[for-next][PATCH 0/3] tracing: Updates for v7.3

[for-next][PATCH 0/3] tracing: Updates for v7.3

[Steven Rostedt]

  git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git
trace/for-next

Head SHA1: a8aaf7445bfcdb6e61ee4b8e4946d684c1b4a228


David Carlier (1):
      tracing: Report every TP_printk double dereference

Masami Hiramatsu (Google) (1):
      tracing/mmiotrace: Use trace_assign_type() in mmio_print_mark()

Steven Rostedt (1):
      tracing: Cleanup event_enable_trigger_parse() by using __free()

----
 kernel/trace/trace_events.c         |  2 ++
 kernel/trace/trace_events_trigger.c | 16 ++++++++--------
 kernel/trace/trace_mmiotrace.c      |  7 +++++--
 3 files changed, 15 insertions(+), 10 deletions(-)

[for-next][PATCH 1/3] tracing/mmiotrace: Use trace_assign_type() in mmio_print_mark()

[Steven Rostedt]

From: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>

In mmio_print_mark(), a raw C cast (struct print_entry *)entry is used to
obtain the print_entry pointer.

Use the standard trace_assign_type() macro instead, matching the usage in
mmio_print_rw() and mmio_print_map().

Link: https://patch.msgid.link/178524301013.56416.9116249028160618790.stgit@devnote2
Assisted-by: Antigravity:gemini-3.6-flash
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/trace_mmiotrace.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
index b88b8d9923ad..ebdba4f8d64f 100644
--- a/kernel/trace/trace_mmiotrace.c
+++ b/kernel/trace/trace_mmiotrace.c
@@ -243,13 +243,16 @@ static enum print_line_t mmio_print_map(struct trace_iterator *iter)
 static enum print_line_t mmio_print_mark(struct trace_iterator *iter)
 {
 	struct trace_entry *entry = iter->ent;
-	struct print_entry *print = (struct print_entry *)entry;
-	const char *msg		= print->buf;
+	struct print_entry *print;
+	const char *msg;
 	struct trace_seq *s	= &iter->seq;
 	unsigned long long t	= ns2usecs(iter->ts);
 	unsigned long usec_rem	= do_div(t, USEC_PER_SEC);
 	unsigned secs		= (unsigned long)t;
 
+	trace_assign_type(print, entry);
+	msg = print->buf;
+
 	/* The trailing newline must be in the message. */
 	trace_seq_printf(s, "MARK %u.%06lu %s", secs, usec_rem, msg);
 
-- 
2.53.0

[for-next][PATCH 2/3] tracing: Report every TP_printk double dereference

[Steven Rostedt]

From: David Carlier <devnexen@gmail.com>

WARN_ONCE() splats once per call site, so only the first offending event
registered is ever reported. The tree currently has six:
ice_{rx,tx}_dim_template, two hfi1 txq events, mtu3_ep and edma_log_io.
Whichever registers first hides the rest, and each has to be found again
on the next boot.

Add a pr_warn() next to the WARN_ONCE() so every offender is listed, the
same way test_event_printk() already pairs WARN_ON_ONCE() with pr_warn()
for unsafe %p* dereferences. The WARN_ONCE() stays so the condition still
fails tests and panics under panic_on_warn.

Link: https://patch.msgid.link/20260806215256.1680267-1-devnexen@gmail.com
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: David Carlier <devnexen@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/trace_events.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index a8590d2394e3..ce902482ec7c 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -415,6 +415,8 @@ static void test_double_dereference(const char *str, int len,
 		ptr += 5;
 		for (; ptr < end; ptr++) {
 			if (ptr[0] == '-' && ptr[1] == '>') {
+				pr_warn("TRACE EVENT ERROR: Event %s has double dereference in TP_printk: %.*s\n",
+					trace_event_name(call), len, str);
 				WARN_ONCE(1, "Event %s has double dereference in TP_printk: %.*s\n",
 					  trace_event_name(call), len, str);
 				return;
-- 
2.53.0

[for-next][PATCH 3/3] tracing: Cleanup event_enable_trigger_parse() by using __free()

[Steven Rostedt]

From: Steven Rostedt <rostedt@goodmis.org>

The enable_data variable gets freed on most error paths in
event_enable_trigger_parse(). Use free() to free it and just before
returning normally, call retain_and_null_ptr(enable_data) just before a
successful exit to keep it from being freed. On success, the enable_data
is assigned to the trigger_data->private_data field.

Also add a comment to why event_trigger_free(trigger_data) is being called
before a successful exit.

Link: https://patch.msgid.link/20260807113558.0ff14e96@gandalf.local.home
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/trace_events_trigger.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index ad83419cb420..149300cc5e8a 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -1753,7 +1753,7 @@ int event_enable_trigger_parse(struct event_command *cmd_ops,
 			       char *glob, char *cmd, char *param_and_filter)
 {
 	struct trace_event_file *event_enable_file;
-	struct enable_trigger_data *enable_data;
+	struct enable_trigger_data *enable_data __free(kfree) = NULL;
 	struct event_trigger_data *trigger_data;
 	struct trace_array *tr = file->tr;
 	char *param, *filter;
@@ -1803,17 +1803,13 @@ int event_enable_trigger_parse(struct event_command *cmd_ops,
 	enable_data->file = event_enable_file;
 
 	trigger_data = trigger_data_alloc(cmd_ops, cmd, param, enable_data);
-	if (!trigger_data) {
-		kfree(enable_data);
+	if (!trigger_data)
 		return ret;
-	}
 
 	if (remove) {
 		event_trigger_unregister(cmd_ops, file, glob+1, trigger_data);
 		kfree(trigger_data);
-		kfree(enable_data);
-		ret = 0;
-		return ret;
+		return 0;
 	}
 
 	/* Up the trigger_data count to make sure nothing frees it on failure */
@@ -1842,7 +1838,12 @@ int event_enable_trigger_parse(struct event_command *cmd_ops,
 	if (ret)
 		goto out_disable;
 
+	/* It's now safe to free the reference taken earlier */
 	event_trigger_free(trigger_data);
+
+	/* The enabled_data is assigned to trigger_data->private_data */
+	retain_and_null_ptr(enable_data);
+
 	return ret;
  out_disable:
 	trace_event_enable_disable(event_enable_file, 0, 1);
@@ -1851,7 +1852,6 @@ int event_enable_trigger_parse(struct event_command *cmd_ops,
  out_free:
 	event_trigger_reset_filter(cmd_ops, trigger_data);
 	event_trigger_free(trigger_data);
-	kfree(enable_data);
 
 	return ret;
 }
-- 
2.53.0