Commit message: tracing: Fix possible double free on failure of allocating trace buffer

Jing Xia and Chunyan Zhang reported that on failing to allocate part of the
tracing buffer, memory is freed, but the pointers that point to them are not
initialized back to NULL, and later paths may try to free the freed memory
again. Jing and Chunyan fixed one of the locations that does this, but
missed a spot.

Link: http://lkml.kernel.org/r/20171226071253.8968-1-chunyan.zhang@spreadtrum.com

Cc: stable@vger.kernel.org
Fixes: 737223fbca3b1 ("tracing: Consolidate buffer allocation code")
Reported-by: Jing Xia <jing.xia@spreadtrum.com>
Reported-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
CVE: CVE-2017-18595
CWE: CWE-415
Vulnerability description: An issue was discovered in the Linux kernel before 4.14.11. A double free may be caused by the function allocate_trace_buffer in the file kernel/trace/trace.c.

Project: linux
File: trace.c

tracing_write_stub(struct file *filp, const char __user *ubuf,
		   size_t count, loff_t *ppos)
{
	return count;
}

Project: linux
File: trace.c

static void *saved_cmdlines_next(struct seq_file *m, void *v, loff_t *pos)
{
	unsigned int *ptr = v;

	if (*pos || m->count)
		ptr++;

	(*pos)++;

	for (; ptr < &savedcmd->map_cmdline_to_pid[savedcmd->cmdline_num];
	     ptr++) {
		if (*ptr == -1 || *ptr == NO_CMDLINE_MAP)
			continue;

		return ptr;
	}

	return NULL;
}

Project: linux
File: trace.c

static void print_func_help_header_irq(struct trace_buffer *buf, struct seq_file *m,
				       unsigned int flags)
{
	bool tgid = flags & TRACE_ITER_RECORD_TGID;
	const char tgid_space[] = "          ";
	const char space[] = "  ";

	seq_printf(m, "#                          %s  _-----=> irqs-off\n",
		   tgid ? tgid_space : space);
	seq_printf(m, "#                          %s / _----=> need-resched\n",
		   tgid ? tgid_space : space);
	seq_printf(m, "#                          %s| / _---=> hardirq/softirq\n",
		   tgid ? tgid_space : space);
	seq_printf(m, "#                          %s|| / _--=> preempt-depth\n",
		   tgid ? tgid_space : space);
	seq_printf(m, "#                          %s||| /     delay\n",
		   tgid ? tgid_space : space);
	seq_printf(m, "#           TASK-PID   CPU#%s||||    TIMESTAMP  FUNCTION\n",
		   tgid ? "   TGID   " : space);
	seq_printf(m, "#              | |       | %s||||       |         |\n",
		   tgid ? "     |    " : space);
}

Project: linux
File: trace.c

static void __ftrace_trace_stack(struct ring_buffer *buffer,
				 unsigned long flags,
				 int skip, int pc, struct pt_regs *regs)
{
	struct trace_event_call *call = &event_kernel_stack;
	struct ring_buffer_event *event;
	struct stack_entry *entry;
	struct stack_trace trace;
	int use_stack;
	int size = FTRACE_STACK_ENTRIES;

	trace.nr_entries	= 0;
	trace.skip		= skip;

	/*
	 * Add two, for this function and the call to save_stack_trace()
	 * If regs is set, then these functions will not be in the way.
	 */
	if (!regs)
		trace.skip += 2;

	/*
	 * Since events can happen in NMIs there's no safe way to
	 * use the per cpu ftrace_stacks. We reserve it and if an interrupt
	 * or NMI comes in, it will just have to use the default
	 * FTRACE_STACK_SIZE.
	 */
	preempt_disable_notrace();

	use_stack = __this_cpu_inc_return(ftrace_stack_reserve);
	/*
	 * We don't need any atomic variables, just a barrier.
	 * If an interrupt comes in, we don't care, because it would
	 * have exited and put the counter back to what we want.
	 * We just need a barrier to keep gcc from moving things
	 * around.
	 */
	barrier();
	if (use_stack == 1) {
		trace.entries		= this_cpu_ptr(ftrace_stack.calls);
		trace.max_entries	= FTRACE_STACK_MAX_ENTRIES;

		if (regs)
			save_stack_trace_regs(regs, &trace);
		else
			save_stack_trace(&trace);

		if (trace.nr_entries > size)
			size = trace.nr_entries;
	} else
		/* From now on, use_stack is a boolean */
		use_stack = 0;

	size *= sizeof(unsigned long);

	event = __trace_buffer_lock_reserve(buffer, TRACE_STACK,
					    sizeof(*entry) + size, flags, pc);
	if (!event)
		goto out;
	entry = ring_buffer_event_data(event);

	memset(&entry->caller, 0, size);

	if (use_stack)
		memcpy(&entry->caller, trace.entries,
		       trace.nr_entries * sizeof(unsigned long));
	else {
		trace.max_entries	= FTRACE_STACK_ENTRIES;
		trace.entries		= entry->caller;
		if (regs)
			save_stack_trace_regs(regs, &trace);
		else
			save_stack_trace(&trace);
	}

	entry->size = trace.nr_entries;

	if (!call_filter_check_discard(call, entry, buffer, event))
		__buffer_unlock_commit(buffer, event);

 out:
	/* Again, don't let gcc optimize things here */
	barrier();
	__this_cpu_dec(ftrace_stack_reserve);
	preempt_enable_notrace();

}

Project: linux
File: trace.c

tracing_saved_cmdlines_size_read(struct file *filp, char __user *ubuf,
				 size_t cnt, loff_t *ppos)
{
	char buf[64];
	int r;

	arch_spin_lock(&trace_cmdline_lock);
	r = scnprintf(buf, sizeof(buf), "%u\n", savedcmd->cmdline_num);
	arch_spin_unlock(&trace_cmdline_lock);

	return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
}

Project: linux
File: trace.c

ftrace_snapshot_free(struct ftrace_probe_ops *ops, struct trace_array *tr,
		     unsigned long ip, void *data)
{
	struct ftrace_func_mapper *mapper = data;

	if (!ip) {
		if (!mapper)
			return;
		free_ftrace_func_mapper(mapper, NULL);
		return;
	}

	ftrace_func_mapper_remove_ip(mapper, ip);
}

Project: linux
File: trace.c

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(ftrace_dump_on_oops);
		break;
	default:
		break;
	}
	return NOTIFY_OK;
}

Project: linux
File: trace.c

add_trace_export(struct trace_export **list, struct trace_export *export)
{
	rcu_assign_pointer(export->next, *list);
	/*
	 * We are entering export into the list but another
	 * CPU might be walking that list. We need to make sure
	 * the export->next pointer is valid before another CPU sees
	 * the export pointer included into the list.
	 */
	rcu_assign_pointer(*list, export);
}

Project: linux
File: trace.c

void tracer_tracing_off(struct trace_array *tr)
{
	if (tr->trace_buffer.buffer)
		ring_buffer_record_off(tr->trace_buffer.buffer);
	/*
	 * This flag is looked at when buffers haven't been allocated
	 * yet, or by some tracers (like irqsoff), that just want to
	 * know if the ring buffer has been disabled, but it can handle
	 * races of where it gets disabled but we still do a record.
	 * As the check is in the fast path of the tracers, it is more
	 * important to be fast than accurate.
	 */
	tr->buffer_disabled = 1;
	/* Make the flag seen by readers */
	smp_wmb();
}

Project: linux
File: trace.c

int trace_pid_show(struct seq_file *m, void *v)
{
	unsigned long pid = (unsigned long)v - 1;

	seq_printf(m, "%lu\n", pid);
	return 0;
}

Project: linux
File: trace.c

static void test_ftrace_alive(struct seq_file *m)
{
	if (!ftrace_is_dead())
		return;
	seq_puts(m, "# WARNING: FUNCTION TRACING IS CORRUPTED\n"
		    "#          MAY BE MISSING FUNCTION EVENTS\n");
}

Project: linux
File: trace.c

trace_ignore_this_task(struct trace_pid_list *filtered_pids, struct task_struct *task)
{
	/*
	 * Return false, because if filtered_pids does not exist,
	 * all pids are good to trace.
	 */
	if (!filtered_pids)
		return false;

	return !trace_find_filtered_pid(filtered_pids, task->pid);
}

Project: linux
File: trace.c

int __trace_puts(unsigned long ip, const char *str, int size)
{
	struct ring_buffer_event *event;
	struct ring_buffer *buffer;
	struct print_entry *entry;
	unsigned long irq_flags;
	int alloc;
	int pc;

	if (!(global_trace.trace_flags & TRACE_ITER_PRINTK))
		return 0;

	pc = preempt_count();

	if (unlikely(tracing_selftest_running || tracing_disabled))
		return 0;

	alloc = sizeof(*entry) + size + 2; /* possible \n added */

	local_save_flags(irq_flags);
	buffer = global_trace.trace_buffer.buffer;
	event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc, 
					    irq_flags, pc);
	if (!event)
		return 0;

	entry = ring_buffer_event_data(event);
	entry->ip = ip;

	memcpy(&entry->buf, str, size);

	/* Add a newline if necessary */
	if (entry->buf[size - 1] != '\n') {
		entry->buf[size] = '\n';
		entry->buf[size + 1] = '\0';
	} else
		entry->buf[size] = '\0';

	__buffer_unlock_commit(buffer, event);
	ftrace_trace_stack(&global_trace, buffer, irq_flags, 4, pc, NULL);

	return size;
}

Project: linux
File: trace.c

static void tracing_spd_release_pipe(struct splice_pipe_desc *spd,
				     unsigned int idx)
{
	__free_page(spd->pages[idx]);
}

Project: linux
File: trace.c

void tracing_record_taskinfo_sched_switch(struct task_struct *prev,
					  struct task_struct *next, int flags)
{
	bool done;

	if (tracing_record_taskinfo_skip(flags))
		return;

	/*
	 * Record as much task information as possible. If some fail, continue
	 * to try to record the others.
	 */
	done  = !(flags & TRACE_RECORD_CMDLINE) || trace_save_cmdline(prev);
	done &= !(flags & TRACE_RECORD_CMDLINE) || trace_save_cmdline(next);
	done &= !(flags & TRACE_RECORD_TGID) || trace_save_tgid(prev);
	done &= !(flags & TRACE_RECORD_TGID) || trace_save_tgid(next);

	/* If recording any information failed, retry again soon. */
	if (!done)
		return;

	__this_cpu_write(trace_taskinfo_save, false);
}

Project: linux
File: trace.c

static void show_snapshot_percpu_help(struct seq_file *m)
{
	seq_puts(m, "# echo 0 > snapshot : Invalid for per_cpu snapshot file.\n");
#ifdef CONFIG_RING_BUFFER_ALLOW_SWAP
	seq_puts(m, "# echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.\n"
		    "#                      Takes a snapshot of the main buffer for this cpu.\n");
#else
	seq_puts(m, "# echo 1 > snapshot : Not supported with this kernel.\n"
		    "#                     Must use main snapshot file to allocate.\n");
#endif
	seq_puts(m, "# echo 2 > snapshot : Clears this cpu's snapshot buffer (but does not allocate)\n"
		    "#                      (Doesn't have to be '2' works with any number that\n"
		    "#                       is not a '0' or '1')\n");
}

Project: linux
File: trace.c

static inline __init int register_snapshot_cmd(void) { return 0; }

Project: linux
File: trace.c

static inline void trace_access_lock_init(void)
{
	int cpu;

	for_each_possible_cpu(cpu)
		mutex_init(&per_cpu(cpu_access_lock, cpu));
}

Project: linux
File: trace.c

static void trace_module_add_evals(struct module *mod)
{
	if (!mod->num_trace_evals)
		return;

	/*
	 * Modules with bad taint do not have events created, do
	 * not bother with enums either.
	 */
	if (trace_module_has_bad_taint(mod))
		return;

	trace_insert_eval_map(mod, mod->trace_evals, mod->num_trace_evals);
}

Project: linux
File: trace.c

static enum print_line_t print_raw_fmt(struct trace_iterator *iter)
{
	struct trace_array *tr = iter->tr;
	struct trace_seq *s = &iter->seq;
	struct trace_entry *entry;
	struct trace_event *event;

	entry = iter->ent;

	if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO)
		trace_seq_printf(s, "%d %d %llu ",
				 entry->pid, iter->cpu, iter->ts);

	if (trace_seq_has_overflowed(s))
		return TRACE_TYPE_PARTIAL_LINE;

	event = ftrace_find_event(entry->type);
	if (event)
		return event->funcs->raw(iter, 0, event);

	trace_seq_printf(s, "%d ?\n", entry->type);

	return trace_handle_return(s);
}

Project: linux
File: trace.c

static int __init set_tracing_thresh(char *str)
{
	unsigned long threshold;
	int ret;

	if (!str)
		return 0;
	ret = kstrtoul(str, 0, &threshold);
	if (ret < 0)
		return 0;
	tracing_thresh = threshold * 1000;
	return 1;
}

Project: linux
File: trace.c

trace_options_core_read(struct file *filp, char __user *ubuf, size_t cnt,
			loff_t *ppos)
{
	void *tr_index = filp->private_data;
	struct trace_array *tr;
	unsigned int index;
	char *buf;

	get_tr_index(tr_index, &tr, &index);

	if (tr->trace_flags & (1 << index))
		buf = "1\n";
	else
		buf = "0\n";

	return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
}

Project: linux
File: trace.c

static void show_snapshot_main_help(struct seq_file *m)
{
	seq_puts(m, "# echo 0 > snapshot : Clears and frees snapshot buffer\n"
		    "# echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.\n"
		    "#                      Takes a snapshot of the main buffer.\n"
		    "# echo 2 > snapshot : Clears snapshot buffer (but does not allocate or free)\n"
		    "#                      (Doesn't have to be '2' works with any number that\n"
		    "#                       is not a '0' or '1')\n");
}

Project: linux
File: trace.c

void tracing_snapshot_alloc(void)
{
	/* Give warning */
	tracing_snapshot();
}

Project: linux
File: trace.c

__tracing_open(struct inode *inode, struct file *file, bool snapshot)
{
	struct trace_array *tr = inode->i_private;
	struct trace_iterator *iter;
	int cpu;

	if (tracing_disabled)
		return ERR_PTR(-ENODEV);

	iter = __seq_open_private(file, &tracer_seq_ops, sizeof(*iter));
	if (!iter)
		return ERR_PTR(-ENOMEM);

	iter->buffer_iter = kcalloc(nr_cpu_ids, sizeof(*iter->buffer_iter),
				    GFP_KERNEL);
	if (!iter->buffer_iter)
		goto release;

	/*
	 * We make a copy of the current tracer to avoid concurrent
	 * changes on it while we are reading.
	 */
	mutex_lock(&trace_types_lock);
	iter->trace = kzalloc(sizeof(*iter->trace), GFP_KERNEL);
	if (!iter->trace)
		goto fail;

	*iter->trace = *tr->current_trace;

	if (!zalloc_cpumask_var(&iter->started, GFP_KERNEL))
		goto fail;

	iter->tr = tr;

#ifdef CONFIG_TRACER_MAX_TRACE
	/* Currently only the top directory has a snapshot */
	if (tr->current_trace->print_max || snapshot)
		iter->trace_buffer = &tr->max_buffer;
	else
#endif
		iter->trace_buffer = &tr->trace_buffer;
	iter->snapshot = snapshot;
	iter->pos = -1;
	iter->cpu_file = tracing_get_cpu(inode);
	mutex_init(&iter->mutex);

	/* 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->trace_buffer->buffer))
		iter->iter_flags |= TRACE_FILE_ANNOTATE;

	/* Output in nanoseconds only if we are using a clock in nanoseconds. */
	if (trace_clocks[tr->clock_id].in_ns)
		iter->iter_flags |= TRACE_FILE_TIME_IN_NS;

	/* stop the trace while dumping if we are not opening "snapshot" */
	if (!iter->snapshot)
		tracing_stop_tr(tr);

	if (iter->cpu_file == RING_BUFFER_ALL_CPUS) {
		for_each_tracing_cpu(cpu) {
			iter->buffer_iter[cpu] =
				ring_buffer_read_prepare(iter->trace_buffer->buffer, cpu);
		}
		ring_buffer_read_prepare_sync();
		for_each_tracing_cpu(cpu) {
			ring_buffer_read_start(iter->buffer_iter[cpu]);
			tracing_iter_reset(iter, cpu);
		}
	} else {
		cpu = iter->cpu_file;
		iter->buffer_iter[cpu] =
			ring_buffer_read_prepare(iter->trace_buffer->buffer, cpu);
		ring_buffer_read_prepare_sync();
		ring_buffer_read_start(iter->buffer_iter[cpu]);
		tracing_iter_reset(iter, cpu);
	}

	mutex_unlock(&trace_types_lock);

	return iter;

 fail:
	mutex_unlock(&trace_types_lock);
	kfree(iter->trace);
	kfree(iter->buffer_iter);
release:
	seq_release_private(inode, file);
	return ERR_PTR(-ENOMEM);
}

Project: linux
File: trace.c

int trace_array_printk_buf(struct ring_buffer *buffer,
			   unsigned long ip, const char *fmt, ...)
{
	int ret;
	va_list ap;

	if (!(global_trace.trace_flags & TRACE_ITER_PRINTK))
		return 0;

	va_start(ap, fmt);
	ret = __trace_array_vprintk(buffer, ip, fmt, ap);
	va_end(ap);
	return ret;
}

Project: linux
File: trace.c

static int tracing_saved_cmdlines_open(struct inode *inode, struct file *filp)
{
	if (tracing_disabled)
		return -ENODEV;

	return seq_open(filp, &tracing_saved_cmdlines_seq_ops);
}

Project: linux
File: trace.c

static void *eval_map_next(struct seq_file *m, void *v, loff_t *pos)
{
	union trace_eval_map_item *ptr = v;

	/*
	 * Paranoid! If ptr points to end, we don't want to increment past it.
	 * This really should never happen.
	 */
	ptr = update_eval_map(ptr);
	if (WARN_ON_ONCE(!ptr))
		return NULL;

	ptr++;

	(*pos)++;

	ptr = update_eval_map(ptr);

	return ptr;
}

Project: linux
File: trace.c

tracing_thresh_write(struct file *filp, const char __user *ubuf,
		     size_t cnt, loff_t *ppos)
{
	struct trace_array *tr = filp->private_data;
	int ret;

	mutex_lock(&trace_types_lock);
	ret = tracing_nsecs_write(&tracing_thresh, ubuf, cnt, ppos);
	if (ret < 0)
		goto out;

	if (tr->current_trace->update_thresh) {
		ret = tr->current_trace->update_thresh(tr);
		if (ret < 0)
			goto out;
	}

	ret = cnt;
out:
	mutex_unlock(&trace_types_lock);

	return ret;
}

Project: linux
File: trace.c

void trace_dump_stack(int skip)
{
	unsigned long flags;

	if (tracing_disabled || tracing_selftest_running)
		return;

	local_save_flags(flags);

	/*
	 * Skip 3 more, seems to get us at the caller of
	 * this function.
	 */
	skip += 3;
	__ftrace_trace_stack(global_trace.trace_buffer.buffer,
			     flags, skip, preempt_count(), NULL);
}

Project: linux
File: trace.c

static struct dentry *tracing_get_dentry(struct trace_array *tr)
{
	if (WARN_ON(!tr->dir))
		return ERR_PTR(-ENODEV);

	/* Top directory uses NULL as the parent */
	if (tr->flags & TRACE_ARRAY_FL_GLOBAL)
		return NULL;

	/* All sub buffers have a descriptor */
	return tr->dir;
}

Project: linux
File: trace.c

static void print_func_help_header(struct trace_buffer *buf, struct seq_file *m,
				   unsigned int flags)
{
	bool tgid = flags & TRACE_ITER_RECORD_TGID;

	print_event_info(buf, m);

	seq_printf(m, "#           TASK-PID   CPU#   %s  TIMESTAMP  FUNCTION\n", tgid ? "TGID     " : "");
	seq_printf(m, "#              | |       |    %s     |         |\n",	 tgid ? "  |      " : "");
}

Project: linux
File: trace.c

int trace_empty(struct trace_iterator *iter)
{
	struct ring_buffer_iter *buf_iter;
	int cpu;

	/* If we are looking at one CPU buffer, only check that one */
	if (iter->cpu_file != RING_BUFFER_ALL_CPUS) {
		cpu = iter->cpu_file;
		buf_iter = trace_buffer_iter(iter, cpu);
		if (buf_iter) {
			if (!ring_buffer_iter_empty(buf_iter))
				return 0;
		} else {
			if (!ring_buffer_empty_cpu(iter->trace_buffer->buffer, cpu))
				return 0;
		}
		return 1;
	}

	for_each_tracing_cpu(cpu) {
		buf_iter = trace_buffer_iter(iter, cpu);
		if (buf_iter) {
			if (!ring_buffer_iter_empty(buf_iter))
				return 0;
		} else {
			if (!ring_buffer_empty_cpu(iter->trace_buffer->buffer, cpu))
				return 0;
		}
	}

	return 1;
}

Project: linux
File: trace.c

void tracer_tracing_on(struct trace_array *tr)
{
	if (tr->trace_buffer.buffer)
		ring_buffer_record_on(tr->trace_buffer.buffer);
	/*
	 * This flag is looked at when buffers haven't been allocated
	 * yet, or by some tracers (like irqsoff), that just want to
	 * know if the ring buffer has been disabled, but it can handle
	 * races of where it gets disabled but we still do a record.
	 * As the check is in the fast path of the tracers, it is more
	 * important to be fast than accurate.
	 */
	tr->buffer_disabled = 0;
	/* Make the flag seen by readers */
	smp_wmb();
}

Project: linux
File: trace.c

update_eval_map(union trace_eval_map_item *ptr)
{
	if (!ptr->map.eval_string) {
		if (ptr->tail.next) {
			ptr = ptr->tail.next;
			/* Set ptr to the next real item (skip head) */
			ptr++;
		} else
			return NULL;
	}
	return ptr;
}

Project: linux
File: trace.c

static void trace_create_eval_file(struct dentry *d_tracer)
{
	trace_create_file("eval_map", 0444, d_tracer,
			  NULL, &tracing_eval_map_fops);
}

Project: linux
File: trace.c

void *trace_find_next_entry_inc(struct trace_iterator *iter)
{
	iter->ent = __find_next_entry(iter, &iter->cpu,
				      &iter->lost_events, &iter->ts);

	if (iter->ent)
		trace_iterator_increment(iter);

	return iter->ent ? iter : NULL;
}

Project: linux
File: trace.c

enum print_line_t print_trace_line(struct trace_iterator *iter)
{
	struct trace_array *tr = iter->tr;
	unsigned long trace_flags = tr->trace_flags;
	enum print_line_t ret;

	if (iter->lost_events) {
		trace_seq_printf(&iter->seq, "CPU:%d [LOST %lu EVENTS]\n",
				 iter->cpu, iter->lost_events);
		if (trace_seq_has_overflowed(&iter->seq))
			return TRACE_TYPE_PARTIAL_LINE;
	}

	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_BPUTS &&
			trace_flags & TRACE_ITER_PRINTK &&
			trace_flags & TRACE_ITER_PRINTK_MSGONLY)
		return trace_print_bputs_msg_only(iter);

	if (iter->ent->type == TRACE_BPRINT &&
			trace_flags & TRACE_ITER_PRINTK &&
			trace_flags & TRACE_ITER_PRINTK_MSGONLY)
		return trace_print_bprintk_msg_only(iter);

	if (iter->ent->type == TRACE_PRINT &&
			trace_flags & TRACE_ITER_PRINTK &&
			trace_flags & TRACE_ITER_PRINTK_MSGONLY)
		return trace_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);

	return print_trace_fmt(iter);
}

Project: linux
File: trace.c

static int tracing_release_generic_tr(struct inode *inode, struct file *file)
{
	struct trace_array *tr = inode->i_private;

	trace_array_put(tr);
	return 0;
}

Project: linux
File: trace.c

static void tracing_start_tr(struct trace_array *tr)
{
	struct ring_buffer *buffer;
	unsigned long flags;

	if (tracing_disabled)
		return;

	/* If global, we need to also start the max tracer */
	if (tr->flags & TRACE_ARRAY_FL_GLOBAL)
		return tracing_start();

	raw_spin_lock_irqsave(&tr->start_lock, flags);

	if (--tr->stop_count) {
		if (tr->stop_count < 0) {
			/* Someone screwed up their debugging */
			WARN_ON_ONCE(1);
			tr->stop_count = 0;
		}
		goto out;
	}

	buffer = tr->trace_buffer.buffer;
	if (buffer)
		ring_buffer_record_enable(buffer);

 out:
	raw_spin_unlock_irqrestore(&tr->start_lock, flags);
}

Project: linux
File: trace.c

get_total_entries(struct trace_buffer *buf,
		  unsigned long *total, unsigned long *entries)
{
	unsigned long count;
	int cpu;

