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/gfs2/log.h | 63 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 fs/gfs2/log.h (limited to 'fs/gfs2/log.h') diff --git a/fs/gfs2/log.h b/fs/gfs2/log.h new file mode 100644 index 000000000..10beda624 --- /dev/null +++ b/fs/gfs2/log.h @@ -0,0 +1,63 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. + * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved. + */ + +#ifndef __LOG_DOT_H__ +#define __LOG_DOT_H__ + +#include +#include +#include +#include "incore.h" +#include "inode.h" + +/* + * The minimum amount of log space required for a log flush is one block for + * revokes and one block for the log header. Log flushes other than + * GFS2_LOG_HEAD_FLUSH_NORMAL may write one or two more log headers. + */ +#define GFS2_LOG_FLUSH_MIN_BLOCKS 4 + +static inline void gfs2_ordered_add_inode(struct gfs2_inode *ip) +{ + struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); + + if (gfs2_is_jdata(ip) || !gfs2_is_ordered(sdp)) + return; + + if (list_empty(&ip->i_ordered)) { + spin_lock(&sdp->sd_ordered_lock); + if (list_empty(&ip->i_ordered)) + list_add(&ip->i_ordered, &sdp->sd_log_ordered); + spin_unlock(&sdp->sd_ordered_lock); + } +} + +void gfs2_ordered_del_inode(struct gfs2_inode *ip); +unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct); +bool gfs2_log_is_empty(struct gfs2_sbd *sdp); +void gfs2_log_release_revokes(struct gfs2_sbd *sdp, unsigned int revokes); +void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks); +bool gfs2_log_try_reserve(struct gfs2_sbd *sdp, struct gfs2_trans *tr, + unsigned int *extra_revokes); +void gfs2_log_reserve(struct gfs2_sbd *sdp, struct gfs2_trans *tr, + unsigned int *extra_revokes); +void gfs2_write_log_header(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd, + u64 seq, u32 tail, u32 lblock, u32 flags, + blk_opf_t op_flags); +void gfs2_remove_from_journal(struct buffer_head *bh, int meta); +void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl, + u32 type); +void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *trans); +void gfs2_ail1_flush(struct gfs2_sbd *sdp, struct writeback_control *wbc); +void log_flush_wait(struct gfs2_sbd *sdp); + +int gfs2_logd(void *data); +void gfs2_add_revoke(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd); +void gfs2_glock_remove_revoke(struct gfs2_glock *gl); +void gfs2_flush_revokes(struct gfs2_sbd *sdp); +void gfs2_ail_drain(struct gfs2_sbd *sdp); + +#endif /* __LOG_DOT_H__ */ -- cgit v1.3.1