/*

* trace_output.c

*

* Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>

*

*/

#include <linux/module.h>

#include <linux/mutex.h>

#include <linux/ftrace.h>

#include "trace_output.h"

/* must be a power of 2 */

#define EVENT_HASHSIZE 128

DECLARE_RWSEM(trace_event_mutex);

static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly;

static int next_event_type = __TRACE_LAST_TYPE + 1;

int trace_print_seq(struct seq_file *m, struct trace_seq *s)

{

int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len;

int ret;

ret = seq_write(m, s->buffer, len);

/*

* Only reset this buffer if we successfully wrote to the

* seq_file buffer.

*/

if (!ret)

trace_seq_init(s);

return ret;

}

enum print_line_t trace_print_bprintk_msg_only(struct trace_iterator *iter)

{

struct trace_seq *s = &iter->seq;

struct trace_entry *entry = iter->ent;

struct bprint_entry *field;

int ret;

trace_assign_type(field, entry);

ret = trace_seq_bprintf(s, field->fmt, field->buf);

if (!ret)

return TRACE_TYPE_PARTIAL_LINE;

return TRACE_TYPE_HANDLED;

}

enum print_line_t trace_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, "%s", field->buf);

if (!ret)

return TRACE_TYPE_PARTIAL_LINE;

return TRACE_TYPE_HANDLED;

}

/**

* trace_seq_printf - sequence printing of trace information

* @s: trace sequence descriptor

* @fmt: printf format string

*

* It returns 0 if the trace oversizes the buffer's free

* space, 1 otherwise.

*

* 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 (s->full || !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) {

s->full = 1;

return 0;

}

s->len += ret;

return 1;

}

EXPORT_SYMBOL_GPL(trace_seq_printf);

/**

* trace_seq_vprintf - 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_vprintf(struct trace_seq *s, const char *fmt, va_list args)

{

int len = (PAGE_SIZE - 1) - s->len;

int ret;

if (s->full || !len)

return 0;

ret = vsnprintf(s->buffer + s->len, len, fmt, args);

/* If we can't write it all, don't bother writing anything */

if (ret >= len) {

s->full = 1;

return 0;

}

s->len += ret;

return len;

}

EXPORT_SYMBOL_GPL(trace_seq_vprintf);

int trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary)

{

int len = (PAGE_SIZE - 1) - s->len;

int ret;

if (s->full || !len)

return 0;

ret = bstr_printf(s->buffer + s->len, len, fmt, binary);

/* If we can't write it all, don't bother writing anything */

if (ret >= len) {

s->full = 1;

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.

*/

int trace_seq_puts(struct trace_seq *s, const char *str)

{

int len = strlen(str);

if (s->full)

return 0;

if (len > ((PAGE_SIZE - 1) - s->len)) {

s->full = 1;

return 0;

}

memcpy(s->buffer + s->len, str, len);

s->len += len;

return len;

}

int trace_seq_putc(struct trace_seq *s, unsigned char c)

{

if (s->full)

return 0;

if (s->len >= (PAGE_SIZE - 1)) {

s->full = 1;

return 0;

}

s->buffer[s->len++] = c;

return 1;

}

EXPORT_SYMBOL(trace_seq_putc);

int trace_seq_putmem(struct trace_seq *s, const void *mem, size_t len)

{

if (s->full)

return 0;

if (len > ((PAGE_SIZE - 1) - s->len)) {

s->full = 1;

return 0;

}

memcpy(s->buffer + s->len, mem, len);

s->len += len;

return len;

}

int trace_seq_putmem_hex(struct trace_seq *s, const void *mem, size_t len)

{

unsigned char hex[HEX_CHARS];

const unsigned char *data = mem;

int i, j;

if (s->full)

return 0;

#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);

}

void *trace_seq_reserve(struct trace_seq *s, size_t len)

{

void *ret;

if (s->full)

return NULL;

if (len > ((PAGE_SIZE - 1) - s->len)) {

s->full = 1;

return NULL;

}

ret = s->buffer + s->len;

s->len += len;

return ret;

}

int trace_seq_path(struct trace_seq *s, const struct path *path)

{

unsigned char *p;

if (s->full)

return 0;

if (s->len >= (PAGE_SIZE - 1)) {

s->full = 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;

}

s->full = 1;

return 0;

}

const char *

ftrace_print_flags_seq(struct trace_seq *p, const char *delim,

unsigned long flags,

const struct trace_print_flags *flag_array)