	*total = 0;
	*entries = 0;

	for_each_tracing_cpu(cpu) {
		count = ring_buffer_entries_cpu(buf->buffer, cpu);
		/*
		 * If this buffer has skipped entries, then we hold all
		 * entries for the trace and we need to ignore the
		 * ones before the time stamp.
		 */
		if (per_cpu_ptr(buf->data, cpu)->skipped_entries) {
			count -= per_cpu_ptr(buf->data, cpu)->skipped_entries;
			/* total is the same as the entries */
			*total += count;
		} else
			*total += count +
				ring_buffer_overrun_cpu(buf->buffer, cpu);
		*entries += count;
	}
}

Project: linux
File: trace.c

static void enable_trace_buffered_event(void *data)
{
	/* Probably not needed, but do it anyway */
	smp_rmb();
	this_cpu_dec(trace_buffered_event_cnt);
}

Project: linux
File: trace.c

rm_trace_export(struct trace_export **list, struct trace_export *export)
{
	struct trace_export **p;

	for (p = list; *p != NULL; p = &(*p)->next)
		if (*p == export)
			break;

	if (*p != export)
		return -1;

	rcu_assign_pointer(*p, (*p)->next);

	return 0;
}

Project: linux
File: trace.c

static int eval_map_show(struct seq_file *m, void *v)
{
	union trace_eval_map_item *ptr = v;

	seq_printf(m, "%s %ld (%s)\n",
		   ptr->map.eval_string, ptr->map.eval_value,
		   ptr->map.system);

	return 0;
}

Project: linux
File: trace.c

dummy_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
{
	return 0;
}

Project: linux
File: trace.c

tracing_cpumask_write(struct file *filp, const char __user *ubuf,
		      size_t count, loff_t *ppos)
{
	struct trace_array *tr = file_inode(filp)->i_private;
	cpumask_var_t tracing_cpumask_new;
	int err, cpu;

	if (!alloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL))
		return -ENOMEM;

	err = cpumask_parse_user(ubuf, count, tracing_cpumask_new);
	if (err)
		goto err_unlock;

	local_irq_disable();
	arch_spin_lock(&tr->max_lock);
	for_each_tracing_cpu(cpu) {
		/*
		 * Increase/decrease the disabled counter if we are
		 * about to flip a bit in the cpumask:
		 */
		if (cpumask_test_cpu(cpu, tr->tracing_cpumask) &&
				!cpumask_test_cpu(cpu, tracing_cpumask_new)) {
			atomic_inc(&per_cpu_ptr(tr->trace_buffer.data, cpu)->disabled);
			ring_buffer_record_disable_cpu(tr->trace_buffer.buffer, cpu);
		}
		if (!cpumask_test_cpu(cpu, tr->tracing_cpumask) &&
				cpumask_test_cpu(cpu, tracing_cpumask_new)) {
			atomic_dec(&per_cpu_ptr(tr->trace_buffer.data, cpu)->disabled);
			ring_buffer_record_enable_cpu(tr->trace_buffer.buffer, cpu);
		}
	}
	arch_spin_unlock(&tr->max_lock);
	local_irq_enable();

	cpumask_copy(tr->tracing_cpumask, tracing_cpumask_new);
	free_cpumask_var(tracing_cpumask_new);

	return count;

err_unlock:
	free_cpumask_var(tracing_cpumask_new);

	return err;
}

Project: linux
File: trace.c

tracing_free_buffer_release(struct inode *inode, struct file *filp)
{
	struct trace_array *tr = inode->i_private;

	/* disable tracing ? */
	if (tr->trace_flags & TRACE_ITER_STOP_ON_FREE)
		tracer_tracing_off(tr);
	/* resize the ring buffer to 0 */
	tracing_resize_ring_buffer(tr, 0, RING_BUFFER_ALL_CPUS);

	trace_array_put(tr);

	return 0;
}

Project: linux
File: trace.c

void trace_array_put(struct trace_array *this_tr)
{
	mutex_lock(&trace_types_lock);
	__trace_array_put(this_tr);
	mutex_unlock(&trace_types_lock);
}

Project: linux
File: trace.c

u64 ftrace_now(int cpu)
{
	return buffer_ftrace_now(&global_trace.trace_buffer, cpu);
}

Project: linux
File: trace.c

void trace_latency_header(struct seq_file *m)
{
	struct trace_iterator *iter = m->private;
	struct trace_array *tr = iter->tr;

	/* print nothing if the buffers are empty */
	if (trace_empty(iter))
		return;

	if (iter->iter_flags & TRACE_FILE_LAT_FMT)
		print_trace_header(m, iter);

	if (!(tr->trace_flags & TRACE_ITER_VERBOSE))
		print_lat_help_header(m);
}

Project: linux
File: trace.c

int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
{
	return trace_array_vprintk(&global_trace, ip, fmt, args);
}

Project: linux
File: trace.c

static int tracing_open_generic_tr(struct inode *inode, struct file *filp)
{
	struct trace_array *tr = inode->i_private;

	if (tracing_disabled)
		return -ENODEV;

	if (trace_array_get(tr) < 0)
		return -ENODEV;

	filp->private_data = inode->i_private;

	return 0;
}

Project: linux
File: trace.c

rb_simple_write(struct file *filp, const char __user *ubuf,
		size_t cnt, loff_t *ppos)
{
	struct trace_array *tr = filp->private_data;
	struct ring_buffer *buffer = tr->trace_buffer.buffer;
	unsigned long val;
	int ret;

	ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
	if (ret)
		return ret;

	if (buffer) {
		mutex_lock(&trace_types_lock);
		if (val) {
			tracer_tracing_on(tr);
			if (tr->current_trace->start)
				tr->current_trace->start(tr);
		} else {
			tracer_tracing_off(tr);
			if (tr->current_trace->stop)
				tr->current_trace->stop(tr);
		}
		mutex_unlock(&trace_types_lock);
	}

	(*ppos)++;

	return cnt;
}

Project: linux
File: trace.c

static void get_tr_index(void *data, struct trace_array **ptr,
			 unsigned int *pindex)
{
	*pindex = *(unsigned char *)data;

	*ptr = container_of(data - *pindex, struct trace_array,
			    trace_flags_index);
}

Project: linux
File: trace.c

static void print_event_info(struct trace_buffer *buf, struct seq_file *m)
{
	unsigned long total;
	unsigned long entries;

	get_total_entries(buf, &total, &entries);
	seq_printf(m, "# entries-in-buffer/entries-written: %lu/%lu   #P:%d\n",
		   entries, total, num_online_cpus());
	seq_puts(m, "#\n");
}

Project: linux
File: trace.c

void tracing_stop(void)
{
	struct ring_buffer *buffer;
	unsigned long flags;

	raw_spin_lock_irqsave(&global_trace.start_lock, flags);
	if (global_trace.stop_count++)
		goto out;

	/* Prevent the buffers from switching */
	arch_spin_lock(&global_trace.max_lock);

	buffer = global_trace.trace_buffer.buffer;
	if (buffer)
		ring_buffer_record_disable(buffer);

#ifdef CONFIG_TRACER_MAX_TRACE
	buffer = global_trace.max_buffer.buffer;
	if (buffer)
		ring_buffer_record_disable(buffer);
#endif

	arch_spin_unlock(&global_trace.max_lock);

 out:
	raw_spin_unlock_irqrestore(&global_trace.start_lock, flags);
}

Project: linux
File: trace.c

void trace_buffered_event_disable(void)
{
	int cpu;

	WARN_ON_ONCE(!mutex_is_locked(&event_mutex));

	if (WARN_ON_ONCE(!trace_buffered_event_ref))
		return;

	if (--trace_buffered_event_ref)
		return;

	preempt_disable();
	/* For each CPU, set the buffer as used. */
	smp_call_function_many(tracing_buffer_mask,
			       disable_trace_buffered_event, NULL, 1);
	preempt_enable();

	/* Wait for all current users to finish */
	synchronize_sched();

	for_each_tracing_cpu(cpu) {
		free_page((unsigned long)per_cpu(trace_buffered_event, cpu));
		per_cpu(trace_buffered_event, cpu) = NULL;
	}
	/*
	 * Make sure trace_buffered_event is NULL before clearing
	 * trace_buffered_event_cnt.
	 */
	smp_wmb();

	preempt_disable();
	/* Do the work on each cpu */
	smp_call_function_many(tracing_buffer_mask,
			       enable_trace_buffered_event, NULL, 1);
	preempt_enable();
}

Project: linux
File: trace.c

int trace_pid_write(struct trace_pid_list *filtered_pids,
		    struct trace_pid_list **new_pid_list,
		    const char __user *ubuf, size_t cnt)
{
	struct trace_pid_list *pid_list;
	struct trace_parser parser;
	unsigned long val;
	int nr_pids = 0;
	ssize_t read = 0;
	ssize_t ret = 0;
	loff_t pos;
	pid_t pid;

	if (trace_parser_get_init(&parser, PID_BUF_SIZE + 1))
		return -ENOMEM;

	/*
	 * Always recreate a new array. The write is an all or nothing
	 * operation. Always create a new array when adding new pids by
	 * the user. If the operation fails, then the current list is
	 * not modified.
	 */
	pid_list = kmalloc(sizeof(*pid_list), GFP_KERNEL);
	if (!pid_list)
		return -ENOMEM;

	pid_list->pid_max = READ_ONCE(pid_max);

	/* Only truncating will shrink pid_max */
	if (filtered_pids && filtered_pids->pid_max > pid_list->pid_max)
		pid_list->pid_max = filtered_pids->pid_max;

	pid_list->pids = vzalloc((pid_list->pid_max + 7) >> 3);
	if (!pid_list->pids) {
		kfree(pid_list);
		return -ENOMEM;
	}

	if (filtered_pids) {
		/* copy the current bits to the new max */
		for_each_set_bit(pid, filtered_pids->pids,
				 filtered_pids->pid_max) {
			set_bit(pid, pid_list->pids);
			nr_pids++;
		}
	}

	while (cnt > 0) {

		pos = 0;

		ret = trace_get_user(&parser, ubuf, cnt, &pos);
		if (ret < 0 || !trace_parser_loaded(&parser))
			break;

		read += ret;
		ubuf += ret;
		cnt -= ret;

		parser.buffer[parser.idx] = 0;

		ret = -EINVAL;
		if (kstrtoul(parser.buffer, 0, &val))
			break;
		if (val >= pid_list->pid_max)
			break;

		pid = (pid_t)val;

		set_bit(pid, pid_list->pids);
		nr_pids++;

		trace_parser_clear(&parser);
		ret = 0;
	}
	trace_parser_put(&parser);

	if (ret < 0) {
		trace_free_pid_list(pid_list);
		return ret;
	}

	if (!nr_pids) {
		/* Cleared the list of pids */
		trace_free_pid_list(pid_list);
		read = ret;
		pid_list = NULL;
	}

	*new_pid_list = pid_list;

	return read;
}

Project: linux
File: trace.c

static int instance_rmdir(const char *name)
{
	struct trace_array *tr;
	int found = 0;
	int ret;
	int i;

	mutex_lock(&event_mutex);
	mutex_lock(&trace_types_lock);

	ret = -ENODEV;
	list_for_each_entry(tr, &ftrace_trace_arrays, list) {
		if (tr->name && strcmp(tr->name, name) == 0) {
			found = 1;
			break;
		}
	}
	if (!found)
		goto out_unlock;

	ret = -EBUSY;
	if (tr->ref || (tr->current_trace && tr->current_trace->ref))
		goto out_unlock;

	list_del(&tr->list);

	/* Disable all the flags that were enabled coming in */
	for (i = 0; i < TRACE_FLAGS_MAX_SIZE; i++) {
		if ((1 << i) & ZEROED_TRACE_FLAGS)
			set_tracer_flag(tr, 1 << i, 0);
	}

	tracing_set_nop(tr);
	clear_ftrace_function_probes(tr);
	event_trace_del_tracer(tr);
	ftrace_clear_pids(tr);
	ftrace_destroy_function_files(tr);
	tracefs_remove_recursive(tr->dir);
	free_trace_buffers(tr);

	for (i = 0; i < tr->nr_topts; i++) {
		kfree(tr->topts[i].topts);
	}
	kfree(tr->topts);

	free_cpumask_var(tr->tracing_cpumask);
	kfree(tr->name);
	kfree(tr);

	ret = 0;

 out_unlock:
	mutex_unlock(&trace_types_lock);
	mutex_unlock(&event_mutex);

	return ret;
}

Project: linux
File: trace.c

int tracing_update_buffers(void)
{
	int ret = 0;

	mutex_lock(&trace_types_lock);
	if (!ring_buffer_expanded)
		ret = __tracing_resize_ring_buffer(&global_trace, trace_buf_size,
						RING_BUFFER_ALL_CPUS);
	mutex_unlock(&trace_types_lock);

	return ret;
}

Project: linux
File: trace.c

static void __update_tracer_options(struct trace_array *tr)
{
	struct tracer *t;

	for (t = trace_types; t; t = t->next)
		add_tracer_options(tr, t);
}

Project: linux
File: trace.c

void trace_buffered_event_enable(void)
{
	struct ring_buffer_event *event;
	struct page *page;
	int cpu;

	WARN_ON_ONCE(!mutex_is_locked(&event_mutex));

	if (trace_buffered_event_ref++)
		return;

	for_each_tracing_cpu(cpu) {
		page = alloc_pages_node(cpu_to_node(cpu),
					GFP_KERNEL | __GFP_NORETRY, 0);
		if (!page)
			goto failed;

		event = page_address(page);
		memset(event, 0, sizeof(*event));

		per_cpu(trace_buffered_event, cpu) = event;

		preempt_disable();
		if (cpu == smp_processor_id() &&
		    this_cpu_read(trace_buffered_event) !=
		    per_cpu(trace_buffered_event, cpu))
			WARN_ON_ONCE(1);
		preempt_enable();
	}

	return;
 failed:
	trace_buffered_event_disable();
}

Project: linux
File: trace.c

void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos)
{
	unsigned long pid = (unsigned long)v;

	(*pos)++;

	/* pid already is +1 of the actual prevous bit */
	pid = find_next_bit(pid_list->pids, pid_list->pid_max, pid);

	/* Return pid + 1 to allow zero to be represented */
	if (pid < pid_list->pid_max)
		return (void *)(pid + 1);

	return NULL;
}

Project: linux
File: trace.c

static void *t_start(struct seq_file *m, loff_t *pos)
{
	struct trace_array *tr = m->private;
	struct tracer *t;
	loff_t l = 0;

	mutex_lock(&trace_types_lock);

	t = get_tracer_for_array(tr, trace_types);
	for (; t && l < *pos; t = t_next(m, t, &l))
			;

	return t;
}

Project: linux
File: trace.c

static void trace_module_remove_evals(struct module *mod)
{
	union trace_eval_map_item *map;
	union trace_eval_map_item **last = &trace_eval_maps;

	if (!mod->num_trace_evals)
		return;

	mutex_lock(&trace_eval_mutex);

	map = trace_eval_maps;

	while (map) {
		if (map->head.mod == mod)
			break;
		map = trace_eval_jmp_to_tail(map);
		last = &map->tail.next;
		map = map->tail.next;
	}
	if (!map)
		goto out;

	*last = trace_eval_jmp_to_tail(map)->tail.next;
	kfree(map);
 out:
	mutex_unlock(&trace_eval_mutex);
}

Project: linux
File: trace.c

static int trace_save_cmdline(struct task_struct *tsk)
{
	unsigned pid, idx;

	/* treat recording of idle task as a success */
	if (!tsk->pid)
		return 1;

	if (unlikely(tsk->pid > PID_MAX_DEFAULT))
		return 0;

	/*
	 * 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 (!arch_spin_trylock(&trace_cmdline_lock))
		return 0;

	idx = savedcmd->map_pid_to_cmdline[tsk->pid];
	if (idx == NO_CMDLINE_MAP) {
		idx = (savedcmd->cmdline_idx + 1) % savedcmd->cmdline_num;

		/*
		 * Check whether the cmdline buffer at idx has a pid
		 * mapped. We are going to overwrite that entry so we
		 * need to clear the map_pid_to_cmdline. Otherwise we
		 * would read the new comm for the old pid.
		 */
		pid = savedcmd->map_cmdline_to_pid[idx];
		if (pid != NO_CMDLINE_MAP)
			savedcmd->map_pid_to_cmdline[pid] = NO_CMDLINE_MAP;

		savedcmd->map_cmdline_to_pid[idx] = tsk->pid;
		savedcmd->map_pid_to_cmdline[tsk->pid] = idx;

		savedcmd->cmdline_idx = idx;
	}

	set_cmdline(idx, tsk->comm);

	arch_spin_unlock(&trace_cmdline_lock);

	return 1;
}

Project: linux
File: trace.c

ftrace_snapshot(unsigned long ip, unsigned long parent_ip,
		struct trace_array *tr, struct ftrace_probe_ops *ops,
		void *data)
{
	tracing_snapshot_instance(tr);
}

Project: linux
File: trace.c

static __init void create_trace_instances(struct dentry *d_tracer)
{
	trace_instance_dir = tracefs_create_instance_dir("instances", d_tracer,
							 instance_mkdir,
							 instance_rmdir);
	if (WARN_ON(!trace_instance_dir))
		return;
}

Project: linux
File: trace.c

static void set_buffer_entries(struct trace_buffer *buf, unsigned long val)
{
	int cpu;

	for_each_tracing_cpu(cpu)
		per_cpu_ptr(buf->data, cpu)->entries = val;
}

Project: linux
File: trace.c

static void __trace_find_cmdline(int pid, char comm[])
{
	unsigned map;

	if (!pid) {
		strcpy(comm, "<idle>");
		return;
	}

	if (WARN_ON_ONCE(pid < 0)) {
		strcpy(comm, "<XXX>");
		return;
	}

	if (pid > PID_MAX_DEFAULT) {
		strcpy(comm, "<...>");
		return;
	}

	map = savedcmd->map_pid_to_cmdline[pid];
	if (map != NO_CMDLINE_MAP)
		strlcpy(comm, get_saved_cmdlines(map), TASK_COMM_LEN);
	else
		strcpy(comm, "<...>");
}

Project: linux
File: trace.c

static inline void trace_access_lock(int cpu)
{
	(void)cpu;
	mutex_lock(&access_lock);
}

Project: linux
File: trace.c

static struct dentry *trace_options_init_dentry(struct trace_array *tr)
{
	struct dentry *d_tracer;

	if (tr->options)
		return tr->options;

	d_tracer = tracing_get_dentry(tr);
	if (IS_ERR(d_tracer))
		return NULL;

	tr->options = tracefs_create_dir("options", d_tracer);
	if (!tr->options) {
		pr_warn("Could not create tracefs directory 'options'\n");
		return NULL;
	}

	return tr->options;
}

Project: linux
File: trace.c

static void __trace_userstack(struct trace_array *tr, unsigned long flags)
{
	ftrace_trace_userstack(tr, flags, preempt_count());
}

Project: linux
File: trace.c

static int tracing_open(struct inode *inode, struct file *file)
{
	struct trace_array *tr = inode->i_private;
	struct trace_iterator *iter;
	int ret = 0;

	if (trace_array_get(tr) < 0)
		return -ENODEV;

	/* If this file was open for write, then erase contents */
	if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
		int cpu = tracing_get_cpu(inode);
		struct trace_buffer *trace_buf = &tr->trace_buffer;

#ifdef CONFIG_TRACER_MAX_TRACE
		if (tr->current_trace->print_max)
			trace_buf = &tr->max_buffer;
#endif

		if (cpu == RING_BUFFER_ALL_CPUS)
			tracing_reset_online_cpus(trace_buf);
		else
			tracing_reset(trace_buf, cpu);
	}

	if (file->f_mode & FMODE_READ) {
		iter = __tracing_open(inode, file, false);
		if (IS_ERR(iter))
			ret = PTR_ERR(iter);
		else if (tr->trace_flags & TRACE_ITER_LATENCY_FMT)
			iter->iter_flags |= TRACE_FILE_LAT_FMT;
	}

	if (ret < 0)
		trace_array_put(tr);

	return ret;
}

Project: linux
File: trace.c

static inline void set_cmdline(int idx, const char *cmdline)
{
	memcpy(get_saved_cmdlines(idx), cmdline, TASK_COMM_LEN);
}

Project: linux
File: trace.c

ftrace_trace_snapshot_callback(struct trace_array *tr, struct ftrace_hash *hash,
			       char *glob, char *cmd, char *param, int enable)
{
	struct ftrace_probe_ops *ops;
	void *count = (void *)-1;
	char *number;
	int ret;

	if (!tr)
		return -ENODEV;

	/* hash funcs only work with set_ftrace_filter */
	if (!enable)
		return -EINVAL;

	ops = param ? &snapshot_count_probe_ops :  &snapshot_probe_ops;

	if (glob[0] == '!')
		return unregister_ftrace_function_probe_func(glob+1, tr, ops);

	if (!param)
		goto out_reg;

	number = strsep(&param, ":");

	if (!strlen(number))
		goto out_reg;

	/*
	 * We use the callback data field (which is a pointer)
	 * as our counter.
	 */
	ret = kstrtoul(number, 0, (unsigned long *)&count);
	if (ret)
		return ret;

 out_reg:
	ret = alloc_snapshot(tr);
	if (ret < 0)
		goto out;

	ret = register_ftrace_function_probe(glob, tr, ops, count);

 out:
	return ret < 0 ? ret : 0;
}

Project: linux
File: trace.c

static void *saved_tgids_next(struct seq_file *m, void *v, loff_t *pos)
{
	int *ptr = v;

	if (*pos || m->count)
		ptr++;

	(*pos)++;

	for (; ptr <= &tgid_map[PID_MAX_DEFAULT]; ptr++) {
		if (trace_find_tgid(*ptr))
			return ptr;
	}

	return NULL;
}

Project: linux
File: trace.c

int trace_array_vprintk(struct trace_array *tr,
			unsigned long ip, const char *fmt, va_list args)
{
	return __trace_array_vprintk(tr->trace_buffer.buffer, ip, fmt, args);
}

Project: linux
File: trace.c

tracing_buffers_poll(struct file *filp, poll_table *poll_table)
{
	struct ftrace_buffer_info *info = filp->private_data;
	struct trace_iterator *iter = &info->iter;

	return trace_poll(iter, filp, poll_table);
}

Project: linux
File: trace.c

static inline void trace_access_lock(int cpu)
{
	if (cpu == RING_BUFFER_ALL_CPUS) {
		/* gain it for accessing the whole ring buffer. */
		down_write(&all_cpu_access_lock);
	} else {
		/* gain it for accessing a cpu ring buffer. */

		/* Firstly block other trace_access_lock(RING_BUFFER_ALL_CPUS). */
		down_read(&all_cpu_access_lock);

		/* Secondly block other access to this @cpu ring buffer. */
		mutex_lock(&per_cpu(cpu_access_lock, cpu));
	}
}

Project: linux
File: trace.c

static int saved_tgids_show(struct seq_file *m, void *v)
{
	int pid = (int *)v - tgid_map;

	seq_printf(m, "%d %d\n", pid, trace_find_tgid(pid));
	return 0;
}

Project: linux
File: trace.c

__init static int tracer_alloc_buffers(void)
{
	int ring_buf_size;
	int ret = -ENOMEM;

	/*
	 * Make sure we don't accidently add more trace options
	 * than we have bits for.
	 */
	BUILD_BUG_ON(TRACE_ITER_LAST_BIT > TRACE_FLAGS_MAX_SIZE);

	if (!alloc_cpumask_var(&tracing_buffer_mask, GFP_KERNEL))
		goto out;

	if (!alloc_cpumask_var(&global_trace.tracing_cpumask, GFP_KERNEL))
		goto out_free_buffer_mask;

	/* Only allocate trace_printk buffers if a trace_printk exists */
	if (__stop___trace_bprintk_fmt != __start___trace_bprintk_fmt)
		/* Must be called before global_trace.buffer is allocated */
		trace_printk_init_buffers();

	/* To save memory, keep the ring buffer size to its minimum */
	if (ring_buffer_expanded)
		ring_buf_size = trace_buf_size;
	else
		ring_buf_size = 1;

	cpumask_copy(tracing_buffer_mask, cpu_possible_mask);
	cpumask_copy(global_trace.tracing_cpumask, cpu_all_mask);

	raw_spin_lock_init(&global_trace.start_lock);

	/*
	 * The prepare callbacks allocates some memory for the ring buffer. We
	 * don't free the buffer if the if the CPU goes down. If we were to free
	 * the buffer, then the user would lose any trace that was in the
	 * buffer. The memory will be removed once the "instance" is removed.
	 */
	ret = cpuhp_setup_state_multi(CPUHP_TRACE_RB_PREPARE,
				      "trace/RB:preapre", trace_rb_cpu_prepare,
				      NULL);
	if (ret < 0)
		goto out_free_cpumask;
	/* Used for event triggers */
	ret = -ENOMEM;
	temp_buffer = ring_buffer_alloc(PAGE_SIZE, RB_FL_OVERWRITE);
	if (!temp_buffer)
		goto out_rm_hp_state;

	if (trace_create_savedcmd() < 0)
		goto out_free_temp_buffer;

