Commit 6803f37e authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'trace-fixes-3.11-rc2' of... 

Merge tag 'trace-fixes-3.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Oleg is working on fixing a very tight race between opening a event
  file and deleting that event at the same time (both must be done as
  root).

  I also found a bug while testing Oleg's patches which has to do with a
  race with kprobes using the function tracer.

  There's also a deadlock fix that was introduced with the previous
  fixes"

* tag 'trace-fixes-3.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Remove locking trace_types_lock from tracing_reset_all_online_cpus()
  ftrace: Add check for NULL regs if ops has SAVE_REGS set
  tracing: Kill trace_cpu struct/members
  tracing: Change tracing_fops/snapshot_fops to rely on tracing_get_cpu()
  tracing: Change tracing_entries_fops to rely on tracing_get_cpu()
  tracing: Change tracing_stats_fops to rely on tracing_get_cpu()
  tracing: Change tracing_buffers_fops to rely on tracing_get_cpu()
  tracing: Change tracing_pipe_fops() to rely on tracing_get_cpu()
  tracing: Introduce trace_create_cpu_file() and tracing_get_cpu()
parents 561d9e81 09d8091c

kernel/trace/ftrace.c

+14 −4
Original line number Diff line number Diff line
@@ -1441,12 +1441,22 @@ ftrace_hash_move(struct ftrace_ops *ops, int enable, 
 * the hashes are freed with call_rcu_sched().

 */

static int

ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip)

ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)

{

	struct ftrace_hash *filter_hash;

	struct ftrace_hash *notrace_hash;

	int ret;



#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS

	/*

	 * There's a small race when adding ops that the ftrace handler

	 * that wants regs, may be called without them. We can not

	 * allow that handler to be called if regs is NULL.

	 */

	if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS))

		return 0;

#endif



	filter_hash = rcu_dereference_raw_notrace(ops->filter_hash);

	notrace_hash = rcu_dereference_raw_notrace(ops->notrace_hash);
@@ -4218,7 +4228,7 @@ static inline void ftrace_startup_enable(int command) { } 
# define ftrace_shutdown_sysctl()	do { } while (0)



static inline int

ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip)

ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)

{

	return 1;

}
@@ -4241,7 +4251,7 @@ ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip, 
	do_for_each_ftrace_op(op, ftrace_control_list) {

		if (!(op->flags & FTRACE_OPS_FL_STUB) &&

		    !ftrace_function_local_disabled(op) &&

		    ftrace_ops_test(op, ip))

		    ftrace_ops_test(op, ip, regs))

			op->func(ip, parent_ip, op, regs);

	} while_for_each_ftrace_op(op);

	trace_recursion_clear(TRACE_CONTROL_BIT);
@@ -4274,7 +4284,7 @@ __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, 
	 */

	preempt_disable_notrace();

	do_for_each_ftrace_op(op, ftrace_ops_list) {

		if (ftrace_ops_test(op, ip))

		if (ftrace_ops_test(op, ip, regs))

			op->func(ip, parent_ip, op, regs);

	} while_for_each_ftrace_op(op);

	preempt_enable_notrace();

kernel/trace/trace.c

+81 −116
Original line number Diff line number Diff line
@@ -1224,18 +1224,17 @@ void tracing_reset_current(int cpu) 
	tracing_reset(&global_trace.trace_buffer, cpu);

}



/* Must have trace_types_lock held */

void tracing_reset_all_online_cpus(void)

{

	struct trace_array *tr;



	mutex_lock(&trace_types_lock);

	list_for_each_entry(tr, &ftrace_trace_arrays, list) {

		tracing_reset_online_cpus(&tr->trace_buffer);

#ifdef CONFIG_TRACER_MAX_TRACE

		tracing_reset_online_cpus(&tr->max_buffer);

#endif

	}

	mutex_unlock(&trace_types_lock);

}



#define SAVED_CMDLINES 128
@@ -2843,6 +2842,17 @@ static int s_show(struct seq_file *m, void *v) 
	return 0;

}



/*

 * Should be used after trace_array_get(), trace_types_lock

 * ensures that i_cdev was already initialized.

