Merge branch 'tracing/ftrace' into tracing/core

Merge reason: this mini-topic had outstanding problems that delayed
              its merge, so it does not fast-forward.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

5 files changed, 87 insertions, 35 deletions

diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index a508b9d2adb8..4a13e5a01ce3 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -56,6 +56,13 @@ config CONTEXT_SWITCH_TRACER
         select MARKERS
         bool
 
+# All tracer options should select GENERIC_TRACER. For those options that are
+# enabled by all tracers (context switch and event tracer) they select TRACING.
+# This allows those options to appear when no other tracer is selected. But the
+# options do not appear when something else selects it. We need the two options
+# GENERIC_TRACER and TRACING to avoid circular dependencies to accomplish the
+# hidding of the automatic options options.
+
 config TRACING
         bool
         select DEBUG_FS
@@ -66,6 +73,10 @@ config TRACING
         select BINARY_PRINTF
         select EVENT_TRACING
 
+config GENERIC_TRACER
+        bool
+        select TRACING
+
 #
 # Minimum requirements an architecture has to meet for us to
 # be able to offer generic tracing facilities:
@@ -95,7 +106,7 @@ config FUNCTION_TRACER
         depends on HAVE_FUNCTION_TRACER
         select FRAME_POINTER
         select KALLSYMS
-        select TRACING
+        select GENERIC_TRACER
         select CONTEXT_SWITCH_TRACER
         help
           Enable the kernel to trace every kernel function. This is done
@@ -126,7 +137,7 @@ config IRQSOFF_TRACER
         depends on TRACE_IRQFLAGS_SUPPORT
         depends on GENERIC_TIME
         select TRACE_IRQFLAGS
-        select TRACING
+        select GENERIC_TRACER
         select TRACER_MAX_TRACE
         help
           This option measures the time spent in irqs-off critical
@@ -147,7 +158,7 @@ config PREEMPT_TRACER
         default n
         depends on GENERIC_TIME
         depends on PREEMPT
-        select TRACING
+        select GENERIC_TRACER
         select TRACER_MAX_TRACE
         help
           This option measures the time spent in preemption off critical
@@ -166,7 +177,7 @@ config PREEMPT_TRACER
 config SYSPROF_TRACER
         bool "Sysprof Tracer"
         depends on X86
-        select TRACING
+        select GENERIC_TRACER
         select CONTEXT_SWITCH_TRACER
         help
           This tracer provides the trace needed by the 'Sysprof' userspace
@@ -174,44 +185,33 @@ config SYSPROF_TRACER
 
 config SCHED_TRACER
         bool "Scheduling Latency Tracer"
-        select TRACING
+        select GENERIC_TRACER
         select CONTEXT_SWITCH_TRACER
         select TRACER_MAX_TRACE
         help
           This tracer tracks the latency of the highest priority task
           to be scheduled in, starting from the point it has woken up.
 
-config ENABLE_CONTEXT_SWITCH_TRACER
-        bool "Trace process context switches"
-        select TRACING
-        select CONTEXT_SWITCH_TRACER
-        help
-          This tracer gets called from the context switch and records
-          all switching of tasks.
-
-config ENABLE_EVENT_TRACING
-        bool "Trace various events in the kernel"
+config ENABLE_DEFAULT_TRACERS
+        bool "Trace process context switches and events"
+        depends on !GENERIC_TRACER
         select TRACING
         help
           This tracer hooks to various trace points in the kernel
           allowing the user to pick and choose which trace point they
-          want to trace.
-
-          Note, all tracers enable event tracing. This option is
-          only a convenience to enable event tracing when no other
-          tracers are selected.
+          want to trace. It also includes the sched_switch tracer plugin.
 
 config FTRACE_SYSCALLS
         bool "Trace syscalls"
         depends on HAVE_FTRACE_SYSCALLS
-        select TRACING
+        select GENERIC_TRACER
         select KALLSYMS
         help
           Basic tracer to catch the syscall entry and exit events.
 
