Srivatsa S. Bhat b11e3d782b x86, mce: Fix rcu splat in drain_mce_log_buffer() ... While booting, the following message is seen: [ 21.665087] =============================== [ 21.669439] [ INFO: suspicious RCU usage. ] [ 21.673798] 3.2.0-0.0.0.28.36b5ec9-default #2 Not tainted [ 21.681353] ------------------------------- [ 21.685864] arch/x86/kernel/cpu/mcheck/mce.c:194 suspicious rcu_dereference_index_check() usage! [ 21.695013] [ 21.695014] other info that might help us debug this: [ 21.695016] [ 21.703488] [ 21.703489] rcu_scheduler_active = 1, debug_locks = 1 [ 21.710426] 3 locks held by modprobe/2139: [ 21.714754] #0: (&__lockdep_no_validate__){......}, at: [<ffffffff8133afd3>] __driver_attach+0x53/0xa0 [ 21.725020] #1: [ 21.725323] ioatdma: Intel(R) QuickData Technology Driver 4.00 [ 21.733206] (&__lockdep_no_validate__){......}, at: [<ffffffff8133afe1>] __driver_attach+0x61/0xa0 [ 21.743015] #2: (i7core_edac_lock){+.+.+.}, at: [<ffffffffa01cfa5f>] i7core_probe+0x1f/0x5c0 [i7core_edac] [ 21.753708] [ 21.753709] stack backtrace: [ 21.758429] Pid: 2139, comm: modprobe Not tainted 3.2.0-0.0.0.28.36b5ec9-default #2 [ 21.768253] Call Trace: [ 21.770838] [<ffffffff810977cd>] lockdep_rcu_suspicious+0xcd/0x100 [ 21.777366] [<ffffffff8101aa41>] drain_mcelog_buffer+0x191/0x1b0 [ 21.783715] [<ffffffff8101aa78>] mce_register_decode_chain+0x18/0x20 [ 21.790430] [<ffffffffa01cf8db>] i7core_register_mci+0x2fb/0x3e4 [i7core_edac] [ 21.798003] [<ffffffffa01cfb14>] i7core_probe+0xd4/0x5c0 [i7core_edac] [ 21.804809] [<ffffffff8129566b>] local_pci_probe+0x5b/0xe0 [ 21.810631] [<ffffffff812957c9>] __pci_device_probe+0xd9/0xe0 [ 21.816650] [<ffffffff813362e4>] ? get_device+0x14/0x20 [ 21.822178] [<ffffffff81296916>] pci_device_probe+0x36/0x60 [ 21.828061] [<ffffffff8133ac8a>] really_probe+0x7a/0x2b0 [ 21.833676] [<ffffffff8133af23>] driver_probe_device+0x63/0xc0 [ 21.839868] [<ffffffff8133b01b>] __driver_attach+0x9b/0xa0 [ 21.845718] [<ffffffff8133af80>] ? driver_probe_device+0xc0/0xc0 [ 21.852027] [<ffffffff81339168>] bus_for_each_dev+0x68/0x90 [ 21.857876] [<ffffffff8133aa3c>] driver_attach+0x1c/0x20 [ 21.863462] [<ffffffff8133a64d>] bus_add_driver+0x16d/0x2b0 [ 21.869377] [<ffffffff8133b6dc>] driver_register+0x7c/0x160 [ 21.875220] [<ffffffff81296bda>] __pci_register_driver+0x6a/0xf0 [ 21.881494] [<ffffffffa01fe000>] ? 0xffffffffa01fdfff [ 21.886846] [<ffffffffa01fe047>] i7core_init+0x47/0x1000 [i7core_edac] [ 21.893737] [<ffffffff810001ce>] do_one_initcall+0x3e/0x180 [ 21.899670] [<ffffffff810a9b95>] sys_init_module+0xc5/0x220 [ 21.905542] [<ffffffff8149bc39>] system_call_fastpath+0x16/0x1b Fix this by using ACCESS_ONCE() instead of rcu_dereference_check_mce() over mcelog.next. Since the access to each entry is controlled by the ->finished field, ACCESS_ONCE() should work just fine. An rcu_dereference is unnecessary here. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Suggested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>		2012-03-07 11:44:29 +01:00
..
alpha	Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci	2012-01-11 18:50:26 -08:00
arm	Another set of arm-soc bug fixes on top of v3.3-rc5. The few larger	2012-02-29 11:24:39 -08:00
avr32	avr32: select generic atomic64_t support	2012-02-03 16:16:40 -08:00
blackfin	Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci	2012-01-11 18:50:26 -08:00
c6x	Kbuild: Use dtc's -d (dependency) option	2012-02-14 21:14:44 -05:00
cris	lib: use generic pci_iomap on all architectures	2012-01-10 18:04:27 -08:00
frv	Merge branch 'for-next' of git://git.infradead.org/users/dhowells/linux-headers	2012-01-14 18:03:30 -08:00
h8300	Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci	2012-01-11 18:50:26 -08:00
hexagon
ia64	Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux	2012-01-18 15:51:48 -08:00
m32r	Merge branch 'for-next' of git://git.infradead.org/users/dhowells/linux-headers	2012-01-14 18:03:30 -08:00
m68k	m68k: Do not set global share for non-kernel shared pages	2012-02-07 11:25:57 +10:00
microblaze	Revert "microblaze: Add topology init"	2012-01-31 09:06:52 +01:00
mips	mips: use the the PCI controller's io_map_base	2012-01-31 23:20:30 +02:00
mn10300	Merge branch 'for-next' of git://git.infradead.org/users/dhowells/linux-headers	2012-01-14 18:03:30 -08:00
openrisc	openrisc: Fix up audit_syscall_[entry|exit]() usage	2012-02-17 09:53:12 +01:00
parisc	[PARISC] don't unconditionally override CROSS_COMPILE for 64 bit.	2012-02-28 09:39:28 -06:00
powerpc	powerpc: Fix various issues with return to userspace	2012-02-22 16:48:53 +11:00
s390	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux	2012-03-01 18:22:55 -08:00
score	score: fix off-by-one index into syscall table	2012-01-23 08:38:49 -08:00
sh	SuperH fixes for 3.3-rc5	2012-02-24 08:56:51 -08:00
sparc	lib: Fix multiple definitions of clz_tab	2012-02-02 10:34:23 +11:00
tile	Merge branch 'for-next' of git://git.infradead.org/users/dhowells/linux-headers	2012-01-14 18:03:30 -08:00
um	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit	2012-01-17 16:41:31 -08:00
unicore32	Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci	2012-01-11 18:50:26 -08:00
x86	x86, mce: Fix rcu splat in drain_mce_log_buffer()	2012-03-07 11:44:29 +01:00
xtensa	xtensa: fix memscan()	2012-02-03 16:16:40 -08:00
.gitignore
Kconfig	mm,x86,um: move CMPXCHG_DOUBLE config option	2012-01-12 20:13:03 -08:00