3821 lines
85 KiB
C
3821 lines
85 KiB
C
/*
|
|
* ring buffer based function tracer
|
|
*
|
|
* Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
|
|
* Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
|
|
*
|
|
* Originally taken from the RT patch by:
|
|
* Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
*
|
|
* Based on code from the latency_tracer, that is:
|
|
* Copyright (C) 2004-2006 Ingo Molnar
|
|
* Copyright (C) 2004 William Lee Irwin III
|
|
*/
|
|
#include <linux/utsrelease.h>
|
|
#include <linux/kallsyms.h>
|
|
#include <linux/seq_file.h>
|
|
#include <linux/notifier.h>
|
|
#include <linux/debugfs.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/hardirq.h>
|
|
#include <linux/linkage.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/ftrace.h>
|
|
#include <linux/module.h>
|
|
#include <linux/percpu.h>
|
|
#include <linux/kdebug.h>
|
|
#include <linux/ctype.h>
|
|
#include <linux/init.h>
|
|
#include <linux/poll.h>
|
|
#include <linux/gfp.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/kprobes.h>
|
|
#include <linux/seq_file.h>
|
|
#include <linux/writeback.h>
|
|
|
|
#include <linux/stacktrace.h>
|
|
#include <linux/ring_buffer.h>
|
|
#include <linux/irqflags.h>
|
|
|
|
#include "trace.h"
|
|
|
|
#define TRACE_BUFFER_FLAGS (RB_FL_OVERWRITE)
|
|
|
|
unsigned long __read_mostly tracing_max_latency = (cycle_t)ULONG_MAX;
|
|
unsigned long __read_mostly tracing_thresh;
|
|
|
|
/*
|
|
* We need to change this state when a selftest is running.
|
|
* A selftest will lurk into the ring-buffer to count the
|
|
* entries inserted during the selftest although some concurrent
|
|
* insertions into the ring-buffer such as ftrace_printk could occurred
|
|
* at the same time, giving false positive or negative results.
|
|
*/
|
|
static bool __read_mostly tracing_selftest_running;
|
|
|
|
/* For tracers that don't implement custom flags */
|
|
static struct tracer_opt dummy_tracer_opt[] = {
|
|
{ }
|
|
};
|
|
|
|
static struct tracer_flags dummy_tracer_flags = {
|
|
.val = 0,
|
|
.opts = dummy_tracer_opt
|
|
};
|
|
|
|
static int dummy_set_flag(u32 old_flags, u32 bit, int set)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Kill all tracing for good (never come back).
|
|
* It is initialized to 1 but will turn to zero if the initialization
|
|
* of the tracer is successful. But that is the only place that sets
|
|
* this back to zero.
|
|
*/
|
|
int tracing_disabled = 1;
|
|
|
|
static DEFINE_PER_CPU(local_t, ftrace_cpu_disabled);
|
|
|
|
static inline void ftrace_disable_cpu(void)
|
|
{
|
|
preempt_disable();
|
|
local_inc(&__get_cpu_var(ftrace_cpu_disabled));
|
|
}
|
|
|
|
static inline void ftrace_enable_cpu(void)
|
|
{
|
|
local_dec(&__get_cpu_var(ftrace_cpu_disabled));
|
|
preempt_enable();
|
|
}
|
|
|
|
static cpumask_t __read_mostly tracing_buffer_mask;
|
|
|
|
#define for_each_tracing_cpu(cpu) \
|
|
for_each_cpu_mask(cpu, tracing_buffer_mask)
|
|
|
|
/*
|
|
* ftrace_dump_on_oops - variable to dump ftrace buffer on oops
|
|
*
|
|
* If there is an oops (or kernel panic) and the ftrace_dump_on_oops
|
|
* is set, then ftrace_dump is called. This will output the contents
|
|
* of the ftrace buffers to the console. This is very useful for
|
|
* capturing traces that lead to crashes and outputing it to a
|
|
* serial console.
|
|
*
|
|
* It is default off, but you can enable it with either specifying
|
|
* "ftrace_dump_on_oops" in the kernel command line, or setting
|
|
* /proc/sys/kernel/ftrace_dump_on_oops to true.
|
|
*/
|
|
int ftrace_dump_on_oops;
|
|
|
|
static int tracing_set_tracer(char *buf);
|
|
|
|
static int __init set_ftrace(char *str)
|
|
{
|
|
tracing_set_tracer(str);
|
|
return 1;
|
|
}
|
|
__setup("ftrace", set_ftrace);
|
|
|
|
static int __init set_ftrace_dump_on_oops(char *str)
|
|
{
|
|
ftrace_dump_on_oops = 1;
|
|
return 1;
|
|
}
|
|
__setup("ftrace_dump_on_oops", set_ftrace_dump_on_oops);
|
|
|
|
long
|
|
ns2usecs(cycle_t nsec)
|
|
{
|
|
nsec += 500;
|
|
do_div(nsec, 1000);
|
|
return nsec;
|
|
}
|
|
|
|
cycle_t ftrace_now(int cpu)
|
|
{
|
|
u64 ts = ring_buffer_time_stamp(cpu);
|
|
ring_buffer_normalize_time_stamp(cpu, &ts);
|
|
return ts;
|
|
}
|
|
|
|
/*
|
|
* The global_trace is the descriptor that holds the tracing
|
|
* buffers for the live tracing. For each CPU, it contains
|
|
* a link list of pages that will store trace entries. The
|
|
* page descriptor of the pages in the memory is used to hold
|
|
* the link list by linking the lru item in the page descriptor
|
|
* to each of the pages in the buffer per CPU.
|
|
*
|
|
* For each active CPU there is a data field that holds the
|
|
* pages for the buffer for that CPU. Each CPU has the same number
|
|
* of pages allocated for its buffer.
|
|
*/
|
|
static struct trace_array global_trace;
|
|
|
|
static DEFINE_PER_CPU(struct trace_array_cpu, global_trace_cpu);
|
|
|
|
/*
|
|
* The max_tr is used to snapshot the global_trace when a maximum
|
|
* latency is reached. Some tracers will use this to store a maximum
|
|
* trace while it continues examining live traces.
|
|
*
|
|
* The buffers for the max_tr are set up the same as the global_trace.
|
|
* When a snapshot is taken, the link list of the max_tr is swapped
|
|
* with the link list of the global_trace and the buffers are reset for
|
|
* the global_trace so the tracing can continue.
|
|
*/
|
|
static struct trace_array max_tr;
|
|
|
|
static DEFINE_PER_CPU(struct trace_array_cpu, max_data);
|
|
|
|
/* tracer_enabled is used to toggle activation of a tracer */
|
|
static int tracer_enabled = 1;
|
|
|
|
/**
|
|
* tracing_is_enabled - return tracer_enabled status
|
|
*
|
|
* This function is used by other tracers to know the status
|
|
* of the tracer_enabled flag. Tracers may use this function
|
|
* to know if it should enable their features when starting
|
|
* up. See irqsoff tracer for an example (start_irqsoff_tracer).
|
|
*/
|
|
int tracing_is_enabled(void)
|
|
{
|
|
return tracer_enabled;
|
|
}
|
|
|
|
/* function tracing enabled */
|
|
int ftrace_function_enabled;
|
|
|
|
/*
|
|
* trace_buf_size is the size in bytes that is allocated
|
|
* for a buffer. Note, the number of bytes is always rounded
|
|
* to page size.
|
|
*
|
|
* This number is purposely set to a low number of 16384.
|
|
* If the dump on oops happens, it will be much appreciated
|
|
* to not have to wait for all that output. Anyway this can be
|
|
* boot time and run time configurable.
|
|
*/
|
|
#define TRACE_BUF_SIZE_DEFAULT 1441792UL /* 16384 * 88 (sizeof(entry)) */
|
|
|
|
static unsigned long trace_buf_size = TRACE_BUF_SIZE_DEFAULT;
|
|
|
|
/* trace_types holds a link list of available tracers. */
|
|
static struct tracer *trace_types __read_mostly;
|
|
|
|
/* current_trace points to the tracer that is currently active */
|
|
static struct tracer *current_trace __read_mostly;
|
|
|
|
/*
|
|
* max_tracer_type_len is used to simplify the allocating of
|
|
* buffers to read userspace tracer names. We keep track of
|
|
* the longest tracer name registered.
|
|
*/
|
|
static int max_tracer_type_len;
|
|
|
|
/*
|
|
* trace_types_lock is used to protect the trace_types list.
|
|
* This lock is also used to keep user access serialized.
|
|
* Accesses from userspace will grab this lock while userspace
|
|
* activities happen inside the kernel.
|
|
*/
|
|
static DEFINE_MUTEX(trace_types_lock);
|
|
|
|
/* trace_wait is a waitqueue for tasks blocked on trace_poll */
|
|
static DECLARE_WAIT_QUEUE_HEAD(trace_wait);
|
|
|
|
/* trace_flags holds trace_options default values */
|
|
unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK |
|
|
TRACE_ITER_ANNOTATE;
|
|
|
|
/**
|
|
* trace_wake_up - wake up tasks waiting for trace input
|
|
*
|
|
* Simply wakes up any task that is blocked on the trace_wait
|
|
* queue. These is used with trace_poll for tasks polling the trace.
|
|
*/
|
|
void trace_wake_up(void)
|
|
{
|
|
/*
|
|
* The runqueue_is_locked() can fail, but this is the best we
|
|
* have for now:
|
|
*/
|
|
if (!(trace_flags & TRACE_ITER_BLOCK) && !runqueue_is_locked())
|
|
wake_up(&trace_wait);
|
|
}
|
|
|
|
static int __init set_buf_size(char *str)
|
|
{
|
|
unsigned long buf_size;
|
|
int ret;
|
|
|
|
if (!str)
|
|
return 0;
|
|
ret = strict_strtoul(str, 0, &buf_size);
|
|
/* nr_entries can not be zero */
|
|
if (ret < 0 || buf_size == 0)
|
|
return 0;
|
|
trace_buf_size = buf_size;
|
|
return 1;
|
|
}
|
|
__setup("trace_buf_size=", set_buf_size);
|
|
|
|
unsigned long nsecs_to_usecs(unsigned long nsecs)
|
|
{
|
|
return nsecs / 1000;
|
|
}
|
|
|
|
/* These must match the bit postions in trace_iterator_flags */
|
|
static const char *trace_options[] = {
|
|
"print-parent",
|
|
"sym-offset",
|
|
"sym-addr",
|
|
"verbose",
|
|
"raw",
|
|
"hex",
|
|
"bin",
|
|
"block",
|
|
"stacktrace",
|
|
"sched-tree",
|
|
"ftrace_printk",
|
|
"ftrace_preempt",
|
|
"branch",
|
|
"annotate",
|
|
"userstacktrace",
|
|
"sym-userobj",
|
|
"printk-msg-only",
|
|
NULL
|
|
};
|
|
|
|
/*
|
|
* ftrace_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 raw_spinlock_t in order to help
|
|
* with performance when lockdep debugging is enabled.
|
|
*/
|
|
static raw_spinlock_t ftrace_max_lock =
|
|
(raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
|
|
|
|
/*
|
|
* Copy the new maximum trace into the separate maximum-trace
|
|
* structure. (this way the maximum trace is permanently saved,
|
|
* for later retrieval via /debugfs/tracing/latency_trace)
|
|
*/
|
|
static void
|
|
__update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
|
|
{
|
|
struct trace_array_cpu *data = tr->data[cpu];
|
|
|
|
max_tr.cpu = cpu;
|
|
max_tr.time_start = data->preempt_timestamp;
|
|
|
|
data = max_tr.data[cpu];
|
|
data->saved_latency = tracing_max_latency;
|
|
|
|
memcpy(data->comm, tsk->comm, TASK_COMM_LEN);
|
|
data->pid = tsk->pid;
|
|
data->uid = task_uid(tsk);
|
|
data->nice = tsk->static_prio - 20 - MAX_RT_PRIO;
|
|
data->policy = tsk->policy;
|
|
data->rt_priority = tsk->rt_priority;
|
|
|
|
/* record this tasks comm */
|
|
tracing_record_cmdline(current);
|
|
}
|
|
|
|
/**
|
|
* trace_seq_printf - sequence printing of trace information
|
|
* @s: trace sequence descriptor
|
|
* @fmt: printf format string
|
|
*
|
|
* The tracer may use either sequence operations or its own
|
|
* copy to user routines. To simplify formating of a trace
|
|
* trace_seq_printf is used to store strings into a special
|
|
* buffer (@s). Then the output may be either used by
|
|
* the sequencer or pulled into another buffer.
|
|
*/
|
|
int
|
|
trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
|
|
{
|
|
int len = (PAGE_SIZE - 1) - s->len;
|
|
va_list ap;
|
|
int ret;
|
|
|
|
if (!len)
|
|
return 0;
|
|
|
|
va_start(ap, fmt);
|
|
ret = vsnprintf(s->buffer + s->len, len, fmt, ap);
|
|
va_end(ap);
|
|
|
|
/* If we can't write it all, don't bother writing anything */
|
|
if (ret >= len)
|
|
return 0;
|
|
|
|
s->len += ret;
|
|
|
|
return len;
|
|
}
|
|
|
|
/**
|
|
* trace_seq_puts - trace sequence printing of simple string
|
|
* @s: trace sequence descriptor
|
|
* @str: simple string to record
|
|
*
|
|
* The tracer may use either the sequence operations or its own
|
|
* copy to user routines. This function records a simple string
|
|
* into a special buffer (@s) for later retrieval by a sequencer
|
|
* or other mechanism.
|
|
*/
|
|
static int
|
|
trace_seq_puts(struct trace_seq *s, const char *str)
|
|
{
|
|
int len = strlen(str);
|
|
|
|
if (len > ((PAGE_SIZE - 1) - s->len))
|
|
return 0;
|
|
|
|
memcpy(s->buffer + s->len, str, len);
|
|
s->len += len;
|
|
|
|
return len;
|
|
}
|
|
|
|
static int
|
|
trace_seq_putc(struct trace_seq *s, unsigned char c)
|
|
{
|
|
if (s->len >= (PAGE_SIZE - 1))
|
|
return 0;
|
|
|
|
s->buffer[s->len++] = c;
|
|
|
|
return 1;
|
|
}
|
|
|
|
static int
|
|
trace_seq_putmem(struct trace_seq *s, void *mem, size_t len)
|
|
{
|
|
if (len > ((PAGE_SIZE - 1) - s->len))
|
|
return 0;
|
|
|
|
memcpy(s->buffer + s->len, mem, len);
|
|
s->len += len;
|
|
|
|
return len;
|
|
}
|
|
|
|
#define MAX_MEMHEX_BYTES 8
|
|
#define HEX_CHARS (MAX_MEMHEX_BYTES*2 + 1)
|
|
|
|
static int
|
|
trace_seq_putmem_hex(struct trace_seq *s, void *mem, size_t len)
|
|
{
|
|
unsigned char hex[HEX_CHARS];
|
|
unsigned char *data = mem;
|
|
int i, j;
|
|
|
|
#ifdef __BIG_ENDIAN
|
|
for (i = 0, j = 0; i < len; i++) {
|
|
#else
|
|
for (i = len-1, j = 0; i >= 0; i--) {
|
|
#endif
|
|
hex[j++] = hex_asc_hi(data[i]);
|
|
hex[j++] = hex_asc_lo(data[i]);
|
|
}
|
|
hex[j++] = ' ';
|
|
|
|
return trace_seq_putmem(s, hex, j);
|
|
}
|
|
|
|
static int
|
|
trace_seq_path(struct trace_seq *s, struct path *path)
|
|
{
|
|
unsigned char *p;
|
|
|
|
if (s->len >= (PAGE_SIZE - 1))
|
|
return 0;
|
|
p = d_path(path, s->buffer + s->len, PAGE_SIZE - s->len);
|
|
if (!IS_ERR(p)) {
|
|
p = mangle_path(s->buffer + s->len, p, "\n");
|
|
if (p) {
|
|
s->len = p - s->buffer;
|
|
return 1;
|
|
}
|
|
} else {
|
|
s->buffer[s->len++] = '?';
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void
|
|
trace_seq_reset(struct trace_seq *s)
|
|
{
|
|
s->len = 0;
|
|
s->readpos = 0;
|
|
}
|
|
|
|
ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt)
|
|
{
|
|
int len;
|
|
int ret;
|
|
|
|
if (s->len <= s->readpos)
|
|
return -EBUSY;
|
|
|
|
len = s->len - s->readpos;
|
|
if (cnt > len)
|
|
cnt = len;
|
|
ret = copy_to_user(ubuf, s->buffer + s->readpos, cnt);
|
|
if (ret)
|
|
return -EFAULT;
|
|
|
|
s->readpos += len;
|
|
return cnt;
|
|
}
|
|
|
|
static void
|
|
trace_print_seq(struct seq_file *m, struct trace_seq *s)
|
|
{
|
|
int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len;
|
|
|
|
s->buffer[len] = 0;
|
|
seq_puts(m, s->buffer);
|
|
|
|
trace_seq_reset(s);
|
|
}
|
|
|
|
/**
|
|
* update_max_tr - snapshot all trace buffers from global_trace to max_tr
|
|
* @tr: tracer
|
|
* @tsk: the task with the latency
|
|
* @cpu: The cpu that initiated the trace.