	/* TODO: make the number of buffers hot pluggable with CPUS */
	if (allocate_trace_buffers(&global_trace, ring_buf_size) < 0) {
		printk(KERN_ERR "tracer: failed to allocate ring buffer!\n");
		WARN_ON(1);
		goto out_free_savedcmd;
	}

	if (global_trace.buffer_disabled)
		tracing_off();

	if (trace_boot_clock) {
		ret = tracing_set_clock(&global_trace, trace_boot_clock);
		if (ret < 0)
			pr_warn("Trace clock %s not defined, going back to default\n",
				trace_boot_clock);
	}

	/*
	 * register_tracer() might reference current_trace, so it
	 * needs to be set before we register anything. This is
	 * just a bootstrap of current_trace anyway.
	 */
	global_trace.current_trace = &nop_trace;

	global_trace.max_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;

	ftrace_init_global_array_ops(&global_trace);

	init_trace_flags_index(&global_trace);

	register_tracer(&nop_trace);

	/* Function tracing may start here (via kernel command line) */
	init_function_trace();

	/* All seems OK, enable tracing */
	tracing_disabled = 0;

	atomic_notifier_chain_register(&panic_notifier_list,
				       &trace_panic_notifier);

	register_die_notifier(&trace_die_notifier);

	global_trace.flags = TRACE_ARRAY_FL_GLOBAL;

	INIT_LIST_HEAD(&global_trace.systems);
	INIT_LIST_HEAD(&global_trace.events);
	list_add(&global_trace.list, &ftrace_trace_arrays);

	apply_trace_boot_options();

	register_snapshot_cmd();

	return 0;

out_free_savedcmd:
	free_saved_cmdlines_buffer(savedcmd);
out_free_temp_buffer:
	ring_buffer_free(temp_buffer);
out_rm_hp_state:
	cpuhp_remove_multi_state(CPUHP_TRACE_RB_PREPARE);
out_free_cpumask:
	free_cpumask_var(global_trace.tracing_cpumask);
out_free_buffer_mask:
	free_cpumask_var(tracing_buffer_mask);
out:
	return ret;
}

Project: linux
File: trace.c

int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled)
{
	/* do nothing if flag is already set */
	if (!!(tr->trace_flags & mask) == !!enabled)
		return 0;

	/* Give the tracer a chance to approve the change */
	if (tr->current_trace->flag_changed)
		if (tr->current_trace->flag_changed(tr, mask, !!enabled))
			return -EINVAL;

	if (enabled)
		tr->trace_flags |= mask;
	else
		tr->trace_flags &= ~mask;

	if (mask == TRACE_ITER_RECORD_CMD)
		trace_event_enable_cmd_record(enabled);

	if (mask == TRACE_ITER_RECORD_TGID) {
		if (!tgid_map)
			tgid_map = kzalloc((PID_MAX_DEFAULT + 1) * sizeof(*tgid_map),
					   GFP_KERNEL);
		if (!tgid_map) {
			tr->trace_flags &= ~TRACE_ITER_RECORD_TGID;
			return -ENOMEM;
		}

		trace_event_enable_tgid_record(enabled);
	}

	if (mask == TRACE_ITER_EVENT_FORK)
		trace_event_follow_fork(tr, enabled);

	if (mask == TRACE_ITER_FUNC_FORK)
		ftrace_pid_follow_fork(tr, enabled);

	if (mask == TRACE_ITER_OVERWRITE) {
		ring_buffer_change_overwrite(tr->trace_buffer.buffer, enabled);
#ifdef CONFIG_TRACER_MAX_TRACE
		ring_buffer_change_overwrite(tr->max_buffer.buffer, enabled);
#endif
	}

	if (mask == TRACE_ITER_PRINTK) {
		trace_printk_start_stop_comm(enabled);
		trace_printk_control(enabled);
	}

	return 0;
}

Project: linux
File: trace.c

static int __init boot_alloc_snapshot(char *str)
{
	allocate_snapshot = true;
	/* We also need the main ring buffer expanded */
	ring_buffer_expanded = true;
	return 1;
}

Project: linux
File: trace.c

int tracing_alloc_snapshot(void)
{
	struct trace_array *tr = &global_trace;
	int ret;

	ret = alloc_snapshot(tr);
	WARN_ON(ret < 0);

	return ret;
}

Project: linux
File: trace.c

struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
					  int *ent_cpu, u64 *ent_ts)
{
	return __find_next_entry(iter, ent_cpu, NULL, ent_ts);
}

Project: linux
File: trace.c

int trace_run_command(const char *buf, int (*createfn)(int, char **))
{
	char **argv;
	int argc, ret;

	argc = 0;
	ret = 0;
	argv = argv_split(GFP_KERNEL, buf, &argc);
	if (!argv)
		return -ENOMEM;

	if (argc)
		ret = createfn(argc, argv);

	argv_free(argv);

	return ret;
}

Project: linux
File: trace.c

void tracing_start(void)
{
	struct ring_buffer *buffer;
	unsigned long flags;

	if (tracing_disabled)
		return;

	raw_spin_lock_irqsave(&global_trace.start_lock, flags);
	if (--global_trace.stop_count) {
		if (global_trace.stop_count < 0) {
			/* Someone screwed up their debugging */
			WARN_ON_ONCE(1);
			global_trace.stop_count = 0;
		}
		goto out;
	}

	/* Prevent the buffers from switching */
	arch_spin_lock(&global_trace.max_lock);

	buffer = global_trace.trace_buffer.buffer;
	if (buffer)
		ring_buffer_record_enable(buffer);

#ifdef CONFIG_TRACER_MAX_TRACE
	buffer = global_trace.max_buffer.buffer;
	if (buffer)
		ring_buffer_record_enable(buffer);
#endif

	arch_spin_unlock(&global_trace.max_lock);

 out:
	raw_spin_unlock_irqrestore(&global_trace.start_lock, flags);
}

Project: linux
File: trace.c

static int tracing_wait_pipe(struct file *filp)
{
	struct trace_iterator *iter = filp->private_data;
	int ret;

	while (trace_empty(iter)) {

		if ((filp->f_flags & O_NONBLOCK)) {
			return -EAGAIN;
		}

		/*
		 * 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_tracing_is_on(iter->tr) && iter->pos)
			break;

		mutex_unlock(&iter->mutex);

		ret = wait_on_pipe(iter, false);

		mutex_lock(&iter->mutex);

		if (ret)
			return ret;
	}

	return 1;
}

Project: linux
File: trace.c

void tracing_snapshot(void)
{
	struct trace_array *tr = &global_trace;

	tracing_snapshot_instance(tr);
}

Project: linux
File: trace.c

static void s_stop(struct seq_file *m, void *p)
{
	struct trace_iterator *iter = m->private;

#ifdef CONFIG_TRACER_MAX_TRACE
	if (iter->snapshot && iter->trace->use_max_tr)
		return;
#endif

	if (!iter->snapshot)
		atomic_dec(&trace_record_taskinfo_disabled);

	trace_access_unlock(iter->cpu_file);
	trace_event_read_unlock();
}

Project: linux
File: trace.c

enum print_line_t trace_handle_return(struct trace_seq *s)
{
	return trace_seq_has_overflowed(s) ?
		TRACE_TYPE_PARTIAL_LINE : TRACE_TYPE_HANDLED;
}

Project: linux
File: trace.c

trace_options_core_write(struct file *filp, const char __user *ubuf, size_t cnt,
			 loff_t *ppos)
{
	void *tr_index = filp->private_data;
	struct trace_array *tr;
	unsigned int index;
	unsigned long val;
	int ret;

	get_tr_index(tr_index, &tr, &index);

	ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
	if (ret)
		return ret;

	if (val != 0 && val != 1)
		return -EINVAL;

	mutex_lock(&trace_types_lock);
	ret = set_tracer_flag(tr, 1 << index, val);
	mutex_unlock(&trace_types_lock);

	if (ret < 0)
		return ret;

	*ppos += cnt;

	return cnt;
}

Project: linux
File: trace.c

void trace_printk_init_buffers(void)
{
	if (buffers_allocated)
		return;

	if (alloc_percpu_trace_buffer())
		return;

	/* trace_printk() is for debug use only. Don't use it in production. */

	pr_warn("\n");
	pr_warn("**********************************************************\n");
	pr_warn("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
	pr_warn("**                                                      **\n");
	pr_warn("** trace_printk() being used. Allocating extra memory.  **\n");
	pr_warn("**                                                      **\n");
	pr_warn("** This means that this is a DEBUG kernel and it is     **\n");
	pr_warn("** unsafe for production use.                           **\n");
	pr_warn("**                                                      **\n");
	pr_warn("** If you see this message and you are not debugging    **\n");
	pr_warn("** the kernel, report this immediately to your vendor!  **\n");
	pr_warn("**                                                      **\n");
	pr_warn("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
	pr_warn("**********************************************************\n");

	/* Expand the buffers to set size */
	tracing_update_buffers();

	buffers_allocated = 1;

	/*
	 * trace_printk_init_buffers() can be called by modules.
	 * If that happens, then we need to start cmdline recording
	 * directly here. If the global_trace.buffer is already
	 * allocated here, then this was called by module code.
	 */
	if (global_trace.trace_buffer.buffer)
		tracing_start_cmdline_record();
}

Project: linux
File: trace.c

void trace_buffer_unlock_commit_regs(struct trace_array *tr,
				     struct ring_buffer *buffer,
				     struct ring_buffer_event *event,
				     unsigned long flags, int pc,
				     struct pt_regs *regs)
{
	__buffer_unlock_commit(buffer, event);

	/*
	 * If regs is not set, then skip the following callers:
	 *   trace_buffer_unlock_commit_regs
	 *   event_trigger_unlock_commit
	 *   trace_event_buffer_commit
	 *   trace_event_raw_event_sched_switch
	 * Note, we can still get here via blktrace, wakeup tracer
	 * and mmiotrace, but that's ok if they lose a function or
	 * two. They are that meaningful.
	 */
	ftrace_trace_stack(tr, buffer, flags, regs ? 0 : 4, pc, regs);
	ftrace_trace_userstack(buffer, flags, pc);
}

Project: linux
File: trace.c

static ssize_t tracing_splice_read_pipe(struct file *filp,
					loff_t *ppos,
					struct pipe_inode_info *pipe,
					size_t len,
					unsigned int flags)
{
	struct page *pages_def[PIPE_DEF_BUFFERS];
	struct partial_page partial_def[PIPE_DEF_BUFFERS];
	struct trace_iterator *iter = filp->private_data;
	struct splice_pipe_desc spd = {
		.pages		= pages_def,
		.partial	= partial_def,
		.nr_pages	= 0, /* This gets updated below. */
		.nr_pages_max	= PIPE_DEF_BUFFERS,
		.ops		= &tracing_pipe_buf_ops,
		.spd_release	= tracing_spd_release_pipe,
	};
	ssize_t ret;
	size_t rem;
	unsigned int i;

	if (splice_grow_spd(pipe, &spd))
		return -ENOMEM;

	mutex_lock(&iter->mutex);

	if (iter->trace->splice_read) {
		ret = iter->trace->splice_read(iter, filp,
					       ppos, pipe, len, flags);
		if (ret)
			goto out_err;
	}

	ret = tracing_wait_pipe(filp);
	if (ret <= 0)
		goto out_err;

	if (!iter->ent && !trace_find_next_entry_inc(iter)) {
		ret = -EFAULT;
		goto out_err;
	}

	trace_event_read_lock();
	trace_access_lock(iter->cpu_file);

	/* Fill as many pages as possible. */
	for (i = 0, rem = len; i < spd.nr_pages_max && rem; i++) {
		spd.pages[i] = alloc_page(GFP_KERNEL);
		if (!spd.pages[i])
			break;

		rem = tracing_fill_pipe_page(rem, iter);

		/* Copy the data into the page, so we can start over. */
		ret = trace_seq_to_buffer(&iter->seq,
					  page_address(spd.pages[i]),
					  trace_seq_used(&iter->seq));
		if (ret < 0) {
			__free_page(spd.pages[i]);
			break;
		}
		spd.partial[i].offset = 0;
		spd.partial[i].len = trace_seq_used(&iter->seq);

		trace_seq_init(&iter->seq);
	}

	trace_access_unlock(iter->cpu_file);
	trace_event_read_unlock();
	mutex_unlock(&iter->mutex);

	spd.nr_pages = i;

	if (i)
		ret = splice_to_pipe(pipe, &spd);
	else
		ret = 0;
out:
	splice_shrink_spd(&spd);
	return ret;

out_err:
	mutex_unlock(&iter->mutex);
	goto out;
}

Project: linux
File: trace.c

tracing_buffers_read(struct file *filp, char __user *ubuf,
		     size_t count, loff_t *ppos)
{
	struct ftrace_buffer_info *info = filp->private_data;
	struct trace_iterator *iter = &info->iter;
	ssize_t ret = 0;
	ssize_t size;

	if (!count)
		return 0;

#ifdef CONFIG_TRACER_MAX_TRACE
	if (iter->snapshot && iter->tr->current_trace->use_max_tr)
		return -EBUSY;
#endif

	if (!info->spare) {
		info->spare = ring_buffer_alloc_read_page(iter->trace_buffer->buffer,
							  iter->cpu_file);
		if (IS_ERR(info->spare)) {
			ret = PTR_ERR(info->spare);
			info->spare = NULL;
		} else {
			info->spare_cpu = iter->cpu_file;
		}
	}
	if (!info->spare)
		return ret;

	/* Do we have previous read data to read? */
	if (info->read < PAGE_SIZE)
		goto read;

 again:
	trace_access_lock(iter->cpu_file);
	ret = ring_buffer_read_page(iter->trace_buffer->buffer,
				    &info->spare,
				    count,
				    iter->cpu_file, 0);
	trace_access_unlock(iter->cpu_file);

	if (ret < 0) {
		if (trace_empty(iter)) {
			if ((filp->f_flags & O_NONBLOCK))
				return -EAGAIN;

			ret = wait_on_pipe(iter, false);
			if (ret)
				return ret;

			goto again;
		}
		return 0;
	}

	info->read = 0;
 read:
	size = PAGE_SIZE - info->read;
	if (size > count)
		size = count;

	ret = copy_to_user(ubuf, info->spare + info->read, size);
	if (ret == size)
		return -EFAULT;

	size -= ret;

	*ppos += size;
	info->read += size;

	return size;
}

Project: linux
File: trace.c

trace_poll(struct trace_iterator *iter, struct file *filp, poll_table *poll_table)
{
	struct trace_array *tr = iter->tr;

	/* Iterators are static, they should be filled or empty */
	if (trace_buffer_iter(iter, iter->cpu_file))
		return POLLIN | POLLRDNORM;

	if (tr->trace_flags & TRACE_ITER_BLOCK)
		/*
		 * Always select as readable when in blocking mode
		 */
		return POLLIN | POLLRDNORM;
	else
		return ring_buffer_poll_wait(iter->trace_buffer->buffer, iter->cpu_file,
					     filp, poll_table);
}

Project: linux
File: trace.c

static struct dentry *tracing_dentry_percpu(struct trace_array *tr, int cpu)
{
	struct dentry *d_tracer;

	if (tr->percpu_dir)
		return tr->percpu_dir;

	d_tracer = tracing_get_dentry(tr);
	if (IS_ERR(d_tracer))
		return NULL;

	tr->percpu_dir = tracefs_create_dir("per_cpu", d_tracer);

	WARN_ONCE(!tr->percpu_dir,
		  "Could not create tracefs directory 'per_cpu/%d'\n", cpu);

	return tr->percpu_dir;
}

Project: linux
File: trace.c

void tracing_off(void)
{
	tracer_tracing_off(&global_trace);
}

Project: linux
File: trace.c

int unregister_ftrace_export(struct trace_export *export)
{
	int ret;

	mutex_lock(&ftrace_export_lock);

	ret = rm_ftrace_export(&ftrace_exports_list, export);

	mutex_unlock(&ftrace_export_lock);

	return ret;
}

Project: linux
File: trace.c

static __init int register_snapshot_cmd(void)
{
	return register_ftrace_command(&ftrace_snapshot_cmd);
}

Project: linux
File: trace.c

static int resize_buffer_duplicate_size(struct trace_buffer *trace_buf,
					struct trace_buffer *size_buf, int cpu_id)
{
	int cpu, ret = 0;

	if (cpu_id == RING_BUFFER_ALL_CPUS) {
		for_each_tracing_cpu(cpu) {
			ret = ring_buffer_resize(trace_buf->buffer,
				 per_cpu_ptr(size_buf->data, cpu)->entries, cpu);
			if (ret < 0)
				break;
			per_cpu_ptr(trace_buf->data, cpu)->entries =
				per_cpu_ptr(size_buf->data, cpu)->entries;
		}
	} else {
		ret = ring_buffer_resize(trace_buf->buffer,
				 per_cpu_ptr(size_buf->data, cpu_id)->entries, cpu_id);
		if (ret == 0)
			per_cpu_ptr(trace_buf->data, cpu_id)->entries =
				per_cpu_ptr(size_buf->data, cpu_id)->entries;
	}

	return ret;
}

Project: linux
File: trace.c

static void test_cpu_buff_start(struct trace_iterator *iter)
{
	struct trace_seq *s = &iter->seq;
	struct trace_array *tr = iter->tr;

	if (!(tr->trace_flags & TRACE_ITER_ANNOTATE))
		return;

	if (!(iter->iter_flags & TRACE_FILE_ANNOTATE))
		return;

	if (cpumask_available(iter->started) &&
	    cpumask_test_cpu(iter->cpu, iter->started))
		return;

	if (per_cpu_ptr(iter->trace_buffer->data, iter->cpu)->skipped_entries)
		return;

	if (cpumask_available(iter->started))
		cpumask_set_cpu(iter->cpu, iter->started);

	/* Don't print started cpu buffer for the first entry of the trace */
	if (iter->idx > 1)
		trace_seq_printf(s, "##### CPU %u buffer started ####\n",
				iter->cpu);
}

Project: linux
File: trace.c

static int allocate_cmdlines_buffer(unsigned int val,
				    struct saved_cmdlines_buffer *s)
{
	s->map_cmdline_to_pid = kmalloc(val * sizeof(*s->map_cmdline_to_pid),
					GFP_KERNEL);
	if (!s->map_cmdline_to_pid)
		return -ENOMEM;

	s->saved_cmdlines = kmalloc(val * TASK_COMM_LEN, GFP_KERNEL);
	if (!s->saved_cmdlines) {
		kfree(s->map_cmdline_to_pid);
		return -ENOMEM;
	}

	s->cmdline_idx = 0;
	s->cmdline_num = val;
	memset(&s->map_pid_to_cmdline, NO_CMDLINE_MAP,
	       sizeof(s->map_pid_to_cmdline));
	memset(s->map_cmdline_to_pid, NO_CMDLINE_MAP,
	       val * sizeof(*s->map_cmdline_to_pid));

	return 0;
}

Project: linux
File: trace.c

struct dentry *trace_create_file(const char *name,
				 umode_t mode,
				 struct dentry *parent,
				 void *data,
				 const struct file_operations *fops)
{
	struct dentry *ret;

	ret = tracefs_create_file(name, mode, parent, data, fops);
	if (!ret)
		pr_warn("Could not create tracefs '%s' entry\n", name);

	return ret;
}

Project: linux
File: trace.c

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;

	WARN_ON_ONCE(iter->leftover);

	(*pos)++;

	/* can't go backwards */
	if (iter->idx > i)
		return NULL;

	if (iter->idx < 0)
		ent = trace_find_next_entry_inc(iter);
	else
		ent = iter;

	while (ent && iter->idx < i)
		ent = trace_find_next_entry_inc(iter);

	iter->pos = *pos;

	return ent;
}

Project: linux
File: trace.c

int tracing_alloc_snapshot(void)
{
	WARN_ONCE(1, "Snapshot feature not enabled, but snapshot allocation used");
	return -ENODEV;
}

Project: linux
File: trace.c

static void *eval_map_start(struct seq_file *m, loff_t *pos)
{
	union trace_eval_map_item *v;
	loff_t l = 0;

	mutex_lock(&trace_eval_mutex);

	v = trace_eval_maps;
	if (v)
		v++;

	while (v && l < *pos) {
		v = eval_map_next(m, v, &l);
	}

	return v;
}

Project: linux
File: trace.c

static int set_tracer_option(struct trace_array *tr, char *cmp, int neg)
{
	struct tracer *trace = tr->current_trace;
	struct tracer_flags *tracer_flags = trace->flags;
	struct tracer_opt *opts = NULL;
	int i;

	for (i = 0; tracer_flags->opts[i].name; i++) {
		opts = &tracer_flags->opts[i];

		if (strcmp(cmp, opts->name) == 0)
			return __set_tracer_option(tr, trace->flags, opts, neg);
	}

	return -EINVAL;
}

Project: linux
File: trace.c

trace_options_read(struct file *filp, char __user *ubuf, size_t cnt,
			loff_t *ppos)
{
	struct trace_option_dentry *topt = filp->private_data;
	char *buf;

	if (topt->flags->val & topt->opt->bit)
		buf = "1\n";
	else
		buf = "0\n";

	return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
}

Project: linux
File: trace.c

tracing_free_buffer_write(struct file *filp, const char __user *ubuf,
			  size_t cnt, loff_t *ppos)
{
	/*
	 * There is no need to read what the user has written, this function
	 * is just to make sure that there is no error when "echo" is used
	 */

	*ppos += cnt;

	return cnt;
}

Project: linux
File: trace.c

static int tracing_set_clock(struct trace_array *tr, const char *clockstr)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(trace_clocks); i++) {
		if (strcmp(trace_clocks[i].name, clockstr) == 0)
			break;
	}
	if (i == ARRAY_SIZE(trace_clocks))
		return -EINVAL;

	mutex_lock(&trace_types_lock);

	tr->clock_id = i;

	ring_buffer_set_clock(tr->trace_buffer.buffer, trace_clocks[i].func);

	/*
	 * New clock may not be consistent with the previous clock.
	 * Reset the buffer so that it doesn't have incomparable timestamps.
	 */
	tracing_reset_online_cpus(&tr->trace_buffer);

#ifdef CONFIG_TRACER_MAX_TRACE
	if (tr->max_buffer.buffer)
		ring_buffer_set_clock(tr->max_buffer.buffer, trace_clocks[i].func);
	tracing_reset_online_cpus(&tr->max_buffer);
#endif

	mutex_unlock(&trace_types_lock);

	return 0;
}

Project: linux
File: trace.c

void tracing_snapshot(void)
{
	WARN_ONCE(1, "Snapshot feature not enabled, but internal snapshot used");
}

Project: linux
File: trace.c

tracing_saved_cmdlines_size_write(struct file *filp, const char __user *ubuf,
				  size_t cnt, loff_t *ppos)
{
	unsigned long val;
	int ret;

	ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
	if (ret)
		return ret;

	/* must have at least 1 entry or less than PID_MAX_DEFAULT */
	if (!val || val > PID_MAX_DEFAULT)
		return -EINVAL;

	ret = tracing_resize_saved_cmdlines((unsigned int)val);
	if (ret < 0)
		return ret;

	*ppos += cnt;

	return cnt;
}

Project: linux
File: trace.c

__find_next_entry(struct trace_iterator *iter, int *ent_cpu,
		  unsigned long *missing_events, u64 *ent_ts)
{
	struct ring_buffer *buffer = iter->trace_buffer->buffer;
	struct trace_entry *ent, *next = NULL;
	unsigned long lost_events = 0, next_lost = 0;
	int cpu_file = iter->cpu_file;
	u64 next_ts = 0, ts;
	int next_cpu = -1;
	int next_size = 0;
	int cpu;

	/*
	 * If we are in a per_cpu trace file, don't bother by iterating over
	 * all cpu and peek directly.
	 */
	if (cpu_file > RING_BUFFER_ALL_CPUS) {
		if (ring_buffer_empty_cpu(buffer, cpu_file))
			return NULL;
		ent = peek_next_entry(iter, cpu_file, ent_ts, missing_events);
		if (ent_cpu)
			*ent_cpu = cpu_file;

		return ent;
	}

	for_each_tracing_cpu(cpu) {

		if (ring_buffer_empty_cpu(buffer, cpu))
			continue;

		ent = peek_next_entry(iter, cpu, &ts, &lost_events);

		/*
		 * Pick the entry with the smallest timestamp:
		 */
		if (ent && (!next || ts < next_ts)) {
			next = ent;
			next_cpu = cpu;
			next_ts = ts;
			next_lost = lost_events;
			next_size = iter->ent_size;
		}
	}

	iter->ent_size = next_size;

	if (ent_cpu)
		*ent_cpu = next_cpu;

	if (ent_ts)
		*ent_ts = next_ts;

	if (missing_events)
		*missing_events = next_lost;

	return next;
}

Project: linux
File: trace.c

int trace_array_printk(struct trace_array *tr,
		       unsigned long ip, const char *fmt, ...)
{
	int ret;
	va_list ap;

	if (!(global_trace.trace_flags & TRACE_ITER_PRINTK))
		return 0;

	va_start(ap, fmt);
	ret = trace_array_vprintk(tr, ip, fmt, ap);
	va_end(ap);
	return ret;
}

