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/qcom/trace-smp2p.h | 98 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 98 insertions(+) create mode 100644 drivers/soc/qcom/trace-smp2p.h (limited to 'drivers/soc/qcom/trace-smp2p.h') diff --git a/drivers/soc/qcom/trace-smp2p.h b/drivers/soc/qcom/trace-smp2p.h new file mode 100644 index 000000000..9a6392043 --- /dev/null +++ b/drivers/soc/qcom/trace-smp2p.h @@ -0,0 +1,98 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved. + */ + +#undef TRACE_SYSTEM +#define TRACE_SYSTEM qcom_smp2p + +#if !defined(__QCOM_SMP2P_TRACE_H__) || defined(TRACE_HEADER_MULTI_READ) +#define __QCOM_SMP2P_TRACE_H__ + +#include +#include + +TRACE_EVENT(smp2p_ssr_ack, + TP_PROTO(const struct device *dev), + TP_ARGS(dev), + TP_STRUCT__entry( + __string(dev_name, dev_name(dev)) + ), + TP_fast_assign( + __assign_str(dev_name); + ), + TP_printk("%s: SSR detected", __get_str(dev_name)) +); + +TRACE_EVENT(smp2p_negotiate, + TP_PROTO(const struct device *dev, unsigned int features), + TP_ARGS(dev, features), + TP_STRUCT__entry( + __string(dev_name, dev_name(dev)) + __field(u32, out_features) + ), + TP_fast_assign( + __assign_str(dev_name); + __entry->out_features = features; + ), + TP_printk("%s: state=open out_features=%s", __get_str(dev_name), + __print_flags(__entry->out_features, "|", + {SMP2P_FEATURE_SSR_ACK, "SMP2P_FEATURE_SSR_ACK"}) + ) +); + +TRACE_EVENT(smp2p_notify_in, + TP_PROTO(struct smp2p_entry *smp2p_entry, unsigned long status, u32 val), + TP_ARGS(smp2p_entry, status, val), + TP_STRUCT__entry( + __string(dev_name, dev_name(smp2p_entry->smp2p->dev)) + __string(client_name, smp2p_entry->name) + __field(unsigned long, status) + __field(u32, val) + ), + TP_fast_assign( + __assign_str(dev_name); + __assign_str(client_name); + __entry->status = status; + __entry->val = val; + ), + TP_printk("%s: %s: status:0x%0lx val:0x%0x", + __get_str(dev_name), + __get_str(client_name), + __entry->status, + __entry->val + ) +); + +TRACE_EVENT(smp2p_update_bits, + TP_PROTO(struct smp2p_entry *smp2p_entry, u32 orig, u32 val), + TP_ARGS(smp2p_entry, orig, val), + TP_STRUCT__entry( + __string(dev_name, dev_name(smp2p_entry->smp2p->dev)) + __string(client_name, smp2p_entry->name) + __field(u32, orig) + __field(u32, val) + ), + TP_fast_assign( + __assign_str(dev_name); + __assign_str(client_name); + __entry->orig = orig; + __entry->val = val; + ), + TP_printk("%s: %s: orig:0x%0x new:0x%0x", + __get_str(dev_name), + __get_str(client_name), + __entry->orig, + __entry->val + ) +); + +#endif /* __QCOM_SMP2P_TRACE_H__ */ + +#undef TRACE_INCLUDE_PATH +#define TRACE_INCLUDE_PATH . + +#undef TRACE_INCLUDE_FILE +#define TRACE_INCLUDE_FILE trace-smp2p + +#include -- cgit v1.3.1