 */

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;

}



static const struct seq_operations tracer_seq_ops = {

	.start		= s_start,

	.next		= s_next,
@@ -2851,9 +2861,9 @@ static const struct seq_operations tracer_seq_ops = { 
};



static struct trace_iterator *

__tracing_open(struct trace_array *tr, struct trace_cpu *tc,

	       struct inode *inode, struct file *file, bool snapshot)

__tracing_open(struct inode *inode, struct file *file, bool snapshot)

{

	struct trace_array *tr = inode->i_private;

	struct trace_iterator *iter;

	int cpu;
@@ -2894,8 +2904,8 @@ __tracing_open(struct trace_array *tr, struct trace_cpu *tc, 
		iter->trace_buffer = &tr->trace_buffer;

	iter->snapshot = snapshot;

	iter->pos = -1;

	iter->cpu_file = tracing_get_cpu(inode);

	mutex_init(&iter->mutex);

	iter->cpu_file = tc->cpu;



	/* Notify the tracer early; before we stop tracing. */

	if (iter->trace && iter->trace->open)
@@ -2971,44 +2981,22 @@ static int tracing_open_generic_tr(struct inode *inode, struct file *filp) 
	filp->private_data = inode->i_private;



	return 0;

	

}



static int tracing_open_generic_tc(struct inode *inode, struct file *filp)

{

	struct trace_cpu *tc = inode->i_private;

	struct trace_array *tr = tc->tr;



	if (tracing_disabled)

		return -ENODEV;



	if (trace_array_get(tr) < 0)

		return -ENODEV;



	filp->private_data = inode->i_private;



	return 0;

	

}



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;

	struct trace_array *tr;

	int cpu;



	/* Writes do not use seq_file, need to grab tr from inode */

	if (!(file->f_mode & FMODE_READ)) {

		struct trace_cpu *tc = inode->i_private;



		trace_array_put(tc->tr);

		trace_array_put(tr);

		return 0;

	}



	/* Writes do not use seq_file */

	iter = m->private;

	tr = iter->tr;



	mutex_lock(&trace_types_lock);



	for_each_tracing_cpu(cpu) {
@@ -3044,15 +3032,6 @@ static int tracing_release_generic_tr(struct inode *inode, struct file *file) 
	return 0;

}



static int tracing_release_generic_tc(struct inode *inode, struct file *file)

{

	struct trace_cpu *tc = inode->i_private;

	struct trace_array *tr = tc->tr;



	trace_array_put(tr);

	return 0;

}



static int tracing_single_release_tr(struct inode *inode, struct file *file)

{

	struct trace_array *tr = inode->i_private;
@@ -3064,8 +3043,7 @@ static int tracing_single_release_tr(struct inode *inode, struct file *file) 


static int tracing_open(struct inode *inode, struct file *file)

{

	struct trace_cpu *tc = inode->i_private;

	struct trace_array *tr = tc->tr;

	struct trace_array *tr = inode->i_private;

	struct trace_iterator *iter;

	int ret = 0;
@@ -3073,16 +3051,17 @@ static int tracing_open(struct inode *inode, struct file *file) 
		return -ENODEV;



	/* If this file was open for write, then erase contents */

	if ((file->f_mode & FMODE_WRITE) &&

	    (file->f_flags & O_TRUNC)) {

		if (tc->cpu == RING_BUFFER_ALL_CPUS)

	if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {

		int cpu = tracing_get_cpu(inode);



		if (cpu == RING_BUFFER_ALL_CPUS)

			tracing_reset_online_cpus(&tr->trace_buffer);

		else

			tracing_reset(&tr->trace_buffer, tc->cpu);

			tracing_reset(&tr->trace_buffer, cpu);

	}



	if (file->f_mode & FMODE_READ) {

		iter = __tracing_open(tr, tc, inode, file, false);

		iter = __tracing_open(inode, file, false);

		if (IS_ERR(iter))

			ret = PTR_ERR(iter);

		else if (trace_flags & TRACE_ITER_LATENCY_FMT)
@@ -3948,8 +3927,7 @@ tracing_max_lat_write(struct file *filp, const char __user *ubuf, 


static int tracing_open_pipe(struct inode *inode, struct file *filp)

