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 --- sound/firewire/iso-resources.h | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) create mode 100644 sound/firewire/iso-resources.h (limited to 'sound/firewire/iso-resources.h') diff --git a/sound/firewire/iso-resources.h b/sound/firewire/iso-resources.h new file mode 100644 index 000000000..34f85e9e8 --- /dev/null +++ b/sound/firewire/iso-resources.h @@ -0,0 +1,39 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef SOUND_FIREWIRE_ISO_RESOURCES_H_INCLUDED +#define SOUND_FIREWIRE_ISO_RESOURCES_H_INCLUDED + +#include +#include + +struct fw_unit; + +/** + * struct fw_iso_resources - manages channel/bandwidth allocation + * @channels_mask: if the device does not support all channel numbers, set this + * bit mask to something else than the default (all ones) + * + * This structure manages (de)allocation of isochronous resources (channel and + * bandwidth) for one isochronous stream. + */ +struct fw_iso_resources { + u64 channels_mask; + /* private: */ + struct fw_unit *unit; + struct mutex mutex; + unsigned int channel; + unsigned int bandwidth; /* in bandwidth units, without overhead */ + unsigned int bandwidth_overhead; + int generation; /* in which allocation is valid */ + bool allocated; +}; + +int fw_iso_resources_init(struct fw_iso_resources *r, + struct fw_unit *unit); +void fw_iso_resources_destroy(struct fw_iso_resources *r); + +int fw_iso_resources_allocate(struct fw_iso_resources *r, + unsigned int max_payload_bytes, int speed); +int fw_iso_resources_update(struct fw_iso_resources *r); +void fw_iso_resources_free(struct fw_iso_resources *r); + +#endif -- cgit v1.3.1