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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0
 
 #ifndef _LINUX_KERNEL_TRACE_H
 #define _LINUX_KERNEL_TRACE_H
 
 #include <linux/fs.h>
 #include <linux/atomic.h>
 #include <linux/sched.h>
 #include <linux/clocksource.h>
 #include <linux/ring_buffer.h>
 #include <linux/mmiotrace.h>
 #include <linux/tracepoint.h>
 #include <linux/ftrace.h>
 #include <linux/trace.h>
 #include <linux/hw_breakpoint.h>
 #include <linux/trace_seq.h>
 #include <linux/trace_events.h>
 #include <linux/compiler.h>
 #include <linux/glob.h>
 #include <linux/irq_work.h>
 #include <linux/workqueue.h>
 #include <linux/ctype.h>
 #include <linux/once_lite.h>
 
 #include "pid_list.h"
 
 #ifdef CONFIG_FTRACE_SYSCALLS
 #include <asm/unistd.h>     /* For NR_SYSCALLS       */
 #include <asm/syscall.h>    /* some archs define it here */
 #endif
 
 #define TRACE_MODE_WRITE    0640
 #define TRACE_MODE_READ     0440
 
 enum trace_type {
     __TRACE_FIRST_TYPE = 0,
 
     TRACE_FN,
     TRACE_CTX,
     TRACE_WAKE,
     TRACE_STACK,
     TRACE_PRINT,
     TRACE_BPRINT,
     TRACE_MMIO_RW,
     TRACE_MMIO_MAP,
     TRACE_BRANCH,
     TRACE_GRAPH_RET,
     TRACE_GRAPH_ENT,
     TRACE_USER_STACK,
     TRACE_BLK,
     TRACE_BPUTS,
     TRACE_HWLAT,
     TRACE_OSNOISE,
     TRACE_TIMERLAT,
     TRACE_RAW_DATA,
     TRACE_FUNC_REPEATS,
 
     __TRACE_LAST_TYPE,
 };
 
 
 #undef __field
 #define __field(type, item)     type    item;
 
 #undef __field_fn
 #define __field_fn(type, item)      type    item;
 
 #undef __field_struct
 #define __field_struct(type, item)  __field(type, item)
 
 #undef __field_desc
 #define __field_desc(type, container, item)
 
 #undef __field_packed
 #define __field_packed(type, container, item)
 
 #undef __array
 #define __array(type, item, size)   type    item[size];
 
 #undef __array_desc
 #define __array_desc(type, container, item, size)
 
 #undef __dynamic_array
 #define __dynamic_array(type, item) type    item[];
 
 #undef __rel_dynamic_array
 #define __rel_dynamic_array(type, item) type    item[];
 
 #undef F_STRUCT
 #define F_STRUCT(args...)       args
 
 #undef FTRACE_ENTRY
 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)     \
     struct struct_name {                        \
         struct trace_entry  ent;                \
         tstruct                         \
     }
 
 #undef FTRACE_ENTRY_DUP
 #define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk)
 
 #undef FTRACE_ENTRY_REG
 #define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print, regfn)  \
     FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print))
 
 #undef FTRACE_ENTRY_PACKED
 #define FTRACE_ENTRY_PACKED(name, struct_name, id, tstruct, print)  \
     FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print)) __packed
 
 #include "trace_entries.h"
 
 /* Use this for memory failure errors */
 #define MEM_FAIL(condition, fmt, ...)                   \
     DO_ONCE_LITE_IF(condition, pr_err, "ERROR: " fmt, ##__VA_ARGS__)
 
 /*
  * syscalls are special, and need special handling, this is why
  * they are not included in trace_entries.h
  */
 struct syscall_trace_enter {
     struct trace_entry  ent;
     int         nr;
     unsigned long       args[];
 };
 
 struct syscall_trace_exit {
     struct trace_entry  ent;
     int         nr;
     long            ret;
 };
 
 struct kprobe_trace_entry_head {
     struct trace_entry  ent;
     unsigned long       ip;
 };
 
 struct eprobe_trace_entry_head {
     struct trace_entry  ent;
 };
 
 struct kretprobe_trace_entry_head {
     struct trace_entry  ent;
     unsigned long       func;
     unsigned long       ret_ip;
 };
 
 #define TRACE_BUF_SIZE      1024
 
 struct trace_array;
 
 /*
  * The CPU trace array - it consists of thousands of trace entries
  * plus some other descriptor data: (for example which task started
  * the trace, etc.)
  */
 struct trace_array_cpu {
     atomic_t        disabled;
     void            *buffer_page;   /* ring buffer spare */
 
     unsigned long       entries;
     unsigned long       saved_latency;
     unsigned long       critical_start;
     unsigned long       critical_end;
     unsigned long       critical_sequence;
     unsigned long       nice;
     unsigned long       policy;
     unsigned long       rt_priority;
     unsigned long       skipped_entries;
     u64         preempt_timestamp;
     pid_t           pid;
     kuid_t          uid;
     char            comm[TASK_COMM_LEN];
 
 #ifdef CONFIG_FUNCTION_TRACER
     int         ftrace_ignore_pid;
 #endif
     bool            ignore_pid;
 };
 
 struct tracer;
 struct trace_option_dentry;
 
 struct array_buffer {
     struct trace_array      *tr;
     struct trace_buffer     *buffer;
     struct trace_array_cpu __percpu *data;
     u64             time_start;
     int             cpu;
 };
 
 #define TRACE_FLAGS_MAX_SIZE        32
 
 struct trace_options {
     struct tracer           *tracer;
     struct trace_option_dentry  *topts;
 };
 
 struct trace_pid_list *trace_pid_list_alloc(void);
 void trace_pid_list_free(struct trace_pid_list *pid_list);
 bool trace_pid_list_is_set(struct trace_pid_list *pid_list, unsigned int pid);
 int trace_pid_list_set(struct trace_pid_list *pid_list, unsigned int pid);
 int trace_pid_list_clear(struct trace_pid_list *pid_list, unsigned int pid);
 int trace_pid_list_first(struct trace_pid_list *pid_list, unsigned int *pid);
 int trace_pid_list_next(struct trace_pid_list *pid_list, unsigned int pid,
             unsigned int *next);
 
 enum {
     TRACE_PIDS      = BIT(0),
     TRACE_NO_PIDS       = BIT(1),
 };
 
 static inline bool pid_type_enabled(int type, struct trace_pid_list *pid_list,
                     struct trace_pid_list *no_pid_list)
 {
     /* Return true if the pid list in type has pids */
     return ((type & TRACE_PIDS) && pid_list) ||
         ((type & TRACE_NO_PIDS) && no_pid_list);
 }
 
 static inline bool still_need_pid_events(int type, struct trace_pid_list *pid_list,
                      struct trace_pid_list *no_pid_list)
 {
     /*
      * Turning off what is in @type, return true if the "other"
      * pid list, still has pids in it.
      */
     return (!(type & TRACE_PIDS) && pid_list) ||
         (!(type & TRACE_NO_PIDS) && no_pid_list);
 }
 
 typedef bool (*cond_update_fn_t)(struct trace_array *tr, void *cond_data);
 
 /**
  * struct cond_snapshot - conditional snapshot data and callback
  *
  * The cond_snapshot structure encapsulates a callback function and
  * data associated with the snapshot for a given tracing instance.
  *
  * When a snapshot is taken conditionally, by invoking
  * tracing_snapshot_cond(tr, cond_data), the cond_data passed in is
  * passed in turn to the cond_snapshot.update() function.  That data
  * can be compared by the update() implementation with the cond_data
  * contained within the struct cond_snapshot instance associated with
  * the trace_array.  Because the tr->max_lock is held throughout the
  * update() call, the update() function can directly retrieve the
  * cond_snapshot and cond_data associated with the per-instance
  * snapshot associated with the trace_array.
  *
  * The cond_snapshot.update() implementation can save data to be
  * associated with the snapshot if it decides to, and returns 'true'
  * in that case, or it returns 'false' if the conditional snapshot
  * shouldn't be taken.
  *
  * The cond_snapshot instance is created and associated with the
  * user-defined cond_data by tracing_cond_snapshot_enable().
  * Likewise, the cond_snapshot instance is destroyed and is no longer
  * associated with the trace instance by
  * tracing_cond_snapshot_disable().
  *
  * The method below is required.
  *
  * @update: When a conditional snapshot is invoked, the update()
  *  callback function is invoked with the tr->max_lock held.  The
  *  update() implementation signals whether or not to actually
  *  take the snapshot, by returning 'true' if so, 'false' if no
  *  snapshot should be taken.  Because the max_lock is held for
  *  the duration of update(), the implementation is safe to
  *  directly retrieved and save any implementation data it needs
  *  to in association with the snapshot.
  */
 struct cond_snapshot {
     void                *cond_data;
     cond_update_fn_t        update;
 };
 
