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trace.h 19.59 KiB
#ifndef _LINUX_KERNEL_TRACE_H
#define _LINUX_KERNEL_TRACE_H
#include <linux/fs.h>
#include <asm/atomic.h>
#include <linux/sched.h>
#include <linux/clocksource.h>
#include <linux/ring_buffer.h>
#include <linux/mmiotrace.h>
#include <linux/ftrace.h>
#include <trace/boot.h>
#include <trace/kmemtrace.h>
#include <trace/power.h>
enum trace_type {
__TRACE_FIRST_TYPE = 0,
TRACE_FN,
TRACE_CTX,
TRACE_WAKE,
TRACE_STACK,
TRACE_PRINT,
TRACE_SPECIAL,
TRACE_MMIO_RW,
TRACE_MMIO_MAP,
TRACE_BRANCH,
TRACE_BOOT_CALL,
TRACE_BOOT_RET,
TRACE_GRAPH_RET,
TRACE_GRAPH_ENT,
TRACE_USER_STACK,
TRACE_HW_BRANCHES,
TRACE_KMEM_ALLOC,
TRACE_KMEM_FREE,
TRACE_POWER,
TRACE_BLK,
__TRACE_LAST_TYPE,
};
/*
* The trace entry - the most basic unit of tracing. This is what
* is printed in the end as a single line in the trace output, such as:
*
* bash-15816 [01] 235.197585: idle_cpu <- irq_enter
*/
struct trace_entry {
unsigned char type;
unsigned char flags;
unsigned char preempt_count;
int pid;
int tgid;
};
/*
* Function trace entry - function address and parent function addres:
*/
struct ftrace_entry {
struct trace_entry ent;
unsigned long ip;
unsigned long parent_ip;
};
/* Function call entry */
struct ftrace_graph_ent_entry {
struct trace_entry ent;
struct ftrace_graph_ent graph_ent;
};
/* Function return entry */struct ftrace_graph_ret_entry {
struct trace_entry ent;
struct ftrace_graph_ret ret;
};
extern struct tracer boot_tracer;
/*
* Context switch trace entry - which task (and prio) we switched from/to:
*/
struct ctx_switch_entry {
struct trace_entry ent;
unsigned int prev_pid;
unsigned char prev_prio;
unsigned char prev_state;
unsigned int next_pid;
unsigned char next_prio;
unsigned char next_state;
unsigned int next_cpu;
};
/*
* Special (free-form) trace entry:
*/
struct special_entry {
struct trace_entry ent;
unsigned long arg1;
unsigned long arg2;
unsigned long arg3;
};
/*
* Stack-trace entry:
*/
#define FTRACE_STACK_ENTRIES 8
struct stack_entry {
struct trace_entry ent;
unsigned long caller[FTRACE_STACK_ENTRIES];
};
struct userstack_entry {
struct trace_entry ent;
unsigned long caller[FTRACE_STACK_ENTRIES];
};
/*
* ftrace_printk entry:
*/
struct print_entry {
struct trace_entry ent;
unsigned long ip;
int depth;
char buf[];
};
#define TRACE_OLD_SIZE 88
struct trace_field_cont {
unsigned char type;
/* Temporary till we get rid of this completely */
char buf[TRACE_OLD_SIZE - 1];
};
struct trace_mmiotrace_rw {
struct trace_entry ent;
struct mmiotrace_rw rw;
};
struct trace_mmiotrace_map { struct trace_entry ent;
struct mmiotrace_map map;
};
struct trace_boot_call {
struct trace_entry ent;
struct boot_trace_call boot_call;
};
struct trace_boot_ret {
struct trace_entry ent;
struct boot_trace_ret boot_ret;
};
#define TRACE_FUNC_SIZE 30
#define TRACE_FILE_SIZE 20
struct trace_branch {
struct trace_entry ent;
unsigned line;
char func[TRACE_FUNC_SIZE+1];
char file[TRACE_FILE_SIZE+1];
char correct;
};
struct hw_branch_entry {
struct trace_entry ent;
u64 from;
u64 to;
};
struct trace_power {
struct trace_entry ent;
struct power_trace state_data;
};
struct kmemtrace_alloc_entry {
struct trace_entry ent;
enum kmemtrace_type_id type_id;
unsigned long call_site;
const void *ptr;
size_t bytes_req;
size_t bytes_alloc;
gfp_t gfp_flags;
int node;
};
struct kmemtrace_free_entry {
struct trace_entry ent;
enum kmemtrace_type_id type_id;
unsigned long call_site;
const void *ptr;
};
/*
* 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_RESCED - reschedule is requested
* HARDIRQ - inside an interrupt handler
* SOFTIRQ - inside a softirq handler
*/
enum trace_flag_type {
TRACE_FLAG_IRQS_OFF = 0x01,
TRACE_FLAG_IRQS_NOSUPPORT = 0x02,
TRACE_FLAG_NEED_RESCHED = 0x04,
TRACE_FLAG_HARDIRQ = 0x08,
TRACE_FLAG_SOFTIRQ = 0x10,
};
#define TRACE_BUF_SIZE 1024
/*
* 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;
/* these fields get copied into max-trace: */
unsigned long trace_idx;
unsigned long overrun;
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;
cycle_t preempt_timestamp;
pid_t pid;
uid_t uid;
char comm[TASK_COMM_LEN];
};
struct trace_iterator;
/*
* 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 ring_buffer *buffer;
unsigned long entries;
int cpu;
cycle_t time_start;
struct task_struct *waiter;
struct trace_array_cpu *data[NR_CPUS];
};
#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 special_entry, 0); \
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_boot_call, TRACE_BOOT_CALL);\
IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\
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 hw_branch_entry, TRACE_HW_BRANCHES);\
IF_ASSIGN(var, ent, struct trace_power, TRACE_POWER); \
IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry, \
TRACE_KMEM_ALLOC); \
IF_ASSIGN(var, ent, struct kmemtrace_free_entry, \
TRACE_KMEM_FREE); \
__ftrace_bad_type(); \
} while (0)
/* Return values for print_line callback */
enum print_line_t {
TRACE_TYPE_PARTIAL_LINE = 0, /* Retry after flushing the seq */
TRACE_TYPE_HANDLED = 1,
TRACE_TYPE_UNHANDLED = 2, /* Relay to other output functions */
TRACE_TYPE_NO_CONSUME = 3 /* Handled but ask to not consume */
};
/*
* 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 tracer - a specific tracer and its callbacks to interact with debugfs
* @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)
* @open: called when the trace file is opened
* @pipe_open: called when the trace_pipe file is opened
* @wait_pipe: override how the user waits for traces on trace_pipe
* @close: called when the trace 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);
void (*open)(struct trace_iterator *iter);
void (*pipe_open)(struct trace_iterator *iter);
void (*wait_pipe)(struct trace_iterator *iter);
void (*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)(u32 old_flags, u32 bit, int set);
struct tracer *next;
int print_max;
struct tracer_flags *flags;
struct tracer_stat *stats;
};
struct trace_seq {
unsigned char buffer[PAGE_SIZE];
unsigned int len;
unsigned int readpos;
};
#define TRACE_PIPE_ALL_CPU -1
/*
* Trace iterator - used by printout routines who present trace
* results to users and which routines might sleep, etc:
*/
struct trace_iterator {
struct trace_array *tr;
struct tracer *trace;
void *private;
int cpu_file;
struct mutex mutex;
struct ring_buffer_iter *buffer_iter[NR_CPUS];
/* The below is zeroed out in pipe_read */
struct trace_seq seq;
struct trace_entry *ent;
int cpu;
u64 ts;
unsigned long iter_flags;
loff_t pos;
long idx;
cpumask_var_t started;
};
int tracer_init(struct tracer *t, struct trace_array *tr);
int tracing_is_enabled(void);
void trace_wake_up(void);
void tracing_reset(struct trace_array *tr, int cpu);
void tracing_reset_online_cpus(struct trace_array *tr);
int tracing_open_generic(struct inode *inode, struct file *filp);
struct dentry *tracing_init_dentry(void);
void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
struct ring_buffer_event;
struct ring_buffer_event *trace_buffer_lock_reserve(struct trace_array *tr,
unsigned char type,
unsigned long len,
unsigned long flags,
int pc);
void trace_buffer_unlock_commit(struct trace_array *tr,
struct ring_buffer_event *event,
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 tracing_generic_entry_update(struct trace_entry *entry,
unsigned long flags,
int pc);
void default_wait_pipe(struct trace_iterator *iter);
void poll_wait_pipe(struct trace_iterator *iter);
void ftrace(struct trace_array *tr,
struct trace_array_cpu *data,
unsigned long ip,
unsigned long parent_ip,
unsigned long flags, int pc);
void tracing_sched_switch_trace(struct trace_array *tr,
struct task_struct *prev,
struct task_struct *next,
unsigned long flags, int pc);
void tracing_record_cmdline(struct task_struct *tsk);
void tracing_sched_wakeup_trace(struct trace_array *tr,
struct task_struct *wakee,
struct task_struct *cur,
unsigned long flags, int pc);
void trace_special(struct trace_array *tr,
struct trace_array_cpu *data,
unsigned long arg1,
unsigned long arg2,
unsigned long arg3, int pc);
void trace_function(struct trace_array *tr,
unsigned long ip,
unsigned long parent_ip,
unsigned long flags, int pc);
void trace_graph_return(struct ftrace_graph_ret *trace);
int trace_graph_entry(struct ftrace_graph_ent *trace);
void tracing_start_cmdline_record(void);
void tracing_stop_cmdline_record(void);
void tracing_sched_switch_assign_trace(struct trace_array *tr);
void tracing_stop_sched_switch_record(void);
void tracing_start_sched_switch_record(void);int register_tracer(struct tracer *type);
void unregister_tracer(struct tracer *type);
extern unsigned long nsecs_to_usecs(unsigned long nsecs);
extern unsigned long tracing_max_latency;
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 __trace_stack(struct trace_array *tr,
unsigned long flags,
int skip, int pc);
extern cycle_t ftrace_now(int cpu);
#ifdef CONFIG_CONTEXT_SWITCH_TRACER
typedef void
(*tracer_switch_func_t)(void *private,
void *__rq,
struct task_struct *prev,
