Merge tag 'trace-v5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

fa1796a8 · Linus Torvalds <[email protected]> · 2022-06-23 12:24:49 -05:00

Pull tracing fixes from Steven Rostedt:

 - Check for NULL in kretprobe_dispatcher()

   NULL can now be passed in, make sure it can handle it

 - Clean up unneeded #endif #ifdef of the same preprocessor
   check in the middle of the block.

 - Comment clean up

 - Remove unneeded initialization of the "ret" variable in
   __trace_uprobe_create()

* tag 'trace-v5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing/uprobes: Remove unwanted initialization in __trace_uprobe_create()
  tracefs: Fix syntax errors in comments
  tracing: Simplify conditional compilation code in tracing_set_tracer()
  tracing/kprobes: Check whether get_kretprobe() returns NULL in kretprobe_dispatcher()

Commit: fa1796a835fc24eb8fb5d794512ec299dcd9f3fd
Parents: 16e4bce6 · 12c3e0c9

Merge commit. Changes below are compared with the first parent: 16e4bce6.

Changes

4 files changed · +11 −5

File	Status	Add	Del	Content
fs/tracefs/inode.c	modified	+1	−1	View file
kernel/trace/trace.c	modified	+0	−2	View file
kernel/trace/trace_kprobe.c	modified	+10	−1	View file
kernel/trace/trace_uprobe.c	modified	+0	−1	View file

fs/tracefs/inode.c

View file

diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c
index de72527..81d26ab 100644
--- a/fs/tracefs/inode.c
+++ b/fs/tracefs/inode.c
@@ -553,7 +553,7 @@ struct dentry *tracefs_create_dir(const char *name, struct dentry *parent)
  *
  * Only one instances directory is allowed.
  *
- * The instances directory is special as it allows for mkdir and rmdir to
+ * The instances directory is special as it allows for mkdir and rmdir
  * to be done by userspace. When a mkdir or rmdir is performed, the inode
  * locks are released and the methods passed in (@mkdir and @rmdir) are
  * called without locks and with the name of the directory being created

kernel/trace/trace.c

View file

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 2c95992..a8cfac0 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -6424,9 +6424,7 @@ int tracing_set_tracer(struct trace_array *tr, const char *buf)
 		synchronize_rcu();
 		free_snapshot(tr);
 	}
-#endif
 
-#ifdef CONFIG_TRACER_MAX_TRACE
 	if (t->use_max_tr && !had_max_tr) {
 		ret = tracing_alloc_snapshot_instance(tr);
 		if (ret < 0)

kernel/trace/trace_kprobe.c

View file

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 9350733..a245ea6 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1718,8 +1718,17 @@ static int
 kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
 {
 	struct kretprobe *rp = get_kretprobe(ri);
-	struct trace_kprobe *tk = container_of(rp, struct trace_kprobe, rp);
+	struct trace_kprobe *tk;
+
+	/*
+	 * There is a small chance that get_kretprobe(ri) returns NULL when
+	 * the kretprobe is unregister on another CPU between kretprobe's
+	 * trampoline_handler and this function.
+	 */
+	if (unlikely(!rp))
+		return 0;
 
+	tk = container_of(rp, struct trace_kprobe, rp);
 	raw_cpu_inc(*tk->nhit);
 
 	if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE))

kernel/trace/trace_uprobe.c

View file

diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 9711589..c3dc4f8 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -546,7 +546,6 @@ static int __trace_uprobe_create(int argc, const char **argv)
 	bool is_return = false;
 	int i, ret;
 
-	ret = 0;
 	ref_ctr_offset = 0;
 
 	switch (argv[0][0]) {