blob: 919d9d07686f5bcaad65699f400748a4b4db8a5e [file] [log] [blame]
#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/hw_breakpoint.h>
#include <linux/trace_seq.h>
#include <linux/trace_events.h>
#include <linux/compiler.h>
#include <linux/trace_seq.h>
#include <asm/unistd.h> /* For NR_SYSCALLS */
#include <asm/syscall.h> /* some archs define it here */
enum trace_type {
#undef __field
#define __field(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 __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 F_STRUCT
#define F_STRUCT(args...) args
#define FTRACE_ENTRY(name, struct_name, id, tstruct, print, filter) \
struct struct_name { \
struct trace_entry ent; \
tstruct \
#define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk, filter)
#define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print, \
filter, regfn) \
FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
#include "trace_entries.h"
* 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 kretprobe_trace_entry_head {
struct trace_entry ent;
unsigned long func;
unsigned long ret_ip;
* trace_flag_type is an enumeration that holds different
* states when a trace occurs. These are:
* IRQS_OFF - interrupts were disabled
* IRQS_NOSUPPORT - arch does not support irqs_disabled_flags
* NEED_RESCHED - reschedule is requested
* HARDIRQ - inside an interrupt handler
* SOFTIRQ - inside a softirq handler
enum trace_flag_type {
#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;
cycle_t preempt_timestamp;
pid_t pid;
kuid_t uid;
char comm[TASK_COMM_LEN];
bool ignore_pid;
struct tracer;
struct trace_option_dentry;
struct trace_buffer {
struct trace_array *tr;
struct ring_buffer *buffer;
struct trace_array_cpu __percpu *data;
cycle_t time_start;
int cpu;
struct trace_options {
struct tracer *tracer;
struct trace_option_dentry *topts;
struct trace_pid_list {
unsigned int nr_pids;
int order;
pid_t *pids;
* 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 trace_buffer trace_buffer;
* 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 trace_buffer
* When a snapshot is taken, the buffer of the max_buffer is swapped
* with the buffer of the trace_buffer and the buffers are reset for
* the trace_buffer so the tracing can continue.
struct trace_buffer max_buffer;
bool allocated_snapshot;
unsigned long max_latency;
struct trace_pid_list __rcu *filtered_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
arch_spinlock_t max_lock;
int buffer_disabled;
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];
int stop_count;
int clock_id;
int nr_topts;
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 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;
cpumask_var_t tracing_cpumask; /* only trace on set CPUs */
int ref;
struct ftrace_ops *ops;
/* function tracing enabled */
int function_enabled;
enum {
extern struct list_head ftrace_trace_arrays;
extern struct mutex trace_types_lock;
extern int trace_array_get(struct trace_array *tr);
extern void trace_array_put(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);
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 && (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 trace_mmiotrace_rw, \
IF_ASSIGN(var, ent, struct trace_mmiotrace_map, \
IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry, \
IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry, \
__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;
/* 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_enabled)
* @stop: called when tracing is paused (echo 0 > tracing_enabled)
* @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);
int (*selftest)(struct tracer *trace,
struct trace_array *tr);
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;
int ref;
bool print_max;
bool allow_instances;
bool use_max_tr;
/* Only current can touch trace_recursion */
* For function tracing recursion:
* The order of these bits are important.
* When function tracing occurs, the following steps are made:
* If arch does not support a ftrace feature:
* call internal function (uses INTERNAL bits) which calls...
* If callback is registered to the "global" list, the list
* function is called and recursion checks the GLOBAL bits.
* then this function calls...
* The function callback, which can use the FTRACE bits to
* check for recursion.
* Now if the arch does not suppport a feature, and it calls
* the global list function which calls the ftrace callback
* all three of these steps will do a recursion protection.
* There's no reason to do one if the previous caller already
* did. The recursion that we are protecting against will
* go through the same steps again.
* To prevent the multiple recursion checks, if a recursion
* bit is set that is higher than the MAX bit of the current
* check, then we know that the check was made by the previous
* caller, and we can skip the current check.
enum {
/* Start of function recursion bits */
/* INTERNAL_BITs must be greater than FTRACE_BITs */
* Abuse of the trace_recursion.
* As we need a way to maintain state if we are tracing the function
* graph in irq because we want to trace a particular function that
* was called in irq context but we have irq tracing off. Since this
* can only be modified by current, we can reuse trace_recursion.