 /*
  * struct trace_func_repeats - used to keep track of the consecutive
  * (on the same CPU) calls of a single function.
  */
 struct trace_func_repeats {
     unsigned long   ip;
     unsigned long   parent_ip;
     unsigned long   count;
     u64     ts_last_call;
 };
 
 /*
  * The trace array - an array of per-CPU trace arrays. This is the
  * highest level data structure that individual tracers deal with.
  * They have on/off state as well:
  */
 struct trace_array {
     struct list_head    list;
     char            *name;
     struct array_buffer array_buffer;
 #ifdef CONFIG_TRACER_MAX_TRACE
     /*
      * The max_buffer is used to snapshot the trace when a maximum
      * latency is reached, or when the user initiates a snapshot.
      * Some tracers will use this to store a maximum trace while
      * it continues examining live traces.
      *
      * The buffers for the max_buffer are set up the same as the array_buffer
      * When a snapshot is taken, the buffer of the max_buffer is swapped
      * with the buffer of the array_buffer and the buffers are reset for
      * the array_buffer so the tracing can continue.
      */
     struct array_buffer max_buffer;
     bool            allocated_snapshot;
 #endif
 #if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER) \
     || defined(CONFIG_OSNOISE_TRACER)
     unsigned long       max_latency;
 #ifdef CONFIG_FSNOTIFY
     struct dentry       *d_max_latency;
     struct work_struct  fsnotify_work;
     struct irq_work     fsnotify_irqwork;
 #endif
 #endif
     struct trace_pid_list   __rcu *filtered_pids;
     struct trace_pid_list   __rcu *filtered_no_pids;
     /*
      * max_lock is used to protect the swapping of buffers
      * when taking a max snapshot. The buffers themselves are
      * protected by per_cpu spinlocks. But the action of the swap
      * needs its own lock.
      *
      * This is defined as a arch_spinlock_t in order to help
      * with performance when lockdep debugging is enabled.
      *
      * It is also used in other places outside the update_max_tr
      * so it needs to be defined outside of the
      * CONFIG_TRACER_MAX_TRACE.
      */
     arch_spinlock_t     max_lock;
     int         buffer_disabled;
 #ifdef CONFIG_FTRACE_SYSCALLS
     int         sys_refcount_enter;
     int         sys_refcount_exit;
     struct trace_event_file __rcu *enter_syscall_files[NR_syscalls];
     struct trace_event_file __rcu *exit_syscall_files[NR_syscalls];
 #endif
     int         stop_count;
     int         clock_id;
     int         nr_topts;
     bool            clear_trace;
     int         buffer_percent;
     unsigned int        n_err_log_entries;
     struct tracer       *current_trace;
     unsigned int        trace_flags;
     unsigned char       trace_flags_index[TRACE_FLAGS_MAX_SIZE];
     unsigned int        flags;
     raw_spinlock_t      start_lock;
     struct list_head    err_log;
     struct dentry       *dir;
     struct dentry       *options;
     struct dentry       *percpu_dir;
     struct dentry       *event_dir;
     struct trace_options    *topts;
     struct list_head    systems;
     struct list_head    events;
     struct trace_event_file *trace_marker_file;
     cpumask_var_t       tracing_cpumask; /* only trace on set CPUs */
     int         ref;
     int         trace_ref;
 #ifdef CONFIG_FUNCTION_TRACER
     struct ftrace_ops   *ops;
     struct trace_pid_list   __rcu *function_pids;
     struct trace_pid_list   __rcu *function_no_pids;
 #ifdef CONFIG_DYNAMIC_FTRACE
     /* All of these are protected by the ftrace_lock */
     struct list_head    func_probes;
     struct list_head    mod_trace;
     struct list_head    mod_notrace;
 #endif
     /* function tracing enabled */
     int         function_enabled;
 #endif
     int         no_filter_buffering_ref;
     struct list_head    hist_vars;
 #ifdef CONFIG_TRACER_SNAPSHOT
     struct cond_snapshot    *cond_snapshot;
 #endif
     struct trace_func_repeats   __percpu *last_func_repeats;
 };
 
 enum {
     TRACE_ARRAY_FL_GLOBAL   = (1 << 0)
 };
 
 extern struct list_head ftrace_trace_arrays;
 
 extern struct mutex trace_types_lock;
 
 extern int trace_array_get(struct trace_array *tr);
 extern int tracing_check_open_get_tr(struct trace_array *tr);
 extern struct trace_array *trace_array_find(const char *instance);
 extern struct trace_array *trace_array_find_get(const char *instance);
 
 extern u64 tracing_event_time_stamp(struct trace_buffer *buffer, struct ring_buffer_event *rbe);
 extern int tracing_set_filter_buffering(struct trace_array *tr, bool set);
 extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);
 
 extern bool trace_clock_in_ns(struct trace_array *tr);
 
 /*
  * The global tracer (top) should be the first trace array added,
  * but we check the flag anyway.
  */
 static inline struct trace_array *top_trace_array(void)
 {
     struct trace_array *tr;
 
     if (list_empty(&ftrace_trace_arrays))
         return NULL;
 
     tr = list_entry(ftrace_trace_arrays.prev,
             typeof(*tr), list);
     WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
     return tr;
 }
 
 #define FTRACE_CMP_TYPE(var, type) \
     __builtin_types_compatible_p(typeof(var), type *)
 
 #undef IF_ASSIGN
 #define IF_ASSIGN(var, entry, etype, id)            \
     if (FTRACE_CMP_TYPE(var, etype)) {          \
         var = (typeof(var))(entry);         \
         WARN_ON(id != 0 && (entry)->type != id);    \
         break;                      \
     }
 
 /* Will cause compile errors if type is not found. */
 extern void __ftrace_bad_type(void);
 
 /*
  * The trace_assign_type is a verifier that the entry type is
  * the same as the type being assigned. To add new types simply
  * add a line with the following format:
  *
  * IF_ASSIGN(var, ent, type, id);
  *
  *  Where "type" is the trace type that includes the trace_entry
  *  as the "ent" item. And "id" is the trace identifier that is
  *  used in the trace_type enum.
  *
  *  If the type can have more than one id, then use zero.
  */
 #define trace_assign_type(var, ent)                 \
     do {                                \
         IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN); \
         IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);    \
         IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);   \
         IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
         IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);   \
         IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \
         IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS);   \
         IF_ASSIGN(var, ent, struct hwlat_entry, TRACE_HWLAT);   \
         IF_ASSIGN(var, ent, struct osnoise_entry, TRACE_OSNOISE);\
         IF_ASSIGN(var, ent, struct timerlat_entry, TRACE_TIMERLAT);\
         IF_ASSIGN(var, ent, struct raw_data_entry, TRACE_RAW_DATA);\
         IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,      \
               TRACE_MMIO_RW);               \
         IF_ASSIGN(var, ent, struct trace_mmiotrace_map,     \
               TRACE_MMIO_MAP);              \
         IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
         IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,  \
               TRACE_GRAPH_ENT);     \
         IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,  \
               TRACE_GRAPH_RET);     \
         IF_ASSIGN(var, ent, struct func_repeats_entry,      \
               TRACE_FUNC_REPEATS);              \
         __ftrace_bad_type();                    \
     } while (0)
 
 /*
  * An option specific to a tracer. This is a boolean value.
  * The bit is the bit index that sets its value on the
  * flags value in struct tracer_flags.
  */
 struct tracer_opt {
     const char  *name; /* Will appear on the trace_options file */
     u32     bit; /* Mask assigned in val field in tracer_flags */
 };
 
 /*
  * The set of specific options for a tracer. Your tracer
  * have to set the initial value of the flags val.
  */
 struct tracer_flags {
     u32         val;
     struct tracer_opt   *opts;
     struct tracer       *trace;
 };
 
 /* Makes more easy to define a tracer opt */
 #define TRACER_OPT(s, b)    .name = #s, .bit = b
 
 
 struct trace_option_dentry {
     struct tracer_opt       *opt;
     struct tracer_flags     *flags;
     struct trace_array      *tr;
     struct dentry           *entry;
 };
 