{

	struct trace_cpu *tc = inode->i_private;

	struct trace_array *tr = tc->tr;

	struct trace_array *tr = inode->i_private;

	struct trace_iterator *iter;

	int ret = 0;
@@ -3995,9 +3973,9 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp) 
	if (trace_clocks[tr->clock_id].in_ns)

		iter->iter_flags |= TRACE_FILE_TIME_IN_NS;



	iter->cpu_file = tc->cpu;

	iter->tr = tc->tr;

	iter->trace_buffer = &tc->tr->trace_buffer;

	iter->tr = tr;

	iter->trace_buffer = &tr->trace_buffer;

	iter->cpu_file = tracing_get_cpu(inode);

	mutex_init(&iter->mutex);

	filp->private_data = iter;
@@ -4020,8 +3998,7 @@ fail: 
static int tracing_release_pipe(struct inode *inode, struct file *file)

{

	struct trace_iterator *iter = file->private_data;

	struct trace_cpu *tc = inode->i_private;

	struct trace_array *tr = tc->tr;

	struct trace_array *tr = inode->i_private;



	mutex_lock(&trace_types_lock);
@@ -4374,15 +4351,16 @@ static ssize_t 
tracing_entries_read(struct file *filp, char __user *ubuf,

		     size_t cnt, loff_t *ppos)

{

	struct trace_cpu *tc = filp->private_data;

	struct trace_array *tr = tc->tr;

	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 (tc->cpu == RING_BUFFER_ALL_CPUS) {

	if (cpu == RING_BUFFER_ALL_CPUS) {

		int cpu, buf_size_same;

		unsigned long size;
@@ -4409,7 +4387,7 @@ tracing_entries_read(struct file *filp, char __user *ubuf, 
		} else

			r = sprintf(buf, "X\n");

	} else

		r = sprintf(buf, "%lu\n", per_cpu_ptr(tr->trace_buffer.data, tc->cpu)->entries >> 10);

		r = sprintf(buf, "%lu\n", per_cpu_ptr(tr->trace_buffer.data, cpu)->entries >> 10);



	mutex_unlock(&trace_types_lock);
@@ -4421,7 +4399,8 @@ static ssize_t 
tracing_entries_write(struct file *filp, const char __user *ubuf,

		      size_t cnt, loff_t *ppos)

{

	struct trace_cpu *tc = filp->private_data;

	struct inode *inode = file_inode(filp);

	struct trace_array *tr = inode->i_private;

	unsigned long val;

	int ret;
@@ -4435,8 +4414,7 @@ tracing_entries_write(struct file *filp, const char __user *ubuf, 


	/* value is in KB */

	val <<= 10;



	ret = tracing_resize_ring_buffer(tc->tr, val, tc->cpu);

	ret = tracing_resize_ring_buffer(tr, val, tracing_get_cpu(inode));

	if (ret < 0)

		return ret;
@@ -4697,8 +4675,7 @@ struct ftrace_buffer_info { 
#ifdef CONFIG_TRACER_SNAPSHOT

static int tracing_snapshot_open(struct inode *inode, struct file *file)

{

	struct trace_cpu *tc = inode->i_private;

	struct trace_array *tr = tc->tr;

	struct trace_array *tr = inode->i_private;

	struct trace_iterator *iter;

	struct seq_file *m;

	int ret = 0;
@@ -4707,7 +4684,7 @@ static int tracing_snapshot_open(struct inode *inode, struct file *file) 
		return -ENODEV;



	if (file->f_mode & FMODE_READ) {

		iter = __tracing_open(tr, tc, inode, file, true);

		iter = __tracing_open(inode, file, true);

		if (IS_ERR(iter))

			ret = PTR_ERR(iter);

	} else {
@@ -4724,8 +4701,8 @@ static int tracing_snapshot_open(struct inode *inode, struct file *file) 
		ret = 0;



		iter->tr = tr;

		iter->trace_buffer = &tc->tr->max_buffer;

		iter->cpu_file = tc->cpu;

		iter->trace_buffer = &tr->max_buffer;

		iter->cpu_file = tracing_get_cpu(inode);

		m->private = iter;

		file->private_data = m;

	}
@@ -4884,11 +4861,11 @@ static const struct file_operations tracing_pipe_fops = { 
};



static const struct file_operations tracing_entries_fops = {

	.open		= tracing_open_generic_tc,

	.open		= tracing_open_generic_tr,

	.read		= tracing_entries_read,

	.write		= tracing_entries_write,

	.llseek		= generic_file_llseek,

	.release	= tracing_release_generic_tc,

	.release	= tracing_release_generic_tr,

};



static const struct file_operations tracing_total_entries_fops = {
@@ -4940,8 +4917,7 @@ static const struct file_operations snapshot_raw_fops = { 


static int tracing_buffers_open(struct inode *inode, struct file *filp)

