From 6668ed271eaefaa63e686bdfbedaeb7b8e492722 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 4 Sep 2026 10:43:19 +0200 Subject: selftests/bpf: Reject graph kptr use after RCU unlock Add a sleepable verifier test that loads a graph-node local kptr in an explicit RCU read-side critical section, then passes its node to bpf_rbtree_remove() after the section ends. Before the verifier fix, the stale NON_OWN_REF flag makes the node look like a live borrowed reference and the program is accepted. After the fix, the pointer is demoted without NON_OWN_REF and the graph kfunc argument is rejected. Also exercise a graph kptr loaded while a spin lock provides implicit RCU protection. The pointer must be invalidated when the lock is released, which guards the required ordering between non-owning-reference invalidation and RCU demotion. Update the existing fault-protected load test state description. The post-unlock pointer no longer carries NON_OWN_REF, but remains readable because the load is rewritten to use BPF_PROBE_MEM. Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- drivers/hid/hid-lg2ff.c | 95 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 95 insertions(+) create mode 100644 drivers/hid/hid-lg2ff.c (limited to 'drivers/hid/hid-lg2ff.c') diff --git a/drivers/hid/hid-lg2ff.c b/drivers/hid/hid-lg2ff.c new file mode 100644 index 000000000..c3e85b079 --- /dev/null +++ b/drivers/hid/hid-lg2ff.c @@ -0,0 +1,95 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Force feedback support for Logitech RumblePad and Rumblepad 2 + * + * Copyright (c) 2008 Anssi Hannula + */ + +/* + */ + + +#include +#include +#include + +#include "hid-lg.h" + +struct lg2ff_device { + struct hid_report *report; +}; + +static int play_effect(struct input_dev *dev, void *data, + struct ff_effect *effect) +{ + struct hid_device *hid = input_get_drvdata(dev); + struct lg2ff_device *lg2ff = data; + int weak, strong; + + strong = effect->u.rumble.strong_magnitude; + weak = effect->u.rumble.weak_magnitude; + + if (weak || strong) { + weak = weak * 0xff / 0xffff; + strong = strong * 0xff / 0xffff; + + lg2ff->report->field[0]->value[0] = 0x51; + lg2ff->report->field[0]->value[2] = weak; + lg2ff->report->field[0]->value[4] = strong; + } else { + lg2ff->report->field[0]->value[0] = 0xf3; + lg2ff->report->field[0]->value[2] = 0x00; + lg2ff->report->field[0]->value[4] = 0x00; + } + + hid_hw_request(hid, lg2ff->report, HID_REQ_SET_REPORT); + return 0; +} + +int lg2ff_init(struct hid_device *hid) +{ + struct lg2ff_device *lg2ff; + struct hid_report *report; + struct hid_input *hidinput; + struct input_dev *dev; + int error; + + if (list_empty(&hid->inputs)) { + hid_err(hid, "no inputs found\n"); + return -ENODEV; + } + hidinput = list_entry(hid->inputs.next, struct hid_input, list); + dev = hidinput->input; + + /* Check that the report looks ok */ + report = hid_validate_values(hid, HID_OUTPUT_REPORT, 0, 0, 7); + if (!report) + return -ENODEV; + + lg2ff = kmalloc_obj(struct lg2ff_device); + if (!lg2ff) + return -ENOMEM; + + set_bit(FF_RUMBLE, dev->ffbit); + + error = input_ff_create_memless(dev, lg2ff, play_effect); + if (error) { + kfree(lg2ff); + return error; + } + + lg2ff->report = report; + report->field[0]->value[0] = 0xf3; + report->field[0]->value[1] = 0x00; + report->field[0]->value[2] = 0x00; + report->field[0]->value[3] = 0x00; + report->field[0]->value[4] = 0x00; + report->field[0]->value[5] = 0x00; + report->field[0]->value[6] = 0x00; + + hid_hw_request(hid, report, HID_REQ_SET_REPORT); + + hid_info(hid, "Force feedback for Logitech variant 2 rumble devices by Anssi Hannula \n"); + + return 0; +} -- cgit v1.3.1