 /**
  * struct tracer - a specific tracer and its callbacks to interact with tracefs
  * @name: the name chosen to select it on the available_tracers file
  * @init: called when one switches to this tracer (echo name > current_tracer)
  * @reset: called when one switches to another tracer
  * @start: called when tracing is unpaused (echo 1 > tracing_on)
  * @stop: called when tracing is paused (echo 0 > tracing_on)
  * @update_thresh: called when tracing_thresh is updated
  * @open: called when the trace file is opened
  * @pipe_open: called when the trace_pipe file is opened
  * @close: called when the trace file is released
  * @pipe_close: called when the trace_pipe file is released
  * @read: override the default read callback on trace_pipe
  * @splice_read: override the default splice_read callback on trace_pipe
  * @selftest: selftest to run on boot (see trace_selftest.c)
  * @print_headers: override the first lines that describe your columns
  * @print_line: callback that prints a trace
  * @set_flag: signals one of your private flags changed (trace_options file)
  * @flags: your private flags
  */
 struct tracer {
     const char      *name;
     int         (*init)(struct trace_array *tr);
     void            (*reset)(struct trace_array *tr);
     void            (*start)(struct trace_array *tr);
     void            (*stop)(struct trace_array *tr);
     int         (*update_thresh)(struct trace_array *tr);
     void            (*open)(struct trace_iterator *iter);
     void            (*pipe_open)(struct trace_iterator *iter);
     void            (*close)(struct trace_iterator *iter);
     void            (*pipe_close)(struct trace_iterator *iter);
     ssize_t         (*read)(struct trace_iterator *iter,
                     struct file *filp, char __user *ubuf,
                     size_t cnt, loff_t *ppos);
     ssize_t         (*splice_read)(struct trace_iterator *iter,
                            struct file *filp,
                            loff_t *ppos,
                            struct pipe_inode_info *pipe,
                            size_t len,
                            unsigned int flags);
 #ifdef CONFIG_FTRACE_STARTUP_TEST
     int         (*selftest)(struct tracer *trace,
                         struct trace_array *tr);
 #endif
     void            (*print_header)(struct seq_file *m);
     enum print_line_t   (*print_line)(struct trace_iterator *iter);
     /* If you handled the flag setting, return 0 */
     int         (*set_flag)(struct trace_array *tr,
                         u32 old_flags, u32 bit, int set);
     /* Return 0 if OK with change, else return non-zero */
     int         (*flag_changed)(struct trace_array *tr,
                         u32 mask, int set);
     struct tracer       *next;
     struct tracer_flags *flags;
     int         enabled;
     bool            print_max;
     bool            allow_instances;
 #ifdef CONFIG_TRACER_MAX_TRACE
     bool            use_max_tr;
 #endif
     /* True if tracer cannot be enabled in kernel param */
     bool            noboot;
 };
 
 static inline struct ring_buffer_iter *
 trace_buffer_iter(struct trace_iterator *iter, int cpu)
 {
     return iter->buffer_iter ? iter->buffer_iter[cpu] : NULL;
 }
 
 int tracer_init(struct tracer *t, struct trace_array *tr);
 int tracing_is_enabled(void);
 void tracing_reset_online_cpus(struct array_buffer *buf);
 void tracing_reset_current(int cpu);
 void tracing_reset_all_online_cpus(void);
 int tracing_open_generic(struct inode *inode, struct file *filp);
 int tracing_open_generic_tr(struct inode *inode, struct file *filp);
 bool tracing_is_disabled(void);
 bool tracer_tracing_is_on(struct trace_array *tr);
 void tracer_tracing_on(struct trace_array *tr);
 void tracer_tracing_off(struct trace_array *tr);
 struct dentry *trace_create_file(const char *name,
                  umode_t mode,
                  struct dentry *parent,
                  void *data,
                  const struct file_operations *fops);
 
 int tracing_init_dentry(void);
 
 struct ring_buffer_event;
 
 struct ring_buffer_event *
 trace_buffer_lock_reserve(struct trace_buffer *buffer,
               int type,
               unsigned long len,
               unsigned int trace_ctx);
 
 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
                         struct trace_array_cpu *data);
 
 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
                       int *ent_cpu, u64 *ent_ts);
 
 void trace_buffer_unlock_commit_nostack(struct trace_buffer *buffer,
                     struct ring_buffer_event *event);
 
 bool trace_is_tracepoint_string(const char *str);
 const char *trace_event_format(struct trace_iterator *iter, const char *fmt);
 void trace_check_vprintf(struct trace_iterator *iter, const char *fmt,
              va_list ap);
 
 int trace_empty(struct trace_iterator *iter);
 
 void *trace_find_next_entry_inc(struct trace_iterator *iter);
 
 void trace_init_global_iter(struct trace_iterator *iter);
 
 void tracing_iter_reset(struct trace_iterator *iter, int cpu);
 
 unsigned long trace_total_entries_cpu(struct trace_array *tr, int cpu);
 unsigned long trace_total_entries(struct trace_array *tr);
 
 void trace_function(struct trace_array *tr,
             unsigned long ip,
             unsigned long parent_ip,
             unsigned int trace_ctx);
 void trace_graph_function(struct trace_array *tr,
             unsigned long ip,
             unsigned long parent_ip,
             unsigned int trace_ctx);
 void trace_latency_header(struct seq_file *m);
 void trace_default_header(struct seq_file *m);
 void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
 
 void trace_graph_return(struct ftrace_graph_ret *trace);
 int trace_graph_entry(struct ftrace_graph_ent *trace);
 void set_graph_array(struct trace_array *tr);
 
 void tracing_start_cmdline_record(void);
 void tracing_stop_cmdline_record(void);
 void tracing_start_tgid_record(void);
 void tracing_stop_tgid_record(void);
 
 int register_tracer(struct tracer *type);
 int is_tracing_stopped(void);
 
 loff_t tracing_lseek(struct file *file, loff_t offset, int whence);
 
 extern cpumask_var_t __read_mostly tracing_buffer_mask;
 
 #define for_each_tracing_cpu(cpu)   \
     for_each_cpu(cpu, tracing_buffer_mask)
 
 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
 
 extern unsigned long tracing_thresh;
 
 /* PID filtering */
 
 extern int pid_max;
 
 bool trace_find_filtered_pid(struct trace_pid_list *filtered_pids,
                  pid_t search_pid);
 bool trace_ignore_this_task(struct trace_pid_list *filtered_pids,
                 struct trace_pid_list *filtered_no_pids,
                 struct task_struct *task);
 void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
                   struct task_struct *self,
                   struct task_struct *task);
 void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
 void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
 int trace_pid_show(struct seq_file *m, void *v);
 void trace_free_pid_list(struct trace_pid_list *pid_list);
 int trace_pid_write(struct trace_pid_list *filtered_pids,
             struct trace_pid_list **new_pid_list,
             const char __user *ubuf, size_t cnt);
 
 #ifdef CONFIG_TRACER_MAX_TRACE
 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu,
            void *cond_data);
 void update_max_tr_single(struct trace_array *tr,
               struct task_struct *tsk, int cpu);
 #endif /* CONFIG_TRACER_MAX_TRACE */
 
 #if (defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER) \
     || defined(CONFIG_OSNOISE_TRACER)) && defined(CONFIG_FSNOTIFY)
 #define LATENCY_FS_NOTIFY
 #endif
 
 #ifdef LATENCY_FS_NOTIFY
 void latency_fsnotify(struct trace_array *tr);
 #else
 static inline void latency_fsnotify(struct trace_array *tr) { }
 #endif
 
 #ifdef CONFIG_STACKTRACE
 void __trace_stack(struct trace_array *tr, unsigned int trace_ctx, int skip);
 #else
 static inline void __trace_stack(struct trace_array *tr, unsigned int trace_ctx,
                  int skip)
 {
 }
 #endif /* CONFIG_STACKTRACE */
 
 void trace_last_func_repeats(struct trace_array *tr,
                  struct trace_func_repeats *last_info,
                  unsigned int trace_ctx);
 
 extern u64 ftrace_now(int cpu);
 
 extern void trace_find_cmdline(int pid, char comm[]);
 extern int trace_find_tgid(int pid);
 extern void trace_event_follow_fork(struct trace_array *tr, bool enable);
 
 #ifdef CONFIG_DYNAMIC_FTRACE
 extern unsigned long ftrace_update_tot_cnt;
 extern unsigned long ftrace_number_of_pages;
 extern unsigned long ftrace_number_of_groups;
 void ftrace_init_trace_array(struct trace_array *tr);
 #else
 static inline void ftrace_init_trace_array(struct trace_array *tr) { }
 #endif
 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
 extern int DYN_FTRACE_TEST_NAME(void);
 #define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
 extern int DYN_FTRACE_TEST_NAME2(void);
 
 extern bool ring_buffer_expanded;
 extern bool tracing_selftest_disabled;
 
