/* trace_printk() is for debug use only. Don't use it in production. */
- pr_warning("\n**********************************************************\n");
+ pr_warning("\n");
+ pr_warning("**********************************************************\n");
pr_warning("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
pr_warning("** **\n");
pr_warning("** trace_printk() being used. Allocating extra memory. **\n");
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--;
}
trace_seq_init(&iter->seq);
-
- /*
- * We make a copy of the current tracer to avoid concurrent
- * changes on it while we are reading.
- */
- iter->trace = kmalloc(sizeof(*iter->trace), GFP_KERNEL);
- if (!iter->trace) {
- ret = -ENOMEM;
- goto fail;
- }
- *iter->trace = *tr->current_trace;
+ iter->trace = tr->current_trace;
if (!alloc_cpumask_var(&iter->started, GFP_KERNEL)) {
ret = -ENOMEM;
iter->trace->pipe_open(iter);
nonseekable_open(inode, filp);
+
+ tr->current_trace->ref++;
out:
mutex_unlock(&trace_types_lock);
return ret;
mutex_lock(&trace_types_lock);
+ tr->current_trace->ref--;
+
if (iter->trace->pipe_close)
iter->trace->pipe_close(iter);
free_cpumask_var(iter->started);
mutex_destroy(&iter->mutex);
- kfree(iter->trace);
kfree(iter);
trace_array_put(tr);
return trace_poll(iter, filp, poll_table);
}
-/* Must be called with trace_types_lock mutex held. */
+/* Must be called with iter->mutex held. */
static int tracing_wait_pipe(struct file *filp)
{
struct trace_iterator *iter = filp->private_data;
size_t cnt, loff_t *ppos)
{
struct trace_iterator *iter = filp->private_data;
- struct trace_array *tr = iter->tr;
ssize_t sret;
/* return any leftover data */
trace_seq_init(&iter->seq);
- /* copy the tracer to avoid using a global lock all around */
- mutex_lock(&trace_types_lock);
- if (unlikely(iter->trace->name != tr->current_trace->name))
- *iter->trace = *tr->current_trace;
- mutex_unlock(&trace_types_lock);
-
/*
* Avoid more than one consumer on a single file descriptor
* This is just a matter of traces coherency, the ring buffer itself
.ops = &tracing_pipe_buf_ops,
.spd_release = tracing_spd_release_pipe,
};
- struct trace_array *tr = iter->tr;
ssize_t ret;
size_t rem;
unsigned int i;
if (splice_grow_spd(pipe, &spd))
return -ENOMEM;
- /* copy the tracer to avoid using a global lock all around */
- mutex_lock(&trace_types_lock);
- if (unlikely(iter->trace->name != tr->current_trace->name))
- *iter->trace = *tr->current_trace;
- mutex_unlock(&trace_types_lock);
-
mutex_lock(&iter->mutex);
if (iter->trace->splice_read) {
*fpos += written;
out_unlock:
- for (i = 0; i < nr_pages; i++){
+ for (i = nr_pages - 1; i >= 0; i--) {
kunmap_atomic(map_page[i]);
put_page(pages[i]);
}
filp->private_data = info;
+ tr->current_trace->ref++;
+
mutex_unlock(&trace_types_lock);
ret = nonseekable_open(inode, filp);
if (!count)
return 0;
- mutex_lock(&trace_types_lock);
-
#ifdef CONFIG_TRACER_MAX_TRACE
- if (iter->snapshot && iter->tr->current_trace->use_max_tr) {
- size = -EBUSY;
- goto out_unlock;
- }
+ 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);
- size = -ENOMEM;
if (!info->spare)
- goto out_unlock;
+ return -ENOMEM;
/* Do we have previous read data to read? */
if (info->read < PAGE_SIZE)
if (ret < 0) {
if (trace_empty(iter)) {
- if ((filp->f_flags & O_NONBLOCK)) {
- size = -EAGAIN;
- goto out_unlock;
- }
- mutex_unlock(&trace_types_lock);
+ if ((filp->f_flags & O_NONBLOCK))
+ return -EAGAIN;
+
ret = wait_on_pipe(iter, false);
- mutex_lock(&trace_types_lock);
- if (ret) {
- size = ret;
- goto out_unlock;
- }
+ if (ret)
+ return ret;
+
goto again;
}
- size = 0;
- goto out_unlock;
+ return 0;
}
info->read = 0;
size = count;
ret = copy_to_user(ubuf, info->spare + info->read, size);
- if (ret == size) {
- size = -EFAULT;
- goto out_unlock;
