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/soc/apple/mailbox.h | 48 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 drivers/soc/apple/mailbox.h (limited to 'drivers/soc/apple/mailbox.h') diff --git a/drivers/soc/apple/mailbox.h b/drivers/soc/apple/mailbox.h new file mode 100644 index 000000000..f73a8913d --- /dev/null +++ b/drivers/soc/apple/mailbox.h @@ -0,0 +1,48 @@ +/* SPDX-License-Identifier: GPL-2.0-only OR MIT */ +/* + * Apple mailbox message format + * + * Copyright The Asahi Linux Contributors + */ + +#ifndef _APPLE_MAILBOX_H_ +#define _APPLE_MAILBOX_H_ + +#include +#include + +/* encodes a single 96bit message sent over the single channel */ +struct apple_mbox_msg { + u64 msg0; + u32 msg1; +}; + +struct apple_mbox { + struct device *dev; + void __iomem *regs; + const struct apple_mbox_hw *hw; + bool active; + + int irq_recv_not_empty; + int irq_send_empty; + + spinlock_t rx_lock; + spinlock_t tx_lock; + + struct completion tx_empty; + + /** Receive callback for incoming messages */ + void (*rx)(struct apple_mbox *mbox, struct apple_mbox_msg msg, void *cookie); + void *cookie; +}; + +struct apple_mbox *apple_mbox_get(struct device *dev, int index); +struct apple_mbox *apple_mbox_get_byname(struct device *dev, const char *name); + +int apple_mbox_start(struct apple_mbox *mbox); +void apple_mbox_stop(struct apple_mbox *mbox); +int apple_mbox_poll(struct apple_mbox *mbox); +int apple_mbox_send(struct apple_mbox *mbox, struct apple_mbox_msg msg, + bool atomic); + +#endif -- cgit v1.3.1