 #ifdef CONFIG_FTRACE_STARTUP_TEST
 extern void __init disable_tracing_selftest(const char *reason);
 
 extern int trace_selftest_startup_function(struct tracer *trace,
                        struct trace_array *tr);
 extern int trace_selftest_startup_function_graph(struct tracer *trace,
                          struct trace_array *tr);
 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
                       struct trace_array *tr);
 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
                          struct trace_array *tr);
 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
                          struct trace_array *tr);
 extern int trace_selftest_startup_wakeup(struct tracer *trace,
                      struct trace_array *tr);
 extern int trace_selftest_startup_nop(struct tracer *trace,
                      struct trace_array *tr);
 extern int trace_selftest_startup_branch(struct tracer *trace,
                      struct trace_array *tr);
 /*
  * Tracer data references selftest functions that only occur
  * on boot up. These can be __init functions. Thus, when selftests
  * are enabled, then the tracers need to reference __init functions.
  */
 #define __tracer_data       __refdata
 #else
 static inline void __init disable_tracing_selftest(const char *reason)
 {
 }
 /* Tracers are seldom changed. Optimize when selftests are disabled. */
 #define __tracer_data       __read_mostly
 #endif /* CONFIG_FTRACE_STARTUP_TEST */
 
 extern void *head_page(struct trace_array_cpu *data);
 extern unsigned long long ns2usecs(u64 nsec);
 extern int
 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
 extern int
 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
 extern int
 trace_array_vprintk(struct trace_array *tr,
             unsigned long ip, const char *fmt, va_list args);
 int trace_array_printk_buf(struct trace_buffer *buffer,
                unsigned long ip, const char *fmt, ...);
 void trace_printk_seq(struct trace_seq *s);
 enum print_line_t print_trace_line(struct trace_iterator *iter);
 
 extern char trace_find_mark(unsigned long long duration);
 
 struct ftrace_hash;
 
 struct ftrace_mod_load {
     struct list_head    list;
     char            *func;
     char            *module;
     int          enable;
 };
 
 enum {
     FTRACE_HASH_FL_MOD  = (1 << 0),
 };
 
 struct ftrace_hash {
     unsigned long       size_bits;
     struct hlist_head   *buckets;
     unsigned long       count;
     unsigned long       flags;
     struct rcu_head     rcu;
 };
 
 struct ftrace_func_entry *
 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
 
 static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
 {
     return !hash || !(hash->count || (hash->flags & FTRACE_HASH_FL_MOD));
 }
 
 /* Standard output formatting function used for function return traces */
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 
 /* Flag options */
 #define TRACE_GRAPH_PRINT_OVERRUN       0x1
 #define TRACE_GRAPH_PRINT_CPU           0x2
 #define TRACE_GRAPH_PRINT_OVERHEAD      0x4
 #define TRACE_GRAPH_PRINT_PROC          0x8
 #define TRACE_GRAPH_PRINT_DURATION      0x10
 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
 #define TRACE_GRAPH_PRINT_REL_TIME      0x40
 #define TRACE_GRAPH_PRINT_IRQS          0x80
 #define TRACE_GRAPH_PRINT_TAIL          0x100
 #define TRACE_GRAPH_SLEEP_TIME          0x200
 #define TRACE_GRAPH_GRAPH_TIME          0x400
 #define TRACE_GRAPH_PRINT_FILL_SHIFT    28
 #define TRACE_GRAPH_PRINT_FILL_MASK (0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
 
 extern void ftrace_graph_sleep_time_control(bool enable);
 
 #ifdef CONFIG_FUNCTION_PROFILER
 extern void ftrace_graph_graph_time_control(bool enable);
 #else
 static inline void ftrace_graph_graph_time_control(bool enable) { }
 #endif
 
 extern enum print_line_t
 print_graph_function_flags(struct trace_iterator *iter, u32 flags);
 extern void print_graph_headers_flags(struct seq_file *s, u32 flags);
 extern void
 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
 extern void graph_trace_open(struct trace_iterator *iter);
 extern void graph_trace_close(struct trace_iterator *iter);
 extern int __trace_graph_entry(struct trace_array *tr,
                    struct ftrace_graph_ent *trace,
                    unsigned int trace_ctx);
 extern void __trace_graph_return(struct trace_array *tr,
                  struct ftrace_graph_ret *trace,
                  unsigned int trace_ctx);
 
 #ifdef CONFIG_DYNAMIC_FTRACE
 extern struct ftrace_hash __rcu *ftrace_graph_hash;
 extern struct ftrace_hash __rcu *ftrace_graph_notrace_hash;
 
 static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
 {
     unsigned long addr = trace->func;
     int ret = 0;
     struct ftrace_hash *hash;
 
     preempt_disable_notrace();
 
     /*
      * Have to open code "rcu_dereference_sched()" because the
      * function graph tracer can be called when RCU is not
      * "watching".
      * Protected with schedule_on_each_cpu(ftrace_sync)
      */
     hash = rcu_dereference_protected(ftrace_graph_hash, !preemptible());
 
     if (ftrace_hash_empty(hash)) {
         ret = 1;
         goto out;
     }
 
     if (ftrace_lookup_ip(hash, addr)) {
 
         /*
          * This needs to be cleared on the return functions
          * when the depth is zero.
          */
         trace_recursion_set(TRACE_GRAPH_BIT);
         trace_recursion_set_depth(trace->depth);
 
         /*
          * If no irqs are to be traced, but a set_graph_function
          * is set, and called by an interrupt handler, we still
          * want to trace it.
          */
         if (in_hardirq())
             trace_recursion_set(TRACE_IRQ_BIT);
         else
             trace_recursion_clear(TRACE_IRQ_BIT);
         ret = 1;
     }
 
 out:
     preempt_enable_notrace();
     return ret;
 }
 
 static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
 {
     if (trace_recursion_test(TRACE_GRAPH_BIT) &&
         trace->depth == trace_recursion_depth())
         trace_recursion_clear(TRACE_GRAPH_BIT);
 }
 
 static inline int ftrace_graph_notrace_addr(unsigned long addr)
 {
     int ret = 0;
     struct ftrace_hash *notrace_hash;
 
     preempt_disable_notrace();
 
     /*
      * Have to open code "rcu_dereference_sched()" because the
      * function graph tracer can be called when RCU is not
      * "watching".
      * Protected with schedule_on_each_cpu(ftrace_sync)
      */
     notrace_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
                          !preemptible());
 
     if (ftrace_lookup_ip(notrace_hash, addr))
         ret = 1;
 
     preempt_enable_notrace();
     return ret;
 }
 #else
 static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
 {
     return 1;
 }
 
 static inline int ftrace_graph_notrace_addr(unsigned long addr)
 {
     return 0;
 }
 static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
 { }
 #endif /* CONFIG_DYNAMIC_FTRACE */
 
 extern unsigned int fgraph_max_depth;
 
 static inline bool ftrace_graph_ignore_func(struct ftrace_graph_ent *trace)
 {
     /* trace it when it is-nested-in or is a function enabled. */
     return !(trace_recursion_test(TRACE_GRAPH_BIT) ||
          ftrace_graph_addr(trace)) ||
         (trace->depth < 0) ||
         (fgraph_max_depth && trace->depth >= fgraph_max_depth);
 }
 
 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
 static inline enum print_line_t
 print_graph_function_flags(struct trace_iterator *iter, u32 flags)
 {
     return TRACE_TYPE_UNHANDLED;
 }
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 
 extern struct list_head ftrace_pids;
 
 #ifdef CONFIG_FUNCTION_TRACER
 
 #define FTRACE_PID_IGNORE   -1
 #define FTRACE_PID_TRACE    -2
 
 struct ftrace_func_command {
     struct list_head    list;
     char            *name;
     int         (*func)(struct trace_array *tr,
                     struct ftrace_hash *hash,
                     char *func, char *cmd,
                     char *params, int enable);
 };
 extern bool ftrace_filter_param __initdata;
 static inline int ftrace_trace_task(struct trace_array *tr)
 {
     return this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid) !=
         FTRACE_PID_IGNORE;
 }
 extern int ftrace_is_dead(void);
 int ftrace_create_function_files(struct trace_array *tr,
                  struct dentry *parent);
 void ftrace_destroy_function_files(struct trace_array *tr);
 int ftrace_allocate_ftrace_ops(struct trace_array *tr);
 void ftrace_free_ftrace_ops(struct trace_array *tr);
 void ftrace_init_global_array_ops(struct trace_array *tr);
 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
 void ftrace_reset_array_ops(struct trace_array *tr);
 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);
 void ftrace_init_tracefs_toplevel(struct trace_array *tr,
                   struct dentry *d_tracer);
 void ftrace_clear_pids(struct trace_array *tr);
 int init_function_trace(void);
 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable);
 #else
 static inline int ftrace_trace_task(struct trace_array *tr)
 {
     return 1;
 }
 static inline int ftrace_is_dead(void) { return 0; }
 static inline int
 ftrace_create_function_files(struct trace_array *tr,
                  struct dentry *parent)
 {
     return 0;
 }
 static inline int ftrace_allocate_ftrace_ops(struct trace_array *tr)
 {
     return 0;
 }
 static inline void ftrace_free_ftrace_ops(struct trace_array *tr) { }
 static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
 static inline __init void
 ftrace_init_global_array_ops(struct trace_array *tr) { }
 static inline void ftrace_reset_array_ops(struct trace_array *tr) { }
 static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }
 static inline void ftrace_init_tracefs_toplevel(struct trace_array *tr, struct dentry *d) { }
 static inline void ftrace_clear_pids(struct trace_array *tr) { }
 static inline int init_function_trace(void) { return 0; }
 static inline void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) { }
 /* ftace_func_t type is not defined, use macro instead of static inline */
 #define ftrace_init_array_ops(tr, func) do { } while (0)
 #endif /* CONFIG_FUNCTION_TRACER */
 
