Hi all, I've run into an issue in 6.3.0-rc1 that causes problems with ftrace and I've bisected it to this commit: commit 98c062e8245199fa9121141a0bf1035dc45ae90e (HEAD, refs/bisect/bad) Author: Philipp Jungkamp p.jungkamp@xxxxxxx Date: Fri Nov 25 00:38:38 2022 +0100 HID: hid-sensor-custom: Allow more custom iio sensors The known LUID table for established/known custom HID sensors was limited to sensors with "INTEL" as manufacturer. But some vendors such as Lenovo also include fairly standard iio sensors (e.g. ambient light) in their custom sensors. Expand the known custom sensors table by a tag used for the platform device name and match sensors based on the LUID as well as optionally on model and manufacturer properties. Signed-off-by: Philipp Jungkamp p.jungkamp@xxxxxxx Reviewed-by: Jonathan Cameron Jonathan.Cameron@xxxxxxxxxx Acked-by: Srinivas Pandruvada srinivas.pandruvada@xxxxxxxxxxxxxxx Signed-off-by: Jiri Kosina jkosina@xxxxxxx You're using raw data as part of the devname in the "real_usage" string, but it includes chars other than ASCII, and those chars end up being printed out in the ftrace log which is meant to be ASCII only. - /* HID-SENSOR-INT-REAL_USAGE_ID */ - dev_name = kasprintf(GFP_KERNEL, "HID-SENSOR-INT-%s", real_usage); + /* HID-SENSOR-TAG-REAL_USAGE_ID */ + dev_name = kasprintf(GFP_KERNEL, "HID-SENSOR-%s-%s", + match->tag, real_usage); My sleepgraph tool started to crash because it read these lines from ftrace: device_pm_callback_start: platform HID-SENSOR-INT-020b?.39.auto, parent: 001F:8087:0AC2.0003, [suspend] device_pm_callback_end: platform HID-SENSOR-INT-020b?.39.auto, err=0 The "HID-SENSOR-INT-020b?.39.auto" string includes a binary char that kills python3 code that loops through an ascii file as such: File "/usr/bin/sleepgraph", line 5579, in executeSuspend for line in fp: File "/usr/lib/python3.10/codecs.py", line 322, in decode (result, consumed) = self._buffer_decode(data, self.errors, final) UnicodeDecodeError: 'utf-8' codec can't decode byte 0xff in position 1568: invalid start byte I've updated sleepgraph to handle random non-ascii chars, but other tools may suffer the same fate. Can you rewrite this to ensure that no binary chars make it into the devname?