Project: linux
File: trace.c

__init static int clear_boot_tracer(void)
{
	/*
	 * The default tracer at boot buffer is an init section.
	 * This function is called in lateinit. If we did not
	 * find the boot tracer, then clear it out, to prevent
	 * later registration from accessing the buffer that is
	 * about to be freed.
	 */
	if (!default_bootup_tracer)
		return 0;

	printk(KERN_INFO "ftrace bootup tracer '%s' not registered.\n",
	       default_bootup_tracer);
	default_bootup_tracer = NULL;

	return 0;
}

Project: linux
File: trace.c

static inline char *get_saved_cmdlines(int idx)
{
	return &savedcmd->saved_cmdlines[idx * TASK_COMM_LEN];
}

Project: linux
File: trace.c

tracing_fill_pipe_page(size_t rem, struct trace_iterator *iter)
{
	size_t count;
	int save_len;
	int ret;

	/* Seq buffer is page-sized, exactly what we need. */
	for (;;) {
		save_len = iter->seq.seq.len;
		ret = print_trace_line(iter);

		if (trace_seq_has_overflowed(&iter->seq)) {
			iter->seq.seq.len = save_len;
			break;
		}

		/*
		 * This should not be hit, because it should only
		 * be set if the iter->seq overflowed. But check it
		 * anyway to be safe.
		 */
		if (ret == TRACE_TYPE_PARTIAL_LINE) {
			iter->seq.seq.len = save_len;
			break;
		}

		count = trace_seq_used(&iter->seq) - save_len;
		if (rem < count) {
			rem = 0;
			iter->seq.seq.len = save_len;
			break;
		}

		if (ret != TRACE_TYPE_NO_CONSUME)
			trace_consume(iter);
		rem -= count;
		if (!trace_find_next_entry_inc(iter))	{
			rem = 0;
			iter->ent = NULL;
			break;
		}
	}

	return rem;
}

Project: linux
File: trace.c

void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
{
	/* use static because iter can be a bit big for the stack */
	static struct trace_iterator iter;
	static atomic_t dump_running;
	struct trace_array *tr = &global_trace;
	unsigned int old_userobj;
	unsigned long flags;
	int cnt = 0, cpu;

	/* Only allow one dump user at a time. */
	if (atomic_inc_return(&dump_running) != 1) {
		atomic_dec(&dump_running);
		return;
	}

	/*
	 * Always turn off tracing when we dump.
	 * We don't need to show trace output of what happens
	 * between multiple crashes.
	 *
	 * If the user does a sysrq-z, then they can re-enable
	 * tracing with echo 1 > tracing_on.
	 */
	tracing_off();

	local_irq_save(flags);

	/* Simulate the iterator */
	trace_init_global_iter(&iter);

	for_each_tracing_cpu(cpu) {
		atomic_inc(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled);
	}

	old_userobj = tr->trace_flags & TRACE_ITER_SYM_USEROBJ;

	/* don't look at user memory in panic mode */
	tr->trace_flags &= ~TRACE_ITER_SYM_USEROBJ;

	switch (oops_dump_mode) {
	case DUMP_ALL:
		iter.cpu_file = RING_BUFFER_ALL_CPUS;
		break;
	case DUMP_ORIG:
		iter.cpu_file = raw_smp_processor_id();
		break;
	case DUMP_NONE:
		goto out_enable;
	default:
		printk(KERN_TRACE "Bad dumping mode, switching to all CPUs dump\n");
		iter.cpu_file = RING_BUFFER_ALL_CPUS;
	}

	printk(KERN_TRACE "Dumping ftrace buffer:\n");

	/* Did function tracer already get disabled? */
	if (ftrace_is_dead()) {
		printk("# WARNING: FUNCTION TRACING IS CORRUPTED\n");
		printk("#          MAY BE MISSING FUNCTION EVENTS\n");
	}

	/*
	 * 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.
	 */

	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 (trace_find_next_entry_inc(&iter) != NULL) {
			int ret;

			ret = print_trace_line(&iter);
			if (ret != TRACE_TYPE_NO_CONSUME)
				trace_consume(&iter);
		}
		touch_nmi_watchdog();

		trace_printk_seq(&iter.seq);
	}

	if (!cnt)
		printk(KERN_TRACE "   (ftrace buffer empty)\n");
	else
		printk(KERN_TRACE "---------------------------------\n");

 out_enable:
	tr->trace_flags |= old_userobj;

	for_each_tracing_cpu(cpu) {
		atomic_dec(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled);
	}
 	atomic_dec(&dump_running);
	local_irq_restore(flags);
}

Project: linux
File: trace.c

trace_options_write(struct file *filp, const char __user *ubuf, size_t cnt,
			 loff_t *ppos)
{
	struct trace_option_dentry *topt = filp->private_data;
	unsigned long val;
	int ret;

	ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
	if (ret)
		return ret;

	if (val != 0 && val != 1)
		return -EINVAL;

	if (!!(topt->flags->val & topt->opt->bit) != val) {
		mutex_lock(&trace_types_lock);
		ret = __set_tracer_option(topt->tr, topt->flags,
					  topt->opt, !val);
		mutex_unlock(&trace_types_lock);
		if (ret)
			return ret;
	}

	*ppos += cnt;

	return cnt;
}

Project: linux
File: trace.c

static void trace_consume(struct trace_iterator *iter)
{
	ring_buffer_consume(iter->trace_buffer->buffer, iter->cpu, &iter->ts,
			    &iter->lost_events);
}

Project: linux
File: trace.c

int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set)
{
	if (tracer->enabled && (mask & TRACE_ITER_OVERWRITE) && !set)
		return -1;

	return 0;
}

Project: linux
File: trace.c

static void create_trace_options_dir(struct trace_array *tr)
{
	struct dentry *t_options;
	bool top_level = tr == &global_trace;
	int i;

	t_options = trace_options_init_dentry(tr);
	if (!t_options)
		return;

	for (i = 0; trace_options[i]; i++) {
		if (top_level ||
		    !((1 << i) & TOP_LEVEL_TRACE_FLAGS))
			create_trace_option_core_file(tr, trace_options[i], i);
	}
}

Project: linux
File: trace.c

int is_tracing_stopped(void)
{
	return global_trace.stop_count;
}

Project: linux
File: trace.c

int __trace_bputs(unsigned long ip, const char *str)
{
	struct ring_buffer_event *event;
	struct ring_buffer *buffer;
	struct bputs_entry *entry;
	unsigned long irq_flags;
	int size = sizeof(struct bputs_entry);
	int pc;

	if (!(global_trace.trace_flags & TRACE_ITER_PRINTK))
		return 0;

	pc = preempt_count();

	if (unlikely(tracing_selftest_running || tracing_disabled))
		return 0;

	local_save_flags(irq_flags);
	buffer = global_trace.trace_buffer.buffer;
	event = __trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size,
					    irq_flags, pc);
	if (!event)
		return 0;

	entry = ring_buffer_event_data(event);
	entry->ip			= ip;
	entry->str			= str;

	__buffer_unlock_commit(buffer, event);
	ftrace_trace_stack(&global_trace, buffer, irq_flags, 4, pc, NULL);

	return 1;
}

Project: linux
File: trace.c

static int show_traces_open(struct inode *inode, struct file *file)
{
	struct trace_array *tr = inode->i_private;
	struct seq_file *m;
	int ret;

	if (tracing_disabled)
		return -ENODEV;

	ret = seq_open(file, &show_traces_seq_ops);
	if (ret)
		return ret;

	m = file->private_data;
	m->private = tr;

	return 0;
}

Project: linux
File: trace.c

void __init early_trace_init(void)
{
	if (tracepoint_printk) {
		tracepoint_print_iter =
			kmalloc(sizeof(*tracepoint_print_iter), GFP_KERNEL);
		if (WARN_ON(!tracepoint_print_iter))
			tracepoint_printk = 0;
		else
			static_key_enable(&tracepoint_printk_key.key);
	}
	tracer_alloc_buffers();
}

Project: linux
File: trace.c

static void __init trace_eval_init(void)
{
	int len;

	len = __stop_ftrace_eval_maps - __start_ftrace_eval_maps;
	trace_insert_eval_map(NULL, __start_ftrace_eval_maps, len);
}

Project: linux
File: trace.c

tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt,
		       loff_t *ppos)
{
	struct seq_file *m = filp->private_data;
	struct trace_iterator *iter = m->private;
	struct trace_array *tr = iter->tr;
	unsigned long val;
	int ret;

	ret = tracing_update_buffers();
	if (ret < 0)
		return ret;

	ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
	if (ret)
		return ret;

	mutex_lock(&trace_types_lock);

	if (tr->current_trace->use_max_tr) {
		ret = -EBUSY;
		goto out;
	}

	switch (val) {
	case 0:
		if (iter->cpu_file != RING_BUFFER_ALL_CPUS) {
			ret = -EINVAL;
			break;
		}
		if (tr->allocated_snapshot)
			free_snapshot(tr);
		break;
	case 1:
/* Only allow per-cpu swap if the ring buffer supports it */
#ifndef CONFIG_RING_BUFFER_ALLOW_SWAP
		if (iter->cpu_file != RING_BUFFER_ALL_CPUS) {
			ret = -EINVAL;
			break;
		}
#endif
		if (!tr->allocated_snapshot) {
			ret = alloc_snapshot(tr);
			if (ret < 0)
				break;
		}
		local_irq_disable();
		/* Now, we're going to swap */
		if (iter->cpu_file == RING_BUFFER_ALL_CPUS)
			update_max_tr(tr, current, smp_processor_id());
		else
			update_max_tr_single(tr, current, iter->cpu_file);
		local_irq_enable();
		break;
	default:
		if (tr->allocated_snapshot) {
			if (iter->cpu_file == RING_BUFFER_ALL_CPUS)
				tracing_reset_online_cpus(&tr->max_buffer);
			else
				tracing_reset(&tr->max_buffer, iter->cpu_file);
		}
		break;
	}

	if (ret >= 0) {
		*ppos += cnt;
		ret = cnt;
	}
out:
	mutex_unlock(&trace_types_lock);
	return ret;
}

Project: linux
File: trace.c

__buffer_unlock_commit(struct ring_buffer *buffer, struct ring_buffer_event *event)
{
	__this_cpu_write(trace_taskinfo_save, true);

	/* If this is the temp buffer, we need to commit fully */
	if (this_cpu_read(trace_buffered_event) == event) {
		/* Length is in event->array[0] */
		ring_buffer_write(buffer, event->array[0], &event->array[1]);
		/* Release the temp buffer */
		this_cpu_dec(trace_buffered_event_cnt);
	} else
		ring_buffer_unlock_commit(buffer, event);
}

Project: linux
File: trace.c

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));
}

Project: linux
File: trace.c

static void eval_map_stop(struct seq_file *m, void *v)
{
	mutex_unlock(&trace_eval_mutex);
}

Project: linux
File: trace.c

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;

	/*
	 * Avoid more than one consumer on a single file descriptor
	 * This is just a matter of traces coherency, the ring buffer itself
	 * is protected.
	 */
	mutex_lock(&iter->mutex);

	/* return any leftover data */
	sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
	if (sret != -EBUSY)
		goto out;

	trace_seq_init(&iter->seq);

	if (iter->trace->read) {
		sret = iter->trace->read(iter, filp, ubuf, cnt, ppos);
		if (sret)
			goto out;
	}

waitagain:
	sret = tracing_wait_pipe(filp);
	if (sret <= 0)
		goto out;

	/* stop when tracing is finished */
	if (trace_empty(iter)) {
		sret = 0;
		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));
	cpumask_clear(iter->started);
	iter->pos = -1;

	trace_event_read_lock();
	trace_access_lock(iter->cpu_file);
	while (trace_find_next_entry_inc(iter) != NULL) {
		enum print_line_t ret;
		int save_len = iter->seq.seq.len;

		ret = print_trace_line(iter);
		if (ret == TRACE_TYPE_PARTIAL_LINE) {
			/* don't print partial lines */
			iter->seq.seq.len = save_len;
			break;
		}
		if (ret != TRACE_TYPE_NO_CONSUME)
			trace_consume(iter);

		if (trace_seq_used(&iter->seq) >= cnt)
			break;

		/*
		 * Setting the full flag means we reached the trace_seq buffer
		 * size and we should leave by partial output condition above.
		 * One of the trace_seq_* functions is not used properly.
		 */
		WARN_ONCE(iter->seq.full, "full flag set for trace type %d",
			  iter->ent->type);
	}
	trace_access_unlock(iter->cpu_file);
	trace_event_read_unlock();

	/* Now copy what we have to the user */
	sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
	if (iter->seq.seq.readpos >= trace_seq_used(&iter->seq))
		trace_seq_init(&iter->seq);

	/*
	 * If there was nothing to send to user, in spite of consuming trace
	 * entries, go back to wait for more entries.
	 */
	if (sret == -EBUSY)
		goto waitagain;

out:
	mutex_unlock(&iter->mutex);

	return sret;
}

Project: linux
File: trace.c

static void buffer_pipe_buf_release(struct pipe_inode_info *pipe,
				    struct pipe_buffer *buf)
{
	struct buffer_ref *ref = (struct buffer_ref *)buf->private;

	if (--ref->ref)
		return;

	ring_buffer_free_read_page(ref->buffer, ref->cpu, ref->page);
	kfree(ref);
	buf->private = 0;
}

Project: linux
File: trace.c

static void *saved_tgids_start(struct seq_file *m, loff_t *pos)
{
	void *v;
	loff_t l = 0;

	if (!tgid_map)
		return NULL;

	v = &tgid_map[0];
	while (l <= *pos) {
		v = saved_tgids_next(m, v, &l);
		if (!v)
			return NULL;
	}

	return v;
}

Project: linux
File: trace.c

static bool tracing_record_taskinfo_skip(int flags)
{
	if (unlikely(!(flags & (TRACE_RECORD_CMDLINE | TRACE_RECORD_TGID))))
		return true;
	if (atomic_read(&trace_record_taskinfo_disabled) || !tracing_is_on())
		return true;
	if (!__this_cpu_read(trace_taskinfo_save))
		return true;
	return false;
}

Project: linux
File: trace.c

void trace_default_header(struct seq_file *m)
{
	struct trace_iterator *iter = m->private;
	struct trace_array *tr = iter->tr;
	unsigned long trace_flags = tr->trace_flags;

	if (!(trace_flags & TRACE_ITER_CONTEXT_INFO))
		return;

	if (iter->iter_flags & TRACE_FILE_LAT_FMT) {
		/* print nothing if the buffers are empty */
		if (trace_empty(iter))
			return;
		print_trace_header(m, iter);
		if (!(trace_flags & TRACE_ITER_VERBOSE))
			print_lat_help_header(m);
	} else {
		if (!(trace_flags & TRACE_ITER_VERBOSE)) {
			if (trace_flags & TRACE_ITER_IRQ_INFO)
				print_func_help_header_irq(iter->trace_buffer,
							   m, trace_flags);
			else
				print_func_help_header(iter->trace_buffer, m,
						       trace_flags);
		}
	}
}

Project: linux
File: trace.c

static void add_tracer_options(struct trace_array *tr, struct tracer *t)
{
	/* Only enable if the directory has been created already. */
	if (!tr->dir)
		return;

	create_trace_option_files(tr, t);
}

Project: linux
File: trace.c

static int __init set_cmdline_ftrace(char *str)
{
	strlcpy(bootup_tracer_buf, str, MAX_TRACER_SIZE);
	default_bootup_tracer = bootup_tracer_buf;
	/* We are using ftrace early, expand it */
	ring_buffer_expanded = true;
	return 1;
}

Project: linux
File: trace.c

static int tracing_release(struct inode *inode, struct file *file)
{
	struct trace_array *tr = inode->i_private;
	struct seq_file *m = file->private_data;
	struct trace_iterator *iter;
	int cpu;

	if (!(file->f_mode & FMODE_READ)) {
		trace_array_put(tr);
		return 0;
	}

	/* Writes do not use seq_file */
	iter = m->private;
	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);

	if (!iter->snapshot)
		/* reenable tracing if it was previously enabled */
		tracing_start_tr(tr);

	__trace_array_put(tr);

	mutex_unlock(&trace_types_lock);

	mutex_destroy(&iter->mutex);
	free_cpumask_var(iter->started);
	kfree(iter->trace);
	kfree(iter->buffer_iter);
	seq_release_private(inode, file);

	return 0;
}

Project: linux
File: trace.c

tracing_max_lat_write(struct file *filp, const char __user *ubuf,
		      size_t cnt, loff_t *ppos)
{
	return tracing_nsecs_write(filp->private_data, ubuf, cnt, ppos);
}

Project: linux
File: trace.c

static int save_selftest(struct tracer *type)
{
	struct trace_selftests *selftest;

	selftest = kmalloc(sizeof(*selftest), GFP_KERNEL);
	if (!selftest)
		return -ENOMEM;

	selftest->type = type;
	list_add(&selftest->list, &postponed_selftests);
	return 0;
}

Project: linux
File: trace.c

static int tracing_clock_open(struct inode *inode, struct file *file)
{
	struct trace_array *tr = inode->i_private;
	int ret;

	if (tracing_disabled)
		return -ENODEV;

	if (trace_array_get(tr))
		return -ENODEV;

	ret = single_open(file, tracing_clock_show, inode->i_private);
	if (ret < 0)
		trace_array_put(tr);

	return ret;
}

Project: linux
File: trace.c

static int trace_set_options(struct trace_array *tr, char *option)
{
	char *cmp;
	int neg = 0;
	int ret = -ENODEV;
	int i;
	size_t orig_len = strlen(option);

	cmp = strstrip(option);

	if (strncmp(cmp, "no", 2) == 0) {
		neg = 1;
		cmp += 2;
	}

	mutex_lock(&trace_types_lock);

	for (i = 0; trace_options[i]; i++) {
		if (strcmp(cmp, trace_options[i]) == 0) {
			ret = set_tracer_flag(tr, 1 << i, !neg);
			break;
		}
	}

	/* If no option could be set, test the specific tracer options */
	if (!trace_options[i])
		ret = set_tracer_option(tr, cmp, neg);

	mutex_unlock(&trace_types_lock);

	/*
	 * If the first trailing whitespace is replaced with '\0' by strstrip,
	 * turn it back into a space.
	 */
	if (orig_len > strlen(option))
		option[strlen(option)] = ' ';

	return ret;
}

Project: linux
File: trace.c

static __init int init_trace_selftests(void)
{
	struct trace_selftests *p, *n;
	struct tracer *t, **last;
	int ret;

	selftests_can_run = true;

	mutex_lock(&trace_types_lock);

	if (list_empty(&postponed_selftests))
		goto out;

	pr_info("Running postponed tracer tests:\n");

	list_for_each_entry_safe(p, n, &postponed_selftests, list) {
		ret = run_tracer_selftest(p->type);
		/* If the test fails, then warn and remove from available_tracers */
		if (ret < 0) {
			WARN(1, "tracer: %s failed selftest, disabling\n",
			     p->type->name);
			last = &trace_types;
			for (t = trace_types; t; t = t->next) {
				if (t == p->type) {
					*last = t->next;
					break;
				}
				last = &t->next;
			}
		}
		list_del(&p->list);
		kfree(p);
	}

 out:
	mutex_unlock(&trace_types_lock);

	return 0;
}

Project: linux
File: trace.c

allocate_trace_buffer(struct trace_array *tr, struct trace_buffer *buf, int size)
{
	enum ring_buffer_flags rb_flags;

	rb_flags = tr->trace_flags & TRACE_ITER_OVERWRITE ? RB_FL_OVERWRITE : 0;

	buf->tr = tr;

	buf->buffer = ring_buffer_alloc(size, rb_flags);
	if (!buf->buffer)
		return -ENOMEM;

	buf->data = alloc_percpu(struct trace_array_cpu);
	if (!buf->data) {
		ring_buffer_free(buf->buffer);
		buf->buffer = NULL;
		return -ENOMEM;
	}

	/* Allocate the first page for all buffers */
	set_buffer_entries(&tr->trace_buffer,
			   ring_buffer_size(tr->trace_buffer.buffer, 0));

	return 0;
}

Project: linux
File: trace.c

void trace_init_global_iter(struct trace_iterator *iter)
{
	iter->tr = &global_trace;
	iter->trace = iter->tr->current_trace;
	iter->cpu_file = RING_BUFFER_ALL_CPUS;
	iter->trace_buffer = &global_trace.trace_buffer;

	if (iter->trace && iter->trace->open)
		iter->trace->open(iter);

	/* Annotate start of buffers if we had overruns */
	if (ring_buffer_overruns(iter->trace_buffer->buffer))
		iter->iter_flags |= TRACE_FILE_ANNOTATE;

	/* Output in nanoseconds only if we are using a clock in nanoseconds. */
	if (trace_clocks[iter->tr->clock_id].in_ns)
		iter->iter_flags |= TRACE_FILE_TIME_IN_NS;
}

Project: linux
File: trace.c

static int tracing_snapshot_open(struct inode *inode, struct file *file)
{
	struct trace_array *tr = inode->i_private;
	struct trace_iterator *iter;
	struct seq_file *m;
	int ret = 0;

	if (trace_array_get(tr) < 0)
		return -ENODEV;

	if (file->f_mode & FMODE_READ) {
		iter = __tracing_open(inode, file, true);
		if (IS_ERR(iter))
			ret = PTR_ERR(iter);
	} else {
		/* Writes still need the seq_file to hold the private data */
		ret = -ENOMEM;
		m = kzalloc(sizeof(*m), GFP_KERNEL);
		if (!m)
			goto out;
		iter = kzalloc(sizeof(*iter), GFP_KERNEL);
		if (!iter) {
			kfree(m);
			goto out;
		}
		ret = 0;

		iter->tr = tr;
		iter->trace_buffer = &tr->max_buffer;
		iter->cpu_file = tracing_get_cpu(inode);
		m->private = iter;
		file->private_data = m;
	}
out:
	if (ret < 0)
		trace_array_put(tr);

	return ret;
}

Project: linux
File: trace.c

static int tracing_eval_map_open(struct inode *inode, struct file *filp)
{
	if (tracing_disabled)
		return -ENODEV;

	return seq_open(filp, &tracing_eval_map_seq_ops);
}

Project: linux
File: trace.c

trace_event_setup(struct ring_buffer_event *event,
		  int type, unsigned long flags, int pc)
{
	struct trace_entry *ent = ring_buffer_event_data(event);

	tracing_generic_entry_update(ent, flags, pc);
	ent->type = type;
}

Project: linux
File: trace.c

void tracing_reset(struct trace_buffer *buf, int cpu)
{
	struct ring_buffer *buffer = buf->buffer;

	if (!buffer)
		return;

	ring_buffer_record_disable(buffer);

	/* Make sure all commits have finished */
	synchronize_sched();
	ring_buffer_reset_cpu(buffer, cpu);

	ring_buffer_record_enable(buffer);
}

Project: linux
File: trace.c

trace_ok_for_array(struct tracer *t, struct trace_array *tr)
{
	return (tr->flags & TRACE_ARRAY_FL_GLOBAL) || t->allow_instances;
}

Project: linux
File: trace.c

static int allocate_trace_buffers(struct trace_array *tr, int size)
{
	int ret;

	ret = allocate_trace_buffer(tr, &tr->trace_buffer, size);
	if (ret)
		return ret;

#ifdef CONFIG_TRACER_MAX_TRACE
	ret = allocate_trace_buffer(tr, &tr->max_buffer,
				    allocate_snapshot ? size : 1);
	if (WARN_ON(ret)) {
		ring_buffer_free(tr->trace_buffer.buffer);
		tr->trace_buffer.buffer = NULL;
		free_percpu(tr->trace_buffer.data);
		tr->trace_buffer.data = NULL;
		return -ENOMEM;
	}
	tr->allocated_snapshot = allocate_snapshot;

	/*
	 * Only the top level trace array gets its snapshot allocated
	 * from the kernel command line.
	 */
	allocate_snapshot = false;
#endif
	return 0;
}

Project: linux
File: trace.c

void disable_trace_on_warning(void)
{
	if (__disable_trace_on_warning)
		tracing_off();
}

Project: linux
File: trace.c

void tracing_record_taskinfo(struct task_struct *task, int flags)
{
	bool done;

	if (tracing_record_taskinfo_skip(flags))
		return;

	/*
	 * Record as much task information as possible. If some fail, continue
	 * to try to record the others.
	 */
	done = !(flags & TRACE_RECORD_CMDLINE) || trace_save_cmdline(task);
	done &= !(flags & TRACE_RECORD_TGID) || trace_save_tgid(task);

	/* If recording any information failed, retry again soon. */
	if (!done)
		return;