- }
+ if (ret == size)
+ return -EFAULT;
+
size -= ret;
*ppos += size;
info->read += size;
- out_unlock:
- mutex_unlock(&trace_types_lock);
-
return size;
}
mutex_lock(&trace_types_lock);
+ iter->tr->current_trace->ref--;
+
__trace_array_put(iter->tr);
if (info->spare)
int entries, size, i;
ssize_t ret = 0;
- mutex_lock(&trace_types_lock);
-
#ifdef CONFIG_TRACER_MAX_TRACE
- if (iter->snapshot && iter->tr->current_trace->use_max_tr) {
- ret = -EBUSY;
- goto out;
- }
+ if (iter->snapshot && iter->tr->current_trace->use_max_tr)
+ return -EBUSY;
#endif
- if (splice_grow_spd(pipe, &spd)) {
- ret = -ENOMEM;
- goto out;
- }
+ if (splice_grow_spd(pipe, &spd))
+ return -ENOMEM;
- if (*ppos & (PAGE_SIZE - 1)) {
- ret = -EINVAL;
- goto out;
- }
+ if (*ppos & (PAGE_SIZE - 1))
+ return -EINVAL;
if (len & (PAGE_SIZE - 1)) {
- if (len < PAGE_SIZE) {
- ret = -EINVAL;
- goto out;
- }
+ if (len < PAGE_SIZE)
+ return -EINVAL;
len &= PAGE_MASK;
}
/* did we read anything? */
if (!spd.nr_pages) {
if (ret)
- goto out;
+ return ret;
+
+ if ((file->f_flags & O_NONBLOCK) || (flags & SPLICE_F_NONBLOCK))
+ return -EAGAIN;
- if ((file->f_flags & O_NONBLOCK) || (flags & SPLICE_F_NONBLOCK)) {
- ret = -EAGAIN;
- goto out;
- }
- mutex_unlock(&trace_types_lock);
ret = wait_on_pipe(iter, true);
- mutex_lock(&trace_types_lock);
if (ret)
- goto out;
+ return ret;
goto again;
}
ret = splice_to_pipe(pipe, &spd);
splice_shrink_spd(&spd);
-out:
- mutex_unlock(&trace_types_lock);
return ret;
}
static inline __init int register_snapshot_cmd(void) { return 0; }
#endif /* defined(CONFIG_TRACER_SNAPSHOT) && defined(CONFIG_DYNAMIC_FTRACE) */
-struct dentry *tracing_init_dentry_tr(struct trace_array *tr)
+static struct dentry *tracing_get_dentry(struct trace_array *tr)
{
- if (tr->dir)
- return tr->dir;
-
- if (!debugfs_initialized())
- return NULL;
-
- if (tr->flags & TRACE_ARRAY_FL_GLOBAL)
- tr->dir = debugfs_create_dir("tracing", NULL);
-
- if (!tr->dir)
- pr_warn_once("Could not create debugfs directory 'tracing'\n");
-
return tr->dir;
}
-struct dentry *tracing_init_dentry(void)
-{
- return tracing_init_dentry_tr(&global_trace);
-}
-
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_init_dentry_tr(tr);
- if (!d_tracer)
+ d_tracer = tracing_get_dentry(tr);
+ if (IS_ERR(d_tracer))
return NULL;
tr->percpu_dir = debugfs_create_dir("per_cpu", d_tracer);
if (tr->options)
return tr->options;
- d_tracer = tracing_init_dentry_tr(tr);
- if (!d_tracer)
+ d_tracer = tracing_get_dentry(tr);
+ if (IS_ERR(d_tracer))
return NULL;
tr->options = debugfs_create_dir("options", d_tracer);
goto out_unlock;
ret = -EBUSY;
- if (tr->ref)
+ if (tr->ref || (tr->current_trace && tr->current_trace->ref))
goto out_unlock;
list_del(&tr->list);
}
+/**
+ * tracing_init_dentry - initialize top level trace array
+ *
+ * This is called when creating files or directories in the tracing
+ * directory. It is called via fs_initcall() by any of the boot up code
+ * and expects to return the dentry of the top level tracing directory.
+ */
+struct dentry *tracing_init_dentry(void)
+{
+ struct trace_array *tr = &global_trace;
+
+ if (tr->dir)
+ return tr->dir;
+
+ if (WARN_ON(!debugfs_initialized()))
+ return ERR_PTR(-ENODEV);
+
+ tr->dir = debugfs_create_dir("tracing", NULL);
+
+ if (!tr->dir) {
+ pr_warn_once("Could not create debugfs directory 'tracing'\n");
+ return ERR_PTR(-ENOMEM);
+ }
+
+ return tr->dir;
+}
+
static __init int tracer_init_debugfs(void)
{
struct dentry *d_tracer;
trace_access_lock_init();
d_tracer = tracing_init_dentry();
- if (!d_tracer)
+ if (IS_ERR(d_tracer))
return 0;
init_tracer_debugfs(&global_trace, d_tracer);
int ring_buf_size;
int ret = -ENOMEM;
-
if (!alloc_cpumask_var(&tracing_buffer_mask, GFP_KERNEL))
goto out;
projects / linux-drm-fsl-dcu.git / blobdiff