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/ceph/cache.h | 117 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 117 insertions(+) create mode 100644 fs/ceph/cache.h (limited to 'fs/ceph/cache.h') diff --git a/fs/ceph/cache.h b/fs/ceph/cache.h new file mode 100644 index 000000000..20efac020 --- /dev/null +++ b/fs/ceph/cache.h @@ -0,0 +1,117 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Ceph cache definitions. + * + * Copyright (C) 2013 by Adfin Solutions, Inc. All Rights Reserved. + * Written by Milosz Tanski (milosz@adfin.com) + */ + +#ifndef _CEPH_CACHE_H +#define _CEPH_CACHE_H + +#include + +#ifdef CONFIG_CEPH_FSCACHE +#include + +int ceph_fscache_register_fs(struct ceph_fs_client* fsc, struct fs_context *fc); +void ceph_fscache_unregister_fs(struct ceph_fs_client* fsc); + +void ceph_fscache_register_inode_cookie(struct inode *inode); +void ceph_fscache_unregister_inode_cookie(struct ceph_inode_info* ci); + +void ceph_fscache_use_cookie(struct inode *inode, bool will_modify); +void ceph_fscache_unuse_cookie(struct inode *inode, bool update); + +void ceph_fscache_update(struct inode *inode); +void ceph_fscache_invalidate(struct inode *inode, bool dio_write); + +static inline struct fscache_cookie *ceph_fscache_cookie(struct ceph_inode_info *ci) +{ + return netfs_i_cookie(&ci->netfs); +} + +static inline void ceph_fscache_resize(struct inode *inode, loff_t to) +{ + struct ceph_inode_info *ci = ceph_inode(inode); + struct fscache_cookie *cookie = ceph_fscache_cookie(ci); + + if (cookie) { + ceph_fscache_use_cookie(inode, true); + fscache_resize_cookie(cookie, to); + ceph_fscache_unuse_cookie(inode, true); + } +} + +static inline int ceph_fscache_unpin_writeback(struct inode *inode, + struct writeback_control *wbc) +{ + return netfs_unpin_writeback(inode, wbc); +} + +#define ceph_fscache_dirty_folio netfs_dirty_folio + +static inline bool ceph_is_cache_enabled(struct inode *inode) +{ + return fscache_cookie_enabled(ceph_fscache_cookie(ceph_inode(inode))); +} + +#else /* CONFIG_CEPH_FSCACHE */ +static inline int ceph_fscache_register_fs(struct ceph_fs_client* fsc, + struct fs_context *fc) +{ + return 0; +} + +static inline void ceph_fscache_unregister_fs(struct ceph_fs_client* fsc) +{ +} + +static inline void ceph_fscache_register_inode_cookie(struct inode *inode) +{ +} + +static inline void ceph_fscache_unregister_inode_cookie(struct ceph_inode_info* ci) +{ +} + +static inline void ceph_fscache_use_cookie(struct inode *inode, bool will_modify) +{ +} + +static inline void ceph_fscache_unuse_cookie(struct inode *inode, bool update) +{ +} + +static inline void ceph_fscache_update(struct inode *inode) +{ +} + +static inline void ceph_fscache_invalidate(struct inode *inode, bool dio_write) +{ +} + +static inline struct fscache_cookie *ceph_fscache_cookie(struct ceph_inode_info *ci) +{ + return NULL; +} + +static inline void ceph_fscache_resize(struct inode *inode, loff_t to) +{ +} + +static inline int ceph_fscache_unpin_writeback(struct inode *inode, + struct writeback_control *wbc) +{ + return 0; +} + +#define ceph_fscache_dirty_folio filemap_dirty_folio + +static inline bool ceph_is_cache_enabled(struct inode *inode) +{ + return false; +} +#endif /* CONFIG_CEPH_FSCACHE */ + +#endif -- cgit v1.3.1