	__this_cpu_write(trace_taskinfo_save, false);
}

Project: linux
File: trace.c

tracing_buffers_splice_read(struct file *file, loff_t *ppos,
			    struct pipe_inode_info *pipe, size_t len,
			    unsigned int flags)
{
	struct ftrace_buffer_info *info = file->private_data;
	struct trace_iterator *iter = &info->iter;
	struct partial_page partial_def[PIPE_DEF_BUFFERS];
	struct page *pages_def[PIPE_DEF_BUFFERS];
	struct splice_pipe_desc spd = {
		.pages		= pages_def,
		.partial	= partial_def,
		.nr_pages_max	= PIPE_DEF_BUFFERS,
		.ops		= &buffer_pipe_buf_ops,
		.spd_release	= buffer_spd_release,
	};
	struct buffer_ref *ref;
	int entries, i;
	ssize_t ret = 0;

#ifdef CONFIG_TRACER_MAX_TRACE
	if (iter->snapshot && iter->tr->current_trace->use_max_tr)
		return -EBUSY;
#endif

	if (*ppos & (PAGE_SIZE - 1))
		return -EINVAL;

	if (len & (PAGE_SIZE - 1)) {
		if (len < PAGE_SIZE)
			return -EINVAL;
		len &= PAGE_MASK;
	}

	if (splice_grow_spd(pipe, &spd))
		return -ENOMEM;

 again:
	trace_access_lock(iter->cpu_file);
	entries = ring_buffer_entries_cpu(iter->trace_buffer->buffer, iter->cpu_file);

	for (i = 0; i < spd.nr_pages_max && len && entries; i++, len -= PAGE_SIZE) {
		struct page *page;
		int r;

		ref = kzalloc(sizeof(*ref), GFP_KERNEL);
		if (!ref) {
			ret = -ENOMEM;
			break;
		}

		ref->ref = 1;
		ref->buffer = iter->trace_buffer->buffer;
		ref->page = ring_buffer_alloc_read_page(ref->buffer, iter->cpu_file);
		if (IS_ERR(ref->page)) {
			ret = PTR_ERR(ref->page);
			ref->page = NULL;
			kfree(ref);
			break;
		}
		ref->cpu = iter->cpu_file;

		r = ring_buffer_read_page(ref->buffer, &ref->page,
					  len, iter->cpu_file, 1);
		if (r < 0) {
			ring_buffer_free_read_page(ref->buffer, ref->cpu,
						   ref->page);
			kfree(ref);
			break;
		}

		page = virt_to_page(ref->page);

		spd.pages[i] = page;
		spd.partial[i].len = PAGE_SIZE;
		spd.partial[i].offset = 0;
		spd.partial[i].private = (unsigned long)ref;
		spd.nr_pages++;
		*ppos += PAGE_SIZE;

		entries = ring_buffer_entries_cpu(iter->trace_buffer->buffer, iter->cpu_file);
	}

	trace_access_unlock(iter->cpu_file);
	spd.nr_pages = i;

	/* did we read anything? */
	if (!spd.nr_pages) {
		if (ret)
			goto out;

		ret = -EAGAIN;
		if ((file->f_flags & O_NONBLOCK) || (flags & SPLICE_F_NONBLOCK))
			goto out;

		ret = wait_on_pipe(iter, true);
		if (ret)
			goto out;

		goto again;
	}

	ret = splice_to_pipe(pipe, &spd);
out:
	splice_shrink_spd(&spd);

	return ret;
}

Project: linux
File: trace.c

unsigned long long ns2usecs(u64 nsec)
{
	nsec += 500;
	do_div(nsec, 1000);
	return nsec;
}

Project: linux
File: trace.c

static void update_tracer_options(struct trace_array *tr)
{
	mutex_lock(&trace_types_lock);
	__update_tracer_options(tr);
	mutex_unlock(&trace_types_lock);
}

Project: linux
File: trace.c

static void output_printk(struct trace_event_buffer *fbuffer)
{
	struct trace_event_call *event_call;
	struct trace_event *event;
	unsigned long flags;
	struct trace_iterator *iter = tracepoint_print_iter;

	/* We should never get here if iter is NULL */
	if (WARN_ON_ONCE(!iter))
		return;

	event_call = fbuffer->trace_file->event_call;
	if (!event_call || !event_call->event.funcs ||
	    !event_call->event.funcs->trace)
		return;

	event = &fbuffer->trace_file->event_call->event;

	spin_lock_irqsave(&tracepoint_iter_lock, flags);
	trace_seq_init(&iter->seq);
	iter->ent = fbuffer->entry;
	event_call->event.funcs->trace(iter, 0, event);
	trace_seq_putc(&iter->seq, 0);
	printk("%s", iter->seq.buffer);

	spin_unlock_irqrestore(&tracepoint_iter_lock, flags);
}

Project: linux
File: trace.c

void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
		   int pc)
{
	struct ring_buffer *buffer = tr->trace_buffer.buffer;

	if (rcu_is_watching()) {
		__ftrace_trace_stack(buffer, flags, skip, pc, NULL);
		return;
	}

	/*
	 * When an NMI triggers, RCU is enabled via rcu_nmi_enter(),
	 * but if the above rcu_is_watching() failed, then the NMI
	 * triggered someplace critical, and rcu_irq_enter() should
	 * not be called from NMI.
	 */
	if (unlikely(in_nmi()))
		return;

	/*
	 * It is possible that a function is being traced in a
	 * location that RCU is not watching. A call to
	 * rcu_irq_enter() will make sure that it is, but there's
	 * a few internal rcu functions that could be traced
	 * where that wont work either. In those cases, we just
	 * do nothing.
	 */
	if (unlikely(rcu_irq_enter_disabled()))
		return;

	rcu_irq_enter_irqson();
	__ftrace_trace_stack(buffer, flags, skip, pc, NULL);
	rcu_irq_exit_irqson();
}

Project: linux
File: trace.c

static int tracing_resize_saved_cmdlines(unsigned int val)
{
	struct saved_cmdlines_buffer *s, *savedcmd_temp;

	s = kmalloc(sizeof(*s), GFP_KERNEL);
	if (!s)
		return -ENOMEM;

	if (allocate_cmdlines_buffer(val, s) < 0) {
		kfree(s);
		return -ENOMEM;
	}

	arch_spin_lock(&trace_cmdline_lock);
	savedcmd_temp = savedcmd;
	savedcmd = s;
	arch_spin_unlock(&trace_cmdline_lock);
	free_saved_cmdlines_buffer(savedcmd_temp);

	return 0;
}

Project: linux
File: trace.c

trace_insert_eval_map_file(struct module *mod, struct trace_eval_map **start,
			   int len)
{
	struct trace_eval_map **stop;
	struct trace_eval_map **map;
	union trace_eval_map_item *map_array;
	union trace_eval_map_item *ptr;

	stop = start + len;

	/*
	 * The trace_eval_maps contains the map plus a head and tail item,
	 * where the head holds the module and length of array, and the
	 * tail holds a pointer to the next list.
	 */
	map_array = kmalloc(sizeof(*map_array) * (len + 2), GFP_KERNEL);
	if (!map_array) {
		pr_warn("Unable to allocate trace eval mapping\n");
		return;
	}

	mutex_lock(&trace_eval_mutex);

	if (!trace_eval_maps)
		trace_eval_maps = map_array;
	else {
		ptr = trace_eval_maps;
		for (;;) {
			ptr = trace_eval_jmp_to_tail(ptr);
			if (!ptr->tail.next)
				break;
			ptr = ptr->tail.next;

		}
		ptr->tail.next = map_array;
	}
	map_array->head.mod = mod;
	map_array->head.length = len;
	map_array++;

	for (map = start; (unsigned long)map < (unsigned long)stop; map++) {
		map_array->map = **map;
		map_array++;
	}
	memset(map_array, 0, sizeof(*map_array));

	mutex_unlock(&trace_eval_mutex);
}

Project: linux
File: trace.c

static inline void trace_access_lock_init(void)
{
}

Project: linux
File: trace.c

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->flags =
#ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
		(irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) |
#else
		TRACE_FLAG_IRQS_NOSUPPORT |
#endif
		((pc & NMI_MASK    ) ? TRACE_FLAG_NMI     : 0) |
		((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) |
		((pc & SOFTIRQ_OFFSET) ? TRACE_FLAG_SOFTIRQ : 0) |
		(tif_need_resched() ? TRACE_FLAG_NEED_RESCHED : 0) |
		(test_preempt_need_resched() ? TRACE_FLAG_PREEMPT_RESCHED : 0);
}

Project: linux
File: trace.c

static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
{
	struct trace_array *tr = iter->tr;
	struct trace_seq *s = &iter->seq;
	unsigned long sym_flags = (tr->trace_flags & TRACE_ITER_SYM_MASK);
	struct trace_entry *entry;
	struct trace_event *event;

	entry = iter->ent;

	test_cpu_buff_start(iter);

	event = ftrace_find_event(entry->type);

	if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) {
		if (iter->iter_flags & TRACE_FILE_LAT_FMT)
			trace_print_lat_context(iter);
		else
			trace_print_context(iter);
	}

	if (trace_seq_has_overflowed(s))
		return TRACE_TYPE_PARTIAL_LINE;

	if (event)
		return event->funcs->trace(iter, sym_flags, event);

	trace_seq_printf(s, "Unknown type %d\n", entry->type);

	return trace_handle_return(s);
}

Project: linux
File: trace.c

void tracing_iter_reset(struct trace_iterator *iter, int cpu)
{
	struct ring_buffer_event *event;
	struct ring_buffer_iter *buf_iter;
	unsigned long entries = 0;
	u64 ts;

	per_cpu_ptr(iter->trace_buffer->data, cpu)->skipped_entries = 0;

	buf_iter = trace_buffer_iter(iter, cpu);
	if (!buf_iter)
		return;

	ring_buffer_iter_reset(buf_iter);

	/*
	 * We could have the case with the max latency tracers
	 * that a reset never took place on a cpu. This is evident
	 * by the timestamp being before the start of the buffer.
	 */
	while ((event = ring_buffer_iter_peek(buf_iter, &ts))) {
		if (ts >= iter->trace_buffer->time_start)
			break;
		entries++;
		ring_buffer_read(buf_iter, NULL);
	}

	per_cpu_ptr(iter->trace_buffer->data, cpu)->skipped_entries = entries;
}

Project: linux
File: trace.c

void trace_event_buffer_commit(struct trace_event_buffer *fbuffer)
{
	if (static_key_false(&tracepoint_printk_key.key))
		output_printk(fbuffer);

	event_trigger_unlock_commit(fbuffer->trace_file, fbuffer->buffer,
				    fbuffer->event, fbuffer->entry,
				    fbuffer->flags, fbuffer->pc);
}

Project: linux
File: trace.c

static void *saved_cmdlines_start(struct seq_file *m, loff_t *pos)
{
	void *v;
	loff_t l = 0;

	preempt_disable();
	arch_spin_lock(&trace_cmdline_lock);

	v = &savedcmd->map_cmdline_to_pid[0];
	while (l <= *pos) {
		v = saved_cmdlines_next(m, v, &l);
		if (!v)
			return NULL;
	}

	return v;
}

Project: linux
File: trace.c

__update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
{
	struct trace_buffer *trace_buf = &tr->trace_buffer;
	struct trace_buffer *max_buf = &tr->max_buffer;
	struct trace_array_cpu *data = per_cpu_ptr(trace_buf->data, cpu);
	struct trace_array_cpu *max_data = per_cpu_ptr(max_buf->data, cpu);

	max_buf->cpu = cpu;
	max_buf->time_start = data->preempt_timestamp;

	max_data->saved_latency = tr->max_latency;
	max_data->critical_start = data->critical_start;
	max_data->critical_end = data->critical_end;

	memcpy(max_data->comm, tsk->comm, TASK_COMM_LEN);
	max_data->pid = tsk->pid;
	/*
	 * If tsk == current, then use current_uid(), as that does not use
	 * RCU. The irq tracer can be called out of RCU scope.
	 */
	if (tsk == current)
		max_data->uid = current_uid();
	else
		max_data->uid = task_uid(tsk);

	max_data->nice = tsk->static_prio - 20 - MAX_RT_PRIO;
	max_data->policy = tsk->policy;
	max_data->rt_priority = tsk->rt_priority;

	/* record this tasks comm */
	tracing_record_cmdline(tsk);
}

Project: linux
File: trace.c

static void init_trace_flags_index(struct trace_array *tr)
{
	int i;

	/* Used by the trace options files */
	for (i = 0; i < TRACE_FLAGS_MAX_SIZE; i++)
		tr->trace_flags_index[i] = i;
}

Project: linux
File: trace.c

static inline void ftrace_trace_stack(struct trace_array *tr,
				      struct ring_buffer *buffer,
				      unsigned long flags,
				      int skip, int pc, struct pt_regs *regs)
{
}

Project: linux
File: trace.c

trace_printk_seq(struct trace_seq *s)
{
	/* Probably should print a warning here. */
	if (s->seq.len >= TRACE_MAX_PRINT)
		s->seq.len = TRACE_MAX_PRINT;

	/*
	 * More paranoid code. Although the buffer size is set to
	 * PAGE_SIZE, and TRACE_MAX_PRINT is 1000, this is just
	 * an extra layer of protection.
	 */
	if (WARN_ON_ONCE(s->seq.len >= s->seq.size))
		s->seq.len = s->seq.size - 1;

	/* should be zero ended, but we are paranoid. */
	s->buffer[s->seq.len] = 0;

	printk(KERN_TRACE "%s", s->buffer);

	trace_seq_init(s);
}

Project: linux
File: trace.c

int trace_find_tgid(int pid)
{
	if (unlikely(!tgid_map || !pid || pid > PID_MAX_DEFAULT))
		return 0;

	return tgid_map[pid];
}

Project: linux
File: trace.c

int __init register_tracer(struct tracer *type)
{
	struct tracer *t;
	int ret = 0;

	if (!type->name) {
		pr_info("Tracer must have a name\n");
		return -1;
	}

	if (strlen(type->name) >= MAX_TRACER_SIZE) {
		pr_info("Tracer has a name longer than %d\n", MAX_TRACER_SIZE);
		return -1;
	}

	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("Tracer %s already registered\n",
				type->name);
			ret = -1;
			goto out;
		}
	}

	if (!type->set_flag)
		type->set_flag = &dummy_set_flag;
	if (!type->flags) {
		/*allocate a dummy tracer_flags*/
		type->flags = kmalloc(sizeof(*type->flags), GFP_KERNEL);
		if (!type->flags) {
			ret = -ENOMEM;
			goto out;
		}
		type->flags->val = 0;
		type->flags->opts = dummy_tracer_opt;
	} else
		if (!type->flags->opts)
			type->flags->opts = dummy_tracer_opt;

	/* store the tracer for __set_tracer_option */
	type->flags->trace = type;

	ret = run_tracer_selftest(type);
	if (ret < 0)
		goto out;

	type->next = trace_types;
	trace_types = type;
	add_tracer_options(&global_trace, type);

 out:
	tracing_selftest_running = false;
	mutex_unlock(&trace_types_lock);

	if (ret || !default_bootup_tracer)
		goto out_unlock;

	if (strncmp(default_bootup_tracer, type->name, MAX_TRACER_SIZE))
		goto out_unlock;

	printk(KERN_INFO "Starting tracer '%s'\n", type->name);
	/* Do we want this tracer to start on bootup? */
	tracing_set_tracer(&global_trace, type->name);
	default_bootup_tracer = NULL;

	apply_trace_boot_options();

	/* disable other selftests, since this will break it. */
	tracing_selftest_disabled = true;
#ifdef CONFIG_FTRACE_STARTUP_TEST
	printk(KERN_INFO "Disabling FTRACE selftests due to running tracer '%s'\n",
	       type->name);
#endif

 out_unlock:
	return ret;
}

Project: linux
File: trace.c

void trace_free_pid_list(struct trace_pid_list *pid_list)
{
	vfree(pid_list->pids);
	kfree(pid_list);
}

Project: linux
File: trace.c

print_trace_header(struct seq_file *m, struct trace_iterator *iter)
{
	unsigned long sym_flags = (global_trace.trace_flags & TRACE_ITER_SYM_MASK);
	struct trace_buffer *buf = iter->trace_buffer;
	struct trace_array_cpu *data = per_cpu_ptr(buf->data, buf->cpu);
	struct tracer *type = iter->trace;
	unsigned long entries;
	unsigned long total;
	const char *name = "preemption";

	name = type->name;

	get_total_entries(buf, &total, &entries);

	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,
		   buf->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,
		   from_kuid_munged(seq_user_ns(m), 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#\n");
	}

	seq_puts(m, "#\n");
}

Project: linux
File: trace.c

tracing_mark_write(struct file *filp, const char __user *ubuf,
					size_t cnt, loff_t *fpos)
{
	struct trace_array *tr = filp->private_data;
	struct ring_buffer_event *event;
	struct ring_buffer *buffer;
	struct print_entry *entry;
	unsigned long irq_flags;
	const char faulted[] = "<faulted>";
	ssize_t written;
	int size;
	int len;

/* Used in tracing_mark_raw_write() as well */
#define FAULTED_SIZE (sizeof(faulted) - 1) /* '\0' is already accounted for */

	if (tracing_disabled)
		return -EINVAL;

	if (!(tr->trace_flags & TRACE_ITER_MARKERS))
		return -EINVAL;

	if (cnt > TRACE_BUF_SIZE)
		cnt = TRACE_BUF_SIZE;

	BUILD_BUG_ON(TRACE_BUF_SIZE >= PAGE_SIZE);

	local_save_flags(irq_flags);
	size = sizeof(*entry) + cnt + 2; /* add '\0' and possible '\n' */

	/* If less than "<faulted>", then make sure we can still add that */
	if (cnt < FAULTED_SIZE)
		size += FAULTED_SIZE - cnt;

	buffer = tr->trace_buffer.buffer;
	event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, size,
					    irq_flags, preempt_count());
	if (unlikely(!event))
		/* Ring buffer disabled, return as if not open for write */
		return -EBADF;

	entry = ring_buffer_event_data(event);
	entry->ip = _THIS_IP_;

	len = __copy_from_user_inatomic(&entry->buf, ubuf, cnt);
	if (len) {
		memcpy(&entry->buf, faulted, FAULTED_SIZE);
		cnt = FAULTED_SIZE;
		written = -EFAULT;
	} else
		written = cnt;
	len = cnt;

	if (entry->buf[cnt - 1] != '\n') {
		entry->buf[cnt] = '\n';
		entry->buf[cnt + 1] = '\0';
	} else
		entry->buf[cnt] = '\0';

	__buffer_unlock_commit(buffer, event);

	if (written > 0)
		*fpos += written;

	return written;
}

Project: linux
File: trace.c

int tracing_open_generic(struct inode *inode, struct file *filp)
{
	if (tracing_disabled)
		return -ENODEV;

	filp->private_data = inode->i_private;
	return 0;
}

Project: linux
File: trace.c

static int tracing_set_tracer(struct trace_array *tr, const char *buf)
{
	struct tracer *t;
#ifdef CONFIG_TRACER_MAX_TRACE
	bool had_max_tr;
#endif
	int ret = 0;

	mutex_lock(&trace_types_lock);

	if (!ring_buffer_expanded) {
		ret = __tracing_resize_ring_buffer(tr, trace_buf_size,
						RING_BUFFER_ALL_CPUS);
		if (ret < 0)
			goto out;
		ret = 0;
	}

	for (t = trace_types; t; t = t->next) {
		if (strcmp(t->name, buf) == 0)
			break;
	}
	if (!t) {
		ret = -EINVAL;
		goto out;
	}
	if (t == tr->current_trace)
		goto out;

	/* Some tracers won't work on kernel command line */
	if (system_state < SYSTEM_RUNNING && t->noboot) {
		pr_warn("Tracer '%s' is not allowed on command line, ignored\n",
			t->name);
		goto out;
	}

	/* Some tracers are only allowed for the top level buffer */
	if (!trace_ok_for_array(t, tr)) {
		ret = -EINVAL;
		goto out;
	}

	/* If trace pipe files are being read, we can't change the tracer */
	if (tr->current_trace->ref) {
		ret = -EBUSY;
		goto out;
	}

	trace_branch_disable();

	tr->current_trace->enabled--;

	if (tr->current_trace->reset)
		tr->current_trace->reset(tr);

	/* Current trace needs to be nop_trace before synchronize_sched */
	tr->current_trace = &nop_trace;

#ifdef CONFIG_TRACER_MAX_TRACE
	had_max_tr = tr->allocated_snapshot;

	if (had_max_tr && !t->use_max_tr) {
		/*
		 * We need to make sure that the update_max_tr sees that
		 * current_trace changed to nop_trace to keep it from
		 * swapping the buffers after we resize it.
		 * The update_max_tr is called from interrupts disabled
		 * so a synchronized_sched() is sufficient.
		 */
		synchronize_sched();
		free_snapshot(tr);
	}
#endif

#ifdef CONFIG_TRACER_MAX_TRACE
	if (t->use_max_tr && !had_max_tr) {
		ret = alloc_snapshot(tr);
		if (ret < 0)
			goto out;
	}
#endif

	if (t->init) {
		ret = tracer_init(t, tr);
		if (ret)
			goto out;
	}

	tr->current_trace = t;
	tr->current_trace->enabled++;
	trace_branch_enable(tr);
 out:
	mutex_unlock(&trace_types_lock);

	return ret;
}

Project: linux
File: trace.c

static int trace_save_tgid(struct task_struct *tsk)
{
	/* treat recording of idle task as a success */
	if (!tsk->pid)
		return 1;

	if (unlikely(!tgid_map || tsk->pid > PID_MAX_DEFAULT))
		return 0;

	tgid_map[tsk->pid] = tsk->tgid;
	return 1;
}

Project: linux
File: trace.c

static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf,
				   size_t cnt, loff_t *fpos)
{
	struct seq_file *m = filp->private_data;
	struct trace_array *tr = m->private;
	char buf[64];
	const char *clockstr;
	int ret;

	if (cnt >= sizeof(buf))
		return -EINVAL;

	if (copy_from_user(buf, ubuf, cnt))
		return -EFAULT;

	buf[cnt] = 0;

	clockstr = strstrip(buf);

	ret = tracing_set_clock(tr, clockstr);
	if (ret)
		return ret;

	*fpos += cnt;

	return cnt;
}

Project: linux
File: trace.c

int tracing_is_enabled(void)
{
	/*
	 * For quick access (irqsoff uses this in fast path), just
	 * return the mirror variable of the state of the ring buffer.
	 * It's a little racy, but we don't really care.
	 */
	smp_rmb();
	return !global_trace.buffer_disabled;
}

Project: linux
File: trace.c

tracing_entries_write(struct file *filp, const char __user *ubuf,
		      size_t cnt, loff_t *ppos)
{
	struct inode *inode = file_inode(filp);
	struct trace_array *tr = inode->i_private;
	unsigned long val;
	int ret;

	ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
	if (ret)
		return ret;

	/* must have at least 1 entry */
	if (!val)
		return -EINVAL;

	/* value is in KB */
	val <<= 10;
	ret = tracing_resize_ring_buffer(tr, val, tracing_get_cpu(inode));
	if (ret < 0)
		return ret;

	*ppos += cnt;

	return cnt;
}

Project: linux
File: trace.c

trace_buffer_lock_reserve(struct ring_buffer *buffer,
			  int type,
			  unsigned long len,
			  unsigned long flags, int pc)
{
	return __trace_buffer_lock_reserve(buffer, type, len, flags, pc);
}

Project: linux
File: trace.c

get_tracer_for_array(struct trace_array *tr, struct tracer *t)
{
	while (t && !trace_ok_for_array(t, tr))
		t = t->next;

	return t;
}

Project: linux
File: trace.c

rm_ftrace_export(struct trace_export **list, struct trace_export *export)
{
	int ret;

	ret = rm_trace_export(list, export);
	if (*list == NULL)
		ftrace_exports_disable();

	return ret;
}

Project: linux
File: trace.c

rb_simple_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 = tracer_tracing_is_on(tr);
	r = sprintf(buf, "%d\n", r);

	return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
}

Project: linux
File: trace.c

ftrace_count_snapshot(unsigned long ip, unsigned long parent_ip,
		      struct trace_array *tr, struct ftrace_probe_ops *ops,
		      void *data)
{
	struct ftrace_func_mapper *mapper = data;
	long *count = NULL;

	if (mapper)
		count = (long *)ftrace_func_mapper_find_ip(mapper, ip);

	if (count) {

		if (*count <= 0)
			return;

		(*count)--;
	}

	tracing_snapshot_instance(tr);
}

Project: linux
File: trace.c

static void __init apply_trace_boot_options(void)
{
	char *buf = trace_boot_options_buf;
	char *option;

	while (true) {
		option = strsep(&buf, ",");

		if (!option)
			break;

		if (*option)
			trace_set_options(&global_trace, option);

		/* Put back the comma to allow this to be called again */
		if (buf)
			*(buf - 1) = ',';
	}
}

Project: linux
File: trace.c

ftrace_snapshot_print(struct seq_file *m, unsigned long ip,
		      struct ftrace_probe_ops *ops, void *data)
{
	struct ftrace_func_mapper *mapper = data;
	long *count = NULL;

	seq_printf(m, "%ps:", (void *)ip);

	seq_puts(m, "snapshot");

	if (mapper)
		count = (long *)ftrace_func_mapper_find_ip(mapper, ip);

	if (count)
		seq_printf(m, ":count=%ld\n", *count);
	else
		seq_puts(m, ":unlimited\n");

	return 0;
}

Project: linux
File: trace.c

static void put_trace_buf(void)
{
	/* Don't let the decrement of nesting leak before this */
	barrier();
	this_cpu_dec(trace_percpu_buffer->nesting);
}

