#include <linux/notifier.h>
#include <linux/irqflags.h>
#include <linux/debugfs.h>
+#include <linux/tracefs.h>
#include <linux/pagemap.h>
#include <linux/hardirq.h>
#include <linux/linkage.h>
#include <linux/splice.h>
#include <linux/kdebug.h>
#include <linux/string.h>
+#include <linux/mount.h>
#include <linux/rwsem.h>
#include <linux/slab.h>
#include <linux/ctype.h>
/* 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");
tr->current_trace = &nop_trace;
}
-static int tracing_set_tracer(struct trace_array *tr, const char *buf)
+static void update_tracer_options(struct trace_array *tr, struct tracer *t)
{
static struct trace_option_dentry *topts;
+
+ /* Only enable if the directory has been created already. */
+ if (!tr->dir)
+ return;
+
+ /* Currently, only the top instance has options */
+ if (!(tr->flags & TRACE_ARRAY_FL_GLOBAL))
+ return;
+
+ destroy_trace_option_files(topts);
+ topts = create_trace_option_files(tr, t);
+}
+
+static int tracing_set_tracer(struct trace_array *tr, const char *buf)
+{
struct tracer *t;
#ifdef CONFIG_TRACER_MAX_TRACE
bool had_max_tr;
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--;
free_snapshot(tr);
}
#endif
- /* Currently, only the top instance has options */
- if (tr->flags & TRACE_ARRAY_FL_GLOBAL) {
- destroy_trace_option_files(topts);
- topts = create_trace_option_files(tr, t);
- }
+ update_tracer_options(tr, t);
#ifdef CONFIG_TRACER_MAX_TRACE
if (t->use_max_tr && !had_max_tr) {
}
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) {
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 (WARN_ON(!tr->dir))
+ return ERR_PTR(-ENODEV);
+ /* Top directory uses NULL as the parent */
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 NULL;
+ /* All sub buffers have a descriptor */
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);
+ tr->percpu_dir = tracefs_create_dir("per_cpu", d_tracer);
WARN_ONCE(!tr->percpu_dir,
- "Could not create debugfs directory 'per_cpu/%d'\n", cpu);
+ "Could not create tracefs directory 'per_cpu/%d'\n", cpu);
return tr->percpu_dir;
}
}
static void
-tracing_init_debugfs_percpu(struct trace_array *tr, long cpu)
+tracing_init_tracefs_percpu(struct trace_array *tr, long cpu)
{
struct dentry *d_percpu = tracing_dentry_percpu(tr, cpu);
struct dentry *d_cpu;
return;
snprintf(cpu_dir, 30, "cpu%ld", cpu);
- d_cpu = debugfs_create_dir(cpu_dir, d_percpu);
+ d_cpu = tracefs_create_dir(cpu_dir, d_percpu);
if (!d_cpu) {
- pr_warning("Could not create debugfs '%s' entry\n", cpu_dir);
+ pr_warning("Could not create tracefs '%s' entry\n", cpu_dir);
return;
}
{
struct dentry *ret;
- ret = debugfs_create_file(name, mode, parent, data, fops);
+ ret = tracefs_create_file(name, mode, parent, data, fops);
if (!ret)
- pr_warning("Could not create debugfs '%s' entry\n", name);
+ pr_warning("Could not create tracefs '%s' entry\n", name);
return ret;
}
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);
+ tr->options = tracefs_create_dir("options", d_tracer);
if (!tr->options) {
- pr_warning("Could not create debugfs directory 'options'\n");
+ pr_warning("Could not create tracefs directory 'options'\n");
return NULL;
}
return;
for (cnt = 0; topts[cnt].opt; cnt++)
- debugfs_remove(topts[cnt].entry);
+ tracefs_remove(topts[cnt].entry);
kfree(topts);
}
struct dentry *trace_instance_dir;
static void
-init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer);
+init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer);
static int
allocate_trace_buffer(struct trace_array *tr, struct trace_buffer *buf, int size)
#endif
}
-static int new_instance_create(const char *name)
+static int instance_mkdir(const char *name)
{
struct trace_array *tr;
int ret;
if (allocate_trace_buffers(tr, trace_buf_size) < 0)
goto out_free_tr;
- tr->dir = debugfs_create_dir(name, trace_instance_dir);
+ 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) {
- debugfs_remove_recursive(tr->dir);
+ tracefs_remove_recursive(tr->dir);
goto out_free_tr;
}
- init_tracer_debugfs(tr, tr->dir);
+ init_tracer_tracefs(tr, tr->dir);
list_add(&tr->list, &ftrace_trace_arrays);
}
-static int instance_delete(const char *name)
+static int instance_rmdir(const char *name)
{
struct trace_array *tr;
int found = 0;
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);
return ret;
}
-static int instance_mkdir (struct inode *inode, struct dentry *dentry, umode_t mode)
-{
- struct dentry *parent;
- int ret;
-
- /* Paranoid: Make sure the parent is the "instances" directory */
- parent = hlist_entry(inode->i_dentry.first, struct dentry, d_u.d_alias);
- if (WARN_ON_ONCE(parent != trace_instance_dir))
- return -ENOENT;
-
- /*
- * The inode mutex is locked, but debugfs_create_dir() will also
- * take the mutex. As the instances directory can not be destroyed
- * or changed in any other way, it is safe to unlock it, and
- * let the dentry try. If two users try to make the same dir at
- * the same time, then the new_instance_create() will determine the
- * winner.