 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
 
 struct ftrace_probe_ops {
     void            (*func)(unsigned long ip,
                     unsigned long parent_ip,
                     struct trace_array *tr,
                     struct ftrace_probe_ops *ops,
                     void *data);
     int         (*init)(struct ftrace_probe_ops *ops,
                     struct trace_array *tr,
                     unsigned long ip, void *init_data,
                     void **data);
     void            (*free)(struct ftrace_probe_ops *ops,
                     struct trace_array *tr,
                     unsigned long ip, void *data);
     int         (*print)(struct seq_file *m,
                      unsigned long ip,
                      struct ftrace_probe_ops *ops,
                      void *data);
 };
 
 struct ftrace_func_mapper;
 typedef int (*ftrace_mapper_func)(void *data);
 
 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void);
 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
                        unsigned long ip);
 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
                    unsigned long ip, void *data);
 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
                    unsigned long ip);
 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
                  ftrace_mapper_func free_func);
 
 extern int
 register_ftrace_function_probe(char *glob, struct trace_array *tr,
                    struct ftrace_probe_ops *ops, void *data);
 extern int
 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
                       struct ftrace_probe_ops *ops);
 extern void clear_ftrace_function_probes(struct trace_array *tr);
 
 int register_ftrace_command(struct ftrace_func_command *cmd);
 int unregister_ftrace_command(struct ftrace_func_command *cmd);
 
 void ftrace_create_filter_files(struct ftrace_ops *ops,
                 struct dentry *parent);
 void ftrace_destroy_filter_files(struct ftrace_ops *ops);
 
 extern int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
                  int len, int reset);
 extern int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
                   int len, int reset);
 #else
 struct ftrace_func_command;
 
 static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
 {
     return -EINVAL;
 }
 static inline __init int unregister_ftrace_command(char *cmd_name)
 {
     return -EINVAL;
 }
 static inline void clear_ftrace_function_probes(struct trace_array *tr)
 {
 }
 
 /*
  * The ops parameter passed in is usually undefined.
  * This must be a macro.
  */
 #define ftrace_create_filter_files(ops, parent) do { } while (0)
 #define ftrace_destroy_filter_files(ops) do { } while (0)
 #endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */
 
 bool ftrace_event_is_function(struct trace_event_call *call);
 
 /*
  * struct trace_parser - servers for reading the user input separated by spaces
  * @cont: set if the input is not complete - no final space char was found
  * @buffer: holds the parsed user input
  * @idx: user input length
  * @size: buffer size
  */
 struct trace_parser {
     bool        cont;
     char        *buffer;
     unsigned    idx;
     unsigned    size;
 };
 
 static inline bool trace_parser_loaded(struct trace_parser *parser)
 {
     return (parser->idx != 0);
 }
 
 static inline bool trace_parser_cont(struct trace_parser *parser)
 {
     return parser->cont;
 }
 
 static inline void trace_parser_clear(struct trace_parser *parser)
 {
     parser->cont = false;
     parser->idx = 0;
 }
 
 extern int trace_parser_get_init(struct trace_parser *parser, int size);
 extern void trace_parser_put(struct trace_parser *parser);
 extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
     size_t cnt, loff_t *ppos);
 
 /*
  * Only create function graph options if function graph is configured.
  */
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 # define FGRAPH_FLAGS                       \
         C(DISPLAY_GRAPH,    "display-graph"),
 #else
 # define FGRAPH_FLAGS
 #endif
 
 #ifdef CONFIG_BRANCH_TRACER
 # define BRANCH_FLAGS                   \
         C(BRANCH,       "branch"),
 #else
 # define BRANCH_FLAGS
 #endif
 
 #ifdef CONFIG_FUNCTION_TRACER
 # define FUNCTION_FLAGS                     \
         C(FUNCTION,     "function-trace"),  \
         C(FUNC_FORK,        "function-fork"),
 # define FUNCTION_DEFAULT_FLAGS     TRACE_ITER_FUNCTION
 #else
 # define FUNCTION_FLAGS
 # define FUNCTION_DEFAULT_FLAGS     0UL
 # define TRACE_ITER_FUNC_FORK       0UL
 #endif
 
 #ifdef CONFIG_STACKTRACE
 # define STACK_FLAGS                \
         C(STACKTRACE,       "stacktrace"),
 #else
 # define STACK_FLAGS
 #endif
 
 /*
  * trace_iterator_flags is an enumeration that defines bit
  * positions into trace_flags that controls the output.
  *
  * NOTE: These bits must match the trace_options array in
  *       trace.c (this macro guarantees it).
  */
 #define TRACE_FLAGS                     \
         C(PRINT_PARENT,     "print-parent"),    \
         C(SYM_OFFSET,       "sym-offset"),      \
         C(SYM_ADDR,     "sym-addr"),        \
         C(VERBOSE,      "verbose"),     \
         C(RAW,          "raw"),         \
         C(HEX,          "hex"),         \
         C(BIN,          "bin"),         \
         C(BLOCK,        "block"),       \
         C(PRINTK,       "trace_printk"),    \
         C(ANNOTATE,     "annotate"),        \
         C(USERSTACKTRACE,   "userstacktrace"),  \
         C(SYM_USEROBJ,      "sym-userobj"),     \
         C(PRINTK_MSGONLY,   "printk-msg-only"), \
         C(CONTEXT_INFO,     "context-info"),   /* Print pid/cpu/time */ \
         C(LATENCY_FMT,      "latency-format"),  \
         C(RECORD_CMD,       "record-cmd"),      \
         C(RECORD_TGID,      "record-tgid"),     \
         C(OVERWRITE,        "overwrite"),       \
         C(STOP_ON_FREE,     "disable_on_free"), \
         C(IRQ_INFO,     "irq-info"),        \
         C(MARKERS,      "markers"),     \
         C(EVENT_FORK,       "event-fork"),      \
         C(PAUSE_ON_TRACE,   "pause-on-trace"),  \
         C(HASH_PTR,     "hash-ptr"),    /* Print hashed pointer */ \
         FUNCTION_FLAGS                  \
         FGRAPH_FLAGS                    \
         STACK_FLAGS                 \
         BRANCH_FLAGS
 
 /*
  * By defining C, we can make TRACE_FLAGS a list of bit names
  * that will define the bits for the flag masks.
  */
 #undef C
 #define C(a, b) TRACE_ITER_##a##_BIT
 
 enum trace_iterator_bits {
     TRACE_FLAGS
     /* Make sure we don't go more than we have bits for */
     TRACE_ITER_LAST_BIT
 };
 
 /*
  * By redefining C, we can make TRACE_FLAGS a list of masks that
  * use the bits as defined above.
  */
 #undef C
 #define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT)
 
 enum trace_iterator_flags { TRACE_FLAGS };
 
 /*
  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
  * control the output of kernel symbols.
  */
 #define TRACE_ITER_SYM_MASK \
     (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
 
 extern struct tracer nop_trace;
 
 #ifdef CONFIG_BRANCH_TRACER
 extern int enable_branch_tracing(struct trace_array *tr);
 extern void disable_branch_tracing(void);
 static inline int trace_branch_enable(struct trace_array *tr)
 {
     if (tr->trace_flags & TRACE_ITER_BRANCH)
         return enable_branch_tracing(tr);
     return 0;
 }
 static inline void trace_branch_disable(void)
 {
     /* due to races, always disable */
     disable_branch_tracing();
 }
 #else
 static inline int trace_branch_enable(struct trace_array *tr)
 {
     return 0;
 }
 static inline void trace_branch_disable(void)
 {
 }
 #endif /* CONFIG_BRANCH_TRACER */
 
