5 files changed, 163 insertions, 31 deletions

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 52da2a250795..f83e17a40e8b 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -261,8 +261,10 @@ struct ftrace_probe_ops {
         void                    (*func)(unsigned long ip,
                                         unsigned long parent_ip,
                                         void **data);
-        int                     (*callback)(unsigned long ip, void **data);
-        void                    (*free)(void **data);
+        int                     (*init)(struct ftrace_probe_ops *ops,
+                                        unsigned long ip, void **data);
+        void                    (*free)(struct ftrace_probe_ops *ops,
+                                        unsigned long ip, void **data);
         int                     (*print)(struct seq_file *m,
                                          unsigned long ip,
                                          struct ftrace_probe_ops *ops,
diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index 13a54d0bdfa8..34e00fb49bec 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -8,6 +8,7 @@
 #include <linux/perf_event.h>
 
 struct trace_array;
+struct trace_buffer;
 struct tracer;
 struct dentry;
 
@@ -38,6 +39,12 @@ const char *ftrace_print_symbols_seq_u64(struct trace_seq *p,
 const char *ftrace_print_hex_seq(struct trace_seq *p,
                                  const unsigned char *buf, int len);
 
+struct trace_iterator;
+struct trace_event;
+
+int ftrace_raw_output_prep(struct trace_iterator *iter,
+                           struct trace_event *event);
+
 /*
  * The trace entry - the most basic unit of tracing. This is what
  * is printed in the end as a single line in the trace output, such as:
@@ -61,6 +68,7 @@ struct trace_entry {
 struct trace_iterator {
         struct trace_array      *tr;
         struct tracer           *trace;
+        struct trace_buffer     *trace_buffer;
         void                    *private;
         int                     cpu_file;
         struct mutex            mutex;
@@ -95,8 +103,6 @@ enum trace_iter_flags {
 };
 
 
-struct trace_event;
-
 typedef enum print_line_t (*trace_print_func)(struct trace_iterator *iter,
                                       int flags, struct trace_event *event);
 
@@ -128,6 +134,13 @@ enum print_line_t {
 void tracing_generic_entry_update(struct trace_entry *entry,
                                   unsigned long flags,
                                   int pc);
+struct ftrace_event_file;
+
+struct ring_buffer_event *
+trace_event_buffer_lock_reserve(struct ring_buffer **current_buffer,
+                                struct ftrace_event_file *ftrace_file,
+                                int type, unsigned long len,
+                                unsigned long flags, int pc);
 struct ring_buffer_event *
 trace_current_buffer_lock_reserve(struct ring_buffer **current_buffer,
                                   int type, unsigned long len,
@@ -182,53 +195,49 @@ extern int ftrace_event_reg(struct ftrace_event_call *event,
                             enum trace_reg type, void *data);
 
 enum {
-        TRACE_EVENT_FL_ENABLED_BIT,
         TRACE_EVENT_FL_FILTERED_BIT,
-        TRACE_EVENT_FL_RECORDED_CMD_BIT,
         TRACE_EVENT_FL_CAP_ANY_BIT,
         TRACE_EVENT_FL_NO_SET_FILTER_BIT,
         TRACE_EVENT_FL_IGNORE_ENABLE_BIT,
+        TRACE_EVENT_FL_WAS_ENABLED_BIT,
 };
 
+/*
+ * Event flags:
+ *  FILTERED      - The event has a filter attached
+ *  CAP_ANY       - Any user can enable for perf
+ *  NO_SET_FILTER - Set when filter has error and is to be ignored
+ *  IGNORE_ENABLE - For ftrace internal events, do not enable with debugfs file
+ *  WAS_ENABLED   - Set and stays set when an event was ever enabled
+ *                    (used for module unloading, if a module event is enabled,
+ *                     it is best to clear the buffers that used it).
+ */
 enum {
-        TRACE_EVENT_FL_ENABLED          = (1 << TRACE_EVENT_FL_ENABLED_BIT),
         TRACE_EVENT_FL_FILTERED         = (1 << TRACE_EVENT_FL_FILTERED_BIT),
-        TRACE_EVENT_FL_RECORDED_CMD     = (1 << TRACE_EVENT_FL_RECORDED_CMD_BIT),
         TRACE_EVENT_FL_CAP_ANY          = (1 << TRACE_EVENT_FL_CAP_ANY_BIT),
         TRACE_EVENT_FL_NO_SET_FILTER    = (1 << TRACE_EVENT_FL_NO_SET_FILTER_BIT),
         TRACE_EVENT_FL_IGNORE_ENABLE    = (1 << TRACE_EVENT_FL_IGNORE_ENABLE_BIT),
+        TRACE_EVENT_FL_WAS_ENABLED      = (1 << TRACE_EVENT_FL_WAS_ENABLED_BIT),
 };
 