- */
- mutex_unlock(&inode->i_mutex);
-
- ret = new_instance_create(dentry->d_iname);
-
- mutex_lock(&inode->i_mutex);
-
- return ret;
-}
-
-static int instance_rmdir(struct inode *inode, struct dentry *dentry)
-{
- struct dentry *parent;
- int ret;
-
- /* Paranoid: Make sure the parent is the "instances" directory */
- parent = hlist_entry(inode->i_dentry.first, struct dentry, d_u.d_alias);
- if (WARN_ON_ONCE(parent != trace_instance_dir))
- return -ENOENT;
-
- /* The caller did a dget() on dentry */
- mutex_unlock(&dentry->d_inode->i_mutex);
-
- /*
- * The inode mutex is locked, but debugfs_create_dir() will also
- * take the mutex. As the instances directory can not be destroyed
- * or changed in any other way, it is safe to unlock it, and
- * let the dentry try. If two users try to make the same dir at
- * the same time, then the instance_delete() will determine the
- * winner.
- */
- mutex_unlock(&inode->i_mutex);
-
- ret = instance_delete(dentry->d_iname);
-
- mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT);
- mutex_lock(&dentry->d_inode->i_mutex);
-
- return ret;
-}
-
-static const struct inode_operations instance_dir_inode_operations = {
- .lookup = simple_lookup,
- .mkdir = instance_mkdir,
- .rmdir = instance_rmdir,
-};
-
static __init void create_trace_instances(struct dentry *d_tracer)
{
- trace_instance_dir = debugfs_create_dir("instances", d_tracer);
+ trace_instance_dir = tracefs_create_instance_dir("instances", d_tracer,
+ instance_mkdir,
+ instance_rmdir);
if (WARN_ON(!trace_instance_dir))
return;
-
- /* Hijack the dir inode operations, to allow mkdir */
- trace_instance_dir->d_inode->i_op = &instance_dir_inode_operations;
}
static void
-init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer)
+init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer)
{
int cpu;
#endif
for_each_tracing_cpu(cpu)
- tracing_init_debugfs_percpu(tr, cpu);
+ tracing_init_tracefs_percpu(tr, cpu);
+
+}
+
+static struct vfsmount *trace_automount(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_kern_mount(type, 0, "tracefs", NULL);
+ put_filesystem(type);
+ if (IS_ERR(mnt))
+ return NULL;
+ mntget(mnt);
+
+ return mnt;
+}
+/**
+ * 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;
+
+ /* The top level trace array uses NULL as parent */
+ if (tr->dir)
+ return NULL;
+
+ if (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;
}
-static __init int tracer_init_debugfs(void)
+static __init int tracer_init_tracefs(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);
+ init_tracer_tracefs(&global_trace, d_tracer);
trace_create_file("tracing_thresh", 0644, d_tracer,
&global_trace, &tracing_thresh_fops);
create_trace_options_dir(&global_trace);
+ /* If the tracer was started via cmdline, create options for it here */
+ if (global_trace.current_trace != &nop_trace)
+ update_tracer_options(&global_trace, global_trace.current_trace);
+
return 0;
}
int ring_buf_size;
int ret = -ENOMEM;
-
if (!alloc_cpumask_var(&tracing_buffer_mask, GFP_KERNEL))
goto out;
tracepoint_printk = 0;
}
tracer_alloc_buffers();
- init_ftrace_syscalls();
trace_event_init();
}
return 0;
}
-fs_initcall(tracer_init_debugfs);
+fs_initcall(tracer_init_tracefs);
late_initcall(clear_boot_tracer);
git.openpandora.org / pandora-kernel.git / blobdiff