3.10-stable patches

added patches:
	tracepoints-do-not-trace-when-cpu-is-offline.patch

diff --git a/queue-3.10/series b/queue-3.10/series
new file mode 100644 (file)
index 0000000..b67d82e
--- /dev/null
+++ b/queue-3.10/series
@@ -0,0 +1 @@
+tracepoints-do-not-trace-when-cpu-is-offline.patch

diff --git a/queue-3.10/tracepoints-do-not-trace-when-cpu-is-offline.patch b/queue-3.10/tracepoints-do-not-trace-when-cpu-is-offline.patch
new file mode 100644 (file)
index 0000000..fee89aa
--- /dev/null
+++ b/queue-3.10/tracepoints-do-not-trace-when-cpu-is-offline.patch
@@ -0,0 +1,90 @@
+From f37755490fe9bf76f6ba1d8c6591745d3574a6a6 Mon Sep 17 00:00:00 2001
+From: "Steven Rostedt (Red Hat)" <rostedt@goodmis.org>
+Date: Mon, 15 Feb 2016 12:36:14 -0500
+Subject: tracepoints: Do not trace when cpu is offline
+
+From: Steven Rostedt (Red Hat) <rostedt@goodmis.org>
+
+commit f37755490fe9bf76f6ba1d8c6591745d3574a6a6 upstream.
+
+The tracepoint infrastructure uses RCU sched protection to enable and
+disable tracepoints safely. There are some instances where tracepoints are
+used in infrastructure code (like kfree()) that get called after a CPU is
+going offline, and perhaps when it is coming back online but hasn't been
+registered yet.
+
+This can probuce the following warning:
+
+ [ INFO: suspicious RCU usage. ]
+ 4.4.0-00006-g0fe53e8-dirty #34 Tainted: G S
+ -------------------------------
+ include/trace/events/kmem.h:141 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 = 1
+ no locks held by swapper/8/0.
+
+ stack backtrace:
+  CPU: 8 PID: 0 Comm: swapper/8 Tainted: G S              4.4.0-00006-g0fe53e8-dirty #34
+  Call Trace:
+  [c0000005b76c78d0] [c0000000008b9540] .dump_stack+0x98/0xd4 (unreliable)
+  [c0000005b76c7950] [c00000000010c898] .lockdep_rcu_suspicious+0x108/0x170
+  [c0000005b76c79e0] [c00000000029adc0] .kfree+0x390/0x440
+  [c0000005b76c7a80] [c000000000055f74] .destroy_context+0x44/0x100
+  [c0000005b76c7b00] [c0000000000934a0] .__mmdrop+0x60/0x150
+  [c0000005b76c7b90] [c0000000000e3ff0] .idle_task_exit+0x130/0x140
+  [c0000005b76c7c20] [c000000000075804] .pseries_mach_cpu_die+0x64/0x310
+  [c0000005b76c7cd0] [c000000000043e7c] .cpu_die+0x3c/0x60
+  [c0000005b76c7d40] [c0000000000188d8] .arch_cpu_idle_dead+0x28/0x40
+  [c0000005b76c7db0] [c000000000101e6c] .cpu_startup_entry+0x50c/0x560
+  [c0000005b76c7ed0] [c000000000043bd8] .start_secondary+0x328/0x360
+  [c0000005b76c7f90] [c000000000008a6c] start_secondary_prolog+0x10/0x14
+
+This warning is not a false positive either. RCU is not protecting code that
+is being executed while the CPU is offline.
+
+Instead of playing "whack-a-mole(TM)" and adding conditional statements to
+the tracepoints we find that are used in this instance, simply add a
+cpu_online() test to the tracepoint code where the tracepoint will be
+ignored if the CPU is offline.
+
+Use of raw_smp_processor_id() is fine, as there should never be a case where
+the tracepoint code goes from running on a CPU that is online and suddenly
+gets migrated to a CPU that is offline.
+
+Link: http://lkml.kernel.org/r/1455387773-4245-1-git-send-email-kda@linux-powerpc.org
+
+Reported-by: Denis Kirjanov <kda@linux-powerpc.org>
+Fixes: 97e1c18e8d17b ("tracing: Kernel Tracepoints")
+Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ include/linux/tracepoint.h |    6 ++++++
+ 1 file changed, 6 insertions(+)
+
+--- a/include/linux/tracepoint.h
++++ b/include/linux/tracepoint.h
+@@ -14,8 +14,11 @@
+  * See the file COPYING for more details.
+  */
+ 
++#include <linux/smp.h>
+ #include <linux/errno.h>
+ #include <linux/types.h>
++#include <linux/percpu.h>
++#include <linux/cpumask.h>
+ #include <linux/rcupdate.h>
+ #include <linux/static_key.h>
+ 
+@@ -126,6 +129,9 @@ static inline void tracepoint_synchroniz
+               void *it_func;                                          \
+               void *__data;                                           \
+                                                                       \
++              if (!cpu_online(raw_smp_processor_id()))                \
++                      return;                                         \
++                                                                      \
+               if (!(cond))                                            \
+                       return;                                         \
+               prercu;                                                 \

diff --git a/queue-3.14/series b/queue-3.14/series
new file mode 100644 (file)
index 0000000..b67d82e
--- /dev/null
+++ b/queue-3.14/series
@@ -0,0 +1 @@
+tracepoints-do-not-trace-when-cpu-is-offline.patch