Project: linux
File: trace.c

static int __init set_tracepoint_printk(char *str)
{
	if ((strcmp(str, "=0") != 0 && strcmp(str, "=off") != 0))
		tracepoint_printk = 1;
	return 1;
}

Project: linux
File: trace.c

static struct vfsmount *trace_automount(struct dentry *mntpt, void *ingore)
{
	struct vfsmount *mnt;
	struct file_system_type *type;

	/*
	 * To maintain backward compatibility for tools that mount
	 * debugfs to get to the tracing facility, tracefs is automatically
	 * mounted to the debugfs/tracing directory.
	 */
	type = get_fs_type("tracefs");
	if (!type)
		return NULL;
	mnt = vfs_submount(mntpt, type, "tracefs", NULL);
	put_filesystem(type);
	if (IS_ERR(mnt))
		return NULL;
	mntget(mnt);

	return mnt;
}

Project: linux
File: trace.c

static int run_tracer_selftest(struct tracer *type)
{
	struct trace_array *tr = &global_trace;
	struct tracer *saved_tracer = tr->current_trace;
	int ret;

	if (!type->selftest || tracing_selftest_disabled)
		return 0;

	/*
	 * If a tracer registers early in boot up (before scheduling is
	 * initialized and such), then do not run its selftests yet.
	 * Instead, run it a little later in the boot process.
	 */
	if (!selftests_can_run)
		return save_selftest(type);

	/*
	 * 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.
	 */
	tracing_reset_online_cpus(&tr->trace_buffer);

	tr->current_trace = type;

#ifdef CONFIG_TRACER_MAX_TRACE
	if (type->use_max_tr) {
		/* If we expanded the buffers, make sure the max is expanded too */
		if (ring_buffer_expanded)
			ring_buffer_resize(tr->max_buffer.buffer, trace_buf_size,
					   RING_BUFFER_ALL_CPUS);
		tr->allocated_snapshot = true;
	}
#endif

	/* 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 */
	tr->current_trace = saved_tracer;
	if (ret) {
		printk(KERN_CONT "FAILED!\n");
		/* Add the warning after printing 'FAILED' */
		WARN_ON(1);
		return -1;
	}
	/* Only reset on passing, to avoid touching corrupted buffers */
	tracing_reset_online_cpus(&tr->trace_buffer);

#ifdef CONFIG_TRACER_MAX_TRACE
	if (type->use_max_tr) {
		tr->allocated_snapshot = false;

		/* Shrink the max buffer again */
		if (ring_buffer_expanded)
			ring_buffer_resize(tr->max_buffer.buffer, 1,
					   RING_BUFFER_ALL_CPUS);
	}
#endif

	printk(KERN_CONT "PASSED\n");
	return 0;
}

Project: linux
File: trace.c

static int alloc_percpu_trace_buffer(void)
{
	struct trace_buffer_struct *buffers;

	buffers = alloc_percpu(struct trace_buffer_struct);
	if (WARN(!buffers, "Could not allocate percpu trace_printk buffer"))
		return -ENOMEM;

	trace_percpu_buffer = buffers;
	return 0;
}

Project: linux
File: trace.c

static int tracing_buffers_release(struct inode *inode, struct file *file)
{
	struct ftrace_buffer_info *info = file->private_data;
	struct trace_iterator *iter = &info->iter;

	mutex_lock(&trace_types_lock);

	iter->tr->current_trace->ref--;

	__trace_array_put(iter->tr);

	if (info->spare)
		ring_buffer_free_read_page(iter->trace_buffer->buffer,
					   info->spare_cpu, info->spare);
	kfree(info);

	mutex_unlock(&trace_types_lock);

	return 0;
}

Project: linux
File: trace.c

static int tracing_trace_options_open(struct inode *inode, struct file *file)
{
	struct trace_array *tr = inode->i_private;
	int ret;

	if (tracing_disabled)
		return -ENODEV;

	if (trace_array_get(tr) < 0)
		return -ENODEV;

	ret = single_open(file, tracing_trace_options_show, inode->i_private);
	if (ret < 0)
		trace_array_put(tr);

	return ret;
}

Project: linux
File: trace.c

static void tracing_stop_tr(struct trace_array *tr)
{
	struct ring_buffer *buffer;
	unsigned long flags;

	/* If global, we need to also stop the max tracer */
	if (tr->flags & TRACE_ARRAY_FL_GLOBAL)
		return tracing_stop();

	raw_spin_lock_irqsave(&tr->start_lock, flags);
	if (tr->stop_count++)
		goto out;

	buffer = tr->trace_buffer.buffer;
	if (buffer)
		ring_buffer_record_disable(buffer);

 out:
	raw_spin_unlock_irqrestore(&tr->start_lock, flags);
}

Project: linux
File: trace.c

static int __init stop_trace_on_warning(char *str)
{
	if ((strcmp(str, "=0") != 0 && strcmp(str, "=off") != 0))
		__disable_trace_on_warning = 1;
	return 1;
}

Project: linux
File: trace.c

static int __init set_trace_boot_clock(char *str)
{
	strlcpy(trace_boot_clock_buf, str, MAX_TRACER_SIZE);
	trace_boot_clock = trace_boot_clock_buf;
	return 0;
}

Project: linux
File: trace.c

static void free_saved_cmdlines_buffer(struct saved_cmdlines_buffer *s)
{
	kfree(s->saved_cmdlines);
	kfree(s->map_cmdline_to_pid);
	kfree(s);
}

Project: linux
File: trace.c

tracing_thresh_read(struct file *filp, char __user *ubuf,
		    size_t cnt, loff_t *ppos)
{
	return tracing_nsecs_read(&tracing_thresh, ubuf, cnt, ppos);
}

Project: linux
File: trace.c

void tracing_record_tgid(struct task_struct *task)
{
	tracing_record_taskinfo(task, TRACE_RECORD_TGID);
}

Project: linux
File: trace.c

static enum print_line_t print_bin_fmt(struct trace_iterator *iter)
{
	struct trace_array *tr = iter->tr;
	struct trace_seq *s = &iter->seq;
	struct trace_entry *entry;
	struct trace_event *event;

	entry = iter->ent;

	if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) {
		SEQ_PUT_FIELD(s, entry->pid);
		SEQ_PUT_FIELD(s, iter->cpu);
		SEQ_PUT_FIELD(s, iter->ts);
		if (trace_seq_has_overflowed(s))
			return TRACE_TYPE_PARTIAL_LINE;
	}

	event = ftrace_find_event(entry->type);
	return event ? event->funcs->binary(iter, 0, event) :
		TRACE_TYPE_HANDLED;
}

Project: linux
File: trace.c

static inline int run_tracer_selftest(struct tracer *type)
{
	return 0;
}

Project: linux
File: trace.c

int trace_vbprintk(unsigned long ip, const char *fmt, va_list args)
{
	struct trace_event_call *call = &event_bprint;
	struct ring_buffer_event *event;
	struct ring_buffer *buffer;
	struct trace_array *tr = &global_trace;
	struct bprint_entry *entry;
	unsigned long flags;
	char *tbuffer;
	int len = 0, size, pc;

	if (unlikely(tracing_selftest_running || tracing_disabled))
		return 0;

	/* Don't pollute graph traces with trace_vprintk internals */
	pause_graph_tracing();

	pc = preempt_count();
	preempt_disable_notrace();

	tbuffer = get_trace_buf();
	if (!tbuffer) {
		len = 0;
		goto out_nobuffer;
	}

	len = vbin_printf((u32 *)tbuffer, TRACE_BUF_SIZE/sizeof(int), fmt, args);

	if (len > TRACE_BUF_SIZE/sizeof(int) || len < 0)
		goto out;

	local_save_flags(flags);
	size = sizeof(*entry) + sizeof(u32) * len;
	buffer = tr->trace_buffer.buffer;
	event = __trace_buffer_lock_reserve(buffer, TRACE_BPRINT, size,
					    flags, pc);
	if (!event)
		goto out;
	entry = ring_buffer_event_data(event);
	entry->ip			= ip;
	entry->fmt			= fmt;

	memcpy(entry->buf, tbuffer, sizeof(u32) * len);
	if (!call_filter_check_discard(call, entry, buffer, event)) {
		__buffer_unlock_commit(buffer, event);
		ftrace_trace_stack(tr, buffer, flags, 6, pc, NULL);
	}

out:
	put_trace_buf();

out_nobuffer:
	preempt_enable_notrace();
	unpause_graph_tracing();

	return len;
}

Project: linux
File: trace.c

static int __tracing_resize_ring_buffer(struct trace_array *tr,
					unsigned long size, int cpu)
{
	int ret;

	/*
	 * If kernel or user changes the size of the ring buffer
	 * we use the size that was given, and we can forget about
	 * expanding it later.
	 */
	ring_buffer_expanded = true;

	/* May be called before buffers are initialized */
	if (!tr->trace_buffer.buffer)
		return 0;

	ret = ring_buffer_resize(tr->trace_buffer.buffer, size, cpu);
	if (ret < 0)
		return ret;

#ifdef CONFIG_TRACER_MAX_TRACE
	if (!(tr->flags & TRACE_ARRAY_FL_GLOBAL) ||
	    !tr->current_trace->use_max_tr)
		goto out;

	ret = ring_buffer_resize(tr->max_buffer.buffer, size, cpu);
	if (ret < 0) {
		int r = resize_buffer_duplicate_size(&tr->trace_buffer,
						     &tr->trace_buffer, cpu);
		if (r < 0) {
			/*
			 * AARGH! We are left with different
			 * size max buffer!!!!
			 * The max buffer is our "snapshot" buffer.
			 * When a tracer needs a snapshot (one of the
			 * latency tracers), it swaps the max buffer
			 * with the saved snap shot. We succeeded to
			 * update the size of the main buffer, but failed to
			 * update the size of the max buffer. But when we tried
			 * to reset the main buffer to the original size, we
			 * failed there too. This is very unlikely to
			 * happen, but if it does, warn and kill all
			 * tracing.
			 */
			WARN_ON(1);
			tracing_disabled = 1;
		}
		return ret;
	}

	if (cpu == RING_BUFFER_ALL_CPUS)
		set_buffer_entries(&tr->max_buffer, size);
	else
		per_cpu_ptr(tr->max_buffer.data, cpu)->entries = size;

 out:
#endif /* CONFIG_TRACER_MAX_TRACE */

	if (cpu == RING_BUFFER_ALL_CPUS)
		set_buffer_entries(&tr->trace_buffer, size);
	else
		per_cpu_ptr(tr->trace_buffer.data, cpu)->entries = size;

	return ret;
}

Project: linux
File: trace.c

tracing_trace_options_write(struct file *filp, const char __user *ubuf,
			size_t cnt, loff_t *ppos)
{
	struct seq_file *m = filp->private_data;
	struct trace_array *tr = m->private;
	char buf[64];
	int ret;

	if (cnt >= sizeof(buf))
		return -EINVAL;

	if (copy_from_user(buf, ubuf, cnt))
		return -EFAULT;

	buf[cnt] = 0;

	ret = trace_set_options(tr, buf);
	if (ret < 0)
		return ret;

	*ppos += cnt;

	return cnt;
}

Project: linux
File: trace.c

static int s_show(struct seq_file *m, void *v)
{
	struct trace_iterator *iter = v;
	int ret;

	if (iter->ent == NULL) {
		if (iter->tr) {
			seq_printf(m, "# tracer: %s\n", iter->trace->name);
			seq_puts(m, "#\n");
			test_ftrace_alive(m);
		}
		if (iter->snapshot && trace_empty(iter))
			print_snapshot_help(m, iter);
		else if (iter->trace && iter->trace->print_header)
			iter->trace->print_header(m);
		else
			trace_default_header(m);

	} else if (iter->leftover) {
		/*
		 * If we filled the seq_file buffer earlier, we
		 * want to just show it now.
		 */
		ret = trace_print_seq(m, &iter->seq);

		/* ret should this time be zero, but you never know */
		iter->leftover = ret;

	} else {
		print_trace_line(iter);
		ret = trace_print_seq(m, &iter->seq);
		/*
		 * If we overflow the seq_file buffer, then it will
		 * ask us for this data again at start up.
		 * Use that instead.
		 *  ret is 0 if seq_file write succeeded.
		 *        -1 otherwise.
		 */
		iter->leftover = ret;
	}

	return 0;
}

Project: linux
File: trace.c

tracing_max_lat_read(struct file *filp, char __user *ubuf,
		     size_t cnt, loff_t *ppos)
{
	return tracing_nsecs_read(filp->private_data, ubuf, cnt, ppos);
}

Project: linux
File: trace.c

int trace_array_get(struct trace_array *this_tr)
{
	struct trace_array *tr;
	int ret = -ENODEV;

	mutex_lock(&trace_types_lock);
	list_for_each_entry(tr, &ftrace_trace_arrays, list) {
		if (tr == this_tr) {
			tr->ref++;
			ret = 0;
			break;
		}
	}
	mutex_unlock(&trace_types_lock);

	return ret;
}

Project: linux
File: trace.c

create_trace_option_file(struct trace_array *tr,
			 struct trace_option_dentry *topt,
			 struct tracer_flags *flags,
			 struct tracer_opt *opt)
{
	struct dentry *t_options;

	t_options = trace_options_init_dentry(tr);
	if (!t_options)
		return;

	topt->flags = flags;
	topt->opt = opt;
	topt->tr = tr;

	topt->entry = trace_create_file(opt->name, 0644, t_options, topt,
				    &trace_options_fops);

}

Project: linux
File: trace.c

trace_find_filtered_pid(struct trace_pid_list *filtered_pids, pid_t search_pid)
{
	/*
	 * If pid_max changed after filtered_pids was created, we
	 * by default ignore all pids greater than the previous pid_max.
	 */
	if (search_pid >= filtered_pids->pid_max)
		return false;

	return test_bit(search_pid, filtered_pids->pids);
}

Project: linux
File: trace.c

void tracing_snapshot_alloc(void)
{
	int ret;

	ret = tracing_alloc_snapshot();
	if (ret < 0)
		return;

	tracing_snapshot();
}

Project: linux
File: trace.c

static int saved_cmdlines_show(struct seq_file *m, void *v)
{
	char buf[TASK_COMM_LEN];
	unsigned int *pid = v;

	__trace_find_cmdline(*pid, buf);
	seq_printf(m, "%d %s\n", *pid, buf);
	return 0;
}

Project: linux
File: trace.c

static int wait_on_pipe(struct trace_iterator *iter, bool full)
{
	/* Iterators are static, they should be filled or empty */
	if (trace_buffer_iter(iter, iter->cpu_file))
		return 0;

	return ring_buffer_wait(iter->trace_buffer->buffer, iter->cpu_file,
				full);
}

Project: linux
File: trace.c

trace_eval_jmp_to_tail(union trace_eval_map_item *ptr)
{
	/* Return tail of array given the head */
	return ptr + ptr->head.length + 1;
}

Project: linux
File: trace.c

static int tracing_open_pipe(struct inode *inode, struct file *filp)
{
	struct trace_array *tr = inode->i_private;
	struct trace_iterator *iter;
	int ret = 0;

	if (tracing_disabled)
		return -ENODEV;

	if (trace_array_get(tr) < 0)
		return -ENODEV;

	mutex_lock(&trace_types_lock);

	/* create a buffer to store the information to pass to userspace */
	iter = kzalloc(sizeof(*iter), GFP_KERNEL);
	if (!iter) {
		ret = -ENOMEM;
		__trace_array_put(tr);
		goto out;
	}

	trace_seq_init(&iter->seq);
	iter->trace = tr->current_trace;

	if (!alloc_cpumask_var(&iter->started, GFP_KERNEL)) {
		ret = -ENOMEM;
		goto fail;
	}

	/* trace pipe does not show start of buffer */
	cpumask_setall(iter->started);

	if (tr->trace_flags & TRACE_ITER_LATENCY_FMT)
		iter->iter_flags |= TRACE_FILE_LAT_FMT;

	/* Output in nanoseconds only if we are using a clock in nanoseconds. */
	if (trace_clocks[tr->clock_id].in_ns)
		iter->iter_flags |= TRACE_FILE_TIME_IN_NS;

	iter->tr = tr;
	iter->trace_buffer = &tr->trace_buffer;
	iter->cpu_file = tracing_get_cpu(inode);
	mutex_init(&iter->mutex);
	filp->private_data = iter;

	if (iter->trace->pipe_open)
		iter->trace->pipe_open(iter);

	nonseekable_open(inode, filp);

	tr->current_trace->ref++;
out:
	mutex_unlock(&trace_types_lock);
	return ret;

fail:
	kfree(iter->trace);
	kfree(iter);
	__trace_array_put(tr);
	mutex_unlock(&trace_types_lock);
	return ret;
}

Project: linux
File: trace.c

trace_buffer_unlock_commit_nostack(struct ring_buffer *buffer,
				   struct ring_buffer_event *event)
{
	__buffer_unlock_commit(buffer, event);
}

Project: linux
File: trace.c

static int trace_create_savedcmd(void)
{
	int ret;

	savedcmd = kmalloc(sizeof(*savedcmd), GFP_KERNEL);
	if (!savedcmd)
		return -ENOMEM;

	ret = allocate_cmdlines_buffer(SAVED_CMDLINES_DEFAULT, savedcmd);
	if (ret < 0) {
		kfree(savedcmd);
		savedcmd = NULL;
		return -ENOMEM;
	}

	return 0;
}

Project: linux
File: trace.c

static int tracing_trace_options_show(struct seq_file *m, void *v)
{
	struct tracer_opt *trace_opts;
	struct trace_array *tr = m->private;
	u32 tracer_flags;
	int i;

	mutex_lock(&trace_types_lock);
	tracer_flags = tr->current_trace->flags->val;
	trace_opts = tr->current_trace->flags->opts;

	for (i = 0; trace_options[i]; i++) {
		if (tr->trace_flags & (1 << i))
			seq_printf(m, "%s\n", trace_options[i]);
		else
			seq_printf(m, "no%s\n", trace_options[i]);
	}

	for (i = 0; trace_opts[i].name; i++) {
		if (tracer_flags & trace_opts[i].bit)
			seq_printf(m, "%s\n", trace_opts[i].name);
		else
			seq_printf(m, "no%s\n", trace_opts[i].name);
	}
	mutex_unlock(&trace_types_lock);

	return 0;
}

Project: linux
File: trace.c

tracing_cpumask_read(struct file *filp, char __user *ubuf,
		     size_t count, loff_t *ppos)
{
	struct trace_array *tr = file_inode(filp)->i_private;
	char *mask_str;
	int len;

	len = snprintf(NULL, 0, "%*pb\n",
		       cpumask_pr_args(tr->tracing_cpumask)) + 1;
	mask_str = kmalloc(len, GFP_KERNEL);
	if (!mask_str)
		return -ENOMEM;

	len = snprintf(mask_str, len, "%*pb\n",
		       cpumask_pr_args(tr->tracing_cpumask));
	if (len >= count) {
		count = -EINVAL;
		goto out_err;
	}
	count = simple_read_from_buffer(ubuf, count, ppos, mask_str, len);

out_err:
	kfree(mask_str);

	return count;
}

Project: linux
File: trace.c

tracing_entries_read(struct file *filp, char __user *ubuf,
		     size_t cnt, loff_t *ppos)
{
	struct inode *inode = file_inode(filp);
	struct trace_array *tr = inode->i_private;
	int cpu = tracing_get_cpu(inode);
	char buf[64];
	int r = 0;
	ssize_t ret;

	mutex_lock(&trace_types_lock);

	if (cpu == RING_BUFFER_ALL_CPUS) {
		int cpu, buf_size_same;
		unsigned long size;

		size = 0;
		buf_size_same = 1;
		/* check if all cpu sizes are same */
		for_each_tracing_cpu(cpu) {
			/* fill in the size from first enabled cpu */
			if (size == 0)
				size = per_cpu_ptr(tr->trace_buffer.data, cpu)->entries;
			if (size != per_cpu_ptr(tr->trace_buffer.data, cpu)->entries) {
				buf_size_same = 0;
				break;
			}
		}

		if (buf_size_same) {
			if (!ring_buffer_expanded)
				r = sprintf(buf, "%lu (expanded: %lu)\n",
					    size >> 10,
					    trace_buf_size >> 10);
			else
				r = sprintf(buf, "%lu\n", size >> 10);
		} else
			r = sprintf(buf, "X\n");
	} else
		r = sprintf(buf, "%lu\n", per_cpu_ptr(tr->trace_buffer.data, cpu)->entries >> 10);

	mutex_unlock(&trace_types_lock);

	ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
	return ret;
}

Project: linux
File: trace.c

create_trace_option_core_file(struct trace_array *tr,
			      const char *option, long index)
{
	struct dentry *t_options;

	t_options = trace_options_init_dentry(tr);
	if (!t_options)
		return NULL;

	return trace_create_file(option, 0644, t_options,
				 (void *)&tr->trace_flags_index[index],
				 &trace_options_core_fops);
}

Project: linux
File: trace.c

static inline void trace_access_unlock(int cpu)
{
	if (cpu == RING_BUFFER_ALL_CPUS) {
		up_write(&all_cpu_access_lock);
	} else {
		mutex_unlock(&per_cpu(cpu_access_lock, cpu));
		up_read(&all_cpu_access_lock);
	}
}

Project: linux
File: trace.c

tracing_init_tracefs_percpu(struct trace_array *tr, long cpu)
{
	struct dentry *d_percpu = tracing_dentry_percpu(tr, cpu);
	struct dentry *d_cpu;
	char cpu_dir[30]; /* 30 characters should be more than enough */

	if (!d_percpu)
		return;

	snprintf(cpu_dir, 30, "cpu%ld", cpu);
	d_cpu = tracefs_create_dir(cpu_dir, d_percpu);
	if (!d_cpu) {
		pr_warn("Could not create tracefs '%s' entry\n", cpu_dir);
		return;
	}

	/* per cpu trace_pipe */
	trace_create_cpu_file("trace_pipe", 0444, d_cpu,
				tr, cpu, &tracing_pipe_fops);

	/* per cpu trace */
	trace_create_cpu_file("trace", 0644, d_cpu,
				tr, cpu, &tracing_fops);

	trace_create_cpu_file("trace_pipe_raw", 0444, d_cpu,
				tr, cpu, &tracing_buffers_fops);

	trace_create_cpu_file("stats", 0444, d_cpu,
				tr, cpu, &tracing_stats_fops);

	trace_create_cpu_file("buffer_size_kb", 0444, d_cpu,
				tr, cpu, &tracing_entries_fops);

#ifdef CONFIG_TRACER_SNAPSHOT
	trace_create_cpu_file("snapshot", 0644, d_cpu,
				tr, cpu, &snapshot_fops);

	trace_create_cpu_file("snapshot_raw", 0444, d_cpu,
				tr, cpu, &snapshot_raw_fops);
#endif
}

Project: linux
File: trace.c

tracing_poll_pipe(struct file *filp, poll_table *poll_table)
{
	struct trace_iterator *iter = filp->private_data;

	return trace_poll(iter, filp, poll_table);
}

Project: linux
File: trace.c

trace_create_cpu_file(const char *name, umode_t mode, struct dentry *parent,
		      void *data, long cpu, const struct file_operations *fops)
{
	struct dentry *ret = trace_create_file(name, mode, parent, data, fops);

	if (ret) /* See tracing_get_cpu() */
		d_inode(ret)->i_cdev = (void *)(cpu + 1);
	return ret;
}

Project: linux
File: trace.c

tracing_nsecs_write(unsigned long *ptr, const char __user *ubuf,
		    size_t cnt, loff_t *ppos)
{
	unsigned long val;
	int ret;

	ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
	if (ret)
		return ret;

	*ptr = val * 1000;

	return cnt;
}

Project: linux
File: trace.c

static void tracing_snapshot_instance(struct trace_array *tr)
{
	struct tracer *tracer = tr->current_trace;
	unsigned long flags;

	if (in_nmi()) {
		internal_trace_puts("*** SNAPSHOT CALLED FROM NMI CONTEXT ***\n");
		internal_trace_puts("*** snapshot is being ignored        ***\n");
		return;
	}

	if (!tr->allocated_snapshot) {
		internal_trace_puts("*** SNAPSHOT NOT ALLOCATED ***\n");
		internal_trace_puts("*** stopping trace here!   ***\n");
		tracing_off();
		return;
	}

	/* Note, snapshot can not be used when the tracer uses it */
	if (tracer->use_max_tr) {
		internal_trace_puts("*** LATENCY TRACER ACTIVE ***\n");
		internal_trace_puts("*** Can not use snapshot (sorry) ***\n");
		return;
	}

	local_irq_save(flags);
	update_max_tr(tr, current, smp_processor_id());
	local_irq_restore(flags);
}

