 - delay the PCM interrupts (add pcm_irq_delay parameter)	2010-08-18 15:10:59 +02:00
trace	Merge branch 'for-2.6.36' of git://git.kernel.dk/linux-2.6-block	2010-08-10 15:22:42 -07:00
video	include: replace unifdef-y with header-y	2010-08-14 22:26:51 +02:00
xen	Merge branch 'stable/xen-swiotlb-0.8.6' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen	2010-08-12 09:09:41 -07:00
Kbuild