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/cmp.h | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100644 sound/firewire/cmp.h (limited to 'sound/firewire/cmp.h') diff --git a/sound/firewire/cmp.h b/sound/firewire/cmp.h new file mode 100644 index 000000000..66fc08b74 --- /dev/null +++ b/sound/firewire/cmp.h @@ -0,0 +1,52 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef SOUND_FIREWIRE_CMP_H_INCLUDED +#define SOUND_FIREWIRE_CMP_H_INCLUDED + +#include +#include +#include "iso-resources.h" + +struct fw_unit; + +enum cmp_direction { + CMP_INPUT = 0, + CMP_OUTPUT, +}; + +/** + * struct cmp_connection - manages an isochronous connection to a device + * @speed: the connection's actual speed + * + * This structure manages (using CMP) an isochronous stream between the local + * computer and a device's input plug (iPCR) and output plug (oPCR). + * + * There is no corresponding oPCR created on the local computer, so it is not + * possible to overlay connections on top of this one. + */ +struct cmp_connection { + int speed; + /* private: */ + bool connected; + struct mutex mutex; + struct fw_iso_resources resources; + __be32 last_pcr_value; + unsigned int pcr_index; + unsigned int max_speed; + enum cmp_direction direction; +}; + +int cmp_connection_init(struct cmp_connection *connection, + struct fw_unit *unit, + enum cmp_direction direction, + unsigned int pcr_index); +int cmp_connection_check_used(struct cmp_connection *connection, bool *used); +void cmp_connection_destroy(struct cmp_connection *connection); + +int cmp_connection_reserve(struct cmp_connection *connection, + unsigned int max_payload); +void cmp_connection_release(struct cmp_connection *connection); + +int cmp_connection_establish(struct cmp_connection *connection); +void cmp_connection_break(struct cmp_connection *connection); + +#endif -- cgit v1.3.1