Project: linux
File: trace.c

static __init int tracer_init_tracefs(void)
{
	struct dentry *d_tracer;

	trace_access_lock_init();

	d_tracer = tracing_init_dentry();
	if (IS_ERR(d_tracer))
		return 0;

	init_tracer_tracefs(&global_trace, d_tracer);
	ftrace_init_tracefs_toplevel(&global_trace, d_tracer);

	trace_create_file("tracing_thresh", 0644, d_tracer,
			&global_trace, &tracing_thresh_fops);

	trace_create_file("README", 0444, d_tracer,
			NULL, &tracing_readme_fops);

	trace_create_file("saved_cmdlines", 0444, d_tracer,
			NULL, &tracing_saved_cmdlines_fops);

	trace_create_file("saved_cmdlines_size", 0644, d_tracer,
			  NULL, &tracing_saved_cmdlines_size_fops);

	trace_create_file("saved_tgids", 0444, d_tracer,
			NULL, &tracing_saved_tgids_fops);

	trace_eval_init();

	trace_create_eval_file(d_tracer);

#ifdef CONFIG_MODULES
	register_module_notifier(&trace_module_nb);
#endif

#ifdef CONFIG_DYNAMIC_FTRACE
	trace_create_file("dyn_ftrace_total_info", 0444, d_tracer,
			&ftrace_update_tot_cnt, &tracing_dyn_info_fops);
#endif

	create_trace_instances(d_tracer);

	update_tracer_options(&global_trace);

	return 0;
}

Project: linux
File: trace.c

static u64 buffer_ftrace_now(struct trace_buffer *buf, int cpu)
{
	u64 ts;

	/* Early boot up does not have a buffer yet */
	if (!buf->buffer)
		return trace_clock_local();

	ts = ring_buffer_time_stamp(buf->buffer, cpu);
	ring_buffer_normalize_time_stamp(buf->buffer, cpu, &ts);

	return ts;
}

Project: linux
File: trace.c

update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
{
	struct ring_buffer *buf;

	if (tr->stop_count)
		return;

	WARN_ON_ONCE(!irqs_disabled());

	if (!tr->allocated_snapshot) {
		/* Only the nop tracer should hit this when disabling */
		WARN_ON_ONCE(tr->current_trace != &nop_trace);
		return;
	}

	arch_spin_lock(&tr->max_lock);

	buf = tr->trace_buffer.buffer;
	tr->trace_buffer.buffer = tr->max_buffer.buffer;
	tr->max_buffer.buffer = buf;

	__update_max_tr(tr, tsk, cpu);
	arch_spin_unlock(&tr->max_lock);
}

Project: linux
File: trace.c

static void trace_printk_start_stop_comm(int enabled)
{
	if (!buffers_allocated)
		return;

	if (enabled)
		tracing_start_cmdline_record();
	else
		tracing_stop_cmdline_record();
}

Project: linux
File: trace.c

static void tracing_set_nop(struct trace_array *tr)
{
	if (tr->current_trace == &nop_trace)
		return;
	
	tr->current_trace->enabled--;

	if (tr->current_trace->reset)
		tr->current_trace->reset(tr);

	tr->current_trace = &nop_trace;
}

Project: linux
File: trace.c

tracing_set_trace_read(struct file *filp, char __user *ubuf,
		       size_t cnt, loff_t *ppos)
{
	struct trace_array *tr = filp->private_data;
	char buf[MAX_TRACER_SIZE+2];
	int r;

	mutex_lock(&trace_types_lock);
	r = sprintf(buf, "%s\n", tr->current_trace->name);
	mutex_unlock(&trace_types_lock);

	return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
}

Project: linux
File: trace.c

static inline void trace_insert_eval_map_file(struct module *mod,
			      struct trace_eval_map **start, int len) { }

Project: linux
File: trace.c

static void free_trace_buffers(struct trace_array *tr)
{
	if (!tr)
		return;

	free_trace_buffer(&tr->trace_buffer);

#ifdef CONFIG_TRACER_MAX_TRACE
	free_trace_buffer(&tr->max_buffer);
#endif
}

Project: linux
File: trace.c

static int __set_tracer_option(struct trace_array *tr,
			       struct tracer_flags *tracer_flags,
			       struct tracer_opt *opts, int neg)
{
	struct tracer *trace = tracer_flags->trace;
	int ret;

	ret = trace->set_flag(tr, tracer_flags->val, opts->bit, !neg);
	if (ret)
		return ret;

	if (neg)
		tracer_flags->val &= ~opts->bit;
	else
		tracer_flags->val |= opts->bit;
	return 0;
}

Project: linux
File: trace.c

void tracing_reset_all_online_cpus(void)
{
	struct trace_array *tr;

	list_for_each_entry(tr, &ftrace_trace_arrays, list) {
		if (!tr->clear_trace)
			continue;
		tr->clear_trace = false;
		tracing_reset_online_cpus(&tr->trace_buffer);
#ifdef CONFIG_TRACER_MAX_TRACE
		tracing_reset_online_cpus(&tr->max_buffer);
#endif
	}
}

Project: linux
File: trace.c

static void saved_tgids_stop(struct seq_file *m, void *v)
{
}

Project: linux
File: trace.c

static int tracing_clock_show(struct seq_file *m, void *v)
{
	struct trace_array *tr = m->private;
	int i;

	for (i = 0; i < ARRAY_SIZE(trace_clocks); i++)
		seq_printf(m,
			"%s%s%s%s", i ? " " : "",
			i == tr->clock_id ? "[" : "", trace_clocks[i].name,
			i == tr->clock_id ? "]" : "");
	seq_putc(m, '\n');

	return 0;
}

Project: linux
File: trace.c

int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
	size_t cnt, loff_t *ppos)
{
	char ch;
	size_t read = 0;
	ssize_t ret;

	if (!*ppos)
		trace_parser_clear(parser);

	ret = get_user(ch, ubuf++);
	if (ret)
		goto out;

	read++;
	cnt--;

	/*
	 * The parser is not finished with the last write,
	 * continue reading the user input without skipping spaces.
	 */
	if (!parser->cont) {
		/* skip white space */
		while (cnt && isspace(ch)) {
			ret = get_user(ch, ubuf++);
			if (ret)
				goto out;
			read++;
			cnt--;
		}

		/* only spaces were written */
		if (isspace(ch)) {
			*ppos += read;
			ret = read;
			goto out;
		}

		parser->idx = 0;
	}

	/* read the non-space input */
	while (cnt && !isspace(ch)) {
		if (parser->idx < parser->size - 1)
			parser->buffer[parser->idx++] = ch;
		else {
			ret = -EINVAL;
			goto out;
		}
		ret = get_user(ch, ubuf++);
		if (ret)
			goto out;
		read++;
		cnt--;
	}

	/* We either got finished input or we have to wait for another call. */
	if (isspace(ch)) {
		parser->buffer[parser->idx] = 0;
		parser->cont = false;
	} else if (parser->idx < parser->size - 1) {
		parser->cont = true;
		parser->buffer[parser->idx++] = ch;
	} else {
		ret = -EINVAL;
		goto out;
	}

	*ppos += read;
	ret = read;

out:
	return ret;
}

Project: linux
File: trace.c

static int tracing_saved_tgids_open(struct inode *inode, struct file *filp)
{
	if (tracing_disabled)
		return -ENODEV;

	return seq_open(filp, &tracing_saved_tgids_seq_ops);
}

Project: linux
File: trace.c

tracing_total_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, cpu;
	unsigned long size = 0, expanded_size = 0;

	mutex_lock(&trace_types_lock);
	for_each_tracing_cpu(cpu) {
		size += per_cpu_ptr(tr->trace_buffer.data, cpu)->entries >> 10;
		if (!ring_buffer_expanded)
			expanded_size += trace_buf_size >> 10;
	}
	if (ring_buffer_expanded)
		r = sprintf(buf, "%lu\n", size);
	else
		r = sprintf(buf, "%lu (expanded: %lu)\n", size, expanded_size);
	mutex_unlock(&trace_types_lock);

	return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
}

Project: linux
File: trace.c

ftrace_snapshot_init(struct ftrace_probe_ops *ops, struct trace_array *tr,
		     unsigned long ip, void *init_data, void **data)
{
	struct ftrace_func_mapper *mapper = *data;

	if (!mapper) {
		mapper = allocate_ftrace_func_mapper();
		if (!mapper)
			return -ENOMEM;
		*data = mapper;
	}

	return ftrace_func_mapper_add_ip(mapper, ip, init_data);
}

Project: linux
File: trace.c

int tracer_tracing_is_on(struct trace_array *tr)
{
	if (tr->trace_buffer.buffer)
		return ring_buffer_record_is_on(tr->trace_buffer.buffer);
	return !tr->buffer_disabled;
}

Project: linux
File: trace.c

static void buffer_spd_release(struct splice_pipe_desc *spd, unsigned int i)
{
	struct buffer_ref *ref =
		(struct buffer_ref *)spd->partial[i].private;

	if (--ref->ref)
		return;

	ring_buffer_free_read_page(ref->buffer, ref->cpu, ref->page);
	kfree(ref);
	spd->partial[i].private = 0;
}

Project: linux
File: trace.c

static void trace_iterator_increment(struct trace_iterator *iter)
{
	struct ring_buffer_iter *buf_iter = trace_buffer_iter(iter, iter->cpu);

	iter->idx++;
	if (buf_iter)
		ring_buffer_read(buf_iter, NULL);
}

Project: linux
File: trace.c

static void print_lat_help_header(struct seq_file *m)
{
	seq_puts(m, "#                  _------=> CPU#            \n"
		    "#                 / _-----=> irqs-off        \n"
		    "#                | / _----=> need-resched    \n"
		    "#                || / _---=> hardirq/softirq \n"
		    "#                ||| / _--=> preempt-depth   \n"
		    "#                |||| /     delay            \n"
		    "#  cmd     pid   ||||| time  |   caller      \n"
		    "#     \\   /      |||||  \\    |   /         \n");
}

Project: linux
File: trace.c

static int __init set_ftrace_dump_on_oops(char *str)
{
	if (*str++ != '=' || !*str) {
		ftrace_dump_on_oops = DUMP_ALL;
		return 1;
	}

	if (!strcmp("orig_cpu", str)) {
		ftrace_dump_on_oops = DUMP_ORIG;
                return 1;
        }

        return 0;
}

Project: linux
File: trace.c

t_next(struct seq_file *m, void *v, loff_t *pos)
{
	struct trace_array *tr = m->private;
	struct tracer *t = v;

	(*pos)++;

	if (t)
		t = get_tracer_for_array(tr, t->next);

	return t;
}

Project: linux
File: trace.c

static ssize_t tracing_resize_ring_buffer(struct trace_array *tr,
					  unsigned long size, int cpu_id)
{
	int ret = size;

	mutex_lock(&trace_types_lock);

	if (cpu_id != RING_BUFFER_ALL_CPUS) {
		/* make sure, this cpu is enabled in the mask */
		if (!cpumask_test_cpu(cpu_id, tracing_buffer_mask)) {
			ret = -EINVAL;
			goto out;
		}
	}

	ret = __tracing_resize_ring_buffer(tr, size, cpu_id);
	if (ret < 0)
		ret = -ENOMEM;

out:
	mutex_unlock(&trace_types_lock);

	return ret;
}

Project: linux
File: trace.c

add_ftrace_export(struct trace_export **list, struct trace_export *export)
{
	if (*list == NULL)
		ftrace_exports_enable();

	add_trace_export(list, export);
}

Project: linux
File: trace.c

static inline int tracing_get_cpu(struct inode *inode)
{
	if (inode->i_cdev) /* See trace_create_cpu_file() */
		return (long)inode->i_cdev - 1;
	return RING_BUFFER_ALL_CPUS;
}

Project: linux
File: trace.c

void trace_printk_start_comm(void)
{
	/* Start tracing comms if trace printk is set */
	if (!buffers_allocated)
		return;
	tracing_start_cmdline_record();
}

Project: linux
File: trace.c

static void t_stop(struct seq_file *m, void *p)
{
	mutex_unlock(&trace_types_lock);
}

Project: linux
File: trace.c

static int alloc_snapshot(struct trace_array *tr)
{
	int ret;

	if (!tr->allocated_snapshot) {

		/* allocate spare buffer */
		ret = resize_buffer_duplicate_size(&tr->max_buffer,
				   &tr->trace_buffer, RING_BUFFER_ALL_CPUS);
		if (ret < 0)
			return ret;

		tr->allocated_snapshot = true;
	}

	return 0;
}

Project: linux
File: trace.c

int tracing_is_on(void)
{
	return tracer_tracing_is_on(&global_trace);
}

Project: linux
File: trace.c

static char *get_trace_buf(void)
{
	struct trace_buffer_struct *buffer = this_cpu_ptr(trace_percpu_buffer);

	if (!buffer || buffer->nesting >= 4)
		return NULL;

	buffer->nesting++;

	/* Interrupts must see nesting incremented before we use the buffer */
	barrier();
	return &buffer->buffer[buffer->nesting][0];
}

Project: linux
File: trace.c

static void free_trace_buffer(struct trace_buffer *buf)
{
	if (buf->buffer) {
		ring_buffer_free(buf->buffer);
		buf->buffer = NULL;
		free_percpu(buf->data);
		buf->data = NULL;
	}
}

Project: linux
File: trace.c

int register_ftrace_export(struct trace_export *export)
{
	if (WARN_ON_ONCE(!export->write))
		return -1;

	mutex_lock(&ftrace_export_lock);

	add_ftrace_export(&ftrace_exports_list, export);

	mutex_unlock(&ftrace_export_lock);

	return 0;
}

Project: linux
File: trace.c

static int __init set_trace_boot_options(char *str)
{
	strlcpy(trace_boot_options_buf, str, MAX_TRACER_SIZE);
	return 0;
}

Project: linux
File: trace.c

tracing_nsecs_read(unsigned long *ptr, char __user *ubuf,
		   size_t cnt, loff_t *ppos)
{
	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);
}

Project: linux
File: trace.c

int call_filter_check_discard(struct trace_event_call *call, void *rec,
			      struct ring_buffer *buffer,
			      struct ring_buffer_event *event)
{
	if (unlikely(call->flags & TRACE_EVENT_FL_FILTERED) &&
	    !filter_match_preds(call->filter, rec)) {
		__trace_event_discard_commit(buffer, event);
		return 1;
	}

	return 0;
}

Project: linux
File: trace.c

static void __trace_array_put(struct trace_array *this_tr)
{
	WARN_ON(!this_tr->ref);
	this_tr->ref--;
}

Project: linux
File: trace.c

trace_function(struct trace_array *tr,
	       unsigned long ip, unsigned long parent_ip, unsigned long flags,
	       int pc)
{
	struct trace_event_call *call = &event_function;
	struct ring_buffer *buffer = tr->trace_buffer.buffer;
	struct ring_buffer_event *event;
	struct ftrace_entry *entry;

	event = __trace_buffer_lock_reserve(buffer, TRACE_FN, sizeof(*entry),
					    flags, pc);
	if (!event)
		return;
	entry	= ring_buffer_event_data(event);
	entry->ip			= ip;
	entry->parent_ip		= parent_ip;

	if (!call_filter_check_discard(call, entry, buffer, event)) {
		if (static_branch_unlikely(&ftrace_exports_enabled))
			ftrace_exports(event);
		__buffer_unlock_commit(buffer, event);
	}
}

Project: linux
File: trace.c

ssize_t trace_parse_run_command(struct file *file, const char __user *buffer,
				size_t count, loff_t *ppos,
				int (*createfn)(int, char **))
{
	char *kbuf, *buf, *tmp;
	int ret = 0;
	size_t done = 0;
	size_t size;

	kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL);
	if (!kbuf)
		return -ENOMEM;

	while (done < count) {
		size = count - done;

		if (size >= WRITE_BUFSIZE)
			size = WRITE_BUFSIZE - 1;

		if (copy_from_user(kbuf, buffer + done, size)) {
			ret = -EFAULT;
			goto out;
		}
		kbuf[size] = '\0';
		buf = kbuf;
		do {
			tmp = strchr(buf, '\n');
			if (tmp) {
				*tmp = '\0';
				size = tmp - buf + 1;
			} else {
				size = strlen(buf);
				if (done + size < count) {
					if (buf != kbuf)
						break;
					/* This can accept WRITE_BUFSIZE - 2 ('\n' + '\0') */
					pr_warn("Line length is too long: Should be less than %d\n",
						WRITE_BUFSIZE - 2);
					ret = -EINVAL;
					goto out;
				}
			}
			done += size;

			/* Remove comments */
			tmp = strchr(buf, '#');

			if (tmp)
				*tmp = '\0';

			ret = trace_run_command(buf, createfn);
			if (ret)
				goto out;
			buf += size;

		} while (done < count);
	}
	ret = done;

out:
	kfree(kbuf);

	return ret;
}

Project: linux
File: trace.c

int trace_parser_get_init(struct trace_parser *parser, int size)
{
	memset(parser, 0, sizeof(*parser));

	parser->buffer = kmalloc(size, GFP_KERNEL);
	if (!parser->buffer)
		return 1;

	parser->size = size;
	return 0;
}

Project: linux
File: trace.c

init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer)
{
	int cpu;

	trace_create_file("available_tracers", 0444, d_tracer,
			tr, &show_traces_fops);

	trace_create_file("current_tracer", 0644, d_tracer,
			tr, &set_tracer_fops);

	trace_create_file("tracing_cpumask", 0644, d_tracer,
			  tr, &tracing_cpumask_fops);

	trace_create_file("trace_options", 0644, d_tracer,
			  tr, &tracing_iter_fops);

	trace_create_file("trace", 0644, d_tracer,
			  tr, &tracing_fops);

	trace_create_file("trace_pipe", 0444, d_tracer,
			  tr, &tracing_pipe_fops);

	trace_create_file("buffer_size_kb", 0644, d_tracer,
			  tr, &tracing_entries_fops);

	trace_create_file("buffer_total_size_kb", 0444, d_tracer,
			  tr, &tracing_total_entries_fops);

	trace_create_file("free_buffer", 0200, d_tracer,
			  tr, &tracing_free_buffer_fops);

	trace_create_file("trace_marker", 0220, d_tracer,
			  tr, &tracing_mark_fops);

	trace_create_file("trace_marker_raw", 0220, d_tracer,
			  tr, &tracing_mark_raw_fops);

	trace_create_file("trace_clock", 0644, d_tracer, tr,
			  &trace_clock_fops);

	trace_create_file("tracing_on", 0644, d_tracer,
			  tr, &rb_simple_fops);

	create_trace_options_dir(tr);

#if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
	trace_create_file("tracing_max_latency", 0644, d_tracer,
			&tr->max_latency, &tracing_max_lat_fops);
#endif

	if (ftrace_create_function_files(tr, d_tracer))
		WARN(1, "Could not allocate function filter files");

#ifdef CONFIG_TRACER_SNAPSHOT
	trace_create_file("snapshot", 0644, d_tracer,
			  tr, &snapshot_fops);
#endif

	for_each_tracing_cpu(cpu)
		tracing_init_tracefs_percpu(tr, cpu);

	ftrace_init_tracefs(tr, d_tracer);
}

Project: linux
File: trace.c

static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt)
{
	int len;

	if (trace_seq_used(s) <= s->seq.readpos)
		return -EBUSY;

	len = trace_seq_used(s) - s->seq.readpos;
	if (cnt > len)
		cnt = len;
	memcpy(buf, s->buffer + s->seq.readpos, cnt);

	s->seq.readpos += cnt;
	return cnt;
}

Project: linux
File: trace.c

unsigned long nsecs_to_usecs(unsigned long nsecs)
{
	return nsecs / 1000;
}

Project: linux
File: trace.c

void tracing_record_cmdline(struct task_struct *task)
{
	tracing_record_taskinfo(task, TRACE_RECORD_CMDLINE);
}

Project: linux
File: trace.c

static int tracing_buffers_open(struct inode *inode, struct file *filp)
{
	struct trace_array *tr = inode->i_private;
	struct ftrace_buffer_info *info;
	int ret;

	if (tracing_disabled)
		return -ENODEV;

	if (trace_array_get(tr) < 0)
		return -ENODEV;

	info = kzalloc(sizeof(*info), GFP_KERNEL);
	if (!info) {
		trace_array_put(tr);
		return -ENOMEM;
	}

	mutex_lock(&trace_types_lock);

	info->iter.tr		= tr;
	info->iter.cpu_file	= tracing_get_cpu(inode);
	info->iter.trace	= tr->current_trace;
	info->iter.trace_buffer = &tr->trace_buffer;
	info->spare		= NULL;
	/* Force reading ring buffer for first read */
	info->read		= (unsigned int)-1;

	filp->private_data = info;

	tr->current_trace->ref++;

	mutex_unlock(&trace_types_lock);

	ret = nonseekable_open(inode, filp);
	if (ret < 0)
		trace_array_put(tr);

	return ret;
}

Project: linux
File: trace.c

int tracer_init(struct tracer *t, struct trace_array *tr)
{
	tracing_reset_online_cpus(&tr->trace_buffer);
	return t->init(tr);
}

Project: linux
File: trace.c

static inline void ftrace_exports_enable(void)
{
	static_branch_enable(&ftrace_exports_enabled);
}

Project: linux
File: trace.c

static inline void __ftrace_trace_stack(struct ring_buffer *buffer,
					unsigned long flags,
					int skip, int pc, struct pt_regs *regs)
{
}

Project: linux
File: trace.c

static int trace_panic_handler(struct notifier_block *this,
			       unsigned long event, void *unused)
{
	if (ftrace_dump_on_oops)
		ftrace_dump(ftrace_dump_on_oops);
	return NOTIFY_OK;
}

Project: linux
File: trace.c

void tracing_on(void)
{
	tracer_tracing_on(&global_trace);
}

Project: linux
File: trace.c

tracing_read_dyn_info(struct file *filp, char __user *ubuf,
		  size_t cnt, loff_t *ppos)
{
	unsigned long *p = filp->private_data;
	char buf[64]; /* Not too big for a shallow stack */
	int r;

	r = scnprintf(buf, 63, "%ld", *p);
	buf[r++] = '\n';

	return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
}

Project: linux
File: trace.c

int tracepoint_printk_sysctl(struct ctl_table *table, int write,
			     void __user *buffer, size_t *lenp,
			     loff_t *ppos)
{
	int save_tracepoint_printk;
	int ret;

	mutex_lock(&tracepoint_printk_mutex);
	save_tracepoint_printk = tracepoint_printk;

	ret = proc_dointvec(table, write, buffer, lenp, ppos);

	/*
	 * This will force exiting early, as tracepoint_printk
	 * is always zero when tracepoint_printk_iter is not allocated
	 */
	if (!tracepoint_print_iter)
		tracepoint_printk = 0;

	if (save_tracepoint_printk == tracepoint_printk)
		goto out;

	if (tracepoint_printk)
		static_key_enable(&tracepoint_printk_key.key);
	else
		static_key_disable(&tracepoint_printk_key.key);

 out:
	mutex_unlock(&tracepoint_printk_mutex);

	return ret;
}

Project: linux
File: trace.c

update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
{
	int ret;

	if (tr->stop_count)
		return;

	WARN_ON_ONCE(!irqs_disabled());
	if (!tr->allocated_snapshot) {
		/* Only the nop tracer should hit this when disabling */
		WARN_ON_ONCE(tr->current_trace != &nop_trace);
		return;
	}

	arch_spin_lock(&tr->max_lock);

	ret = ring_buffer_swap_cpu(tr->max_buffer.buffer, tr->trace_buffer.buffer, cpu);

	if (ret == -EBUSY) {
		/*
		 * We failed to swap the buffer due to a commit taking
		 * place on this CPU. We fail to record, but we reset
		 * the max trace buffer (no one writes directly to it)
		 * and flag that it failed.
		 */
		trace_array_printk_buf(tr->max_buffer.buffer, _THIS_IP_,
			"Failed to swap buffers due to commit in progress\n");
	}

	WARN_ON_ONCE(ret && ret != -EAGAIN && ret != -EBUSY);

	__update_max_tr(tr, tsk, cpu);
	arch_spin_unlock(&tr->max_lock);
}

Project: linux
File: trace.c

static int tracing_release_pipe(struct inode *inode, struct file *file)
{
	struct trace_iterator *iter = file->private_data;
	struct trace_array *tr = inode->i_private;

	mutex_lock(&trace_types_lock);

	tr->current_trace->ref--;

	if (iter->trace->pipe_close)
		iter->trace->pipe_close(iter);

	mutex_unlock(&trace_types_lock);

	free_cpumask_var(iter->started);
	mutex_destroy(&iter->mutex);
	kfree(iter);

	trace_array_put(tr);

	return 0;
}

Project: linux
File: trace.c

static inline void trace_access_unlock(int cpu)
{
	(void)cpu;
	mutex_unlock(&access_lock);
}

Project: linux
File: trace.c

static inline void trace_module_remove_evals(struct module *mod) { }

Project: linux
File: trace.c

void __init trace_init(void)
{
	trace_event_init();
}

Project: linux
File: trace.c

static void saved_cmdlines_stop(struct seq_file *m, void *v)
{
	arch_spin_unlock(&trace_cmdline_lock);
	preempt_enable();
}