 struct ftrace_event_call {
         struct list_head        list;
         struct ftrace_event_class *class;
         char                    *name;
-        struct dentry           *dir;
         struct trace_event      event;
         const char              *print_fmt;
         struct event_filter     *filter;
+        struct list_head        *files;
         void                    *mod;
         void                    *data;
-
         /*
-         * 32 bit flags:
-         *   bit 1:             enabled
-         *   bit 2:             filter_active
-         *   bit 3:             enabled cmd record
-         *   bit 4:             allow trace by non root (cap any)
-         *   bit 5:             failed to apply filter
-         *   bit 6:             ftrace internal event (do not enable)
-         *
-         * Changes to flags must hold the event_mutex.
-         *
-         * Note: Reads of flags do not hold the event_mutex since
-         * they occur in critical sections. But the way flags
-         * is currently used, these changes do no affect the code
-         * except that when a change is made, it may have a slight
-         * delay in propagating the changes to other CPUs due to
-         * caching and such.
+         *   bit 0:             filter_active
+         *   bit 1:             allow trace by non root (cap any)
+         *   bit 2:             failed to apply filter
+         *   bit 3:             ftrace internal event (do not enable)
+         *   bit 4:             Event was enabled by module
          */
-        unsigned int            flags;
+        int                     flags; /* static flags of different events */
 
 #ifdef CONFIG_PERF_EVENTS
         int                             perf_refcount;
@@ -236,6 +245,56 @@ struct ftrace_event_call {
 #endif
 };
 
+struct trace_array;
+struct ftrace_subsystem_dir;
+
+enum {
+        FTRACE_EVENT_FL_ENABLED_BIT,
+        FTRACE_EVENT_FL_RECORDED_CMD_BIT,
+        FTRACE_EVENT_FL_SOFT_MODE_BIT,
+        FTRACE_EVENT_FL_SOFT_DISABLED_BIT,
+};
+
+/*
+ * Ftrace event file flags:
+ *  ENABLED       - The event is enabled
+ *  RECORDED_CMD  - The comms should be recorded at sched_switch
+ *  SOFT_MODE     - The event is enabled/disabled by SOFT_DISABLED
+ *  SOFT_DISABLED - When set, do not trace the event (even though its
+ *                   tracepoint may be enabled)
+ */
+enum {
+        FTRACE_EVENT_FL_ENABLED         = (1 << FTRACE_EVENT_FL_ENABLED_BIT),
+        FTRACE_EVENT_FL_RECORDED_CMD    = (1 << FTRACE_EVENT_FL_RECORDED_CMD_BIT),
+        FTRACE_EVENT_FL_SOFT_MODE       = (1 << FTRACE_EVENT_FL_SOFT_MODE_BIT),
+        FTRACE_EVENT_FL_SOFT_DISABLED   = (1 << FTRACE_EVENT_FL_SOFT_DISABLED_BIT),
+};
+
+struct ftrace_event_file {
+        struct list_head                list;
+        struct ftrace_event_call        *event_call;
+        struct dentry                   *dir;
+        struct trace_array              *tr;
+        struct ftrace_subsystem_dir     *system;
+
+        /*
+         * 32 bit flags:
+         *   bit 0:             enabled
+         *   bit 1:             enabled cmd record
+         *   bit 2:             enable/disable with the soft disable bit
+         *   bit 3:             soft disabled
+         *
+         * Note: The bits must be set atomically to prevent races
+         * from other writers. Reads of flags do not need to be in
+         * sync as they occur in critical sections. But the way flags
+         * is currently used, these changes do not affect the code
+         * except that when a change is made, it may have a slight
+         * delay in propagating the changes to other CPUs due to
+         * caching and such. Which is mostly OK ;-)
+         */
+        unsigned long           flags;
+};
+
 #define __TRACE_EVENT_FLAGS(name, value)                                \
         static int __init trace_init_flags_##name(void)                 \
         {                                                               \
@@ -274,7 +333,7 @@ extern int trace_define_field(struct ftrace_event_call *call, const char *type,
 extern int trace_add_event_call(struct ftrace_event_call *call);
 extern void trace_remove_event_call(struct ftrace_event_call *call);
 
-#define is_signed_type(type)    (((type)(-1)) < (type)0)
+#define is_signed_type(type)    (((type)(-1)) < (type)1)
 
 int trace_set_clr_event(const char *system, const char *event, int set);
 
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 79fdd80a42d4..2dac79c39199 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -486,6 +486,8 @@ enum ftrace_dump_mode {
 void tracing_on(void);
 void tracing_off(void);
 int tracing_is_on(void);
+void tracing_snapshot(void);
+void tracing_snapshot_alloc(void);
 
 extern void tracing_start(void);
 extern void tracing_stop(void);
@@ -515,10 +517,32 @@ do {									\
  *
  * This is intended as a debugging tool for the developer only.
  * Please refrain from leaving trace_printks scattered around in
- * your code.
+ * your code. (Extra memory is used for special buffers that are
+ * allocated when trace_printk() is used)
+ *
+ * A little optization trick is done here. If there's only one
+ * argument, there's no need to scan the string for printf formats.
+ * The trace_puts() will suffice. But how can we take advantage of
+ * using trace_puts() when trace_printk() has only one argument?
+ * By stringifying the args and checking the size we can tell
+ * whether or not there are args. __stringify((__VA_ARGS__)) will
+ * turn into "()\0" with a size of 3 when there are no args, anything
+ * else will be bigger. All we need to do is define a string to this,
+ * and then take its size and compare to 3. If it's bigger, use
+ * do_trace_printk() otherwise, optimize it to trace_puts(). Then just
+ * let gcc optimize the rest.
  */
 