|
|
*
|
|
* Flip the buffers between the @tr and the max_tr and record information
|
|
* about which task was the cause of this latency.
|
|
*/
|
|
void
|
|
update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
|
|
{
|
|
struct ring_buffer *buf = tr->buffer;
|
|
|
|
WARN_ON_ONCE(!irqs_disabled());
|
|
__raw_spin_lock(&ftrace_max_lock);
|
|
|
|
tr->buffer = max_tr.buffer;
|
|
max_tr.buffer = buf;
|
|
|
|
ftrace_disable_cpu();
|
|
ring_buffer_reset(tr->buffer);
|
|
ftrace_enable_cpu();
|
|
|
|
__update_max_tr(tr, tsk, cpu);
|
|
__raw_spin_unlock(&ftrace_max_lock);
|
|
}
|
|
|
|
/**
|
|
* update_max_tr_single - only copy one trace over, and reset the rest
|
|
* @tr - tracer
|
|
* @tsk - task with the latency
|
|
* @cpu - the cpu of the buffer to copy.
|
|
*
|
|
* Flip the trace of a single CPU buffer between the @tr and the max_tr.
|
|
*/
|
|
void
|
|
update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
|
|
{
|
|
int ret;
|
|
|
|
WARN_ON_ONCE(!irqs_disabled());
|
|
__raw_spin_lock(&ftrace_max_lock);
|
|
|
|
ftrace_disable_cpu();
|
|
|
|
ring_buffer_reset(max_tr.buffer);
|
|
ret = ring_buffer_swap_cpu(max_tr.buffer, tr->buffer, cpu);
|
|
|
|
ftrace_enable_cpu();
|
|
|
|
WARN_ON_ONCE(ret);
|
|
|
|
__update_max_tr(tr, tsk, cpu);
|
|
__raw_spin_unlock(&ftrace_max_lock);
|
|
}
|
|
|
|
/**
|
|
* register_tracer - register a tracer with the ftrace system.
|
|
* @type - the plugin for the tracer
|
|
*
|
|
* Register a new plugin tracer.
|
|
*/
|
|
int register_tracer(struct tracer *type)
|
|
{
|
|
struct tracer *t;
|
|
int len;
|
|
int ret = 0;
|
|
|
|
if (!type->name) {
|
|
pr_info("Tracer must have a name\n");
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* When this gets called we hold the BKL which means that
|
|
* preemption is disabled. Various trace selftests however
|
|
* need to disable and enable preemption for successful tests.
|
|
* So we drop the BKL here and grab it after the tests again.
|
|
*/
|
|
unlock_kernel();
|
|
mutex_lock(&trace_types_lock);
|
|
|
|
tracing_selftest_running = true;
|
|
|
|
for (t = trace_types; t; t = t->next) {
|
|
if (strcmp(type->name, t->name) == 0) {
|
|
/* already found */
|
|
pr_info("Trace %s already registered\n",
|
|
type->name);
|
|
ret = -1;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
if (!type->set_flag)
|
|
type->set_flag = &dummy_set_flag;
|
|
if (!type->flags)
|
|
type->flags = &dummy_tracer_flags;
|
|
else
|
|
if (!type->flags->opts)
|
|
type->flags->opts = dummy_tracer_opt;
|
|
|
|
#ifdef CONFIG_FTRACE_STARTUP_TEST
|
|
if (type->selftest) {
|
|
struct tracer *saved_tracer = current_trace;
|
|
struct trace_array *tr = &global_trace;
|
|
int i;
|
|
|
|
/*
|
|
* Run a selftest on this tracer.
|
|
* Here we reset the trace buffer, and set the current
|
|
* tracer to be this tracer. The tracer can then run some
|
|
* internal tracing to verify that everything is in order.
|
|
* If we fail, we do not register this tracer.
|
|
*/
|
|
for_each_tracing_cpu(i)
|
|
tracing_reset(tr, i);
|
|
|
|
current_trace = type;
|
|
/* the test is responsible for initializing and enabling */
|
|
pr_info("Testing tracer %s: ", type->name);
|
|
ret = type->selftest(type, tr);
|
|
/* the test is responsible for resetting too */
|
|
current_trace = saved_tracer;
|
|
if (ret) {
|
|
printk(KERN_CONT "FAILED!\n");
|
|
goto out;
|
|
}
|
|
/* Only reset on passing, to avoid touching corrupted buffers */
|
|
for_each_tracing_cpu(i)
|
|
tracing_reset(tr, i);
|
|
|
|
printk(KERN_CONT "PASSED\n");
|
|
}
|
|
#endif
|
|
|
|
type->next = trace_types;
|
|
trace_types = type;
|
|
len = strlen(type->name);
|
|
if (len > max_tracer_type_len)
|
|
max_tracer_type_len = len;
|
|
|
|
out:
|
|
tracing_selftest_running = false;
|
|
mutex_unlock(&trace_types_lock);
|
|
lock_kernel();
|
|
|
|
return ret;
|
|
}
|
|
|
|
void unregister_tracer(struct tracer *type)
|
|
{
|
|
struct tracer **t;
|
|
int len;
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
for (t = &trace_types; *t; t = &(*t)->next) {
|
|
if (*t == type)
|
|
goto found;
|
|
}
|
|
pr_info("Trace %s not registered\n", type->name);
|
|
goto out;
|
|
|
|
found:
|
|
*t = (*t)->next;
|
|
if (strlen(type->name) != max_tracer_type_len)
|
|
goto out;
|
|
|
|
max_tracer_type_len = 0;
|
|
for (t = &trace_types; *t; t = &(*t)->next) {
|
|
len = strlen((*t)->name);
|
|
if (len > max_tracer_type_len)
|
|
max_tracer_type_len = len;
|
|
}
|
|
out:
|
|
mutex_unlock(&trace_types_lock);
|
|
}
|
|
|
|
void tracing_reset(struct trace_array *tr, int cpu)
|
|
{
|
|
ftrace_disable_cpu();
|
|
ring_buffer_reset_cpu(tr->buffer, cpu);
|
|
ftrace_enable_cpu();
|
|
}
|
|
|
|
void tracing_reset_online_cpus(struct trace_array *tr)
|
|
{
|
|
int cpu;
|
|
|
|
tr->time_start = ftrace_now(tr->cpu);
|
|
|
|
for_each_online_cpu(cpu)
|
|
tracing_reset(tr, cpu);
|
|
}
|
|
|
|
#define SAVED_CMDLINES 128
|
|
static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1];
|
|
static unsigned map_cmdline_to_pid[SAVED_CMDLINES];
|
|
static char saved_cmdlines[SAVED_CMDLINES][TASK_COMM_LEN];
|
|
static int cmdline_idx;
|
|
static DEFINE_SPINLOCK(trace_cmdline_lock);
|
|
|
|
/* temporary disable recording */
|
|
atomic_t trace_record_cmdline_disabled __read_mostly;
|
|
|
|
static void trace_init_cmdlines(void)
|
|
{
|
|
memset(&map_pid_to_cmdline, -1, sizeof(map_pid_to_cmdline));
|
|
memset(&map_cmdline_to_pid, -1, sizeof(map_cmdline_to_pid));
|
|
cmdline_idx = 0;
|
|
}
|
|
|
|
static int trace_stop_count;
|
|
static DEFINE_SPINLOCK(tracing_start_lock);
|
|
|
|
/**
|
|
* ftrace_off_permanent - disable all ftrace code permanently
|
|
*
|
|
* This should only be called when a serious anomally has
|
|
* been detected. This will turn off the function tracing,
|
|
* ring buffers, and other tracing utilites. It takes no
|
|
* locks and can be called from any context.
|
|
*/
|
|
void ftrace_off_permanent(void)
|
|
{
|
|
tracing_disabled = 1;
|
|
ftrace_stop();
|
|
tracing_off_permanent();
|
|
}
|
|
|
|
/**
|
|
* tracing_start - quick start of the tracer
|
|
*
|
|
* If tracing is enabled but was stopped by tracing_stop,
|
|
* this will start the tracer back up.
|
|
*/
|
|
void tracing_start(void)
|
|
{
|
|
struct ring_buffer *buffer;
|
|
unsigned long flags;
|
|
|
|
if (tracing_disabled)
|
|
return;
|
|
|
|
spin_lock_irqsave(&tracing_start_lock, flags);
|
|
if (--trace_stop_count)
|
|
goto out;
|
|
|
|
if (trace_stop_count < 0) {
|
|
/* Someone screwed up their debugging */
|
|
WARN_ON_ONCE(1);
|
|
trace_stop_count = 0;
|
|
goto out;
|
|
}
|
|
|
|
|
|
buffer = global_trace.buffer;
|
|
if (buffer)
|
|
ring_buffer_record_enable(buffer);
|
|
|
|
buffer = max_tr.buffer;
|
|
if (buffer)
|
|
ring_buffer_record_enable(buffer);
|
|
|
|
ftrace_start();
|
|
out:
|
|
spin_unlock_irqrestore(&tracing_start_lock, flags);
|
|
}
|
|
|
|
/**
|
|
* tracing_stop - quick stop of the tracer
|
|
*
|
|
* Light weight way to stop tracing. Use in conjunction with
|
|
* tracing_start.
|
|
*/
|
|
void tracing_stop(void)
|
|
{
|
|
struct ring_buffer *buffer;
|
|
unsigned long flags;
|
|
|
|
ftrace_stop();
|
|
spin_lock_irqsave(&tracing_start_lock, flags);
|
|
if (trace_stop_count++)
|
|
goto out;
|
|
|
|
buffer = global_trace.buffer;
|
|
if (buffer)
|
|
ring_buffer_record_disable(buffer);
|
|
|
|
buffer = max_tr.buffer;
|
|
if (buffer)
|
|
ring_buffer_record_disable(buffer);
|
|
|
|
out:
|
|
spin_unlock_irqrestore(&tracing_start_lock, flags);
|
|
}
|
|
|
|
void trace_stop_cmdline_recording(void);
|
|
|
|
static void trace_save_cmdline(struct task_struct *tsk)
|
|
{
|
|
unsigned map;
|
|
unsigned idx;
|
|
|
|
if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT))
|
|
return;
|
|
|
|
/*
|
|
* It's not the end of the world if we don't get
|
|
* the lock, but we also don't want to spin
|
|
* nor do we want to disable interrupts,
|
|
* so if we miss here, then better luck next time.