 /* set ring buffers to default size if not already done so */
 int tracing_update_buffers(void);
 
 struct ftrace_event_field {
     struct list_head    link;
     const char      *name;
     const char      *type;
     int         filter_type;
     int         offset;
     int         size;
     int         is_signed;
 };
 
 struct prog_entry;
 
 struct event_filter {
     struct prog_entry __rcu *prog;
     char            *filter_string;
 };
 
 struct event_subsystem {
     struct list_head    list;
     const char      *name;
     struct event_filter *filter;
     int         ref_count;
 };
 
 struct trace_subsystem_dir {
     struct list_head        list;
     struct event_subsystem      *subsystem;
     struct trace_array      *tr;
     struct dentry           *entry;
     int             ref_count;
     int             nr_events;
 };
 
 extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
                      struct trace_buffer *buffer,
                      struct ring_buffer_event *event);
 
 void trace_buffer_unlock_commit_regs(struct trace_array *tr,
                      struct trace_buffer *buffer,
                      struct ring_buffer_event *event,
                      unsigned int trcace_ctx,
                      struct pt_regs *regs);
 
 static inline void trace_buffer_unlock_commit(struct trace_array *tr,
                           struct trace_buffer *buffer,
                           struct ring_buffer_event *event,
                           unsigned int trace_ctx)
 {
     trace_buffer_unlock_commit_regs(tr, buffer, event, trace_ctx, NULL);
 }
 
 DECLARE_PER_CPU(struct ring_buffer_event *, trace_buffered_event);
 DECLARE_PER_CPU(int, trace_buffered_event_cnt);
 void trace_buffered_event_disable(void);
 void trace_buffered_event_enable(void);
 
 static inline void
 __trace_event_discard_commit(struct trace_buffer *buffer,
                  struct ring_buffer_event *event)
 {
     if (this_cpu_read(trace_buffered_event) == event) {
         /* Simply release the temp buffer and enable preemption */
         this_cpu_dec(trace_buffered_event_cnt);
         preempt_enable_notrace();
         return;
     }
     /* ring_buffer_discard_commit() enables preemption */
     ring_buffer_discard_commit(buffer, event);
 }
 
 /*
  * Helper function for event_trigger_unlock_commit{_regs}().
  * If there are event triggers attached to this event that requires
  * filtering against its fields, then they will be called as the
  * entry already holds the field information of the current event.
  *
  * It also checks if the event should be discarded or not.
  * It is to be discarded if the event is soft disabled and the
  * event was only recorded to process triggers, or if the event
  * filter is active and this event did not match the filters.
  *
  * Returns true if the event is discarded, false otherwise.
  */
 static inline bool
 __event_trigger_test_discard(struct trace_event_file *file,
                  struct trace_buffer *buffer,
                  struct ring_buffer_event *event,
                  void *entry,
                  enum event_trigger_type *tt)
 {
     unsigned long eflags = file->flags;
 
     if (eflags & EVENT_FILE_FL_TRIGGER_COND)
         *tt = event_triggers_call(file, buffer, entry, event);
 
     if (likely(!(file->flags & (EVENT_FILE_FL_SOFT_DISABLED |
                     EVENT_FILE_FL_FILTERED |
                     EVENT_FILE_FL_PID_FILTER))))
         return false;
 
     if (file->flags & EVENT_FILE_FL_SOFT_DISABLED)
         goto discard;
 
     if (file->flags & EVENT_FILE_FL_FILTERED &&
         !filter_match_preds(file->filter, entry))
         goto discard;
 
     if ((file->flags & EVENT_FILE_FL_PID_FILTER) &&
         trace_event_ignore_this_pid(file))
         goto discard;
 
     return false;
  discard:
     __trace_event_discard_commit(buffer, event);
     return true;
 }
 
 /**
  * event_trigger_unlock_commit - handle triggers and finish event commit
  * @file: The file pointer associated with the event
  * @buffer: The ring buffer that the event is being written to
  * @event: The event meta data in the ring buffer
  * @entry: The event itself
  * @trace_ctx: The tracing context flags.
  *
  * This is a helper function to handle triggers that require data
  * from the event itself. It also tests the event against filters and
  * if the event is soft disabled and should be discarded.
  */
 static inline void
 event_trigger_unlock_commit(struct trace_event_file *file,
                 struct trace_buffer *buffer,
                 struct ring_buffer_event *event,
                 void *entry, unsigned int trace_ctx)
 {
     enum event_trigger_type tt = ETT_NONE;
 
     if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
         trace_buffer_unlock_commit(file->tr, buffer, event, trace_ctx);
 
     if (tt)
         event_triggers_post_call(file, tt);
 }
 
 #define FILTER_PRED_INVALID ((unsigned short)-1)
 #define FILTER_PRED_IS_RIGHT    (1 << 15)
 #define FILTER_PRED_FOLD    (1 << 15)
 
 /*
  * The max preds is the size of unsigned short with
  * two flags at the MSBs. One bit is used for both the IS_RIGHT
  * and FOLD flags. The other is reserved.
  *
  * 2^14 preds is way more than enough.
  */
 #define MAX_FILTER_PRED     16384
 
 struct filter_pred;
 struct regex;
 
 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event);
 
 typedef int (*regex_match_func)(char *str, struct regex *r, int len);
 
 enum regex_type {
     MATCH_FULL = 0,
     MATCH_FRONT_ONLY,
     MATCH_MIDDLE_ONLY,
     MATCH_END_ONLY,
     MATCH_GLOB,
     MATCH_INDEX,
 };
 
 struct regex {
     char            pattern[MAX_FILTER_STR_VAL];
     int         len;
     int         field_len;
     regex_match_func    match;
 };
 
 struct filter_pred {
     filter_pred_fn_t    fn;
     u64             val;
     struct regex        regex;
     unsigned short      *ops;
     struct ftrace_event_field *field;
     int             offset;
     int         not;
     int             op;
 };
 
 static inline bool is_string_field(struct ftrace_event_field *field)
 {
     return field->filter_type == FILTER_DYN_STRING ||
            field->filter_type == FILTER_RDYN_STRING ||
            field->filter_type == FILTER_STATIC_STRING ||
            field->filter_type == FILTER_PTR_STRING ||
            field->filter_type == FILTER_COMM;
 }
 
 static inline bool is_function_field(struct ftrace_event_field *field)
 {
     return field->filter_type == FILTER_TRACE_FN;
 }
 
 extern enum regex_type
 filter_parse_regex(char *buff, int len, char **search, int *not);
 extern void print_event_filter(struct trace_event_file *file,
                    struct trace_seq *s);
 extern int apply_event_filter(struct trace_event_file *file,
                   char *filter_string);
 extern int apply_subsystem_event_filter(struct trace_subsystem_dir *dir,
                     char *filter_string);
 extern void print_subsystem_event_filter(struct event_subsystem *system,
                      struct trace_seq *s);
 extern int filter_assign_type(const char *type);
 extern int create_event_filter(struct trace_array *tr,
                    struct trace_event_call *call,
                    char *filter_str, bool set_str,
                    struct event_filter **filterp);
 extern void free_event_filter(struct event_filter *filter);
 
 struct ftrace_event_field *
 trace_find_event_field(struct trace_event_call *call, char *name);
 
 extern void trace_event_enable_cmd_record(bool enable);
 extern void trace_event_enable_tgid_record(bool enable);
 
 extern int event_trace_init(void);
 extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
 extern int event_trace_del_tracer(struct trace_array *tr);
 extern void __trace_early_add_events(struct trace_array *tr);
 
 extern struct trace_event_file *__find_event_file(struct trace_array *tr,
                           const char *system,
                           const char *event);
 extern struct trace_event_file *find_event_file(struct trace_array *tr,
                         const char *system,
                         const char *event);
 
 static inline void *event_file_data(struct file *filp)
 {
     return READ_ONCE(file_inode(filp)->i_private);
 }
 
 extern struct mutex event_mutex;
 extern struct list_head ftrace_events;
 
 extern const struct file_operations event_trigger_fops;
 extern const struct file_operations event_hist_fops;
 extern const struct file_operations event_hist_debug_fops;
 extern const struct file_operations event_inject_fops;
 
 #ifdef CONFIG_HIST_TRIGGERS
 extern int register_trigger_hist_cmd(void);
 extern int register_trigger_hist_enable_disable_cmds(void);
 #else
 static inline int register_trigger_hist_cmd(void) { return 0; }
 static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; }
 #endif
 
 extern int register_trigger_cmds(void);
 extern void clear_event_triggers(struct trace_array *tr);
 
 enum {
     EVENT_TRIGGER_FL_PROBE      = BIT(0),
 };
 
 struct event_trigger_data {
     unsigned long           count;
     int             ref;
     int             flags;
     struct event_trigger_ops    *ops;
     struct event_command        *cmd_ops;
     struct event_filter __rcu   *filter;
     char                *filter_str;
     void                *private_data;
     bool                paused;
     bool                paused_tmp;
     struct list_head        list;
     char                *name;
     struct list_head        named_list;
     struct event_trigger_data   *named_data;
 };
 
