Merge tag 'trace-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "This pull request has a lot of work done.  The main thing is the
  changes to the ftrace function callback infrastructure.  It's
  introducing a way to allow different functions to call directly
  different trampolines instead of all calling the same "mcount" one.

  The only user of this for now is the function graph tracer, which
  always had a different trampoline, but the function tracer trampoline
  was called and did basically nothing, and then the function graph
  tracer trampoline was called.  The difference now, is that the
  function graph tracer trampoline can be called directly if a function
  is only being traced by the function graph trampoline.  If function
  tracing is also happening on the same function, the old way is still
  done.

  The accounting for this takes up more memory when function graph
  tracing is activated, as it needs to keep track of which functions it
  uses.  I have a new way that wont take as much memory, but it's not
  ready yet for this merge window, and will have to wait for the next
  one.

  Another big change was the removal of the ftrace_start/stop() calls
  that were used by the suspend/resume code that stopped function
  tracing when entering into suspend and resume paths.  The stop of
  ftrace was done because there was some function that would crash the
  system if one called smp_processor_id()! The stop/start was a big
  hammer to solve the issue at the time, which was when ftrace was first
  introduced into Linux.  Now ftrace has better infrastructure to debug
  such issues, and I found the problem function and labeled it with
  "notrace" and function tracing can now safely be activated all the way
  down into the guts of suspend and resume

  Other changes include clean ups of uprobe code, clean up of the
  trace_seq() code, and other various small fixes and clean ups to
  ftrace and tracing"

* tag 'trace-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (57 commits)
  ftrace: Add warning if tramp hash does not match nr_trampolines
  ftrace: Fix trampoline hash update check on rec->flags
  ring-buffer: Use rb_page_size() instead of open coded head_page size
  ftrace: Rename ftrace_ops field from trampolines to nr_trampolines
  tracing: Convert local function_graph functions to static
  ftrace: Do not copy old hash when resetting
  tracing: let user specify tracing_thresh after selecting function_graph
  ring-buffer: Always run per-cpu ring buffer resize with schedule_work_on()
  tracing: Remove function_trace_stop and HAVE_FUNCTION_TRACE_MCOUNT_TEST
  s390/ftrace: remove check of obsolete variable function_trace_stop
  arm64, ftrace: Remove check of obsolete variable function_trace_stop
  Blackfin: ftrace: Remove check of obsolete variable function_trace_stop
  metag: ftrace: Remove check of obsolete variable function_trace_stop
  microblaze: ftrace: Remove check of obsolete variable function_trace_stop
  MIPS: ftrace: Remove check of obsolete variable function_trace_stop
  parisc: ftrace: Remove check of obsolete variable function_trace_stop
  sh: ftrace: Remove check of obsolete variable function_trace_stop
  sparc64,ftrace: Remove check of obsolete variable function_trace_stop
  tile: ftrace: Remove check of obsolete variable function_trace_stop
  ftrace: x86: Remove check of obsolete variable function_trace_stop
  ...

1 files changed, 61 insertions, 35 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 291397e66669..8bb80fe08767 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -937,30 +937,6 @@ out:
         return ret;
 }
 
-ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt)
-{
-        int len;
-        int ret;
-
-        if (!cnt)
-                return 0;
-
-        if (s->len <= s->readpos)
-                return -EBUSY;
-
-        len = s->len - s->readpos;
-        if (cnt > len)
-                cnt = len;
-        ret = copy_to_user(ubuf, s->buffer + s->readpos, cnt);
-        if (ret == cnt)
-                return -EFAULT;
-
-        cnt -= ret;
-
-        s->readpos += cnt;
-        return cnt;
-}
-
 static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt)
 {
         int len;
@@ -3699,6 +3675,7 @@ static const char readme_msg[] =
 #endif
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
         "  set_graph_function\t- Trace the nested calls of a function (function_graph)\n"
+        "  set_graph_notrace\t- Do not trace the nested calls of a function (function_graph)\n"
         "  max_graph_depth\t- Trace a limited depth of nested calls (0 is unlimited)\n"
 #endif
 #ifdef CONFIG_TRACER_SNAPSHOT
@@ -4238,10 +4215,9 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf,
 }
 
 static ssize_t
-tracing_max_lat_read(struct file *filp, char __user *ubuf,
-                     size_t cnt, loff_t *ppos)
+tracing_nsecs_read(unsigned long *ptr, char __user *ubuf,
+                   size_t cnt, loff_t *ppos)
 {
-        unsigned long *ptr = filp->private_data;
         char buf[64];
         int r;
 
@@ -4253,10 +4229,9 @@ tracing_max_lat_read(struct file *filp, char __user *ubuf,
 }
 
 static ssize_t
-tracing_max_lat_write(struct file *filp, const char __user *ubuf,
-                      size_t cnt, loff_t *ppos)
+tracing_nsecs_write(unsigned long *ptr, const char __user *ubuf,
+                    size_t cnt, loff_t *ppos)
 {
-        unsigned long *ptr = filp->private_data;
         unsigned long val;
         int ret;
 
@@ -4269,6 +4244,52 @@ tracing_max_lat_write(struct file *filp, const char __user *ubuf,
         return cnt;
 }
 
+static ssize_t
+tracing_thresh_read(struct file *filp, char __user *ubuf,
+                    size_t cnt, loff_t *ppos)
+{
+        return tracing_nsecs_read(&tracing_thresh, ubuf, cnt, ppos);
+}
+
+static ssize_t
+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;
+}
+
+static ssize_t
+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);
+}
+
+static ssize_t
+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);
+}
+
 static int tracing_open_pipe(struct inode *inode, struct file *filp)
 {
         struct trace_array *tr = inode->i_private;
@@ -5170,6 +5191,13 @@ static int snapshot_raw_open(struct inode *inode, struct file *filp)
 #endif /* CONFIG_TRACER_SNAPSHOT */
 
 
+static const struct file_operations tracing_thresh_fops = {
+        .open           = tracing_open_generic,
+        .read           = tracing_thresh_read,
+        .write          = tracing_thresh_write,
+        .llseek         = generic_file_llseek,
+};
+
 static const struct file_operations tracing_max_lat_fops = {
         .open           = tracing_open_generic,
         .read           = tracing_max_lat_read,
@@ -6107,10 +6135,8 @@ destroy_trace_option_files(struct trace_option_dentry *topts)
         if (!topts)
                 return;
 
-        for (cnt = 0; topts[cnt].opt; cnt++) {
-                if (topts[cnt].entry)
-                        debugfs_remove(topts[cnt].entry);
-        }
+        for (cnt = 0; topts[cnt].opt; cnt++)
+                debugfs_remove(topts[cnt].entry);
 
         kfree(topts);
 }
@@ -6533,7 +6559,7 @@ static __init int tracer_init_debugfs(void)
         init_tracer_debugfs(&global_trace, d_tracer);
 
         trace_create_file("tracing_thresh", 0644, d_tracer,
-                        &tracing_thresh, &tracing_max_lat_fops);
+                        &global_trace, &tracing_thresh_fops);
 
         trace_create_file("README", 0444, d_tracer,
                         NULL, &tracing_readme_fops);