{

unsigned long mask;

const char *str;

const char *ret = p->buffer + p->len;

int i, first = 1;

for (i = 0; flag_array[i].name && flags; i++) {

mask = flag_array[i].mask;

if ((flags & mask) != mask)

continue;

str = flag_array[i].name;

flags &= ~mask;

if (!first && delim)

trace_seq_puts(p, delim);

else

first = 0;

trace_seq_puts(p, str);

}

/* check for left over flags */

if (flags) {

if (!first && delim)

trace_seq_puts(p, delim);

trace_seq_printf(p, "0x%lx", flags);

}

trace_seq_putc(p, 0);

return ret;

}

EXPORT_SYMBOL(ftrace_print_flags_seq);

const char *

ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val,

const struct trace_print_flags *symbol_array)

{

int i;

const char *ret = p->buffer + p->len;

for (i = 0; symbol_array[i].name; i++) {

if (val != symbol_array[i].mask)

continue;

trace_seq_puts(p, symbol_array[i].name);

break;

}

if (ret == (const char *)(p->buffer + p->len))

trace_seq_printf(p, "0x%lx", val);

trace_seq_putc(p, 0);

return ret;

}

EXPORT_SYMBOL(ftrace_print_symbols_seq);

#if BITS_PER_LONG == 32

const char *

ftrace_print_symbols_seq_u64(struct trace_seq *p, unsigned long long val,

const struct trace_print_flags_u64 *symbol_array)

{

int i;

const char *ret = p->buffer + p->len;

for (i = 0; symbol_array[i].name; i++) {

if (val != symbol_array[i].mask)

continue;

trace_seq_puts(p, symbol_array[i].name);

break;

}

if (ret == (const char *)(p->buffer + p->len))

trace_seq_printf(p, "0x%llx", val);

trace_seq_putc(p, 0);

return ret;

}

EXPORT_SYMBOL(ftrace_print_symbols_seq_u64);

#endif

const char *

ftrace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len)

{

int i;

const char *ret = p->buffer + p->len;

for (i = 0; i < buf_len; i++)

trace_seq_printf(p, "%s%2.2x", i == 0 ? "" : " ", buf[i]);

trace_seq_putc(p, 0);

return ret;

}

EXPORT_SYMBOL(ftrace_print_hex_seq);

#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_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 (s->full)

return 0;

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;

}

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->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 (ret)

ret = trace_seq_puts(s, " => ");

if (!ip) {

if (ret)

ret = trace_seq_puts(s, "??");

if (ret)

ret = trace_seq_puts(s, "\n");

continue;

}

if (!ret)

break;

if (ret)

ret = seq_print_user_ip(s, mm, ip, sym_flags);

ret = trace_seq_puts(s, "\n");

}

if (mm)

mmput(mm);

return ret;

}

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;

}

/**

* trace_print_lat_fmt - print the irq, preempt and lockdep fields

* @s: trace seq struct to write to

* @entry: The trace entry field from the ring buffer

*

* Prints the generic fields of irqs off, in hard or softirq, preempt

* count.

*/

int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)

{

char hardsoft_irq;

char need_resched;

char irqs_off;

int hardirq;

int softirq;

int ret;

hardirq = entry->flags & TRACE_FLAG_HARDIRQ;

softirq = entry->flags & TRACE_FLAG_SOFTIRQ;

irqs_off =

(entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :

(entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' :

'.';

need_resched =

(entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.';

hardsoft_irq =

(hardirq && softirq) ? 'H' :

hardirq ? 'h' :

softirq ? 's' :

'.';

if (!trace_seq_printf(s, "%c%c%c",

irqs_off, need_resched, hardsoft_irq))

return 0;

if (entry->preempt_count)

ret = trace_seq_printf(s, "%x", entry->preempt_count);

else

ret = trace_seq_putc(s, '.');

return ret;

}

static int

lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)

{

char comm[TASK_COMM_LEN];

trace_find_cmdline(entry->pid, comm);

if (!trace_seq_printf(s, "%8.8s-%-5d %3d",

comm, entry->pid, cpu))

return 0;

return trace_print_lat_fmt(s, entry);

}

static unsigned long preempt_mark_thresh = 100;

static int

lat_print_timestamp(struct trace_seq *s, u64 abs_usecs,

unsigned long rel_usecs)

{

return trace_seq_printf(s, " %4lldus%c: ", abs_usecs,

rel_usecs > preempt_mark_thresh ? '!' :

rel_usecs > 1 ? '+' : ' ');

}

int trace_print_context(struct trace_iterator *iter)

