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/gpu/host1x/channel.h | 45 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) create mode 100644 drivers/gpu/host1x/channel.h (limited to 'drivers/gpu/host1x/channel.h') diff --git a/drivers/gpu/host1x/channel.h b/drivers/gpu/host1x/channel.h new file mode 100644 index 000000000..d7aede204 --- /dev/null +++ b/drivers/gpu/host1x/channel.h @@ -0,0 +1,45 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Tegra host1x Channel + * + * Copyright (c) 2010-2013, NVIDIA Corporation. + */ + +#ifndef __HOST1X_CHANNEL_H +#define __HOST1X_CHANNEL_H + +#include +#include +#include + +#include "cdma.h" + +struct host1x; +struct host1x_channel; + +struct host1x_channel_list { + struct host1x_channel *channels; + + struct mutex lock; + unsigned long *allocated_channels; +}; + +struct host1x_channel { + struct kref refcount; + unsigned int id; + struct mutex submitlock; + void __iomem *regs; + struct host1x_client *client; + struct device *dev; + struct host1x_cdma cdma; +}; + +/* channel list operations */ +int host1x_channel_list_init(struct host1x_channel_list *chlist, + unsigned int num_channels); +void host1x_channel_list_free(struct host1x_channel_list *chlist); +struct host1x_channel *host1x_channel_get_index(struct host1x *host, + unsigned int index); +void host1x_channel_stop_all(struct host1x *host); + +#endif -- cgit v1.3.1