|
|
*/
|
|
if (!spin_trylock(&trace_cmdline_lock))
|
|
return;
|
|
|
|
idx = map_pid_to_cmdline[tsk->pid];
|
|
if (idx >= SAVED_CMDLINES) {
|
|
idx = (cmdline_idx + 1) % SAVED_CMDLINES;
|
|
|
|
map = map_cmdline_to_pid[idx];
|
|
if (map <= PID_MAX_DEFAULT)
|
|
map_pid_to_cmdline[map] = (unsigned)-1;
|
|
|
|
map_pid_to_cmdline[tsk->pid] = idx;
|
|
|
|
cmdline_idx = idx;
|
|
}
|
|
|
|
memcpy(&saved_cmdlines[idx], tsk->comm, TASK_COMM_LEN);
|
|
|
|
spin_unlock(&trace_cmdline_lock);
|
|
}
|
|
|
|
char *trace_find_cmdline(int pid)
|
|
{
|
|
char *cmdline = "<...>";
|
|
unsigned map;
|
|
|
|
if (!pid)
|
|
return "<idle>";
|
|
|
|
if (pid > PID_MAX_DEFAULT)
|
|
goto out;
|
|
|
|
map = map_pid_to_cmdline[pid];
|
|
if (map >= SAVED_CMDLINES)
|
|
goto out;
|
|
|
|
cmdline = saved_cmdlines[map];
|
|
|
|
out:
|
|
return cmdline;
|
|
}
|
|
|
|
void tracing_record_cmdline(struct task_struct *tsk)
|
|
{
|
|
if (atomic_read(&trace_record_cmdline_disabled))
|
|
return;
|
|
|
|
trace_save_cmdline(tsk);
|
|
}
|
|
|
|
void
|
|
tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags,
|
|
int pc)
|
|
{
|
|
struct task_struct *tsk = current;
|
|
|
|
entry->preempt_count = pc & 0xff;
|
|
entry->pid = (tsk) ? tsk->pid : 0;
|
|
entry->tgid = (tsk) ? tsk->tgid : 0;
|
|
entry->flags =
|
|
#ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
|
|
(irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) |
|
|
#else
|
|
TRACE_FLAG_IRQS_NOSUPPORT |
|
|
#endif
|
|
((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) |
|
|
((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) |
|
|
(need_resched() ? TRACE_FLAG_NEED_RESCHED : 0);
|
|
}
|
|
|
|
void
|
|
trace_function(struct trace_array *tr, struct trace_array_cpu *data,
|
|
unsigned long ip, unsigned long parent_ip, unsigned long flags,
|
|
int pc)
|
|
{
|
|
struct ring_buffer_event *event;
|
|
struct ftrace_entry *entry;
|
|
unsigned long irq_flags;
|
|
|
|
/* If we are reading the ring buffer, don't trace */
|
|
if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
|
|
return;
|
|
|
|
event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
|
|
&irq_flags);
|
|
if (!event)
|
|
return;
|
|
entry = ring_buffer_event_data(event);
|
|
tracing_generic_entry_update(&entry->ent, flags, pc);
|
|
entry->ent.type = TRACE_FN;
|
|
entry->ip = ip;
|
|
entry->parent_ip = parent_ip;
|
|
ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
|
|
}
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
static void __trace_graph_entry(struct trace_array *tr,
|
|
struct trace_array_cpu *data,
|
|
struct ftrace_graph_ent *trace,
|
|
unsigned long flags,
|
|
int pc)
|
|
{
|
|
struct ring_buffer_event *event;
|
|
struct ftrace_graph_ent_entry *entry;
|
|
unsigned long irq_flags;
|
|
|
|
if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
|
|
return;
|
|
|
|
event = ring_buffer_lock_reserve(global_trace.buffer, sizeof(*entry),
|
|
&irq_flags);
|
|
if (!event)
|
|
return;
|
|
entry = ring_buffer_event_data(event);
|
|
tracing_generic_entry_update(&entry->ent, flags, pc);
|
|
entry->ent.type = TRACE_GRAPH_ENT;
|
|
entry->graph_ent = *trace;
|
|
ring_buffer_unlock_commit(global_trace.buffer, event, irq_flags);
|
|
}
|
|
|
|
static void __trace_graph_return(struct trace_array *tr,
|
|
struct trace_array_cpu *data,
|
|
struct ftrace_graph_ret *trace,
|
|
unsigned long flags,
|
|
int pc)
|
|
{
|
|
struct ring_buffer_event *event;
|
|
struct ftrace_graph_ret_entry *entry;
|
|
unsigned long irq_flags;
|
|
|
|
if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
|
|
return;
|
|
|
|
event = ring_buffer_lock_reserve(global_trace.buffer, sizeof(*entry),
|
|
&irq_flags);
|
|
if (!event)
|
|
return;
|
|
entry = ring_buffer_event_data(event);
|
|
tracing_generic_entry_update(&entry->ent, flags, pc);
|
|
entry->ent.type = TRACE_GRAPH_RET;
|
|
entry->ret = *trace;
|
|
ring_buffer_unlock_commit(global_trace.buffer, event, irq_flags);
|
|
}
|
|
#endif
|
|
|
|
void
|
|
ftrace(struct trace_array *tr, struct trace_array_cpu *data,
|
|
unsigned long ip, unsigned long parent_ip, unsigned long flags,
|
|
int pc)
|
|
{
|
|
if (likely(!atomic_read(&data->disabled)))
|
|
trace_function(tr, data, ip, parent_ip, flags, pc);
|
|
}
|
|
|
|
static void ftrace_trace_stack(struct trace_array *tr,
|
|
struct trace_array_cpu *data,
|
|
unsigned long flags,
|
|
int skip, int pc)
|
|
{
|
|
#ifdef CONFIG_STACKTRACE
|
|
struct ring_buffer_event *event;
|
|
struct stack_entry *entry;
|
|
struct stack_trace trace;
|
|
unsigned long irq_flags;
|
|
|
|
if (!(trace_flags & TRACE_ITER_STACKTRACE))
|
|
return;
|
|
|
|
event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
|
|
&irq_flags);
|
|
if (!event)
|
|
return;
|
|
entry = ring_buffer_event_data(event);
|
|
tracing_generic_entry_update(&entry->ent, flags, pc);
|
|
entry->ent.type = TRACE_STACK;
|
|
|
|
memset(&entry->caller, 0, sizeof(entry->caller));
|
|
|
|
trace.nr_entries = 0;
|
|
trace.max_entries = FTRACE_STACK_ENTRIES;
|
|
trace.skip = skip;
|
|
trace.entries = entry->caller;
|
|
|
|
save_stack_trace(&trace);
|
|
ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
|
|
#endif
|
|
}
|
|
|
|
void __trace_stack(struct trace_array *tr,
|
|
struct trace_array_cpu *data,
|
|
unsigned long flags,
|
|
int skip)
|
|
{
|
|
ftrace_trace_stack(tr, data, flags, skip, preempt_count());
|
|
}
|
|
|
|
static void ftrace_trace_userstack(struct trace_array *tr,
|
|
struct trace_array_cpu *data,
|
|
unsigned long flags, int pc)
|
|
{
|
|
#ifdef CONFIG_STACKTRACE
|
|
struct ring_buffer_event *event;
|
|
struct userstack_entry *entry;
|
|
struct stack_trace trace;
|
|
unsigned long irq_flags;
|
|
|
|
if (!(trace_flags & TRACE_ITER_USERSTACKTRACE))
|
|
return;
|
|
|
|
event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
|
|
&irq_flags);
|
|
if (!event)
|
|
return;
|
|
entry = ring_buffer_event_data(event);
|
|
tracing_generic_entry_update(&entry->ent, flags, pc);
|
|
entry->ent.type = TRACE_USER_STACK;
|
|
|
|
memset(&entry->caller, 0, sizeof(entry->caller));
|
|
|
|
trace.nr_entries = 0;
|
|
trace.max_entries = FTRACE_STACK_ENTRIES;
|
|
trace.skip = 0;
|
|
trace.entries = entry->caller;
|
|
|
|
save_stack_trace_user(&trace);
|
|
ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
|
|
#endif
|
|
}
|
|
|
|
void __trace_userstack(struct trace_array *tr,
|
|
struct trace_array_cpu *data,
|
|
unsigned long flags)
|
|
{
|
|
ftrace_trace_userstack(tr, data, flags, preempt_count());
|
|
}
|
|
|
|
static void
|
|
ftrace_trace_special(void *__tr, void *__data,
|
|
unsigned long arg1, unsigned long arg2, unsigned long arg3,
|
|
int pc)
|
|
{
|
|
struct ring_buffer_event *event;
|
|
struct trace_array_cpu *data = __data;
|
|
struct trace_array *tr = __tr;
|
|
struct special_entry *entry;
|
|
unsigned long irq_flags;
|
|
|
|
event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
|
|
&irq_flags);
|
|
if (!event)
|
|
return;
|
|
entry = ring_buffer_event_data(event);
|
|
tracing_generic_entry_update(&entry->ent, 0, pc);
|
|
entry->ent.type = TRACE_SPECIAL;
|
|
entry->arg1 = arg1;
|
|
entry->arg2 = arg2;
|
|
entry->arg3 = arg3;
|
|
ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
|
|
ftrace_trace_stack(tr, data, irq_flags, 4, pc);
|
|
ftrace_trace_userstack(tr, data, irq_flags, pc);
|
|
|
|
trace_wake_up();
|
|
}
|
|
|
|
void
|
|
__trace_special(void *__tr, void *__data,
|
|
unsigned long arg1, unsigned long arg2, unsigned long arg3)
|
|
{
|
|
ftrace_trace_special(__tr, __data, arg1, arg2, arg3, preempt_count());
|
|
}
|
|
|
|
void
|
|
tracing_sched_switch_trace(struct trace_array *tr,
|
|
struct trace_array_cpu *data,
|
|
struct task_struct *prev,
|
|
struct task_struct *next,
|
|
unsigned long flags, int pc)
|
|
{
|
|
struct ring_buffer_event *event;
|
|
struct ctx_switch_entry *entry;
|
|
unsigned long irq_flags;
|
|
|
|
event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
|
|
&irq_flags);
|
|
if (!event)
|
|
return;
|
|
entry = ring_buffer_event_data(event);
|
|
tracing_generic_entry_update(&entry->ent, flags, pc);
|
|
entry->ent.type = TRACE_CTX;
|
|
entry->prev_pid = prev->pid;
|
|
entry->prev_prio = prev->prio;
|
|
entry->prev_state = prev->state;
|
|
entry->next_pid = next->pid;
|
|
entry->next_prio = next->prio;
|
|
entry->next_state = next->state;
|
|
entry->next_cpu = task_cpu(next);
|
|
ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
|
|
ftrace_trace_stack(tr, data, flags, 5, pc);
|
|
ftrace_trace_userstack(tr, data, flags, pc);
|
|
}
|
|
|
|
void
|
|
tracing_sched_wakeup_trace(struct trace_array *tr,
|
|
struct trace_array_cpu *data,
|
|
struct task_struct *wakee,
|
|
struct task_struct *curr,
|
|
unsigned long flags, int pc)
|
|
{
|
|
struct ring_buffer_event *event;
|
|
struct ctx_switch_entry *entry;
|
|
unsigned long irq_flags;
|
|
|
|
event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
|
|
&irq_flags);
|
|
if (!event)
|
|
return;
|
|
entry = ring_buffer_event_data(event);
|
|
tracing_generic_entry_update(&entry->ent, flags, pc);
|
|
entry->ent.type = TRACE_WAKE;
|
|
entry->prev_pid = curr->pid;
|
|
entry->prev_prio = curr->prio;
|
|
entry->prev_state = curr->state;
|
|
entry->next_pid = wakee->pid;
|
|
entry->next_prio = wakee->prio;
|
|
entry->next_state = wakee->state;
|
|
entry->next_cpu = task_cpu(wakee);
|
|
ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
|
|
ftrace_trace_stack(tr, data, flags, 6, pc);
|
|
ftrace_trace_userstack(tr, data, flags, pc);
|
|
|
|
trace_wake_up();
|
|
}
|
|
|
|
void
|
|
ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3)
|
|
{
|
|
struct trace_array *tr = &global_trace;
|
|
struct trace_array_cpu *data;
|
|
unsigned long flags;
|
|
int cpu;
|
|
int pc;
|
|
|
|
if (tracing_disabled)
|
|
return;
|
|
|
|
pc = preempt_count();
|
|
local_irq_save(flags);
|
|
cpu = raw_smp_processor_id();
|
|
data = tr->data[cpu];
|
|
|
|
if (likely(atomic_inc_return(&data->disabled) == 1))
|
|
ftrace_trace_special(tr, data, arg1, arg2, arg3, pc);
|
|
|
|
atomic_dec(&data->disabled);
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
#ifdef CONFIG_FUNCTION_TRACER
|
|
static void
|
|
function_trace_call_preempt_only(unsigned long ip, unsigned long parent_ip)
|
|
{
|
|
struct trace_array *tr = &global_trace;
|
|
struct trace_array_cpu *data;
|
|
unsigned long flags;
|
|
long disabled;
|
|
int cpu, resched;
|
|
int pc;
|
|
|
|
if (unlikely(!ftrace_function_enabled))
|
|
return;
|
|
|
|
pc = preempt_count();
|
|
resched = ftrace_preempt_disable();
|
|
local_save_flags(flags);
|
|
cpu = raw_smp_processor_id();
|
|
data = tr->data[cpu];
|
|
disabled = atomic_inc_return(&data->disabled);
|
|
|
|
if (likely(disabled == 1))
|
|
trace_function(tr, data, ip, parent_ip, flags, pc);
|
|
|
|
atomic_dec(&data->disabled);
|
|
ftrace_preempt_enable(resched);
|
|
}
|
|
|
|
static void
|
|
function_trace_call(unsigned long ip, unsigned long parent_ip)
|
|
{
|
|
struct trace_array *tr = &global_trace;
|
|
struct trace_array_cpu *data;
|
|
unsigned long flags;
|
|
long disabled;
|
|
int cpu;
|
|
int pc;
|
|
|
|
if (unlikely(!ftrace_function_enabled))
|
|
return;
|
|
|
|
/*
|
|
* Need to use raw, since this must be called before the
|
|
* recursive protection is performed.
|
|
*/
|
|
local_irq_save(flags);
|
|
cpu = raw_smp_processor_id();
|
|
data = tr->data[cpu];
|
|
disabled = atomic_inc_return(&data->disabled);
|
|
|
|
if (likely(disabled == 1)) {
|
|
pc = preempt_count();
|
|
trace_function(tr, data, ip, parent_ip, flags, pc);
|
|
}
|
|
|
|
atomic_dec(&data->disabled);
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
int trace_graph_entry(struct ftrace_graph_ent *trace)
|
|
{
|
|
struct trace_array *tr = &global_trace;
|
|
struct trace_array_cpu *data;
|
|
unsigned long flags;
|
|
long disabled;
|
|
int cpu;
|
|
int pc;
|
|
|
|
if (!ftrace_trace_task(current))
|
|
return 0;
|
|
|
|
if (!ftrace_graph_addr(trace->func))
|
|
return 0;
|
|