 config BOOT_TRACER
         bool "Trace boot initcalls"
-        select TRACING
+        select GENERIC_TRACER
         select CONTEXT_SWITCH_TRACER
         help
           This tracer helps developers to optimize boot times: it records
@@ -228,7 +228,7 @@ config BOOT_TRACER
 
 config TRACE_BRANCH_PROFILING
         bool
-        select TRACING
+        select GENERIC_TRACER
 
 choice
         prompt "Branch Profiling"
@@ -308,7 +308,7 @@ config BRANCH_TRACER
 config POWER_TRACER
         bool "Trace power consumption behavior"
         depends on X86
-        select TRACING
+        select GENERIC_TRACER
         help
           This tracer helps developers to analyze and optimize the kernels
           power management decisions, specifically the C-state and P-state
@@ -342,14 +342,14 @@ config STACK_TRACER
 config HW_BRANCH_TRACER
         depends on HAVE_HW_BRANCH_TRACER
         bool "Trace hw branches"
-        select TRACING
+        select GENERIC_TRACER
         help
           This tracer records all branches on the system in a circular
           buffer giving access to the last N branches for each cpu.
 
 config KMEMTRACE
         bool "Trace SLAB allocations"
-        select TRACING
+        select GENERIC_TRACER
         help
           kmemtrace provides tracing for slab allocator functions, such as
           kmalloc, kfree, kmem_cache_alloc, kmem_cache_free etc.. Collected
@@ -369,7 +369,7 @@ config KMEMTRACE
 
 config WORKQUEUE_TRACER
         bool "Trace workqueues"
-        select TRACING
+        select GENERIC_TRACER
         help
           The workqueue tracer provides some statistical informations
           about each cpu workqueue thread such as the number of the
@@ -385,7 +385,7 @@ config BLK_DEV_IO_TRACE
         select RELAY
         select DEBUG_FS
         select TRACEPOINTS
-        select TRACING
+        select GENERIC_TRACER
         select STACKTRACE
         help
           Say Y here if you want to be able to trace the block layer actions
@@ -446,7 +446,7 @@ config FTRACE_SELFTEST
 
 config FTRACE_STARTUP_TEST
         bool "Perform a startup test on ftrace"
-        depends on TRACING
+        depends on GENERIC_TRACER
         select FTRACE_SELFTEST
         help
           This option performs a series of startup tests on ftrace. On bootup
@@ -457,7 +457,7 @@ config FTRACE_STARTUP_TEST
 config MMIOTRACE
         bool "Memory mapped IO tracing"
         depends on HAVE_MMIOTRACE_SUPPORT && PCI
-        select TRACING
+        select GENERIC_TRACER
         help
           Mmiotrace traces Memory Mapped I/O access and is meant for
           debugging and reverse engineering. It is called from the ioremap
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 140699a9a8a7..d6973dfadb36 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -32,6 +32,7 @@
 #include <trace/events/sched.h>
 
 #include <asm/ftrace.h>
+#include <asm/setup.h>
 
 #include "trace_output.h"
 #include "trace_stat.h"
@@ -598,7 +599,7 @@ function_profile_call(unsigned long ip, unsigned long parent_ip)
         local_irq_save(flags);
 
         stat = &__get_cpu_var(ftrace_profile_stats);
-        if (!stat->hash)
+        if (!stat->hash || !ftrace_profile_enabled)
                 goto out;
 
         rec = ftrace_find_profiled_func(stat, ip);
@@ -629,7 +630,7 @@ static void profile_graph_return(struct ftrace_graph_ret *trace)
 
         local_irq_save(flags);
         stat = &__get_cpu_var(ftrace_profile_stats);
-        if (!stat->hash)
+        if (!stat->hash || !ftrace_profile_enabled)
                 goto out;
 
