[PATCH v2 5.10 1/2] tracing/mmiotrace: Remove reference to unused per CPU data pointer

From: Alexander Martyniuk

Date: Mon Sep 07 2026 - 11:24:04 EST


From: Steven Rostedt <rostedt@xxxxxxxxxxx>

commit 6936298393d8d8bc3cec6b704f6a774162cf9bd3 upstream.

The mmiotracer referenced the per CPU array_buffer->data descriptor but
never actually used it. Remove the references to it.

Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/20250505212234.696945463@xxxxxxxxxxx
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
Signed-off-by: Alexander Martyniuk <alexevgmart@xxxxxxxxx>
---
Backport fix for CVE-2026-80689
kernel/trace/trace_mmiotrace.c | 12 ++----------
1 file changed, 2 insertions(+), 10 deletions(-)

diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
index e8ae2d92a678..55ba76bea98b 100644
--- a/kernel/trace/trace_mmiotrace.c
+++ b/kernel/trace/trace_mmiotrace.c
@@ -294,7 +294,6 @@ __init static int init_mmio_trace(void)
device_initcall(init_mmio_trace);

static void __trace_mmiotrace_rw(struct trace_array *tr,
- struct trace_array_cpu *data,
struct mmiotrace_rw *rw)
{
struct trace_event_call *call = &event_mmiotrace_rw;
@@ -319,12 +318,10 @@ static void __trace_mmiotrace_rw(struct trace_array *tr,
void mmio_trace_rw(struct mmiotrace_rw *rw)
{
struct trace_array *tr = mmio_trace_array;
- struct trace_array_cpu *data = per_cpu_ptr(tr->array_buffer.data, smp_processor_id());
- __trace_mmiotrace_rw(tr, data, rw);
+ __trace_mmiotrace_rw(tr, rw);
}

static void __trace_mmiotrace_map(struct trace_array *tr,
- struct trace_array_cpu *data,
struct mmiotrace_map *map)
{
struct trace_event_call *call = &event_mmiotrace_map;
@@ -349,12 +346,7 @@ static void __trace_mmiotrace_map(struct trace_array *tr,
void mmio_trace_mapping(struct mmiotrace_map *map)
{
struct trace_array *tr = mmio_trace_array;
- struct trace_array_cpu *data;
-
- preempt_disable();
- data = per_cpu_ptr(tr->array_buffer.data, smp_processor_id());
- __trace_mmiotrace_map(tr, data, map);
- preempt_enable();
+ __trace_mmiotrace_map(tr, map);
}

int mmio_trace_printk(const char *fmt, va_list args)
--
2.43.0