|
|
local_irq_save(flags);
|
|
cpu = raw_smp_processor_id();
|
|
data = tr->data[cpu];
|
|
disabled = atomic_inc_return(&data->disabled);
|
|
if (likely(disabled == 1)) {
|
|
pc = preempt_count();
|
|
__trace_graph_entry(tr, data, trace, flags, pc);
|
|
}
|
|
/* Only do the atomic if it is not already set */
|
|
if (!test_tsk_trace_graph(current))
|
|
set_tsk_trace_graph(current);
|
|
atomic_dec(&data->disabled);
|
|
local_irq_restore(flags);
|
|
|
|
return 1;
|
|
}
|
|
|
|
void trace_graph_return(struct ftrace_graph_ret *trace)
|
|
{
|
|
struct trace_array *tr = &global_trace;
|
|
struct trace_array_cpu *data;
|
|
unsigned long flags;
|
|
long disabled;
|
|
int cpu;
|
|
int pc;
|
|
|
|
local_irq_save(flags);
|
|
cpu = raw_smp_processor_id();
|
|
data = tr->data[cpu];
|
|
disabled = atomic_inc_return(&data->disabled);
|
|
if (likely(disabled == 1)) {
|
|
pc = preempt_count();
|
|
__trace_graph_return(tr, data, trace, flags, pc);
|
|
}
|
|
if (!trace->depth)
|
|
clear_tsk_trace_graph(current);
|
|
atomic_dec(&data->disabled);
|
|
local_irq_restore(flags);
|
|
}
|
|
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
|
|
|
|
static struct ftrace_ops trace_ops __read_mostly =
|
|
{
|
|
.func = function_trace_call,
|
|
};
|
|
|
|
void tracing_start_function_trace(void)
|
|
{
|
|
ftrace_function_enabled = 0;
|
|
|
|
if (trace_flags & TRACE_ITER_PREEMPTONLY)
|
|
trace_ops.func = function_trace_call_preempt_only;
|
|
else
|
|
trace_ops.func = function_trace_call;
|
|
|
|
register_ftrace_function(&trace_ops);
|
|
ftrace_function_enabled = 1;
|
|
}
|
|
|
|
void tracing_stop_function_trace(void)
|
|
{
|
|
ftrace_function_enabled = 0;
|
|
unregister_ftrace_function(&trace_ops);
|
|
}
|
|
#endif
|
|
|
|
enum trace_file_type {
|
|
TRACE_FILE_LAT_FMT = 1,
|
|
TRACE_FILE_ANNOTATE = 2,
|
|
};
|
|
|
|
static void trace_iterator_increment(struct trace_iterator *iter, int cpu)
|
|
{
|
|
/* Don't allow ftrace to trace into the ring buffers */
|
|
ftrace_disable_cpu();
|
|
|
|
iter->idx++;
|
|
if (iter->buffer_iter[iter->cpu])
|
|
ring_buffer_read(iter->buffer_iter[iter->cpu], NULL);
|
|
|
|
ftrace_enable_cpu();
|
|
}
|
|
|
|
static struct trace_entry *
|
|
peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts)
|
|
{
|
|
struct ring_buffer_event *event;
|
|
struct ring_buffer_iter *buf_iter = iter->buffer_iter[cpu];
|
|
|
|
/* Don't allow ftrace to trace into the ring buffers */
|
|
ftrace_disable_cpu();
|
|
|
|
if (buf_iter)
|
|
event = ring_buffer_iter_peek(buf_iter, ts);
|
|
else
|
|
event = ring_buffer_peek(iter->tr->buffer, cpu, ts);
|
|
|
|
ftrace_enable_cpu();
|
|
|
|
return event ? ring_buffer_event_data(event) : NULL;
|
|
}
|
|
|
|
static struct trace_entry *
|
|
__find_next_entry(struct trace_iterator *iter, int *ent_cpu, u64 *ent_ts)
|
|
{
|
|
struct ring_buffer *buffer = iter->tr->buffer;
|
|
struct trace_entry *ent, *next = NULL;
|
|
u64 next_ts = 0, ts;
|
|
int next_cpu = -1;
|
|
int cpu;
|
|
|
|
for_each_tracing_cpu(cpu) {
|
|
|
|
if (ring_buffer_empty_cpu(buffer, cpu))
|
|
continue;
|
|
|
|
ent = peek_next_entry(iter, cpu, &ts);
|
|
|
|
/*
|
|
* Pick the entry with the smallest timestamp:
|
|
*/
|
|
if (ent && (!next || ts < next_ts)) {
|
|
next = ent;
|
|
next_cpu = cpu;
|
|
next_ts = ts;
|
|
}
|
|
}
|
|
|
|
if (ent_cpu)
|
|
*ent_cpu = next_cpu;
|
|
|
|
if (ent_ts)
|
|
*ent_ts = next_ts;
|
|
|
|
return next;
|
|
}
|
|
|
|
/* Find the next real entry, without updating the iterator itself */
|
|
static struct trace_entry *
|
|
find_next_entry(struct trace_iterator *iter, int *ent_cpu, u64 *ent_ts)
|
|
{
|
|
return __find_next_entry(iter, ent_cpu, ent_ts);
|
|
}
|
|
|
|
/* Find the next real entry, and increment the iterator to the next entry */
|
|
static void *find_next_entry_inc(struct trace_iterator *iter)
|
|
{
|
|
iter->ent = __find_next_entry(iter, &iter->cpu, &iter->ts);
|
|
|
|
if (iter->ent)
|
|
trace_iterator_increment(iter, iter->cpu);
|
|
|
|
return iter->ent ? iter : NULL;
|
|
}
|
|
|
|
static void trace_consume(struct trace_iterator *iter)
|
|
{
|
|
/* Don't allow ftrace to trace into the ring buffers */
|
|
ftrace_disable_cpu();
|
|
ring_buffer_consume(iter->tr->buffer, iter->cpu, &iter->ts);
|
|
ftrace_enable_cpu();
|
|
}
|
|
|
|
static void *s_next(struct seq_file *m, void *v, loff_t *pos)
|
|
{
|
|
struct trace_iterator *iter = m->private;
|
|
int i = (int)*pos;
|
|
void *ent;
|
|
|
|
(*pos)++;
|
|
|
|
/* can't go backwards */
|
|
if (iter->idx > i)
|
|
return NULL;
|
|
|
|
if (iter->idx < 0)
|
|
ent = find_next_entry_inc(iter);
|
|
else
|
|
ent = iter;
|
|
|
|
while (ent && iter->idx < i)
|
|
ent = find_next_entry_inc(iter);
|
|
|
|
iter->pos = *pos;
|
|
|
|
return ent;
|
|
}
|
|
|
|
static void *s_start(struct seq_file *m, loff_t *pos)
|
|
{
|
|
struct trace_iterator *iter = m->private;
|
|
void *p = NULL;
|
|
loff_t l = 0;
|
|
int cpu;
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
|
|
if (!current_trace || current_trace != iter->trace) {
|
|
mutex_unlock(&trace_types_lock);
|
|
return NULL;
|
|
}
|
|
|
|
atomic_inc(&trace_record_cmdline_disabled);
|
|
|
|
if (*pos != iter->pos) {
|
|
iter->ent = NULL;
|
|
iter->cpu = 0;
|
|
iter->idx = -1;
|
|
|
|
ftrace_disable_cpu();
|
|
|
|
for_each_tracing_cpu(cpu) {
|
|
ring_buffer_iter_reset(iter->buffer_iter[cpu]);
|
|
}
|
|
|
|
ftrace_enable_cpu();
|
|
|
|
for (p = iter; p && l < *pos; p = s_next(m, p, &l))
|
|
;
|
|
|
|
} else {
|
|
l = *pos - 1;
|
|
p = s_next(m, p, &l);
|
|
}
|
|
|
|
return p;
|
|
}
|
|
|
|
static void s_stop(struct seq_file *m, void *p)
|
|
{
|
|
atomic_dec(&trace_record_cmdline_disabled);
|
|
mutex_unlock(&trace_types_lock);
|
|
}
|
|
|
|
#ifdef CONFIG_KRETPROBES
|
|
static inline const char *kretprobed(const char *name)
|
|
{
|
|
static const char tramp_name[] = "kretprobe_trampoline";
|
|
int size = sizeof(tramp_name);
|
|
|
|
if (strncmp(tramp_name, name, size) == 0)
|
|
return "[unknown/kretprobe'd]";
|
|
return name;
|
|
}
|
|
#else
|
|
static inline const char *kretprobed(const char *name)
|
|
{
|
|
return name;
|
|
}
|
|
#endif /* CONFIG_KRETPROBES */
|
|
|
|
static int
|
|
seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
|
|
{
|
|
#ifdef CONFIG_KALLSYMS
|
|
char str[KSYM_SYMBOL_LEN];
|
|
const char *name;
|
|
|
|
kallsyms_lookup(address, NULL, NULL, NULL, str);
|
|
|
|
name = kretprobed(str);
|
|
|
|
return trace_seq_printf(s, fmt, name);
|
|
#endif
|
|
return 1;
|
|
}
|
|
|
|
static int
|
|
seq_print_sym_offset(struct trace_seq *s, const char *fmt,
|
|
unsigned long address)
|
|
{
|
|
#ifdef CONFIG_KALLSYMS
|
|
char str[KSYM_SYMBOL_LEN];
|
|
const char *name;
|
|
|
|
sprint_symbol(str, address);
|
|
name = kretprobed(str);
|
|
|
|
return trace_seq_printf(s, fmt, name);
|
|
#endif
|
|
return 1;
|
|
}
|
|
|
|
#ifndef CONFIG_64BIT
|
|
# define IP_FMT "%08lx"
|
|
#else
|
|
# define IP_FMT "%016lx"
|
|
#endif
|
|
|
|
int
|
|
seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
|
|
{
|
|
int ret;
|
|
|
|
if (!ip)
|
|
return trace_seq_printf(s, "0");
|
|
|
|
if (sym_flags & TRACE_ITER_SYM_OFFSET)
|
|
ret = seq_print_sym_offset(s, "%s", ip);
|
|
else
|
|
ret = seq_print_sym_short(s, "%s", ip);
|
|
|
|
if (!ret)
|
|
return 0;
|
|
|
|
if (sym_flags & TRACE_ITER_SYM_ADDR)
|
|
ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
|
|
return ret;
|
|
}
|
|
|
|
static inline int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
|
|
unsigned long ip, unsigned long sym_flags)
|
|
{
|
|
struct file *file = NULL;
|
|
unsigned long vmstart = 0;
|
|
int ret = 1;
|
|
|
|
if (mm) {
|
|
const struct vm_area_struct *vma;
|
|
|
|
down_read(&mm->mmap_sem);
|
|
vma = find_vma(mm, ip);
|
|
if (vma) {
|
|
file = vma->vm_file;
|
|
vmstart = vma->vm_start;
|
|
}
|
|
if (file) {
|
|
ret = trace_seq_path(s, &file->f_path);
|
|
if (ret)
|
|
ret = trace_seq_printf(s, "[+0x%lx]", ip - vmstart);
|
|
}
|
|
up_read(&mm->mmap_sem);
|
|
}
|
|
if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
|
|
ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
|
|
return ret;
|
|
}
|
|
|
|
static int
|
|
seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s,
|
|
unsigned long sym_flags)
|
|
{
|
|
struct mm_struct *mm = NULL;
|
|
int ret = 1;
|
|
unsigned int i;
|
|
|
|
if (trace_flags & TRACE_ITER_SYM_USEROBJ) {
|
|
struct task_struct *task;
|
|
/*
|
|
* we do the lookup on the thread group leader,
|
|
* since individual threads might have already quit!
|
|
*/
|
|
rcu_read_lock();
|
|
task = find_task_by_vpid(entry->ent.tgid);
|
|
if (task)
|
|
mm = get_task_mm(task);
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
|
|
unsigned long ip = entry->caller[i];
|
|
|
|
if (ip == ULONG_MAX || !ret)
|
|
break;
|
|
if (i && ret)
|
|
ret = trace_seq_puts(s, " <- ");
|
|
if (!ip) {
|
|
if (ret)
|
|
ret = trace_seq_puts(s, "??");
|
|
continue;
|
|
}
|
|
if (!ret)
|
|
break;
|
|
if (ret)
|
|
ret = seq_print_user_ip(s, mm, ip, sym_flags);
|
|
}
|
|
|
|
if (mm)
|
|
mmput(mm);
|
|
return ret;
|
|
}
|
|
|
|
static void print_lat_help_header(struct seq_file *m)
|
|
{
|
|
seq_puts(m, "# _------=> CPU# \n");
|
|
seq_puts(m, "# / _-----=> irqs-off \n");
|
|
seq_puts(m, "# | / _----=> need-resched \n");
|
|
seq_puts(m, "# || / _---=> hardirq/softirq \n");
|
|
seq_puts(m, "# ||| / _--=> preempt-depth \n");
|
|
seq_puts(m, "# |||| / \n");
|
|
seq_puts(m, "# ||||| delay \n");
|
|
seq_puts(m, "# cmd pid ||||| time | caller \n");
|
|
seq_puts(m, "# \\ / ||||| \\ | / \n");
|
|
}
|
|
|
|
static void print_func_help_header(struct seq_file *m)
|
|
{
|
|
seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n");
|
|
seq_puts(m, "# | | | | |\n");
|
|
}
|
|
|
|
|
|
static void
|
|
print_trace_header(struct seq_file *m, struct trace_iterator *iter)
|
|
{
|
|
unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
|
|
struct trace_array *tr = iter->tr;
|
|
struct trace_array_cpu *data = tr->data[tr->cpu];
|
|
struct tracer *type = current_trace;
|
|
unsigned long total;
|
|
unsigned long entries;
|
|
const char *name = "preemption";
|
|
|
|
if (type)
|
|
name = type->name;
|
|
|
|
entries = ring_buffer_entries(iter->tr->buffer);
|
|
total = entries +
|
|
ring_buffer_overruns(iter->tr->buffer);
|
|
|
|
seq_printf(m, "%s latency trace v1.1.5 on %s\n",
|
|
name, UTS_RELEASE);
|
|
seq_puts(m, "-----------------------------------"
|
|
"---------------------------------\n");
|
|
seq_printf(m, " latency: %lu us, #%lu/%lu, CPU#%d |"
|
|
" (M:%s VP:%d, KP:%d, SP:%d HP:%d",
|
|
nsecs_to_usecs(data->saved_latency),
|
|
entries,
|
|
total,
|
|
tr->cpu,
|
|
#if defined(CONFIG_PREEMPT_NONE)
|
|
"server",
|
|
#elif defined(CONFIG_PREEMPT_VOLUNTARY)
|
|
"desktop",
|
|
#elif defined(CONFIG_PREEMPT)
|
|
"preempt",
|
|
#else
|
|
"unknown",
|
|
#endif
|
|
/* These are reserved for later use */
|
|
0, 0, 0, 0);
|
|
#ifdef CONFIG_SMP
|
|
seq_printf(m, " #P:%d)\n", num_online_cpus());
|
|
#else
|
|
seq_puts(m, ")\n");
|
|
#endif
|
|
seq_puts(m, " -----------------\n");
|
|
seq_printf(m, " | task: %.16s-%d "
|
|
"(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n",
|
|
data->comm, data->pid, data->uid, data->nice,
|
|
data->policy, data->rt_priority);
|
|
seq_puts(m, " -----------------\n");
|
|
|
|
if (data->critical_start) {
|
|
seq_puts(m, " => started at: ");
|
|
seq_print_ip_sym(&iter->seq, data->critical_start, sym_flags);
|
|
trace_print_seq(m, &iter->seq);
|
|
seq_puts(m, "\n => ended at: ");
|
|
seq_print_ip_sym(&iter->seq, data->critical_end, sym_flags);
|
|
trace_print_seq(m, &iter->seq);
|
|
seq_puts(m, "\n");
|
|
}
|
|
|
|
seq_puts(m, "\n");
|
|
}
|
|
|
|
static void
|
|
lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
|
|
{
|
|
int hardirq, softirq;
|
|
char *comm;
|
|
|
|
comm = trace_find_cmdline(entry->pid);
|
|
|
|
trace_seq_printf(s, "%8.8s-%-5d ", comm, entry->pid);
|
|
trace_seq_printf(s, "%3d", cpu);
|
|
trace_seq_printf(s, "%c%c",
|
|
(entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
|
|
(entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' : '.',
|
|
((entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.'));
|
|
|
|
hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
|
|
softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
|
|
if (hardirq && softirq) {
|
|
trace_seq_putc(s, 'H');
|
|
} else {
|
|
if (hardirq) {
|
|
trace_seq_putc(s, 'h');
|
|
} else {
|
|
if (softirq)
|
|
trace_seq_putc(s, 's');
|
|
else
|
|
trace_seq_putc(s, '.');
|
|
}
|
|
}
|
|
|
|
if (entry->preempt_count)
|
|
trace_seq_printf(s, "%x", entry->preempt_count);
|
|
else
|
|
trace_seq_puts(s, ".");
|
|
}
|
|
|
|
unsigned long preempt_mark_thresh = 100;
|
|
|
|
static void
|
|
lat_print_timestamp(struct trace_seq *s, u64 abs_usecs,
|
|
unsigned long rel_usecs)
|
|
{
|
|
trace_seq_printf(s, " %4lldus", abs_usecs);
|
|
if (rel_usecs > preempt_mark_thresh)
|
|
trace_seq_puts(s, "!: ");
|
|
else if (rel_usecs > 1)
|
|
trace_seq_puts(s, "+: ");
|
|
else
|
|
trace_seq_puts(s, " : ");
|
|
}
|
|
|
|
static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
|
|
|
|
static int task_state_char(unsigned long state)
|
|
{
|
|
int bit = state ? __ffs(state) + 1 : 0;
|
|
|
|
return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
|
|
}
|
|
|
|
static void test_cpu_buff_start(struct trace_iterator *iter)
|
|
{
|
|
struct trace_seq *s = &iter->seq;
|
|
|
|
if (!(trace_flags & TRACE_ITER_ANNOTATE))
|
|
return;
|
|
|
|
if (!(iter->iter_flags & TRACE_FILE_ANNOTATE))
|
|
return;
|
|
|
|
if (cpu_isset(iter->cpu, iter->started))
|
|
return;
|
|
|
|
cpu_set(iter->cpu, iter->started);
|
|
trace_seq_printf(s, "##### CPU %u buffer started ####\n", iter->cpu);
|
|
}
|
|
|
|
static enum print_line_t
|
|
print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
|
|
{
|
|
struct trace_seq *s = &iter->seq;
|
|
unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
|
|
struct trace_entry *next_entry;
|
|
unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE);
|
|
struct trace_entry *entry = iter->ent;
|
|
unsigned long abs_usecs;
|
|
unsigned long rel_usecs;
|
|
u64 next_ts;
|
|
char *comm;
|
|
int S, T;
|
|
int i;
|
|
|
|
test_cpu_buff_start(iter);
|
|
|
|
next_entry = find_next_entry(iter, NULL, &next_ts);
|
|
if (!next_entry)
|
|
next_ts = iter->ts;
|
|
rel_usecs = ns2usecs(next_ts - iter->ts);
|
|
abs_usecs = ns2usecs(iter->ts - iter->tr->time_start);
|
|
|
|
if (verbose) {
|
|
comm = trace_find_cmdline(entry->pid);
|
|
trace_seq_printf(s, "%16s %5d %3d %d %08x %08x [%08lx]"
|
|
" %ld.%03ldms (+%ld.%03ldms): ",
|
|
comm,
|
|
entry->pid, cpu, entry->flags,
|
|
entry->preempt_count, trace_idx,
|
|
ns2usecs(iter->ts),
|
|
abs_usecs/1000,
|
|
abs_usecs % 1000, rel_usecs/1000,
|
|
rel_usecs % 1000);
|
|
} else {
|
|
lat_print_generic(s, entry, cpu);
|
|
lat_print_timestamp(s, abs_usecs, rel_usecs);
|
|
}
|
|
switch (entry->type) {
|
|
case TRACE_FN: {
|
|
struct ftrace_entry *field;
|
|
|
|
trace_assign_type(field, entry);
|
|
|
|
seq_print_ip_sym(s, field->ip, sym_flags);
|
|
trace_seq_puts(s, " (");
|
|
seq_print_ip_sym(s, field->parent_ip, sym_flags);
|
|
trace_seq_puts(s, ")\n");
|
|
break;
|
|
}
|
|
case TRACE_CTX:
|
|
case TRACE_WAKE: {
|
|
struct ctx_switch_entry *field;
|
|
|
|
trace_assign_type(field, entry);
|
|
|
|
T = task_state_char(field->next_state);
|
|
S = task_state_char(field->prev_state);
|
|
comm = trace_find_cmdline(field->next_pid);
|
|
trace_seq_printf(s, " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
|
|
field->prev_pid,
|
|
field->prev_prio,
|
|
S, entry->type == TRACE_CTX ? "==>" : " +",
|
|
field->next_cpu,
|
|
field->next_pid,
|
|
field->next_prio,
|
|
T, comm);
|
|
break;
|
|
}
|
|
case TRACE_SPECIAL: {
|
|
struct special_entry *field;
|
|
|
|
trace_assign_type(field, entry);
|
|
|
|
trace_seq_printf(s, "# %ld %ld %ld\n",
|
|
field->arg1,
|
|
field->arg2,
|
|
field->arg3);
|
|
break;
|
|
}
|
|
case TRACE_STACK: {
|
|
struct stack_entry *field;
|
|
|
|
trace_assign_type(field, entry);
|
|
|
|
for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
|
|
if (i)
|
|
trace_seq_puts(s, " <= ");
|
|
seq_print_ip_sym(s, field->caller[i], sym_flags);
|
|
}
|
|
trace_seq_puts(s, "\n");
|
|
break;
|
|
}
|
|
case TRACE_PRINT: {
|
|
struct print_entry *field;
|
|
|
|
trace_assign_type(field, entry);
|
|
|
|
seq_print_ip_sym(s, field->ip, sym_flags);
|
|
trace_seq_printf(s, ": %s", field->buf);
|
|
break;
|
|
}
|
|
case TRACE_BRANCH: {
|
|
struct trace_branch *field;
|
|
|
|
trace_assign_type(field, entry);
|
|
|
|
trace_seq_printf(s, "[%s] %s:%s:%d\n",
|
|
field->correct ? " ok " : " MISS ",
|
|
field->func,
|
|
field->file,
|
|
field->line);
|
|
break;
|
|
}
|
|
case TRACE_USER_STACK: {
|
|
struct userstack_entry *field;
|
|
|
|
trace_assign_type(field, entry);
|
|
|
|
seq_print_userip_objs(field, s, sym_flags);
|
|
trace_seq_putc(s, '\n');
|
|
break;
|
|
}
|
|
default:
|
|
trace_seq_printf(s, "Unknown type %d\n", entry->type);
|
|
}
|
|
return TRACE_TYPE_HANDLED;
|
|
}
|
|
|
|
static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
|
|
{
|
|
struct trace_seq *s = &iter->seq;
|
|
unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
|
|
struct trace_entry *entry;
|
|
unsigned long usec_rem;
|
|
unsigned long long t;
|
|
unsigned long secs;
|
|
char *comm;
|
|
int ret;
|
|
int S, T;
|
|
int i;
|
|
|
|
entry = iter->ent;
|
|
|
|
test_cpu_buff_start(iter);
|
|
|
|
comm = trace_find_cmdline(iter->ent->pid);
|
|
|
|
t = ns2usecs(iter->ts);
|
|
usec_rem = do_div(t, 1000000ULL);
|
|
secs = (unsigned long)t;
|
|
|
|
ret = trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid);
|
|
if (!ret)
|
|
return TRACE_TYPE_PARTIAL_LINE;
|
|
ret = trace_seq_printf(s, "[%03d] ", iter->cpu);
|
|
if (!ret)
|
|
return TRACE_TYPE_PARTIAL_LINE;
|
|
ret = trace_seq_printf(s, "%5lu.%06lu: ", secs, usec_rem);
|
|
if (!ret)
|
|
return TRACE_TYPE_PARTIAL_LINE;
|
|
|
|
switch (entry->type) {
|
|
case TRACE_FN: {
|
|
struct ftrace_entry *field;
|
|
|
|
trace_assign_type(field, entry);
|
|
|
|
ret = seq_print_ip_sym(s, field->ip, sym_flags);
|
|
if (!ret)
|
|
return TRACE_TYPE_PARTIAL_LINE;
|
|
if ((sym_flags & TRACE_ITER_PRINT_PARENT) &&
|
|
field->parent_ip) {
|
|
ret = trace_seq_printf(s, " <-");
|
|
if (!ret)
|
|
return TRACE_TYPE_PARTIAL_LINE;
|
|
ret = seq_print_ip_sym(s,
|
|
field->parent_ip,
|
|
sym_flags);
|
|
if (!ret)
|
|
return TRACE_TYPE_PARTIAL_LINE;
|
|
}
|
|
ret = trace_seq_printf(s, "\n");
|
|
if (!ret)
|
|
return TRACE_TYPE_PARTIAL_LINE;
|
|
break;
|
|
}
|
|
case TRACE_CTX:
|
|
case TRACE_WAKE: {
|
|
struct ctx_switch_entry *field;
|
|
|
|
trace_assign_type(field, entry);
|
|
|
|
T = task_state_char(field->next_state);
|
|
S = task_state_char(field->prev_state);
|
|
ret = trace_seq_printf(s, " %5d:%3d:%c %s [%03d] %5d:%3d:%c\n",
|
|
field->prev_pid,
|
|
field->prev_prio,
|
|
S,
|
|
entry->type == TRACE_CTX ? "==>" : " +",
|
|
field->next_cpu,
|
|
field->next_pid,
|
|
field->next_prio,
|
|
T);
|
|
if (!ret)
|
|
return TRACE_TYPE_PARTIAL_LINE;
|
|
break;
|
|
}
|
|
case TRACE_SPECIAL: {
|
|
struct special_entry *field;
|
|
|
|
trace_assign_type(field, entry);
|
|
|
|
ret = trace_seq_printf(s, "# %ld %ld %ld\n",
|
|
field->arg1,
|
|
field->arg2,
|
|
field->arg3);
|
|
if (!ret)
|
|
return TRACE_TYPE_PARTIAL_LINE;
|
|
break;
|
|
}
|
|
case TRACE_STACK: {
|
|
struct stack_entry *field;
|
|
|
|
trace_assign_type(field, entry);
|
|
|
|
for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
|
|
if (i) {
|
|
ret = trace_seq_puts(s, " <= ");
|
|
if (!ret)
|
|
return TRACE_TYPE_PARTIAL_LINE;
|
|
}
|
|
ret = seq_print_ip_sym(s, field->caller[i],
|
|
sym_flags);
|
|
if (!ret)
|
|
return TRACE_TYPE_PARTIAL_LINE;
|
|
}
|
|
ret = trace_seq_puts(s, "\n");
|
|
if (!ret)
|
|
return TRACE_TYPE_PARTIAL_LINE;
|
|
break;
|
|
}
|
|
case TRACE_PRINT: {
|
|
struct print_entry *field;
|
|
|
|
trace_assign_type(field, entry);
|
|
|
|
seq_print_ip_sym(s, field->ip, sym_flags);
|
|
trace_seq_printf(s, ": %s", field->buf);
|
|
break;
|
|
}
|
|
case TRACE_GRAPH_RET: {
|
|
return print_graph_function(iter);
|
|
}
|
|
case TRACE_GRAPH_ENT: {
|
|
return print_graph_function(iter);
|
|
}
|
|
case TRACE_BRANCH: {
|
|
struct trace_branch *field;
|
|
|
|
trace_assign_type(field, entry);
|
|
|
|
trace_seq_printf(s, "[%s] %s:%s:%d\n",
|
|
field->correct ? " ok " : " MISS ",
|
|
field->func,
|
|
field->file,
|
|
field->line);
|
|
break;
|
|
}
|
|
case TRACE_USER_STACK: {
|
|
struct userstack_entry *field;
|
|
|
|
trace_assign_type(field, entry);
|
|
|
|
ret = seq_print_userip_objs(field, s, sym_flags);
|
|
if (!ret)
|
|
return TRACE_TYPE_PARTIAL_LINE;
|
|
ret = trace_seq_putc(s, '\n');
|
|
if (!ret)
|
|
return TRACE_TYPE_PARTIAL_LINE;
|
|
break;
|
|
}
|
|
}
|
|
return TRACE_TYPE_HANDLED;
|
|
}
|
|
|
|
static enum print_line_t print_raw_fmt(struct trace_iterator *iter)
|
|
{
|
|
struct trace_seq *s = &iter->seq;
|
|
struct trace_entry *entry;
|
|
int ret;
|
|
int S, T;
|
|
|
|
entry = iter->ent;
|
|
|
|
ret = trace_seq_printf(s, "%d %d %llu ",
|
|
entry->pid, iter->cpu, iter->ts);
|
|
if (!ret)
|
|
return TRACE_TYPE_PARTIAL_LINE;
|
|
|
|
switch (entry->type) {
|
|
case TRACE_FN: {
|
|
struct ftrace_entry *field;
|
|
|
|
trace_assign_type(field, entry);
|
|
|
|
ret = trace_seq_printf(s, "%x %x\n",
|
|
field->ip,
|
|
field->parent_ip);
|
|
if (!ret)
|
|
return TRACE_TYPE_PARTIAL_LINE;
|
|
break;
|
|
}
|
|
case TRACE_CTX:
|
|
case TRACE_WAKE: {
|
|
struct ctx_switch_entry *field;
|
|
|
|
trace_assign_type(field, entry);
|
|
|
|
T = task_state_char(field->next_state);
|
|
S = entry->type == TRACE_WAKE ? '+' :
|
|
task_state_char(field->prev_state);
|
|
ret = trace_seq_printf(s, "%d %d %c %d %d %d %c\n",
|
|
field->prev_pid,
|
|
field->prev_prio,
|
|
S,
|
|
field->next_cpu,
|
|
field->next_pid,
|
|
field->next_prio,
|
|
T);
|
|
if (!ret)
|
|
return TRACE_TYPE_PARTIAL_LINE;
|
|
break;
|
|
}
|
|
case TRACE_SPECIAL:
|
|
case TRACE_USER_STACK:
|
|
case TRACE_STACK: {
|
|
struct special_entry *field;
|
|
|
|
trace_assign_type(field, entry);
|
|
|
|
ret = trace_seq_printf(s, "# %ld %ld %ld\n",
|
|
field->arg1,
|
|
field->arg2,
|
|
field->arg3);
|
|
if (!ret)
|
|
return TRACE_TYPE_PARTIAL_LINE;
|
|
break;
|
|
}
|
|
case TRACE_PRINT: {
|
|
struct print_entry *field;
|
|
|
|
trace_assign_type(field, entry);
|
|
|
|
trace_seq_printf(s, "# %lx %s", field->ip, field->buf);
|
|
break;
|
|
}
|
|
}
|
|
return TRACE_TYPE_HANDLED;
|
|
}
|
|
|
|
#define SEQ_PUT_FIELD_RET(s, x) \
|
|
do { \
|
|
if (!trace_seq_putmem(s, &(x), sizeof(x))) \
|
|
return 0; \
|
|
} while (0)
|
|
|
|
#define SEQ_PUT_HEX_FIELD_RET(s, x) \
|
|
do { \
|
|
BUILD_BUG_ON(sizeof(x) > MAX_MEMHEX_BYTES); \
|
|
if (!trace_seq_putmem_hex(s, &(x), sizeof(x))) \
|
|
return 0; \
|
|
} while (0)
|
|
|
|
static enum print_line_t print_hex_fmt(struct trace_iterator *iter)
|
|
{
|
|
struct trace_seq *s = &iter->seq;
|
|
unsigned char newline = '\n';
|
|
struct trace_entry *entry;
|
|
int S, T;
|
|
|
|
entry = iter->ent;
|
|
|
|
SEQ_PUT_HEX_FIELD_RET(s, entry->pid);
|
|
SEQ_PUT_HEX_FIELD_RET(s, iter->cpu);
|
|
SEQ_PUT_HEX_FIELD_RET(s, iter->ts);
|
|
|
|
switch (entry->type) {
|
|
case TRACE_FN: {
|
|
struct ftrace_entry *field;
|
|
|
|
trace_assign_type(field, entry);
|
|
|
|
SEQ_PUT_HEX_FIELD_RET(s, field->ip);
|
|
SEQ_PUT_HEX_FIELD_RET(s, field->parent_ip);
|
|
break;
|
|
}
|
|
case TRACE_CTX:
|
|
case TRACE_WAKE: {
|
|
struct ctx_switch_entry *field;
|
|
|
|
trace_assign_type(field, entry);
|
|
|
|
T = task_state_char(field->next_state);
|
|
S = entry->type == TRACE_WAKE ? '+' :
|
|
task_state_char(field->prev_state);
|
|
SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid);
|
|
SEQ_PUT_HEX_FIELD_RET(s, field->prev_prio);
|
|
SEQ_PUT_HEX_FIELD_RET(s, S);
|
|
SEQ_PUT_HEX_FIELD_RET(s, field->next_cpu);
|
|
SEQ_PUT_HEX_FIELD_RET(s, field->next_pid);
|
