From: Greg Kroah-Hartman Date: Mon, 9 Feb 2015 08:27:20 +0000 (+0800) Subject: 3.18-stable patches X-Git-Tag: v3.10.69~4 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=285a724ea385170b8b50f330ca4e0fb6f573839f;p=thirdparty%2Fkernel%2Fstable-queue.git 3.18-stable patches added patches: tracing-add-condition-check-to-rcu-lockdep-checks.patch x86-tlb-trace-do-not-trace-on-cpu-that-is-offline.patch --- diff --git a/queue-3.18/series b/queue-3.18/series index bd8497de8d1..6c6ef7b8ca5 100644 --- a/queue-3.18/series +++ b/queue-3.18/series @@ -35,3 +35,5 @@ arm-dts-fix-i2s1-i2s2-compatible-for-exynos4-socs.patch x86-microcode-return-error-from-driver-init-code-when-loader-is-disabled.patch smpboot-add-missing-get_online_cpus-in-smpboot_register_percpu_thread.patch hrtimer-fix-incorrect-tai-offset-calculation-for-non-high-res-timer-systems.patch +tracing-add-condition-check-to-rcu-lockdep-checks.patch +x86-tlb-trace-do-not-trace-on-cpu-that-is-offline.patch diff --git a/queue-3.18/tracing-add-condition-check-to-rcu-lockdep-checks.patch b/queue-3.18/tracing-add-condition-check-to-rcu-lockdep-checks.patch new file mode 100644 index 00000000000..e19a170343a --- /dev/null +++ b/queue-3.18/tracing-add-condition-check-to-rcu-lockdep-checks.patch @@ -0,0 +1,48 @@ +From a05d59a5673339ef6936d6940cdf68172ce75b9f Mon Sep 17 00:00:00 2001 +From: "Steven Rostedt (Red Hat)" +Date: Fri, 6 Feb 2015 14:30:50 -0500 +Subject: tracing: Add condition check to RCU lockdep checks + +From: "Steven Rostedt (Red Hat)" + +commit a05d59a5673339ef6936d6940cdf68172ce75b9f upstream. + +The trace_tlb_flush() tracepoint can be called when a CPU is going offline. +When a CPU is offline, RCU is no longer watching that CPU and since the +tracepoint is protected by RCU, it must not be called. To prevent the +tlb_flush tracepoint from being called when the CPU is offline, it was +converted to a TRACE_EVENT_CONDITION where the condition checks if the +CPU is online before calling the tracepoint. + +Unfortunately, this was not enough to stop lockdep from complaining about +it. Even though the RCU protected code of the tracepoint will never be +called, the condition is hidden within the tracepoint, and even though the +condition prevents RCU code from being called, the lockdep checks are +outside the tracepoint (this is to test tracepoints even when they are not +enabled). + +Even though tracepoints should be checked to be RCU safe when they are not +enabled, the condition should still be considered when checking RCU. + +Link: http://lkml.kernel.org/r/CA+icZUUGiGDoL5NU8RuxKzFjoLjEKRtUWx=JB8B9a0EQv-eGzQ@mail.gmail.com + +Fixes: 3a630178fd5f "tracing: generate RCU warnings even when tracepoints are disabled" +Acked-by: Dave Hansen +Reported-by: Sedat Dilek +Tested-by: Sedat Dilek +Signed-off-by: Steven Rostedt +Signed-off-by: Greg Kroah-Hartman + +diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h +index e08e21e5f601..c72851328ca9 100644 +--- a/include/linux/tracepoint.h ++++ b/include/linux/tracepoint.h +@@ -173,7 +173,7 @@ extern void syscall_unregfunc(void); + TP_PROTO(data_proto), \ + TP_ARGS(data_args), \ + TP_CONDITION(cond),,); \ +- if (IS_ENABLED(CONFIG_LOCKDEP)) { \ ++ if (IS_ENABLED(CONFIG_LOCKDEP) && (cond)) { \ + rcu_read_lock_sched_notrace(); \ + rcu_dereference_sched(__tracepoint_##name.funcs);\ + rcu_read_unlock_sched_notrace(); \ diff --git a/queue-3.18/x86-tlb-trace-do-not-trace-on-cpu-that-is-offline.patch b/queue-3.18/x86-tlb-trace-do-not-trace-on-cpu-that-is-offline.patch new file mode 100644 index 00000000000..d2f2e93b254 --- /dev/null +++ b/queue-3.18/x86-tlb-trace-do-not-trace-on-cpu-that-is-offline.patch @@ -0,0 +1,87 @@ +From 6c8465a82a605bc692304bab42703017dcfff013 Mon Sep 17 00:00:00 2001 +From: "Steven Rostedt (Red Hat)" +Date: Fri, 6 Feb 2015 14:18:19 -0500 +Subject: x86/tlb/trace: Do not trace on CPU that is offline + +From: "Steven Rostedt (Red Hat)" + +commit 6c8465a82a605bc692304bab42703017dcfff013 upstream. + +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: + [] dump_stack+0x4c/0x65 + [] lockdep_rcu_suspicious+0xe7/0x120 + [] idle_task_exit+0x205/0x2c0 + [] play_dead_common+0xe/0x50 + [] native_play_dead+0x15/0x140 + [] arch_cpu_idle_dead+0xf/0x20 + [] cpu_startup_entry+0x37e/0x580 + [] 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 + +Fixes: d17d8f9dedb9 "x86/mm: Add tracepoints for TLB flushes" +Reported-by: Sedat Dilek +Tested-by: Sedat Dilek +Suggested-by: Paul E. McKenney +Acked-by: Paul E. McKenney +Acked-by: Dave Hansen +Signed-off-by: Steven Rostedt +Signed-off-by: Greg Kroah-Hartman + +diff --git a/include/trace/events/tlb.h b/include/trace/events/tlb.h +index 13391d288107..0e7635765153 100644 +--- a/include/trace/events/tlb.h ++++ b/include/trace/events/tlb.h +@@ -13,11 +13,13 @@ + { TLB_LOCAL_SHOOTDOWN, "local shootdown" }, \ + { TLB_LOCAL_MM_SHOOTDOWN, "local mm shootdown" } + +-TRACE_EVENT(tlb_flush, ++TRACE_EVENT_CONDITION(tlb_flush, + + TP_PROTO(int reason, unsigned long pages), + TP_ARGS(reason, pages), + ++ TP_CONDITION(cpu_online(smp_processor_id())), ++ + TP_STRUCT__entry( + __field( int, reason) + __field(unsigned long, pages)