#define trace_recursion_set(bit) do { (current)->trace_recursion |= (1<<(bit)); } while (0)
#define trace_recursion_clear(bit) do { (current)->trace_recursion &= ~(1<<(bit)); } while (0)
#define trace_recursion_test(bit) ((current)->trace_recursion & (1<<(bit)))
static __always_inline int trace_get_context_bit(void)
int bit;
if (in_interrupt()) {
if (in_nmi())
bit = 0;
else if (in_irq())
bit = 1;
bit = 2;
} else
bit = 3;
return bit;
static __always_inline int trace_test_and_set_recursion(int start, int max)
unsigned int val = current->trace_recursion;
int bit;
/* A previous recursion check was made */
if ((val & TRACE_CONTEXT_MASK) > max)
return 0;
bit = trace_get_context_bit() + start;
if (unlikely(val & (1 << bit)))
return -1;
val |= 1 << bit;
current->trace_recursion = val;
return bit;
static __always_inline void trace_clear_recursion(int bit)
unsigned int val = current->trace_recursion;
if (!bit)
bit = 1 << bit;
val &= ~bit;
current->trace_recursion = val;
static inline struct ring_buffer_iter *
trace_buffer_iter(struct trace_iterator *iter, int cpu)
if (iter->buffer_iter && iter->buffer_iter[cpu])
return iter->buffer_iter[cpu];
return NULL;
int tracer_init(struct tracer *t, struct trace_array *tr);
int tracing_is_enabled(void);
void tracing_reset(struct trace_buffer *buf, int cpu);
void tracing_reset_online_cpus(struct trace_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);
bool tracing_is_disabled(void);
struct dentry *trace_create_file(const char *name,
umode_t mode,
struct dentry *parent,
void *data,
const struct file_operations *fops);
struct dentry *tracing_init_dentry(void);
struct ring_buffer_event;
struct ring_buffer_event *
trace_buffer_lock_reserve(struct ring_buffer *buffer,
int type,
unsigned long len,
unsigned long flags,
int pc);
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 __buffer_unlock_commit(struct ring_buffer *buffer,
struct ring_buffer_event *event);
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);
void trace_function(struct trace_array *tr,
unsigned long ip,
unsigned long parent_ip,
unsigned long flags, int pc);
void trace_graph_function(struct trace_array *tr,
unsigned long ip,
unsigned long parent_ip,
unsigned long flags, int pc);
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);
int trace_empty(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);
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;
void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
void update_max_tr_single(struct trace_array *tr,
struct task_struct *tsk, int cpu);
void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags,
int pc);
void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
int pc);
static inline void ftrace_trace_userstack(struct ring_buffer *buffer,
unsigned long flags, int pc)
static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
int skip, int pc)
extern cycle_t ftrace_now(int cpu);
extern void trace_find_cmdline(int pid, char comm[]);
extern unsigned long ftrace_update_tot_cnt;
#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;
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_sched_switch(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
/* Tracers are seldom changed. Optimize when selftests are disabled. */
#define __tracer_data __read_mostly
extern void *head_page(struct trace_array_cpu *data);
extern unsigned long long ns2usecs(cycle_t 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(struct trace_array *tr,
unsigned long ip, const char *fmt, ...);
int trace_array_printk_buf(struct ring_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);
/* Standard output formatting function used for function return traces */
/* Flag options */
extern void ftrace_graph_sleep_time_control(bool enable);
extern void ftrace_graph_graph_time_control(bool enable);
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 long flags, int pc);
extern void __trace_graph_return(struct trace_array *tr,
struct ftrace_graph_ret *trace,
unsigned long flags, int pc);
/* TODO: make this variable */
extern int ftrace_graph_count;
extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
extern int ftrace_graph_notrace_count;
extern unsigned long ftrace_graph_notrace_funcs[FTRACE_GRAPH_MAX_FUNCS];
static inline int ftrace_graph_addr(unsigned long addr)
int i;
if (!ftrace_graph_count)
return 1;
for (i = 0; i < ftrace_graph_count; i++) {
if (addr == ftrace_graph_funcs[i]) {
* 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_irq())
return 1;
return 0;
static inline int ftrace_graph_notrace_addr(unsigned long addr)
int i;
if (!ftrace_graph_notrace_count)
return 0;
for (i = 0; i < ftrace_graph_notrace_count; i++) {
if (addr == ftrace_graph_notrace_funcs[i])
return 1;
return 0;
static inline int ftrace_graph_addr(unsigned long addr)
return 1;
static inline int ftrace_graph_notrace_addr(unsigned long addr)
return 0;
static inline enum print_line_t
print_graph_function_flags(struct trace_iterator *iter, u32 flags)
extern struct list_head ftrace_pids;
extern bool ftrace_filter_param __initdata;
static inline int ftrace_trace_task(struct task_struct *task)
if (list_empty(&ftrace_pids))
return 1;
return test_tsk_trace_trace(task);
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);
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);
int using_ftrace_ops_list_func(void);
static inline int ftrace_trace_task(struct task_struct *task)
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 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) { }
/* ftace_func_t type is not defined, use macro instead of static inline */
#define ftrace_init_array_ops(tr, func) do { } while (0)
void ftrace_create_filter_files(struct ftrace_ops *ops,
struct dentry *parent);
void ftrace_destroy_filter_files(struct ftrace_ops *ops);
* 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)
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.
