linux/arch
Wanpeng Li b0f48706a1 x86/apic: Order irq_enter/exit() calls correctly vs. ack_APIC_irq()
===============================
[ INFO: suspicious RCU usage. ]
4.8.0-rc6+ #5 Not tainted
-------------------------------
./arch/x86/include/asm/msr-trace.h:47 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

RCU used illegally from idle CPU!
rcu_scheduler_active = 1, debug_locks = 0
RCU used illegally from extended quiescent state!
no locks held by swapper/2/0.

stack backtrace:
CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.8.0-rc6+ #5
Hardware name: Dell Inc. OptiPlex 7020/0F5C5X, BIOS A03 01/08/2015
 0000000000000000 ffff8d1bd6003f10 ffffffff94446949 ffff8d1bd4a68000
 0000000000000001 ffff8d1bd6003f40 ffffffff940e9247 ffff8d1bbdfcf3d0
 000000000000080b 0000000000000000 0000000000000000 ffff8d1bd6003f70
Call Trace:
 <IRQ>  [<ffffffff94446949>] dump_stack+0x99/0xd0
 [<ffffffff940e9247>] lockdep_rcu_suspicious+0xe7/0x120
 [<ffffffff9448e0d5>] do_trace_write_msr+0x135/0x140
 [<ffffffff9406e750>] native_write_msr+0x20/0x30
 [<ffffffff9406503d>] native_apic_msr_eoi_write+0x1d/0x30
 [<ffffffff9405b17e>] smp_trace_call_function_interrupt+0x1e/0x270
 [<ffffffff948cb1d6>] trace_call_function_interrupt+0x96/0xa0
 <EOI>  [<ffffffff947200f4>] ? cpuidle_enter_state+0xe4/0x360
 [<ffffffff947200df>] ? cpuidle_enter_state+0xcf/0x360
 [<ffffffff947203a7>] cpuidle_enter+0x17/0x20
 [<ffffffff940df008>] cpu_startup_entry+0x338/0x4d0
 [<ffffffff9405bfc4>] start_secondary+0x154/0x180

This can be reproduced readily by running ftrace test case of kselftest.

Move the irq_enter() call before ack_APIC_irq(), because irq_enter() tells
the RCU susbstems to end the extended quiescent state, so that the
following trace call in ack_APIC_irq() works correctly. The same applies to
exiting_ack_irq() which calls ack_APIC_irq() after irq_exit().

[ tglx: Massaged changelog ]

Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wanpeng Li <wanpeng.li@hotmail.com>
Link: http://lkml.kernel.org/r/1474198491-3738-1-git-send-email-wanpeng.li@hotmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-09-20 00:31:19 +02:00
..
alpha RTC for 4.8 2016-08-05 09:48:22 -04:00
arc dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
arm KVM locks kvm_device list to prevent corruption on device creation. 2016-08-13 10:11:14 -07:00
arm64 arm64 fixes: 2016-08-13 19:29:46 -07:00
avr32 dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
blackfin dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
c6x dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
cris dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
frv RTC for 4.8 2016-08-05 09:48:22 -04:00
h8300 h8300: Add missing include file to asm/io.h 2016-08-13 08:53:56 -07:00
hexagon dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
ia64 Implements HARDENED_USERCOPY verification of copy_to_user/copy_from_user 2016-08-08 14:48:14 -07:00
m32r mm: do not pass mm_struct into handle_mm_fault 2016-07-26 16:19:19 -07:00
m68k RTC for 4.8 2016-08-05 09:48:22 -04:00
metag metag: Drop show_mem() from mem_init() 2016-08-09 13:41:30 +01:00
microblaze dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
mips MIPS: KVM: Propagate kseg0/mapped tlb fault errors 2016-08-12 12:01:30 +02:00
mn10300 RTC for 4.8 2016-08-05 09:48:22 -04:00
nios2 dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
openrisc dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
parisc RTC for 4.8 2016-08-05 09:48:22 -04:00
powerpc KVM locks kvm_device list to prevent corruption on device creation. 2016-08-13 10:11:14 -07:00
s390 KVM locks kvm_device list to prevent corruption on device creation. 2016-08-13 10:11:14 -07:00
score treewide: replace obsolete _refok by __ref 2016-08-02 17:31:41 -04:00
sh These changes improve device tree support (including builtin DTB), add 2016-08-06 09:00:05 -04:00
sparc Implements HARDENED_USERCOPY verification of copy_to_user/copy_from_user 2016-08-08 14:48:14 -07:00
tile tile: support static_key usage in non-module __exit sections 2016-08-04 08:50:07 -04:00
um Merge branch 'for-linus-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml 2016-08-04 19:37:59 -04:00
unicore32 unicore32: mm: Add missing parameter to arch_vma_access_permitted 2016-08-13 08:53:18 -07:00
x86 x86/apic: Order irq_enter/exit() calls correctly vs. ack_APIC_irq() 2016-09-20 00:31:19 +02:00
xtensa dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
.gitignore
Kconfig Implements HARDENED_USERCOPY verification of copy_to_user/copy_from_user 2016-08-08 14:48:14 -07:00