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

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
......@@ -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();
......
......@@ -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 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp)
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);
......@@ -6153,11 +6122,11 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer)
&trace_clock_fops);
trace_create_file("tracing_on", 0644, d_tracer,
tr, &rb_simple_fops);
tr, &rb_simple_fops);
#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);
......
......@@ -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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