From bce7698e2e6565bb765bd0522337f29f5f312624 Mon Sep 17 00:00:00 2001 From: Haojie Li Date: Tue, 25 Aug 2026 18:08:45 +0800 Subject: drm/mediatek: Add missing IS_ERR check for ovl_adaptor platform device platform_device_register_data() can fail and return an ERR_PTR, but the return value is used without checking, leading to an invalid pointer being stored in ddp_comp[].dev and passed to component_match_add() and mtk_ddp_comp_init(), which could result in a kernel crash. Add an IS_ERR() check to jump to the error handling path on failure. Fixes: 0d9eee9118b7 ("drm/mediatek: Add drm ovl_adaptor sub driver for MT8195") Cc: stable@vger.kernel.org Signed-off-by: Haojie Li Reviewed-by: CK Hu Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20260825100845.438893-1-lihaojie@kylinos.cn/ Signed-off-by: Chun-Kuang Hu --- tools/tracing/rtla/example/timerlat_bpf_action.c | 16 +++++ tools/tracing/rtla/example/timerlat_load.py | 78 ++++++++++++++++++++++++ 2 files changed, 94 insertions(+) create mode 100644 tools/tracing/rtla/example/timerlat_bpf_action.c create mode 100644 tools/tracing/rtla/example/timerlat_load.py (limited to 'tools/tracing/rtla/example') diff --git a/tools/tracing/rtla/example/timerlat_bpf_action.c b/tools/tracing/rtla/example/timerlat_bpf_action.c new file mode 100644 index 000000000..ac1be049a --- /dev/null +++ b/tools/tracing/rtla/example/timerlat_bpf_action.c @@ -0,0 +1,16 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include + +char LICENSE[] SEC("license") = "GPL"; + +struct trace_event_raw_timerlat_sample { + unsigned long long timer_latency; +} __attribute__((preserve_access_index)); + +SEC("tp/timerlat_action") +int action_handler(struct trace_event_raw_timerlat_sample *tp_args) +{ + bpf_printk("Latency: %lld\n", tp_args->timer_latency); + return 0; +} diff --git a/tools/tracing/rtla/example/timerlat_load.py b/tools/tracing/rtla/example/timerlat_load.py new file mode 100644 index 000000000..a819c3588 --- /dev/null +++ b/tools/tracing/rtla/example/timerlat_load.py @@ -0,0 +1,78 @@ +#!/usr/bin/env python3 +# SPDX-License-Identifier: GPL-2.0-only +# +# Copyright (C) 2024 Red Hat, Inc. Daniel Bristot de Oliveira +# +# This is a sample code about how to use timerlat's timer by any workload +# so rtla can measure and provide auto-analysis for the overall latency (IOW +# the response time) for a task. +# +# Before running it, you need to dispatch timerlat with -U option in a terminal. +# Then # run this script pinned to a CPU on another terminal. For example: +# +# timerlat_load.py 1 -p 95 +# +# The "Timerlat IRQ" is the IRQ latency, The thread latency is the latency +# for the python process to get the CPU. The Ret from user Timer Latency is +# the overall latency. In other words, it is the response time for that +# activation. +# +# This is just an example, the load is reading 20MB of data from /dev/full +# It is in python because it is easy to read :-) + +import argparse +import sys +import os + +parser = argparse.ArgumentParser(description='user-space timerlat thread in Python') +parser.add_argument("cpu", type=int, help='CPU to run timerlat thread') +parser.add_argument("-p", "--prio", type=int, help='FIFO priority') +args = parser.parse_args() + +try: + affinity_mask = {args.cpu} + os.sched_setaffinity(0, affinity_mask) +except Exception as e: + print(f"Error setting affinity: {e}") + sys.exit(1) + +if args.prio: + try: + param = os.sched_param(args.prio) + os.sched_setscheduler(0, os.SCHED_FIFO, param) + except Exception as e: + print(f"Error setting priority: {e}") + sys.exit(1) + +try: + timerlat_path = f"/sys/kernel/tracing/osnoise/per_cpu/cpu{args.cpu}/timerlat_fd" + timerlat_fd = open(timerlat_path, 'r') +except PermissionError: + print("Permission denied. Please check your access rights.") + sys.exit(1) +except OSError: + print("Error opening timerlat fd, did you run timerlat -U?") + sys.exit(1) + +try: + data_fd = open("/dev/full", 'r') +except Exception as e: + print(f"Error opening data fd: {e}") + sys.exit(1) + +while True: + try: + timerlat_fd.read(1) + data_fd.read(20 * 1024 * 1024) + except KeyboardInterrupt: + print("Leaving") + break + except IOError as e: + print(f"I/O error occurred: {e}") + break + except Exception as e: + print(f"Unexpected error: {e}") + break + +timerlat_fd.close() +data_fd.close() -- cgit v1.3.1