Linus,

Fixes for function graph:

- Fix missing mutex unlock in error path of register_ftrace_graph()

  A previous fix added a return on an error path and forgot to unlock the
  mutex. Instead of dealing with error paths, use guard(mutex) as the mutex
  is just released at the exit of the function anyway. Other functions
  in this file should be updated with this, but that's a cleanup and not
  a fix.

- Change cpuhp setup name to be consistent with other cpuhp states

  The same fix that the above patch fixes added a cpuhp_setup_state() call
  with the name of "fgraph_idle_init". I was informed that it should instead
  be something like: "fgraph:online". Update that too.


Please pull the latest ftrace-v6.12-rc4 tree, which can be found at:


  git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git
ftrace-v6.12-rc4

Tag SHA1: 8f6be7ca396ba3c46995234d3b17f61bb99a3a20
Head SHA1: a574e7f80e86c740e241c762923f50077b2c2a30


Li Huafei (1):
      fgraph: Fix missing unlock in register_ftrace_graph()

Steven Rostedt (1):
      fgraph: Change the name of cpuhp state to "fgraph:online"

----
 kernel/trace/fgraph.c | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)
---------------------------
diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
index 41e7a15dcb50..69e226a48daa 100644
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -1252,10 +1252,10 @@ int register_ftrace_graph(struct fgraph_ops *gops)
 	int ret = 0;
 	int i = -1;
 
-	mutex_lock(&ftrace_lock);
+	guard(mutex)(&ftrace_lock);
 
 	if (!fgraph_initialized) {
-		ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "fgraph_idle_init",
+		ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "fgraph:online",
 					fgraph_cpu_init, NULL);
 		if (ret < 0) {
 			pr_warn("fgraph: Error to init cpu hotplug support\n");
@@ -1273,10 +1273,8 @@ int register_ftrace_graph(struct fgraph_ops *gops)
 	}
 
 	i = fgraph_lru_alloc_index();
-	if (i < 0 || WARN_ON_ONCE(fgraph_array[i] != &fgraph_stub)) {
-		ret = -ENOSPC;
-		goto out;
-	}
+	if (i < 0 || WARN_ON_ONCE(fgraph_array[i] != &fgraph_stub))
+		return -ENOSPC;
 	gops->idx = i;
 
 	ftrace_graph_active++;
@@ -1313,8 +1311,6 @@ int register_ftrace_graph(struct fgraph_ops *gops)
 		gops->saved_func = NULL;
 		fgraph_lru_release_index(i);
 	}
-out:
-	mutex_unlock(&ftrace_lock);
 	return ret;
 }

The pull request you sent on Sat, 26 Oct 2024 03:45:06 -0400:

> git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git ftrace-v6.12-rc4

has been merged into torvalds/linux.git:
https://git.kernel.org/torvalds/c/f69a1accfe2e2ee2c43096abd9080b1fdb0c894d

Thank you!

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