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 --- fs/smb/client/smbdirect.h | 67 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 67 insertions(+) create mode 100644 fs/smb/client/smbdirect.h (limited to 'fs/smb/client/smbdirect.h') diff --git a/fs/smb/client/smbdirect.h b/fs/smb/client/smbdirect.h new file mode 100644 index 000000000..be205ec02 --- /dev/null +++ b/fs/smb/client/smbdirect.h @@ -0,0 +1,67 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (C) 2017, Microsoft Corporation. + * + * Author(s): Long Li + */ +#ifndef _SMBDIRECT_H +#define _SMBDIRECT_H + +#ifdef CONFIG_CIFS_SMB_DIRECT +#define cifs_rdma_enabled(server) ((server)->rdma) + +#include "cifsglob.h" + +#include + +extern int rdma_readwrite_threshold; +extern int smbd_max_frmr_depth; +extern int smbd_keep_alive_interval; +extern int smbd_max_receive_size; +extern int smbd_max_fragmented_recv_size; +extern int smbd_max_send_size; +extern int smbd_send_credit_target; +extern int smbd_receive_credit_max; + +struct smbd_connection { + struct smbdirect_socket *socket; +}; + +/* Create a SMBDirect session */ +struct smbd_connection *smbd_get_connection( + struct TCP_Server_Info *server, struct sockaddr *dstaddr); + +const struct smbdirect_socket_parameters *smbd_get_parameters(struct smbd_connection *conn); + +/* Reconnect SMBDirect session */ +int smbd_reconnect(struct TCP_Server_Info *server); +/* Destroy SMBDirect session */ +void smbd_destroy(struct TCP_Server_Info *server); + +/* Interface for carrying upper layer I/O through send/recv */ +int smbd_recv(struct smbd_connection *info, struct msghdr *msg); +int smbd_send(struct TCP_Server_Info *server, + int num_rqst, struct smb_rqst *rqst); + +/* Interfaces to register and deregister MR for RDMA read/write */ +struct smbdirect_mr_io *smbd_register_mr( + struct smbd_connection *info, struct iov_iter *iter, + bool writing, bool need_invalidate); +void smbd_mr_fill_buffer_descriptor(struct smbdirect_mr_io *mr, + struct smbdirect_buffer_descriptor_v1 *v1); +void smbd_deregister_mr(struct smbdirect_mr_io *mr); + +void smbd_debug_proc_show(struct TCP_Server_Info *server, struct seq_file *m); + +#else +#define cifs_rdma_enabled(server) 0 +struct smbd_connection {}; +static inline void *smbd_get_connection( + struct TCP_Server_Info *server, struct sockaddr *dstaddr) {return NULL;} +static inline int smbd_reconnect(struct TCP_Server_Info *server) {return -1; } +static inline void smbd_destroy(struct TCP_Server_Info *server) {} +static inline int smbd_recv(struct smbd_connection *info, struct msghdr *msg) {return -1; } +static inline int smbd_send(struct TCP_Server_Info *server, int num_rqst, struct smb_rqst *rqst) {return -1; } +#endif + +#endif -- cgit v1.3.1