Steven Rostedt (Red Hat) 6c8465a82a x86/tlb/trace: Do not trace on CPU that is offline ... When taking a CPU down for suspend and resume, a tracepoint may be called when the CPU has been designated offline. As tracepoints require RCU for protection, they must not be called if the current CPU is offline. Unfortunately, trace_tlb_flush() is called in this scenario as was noted by LOCKDEP: ... Disabling non-boot CPUs ... intel_pstate CPU 1 exiting =============================== smpboot: CPU 1 didn't die... [ INFO: suspicious RCU usage. ] 3.19.0-rc7-next-20150204.1-iniza-small #1 Not tainted ------------------------------- include/trace/events/tlb.h:35 suspicious rcu_dereference_check() usage! other info that might help us debug this: RCU used illegally from offline CPU! rcu_scheduler_active = 1, debug_locks = 0 no locks held by swapper/1/0. stack backtrace: CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.19.0-rc7-next-20150204.1-iniza-small #1 Hardware name: SAMSUNG ELECTRONICS CO., LTD. 530U3BI/530U4BI/530U4BH/530U3BI/530U4BI/530U4BH, BIOS 13XK 03/28/2013 0000000000000001 ffff88011a44fe18 ffffffff817e370d 0000000000000011 ffff88011a448290 ffff88011a44fe48 ffffffff810d6847 ffff8800c66b9600 0000000000000001 ffff88011a44c000 ffffffff81cb3900 ffff88011a44fe78 Call Trace: [<ffffffff817e370d>] dump_stack+0x4c/0x65 [<ffffffff810d6847>] lockdep_rcu_suspicious+0xe7/0x120 [<ffffffff810b71a5>] idle_task_exit+0x205/0x2c0 [<ffffffff81054c4e>] play_dead_common+0xe/0x50 [<ffffffff81054ca5>] native_play_dead+0x15/0x140 [<ffffffff8102963f>] arch_cpu_idle_dead+0xf/0x20 [<ffffffff810cd89e>] cpu_startup_entry+0x37e/0x580 [<ffffffff81053e20>] start_secondary+0x140/0x150 intel_pstate CPU 2 exiting ... By converting the tlb_flush tracepoint to a TRACE_EVENT_CONDITION where the condition is cpu_online(smp_processor_id()), we can avoid calling RCU protected code when the CPU is offline. Link: http://lkml.kernel.org/r/CA+icZUUGiGDoL5NU8RuxKzFjoLjEKRtUWx=JB8B9a0EQv-eGzQ@mail.gmail.com Cc: stable@vger.kernel.org # 3.17+ Fixes: d17d8f9ded "x86/mm: Add tracepoints for TLB flushes" Reported-by: Sedat Dilek <sedat.dilek@gmail.com> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Suggested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Dave Hansen <dave@sr71.net> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>		2015-02-07 19:34:55 -05:00
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events	x86/tlb/trace: Do not trace on CPU that is offline	2015-02-07 19:34:55 -05:00
define_trace.h	tracing: Add DEFINE_EVENT_FN() macro	2013-06-20 22:24:32 -07:00
ftrace.h	tracing: Fix return value of ftrace_raw_output_prep()	2014-11-19 15:25:48 -05:00
syscall.h	tracing: Fix syscall_*regfunc() vs copy_process() race	2014-06-21 00:15:12 -04:00