 /* Avoid typos */
 #define ENABLE_EVENT_STR    "enable_event"
 #define DISABLE_EVENT_STR   "disable_event"
 #define ENABLE_HIST_STR     "enable_hist"
 #define DISABLE_HIST_STR    "disable_hist"
 
 struct enable_trigger_data {
     struct trace_event_file     *file;
     bool                enable;
     bool                hist;
 };
 
 extern int event_enable_trigger_print(struct seq_file *m,
                       struct event_trigger_data *data);
 extern void event_enable_trigger_free(struct event_trigger_data *data);
 extern int event_enable_trigger_parse(struct event_command *cmd_ops,
                       struct trace_event_file *file,
                       char *glob, char *cmd,
                       char *param_and_filter);
 extern int event_enable_register_trigger(char *glob,
                      struct event_trigger_data *data,
                      struct trace_event_file *file);
 extern void event_enable_unregister_trigger(char *glob,
                         struct event_trigger_data *test,
                         struct trace_event_file *file);
 extern void trigger_data_free(struct event_trigger_data *data);
 extern int event_trigger_init(struct event_trigger_data *data);
 extern int trace_event_trigger_enable_disable(struct trace_event_file *file,
                           int trigger_enable);
 extern void update_cond_flag(struct trace_event_file *file);
 extern int set_trigger_filter(char *filter_str,
                   struct event_trigger_data *trigger_data,
                   struct trace_event_file *file);
 extern struct event_trigger_data *find_named_trigger(const char *name);
 extern bool is_named_trigger(struct event_trigger_data *test);
 extern int save_named_trigger(const char *name,
                   struct event_trigger_data *data);
 extern void del_named_trigger(struct event_trigger_data *data);
 extern void pause_named_trigger(struct event_trigger_data *data);
 extern void unpause_named_trigger(struct event_trigger_data *data);
 extern void set_named_trigger_data(struct event_trigger_data *data,
                    struct event_trigger_data *named_data);
 extern struct event_trigger_data *
 get_named_trigger_data(struct event_trigger_data *data);
 extern int register_event_command(struct event_command *cmd);
 extern int unregister_event_command(struct event_command *cmd);
 extern int register_trigger_hist_enable_disable_cmds(void);
 extern bool event_trigger_check_remove(const char *glob);
 extern bool event_trigger_empty_param(const char *param);
 extern int event_trigger_separate_filter(char *param_and_filter, char **param,
                      char **filter, bool param_required);
 extern struct event_trigger_data *
 event_trigger_alloc(struct event_command *cmd_ops,
             char *cmd,
             char *param,
             void *private_data);
 extern int event_trigger_parse_num(char *trigger,
                    struct event_trigger_data *trigger_data);
 extern int event_trigger_set_filter(struct event_command *cmd_ops,
                     struct trace_event_file *file,
                     char *param,
                     struct event_trigger_data *trigger_data);
 extern void event_trigger_reset_filter(struct event_command *cmd_ops,
                        struct event_trigger_data *trigger_data);
 extern int event_trigger_register(struct event_command *cmd_ops,
                   struct trace_event_file *file,
                   char *glob,
                   struct event_trigger_data *trigger_data);
 extern void event_trigger_unregister(struct event_command *cmd_ops,
                      struct trace_event_file *file,
                      char *glob,
                      struct event_trigger_data *trigger_data);
 
 /**
  * struct event_trigger_ops - callbacks for trace event triggers
  *
  * The methods in this structure provide per-event trigger hooks for
  * various trigger operations.
  *
  * The @init and @free methods are used during trigger setup and
  * teardown, typically called from an event_command's @parse()
  * function implementation.
  *
  * The @print method is used to print the trigger spec.
  *
  * The @trigger method is the function that actually implements the
  * trigger and is called in the context of the triggering event
  * whenever that event occurs.
  *
  * All the methods below, except for @init() and @free(), must be
  * implemented.
  *
  * @trigger: The trigger 'probe' function called when the triggering
  *  event occurs.  The data passed into this callback is the data
  *  that was supplied to the event_command @reg() function that
  *  registered the trigger (see struct event_command) along with
  *  the trace record, rec.
  *
  * @init: An optional initialization function called for the trigger
  *  when the trigger is registered (via the event_command reg()
  *  function).  This can be used to perform per-trigger
  *  initialization such as incrementing a per-trigger reference
  *  count, for instance.  This is usually implemented by the
  *  generic utility function @event_trigger_init() (see
  *  trace_event_triggers.c).
  *
  * @free: An optional de-initialization function called for the
  *  trigger when the trigger is unregistered (via the
  *  event_command @reg() function).  This can be used to perform
  *  per-trigger de-initialization such as decrementing a
  *  per-trigger reference count and freeing corresponding trigger
  *  data, for instance.  This is usually implemented by the
  *  generic utility function @event_trigger_free() (see
  *  trace_event_triggers.c).
  *
  * @print: The callback function invoked to have the trigger print
  *  itself.  This is usually implemented by a wrapper function
  *  that calls the generic utility function @event_trigger_print()
  *  (see trace_event_triggers.c).
  */
 struct event_trigger_ops {
     void            (*trigger)(struct event_trigger_data *data,
                        struct trace_buffer *buffer,
                        void *rec,
                        struct ring_buffer_event *rbe);
     int         (*init)(struct event_trigger_data *data);
     void            (*free)(struct event_trigger_data *data);
     int         (*print)(struct seq_file *m,
                      struct event_trigger_data *data);
 };
 
 /**
  * struct event_command - callbacks and data members for event commands
  *
  * Event commands are invoked by users by writing the command name
  * into the 'trigger' file associated with a trace event.  The
  * parameters associated with a specific invocation of an event
  * command are used to create an event trigger instance, which is
  * added to the list of trigger instances associated with that trace
  * event.  When the event is hit, the set of triggers associated with
  * that event is invoked.
  *
  * The data members in this structure provide per-event command data
  * for various event commands.
  *
  * All the data members below, except for @post_trigger, must be set
  * for each event command.
  *
  * @name: The unique name that identifies the event command.  This is
  *  the name used when setting triggers via trigger files.
  *
  * @trigger_type: A unique id that identifies the event command
  *  'type'.  This value has two purposes, the first to ensure that
  *  only one trigger of the same type can be set at a given time
  *  for a particular event e.g. it doesn't make sense to have both
  *  a traceon and traceoff trigger attached to a single event at
  *  the same time, so traceon and traceoff have the same type
  *  though they have different names.  The @trigger_type value is
  *  also used as a bit value for deferring the actual trigger
  *  action until after the current event is finished.  Some
  *  commands need to do this if they themselves log to the trace
  *  buffer (see the @post_trigger() member below).  @trigger_type
  *  values are defined by adding new values to the trigger_type
  *  enum in include/linux/trace_events.h.
  *
  * @flags: See the enum event_command_flags below.
  *
  * All the methods below, except for @set_filter() and @unreg_all(),
  * must be implemented.
  *
  * @parse: The callback function responsible for parsing and
  *  registering the trigger written to the 'trigger' file by the
  *  user.  It allocates the trigger instance and registers it with
  *  the appropriate trace event.  It makes use of the other
  *  event_command callback functions to orchestrate this, and is
  *  usually implemented by the generic utility function
  *  @event_trigger_callback() (see trace_event_triggers.c).
  *
  * @reg: Adds the trigger to the list of triggers associated with the
  *  event, and enables the event trigger itself, after
  *  initializing it (via the event_trigger_ops @init() function).
  *  This is also where commands can use the @trigger_type value to
  *  make the decision as to whether or not multiple instances of
  *  the trigger should be allowed.  This is usually implemented by
  *  the generic utility function @register_trigger() (see
  *  trace_event_triggers.c).
  *
  * @unreg: Removes the trigger from the list of triggers associated
  *  with the event, and disables the event trigger itself, after
  *  initializing it (via the event_trigger_ops @free() function).
  *  This is usually implemented by the generic utility function
  *  @unregister_trigger() (see trace_event_triggers.c).
  *
  * @unreg_all: An optional function called to remove all the triggers
  *  from the list of triggers associated with the event.  Called
  *  when a trigger file is opened in truncate mode.
  *
  * @set_filter: An optional function called to parse and set a filter
  *  for the trigger.  If no @set_filter() method is set for the
  *  event command, filters set by the user for the command will be
  *  ignored.  This is usually implemented by the generic utility
  *  function @set_trigger_filter() (see trace_event_triggers.c).
  *
  * @get_trigger_ops: The callback function invoked to retrieve the
  *  event_trigger_ops implementation associated with the command.
  *  This callback function allows a single event_command to
  *  support multiple trigger implementations via different sets of
  *  event_trigger_ops, depending on the value of the @param
  *  string.
  */
 struct event_command {
     struct list_head    list;
     char            *name;
     enum event_trigger_type trigger_type;
     int         flags;
     int         (*parse)(struct event_command *cmd_ops,
                      struct trace_event_file *file,
                      char *glob, char *cmd,
                      char *param_and_filter);
     int         (*reg)(char *glob,
                        struct event_trigger_data *data,
                        struct trace_event_file *file);
     void            (*unreg)(char *glob,
                      struct event_trigger_data *data,
                      struct trace_event_file *file);
     void            (*unreg_all)(struct trace_event_file *file);
     int         (*set_filter)(char *filter_str,
                           struct event_trigger_data *data,
                           struct trace_event_file *file);
     struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
 };
 