|
SEQ_PUT_HEX_FIELD_RET(s, field->next_prio);
|
|
SEQ_PUT_HEX_FIELD_RET(s, T);
|
|
break;
|
|
}
|
|
case TRACE_SPECIAL:
|
|
case TRACE_USER_STACK:
|
|
case TRACE_STACK: {
|
|
struct special_entry *field;
|
|
|
|
trace_assign_type(field, entry);
|
|
|
|
SEQ_PUT_HEX_FIELD_RET(s, field->arg1);
|
|
SEQ_PUT_HEX_FIELD_RET(s, field->arg2);
|
|
SEQ_PUT_HEX_FIELD_RET(s, field->arg3);
|
|
break;
|
|
}
|
|
}
|
|
SEQ_PUT_FIELD_RET(s, newline);
|
|
|
|
return TRACE_TYPE_HANDLED;
|
|
}
|
|
|
|
static enum print_line_t print_printk_msg_only(struct trace_iterator *iter)
|
|
{
|
|
struct trace_seq *s = &iter->seq;
|
|
struct trace_entry *entry = iter->ent;
|
|
struct print_entry *field;
|
|
int ret;
|
|
|
|
trace_assign_type(field, entry);
|
|
|
|
ret = trace_seq_printf(s, field->buf);
|
|
if (!ret)
|
|
return TRACE_TYPE_PARTIAL_LINE;
|
|
|
|
return TRACE_TYPE_HANDLED;
|
|
}
|
|
|
|
static enum print_line_t print_bin_fmt(struct trace_iterator *iter)
|
|
{
|
|
struct trace_seq *s = &iter->seq;
|
|
struct trace_entry *entry;
|
|
|
|
entry = iter->ent;
|
|
|
|
SEQ_PUT_FIELD_RET(s, entry->pid);
|
|
SEQ_PUT_FIELD_RET(s, entry->cpu);
|
|
SEQ_PUT_FIELD_RET(s, iter->ts);
|
|
|
|
switch (entry->type) {
|
|
case TRACE_FN: {
|
|
struct ftrace_entry *field;
|
|
|
|
trace_assign_type(field, entry);
|
|
|
|
SEQ_PUT_FIELD_RET(s, field->ip);
|
|
SEQ_PUT_FIELD_RET(s, field->parent_ip);
|
|
break;
|
|
}
|
|
case TRACE_CTX: {
|
|
struct ctx_switch_entry *field;
|
|
|
|
trace_assign_type(field, entry);
|
|
|
|
SEQ_PUT_FIELD_RET(s, field->prev_pid);
|
|
SEQ_PUT_FIELD_RET(s, field->prev_prio);
|
|
SEQ_PUT_FIELD_RET(s, field->prev_state);
|
|
SEQ_PUT_FIELD_RET(s, field->next_pid);
|
|
SEQ_PUT_FIELD_RET(s, field->next_prio);
|
|
SEQ_PUT_FIELD_RET(s, field->next_state);
|
|
break;
|
|
}
|
|
case TRACE_SPECIAL:
|
|
case TRACE_USER_STACK:
|
|
case TRACE_STACK: {
|
|
struct special_entry *field;
|
|
|
|
trace_assign_type(field, entry);
|
|
|
|
SEQ_PUT_FIELD_RET(s, field->arg1);
|
|
SEQ_PUT_FIELD_RET(s, field->arg2);
|
|
SEQ_PUT_FIELD_RET(s, field->arg3);
|
|
break;
|
|
}
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
static int trace_empty(struct trace_iterator *iter)
|
|
{
|
|
int cpu;
|
|
|
|
for_each_tracing_cpu(cpu) {
|
|
if (iter->buffer_iter[cpu]) {
|
|
if (!ring_buffer_iter_empty(iter->buffer_iter[cpu]))
|
|
return 0;
|
|
} else {
|
|
if (!ring_buffer_empty_cpu(iter->tr->buffer, cpu))
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
static enum print_line_t print_trace_line(struct trace_iterator *iter)
|
|
{
|
|
enum print_line_t ret;
|
|
|
|
if (iter->trace && iter->trace->print_line) {
|
|
ret = iter->trace->print_line(iter);
|
|
if (ret != TRACE_TYPE_UNHANDLED)
|
|
return ret;
|
|
}
|
|
|
|
if (iter->ent->type == TRACE_PRINT &&
|
|
trace_flags & TRACE_ITER_PRINTK &&
|
|
trace_flags & TRACE_ITER_PRINTK_MSGONLY)
|
|
return print_printk_msg_only(iter);
|
|
|
|
if (trace_flags & TRACE_ITER_BIN)
|
|
return print_bin_fmt(iter);
|
|
|
|
if (trace_flags & TRACE_ITER_HEX)
|
|
return print_hex_fmt(iter);
|
|
|
|
if (trace_flags & TRACE_ITER_RAW)
|
|
return print_raw_fmt(iter);
|
|
|
|
if (iter->iter_flags & TRACE_FILE_LAT_FMT)
|
|
return print_lat_fmt(iter, iter->idx, iter->cpu);
|
|
|
|
return print_trace_fmt(iter);
|
|
}
|
|
|
|
static int s_show(struct seq_file *m, void *v)
|
|
{
|
|
struct trace_iterator *iter = v;
|
|
|
|
if (iter->ent == NULL) {
|
|
if (iter->tr) {
|
|
seq_printf(m, "# tracer: %s\n", iter->trace->name);
|
|
seq_puts(m, "#\n");
|
|
}
|
|
if (iter->trace && iter->trace->print_header)
|
|
iter->trace->print_header(m);
|
|
else if (iter->iter_flags & TRACE_FILE_LAT_FMT) {
|
|
/* print nothing if the buffers are empty */
|
|
if (trace_empty(iter))
|
|
return 0;
|
|
print_trace_header(m, iter);
|
|
if (!(trace_flags & TRACE_ITER_VERBOSE))
|
|
print_lat_help_header(m);
|
|
} else {
|
|
if (!(trace_flags & TRACE_ITER_VERBOSE))
|
|
print_func_help_header(m);
|
|
}
|
|
} else {
|
|
print_trace_line(iter);
|
|
trace_print_seq(m, &iter->seq);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct seq_operations tracer_seq_ops = {
|
|
.start = s_start,
|
|
.next = s_next,
|
|
.stop = s_stop,
|
|
.show = s_show,
|
|
};
|
|
|
|
static struct trace_iterator *
|
|
__tracing_open(struct inode *inode, struct file *file, int *ret)
|
|
{
|
|
struct trace_iterator *iter;
|
|
struct seq_file *m;
|
|
int cpu;
|
|
|
|
if (tracing_disabled) {
|
|
*ret = -ENODEV;
|
|
return NULL;
|
|
}
|
|
|
|
iter = kzalloc(sizeof(*iter), GFP_KERNEL);
|
|
if (!iter) {
|
|
*ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
if (current_trace && current_trace->print_max)
|
|
iter->tr = &max_tr;
|
|
else
|
|
iter->tr = inode->i_private;
|
|
iter->trace = current_trace;
|
|
iter->pos = -1;
|
|
|
|
/* Notify the tracer early; before we stop tracing. */
|
|
if (iter->trace && iter->trace->open)
|
|
iter->trace->open(iter);
|
|
|
|
/* Annotate start of buffers if we had overruns */
|
|
if (ring_buffer_overruns(iter->tr->buffer))
|
|
iter->iter_flags |= TRACE_FILE_ANNOTATE;
|
|
|
|
|
|
for_each_tracing_cpu(cpu) {
|
|
|
|
iter->buffer_iter[cpu] =
|
|
ring_buffer_read_start(iter->tr->buffer, cpu);
|
|
|
|
if (!iter->buffer_iter[cpu])
|
|
goto fail_buffer;
|
|
}
|
|
|
|
/* TODO stop tracer */
|
|
*ret = seq_open(file, &tracer_seq_ops);
|
|
if (*ret)
|
|
goto fail_buffer;
|
|
|
|
m = file->private_data;
|
|
m->private = iter;
|
|
|
|
/* stop the trace while dumping */
|
|
tracing_stop();
|
|
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
out:
|
|
return iter;
|
|
|
|
fail_buffer:
|
|
for_each_tracing_cpu(cpu) {
|
|
if (iter->buffer_iter[cpu])
|
|
ring_buffer_read_finish(iter->buffer_iter[cpu]);
|
|
}
|
|
mutex_unlock(&trace_types_lock);
|
|
kfree(iter);
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
|
|
int tracing_open_generic(struct inode *inode, struct file *filp)
|
|
{
|
|
if (tracing_disabled)
|
|
return -ENODEV;
|
|
|
|
filp->private_data = inode->i_private;
|
|
return 0;
|
|
}
|
|
|
|
int tracing_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct seq_file *m = (struct seq_file *)file->private_data;
|
|
struct trace_iterator *iter = m->private;
|
|
int cpu;
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
for_each_tracing_cpu(cpu) {
|
|
if (iter->buffer_iter[cpu])
|
|
ring_buffer_read_finish(iter->buffer_iter[cpu]);
|
|
}
|
|
|
|
if (iter->trace && iter->trace->close)
|
|
iter->trace->close(iter);
|
|
|
|
/* reenable tracing if it was previously enabled */
|
|
tracing_start();
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
seq_release(inode, file);
|
|
kfree(iter);
|
|
return 0;
|
|
}
|
|
|
|
static int tracing_open(struct inode *inode, struct file *file)
|
|
{
|
|
int ret;
|
|
|
|
__tracing_open(inode, file, &ret);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int tracing_lt_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct trace_iterator *iter;
|
|
int ret;
|
|
|
|
iter = __tracing_open(inode, file, &ret);
|
|
|
|
if (!ret)
|
|
iter->iter_flags |= TRACE_FILE_LAT_FMT;
|
|
|
|
return ret;
|
|
}
|
|
|
|
|
|
static void *
|
|
t_next(struct seq_file *m, void *v, loff_t *pos)
|
|
{
|
|
struct tracer *t = m->private;
|
|
|
|
(*pos)++;
|
|
|
|
if (t)
|
|
t = t->next;
|
|
|
|
m->private = t;
|
|
|
|
return t;
|
|
}
|
|
|
|
static void *t_start(struct seq_file *m, loff_t *pos)
|
|
{
|
|
struct tracer *t = m->private;
|
|
loff_t l = 0;
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
for (; t && l < *pos; t = t_next(m, t, &l))
|
|
;
|
|
|
|
return t;
|
|
}
|
|
|
|
static void t_stop(struct seq_file *m, void *p)
|
|
{
|
|
mutex_unlock(&trace_types_lock);
|
|
}
|
|
|
|
static int t_show(struct seq_file *m, void *v)
|
|
{
|
|
struct tracer *t = v;
|
|
|
|
if (!t)
|
|
return 0;
|
|
|
|
seq_printf(m, "%s", t->name);
|
|
if (t->next)
|
|
seq_putc(m, ' ');
|
|
else
|
|
seq_putc(m, '\n');
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct seq_operations show_traces_seq_ops = {
|
|
.start = t_start,
|
|
.next = t_next,
|
|
.stop = t_stop,
|
|
.show = t_show,
|
|
};
|
|
|
|
static int show_traces_open(struct inode *inode, struct file *file)
|
|
{
|
|
int ret;
|
|
|
|
if (tracing_disabled)
|
|
return -ENODEV;
|
|
|
|
ret = seq_open(file, &show_traces_seq_ops);
|
|
if (!ret) {
|
|
struct seq_file *m = file->private_data;
|
|
m->private = trace_types;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static struct file_operations tracing_fops = {
|
|
.open = tracing_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = tracing_release,
|
|
};
|
|
|
|
static struct file_operations tracing_lt_fops = {
|
|
.open = tracing_lt_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = tracing_release,
|
|
};
|
|
|
|
static struct file_operations show_traces_fops = {
|
|
.open = show_traces_open,
|
|
.read = seq_read,
|
|
.release = seq_release,
|
|
};
|
|
|
|
/*
|
|
* Only trace on a CPU if the bitmask is set:
|
|
*/
|
|
static cpumask_t tracing_cpumask = CPU_MASK_ALL;
|
|
|
|
/*
|
|
* When tracing/tracing_cpu_mask is modified then this holds
|
|
* the new bitmask we are about to install:
|
|
*/
|
|
static cpumask_t tracing_cpumask_new;
|
|
|
|
/*
|
|
* The tracer itself will not take this lock, but still we want
|
|
* to provide a consistent cpumask to user-space:
|
|
*/
|
|
static DEFINE_MUTEX(tracing_cpumask_update_lock);
|
|
|
|
/*
|
|
* Temporary storage for the character representation of the
|
|
* CPU bitmask (and one more byte for the newline):
|
|
*/
|
|
static char mask_str[NR_CPUS + 1];
|
|
|
|
static ssize_t
|
|
tracing_cpumask_read(struct file *filp, char __user *ubuf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
int len;
|
|
|
|
mutex_lock(&tracing_cpumask_update_lock);
|
|
|
|
len = cpumask_scnprintf(mask_str, count, tracing_cpumask);
|
|
if (count - len < 2) {
|
|
count = -EINVAL;
|
|
goto out_err;
|
|
}
|
|
len += sprintf(mask_str + len, "\n");
|
|
count = simple_read_from_buffer(ubuf, count, ppos, mask_str, NR_CPUS+1);
|
|
|
|
out_err:
|
|
mutex_unlock(&tracing_cpumask_update_lock);
|
|
|
|
return count;
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_cpumask_write(struct file *filp, const char __user *ubuf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
int err, cpu;
|
|
|
|
mutex_lock(&tracing_cpumask_update_lock);
|
|
err = cpumask_parse_user(ubuf, count, tracing_cpumask_new);
|
|
if (err)
|
|
goto err_unlock;
|
|
|
|
local_irq_disable();
|
|
__raw_spin_lock(&ftrace_max_lock);
|
|
for_each_tracing_cpu(cpu) {
|
|
/*
|
|
* Increase/decrease the disabled counter if we are
|
|
* about to flip a bit in the cpumask:
|
|
*/
|
|
if (cpu_isset(cpu, tracing_cpumask) &&
|
|
!cpu_isset(cpu, tracing_cpumask_new)) {
|
|
atomic_inc(&global_trace.data[cpu]->disabled);
|
|
}
|
|
if (!cpu_isset(cpu, tracing_cpumask) &&
|
|
cpu_isset(cpu, tracing_cpumask_new)) {
|
|
atomic_dec(&global_trace.data[cpu]->disabled);
|
|
}
|
|
}
|
|
__raw_spin_unlock(&ftrace_max_lock);
|
|
local_irq_enable();
|
|
|
|
tracing_cpumask = tracing_cpumask_new;
|
|
|
|
mutex_unlock(&tracing_cpumask_update_lock);
|
|
|
|
return count;
|
|
|
|
err_unlock:
|
|
mutex_unlock(&tracing_cpumask_update_lock);
|
|
|
|
return err;
|
|
}
|
|
|
|
static struct file_operations tracing_cpumask_fops = {
|
|
.open = tracing_open_generic,
|
|
.read = tracing_cpumask_read,
|
|
.write = tracing_cpumask_write,
|
|
};
|
|
|
|
static ssize_t
|
|
tracing_trace_options_read(struct file *filp, char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
int i;
|
|
char *buf;
|
|
int r = 0;
|
|
int len = 0;
|
|
u32 tracer_flags = current_trace->flags->val;
|
|
struct tracer_opt *trace_opts = current_trace->flags->opts;
|
|
|
|
|
|
/* calulate max size */
|
|
for (i = 0; trace_options[i]; i++) {
|
|
len += strlen(trace_options[i]);
|
|
len += 3; /* "no" and space */
|
|
}
|
|
|
|
/*
|
|
* Increase the size with names of options specific
|
|
* of the current tracer.