-#define trace_printk(fmt, args...)                                      \
+#define trace_printk(fmt, ...)                          \
+do {                                                    \
+        char _______STR[] = __stringify((__VA_ARGS__)); \
+        if (sizeof(_______STR) > 3)                     \
+                do_trace_printk(fmt, ##__VA_ARGS__);    \
+        else                                            \
+                trace_puts(fmt);                        \
+} while (0)
+
+#define do_trace_printk(fmt, args...)                                   \
 do {                                                                    \
         static const char *trace_printk_fmt                             \
                 __attribute__((section("__trace_printk_fmt"))) =        \
@@ -538,7 +562,45 @@ int __trace_bprintk(unsigned long ip, const char *fmt, ...);
 extern __printf(2, 3)
 int __trace_printk(unsigned long ip, const char *fmt, ...);
 
-extern void trace_dump_stack(void);
+/**
+ * trace_puts - write a string into the ftrace buffer
+ * @str: the string to record
+ *
+ * Note: __trace_bputs is an internal function for trace_puts and
+ *       the @ip is passed in via the trace_puts macro.
+ *
+ * This is similar to trace_printk() but is made for those really fast
+ * paths that a developer wants the least amount of "Heisenbug" affects,
+ * where the processing of the print format is still too much.
+ *
+ * This function allows a kernel developer to debug fast path sections
+ * that printk is not appropriate for. By scattering in various
+ * printk like tracing in the code, a developer can quickly see
+ * where problems are occurring.
+ *
+ * This is intended as a debugging tool for the developer only.
+ * Please refrain from leaving trace_puts scattered around in
+ * your code. (Extra memory is used for special buffers that are
+ * allocated when trace_puts() is used)
+ *
+ * Returns: 0 if nothing was written, positive # if string was.
+ *  (1 when __trace_bputs is used, strlen(str) when __trace_puts is used)
+ */
+
+extern int __trace_bputs(unsigned long ip, const char *str);
+extern int __trace_puts(unsigned long ip, const char *str, int size);
+#define trace_puts(str) ({                                              \
+        static const char *trace_printk_fmt                             \
+                __attribute__((section("__trace_printk_fmt"))) =        \
+                __builtin_constant_p(str) ? str : NULL;                 \
+                                                                        \
+        if (__builtin_constant_p(str))                                  \
+                __trace_bputs(_THIS_IP_, trace_printk_fmt);             \
+        else                                                            \
+                __trace_puts(_THIS_IP_, str, strlen(str));              \
+})
+
+extern void trace_dump_stack(int skip);
 
 /*
  * The double __builtin_constant_p is because gcc will give us an error
@@ -573,6 +635,8 @@ static inline void trace_dump_stack(void) { }
 static inline void tracing_on(void) { }
 static inline void tracing_off(void) { }
 static inline int tracing_is_on(void) { return 0; }
+static inline void tracing_snapshot(void) { }
+static inline void tracing_snapshot_alloc(void) { }
 
 static inline __printf(1, 2)
 int trace_printk(const char *fmt, ...)
diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h
index 1342e69542f3..d69cf637a15a 100644
--- a/include/linux/ring_buffer.h
+++ b/include/linux/ring_buffer.h
@@ -4,6 +4,7 @@
 #include <linux/kmemcheck.h>
 #include <linux/mm.h>
 #include <linux/seq_file.h>
+#include <linux/poll.h>
 
 struct ring_buffer;
 struct ring_buffer_iter;
@@ -96,6 +97,11 @@ __ring_buffer_alloc(unsigned long size, unsigned flags, struct lock_class_key *k
         __ring_buffer_alloc((size), (flags), &__key);   \
 })
 
+void ring_buffer_wait(struct ring_buffer *buffer, int cpu);
+int ring_buffer_poll_wait(struct ring_buffer *buffer, int cpu,
+                          struct file *filp, poll_table *poll_table);
+
+
 #define RING_BUFFER_ALL_CPUS -1
 
 void ring_buffer_free(struct ring_buffer *buffer);
diff --git a/include/linux/trace_clock.h b/include/linux/trace_clock.h
index d563f37e1a1d..1d7ca2739272 100644
--- a/include/linux/trace_clock.h
+++ b/include/linux/trace_clock.h
@@ -16,6 +16,7 @@
 
 extern u64 notrace trace_clock_local(void);
 extern u64 notrace trace_clock(void);
+extern u64 notrace trace_clock_jiffies(void);
 extern u64 notrace trace_clock_global(void);
 extern u64 notrace trace_clock_counter(void);