Oleg Nesterov a8d4b8345e introduce __fcheck_files() to fix rcu_dereference_check_fdtable(), kill rcu_my_thread_group_empty() ... rcu_dereference_check_fdtable() looks very wrong, 1. rcu_my_thread_group_empty() was added by 844b9a8707 "vfs: fix RCU-lockdep false positive due to /proc" but it doesn't really fix the problem. A CLONE_THREAD (without CLONE_FILES) task can hit the same race with get_files_struct(). And otoh rcu_my_thread_group_empty() can suppress the correct warning if the caller is the CLONE_FILES (without CLONE_THREAD) task. 2. files->count == 1 check is not really right too. Even if this files_struct is not shared it is not safe to access it lockless unless the caller is the owner. Otoh, this check is sub-optimal. files->count == 0 always means it is safe to use it lockless even if files != current->files, but put_files_struct() has to take rcu_read_lock(). See the next patch. This patch removes the buggy checks and turns fcheck_files() into __fcheck_files() which uses rcu_dereference_raw(), the "unshared" callers, fget_light() and fget_raw_light(), can use it to avoid the warning from RCU-lockdep. fcheck_files() is trivially reimplemented as rcu_lockdep_assert() plus __fcheck_files(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>		2014-01-25 03:14:36 -05:00
..
acpi	Merge branches 'acpi-pci-pm' and 'acpi-pci-hotplug'	2013-12-31 22:03:37 +01:00
asm-generic	mm: Fix NULL pointer dereference in madvise(MADV_WILLNEED) support	2013-12-20 12:17:03 -08:00
clocksource
crypto	crypto: scatterwalk - Use sg_chain_ptr on chain entries	2013-12-09 19:58:52 +08:00
drm	drm/radeon: 0x9649 is SUMO2 not SUMO	2013-12-23 10:03:41 -05:00
dt-bindings
keys
kvm
linux	introduce __fcheck_files() to fix rcu_dereference_check_fdtable(), kill rcu_my_thread_group_empty()	2014-01-25 03:14:36 -05:00
math-emu
media	[media] videobuf2: Add support for file access mode flags for DMABUF exporting	2013-12-09 14:50:50 -02:00
memory
misc
net	ipv6: simplify detection of first operational link-local address on interface	2014-01-17 18:10:01 -08:00
pcmcia
ras
rdma	IB/core: const'ify inbuf in struct ib_udata	2013-12-16 10:38:28 -08:00
rxrpc
scsi
sound	ALSA: memalloc.h - fix wrong truncation of dma_addr_t	2013-12-10 15:30:46 +01:00
target	target/file: Update hw_max_sectors based on current block_size	2013-12-19 00:18:54 -08:00
trace
uapi	Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux	2014-01-01 11:36:16 -08:00
video
xen	Bug-fixes:	2013-12-20 09:34:54 -08:00
Kbuild