{

	struct trace_cpu *tc = inode->i_private;

	struct trace_array *tr = tc->tr;

	struct trace_array *tr = inode->i_private;

	struct ftrace_buffer_info *info;

	int ret;
@@ -4960,7 +4936,7 @@ static int tracing_buffers_open(struct inode *inode, struct file *filp) 
	mutex_lock(&trace_types_lock);



	info->iter.tr		= tr;

	info->iter.cpu_file	= tc->cpu;

	info->iter.cpu_file	= tracing_get_cpu(inode);

	info->iter.trace	= tr->current_trace;

	info->iter.trace_buffer = &tr->trace_buffer;

	info->spare		= NULL;
@@ -5277,14 +5253,14 @@ static ssize_t 
tracing_stats_read(struct file *filp, char __user *ubuf,

		   size_t count, loff_t *ppos)

{

	struct trace_cpu *tc = filp->private_data;

	struct trace_array *tr = tc->tr;

	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;

	int cpu = tc->cpu;



	s = kmalloc(sizeof(*s), GFP_KERNEL);

	if (!s)
@@ -5337,10 +5313,10 @@ tracing_stats_read(struct file *filp, char __user *ubuf, 
}



static const struct file_operations tracing_stats_fops = {

	.open		= tracing_open_generic_tc,

	.open		= tracing_open_generic_tr,

	.read		= tracing_stats_read,

	.llseek		= generic_file_llseek,

	.release	= tracing_release_generic_tc,

	.release	= tracing_release_generic_tr,

};



#ifdef CONFIG_DYNAMIC_FTRACE
@@ -5529,10 +5505,20 @@ static struct dentry *tracing_dentry_percpu(struct trace_array *tr, int cpu) 
	return tr->percpu_dir;

}



static struct dentry *

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() */

		ret->d_inode->i_cdev = (void *)(cpu + 1);

	return ret;

}



static void

tracing_init_debugfs_percpu(struct trace_array *tr, long cpu)

{

	struct trace_array_cpu *data = per_cpu_ptr(tr->trace_buffer.data, 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 */
@@ -5548,28 +5534,28 @@ tracing_init_debugfs_percpu(struct trace_array *tr, long cpu) 
	}



	/* per cpu trace_pipe */

	trace_create_file("trace_pipe", 0444, d_cpu,

			(void *)&data->trace_cpu, &tracing_pipe_fops);

	trace_create_cpu_file("trace_pipe", 0444, d_cpu,

				tr, cpu, &tracing_pipe_fops);



	/* per cpu trace */

	trace_create_file("trace", 0644, d_cpu,

			(void *)&data->trace_cpu, &tracing_fops);

	trace_create_cpu_file("trace", 0644, d_cpu,

				tr, cpu, &tracing_fops);



	trace_create_file("trace_pipe_raw", 0444, d_cpu,

			(void *)&data->trace_cpu, &tracing_buffers_fops);

	trace_create_cpu_file("trace_pipe_raw", 0444, d_cpu,

				tr, cpu, &tracing_buffers_fops);



	trace_create_file("stats", 0444, d_cpu,

			(void *)&data->trace_cpu, &tracing_stats_fops);

	trace_create_cpu_file("stats", 0444, d_cpu,

				tr, cpu, &tracing_stats_fops);



	trace_create_file("buffer_size_kb", 0444, d_cpu,

			(void *)&data->trace_cpu, &tracing_entries_fops);

	trace_create_cpu_file("buffer_size_kb", 0444, d_cpu,

				tr, cpu, &tracing_entries_fops);



#ifdef CONFIG_TRACER_SNAPSHOT

	trace_create_file("snapshot", 0644, d_cpu,

			  (void *)&data->trace_cpu, &snapshot_fops);

	trace_create_cpu_file("snapshot", 0644, d_cpu,

				tr, cpu, &snapshot_fops);



	trace_create_file("snapshot_raw", 0444, d_cpu,

			(void *)&data->trace_cpu, &snapshot_raw_fops);

	trace_create_cpu_file("snapshot_raw", 0444, d_cpu,

				tr, cpu, &snapshot_raw_fops);

