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-picolcd_cir.c | 139 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 139 insertions(+) create mode 100644 drivers/hid/hid-picolcd_cir.c (limited to 'drivers/hid/hid-picolcd_cir.c') diff --git a/drivers/hid/hid-picolcd_cir.c b/drivers/hid/hid-picolcd_cir.c new file mode 100644 index 000000000..6d4c636e1 --- /dev/null +++ b/drivers/hid/hid-picolcd_cir.c @@ -0,0 +1,139 @@ +// SPDX-License-Identifier: GPL-2.0-only +/*************************************************************************** + * Copyright (C) 2010-2012 by Bruno Prémont * + * * + * Based on Logitech G13 driver (v0.4) * + * Copyright (C) 2009 by Rick L. Vinyard, Jr. * + * * + ***************************************************************************/ + +#include +#include +#include +#include "hid-ids.h" + +#include +#include +#include +#include + +#include + +#include +#include + +#include +#include +#include +#include + +#include "hid-picolcd.h" + + +int picolcd_raw_cir(struct picolcd_data *data, + struct hid_report *report, u8 *raw_data, int size) +{ + unsigned long flags; + int i, w, sz; + struct ir_raw_event rawir = {}; + + /* ignore if rc_dev is NULL or status is shunned */ + spin_lock_irqsave(&data->lock, flags); + if (!data->rc_dev || (data->status & PICOLCD_CIR_SHUN)) { + spin_unlock_irqrestore(&data->lock, flags); + return 1; + } + spin_unlock_irqrestore(&data->lock, flags); + + /* PicoLCD USB packets contain 16-bit intervals in network order, + * with value negated for pulse. Intervals are in microseconds. + * + * Note: some userspace LIRC code for PicoLCD says negated values + * for space - is it a matter of IR chip? (pulse for my TSOP2236) + * + * In addition, the first interval seems to be around 15000 + base + * interval for non-first report of IR data - thus the quirk below + * to get RC_CODE to understand Sony and JVC remotes I have at hand + */ + sz = size > 0 ? min((int)raw_data[0], size-1) : 0; + for (i = 0; i+1 < sz; i += 2) { + w = (raw_data[i] << 8) | (raw_data[i+1]); + rawir.pulse = !!(w & 0x8000); + rawir.duration = rawir.pulse ? (65536 - w) : w; + /* Quirk!! - see above */ + if (i == 0 && rawir.duration > 15000) + rawir.duration -= 15000; + ir_raw_event_store(data->rc_dev, &rawir); + } + ir_raw_event_handle(data->rc_dev); + + return 1; +} + +static int picolcd_cir_open(struct rc_dev *dev) +{ + struct picolcd_data *data = dev->priv; + unsigned long flags; + + spin_lock_irqsave(&data->lock, flags); + data->status &= ~PICOLCD_CIR_SHUN; + spin_unlock_irqrestore(&data->lock, flags); + return 0; +} + +static void picolcd_cir_close(struct rc_dev *dev) +{ + struct picolcd_data *data = dev->priv; + unsigned long flags; + + spin_lock_irqsave(&data->lock, flags); + data->status |= PICOLCD_CIR_SHUN; + spin_unlock_irqrestore(&data->lock, flags); +} + +/* initialize CIR input device */ +int picolcd_init_cir(struct picolcd_data *data, struct hid_report *report) +{ + struct rc_dev *rdev; + int ret = 0; + + rdev = rc_allocate_device(RC_DRIVER_IR_RAW); + if (!rdev) + return -ENOMEM; + + rdev->priv = data; + rdev->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER; + rdev->open = picolcd_cir_open; + rdev->close = picolcd_cir_close; + rdev->device_name = data->hdev->name; + rdev->input_phys = data->hdev->phys; + rdev->input_id.bustype = data->hdev->bus; + rdev->input_id.vendor = data->hdev->vendor; + rdev->input_id.product = data->hdev->product; + rdev->input_id.version = data->hdev->version; + rdev->dev.parent = &data->hdev->dev; + rdev->driver_name = PICOLCD_NAME; + rdev->map_name = RC_MAP_RC6_MCE; + rdev->timeout = MS_TO_US(100); + rdev->rx_resolution = 1; + + ret = rc_register_device(rdev); + if (ret) + goto err; + data->rc_dev = rdev; + return 0; + +err: + rc_free_device(rdev); + return ret; +} + +void picolcd_exit_cir(struct picolcd_data *data) +{ + struct rc_dev *rdev = data->rc_dev; + + data->rc_dev = NULL; + rc_unregister_device(rdev); + rc_free_device(rdev); +} + -- cgit v1.3.1