Project: linux
File: trace.c

static inline void ftrace_trace_stack(struct trace_array *tr,
				      struct ring_buffer *buffer,
				      unsigned long flags,
				      int skip, int pc, struct pt_regs *regs)
{
	if (!(tr->trace_flags & TRACE_ITER_STACKTRACE))
		return;

	__ftrace_trace_stack(buffer, flags, skip, pc, regs);
}

Project: linux
File: trace.c

static void free_snapshot(struct trace_array *tr)
{
	/*
	 * We don't free the ring buffer. instead, resize it because
	 * The max_tr ring buffer has some state (e.g. ring->clock) and
	 * we want preserve it.
	 */
	ring_buffer_resize(tr->max_buffer.buffer, 1, RING_BUFFER_ALL_CPUS);
	set_buffer_entries(&tr->max_buffer, 1);
	tracing_reset_online_cpus(&tr->max_buffer);
	tr->allocated_snapshot = false;
}

Project: linux
File: trace.c

void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos)
{
	unsigned long pid;
	loff_t l = 0;

	pid = find_first_bit(pid_list->pids, pid_list->pid_max);
	if (pid >= pid_list->pid_max)
		return NULL;

	/* Return pid + 1 so that zero can be the exit value */
	for (pid++; pid && l < *pos;
	     pid = (unsigned long)trace_pid_next(pid_list, (void *)pid, &l))
		;
	return (void *)pid;
}

Project: linux
File: trace.c

static void disable_trace_buffered_event(void *data)
{
	this_cpu_inc(trace_buffered_event_cnt);
}

Project: linux
File: trace.c

static void *s_start(struct seq_file *m, loff_t *pos)
{
	struct trace_iterator *iter = m->private;
	struct trace_array *tr = iter->tr;
	int cpu_file = iter->cpu_file;
	void *p = NULL;
	loff_t l = 0;
	int cpu;

	/*
	 * copy the tracer to avoid using a global lock all around.
	 * iter->trace is a copy of current_trace, the pointer to the
	 * name may be used instead of a strcmp(), as iter->trace->name
	 * will point to the same string as current_trace->name.
	 */
	mutex_lock(&trace_types_lock);
	if (unlikely(tr->current_trace && iter->trace->name != tr->current_trace->name))
		*iter->trace = *tr->current_trace;
	mutex_unlock(&trace_types_lock);

#ifdef CONFIG_TRACER_MAX_TRACE
	if (iter->snapshot && iter->trace->use_max_tr)
		return ERR_PTR(-EBUSY);
#endif

	if (!iter->snapshot)
		atomic_inc(&trace_record_taskinfo_disabled);

	if (*pos != iter->pos) {
		iter->ent = NULL;
		iter->cpu = 0;
		iter->idx = -1;

		if (cpu_file == RING_BUFFER_ALL_CPUS) {
			for_each_tracing_cpu(cpu)
				tracing_iter_reset(iter, cpu);
		} else
			tracing_iter_reset(iter, cpu_file);

		iter->leftover = 0;
		for (p = iter; p && l < *pos; p = s_next(m, p, &l))
			;

	} else {
		/*
		 * If we overflowed the seq_file before, then we want
		 * to just reuse the trace_seq buffer again.
		 */
		if (iter->leftover)
			p = iter;
		else {
			l = *pos - 1;
			p = s_next(m, p, &l);
		}
	}

	trace_event_read_lock();
	trace_access_lock(cpu_file);
	return p;
}

Project: linux
File: trace.c

static int tracing_single_release_tr(struct inode *inode, struct file *file)
{
	struct trace_array *tr = inode->i_private;

	trace_array_put(tr);

	return single_release(inode, file);
}

Project: linux
File: trace.c

static int tracing_snapshot_release(struct inode *inode, struct file *file)
{
	struct seq_file *m = file->private_data;
	int ret;

	ret = tracing_release(inode, file);

	if (file->f_mode & FMODE_READ)
		return ret;

	/* If write only, the seq_file is just a stub */
	if (m)
		kfree(m->private);
	kfree(m);

	return 0;
}

Project: linux
File: trace.c

static void print_snapshot_help(struct seq_file *m, struct trace_iterator *iter)
{
	if (iter->tr->allocated_snapshot)
		seq_puts(m, "#\n# * Snapshot is allocated *\n#\n");
	else
		seq_puts(m, "#\n# * Snapshot is freed *\n#\n");

	seq_puts(m, "# Snapshot commands:\n");
	if (iter->cpu_file == RING_BUFFER_ALL_CPUS)
		show_snapshot_main_help(m);
	else
		show_snapshot_percpu_help(m);
}

Project: linux
File: trace.c

bool tracing_is_disabled(void)
{
	return (tracing_disabled) ? true: false;
}

Project: linux
File: trace.c

tracing_mark_raw_write(struct file *filp, const char __user *ubuf,
					size_t cnt, loff_t *fpos)
{
	struct trace_array *tr = filp->private_data;
	struct ring_buffer_event *event;
	struct ring_buffer *buffer;
	struct raw_data_entry *entry;
	const char faulted[] = "<faulted>";
	unsigned long irq_flags;
	ssize_t written;
	int size;
	int len;

#define FAULT_SIZE_ID (FAULTED_SIZE + sizeof(int))

	if (tracing_disabled)
		return -EINVAL;

	if (!(tr->trace_flags & TRACE_ITER_MARKERS))
		return -EINVAL;

	/* The marker must at least have a tag id */
	if (cnt < sizeof(unsigned int) || cnt > RAW_DATA_MAX_SIZE)
		return -EINVAL;

	if (cnt > TRACE_BUF_SIZE)
		cnt = TRACE_BUF_SIZE;

	BUILD_BUG_ON(TRACE_BUF_SIZE >= PAGE_SIZE);

	local_save_flags(irq_flags);
	size = sizeof(*entry) + cnt;
	if (cnt < FAULT_SIZE_ID)
		size += FAULT_SIZE_ID - cnt;

	buffer = tr->trace_buffer.buffer;
	event = __trace_buffer_lock_reserve(buffer, TRACE_RAW_DATA, size,
					    irq_flags, preempt_count());
	if (!event)
		/* Ring buffer disabled, return as if not open for write */
		return -EBADF;

	entry = ring_buffer_event_data(event);

	len = __copy_from_user_inatomic(&entry->id, ubuf, cnt);
	if (len) {
		entry->id = -1;
		memcpy(&entry->buf, faulted, FAULTED_SIZE);
		written = -EFAULT;
	} else
		written = cnt;

	__buffer_unlock_commit(buffer, event);

	if (written > 0)
		*fpos += written;

	return written;
}

Project: linux
File: trace.c

static int trace_module_notify(struct notifier_block *self,
			       unsigned long val, void *data)
{
	struct module *mod = data;

	switch (val) {
	case MODULE_STATE_COMING:
		trace_module_add_evals(mod);
		break;
	case MODULE_STATE_GOING:
		trace_module_remove_evals(mod);
		break;
	}

	return 0;
}

Project: linux
File: trace.c

trace_event_buffer_lock_reserve(struct ring_buffer **current_rb,
			  struct trace_event_file *trace_file,
			  int type, unsigned long len,
			  unsigned long flags, int pc)
{
	struct ring_buffer_event *entry;
	int val;

	*current_rb = trace_file->tr->trace_buffer.buffer;

	if ((trace_file->flags &
	     (EVENT_FILE_FL_SOFT_DISABLED | EVENT_FILE_FL_FILTERED)) &&
	    (entry = this_cpu_read(trace_buffered_event))) {
		/* Try to use the per cpu buffer first */
		val = this_cpu_inc_return(trace_buffered_event_cnt);
		if (val == 1) {
			trace_event_setup(entry, type, flags, pc);
			entry->array[0] = len;
			return entry;
		}
		this_cpu_dec(trace_buffered_event_cnt);
	}

	entry = __trace_buffer_lock_reserve(*current_rb,
					    type, len, flags, pc);
	/*
	 * If tracing is off, but we have triggers enabled
	 * we still need to look at the event data. Use the temp_buffer
	 * to store the trace event for the tigger to use. It's recusive
	 * safe and will not be recorded anywhere.
	 */
	if (!entry && trace_file->flags & EVENT_FILE_FL_TRIGGER_COND) {
		*current_rb = temp_buffer;
		entry = __trace_buffer_lock_reserve(*current_rb,
						    type, len, flags, pc);
	}
	return entry;
}

Project: linux
File: trace.c

trace_process_export(struct trace_export *export,
	       struct ring_buffer_event *event)
{
	struct trace_entry *entry;
	unsigned int size = 0;

	entry = ring_buffer_event_data(event);
	size = ring_buffer_event_length(event);
	export->write(export, entry, size);
}

Project: linux
File: trace.c

__trace_buffer_lock_reserve(struct ring_buffer *buffer,
			  int type,
			  unsigned long len,
			  unsigned long flags, int pc)
{
	struct ring_buffer_event *event;

	event = ring_buffer_lock_reserve(buffer, len);
	if (event != NULL)
		trace_event_setup(event, type, flags, pc);

	return event;
}

Project: linux
File: trace.c

tracing_stats_read(struct file *filp, char __user *ubuf,
		   size_t count, loff_t *ppos)
{
	struct inode *inode = file_inode(filp);
	struct trace_array *tr = inode->i_private;
	struct trace_buffer *trace_buf = &tr->trace_buffer;
	int cpu = tracing_get_cpu(inode);
	struct trace_seq *s;
	unsigned long cnt;
	unsigned long long t;
	unsigned long usec_rem;

	s = kmalloc(sizeof(*s), GFP_KERNEL);
	if (!s)
		return -ENOMEM;

	trace_seq_init(s);

	cnt = ring_buffer_entries_cpu(trace_buf->buffer, cpu);
	trace_seq_printf(s, "entries: %ld\n", cnt);

	cnt = ring_buffer_overrun_cpu(trace_buf->buffer, cpu);
	trace_seq_printf(s, "overrun: %ld\n", cnt);

	cnt = ring_buffer_commit_overrun_cpu(trace_buf->buffer, cpu);
	trace_seq_printf(s, "commit overrun: %ld\n", cnt);

	cnt = ring_buffer_bytes_cpu(trace_buf->buffer, cpu);
	trace_seq_printf(s, "bytes: %ld\n", cnt);

	if (trace_clocks[tr->clock_id].in_ns) {
		/* local or global for trace_clock */
		t = ns2usecs(ring_buffer_oldest_event_ts(trace_buf->buffer, cpu));
		usec_rem = do_div(t, USEC_PER_SEC);
		trace_seq_printf(s, "oldest event ts: %5llu.%06lu\n",
								t, usec_rem);

		t = ns2usecs(ring_buffer_time_stamp(trace_buf->buffer, cpu));
		usec_rem = do_div(t, USEC_PER_SEC);
		trace_seq_printf(s, "now ts: %5llu.%06lu\n", t, usec_rem);
	} else {
		/* counter or tsc mode for trace_clock */
		trace_seq_printf(s, "oldest event ts: %llu\n",
				ring_buffer_oldest_event_ts(trace_buf->buffer, cpu));

		trace_seq_printf(s, "now ts: %llu\n",
				ring_buffer_time_stamp(trace_buf->buffer, cpu));
	}

	cnt = ring_buffer_dropped_events_cpu(trace_buf->buffer, cpu);
	trace_seq_printf(s, "dropped events: %ld\n", cnt);

	cnt = ring_buffer_read_events_cpu(trace_buf->buffer, cpu);
	trace_seq_printf(s, "read events: %ld\n", cnt);

	count = simple_read_from_buffer(ubuf, count, ppos,
					s->buffer, trace_seq_used(s));

	kfree(s);

	return count;
}

Project: linux
File: trace.c

__trace_array_vprintk(struct ring_buffer *buffer,
		      unsigned long ip, const char *fmt, va_list args)
{
	struct trace_event_call *call = &event_print;
	struct ring_buffer_event *event;
	int len = 0, size, pc;
	struct print_entry *entry;
	unsigned long flags;
	char *tbuffer;

	if (tracing_disabled || tracing_selftest_running)
		return 0;

	/* Don't pollute graph traces with trace_vprintk internals */
	pause_graph_tracing();

	pc = preempt_count();
	preempt_disable_notrace();


	tbuffer = get_trace_buf();
	if (!tbuffer) {
		len = 0;
		goto out_nobuffer;
	}

	len = vscnprintf(tbuffer, TRACE_BUF_SIZE, fmt, args);

	local_save_flags(flags);
	size = sizeof(*entry) + len + 1;
	event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, size,
					    flags, pc);
	if (!event)
		goto out;
	entry = ring_buffer_event_data(event);
	entry->ip = ip;

	memcpy(&entry->buf, tbuffer, len + 1);
	if (!call_filter_check_discard(call, entry, buffer, event)) {
		__buffer_unlock_commit(buffer, event);
		ftrace_trace_stack(&global_trace, buffer, flags, 6, pc, NULL);
	}

out:
	put_trace_buf();

out_nobuffer:
	preempt_enable_notrace();
	unpause_graph_tracing();

	return len;
}

Project: linux
File: trace.c

static inline void ftrace_exports_disable(void)
{
	static_branch_disable(&ftrace_exports_enabled);
}

Project: linux
File: trace.c

static int __init set_buf_size(char *str)
{
	unsigned long buf_size;

	if (!str)
		return 0;
	buf_size = memparse(str, &str);
	/* nr_entries can not be zero */
	if (buf_size == 0)
		return 0;
	trace_buf_size = buf_size;
	return 1;
}

Project: linux
File: trace.c

struct dentry *tracing_init_dentry(void)
{
	struct trace_array *tr = &global_trace;

	/* The top level trace array uses  NULL as parent */
	if (tr->dir)
		return NULL;

	if (WARN_ON(!tracefs_initialized()) ||
		(IS_ENABLED(CONFIG_DEBUG_FS) &&
		 WARN_ON(!debugfs_initialized())))
		return ERR_PTR(-ENODEV);

	/*
	 * As there may still be users that expect the tracing
	 * files to exist in debugfs/tracing, we must automount
	 * the tracefs file system there, so older tools still
	 * work with the newer kerenl.
	 */
	tr->dir = debugfs_create_automount("tracing", NULL,
					   trace_automount, NULL);
	if (!tr->dir) {
		pr_warn_once("Could not create debugfs directory 'tracing'\n");
		return ERR_PTR(-ENOMEM);
	}

	return NULL;
}

Project: linux
File: trace.c

peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts,
		unsigned long *lost_events)
{
	struct ring_buffer_event *event;
	struct ring_buffer_iter *buf_iter = trace_buffer_iter(iter, cpu);

	if (buf_iter)
		event = ring_buffer_iter_peek(buf_iter, ts);
	else
		event = ring_buffer_peek(iter->trace_buffer->buffer, cpu, ts,
					 lost_events);

	if (event) {
		iter->ent_size = ring_buffer_event_length(event);
		return ring_buffer_event_data(event);
	}
	iter->ent_size = 0;
	return NULL;
}

Project: linux
File: trace.c

void trace_find_cmdline(int pid, char comm[])
{
	preempt_disable();
	arch_spin_lock(&trace_cmdline_lock);

	__trace_find_cmdline(pid, comm);

	arch_spin_unlock(&trace_cmdline_lock);
	preempt_enable();
}

Project: linux
File: trace.c

static int instance_mkdir(const char *name)
{
	struct trace_array *tr;
	int ret;

	mutex_lock(&event_mutex);
	mutex_lock(&trace_types_lock);

	ret = -EEXIST;
	list_for_each_entry(tr, &ftrace_trace_arrays, list) {
		if (tr->name && strcmp(tr->name, name) == 0)
			goto out_unlock;
	}

	ret = -ENOMEM;
	tr = kzalloc(sizeof(*tr), GFP_KERNEL);
	if (!tr)
		goto out_unlock;

	tr->name = kstrdup(name, GFP_KERNEL);
	if (!tr->name)
		goto out_free_tr;

	if (!alloc_cpumask_var(&tr->tracing_cpumask, GFP_KERNEL))
		goto out_free_tr;

	tr->trace_flags = global_trace.trace_flags & ~ZEROED_TRACE_FLAGS;

	cpumask_copy(tr->tracing_cpumask, cpu_all_mask);

	raw_spin_lock_init(&tr->start_lock);

	tr->max_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;

	tr->current_trace = &nop_trace;

	INIT_LIST_HEAD(&tr->systems);
	INIT_LIST_HEAD(&tr->events);

	if (allocate_trace_buffers(tr, trace_buf_size) < 0)
		goto out_free_tr;

	tr->dir = tracefs_create_dir(name, trace_instance_dir);
	if (!tr->dir)
		goto out_free_tr;

	ret = event_trace_add_tracer(tr->dir, tr);
	if (ret) {
		tracefs_remove_recursive(tr->dir);
		goto out_free_tr;
	}

	ftrace_init_trace_array(tr);

	init_tracer_tracefs(tr, tr->dir);
	init_trace_flags_index(tr);
	__update_tracer_options(tr);

	list_add(&tr->list, &ftrace_trace_arrays);

	mutex_unlock(&trace_types_lock);
	mutex_unlock(&event_mutex);

	return 0;

 out_free_tr:
	free_trace_buffers(tr);
	free_cpumask_var(tr->tracing_cpumask);
	kfree(tr->name);
	kfree(tr);

 out_unlock:
	mutex_unlock(&trace_types_lock);
	mutex_unlock(&event_mutex);

	return ret;

}

Project: linux
File: trace.c

create_trace_option_files(struct trace_array *tr, struct tracer *tracer)
{
	struct trace_option_dentry *topts;
	struct trace_options *tr_topts;
	struct tracer_flags *flags;
	struct tracer_opt *opts;
	int cnt;
	int i;

	if (!tracer)
		return;

	flags = tracer->flags;

	if (!flags || !flags->opts)
		return;

	/*
	 * If this is an instance, only create flags for tracers
	 * the instance may have.
	 */
	if (!trace_ok_for_array(tracer, tr))
		return;

	for (i = 0; i < tr->nr_topts; i++) {
		/* Make sure there's no duplicate flags. */
		if (WARN_ON_ONCE(tr->topts[i].tracer->flags == tracer->flags))
			return;
	}

	opts = flags->opts;

	for (cnt = 0; opts[cnt].name; cnt++)
		;

	topts = kcalloc(cnt + 1, sizeof(*topts), GFP_KERNEL);
	if (!topts)
		return;

	tr_topts = krealloc(tr->topts, sizeof(*tr->topts) * (tr->nr_topts + 1),
			    GFP_KERNEL);
	if (!tr_topts) {
		kfree(topts);
		return;
	}

	tr->topts = tr_topts;
	tr->topts[tr->nr_topts].tracer = tracer;
	tr->topts[tr->nr_topts].topts = topts;
	tr->nr_topts++;

	for (cnt = 0; opts[cnt].name; cnt++) {
		create_trace_option_file(tr, &topts[cnt], flags,
					 &opts[cnt]);
		WARN_ONCE(topts[cnt].entry == NULL,
			  "Failed to create trace option: %s",
			  opts[cnt].name);
	}
}

Project: linux
File: trace.c

void tracing_reset_online_cpus(struct trace_buffer *buf)
{
	struct ring_buffer *buffer = buf->buffer;
	int cpu;

	if (!buffer)
		return;

	ring_buffer_record_disable(buffer);

	/* Make sure all commits have finished */
	synchronize_sched();

	buf->time_start = buffer_ftrace_now(buf, buf->cpu);

	for_each_online_cpu(cpu)
		ring_buffer_reset_cpu(buffer, cpu);

	ring_buffer_record_enable(buffer);
}

Project: linux
File: trace.c

static int snapshot_raw_open(struct inode *inode, struct file *filp)
{
	struct ftrace_buffer_info *info;
	int ret;

	ret = tracing_buffers_open(inode, filp);
	if (ret < 0)
		return ret;

	info = filp->private_data;

	if (info->iter.trace->use_max_tr) {
		tracing_buffers_release(inode, filp);
		return -EBUSY;
	}

	info->iter.snapshot = true;
	info->iter.trace_buffer = &info->iter.tr->max_buffer;

	return ret;
}

Project: linux
File: trace.c

tracing_set_trace_write(struct file *filp, const char __user *ubuf,
			size_t cnt, loff_t *ppos)
{
	struct trace_array *tr = filp->private_data;
	char buf[MAX_TRACER_SIZE+1];
	int i;
	size_t ret;
	int err;

	ret = cnt;

	if (cnt > MAX_TRACER_SIZE)
		cnt = MAX_TRACER_SIZE;

	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(tr, buf);
	if (err)
		return err;

	*ppos += ret;

	return ret;
}

Project: linux
File: trace.c

static inline void print_snapshot_help(struct seq_file *m, struct trace_iterator *iter) { }

Project: linux
File: trace.c

static void trace_insert_eval_map(struct module *mod,
				  struct trace_eval_map **start, int len)
{
	struct trace_eval_map **map;

	if (len <= 0)
		return;

	map = start;

	trace_event_eval_update(map, len);

	trace_insert_eval_map_file(mod, start, len);
}

Project: linux
File: trace.c

void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
				  struct task_struct *self,
				  struct task_struct *task)
{
	if (!pid_list)
		return;

	/* For forks, we only add if the forking task is listed */
	if (self) {
		if (!trace_find_filtered_pid(pid_list, self->pid))
			return;
	}

	/* Sorry, but we don't support pid_max changing after setting */
	if (task->pid >= pid_list->pid_max)
		return;

	/* "self" is set for forks, and NULL for exits */
	if (self)
		set_bit(task->pid, pid_list->pids);
	else
		clear_bit(task->pid, pid_list->pids);
}

Project: linux
File: trace.c

static int t_show(struct seq_file *m, void *v)
{
	struct tracer *t = v;

	if (!t)
		return 0;

	seq_puts(m, t->name);
	if (t->next)
		seq_putc(m, ' ');
	else
		seq_putc(m, '\n');

	return 0;
}

Project: linux
File: trace.c

void trace_parser_put(struct trace_parser *parser)
{
	kfree(parser->buffer);
	parser->buffer = NULL;
}

Project: linux
File: trace.c

static enum print_line_t print_hex_fmt(struct trace_iterator *iter)
{
	struct trace_array *tr = iter->tr;
	struct trace_seq *s = &iter->seq;
	unsigned char newline = '\n';
	struct trace_entry *entry;
	struct trace_event *event;

	entry = iter->ent;

	if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) {
		SEQ_PUT_HEX_FIELD(s, entry->pid);
		SEQ_PUT_HEX_FIELD(s, iter->cpu);
		SEQ_PUT_HEX_FIELD(s, iter->ts);
		if (trace_seq_has_overflowed(s))
			return TRACE_TYPE_PARTIAL_LINE;
	}

	event = ftrace_find_event(entry->type);
	if (event) {
		enum print_line_t ret = event->funcs->hex(iter, 0, event);
		if (ret != TRACE_TYPE_HANDLED)
			return ret;
	}

	SEQ_PUT_FIELD(s, newline);

	return trace_handle_return(s);
}

Project: linux
File: trace.c

loff_t tracing_lseek(struct file *file, loff_t offset, int whence)
{
	int ret;

	if (file->f_mode & FMODE_READ)
		ret = seq_lseek(file, offset, whence);
	else
		file->f_pos = ret = 0;

	return ret;
}

Project: linux
File: trace.c

ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc)
{
	struct trace_event_call *call = &event_user_stack;
	struct ring_buffer_event *event;
	struct userstack_entry *entry;
	struct stack_trace trace;

	if (!(global_trace.trace_flags & TRACE_ITER_USERSTACKTRACE))
		return;

	/*
	 * NMIs can not handle page faults, even with fix ups.
	 * The save user stack can (and often does) fault.
	 */
	if (unlikely(in_nmi()))
		return;

	/*
	 * prevent recursion, since the user stack tracing may
	 * trigger other kernel events.
	 */
	preempt_disable();
	if (__this_cpu_read(user_stack_count))
		goto out;

	__this_cpu_inc(user_stack_count);

	event = __trace_buffer_lock_reserve(buffer, TRACE_USER_STACK,
					    sizeof(*entry), flags, pc);
	if (!event)
		goto out_drop_count;
	entry	= ring_buffer_event_data(event);

	entry->tgid		= current->tgid;
	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);
	if (!call_filter_check_discard(call, entry, buffer, event))
		__buffer_unlock_commit(buffer, event);

 out_drop_count:
	__this_cpu_dec(user_stack_count);
 out:
	preempt_enable();
}

Project: linux
File: trace.c

static inline void trace_create_eval_file(struct dentry *d_tracer) { }

Project: linux
File: trace.c

void ftrace_exports(struct ring_buffer_event *event)
{
	struct trace_export *export;

	preempt_disable_notrace();

	export = rcu_dereference_raw_notrace(ftrace_exports_list);
	while (export) {
		trace_process_export(export, event);
		export = rcu_dereference_raw_notrace(export->next);
	}

	preempt_enable_notrace();
}