# define FGRAPH_FLAGS \
C(DISPLAY_GRAPH, "display-graph"),
# define BRANCH_FLAGS \
C(BRANCH, "branch"),
C(FUNCTION, "function-trace"),
# define STACK_FLAGS \
C(STACKTRACE, "stacktrace"),
# define STACK_FLAGS
* 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(OVERWRITE, "overwrite"), \
C(STOP_ON_FREE, "disable_on_free"), \
C(IRQ_INFO, "irq-info"), \
C(MARKERS, "markers"), \
* 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 {
/* Make sure we don't go more than we have bits for */
* 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.
extern struct tracer nop_trace;
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 */
static inline int trace_branch_enable(struct trace_array *tr)
return 0;
static inline void trace_branch_disable(void)
/* 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 event_filter {
int n_preds; /* Number assigned */
int a_preds; /* allocated */
struct filter_pred *preds;
struct filter_pred *root;
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;
#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 {
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;
unsigned short index;
unsigned short parent;
unsigned short left;
unsigned short right;
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_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 int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
extern int event_trace_del_tracer(struct trace_array *tr);
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 ACCESS_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 int register_trigger_cmds(void);
extern void clear_event_triggers(struct trace_array *tr);
struct event_trigger_data {
unsigned long count;
int ref;
struct event_trigger_ops *ops;
struct event_command *cmd_ops;
struct event_filter __rcu *filter;
char *filter_str;
void *private_data;
struct list_head list;
* struct event_trigger_ops - callbacks for trace event triggers
* The methods in this structure provide per-event trigger hooks for
* various trigger operations.
* All the methods below, except for @init() and @free(), must be
* implemented.
* @func: 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).
* @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 (*func)(struct event_trigger_data *data);
int (*init)(struct event_trigger_ops *ops,
struct event_trigger_data *data);
void (*free)(struct event_trigger_ops *ops,
struct event_trigger_data *data);
int (*print)(struct seq_file *m,
struct event_trigger_ops *ops,
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.
* @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.
* All the methods below, except for @set_filter(), must be
* implemented.
* @func: 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).
* @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.
struct event_command {
struct list_head list;
char *name;
enum event_trigger_type trigger_type;
bool post_trigger;
int (*func)(struct event_command *cmd_ops,
struct trace_event_file *file,
char *glob, char *cmd, char *params);
int (*reg)(char *glob,
struct event_trigger_ops *ops,
struct event_trigger_data *data,
struct trace_event_file *file);
void (*unreg)(char *glob,
struct event_trigger_ops *ops,
struct event_trigger_data *data,
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);
extern int trace_event_enable_disable(struct trace_event_file *file,
int enable, int soft_disable);
extern int tracing_alloc_snapshot(void);
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_init_buffers(void);
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);
* 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))
#define FTRACE_ENTRY(call, struct_name, id, tstruct, print, filter) \
extern struct trace_event_call \
__aligned(4) event_##call;
#define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print, filter) \
FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print), \
#include "trace_entries.h"
int perf_ftrace_event_register(struct trace_event_call *call,
enum trace_reg type, void *data);
#define perf_ftrace_event_register NULL
void init_ftrace_syscalls(void);
static inline void init_ftrace_syscalls(void) { }
void trace_event_init(void);
void trace_event_enum_update(struct trace_enum_map **map, int len);
static inline void __init trace_event_init(void) { }
static inline void trace_event_enum_update(struct trace_enum_map **map, int len) { }
extern struct trace_iterator *tracepoint_print_iter;
#endif /* _LINUX_KERNEL_TRACE_H */