|
|
*/
|
|
for (i = 0; trace_opts[i].name; i++) {
|
|
len += strlen(trace_opts[i].name);
|
|
len += 3; /* "no" and space */
|
|
}
|
|
|
|
/* +2 for \n and \0 */
|
|
buf = kmalloc(len + 2, GFP_KERNEL);
|
|
if (!buf)
|
|
return -ENOMEM;
|
|
|
|
for (i = 0; trace_options[i]; i++) {
|
|
if (trace_flags & (1 << i))
|
|
r += sprintf(buf + r, "%s ", trace_options[i]);
|
|
else
|
|
r += sprintf(buf + r, "no%s ", trace_options[i]);
|
|
}
|
|
|
|
for (i = 0; trace_opts[i].name; i++) {
|
|
if (tracer_flags & trace_opts[i].bit)
|
|
r += sprintf(buf + r, "%s ",
|
|
trace_opts[i].name);
|
|
else
|
|
r += sprintf(buf + r, "no%s ",
|
|
trace_opts[i].name);
|
|
}
|
|
|
|
r += sprintf(buf + r, "\n");
|
|
WARN_ON(r >= len + 2);
|
|
|
|
r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
|
|
|
|
kfree(buf);
|
|
|
|
return r;
|
|
}
|
|
|
|
/* Try to assign a tracer specific option */
|
|
static int set_tracer_option(struct tracer *trace, char *cmp, int neg)
|
|
{
|
|
struct tracer_flags *trace_flags = trace->flags;
|
|
struct tracer_opt *opts = NULL;
|
|
int ret = 0, i = 0;
|
|
int len;
|
|
|
|
for (i = 0; trace_flags->opts[i].name; i++) {
|
|
opts = &trace_flags->opts[i];
|
|
len = strlen(opts->name);
|
|
|
|
if (strncmp(cmp, opts->name, len) == 0) {
|
|
ret = trace->set_flag(trace_flags->val,
|
|
opts->bit, !neg);
|
|
break;
|
|
}
|
|
}
|
|
/* Not found */
|
|
if (!trace_flags->opts[i].name)
|
|
return -EINVAL;
|
|
|
|
/* Refused to handle */
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (neg)
|
|
trace_flags->val &= ~opts->bit;
|
|
else
|
|
trace_flags->val |= opts->bit;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_trace_options_write(struct file *filp, const char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
char buf[64];
|
|
char *cmp = buf;
|
|
int neg = 0;
|
|
int ret;
|
|
int i;
|
|
|
|
if (cnt >= sizeof(buf))
|
|
return -EINVAL;
|
|
|
|
if (copy_from_user(&buf, ubuf, cnt))
|
|
return -EFAULT;
|
|
|
|
buf[cnt] = 0;
|
|
|
|
if (strncmp(buf, "no", 2) == 0) {
|
|
neg = 1;
|
|
cmp += 2;
|
|
}
|
|
|
|
for (i = 0; trace_options[i]; i++) {
|
|
int len = strlen(trace_options[i]);
|
|
|
|
if (strncmp(cmp, trace_options[i], len) == 0) {
|
|
if (neg)
|
|
trace_flags &= ~(1 << i);
|
|
else
|
|
trace_flags |= (1 << i);
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* If no option could be set, test the specific tracer options */
|
|
if (!trace_options[i]) {
|
|
ret = set_tracer_option(current_trace, cmp, neg);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
filp->f_pos += cnt;
|
|
|
|
return cnt;
|
|
}
|
|
|
|
static struct file_operations tracing_iter_fops = {
|
|
.open = tracing_open_generic,
|
|
.read = tracing_trace_options_read,
|
|
.write = tracing_trace_options_write,
|
|
};
|
|
|
|
static const char readme_msg[] =
|
|
"tracing mini-HOWTO:\n\n"
|
|
"# mkdir /debug\n"
|
|
"# mount -t debugfs nodev /debug\n\n"
|
|
"# cat /debug/tracing/available_tracers\n"
|
|
"wakeup preemptirqsoff preemptoff irqsoff ftrace sched_switch none\n\n"
|
|
"# cat /debug/tracing/current_tracer\n"
|
|
"none\n"
|
|
"# echo sched_switch > /debug/tracing/current_tracer\n"
|
|
"# cat /debug/tracing/current_tracer\n"
|
|
"sched_switch\n"
|
|
"# cat /debug/tracing/trace_options\n"
|
|
"noprint-parent nosym-offset nosym-addr noverbose\n"
|
|
"# echo print-parent > /debug/tracing/trace_options\n"
|
|
"# echo 1 > /debug/tracing/tracing_enabled\n"
|
|
"# cat /debug/tracing/trace > /tmp/trace.txt\n"
|
|
"echo 0 > /debug/tracing/tracing_enabled\n"
|
|
;
|
|
|
|
static ssize_t
|
|
tracing_readme_read(struct file *filp, char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
return simple_read_from_buffer(ubuf, cnt, ppos,
|
|
readme_msg, strlen(readme_msg));
|
|
}
|
|
|
|
static struct file_operations tracing_readme_fops = {
|
|
.open = tracing_open_generic,
|
|
.read = tracing_readme_read,
|
|
};
|
|
|
|
static ssize_t
|
|
tracing_ctrl_read(struct file *filp, char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
char buf[64];
|
|
int r;
|
|
|
|
r = sprintf(buf, "%u\n", tracer_enabled);
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_ctrl_write(struct file *filp, const char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
struct trace_array *tr = filp->private_data;
|
|
char buf[64];
|
|
long val;
|
|
int ret;
|
|
|
|
if (cnt >= sizeof(buf))
|
|
return -EINVAL;
|
|
|
|
if (copy_from_user(&buf, ubuf, cnt))
|
|
return -EFAULT;
|
|
|
|
buf[cnt] = 0;
|
|
|
|
ret = strict_strtoul(buf, 10, &val);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
val = !!val;
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
if (tracer_enabled ^ val) {
|
|
if (val) {
|
|
tracer_enabled = 1;
|
|
if (current_trace->start)
|
|
current_trace->start(tr);
|
|
tracing_start();
|
|
} else {
|
|
tracer_enabled = 0;
|
|
tracing_stop();
|
|
if (current_trace->stop)
|
|
current_trace->stop(tr);
|
|
}
|
|
}
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
filp->f_pos += cnt;
|
|
|
|
return cnt;
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_set_trace_read(struct file *filp, char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
char buf[max_tracer_type_len+2];
|
|
int r;
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
if (current_trace)
|
|
r = sprintf(buf, "%s\n", current_trace->name);
|
|
else
|
|
r = sprintf(buf, "\n");
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
|
|
}
|
|
|
|
static int tracing_set_tracer(char *buf)
|
|
{
|
|
struct trace_array *tr = &global_trace;
|
|
struct tracer *t;
|
|
int ret = 0;
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
for (t = trace_types; t; t = t->next) {
|
|
if (strcmp(t->name, buf) == 0)
|
|
break;
|
|
}
|
|
if (!t) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
if (t == current_trace)
|
|
goto out;
|
|
|
|
trace_branch_disable();
|
|
if (current_trace && current_trace->reset)
|
|
current_trace->reset(tr);
|
|
|
|
current_trace = t;
|
|
if (t->init) {
|
|
ret = t->init(tr);
|
|
if (ret)
|
|
goto out;
|
|
}
|
|
|
|
trace_branch_enable(tr);
|
|
out:
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_set_trace_write(struct file *filp, const char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
char buf[max_tracer_type_len+1];
|
|
int i;
|
|
size_t ret;
|
|
int err;
|
|
|
|
ret = cnt;
|
|
|
|
if (cnt > max_tracer_type_len)
|
|
cnt = max_tracer_type_len;
|
|
|
|
if (copy_from_user(&buf, ubuf, cnt))
|
|
return -EFAULT;
|
|
|
|
buf[cnt] = 0;
|
|
|
|
/* strip ending whitespace. */
|
|
for (i = cnt - 1; i > 0 && isspace(buf[i]); i--)
|
|
buf[i] = 0;
|
|
|
|
err = tracing_set_tracer(buf);
|
|
if (err)
|
|
return err;
|
|
|
|
filp->f_pos += ret;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_max_lat_read(struct file *filp, char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
unsigned long *ptr = filp->private_data;
|
|
char buf[64];
|
|
int r;
|
|
|
|
r = snprintf(buf, sizeof(buf), "%ld\n",
|
|
*ptr == (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr));
|
|
if (r > sizeof(buf))
|
|
r = sizeof(buf);
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_max_lat_write(struct file *filp, const char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
long *ptr = filp->private_data;
|
|
char buf[64];
|
|
long val;
|
|
int ret;
|
|
|
|
if (cnt >= sizeof(buf))
|
|
return -EINVAL;
|
|
|
|
if (copy_from_user(&buf, ubuf, cnt))
|
|
return -EFAULT;
|
|
|
|
buf[cnt] = 0;
|
|
|
|
ret = strict_strtoul(buf, 10, &val);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
*ptr = val * 1000;
|
|
|
|
return cnt;
|
|
}
|
|
|
|
static atomic_t tracing_reader;
|
|
|
|
static int tracing_open_pipe(struct inode *inode, struct file *filp)
|
|
{
|
|
struct trace_iterator *iter;
|
|
|
|
if (tracing_disabled)
|
|
return -ENODEV;
|
|
|
|
/* We only allow for reader of the pipe */
|
|
if (atomic_inc_return(&tracing_reader) != 1) {
|
|
atomic_dec(&tracing_reader);
|
|
return -EBUSY;
|
|
}
|
|
|
|
/* create a buffer to store the information to pass to userspace */
|
|
iter = kzalloc(sizeof(*iter), GFP_KERNEL);
|
|
if (!iter)
|
|
return -ENOMEM;
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
|
|
/* trace pipe does not show start of buffer */
|
|
cpus_setall(iter->started);
|
|
|
|
iter->tr = &global_trace;
|
|
iter->trace = current_trace;
|
|
filp->private_data = iter;
|
|
|
|
if (iter->trace->pipe_open)
|
|
iter->trace->pipe_open(iter);
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int tracing_release_pipe(struct inode *inode, struct file *file)
|
|
{
|
|
struct trace_iterator *iter = file->private_data;
|
|
|
|
kfree(iter);
|
|
atomic_dec(&tracing_reader);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static unsigned int
|
|
tracing_poll_pipe(struct file *filp, poll_table *poll_table)
|
|
{
|
|
struct trace_iterator *iter = filp->private_data;
|
|
|
|
if (trace_flags & TRACE_ITER_BLOCK) {
|
|
/*
|
|
* Always select as readable when in blocking mode
|
|
*/
|
|
return POLLIN | POLLRDNORM;
|
|
} else {
|
|
if (!trace_empty(iter))
|
|
return POLLIN | POLLRDNORM;
|
|
poll_wait(filp, &trace_wait, poll_table);
|
|
if (!trace_empty(iter))
|
|
return POLLIN | POLLRDNORM;
|
|
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Consumer reader.
|
|
*/
|
|
static ssize_t
|
|
tracing_read_pipe(struct file *filp, char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
struct trace_iterator *iter = filp->private_data;
|
|
ssize_t sret;
|
|
|
|
/* return any leftover data */
|
|
sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
|
|
if (sret != -EBUSY)
|
|
return sret;
|
|
|
|
trace_seq_reset(&iter->seq);
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
if (iter->trace->read) {
|
|
sret = iter->trace->read(iter, filp, ubuf, cnt, ppos);
|
|
if (sret)
|
|
goto out;
|
|
}
|
|
|
|
waitagain:
|
|
sret = 0;
|
|
while (trace_empty(iter)) {
|
|
|
|
if ((filp->f_flags & O_NONBLOCK)) {
|
|
sret = -EAGAIN;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* This is a make-shift waitqueue. The reason we don't use
|
|
* an actual wait queue is because:
|
|
* 1) we only ever have one waiter
|
|
* 2) the tracing, traces all functions, we don't want
|
|
* the overhead of calling wake_up and friends
|
|
* (and tracing them too)
|
|
* Anyway, this is really very primitive wakeup.
|
|
*/
|
|
set_current_state(TASK_INTERRUPTIBLE);
|
|
iter->tr->waiter = current;
|
|
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
/* sleep for 100 msecs, and try again. */
|
|
schedule_timeout(HZ/10);
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
|
|
iter->tr->waiter = NULL;
|
|
|
|
if (signal_pending(current)) {
|
|
sret = -EINTR;
|
|
goto out;
|
|
}
|
|
|
|
if (iter->trace != current_trace)
|
|
goto out;
|
|
|
|
/*
|
|
* We block until we read something and tracing is disabled.
|
|
* We still block if tracing is disabled, but we have never
|
|
* read anything. This allows a user to cat this file, and
|
|
* then enable tracing. But after we have read something,
|
|
* we give an EOF when tracing is again disabled.
|
|
*
|
|
* iter->pos will be 0 if we haven't read anything.
|
|
*/
|
|
if (!tracer_enabled && iter->pos)
|
|
break;
|
|
|
|
continue;
|
|
}
|
|
|
|
/* stop when tracing is finished */
|
|
if (trace_empty(iter))
|
|
goto out;
|
|
|
|
if (cnt >= PAGE_SIZE)
|
|
cnt = PAGE_SIZE - 1;
|
|
|
|
/* reset all but tr, trace, and overruns */
|
|
memset(&iter->seq, 0,
|
|
sizeof(struct trace_iterator) -
|
|
offsetof(struct trace_iterator, seq));
|
|
iter->pos = -1;
|
|
|
|
while (find_next_entry_inc(iter) != NULL) {
|
|
enum print_line_t ret;
|
|
int len = iter->seq.len;
|
|
|
|
ret = print_trace_line(iter);
|
|
if (ret == TRACE_TYPE_PARTIAL_LINE) {
|
|
/* don't print partial lines */
|
|
iter->seq.len = len;
|
|
break;
|
|
}
|
|
|
|
trace_consume(iter);
|
|
|
|
if (iter->seq.len >= cnt)
|
|
break;
|
|
}
|
|
|
|
/* Now copy what we have to the user */
|
|
sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
|
|
if (iter->seq.readpos >= iter->seq.len)
|
|
trace_seq_reset(&iter->seq);
|
|
|
|
/*
|
|
* If there was nothing to send to user, inspite of consuming trace
|
|
* entries, go back to wait for more entries.
|
|
*/
|
|
if (sret == -EBUSY)
|
|
goto waitagain;
|
|
|
|
out:
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
return sret;
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_entries_read(struct file *filp, char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
struct trace_array *tr = filp->private_data;
|
|
char buf[64];
|
|
int r;
|
|
|
|
r = sprintf(buf, "%lu\n", tr->entries >> 10);
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_entries_write(struct file *filp, const char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
unsigned long val;
|
|
char buf[64];
|
|
int ret, cpu;
|
|
|
|
if (cnt >= sizeof(buf))
|
|
return -EINVAL;
|
|
|
|
if (copy_from_user(&buf, ubuf, cnt))
|
|
return -EFAULT;
|
|
|
|
buf[cnt] = 0;
|
|
|
|
ret = strict_strtoul(buf, 10, &val);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
/* must have at least 1 entry */
|
|
if (!val)
|
|
return -EINVAL;
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
|
|
tracing_stop();
|
|
|
|
/* disable all cpu buffers */
|
|
for_each_tracing_cpu(cpu) {
|
|
if (global_trace.data[cpu])
|
|
atomic_inc(&global_trace.data[cpu]->disabled);
|
|
if (max_tr.data[cpu])
|
|
atomic_inc(&max_tr.data[cpu]->disabled);
|
|
}
|
|
|
|
/* value is in KB */
|
|
val <<= 10;
|
|
|
|
if (val != global_trace.entries) {
|
|
ret = ring_buffer_resize(global_trace.buffer, val);
|
|
if (ret < 0) {
|
|
cnt = ret;
|
|
goto out;
|
|
}
|
|
|
|
ret = ring_buffer_resize(max_tr.buffer, val);
|
|
if (ret < 0) {
|
|
int r;
|
|
cnt = ret;
|
|
r = ring_buffer_resize(global_trace.buffer,
|
|
global_trace.entries);
|
|
if (r < 0) {
|
|
/* AARGH! We are left with different
|
|
* size max buffer!!!! */
|
|
WARN_ON(1);
|
|
tracing_disabled = 1;
|
|
}
|
|
goto out;
|
|
}
|
|
|
|
global_trace.entries = val;
|
|
}
|
|
|
|
filp->f_pos += cnt;
|
|
|
|
/* If check pages failed, return ENOMEM */
|
|
if (tracing_disabled)
|
|
cnt = -ENOMEM;
|
|
out:
|
|
for_each_tracing_cpu(cpu) {
|
|
if (global_trace.data[cpu])
|
|
atomic_dec(&global_trace.data[cpu]->disabled);
|
|
if (max_tr.data[cpu])
|
|
atomic_dec(&max_tr.data[cpu]->disabled);
|
|
}
|
|
|
|
tracing_start();
|
|
max_tr.entries = global_trace.entries;
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
return cnt;
|
|
}
|
|
|
|
static int mark_printk(const char *fmt, ...)