{

struct trace_seq *s = &iter->seq;

struct trace_entry *entry = iter->ent;

unsigned long long t = ns2usecs(iter->ts);

unsigned long usec_rem = do_div(t, USEC_PER_SEC);

unsigned long secs = (unsigned long)t;

char comm[TASK_COMM_LEN];

int ret;

trace_find_cmdline(entry->pid, comm);

ret = trace_seq_printf(s, "%16s-%-5d [%03d] ",

comm, entry->pid, iter->cpu);

if (!ret)

return 0;

if (trace_flags & TRACE_ITER_IRQ_INFO) {

ret = trace_print_lat_fmt(s, entry);

if (!ret)

return 0;

}

return trace_seq_printf(s, " %5lu.%06lu: ",

secs, usec_rem);

}

int trace_print_lat_context(struct trace_iterator *iter)

{

u64 next_ts;

int ret;

/* trace_find_next_entry will reset ent_size */

int ent_size = iter->ent_size;

struct trace_seq *s = &iter->seq;

struct trace_entry *entry = iter->ent,

*next_entry = trace_find_next_entry(iter, NULL,

&next_ts);

unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE);

unsigned long abs_usecs = ns2usecs(iter->ts - iter->tr->time_start);

unsigned long rel_usecs;

/* Restore the original ent_size */

iter->ent_size = ent_size;

if (!next_entry)

next_ts = iter->ts;

rel_usecs = ns2usecs(next_ts - iter->ts);

if (verbose) {

char comm[TASK_COMM_LEN];

trace_find_cmdline(entry->pid, comm);

ret = trace_seq_printf(s, "%16s %5d %3d %d %08x %08lx [%08llx]"

" %ld.%03ldms (+%ld.%03ldms): ", comm,

entry->pid, iter->cpu, entry->flags,

entry->preempt_count, iter->idx,

ns2usecs(iter->ts),

abs_usecs / USEC_PER_MSEC,

abs_usecs % USEC_PER_MSEC,

rel_usecs / USEC_PER_MSEC,

rel_usecs % USEC_PER_MSEC);

} else {

ret = lat_print_generic(s, entry, iter->cpu);

if (ret)

ret = lat_print_timestamp(s, abs_usecs, rel_usecs);

}

return ret;

}

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] : '?';

}

/**

* ftrace_find_event - find a registered event

* @type: the type of event to look for

*

* Returns an event of type @type otherwise NULL

* Called with trace_event_read_lock() held.

*/

struct trace_event *ftrace_find_event(int type)

{

struct trace_event *event;

struct hlist_node *n;

unsigned key;

key = type & (EVENT_HASHSIZE - 1);

hlist_for_each_entry(event, n, &event_hash[key], node) {

if (event->type == type)

return event;

}

return NULL;

}

static LIST_HEAD(ftrace_event_list);

static int trace_search_list(struct list_head **list)

{

struct trace_event *e;

int last = __TRACE_LAST_TYPE;

if (list_empty(&ftrace_event_list)) {

*list = &ftrace_event_list;

return last + 1;

}

/*

* We used up all possible max events,

* lets see if somebody freed one.

*/

list_for_each_entry(e, &ftrace_event_list, list) {

if (e->type != last + 1)

break;

last++;

}

/* Did we used up all 65 thousand events??? */

if ((last + 1) > FTRACE_MAX_EVENT)

return 0;

*list = &e->list;

return last + 1;

}

void trace_event_read_lock(void)

{

down_read(&trace_event_mutex);

}

void trace_event_read_unlock(void)

{

up_read(&trace_event_mutex);

}

/**

* register_ftrace_event - register output for an event type

* @event: the event type to register

*

* Event types are stored in a hash and this hash is used to

* find a way to print an event. If the @event->type is set

* then it will use that type, otherwise it will assign a

* type to use.

*

* If you assign your own type, please make sure it is added

* to the trace_type enum in trace.h, to avoid collisions

* with the dynamic types.

*

* Returns the event type number or zero on error.