struct task_struct *next);
struct tracer_switch_ops {
tracer_switch_func_t func;
void *private;
struct tracer_switch_ops *next;
};
#endif /* CONFIG_CONTEXT_SWITCH_TRACER */
extern char *trace_find_cmdline(int pid);
#ifdef CONFIG_DYNAMIC_FTRACE
extern unsigned long ftrace_update_tot_cnt;
#define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
extern int DYN_FTRACE_TEST_NAME(void);
#endif
#ifdef CONFIG_FTRACE_STARTUP_TEST
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_sysprof(struct tracer *trace,
struct trace_array *tr);
extern int trace_selftest_startup_branch(struct tracer *trace,
struct trace_array *tr);
#endif /* CONFIG_FTRACE_STARTUP_TEST */
extern void *head_page(struct trace_array_cpu *data);
extern long ns2usecs(cycle_t nsec);
extern int
trace_vprintk(unsigned long ip, int depth, const char *fmt, va_list args);
extern unsigned long trace_flags;
/* Standard output formatting function used for function return traces */
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
extern enum print_line_t print_graph_function(struct trace_iterator *iter);
#ifdef CONFIG_DYNAMIC_FTRACE
/* TODO: make this variable */
#define FTRACE_GRAPH_MAX_FUNCS 32
extern int ftrace_graph_count;
extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
static inline int ftrace_graph_addr(unsigned long addr)
{
int i;
if (!ftrace_graph_count || test_tsk_trace_graph(current))
return 1;
for (i = 0; i < ftrace_graph_count; i++) {
if (addr == ftrace_graph_funcs[i])
return 1;
}
return 0;
}
#else
static inline int ftrace_trace_addr(unsigned long addr)
{
return 1;
}
static inline int ftrace_graph_addr(unsigned long addr)
{
return 1;
}
#endif /* CONFIG_DYNAMIC_FTRACE */
#else /* CONFIG_FUNCTION_GRAPH_TRACER */
static inline enum print_line_t
print_graph_function(struct trace_iterator *iter)
{
return TRACE_TYPE_UNHANDLED;
}
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
extern struct pid *ftrace_pid_trace;
static inline int ftrace_trace_task(struct task_struct *task)
{
if (!ftrace_pid_trace)
return 1;
return test_tsk_trace_trace(task);
}
/*
* 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.
*/
enum trace_iterator_flags {
TRACE_ITER_PRINT_PARENT = 0x01,
TRACE_ITER_SYM_OFFSET = 0x02,
TRACE_ITER_SYM_ADDR = 0x04,
TRACE_ITER_VERBOSE = 0x08,
TRACE_ITER_RAW = 0x10,
TRACE_ITER_HEX = 0x20,
TRACE_ITER_BIN = 0x40,
TRACE_ITER_BLOCK = 0x80,
TRACE_ITER_STACKTRACE = 0x100, TRACE_ITER_SCHED_TREE = 0x200,
TRACE_ITER_PRINTK = 0x400,
TRACE_ITER_PREEMPTONLY = 0x800,
TRACE_ITER_BRANCH = 0x1000,
TRACE_ITER_ANNOTATE = 0x2000,
TRACE_ITER_USERSTACKTRACE = 0x4000,
TRACE_ITER_SYM_USEROBJ = 0x8000,
TRACE_ITER_PRINTK_MSGONLY = 0x10000,
TRACE_ITER_CONTEXT_INFO = 0x20000 /* Print pid/cpu/time */
};
/*
* 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;
/**
* ftrace_preempt_disable - disable preemption scheduler safe
*
* When tracing can happen inside the scheduler, there exists
* cases that the tracing might happen before the need_resched
* flag is checked. If this happens and the tracer calls
* preempt_enable (after a disable), a schedule might take place
* causing an infinite recursion.
*
* To prevent this, we read the need_resched flag before
* disabling preemption. When we want to enable preemption we
* check the flag, if it is set, then we call preempt_enable_no_resched.
* Otherwise, we call preempt_enable.
*
* The rational for doing the above is that if need_resched is set
* and we have yet to reschedule, we are either in an atomic location
* (where we do not need to check for scheduling) or we are inside
* the scheduler and do not want to resched.
*/
static inline int ftrace_preempt_disable(void)
{
int resched;
resched = need_resched();
preempt_disable_notrace();
return resched;
}
/**
* ftrace_preempt_enable - enable preemption scheduler safe
* @resched: the return value from ftrace_preempt_disable
*
* This is a scheduler safe way to enable preemption and not miss
* any preemption checks. The disabled saved the state of preemption.
* If resched is set, then we are either inside an atomic or
* are inside the scheduler (we would have already scheduled
* otherwise). In this case, we do not want to call normal
* preempt_enable, but preempt_enable_no_resched instead.
*/
static inline void ftrace_preempt_enable(int resched)
{
if (resched)
preempt_enable_no_resched_notrace();
else
preempt_enable_notrace();
}
#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 (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 */
#endif /* _LINUX_KERNEL_TRACE_H */