 /**
  * enum event_command_flags - flags for struct event_command
  *
  * @POST_TRIGGER: A flag that says whether or not this command needs
  *  to have its action delayed until after the current event has
  *  been closed.  Some triggers need to avoid being invoked while
  *  an event is currently in the process of being logged, since
  *  the trigger may itself log data into the trace buffer.  Thus
  *  we make sure the current event is committed before invoking
  *  those triggers.  To do that, the trigger invocation is split
  *  in two - the first part checks the filter using the current
  *  trace record; if a command has the @post_trigger flag set, it
  *  sets a bit for itself in the return value, otherwise it
  *  directly invokes the trigger.  Once all commands have been
  *  either invoked or set their return flag, the current record is
  *  either committed or discarded.  At that point, if any commands
  *  have deferred their triggers, those commands are finally
  *  invoked following the close of the current event.  In other
  *  words, if the event_trigger_ops @func() probe implementation
  *  itself logs to the trace buffer, this flag should be set,
  *  otherwise it can be left unspecified.
  *
  * @NEEDS_REC: A flag that says whether or not this command needs
  *  access to the trace record in order to perform its function,
  *  regardless of whether or not it has a filter associated with
  *  it (filters make a trigger require access to the trace record
  *  but are not always present).
  */
 enum event_command_flags {
     EVENT_CMD_FL_POST_TRIGGER   = 1,
     EVENT_CMD_FL_NEEDS_REC      = 2,
 };
 
 static inline bool event_command_post_trigger(struct event_command *cmd_ops)
 {
     return cmd_ops->flags & EVENT_CMD_FL_POST_TRIGGER;
 }
 
 static inline bool event_command_needs_rec(struct event_command *cmd_ops)
 {
     return cmd_ops->flags & EVENT_CMD_FL_NEEDS_REC;
 }
 
 extern int trace_event_enable_disable(struct trace_event_file *file,
                       int enable, int soft_disable);
 extern int tracing_alloc_snapshot(void);
 extern void tracing_snapshot_cond(struct trace_array *tr, void *cond_data);
 extern int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data, cond_update_fn_t update);
 
 extern int tracing_snapshot_cond_disable(struct trace_array *tr);
 extern void *tracing_cond_snapshot_data(struct trace_array *tr);
 
 extern const char *__start___trace_bprintk_fmt[];
 extern const char *__stop___trace_bprintk_fmt[];
 
 extern const char *__start___tracepoint_str[];
 extern const char *__stop___tracepoint_str[];
 
 void trace_printk_control(bool enabled);
 void trace_printk_start_comm(void);
 int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
 int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
 
 /* Used from boot time tracer */
 extern int trace_set_options(struct trace_array *tr, char *option);
 extern int tracing_set_tracer(struct trace_array *tr, const char *buf);
 extern ssize_t tracing_resize_ring_buffer(struct trace_array *tr,
                       unsigned long size, int cpu_id);
 extern int tracing_set_cpumask(struct trace_array *tr,
                 cpumask_var_t tracing_cpumask_new);
 
 
 #define MAX_EVENT_NAME_LEN  64
 
 extern ssize_t trace_parse_run_command(struct file *file,
         const char __user *buffer, size_t count, loff_t *ppos,
         int (*createfn)(const char *));
 
 extern unsigned int err_pos(char *cmd, const char *str);
 extern void tracing_log_err(struct trace_array *tr,
                 const char *loc, const char *cmd,
                 const char **errs, u8 type, u16 pos);
 
 /*
  * Normal trace_printk() and friends allocates special buffers
  * to do the manipulation, as well as saves the print formats
  * into sections to display. But the trace infrastructure wants
  * to use these without the added overhead at the price of being
  * a bit slower (used mainly for warnings, where we don't care
  * about performance). The internal_trace_puts() is for such
  * a purpose.
  */
 #define internal_trace_puts(str) __trace_puts(_THIS_IP_, str, strlen(str))
 
 #undef FTRACE_ENTRY
 #define FTRACE_ENTRY(call, struct_name, id, tstruct, print) \
     extern struct trace_event_call                  \
     __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))
 #undef FTRACE_ENTRY_PACKED
 #define FTRACE_ENTRY_PACKED(call, struct_name, id, tstruct, print) \
     FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
 
 #include "trace_entries.h"
 
 #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER)
 int perf_ftrace_event_register(struct trace_event_call *call,
                    enum trace_reg type, void *data);
 #else
 #define perf_ftrace_event_register NULL
 #endif
 
 #ifdef CONFIG_FTRACE_SYSCALLS
 void init_ftrace_syscalls(void);
 const char *get_syscall_name(int syscall);
 #else
 static inline void init_ftrace_syscalls(void) { }
 static inline const char *get_syscall_name(int syscall)
 {
     return NULL;
 }
 #endif
 
 #ifdef CONFIG_EVENT_TRACING
 void trace_event_init(void);
 void trace_event_eval_update(struct trace_eval_map **map, int len);
 /* Used from boot time tracer */
 extern int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set);
 extern int trigger_process_regex(struct trace_event_file *file, char *buff);
 #else
 static inline void __init trace_event_init(void) { }
 static inline void trace_event_eval_update(struct trace_eval_map **map, int len) { }
 #endif
 
 #ifdef CONFIG_TRACER_SNAPSHOT
 void tracing_snapshot_instance(struct trace_array *tr);
 int tracing_alloc_snapshot_instance(struct trace_array *tr);
 #else
 static inline void tracing_snapshot_instance(struct trace_array *tr) { }
 static inline int tracing_alloc_snapshot_instance(struct trace_array *tr)
 {
     return 0;
 }
 #endif
 
 #ifdef CONFIG_PREEMPT_TRACER
 void tracer_preempt_on(unsigned long a0, unsigned long a1);
 void tracer_preempt_off(unsigned long a0, unsigned long a1);
 #else
 static inline void tracer_preempt_on(unsigned long a0, unsigned long a1) { }
 static inline void tracer_preempt_off(unsigned long a0, unsigned long a1) { }
 #endif
 #ifdef CONFIG_IRQSOFF_TRACER
 void tracer_hardirqs_on(unsigned long a0, unsigned long a1);
 void tracer_hardirqs_off(unsigned long a0, unsigned long a1);
 #else
 static inline void tracer_hardirqs_on(unsigned long a0, unsigned long a1) { }
 static inline void tracer_hardirqs_off(unsigned long a0, unsigned long a1) { }
 #endif
 
 extern struct trace_iterator *tracepoint_print_iter;
 
 /*
  * Reset the state of the trace_iterator so that it can read consumed data.
  * Normally, the trace_iterator is used for reading the data when it is not
  * consumed, and must retain state.
  */
 static __always_inline void trace_iterator_reset(struct trace_iterator *iter)
 {
     memset_startat(iter, 0, seq);
     iter->pos = -1;
 }
 
 /* Check the name is good for event/group/fields */
 static inline bool is_good_name(const char *name)
 {
     if (!isalpha(*name) && *name != '_')
         return false;
     while (*++name != '\0') {
         if (!isalpha(*name) && !isdigit(*name) && *name != '_')
             return false;
     }
     return true;
 }
 
 /* Convert certain expected symbols into '_' when generating event names */
 static inline void sanitize_event_name(char *name)
 {
     while (*name++ != '\0')
         if (*name == ':' || *name == '.')
             *name = '_';
 }
 
 /*
  * This is a generic way to read and write a u64 value from a file in tracefs.
  *
  * The value is stored on the variable pointed by *val. The value needs
  * to be at least *min and at most *max. The write is protected by an
  * existing *lock.
  */
 struct trace_min_max_param {
     struct mutex    *lock;
     u64     *val;
     u64     *min;
     u64     *max;
 };
 
 #define U64_STR_SIZE        24  /* 20 digits max */
 
 extern const struct file_operations trace_min_max_fops;
 
 #ifdef CONFIG_RV
 extern int rv_init_interface(void);
 #else
 static inline int rv_init_interface(void)
 {
     return 0;
 }
 #endif
 
 #endif /* _LINUX_KERNEL_TRACE_H */

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