         calltime = trace->rettime - trace->calltime;
@@ -723,6 +724,10 @@ ftrace_profile_write(struct file *filp, const char __user *ubuf,
                         ftrace_profile_enabled = 1;
                 } else {
                         ftrace_profile_enabled = 0;
+                        /*
+                         * unregister_ftrace_profiler calls stop_machine
+                         * so this acts like an synchronize_sched.
+                         */
                         unregister_ftrace_profiler();
                 }
         }
@@ -2369,6 +2374,45 @@ void ftrace_set_notrace(unsigned char *buf, int len, int reset)
         ftrace_set_regex(buf, len, reset, 0);
 }
 
+/*
+ * command line interface to allow users to set filters on boot up.
+ */
+#define FTRACE_FILTER_SIZE              COMMAND_LINE_SIZE
+static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
+static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
+
+static int __init set_ftrace_notrace(char *str)
+{
+        strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
+        return 1;
+}
+__setup("ftrace_notrace=", set_ftrace_notrace);
+
+static int __init set_ftrace_filter(char *str)
+{
+        strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
+        return 1;
+}
+__setup("ftrace_filter=", set_ftrace_filter);
+
+static void __init set_ftrace_early_filter(char *buf, int enable)
+{
+        char *func;
+
+        while (buf) {
+                func = strsep(&buf, ",");
+                ftrace_set_regex(func, strlen(func), 0, enable);
+        }
+}
+
+static void __init set_ftrace_early_filters(void)
+{
+        if (ftrace_filter_buf[0])
+                set_ftrace_early_filter(ftrace_filter_buf, 1);
+        if (ftrace_notrace_buf[0])
+                set_ftrace_early_filter(ftrace_notrace_buf, 0);
+}
+
 static int
 ftrace_regex_release(struct inode *inode, struct file *file, int enable)
 {
@@ -2829,6 +2873,8 @@ void __init ftrace_init(void)
         if (ret)
                 pr_warning("Failed to register trace ftrace module notifier\n");
 
+        set_ftrace_early_filters();
+
         return;
  failed:
         ftrace_disabled = 1;
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index a3a8a87d7e91..cae34c69752f 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2826,6 +2826,9 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp)
         /* trace pipe does not show start of buffer */
         cpumask_setall(iter->started);
 
+        if (trace_flags & TRACE_ITER_LATENCY_FMT)
+                iter->iter_flags |= TRACE_FILE_LAT_FMT;
+
         iter->cpu_file = cpu_file;
         iter->tr = &global_trace;
         mutex_init(&iter->mutex);
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index a7430b16d243..db6e54bdb596 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -478,12 +478,12 @@ enum {
 
 static int is_string_field(const char *type)
 {
+        if (strstr(type, "__data_loc") && strstr(type, "char"))
+                return FILTER_DYN_STRING;
+
         if (strchr(type, '[') && strstr(type, "char"))
                 return FILTER_STATIC_STRING;
 
-        if (!strcmp(type, "__str_loc"))
-                return FILTER_DYN_STRING;
-
         return 0;
 }
 
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index c12d95db2f56..0fe3b223f7ed 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -17,6 +17,7 @@
 static DECLARE_RWSEM(trace_event_mutex);
 
 DEFINE_PER_CPU(struct trace_seq, ftrace_event_seq);
+EXPORT_PER_CPU_SYMBOL(ftrace_event_seq);
 
 static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly;
 
@@ -250,6 +251,7 @@ ftrace_print_flags_seq(struct trace_seq *p, const char *delim,
 
         return p->buffer;
 }
+EXPORT_SYMBOL(ftrace_print_flags_seq);
 
 const char *
 ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val,
@@ -275,6 +277,7 @@ ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val,
 
         return p->buffer;
 }
+EXPORT_SYMBOL(ftrace_print_symbols_seq);
 
 #ifdef CONFIG_KRETPROBES
 static inline const char *kretprobed(const char *name)