Merge branch 'tip/tracing/core' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/core

9 files changed, 38 insertions, 20 deletions

diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 309689245431..605ef196fdd6 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -30,14 +30,32 @@
 
 #ifdef CONFIG_DYNAMIC_FTRACE
 
+/*
+ * modifying_code is set to notify NMIs that they need to use
+ * memory barriers when entering or exiting. But we don't want
+ * to burden NMIs with unnecessary memory barriers when code
+ * modification is not being done (which is most of the time).
+ *
+ * A mutex is already held when ftrace_arch_code_modify_prepare
+ * and post_process are called. No locks need to be taken here.
+ *
+ * Stop machine will make sure currently running NMIs are done
+ * and new NMIs will see the updated variable before we need
+ * to worry about NMIs doing memory barriers.
+ */
+static int modifying_code __read_mostly;
+static DEFINE_PER_CPU(int, save_modifying_code);
+
 int ftrace_arch_code_modify_prepare(void)
 {
         set_kernel_text_rw();
+        modifying_code = 1;
         return 0;
 }
 
 int ftrace_arch_code_modify_post_process(void)
 {
+        modifying_code = 0;
         set_kernel_text_ro();
         return 0;
 }
@@ -149,6 +167,11 @@ static void ftrace_mod_code(void)
 
 void ftrace_nmi_enter(void)
 {
+        __get_cpu_var(save_modifying_code) = modifying_code;
+
+        if (!__get_cpu_var(save_modifying_code))
+                return;
+
         if (atomic_inc_return(&nmi_running) & MOD_CODE_WRITE_FLAG) {
                 smp_rmb();
                 ftrace_mod_code();
@@ -160,6 +183,9 @@ void ftrace_nmi_enter(void)
 
 void ftrace_nmi_exit(void)
 {
+        if (!__get_cpu_var(save_modifying_code))
+                return;
+
         /* Finish all executions before clearing nmi_running */
         smp_mb();
         atomic_dec(&nmi_running);
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 7b219696ad24..91bd7d78a07d 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -132,7 +132,8 @@ struct perf_event_attr;
 
 #define SYSCALL_TRACE_ENTER_EVENT(sname)                                \
         static const struct syscall_metadata __syscall_meta_##sname;    \
-        static struct ftrace_event_call event_enter_##sname;            \
+        static struct ftrace_event_call                                 \
+        __attribute__((__aligned__(4))) event_enter_##sname;            \
         static struct trace_event enter_syscall_print_##sname = {       \
                 .trace                  = print_syscall_enter,          \
         };                                                              \
@@ -153,7 +154,8 @@ struct perf_event_attr;
 
 #define SYSCALL_TRACE_EXIT_EVENT(sname)                                 \
         static const struct syscall_metadata __syscall_meta_##sname;    \
-        static struct ftrace_event_call event_exit_##sname;             \
+        static struct ftrace_event_call                                 \
+        __attribute__((__aligned__(4))) event_exit_##sname;             \
         static struct trace_event exit_syscall_print_##sname = {        \
                 .trace                  = print_syscall_exit,           \
         };                                                              \
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 09fd9afc0859..f23a0ca6910a 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -65,7 +65,8 @@
         };
 #undef DEFINE_EVENT
 #define DEFINE_EVENT(template, name, proto, args)       \
-        static struct ftrace_event_call event_##name
+        static struct ftrace_event_call                 \
+        __attribute__((__aligned__(4))) event_##name
 
 #undef DEFINE_EVENT_PRINT
 #define DEFINE_EVENT_PRINT(template, name, proto, args, print)  \
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 60e2ce0181ee..e6b99b8c3d35 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -328,15 +328,6 @@ config BRANCH_TRACER
 
           Say N if unsure.
 
-config POWER_TRACER
-        bool "Trace power consumption behavior"
-        depends on X86
-        select GENERIC_TRACER
-        help
-          This tracer helps developers to analyze and optimize the kernel's
-          power management decisions, specifically the C-state and P-state
-          behavior.
-
 config KSYM_TRACER
         bool "Trace read and write access on kernel memory locations"
         depends on HAVE_HW_BREAKPOINT
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index b477fce41edf..fd05bcaf91b0 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -792,7 +792,8 @@ extern const char *__stop___trace_bprintk_fmt[];
 
 #undef FTRACE_ENTRY
 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print)             \
-        extern struct ftrace_event_call event_##call;
+        extern struct ftrace_event_call                                 \
+        __attribute__((__aligned__(4))) event_##call;
 #undef FTRACE_ENTRY_DUP
 #define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print)         \
         FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index c2a3077b7353..3f972ad98d04 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -60,10 +60,8 @@ int trace_define_field(struct ftrace_event_call *call, const char *type,
         return 0;
 
 err:
-        if (field) {
+        if (field)
                 kfree(field->name);
-                kfree(field->type);
-        }
         kfree(field);
 
         return -ENOMEM;
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 616b135c9eb9..112561df2a0a 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -855,7 +855,6 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
         int i;
 
         if (data) {
-                int cpu = iter->cpu;
                 int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth);
 
                 /*
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 53f748b64ef3..465b36bef4ca 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -651,12 +651,12 @@ static int create_trace_probe(int argc, char **argv)
                         event = strchr(group, '/') + 1;
                         event[-1] = '\0';
                         if (strlen(group) == 0) {
-                                pr_info("Group name is not specifiled\n");
+                                pr_info("Group name is not specified\n");
                                 return -EINVAL;
                         }
                 }
                 if (strlen(event) == 0) {
-                        pr_info("Event name is not specifiled\n");
+                        pr_info("Event name is not specified\n");
                         return -EINVAL;
                 }
         }
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 49cea70fbf6d..8cdda95da81a 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -603,7 +603,7 @@ int prof_sysexit_enable(struct ftrace_event_call *call)
                 ret = register_trace_sys_exit(prof_syscall_exit);
         if (ret) {
                 pr_info("event trace: Could not activate"
-                                "syscall entry trace point");
+                                "syscall exit trace point");
         } else {
                 set_bit(num, enabled_prof_exit_syscalls);
                 sys_prof_refcount_exit++;