|
|
{
|
|
int ret;
|
|
va_list args;
|
|
va_start(args, fmt);
|
|
ret = trace_vprintk(0, -1, fmt, args);
|
|
va_end(args);
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_mark_write(struct file *filp, const char __user *ubuf,
|
|
size_t cnt, loff_t *fpos)
|
|
{
|
|
char *buf;
|
|
char *end;
|
|
|
|
if (tracing_disabled)
|
|
return -EINVAL;
|
|
|
|
if (cnt > TRACE_BUF_SIZE)
|
|
cnt = TRACE_BUF_SIZE;
|
|
|
|
buf = kmalloc(cnt + 1, GFP_KERNEL);
|
|
if (buf == NULL)
|
|
return -ENOMEM;
|
|
|
|
if (copy_from_user(buf, ubuf, cnt)) {
|
|
kfree(buf);
|
|
return -EFAULT;
|
|
}
|
|
|
|
/* Cut from the first nil or newline. */
|
|
buf[cnt] = '\0';
|
|
end = strchr(buf, '\n');
|
|
if (end)
|
|
*end = '\0';
|
|
|
|
cnt = mark_printk("%s\n", buf);
|
|
kfree(buf);
|
|
*fpos += cnt;
|
|
|
|
return cnt;
|
|
}
|
|
|
|
static struct file_operations tracing_max_lat_fops = {
|
|
.open = tracing_open_generic,
|
|
.read = tracing_max_lat_read,
|
|
.write = tracing_max_lat_write,
|
|
};
|
|
|
|
static struct file_operations tracing_ctrl_fops = {
|
|
.open = tracing_open_generic,
|
|
.read = tracing_ctrl_read,
|
|
.write = tracing_ctrl_write,
|
|
};
|
|
|
|
static struct file_operations set_tracer_fops = {
|
|
.open = tracing_open_generic,
|
|
.read = tracing_set_trace_read,
|
|
.write = tracing_set_trace_write,
|
|
};
|
|
|
|
static struct file_operations tracing_pipe_fops = {
|
|
.open = tracing_open_pipe,
|
|
.poll = tracing_poll_pipe,
|
|
.read = tracing_read_pipe,
|
|
.release = tracing_release_pipe,
|
|
};
|
|
|
|
static struct file_operations tracing_entries_fops = {
|
|
.open = tracing_open_generic,
|
|
.read = tracing_entries_read,
|
|
.write = tracing_entries_write,
|
|
};
|
|
|
|
static struct file_operations tracing_mark_fops = {
|
|
.open = tracing_open_generic,
|
|
.write = tracing_mark_write,
|
|
};
|
|
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
|
|
int __weak ftrace_arch_read_dyn_info(char *buf, int size)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_read_dyn_info(struct file *filp, char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
static char ftrace_dyn_info_buffer[1024];
|
|
static DEFINE_MUTEX(dyn_info_mutex);
|
|
unsigned long *p = filp->private_data;
|
|
char *buf = ftrace_dyn_info_buffer;
|
|
int size = ARRAY_SIZE(ftrace_dyn_info_buffer);
|
|
int r;
|
|
|
|
mutex_lock(&dyn_info_mutex);
|
|
r = sprintf(buf, "%ld ", *p);
|
|
|
|
r += ftrace_arch_read_dyn_info(buf+r, (size-1)-r);
|
|
buf[r++] = '\n';
|
|
|
|
r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
|
|
|
|
mutex_unlock(&dyn_info_mutex);
|
|
|
|
return r;
|
|
}
|
|
|
|
static struct file_operations tracing_dyn_info_fops = {
|
|
.open = tracing_open_generic,
|
|
.read = tracing_read_dyn_info,
|
|
};
|
|
#endif
|
|
|
|
static struct dentry *d_tracer;
|
|
|
|
struct dentry *tracing_init_dentry(void)
|
|
{
|
|
static int once;
|
|
|
|
if (d_tracer)
|
|
return d_tracer;
|
|
|
|
d_tracer = debugfs_create_dir("tracing", NULL);
|
|
|
|
if (!d_tracer && !once) {
|
|
once = 1;
|
|
pr_warning("Could not create debugfs directory 'tracing'\n");
|
|
return NULL;
|
|
}
|
|
|
|
return d_tracer;
|
|
}
|
|
|
|
#ifdef CONFIG_FTRACE_SELFTEST
|
|
/* Let selftest have access to static functions in this file */
|
|
#include "trace_selftest.c"
|
|
#endif
|
|
|
|
static __init int tracer_init_debugfs(void)
|
|
{
|
|
struct dentry *d_tracer;
|
|
struct dentry *entry;
|
|
|
|
d_tracer = tracing_init_dentry();
|
|
|
|
entry = debugfs_create_file("tracing_enabled", 0644, d_tracer,
|
|
&global_trace, &tracing_ctrl_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs 'tracing_enabled' entry\n");
|
|
|
|
entry = debugfs_create_file("trace_options", 0644, d_tracer,
|
|
NULL, &tracing_iter_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs 'trace_options' entry\n");
|
|
|
|
entry = debugfs_create_file("tracing_cpumask", 0644, d_tracer,
|
|
NULL, &tracing_cpumask_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs 'tracing_cpumask' entry\n");
|
|
|
|
entry = debugfs_create_file("latency_trace", 0444, d_tracer,
|
|
&global_trace, &tracing_lt_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs 'latency_trace' entry\n");
|
|
|
|
entry = debugfs_create_file("trace", 0444, d_tracer,
|
|
&global_trace, &tracing_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs 'trace' entry\n");
|
|
|
|
entry = debugfs_create_file("available_tracers", 0444, d_tracer,
|
|
&global_trace, &show_traces_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs 'available_tracers' entry\n");
|
|
|
|
entry = debugfs_create_file("current_tracer", 0444, d_tracer,
|
|
&global_trace, &set_tracer_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs 'current_tracer' entry\n");
|
|
|
|
entry = debugfs_create_file("tracing_max_latency", 0644, d_tracer,
|
|
&tracing_max_latency,
|
|
&tracing_max_lat_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs "
|
|
"'tracing_max_latency' entry\n");
|
|
|
|
entry = debugfs_create_file("tracing_thresh", 0644, d_tracer,
|
|
&tracing_thresh, &tracing_max_lat_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs "
|
|
"'tracing_thresh' entry\n");
|
|
entry = debugfs_create_file("README", 0644, d_tracer,
|
|
NULL, &tracing_readme_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs 'README' entry\n");
|
|
|
|
entry = debugfs_create_file("trace_pipe", 0644, d_tracer,
|
|
NULL, &tracing_pipe_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs "
|
|
"'trace_pipe' entry\n");
|
|
|
|
entry = debugfs_create_file("buffer_size_kb", 0644, d_tracer,
|
|
&global_trace, &tracing_entries_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs "
|
|
"'buffer_size_kb' entry\n");
|
|
|
|
entry = debugfs_create_file("trace_marker", 0220, d_tracer,
|
|
NULL, &tracing_mark_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs "
|
|
"'trace_marker' entry\n");
|
|
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
entry = debugfs_create_file("dyn_ftrace_total_info", 0444, d_tracer,
|
|
&ftrace_update_tot_cnt,
|
|
&tracing_dyn_info_fops);
|
|
if (!entry)
|
|
pr_warning("Could not create debugfs "
|
|
"'dyn_ftrace_total_info' entry\n");
|
|
#endif
|
|
#ifdef CONFIG_SYSPROF_TRACER
|
|
init_tracer_sysprof_debugfs(d_tracer);
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
int trace_vprintk(unsigned long ip, int depth, const char *fmt, va_list args)
|
|
{
|
|
static DEFINE_SPINLOCK(trace_buf_lock);
|
|
static char trace_buf[TRACE_BUF_SIZE];
|
|
|
|
struct ring_buffer_event *event;
|
|
struct trace_array *tr = &global_trace;
|
|
struct trace_array_cpu *data;
|
|
int cpu, len = 0, size, pc;
|
|
struct print_entry *entry;
|
|
unsigned long irq_flags;
|
|
|
|
if (tracing_disabled || tracing_selftest_running)
|
|
return 0;
|
|
|
|
pc = preempt_count();
|
|
preempt_disable_notrace();
|
|
cpu = raw_smp_processor_id();
|
|
data = tr->data[cpu];
|
|
|
|
if (unlikely(atomic_read(&data->disabled)))
|
|
goto out;
|
|
|
|
pause_graph_tracing();
|
|
spin_lock_irqsave(&trace_buf_lock, irq_flags);
|
|
len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
|
|
|
|
len = min(len, TRACE_BUF_SIZE-1);
|
|
trace_buf[len] = 0;
|
|
|
|
size = sizeof(*entry) + len + 1;
|
|
event = ring_buffer_lock_reserve(tr->buffer, size, &irq_flags);
|
|
if (!event)
|
|
goto out_unlock;
|
|
entry = ring_buffer_event_data(event);
|
|
tracing_generic_entry_update(&entry->ent, irq_flags, pc);
|
|
entry->ent.type = TRACE_PRINT;
|
|
entry->ip = ip;
|
|
entry->depth = depth;
|
|
|
|
memcpy(&entry->buf, trace_buf, len);
|
|
entry->buf[len] = 0;
|
|
ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
|
|
|
|
out_unlock:
|
|
spin_unlock_irqrestore(&trace_buf_lock, irq_flags);
|
|
unpause_graph_tracing();
|
|
out:
|
|
preempt_enable_notrace();
|
|
|
|
return len;
|
|
}
|
|
EXPORT_SYMBOL_GPL(trace_vprintk);
|
|
|
|
int __ftrace_printk(unsigned long ip, const char *fmt, ...)
|
|
{
|
|
int ret;
|
|
va_list ap;
|
|
|
|
if (!(trace_flags & TRACE_ITER_PRINTK))
|
|
return 0;
|
|
|
|
va_start(ap, fmt);
|
|
ret = trace_vprintk(ip, task_curr_ret_stack(current), fmt, ap);
|
|
va_end(ap);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__ftrace_printk);
|
|
|
|
static int trace_panic_handler(struct notifier_block *this,
|
|
unsigned long event, void *unused)
|
|
{
|
|
if (ftrace_dump_on_oops)
|
|
ftrace_dump();
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
static struct notifier_block trace_panic_notifier = {
|
|
.notifier_call = trace_panic_handler,
|
|
.next = NULL,
|
|
.priority = 150 /* priority: INT_MAX >= x >= 0 */
|
|
};
|
|
|
|
static int trace_die_handler(struct notifier_block *self,
|
|
unsigned long val,
|
|
void *data)
|
|
{
|
|
switch (val) {
|
|
case DIE_OOPS:
|
|
if (ftrace_dump_on_oops)
|
|
ftrace_dump();
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
static struct notifier_block trace_die_notifier = {
|
|
.notifier_call = trace_die_handler,
|
|
.priority = 200
|
|
};
|
|
|
|
/*
|
|
* printk is set to max of 1024, we really don't need it that big.
|
|
* Nothing should be printing 1000 characters anyway.
|
|
*/
|
|
#define TRACE_MAX_PRINT 1000
|
|
|
|
/*
|
|
* Define here KERN_TRACE so that we have one place to modify
|
|
* it if we decide to change what log level the ftrace dump
|
|
* should be at.
|
|
*/
|
|
#define KERN_TRACE KERN_INFO
|
|
|
|
static void
|
|
trace_printk_seq(struct trace_seq *s)
|
|
{
|
|
/* Probably should print a warning here. */
|
|
if (s->len >= 1000)
|
|
s->len = 1000;
|
|
|
|
/* should be zero ended, but we are paranoid. */
|
|
s->buffer[s->len] = 0;
|
|
|
|
printk(KERN_TRACE "%s", s->buffer);
|
|
|
|
trace_seq_reset(s);
|
|
}
|
|
|
|
void ftrace_dump(void)
|
|
{
|
|
static DEFINE_SPINLOCK(ftrace_dump_lock);
|
|
/* use static because iter can be a bit big for the stack */
|
|
static struct trace_iterator iter;
|
|
static cpumask_t mask;
|
|
static int dump_ran;
|
|
unsigned long flags;
|
|
int cnt = 0, cpu;
|
|
|
|
/* only one dump */
|
|
spin_lock_irqsave(&ftrace_dump_lock, flags);
|
|
if (dump_ran)
|
|
goto out;
|
|
|
|
dump_ran = 1;
|
|
|
|
/* No turning back! */
|
|
ftrace_kill();
|
|
|
|
for_each_tracing_cpu(cpu) {
|
|
atomic_inc(&global_trace.data[cpu]->disabled);
|
|
}
|
|
|
|
/* don't look at user memory in panic mode */
|
|
trace_flags &= ~TRACE_ITER_SYM_USEROBJ;
|
|
|
|
printk(KERN_TRACE "Dumping ftrace buffer:\n");
|
|
|
|
iter.tr = &global_trace;
|
|
iter.trace = current_trace;
|
|
|
|
/*
|
|
* We need to stop all tracing on all CPUS to read the
|
|
* the next buffer. This is a bit expensive, but is
|
|
* not done often. We fill all what we can read,
|
|
* and then release the locks again.
|
|
*/
|
|
|
|
cpus_clear(mask);
|
|
|
|
while (!trace_empty(&iter)) {
|
|
|
|
if (!cnt)
|
|
printk(KERN_TRACE "---------------------------------\n");
|
|
|
|
cnt++;
|
|
|
|
/* reset all but tr, trace, and overruns */
|
|
memset(&iter.seq, 0,
|
|
sizeof(struct trace_iterator) -
|
|
offsetof(struct trace_iterator, seq));
|
|
iter.iter_flags |= TRACE_FILE_LAT_FMT;
|
|
iter.pos = -1;
|
|
|
|
if (find_next_entry_inc(&iter) != NULL) {
|
|
print_trace_line(&iter);
|
|
trace_consume(&iter);
|
|
}
|
|
|
|
trace_printk_seq(&iter.seq);
|
|
}
|
|
|
|
if (!cnt)
|
|
printk(KERN_TRACE " (ftrace buffer empty)\n");
|
|
else
|
|
printk(KERN_TRACE "---------------------------------\n");
|
|
|
|
out:
|
|
spin_unlock_irqrestore(&ftrace_dump_lock, flags);
|
|
}
|
|
|
|
__init static int tracer_alloc_buffers(void)
|
|
{
|
|
struct trace_array_cpu *data;
|
|
int i;
|
|
|
|
/* TODO: make the number of buffers hot pluggable with CPUS */
|
|
tracing_buffer_mask = cpu_possible_map;
|
|
|
|
global_trace.buffer = ring_buffer_alloc(trace_buf_size,
|
|
TRACE_BUFFER_FLAGS);
|
|
if (!global_trace.buffer) {
|
|
printk(KERN_ERR "tracer: failed to allocate ring buffer!\n");
|
|
WARN_ON(1);
|
|
return 0;
|
|
}
|
|
global_trace.entries = ring_buffer_size(global_trace.buffer);
|
|
|
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
|
max_tr.buffer = ring_buffer_alloc(trace_buf_size,
|
|
TRACE_BUFFER_FLAGS);
|
|
if (!max_tr.buffer) {
|
|
printk(KERN_ERR "tracer: failed to allocate max ring buffer!\n");
|
|
WARN_ON(1);
|
|
ring_buffer_free(global_trace.buffer);
|
|
return 0;
|
|
}
|
|
max_tr.entries = ring_buffer_size(max_tr.buffer);
|
|
WARN_ON(max_tr.entries != global_trace.entries);
|
|
#endif
|
|
|
|
/* Allocate the first page for all buffers */
|
|
for_each_tracing_cpu(i) {
|
|
data = global_trace.data[i] = &per_cpu(global_trace_cpu, i);
|
|
max_tr.data[i] = &per_cpu(max_data, i);
|
|
}
|
|
|
|
trace_init_cmdlines();
|
|
|
|
register_tracer(&nop_trace);
|
|
#ifdef CONFIG_BOOT_TRACER
|
|
register_tracer(&boot_tracer);
|
|
current_trace = &boot_tracer;
|
|
current_trace->init(&global_trace);
|
|
#else
|
|
current_trace = &nop_trace;
|
|
#endif
|
|
|
|
/* All seems OK, enable tracing */
|
|
tracing_disabled = 0;
|
|
|
|
atomic_notifier_chain_register(&panic_notifier_list,
|
|
&trace_panic_notifier);
|
|
|
|
register_die_notifier(&trace_die_notifier);
|
|
|
|
return 0;
|
|
}
|
|
early_initcall(tracer_alloc_buffers);
|
|
fs_initcall(tracer_init_debugfs);
|