#endif

}
@@ -5878,17 +5864,6 @@ struct dentry *trace_instance_dir; 
static void

init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer);



static void init_trace_buffers(struct trace_array *tr, struct trace_buffer *buf)

{

	int cpu;



	for_each_tracing_cpu(cpu) {

		memset(per_cpu_ptr(buf->data, cpu), 0, sizeof(struct trace_array_cpu));

		per_cpu_ptr(buf->data, cpu)->trace_cpu.cpu = cpu;

		per_cpu_ptr(buf->data, cpu)->trace_cpu.tr = tr;

	}

}



static int

allocate_trace_buffer(struct trace_array *tr, struct trace_buffer *buf, int size)

{
@@ -5906,8 +5881,6 @@ allocate_trace_buffer(struct trace_array *tr, struct trace_buffer *buf, int size 
		return -ENOMEM;

	}



	init_trace_buffers(tr, buf);



	/* Allocate the first page for all buffers */

	set_buffer_entries(&tr->trace_buffer,

			   ring_buffer_size(tr->trace_buffer.buffer, 0));
@@ -5974,10 +5947,6 @@ static int new_instance_create(const char *name) 
	if (allocate_trace_buffers(tr, trace_buf_size) < 0)

		goto out_free_tr;



	/* Holder for file callbacks */

	tr->trace_cpu.cpu = RING_BUFFER_ALL_CPUS;

	tr->trace_cpu.tr = tr;



	tr->dir = debugfs_create_dir(name, trace_instance_dir);

	if (!tr->dir)

		goto out_free_tr;
@@ -6132,13 +6101,13 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer) 
			  tr, &tracing_iter_fops);



	trace_create_file("trace", 0644, d_tracer,

			(void *)&tr->trace_cpu, &tracing_fops);

			  tr, &tracing_fops);



	trace_create_file("trace_pipe", 0444, d_tracer,

			(void *)&tr->trace_cpu, &tracing_pipe_fops);

			  tr, &tracing_pipe_fops);



	trace_create_file("buffer_size_kb", 0644, d_tracer,

			(void *)&tr->trace_cpu, &tracing_entries_fops);

			  tr, &tracing_entries_fops);



	trace_create_file("buffer_total_size_kb", 0444, d_tracer,

			  tr, &tracing_total_entries_fops);
@@ -6157,7 +6126,7 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer) 


#ifdef CONFIG_TRACER_SNAPSHOT

	trace_create_file("snapshot", 0644, d_tracer,

			  (void *)&tr->trace_cpu, &snapshot_fops);

			  tr, &snapshot_fops);

#endif



	for_each_tracing_cpu(cpu)
@@ -6451,10 +6420,6 @@ __init static int tracer_alloc_buffers(void) 


	global_trace.flags = TRACE_ARRAY_FL_GLOBAL;



	/* Holder for file callbacks */

	global_trace.trace_cpu.cpu = RING_BUFFER_ALL_CPUS;

	global_trace.trace_cpu.tr = &global_trace;



	INIT_LIST_HEAD(&global_trace.systems);

	INIT_LIST_HEAD(&global_trace.events);

	list_add(&global_trace.list, &ftrace_trace_arrays);

kernel/trace/trace.h

+0 −8
Original line number Diff line number Diff line
@@ -130,19 +130,12 @@ enum trace_flag_type { 


struct trace_array;



struct trace_cpu {

	struct trace_array	*tr;

	struct dentry		*dir;

	int			cpu;

};



/*

 * The CPU trace array - it consists of thousands of trace entries

 * plus some other descriptor data: (for example which task started

 * the trace, etc.)

 */

struct trace_array_cpu {

	struct trace_cpu	trace_cpu;

	atomic_t		disabled;

	void			*buffer_page;	/* ring buffer spare */
@@ -196,7 +189,6 @@ struct trace_array { 
	bool			allocated_snapshot;

#endif

	int			buffer_disabled;

	struct trace_cpu	trace_cpu;	/* place holder */

#ifdef CONFIG_FTRACE_SYSCALLS

	int			sys_refcount_enter;

	int			sys_refcount_exit;

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