*/

int register_ftrace_event(struct trace_event *event)

{

unsigned key;

int ret = 0;

down_write(&trace_event_mutex);

if (WARN_ON(!event))

goto out;

if (WARN_ON(!event->funcs))

goto out;

INIT_LIST_HEAD(&event->list);

if (!event->type) {

struct list_head *list = NULL;

if (next_event_type > FTRACE_MAX_EVENT) {

event->type = trace_search_list(&list);

if (!event->type)

goto out;

} else {

event->type = next_event_type++;

list = &ftrace_event_list;

}

if (WARN_ON(ftrace_find_event(event->type)))

goto out;

list_add_tail(&event->list, list);

} else if (event->type > __TRACE_LAST_TYPE) {

printk(KERN_WARNING "Need to add type to trace.h\n");

WARN_ON(1);

goto out;

} else {

/* Is this event already used */

if (ftrace_find_event(event->type))

goto out;

}

if (event->funcs->trace == NULL)

event->funcs->trace = trace_nop_print;

if (event->funcs->raw == NULL)

event->funcs->raw = trace_nop_print;

if (event->funcs->hex == NULL)

event->funcs->hex = trace_nop_print;

if (event->funcs->binary == NULL)

event->funcs->binary = trace_nop_print;

key = event->type & (EVENT_HASHSIZE - 1);

hlist_add_head(&event->node, &event_hash[key]);

ret = event->type;

out:

up_write(&trace_event_mutex);

return ret;

}

EXPORT_SYMBOL_GPL(register_ftrace_event);

/*

* Used by module code with the trace_event_mutex held for write.

*/

int __unregister_ftrace_event(struct trace_event *event)

{

hlist_del(&event->node);

list_del(&event->list);

return 0;

}

/**

* unregister_ftrace_event - remove a no longer used event

* @event: the event to remove

*/

int unregister_ftrace_event(struct trace_event *event)

{

down_write(&trace_event_mutex);

__unregister_ftrace_event(event);

up_write(&trace_event_mutex);

return 0;

}

EXPORT_SYMBOL_GPL(unregister_ftrace_event);

/*

* Standard events

*/

enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,

struct trace_event *event)

{

if (!trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type))

return TRACE_TYPE_PARTIAL_LINE;

return TRACE_TYPE_HANDLED;

}

/* TRACE_FN */

static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,

struct trace_event *event)

{

struct ftrace_entry *field;

struct trace_seq *s = &iter->seq;

trace_assign_type(field, iter->ent);

if (!seq_print_ip_sym(s, field->ip, flags))

goto partial;

if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {

if (!trace_seq_printf(s, " <-"))

goto partial;

if (!seq_print_ip_sym(s,

field->parent_ip,

flags))

goto partial;

}

if (!trace_seq_printf(s, "\n"))

goto partial;

return TRACE_TYPE_HANDLED;

partial:

return TRACE_TYPE_PARTIAL_LINE;

}

static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,

struct trace_event *event)

{

struct ftrace_entry *field;

trace_assign_type(field, iter->ent);

if (!trace_seq_printf(&iter->seq, "%lx %lx\n",

field->ip,

field->parent_ip))

return TRACE_TYPE_PARTIAL_LINE;

return TRACE_TYPE_HANDLED;

}

static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,

struct trace_event *event)

{

struct ftrace_entry *field;

struct trace_seq *s = &iter->seq;

trace_assign_type(field, iter->ent);

SEQ_PUT_HEX_FIELD_RET(s, field->ip);

SEQ_PUT_HEX_FIELD_RET(s, field->parent_ip);

return TRACE_TYPE_HANDLED;

}

static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,

struct trace_event *event)

{

struct ftrace_entry *field;

struct trace_seq *s = &iter->seq;

trace_assign_type(field, iter->ent);

SEQ_PUT_FIELD_RET(s, field->ip);

SEQ_PUT_FIELD_RET(s, field->parent_ip);

return TRACE_TYPE_HANDLED;

}

static struct trace_event_functions trace_fn_funcs = {

.trace = trace_fn_trace,

.raw = trace_fn_raw,

.hex = trace_fn_hex,

.binary = trace_fn_bin,

};

static struct trace_event trace_fn_event = {

.type = TRACE_FN,

.funcs = &trace_fn_funcs,

};

/* TRACE_CTX an TRACE_WAKE */

static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,

char *delim)

{

struct ctx_switch_entry *field;

char comm[TASK_COMM_LEN];

int S, T;

trace_assign_type(field, iter->ent);

T = task_state_char(field->next_state);

S = task_state_char(field->prev_state);

trace_find_cmdline(field->next_pid, comm);

if (!trace_seq_printf(&iter->seq,

" %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",

field->prev_pid,

field->prev_prio,

S, delim,

field->next_cpu,

field->next_pid,

field->next_prio,

T, comm))

return TRACE_TYPE_PARTIAL_LINE;

return TRACE_TYPE_HANDLED;

}

static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,

struct trace_event *event)

{

return trace_ctxwake_print(iter, "==>");