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/md/raid0.h | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) create mode 100644 drivers/md/raid0.h (limited to 'drivers/md/raid0.h') diff --git a/drivers/md/raid0.h b/drivers/md/raid0.h new file mode 100644 index 000000000..8cc761ca7 --- /dev/null +++ b/drivers/md/raid0.h @@ -0,0 +1,33 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _RAID0_H +#define _RAID0_H + +struct strip_zone { + sector_t zone_end; /* Start of the next zone (in sectors) */ + sector_t dev_start; /* Zone offset in real dev (in sectors) */ + int nb_dev; /* # of devices attached to the zone */ + int disk_shift; /* start disk for the original layout */ +}; + +/* Linux 3.14 (20d0189b101) made an unintended change to + * the RAID0 layout for multi-zone arrays (where devices aren't all + * the same size. + * RAID0_ORIG_LAYOUT restores the original layout + * RAID0_ALT_MULTIZONE_LAYOUT uses the altered layout + * The layouts are identical when there is only one zone (all + * devices the same size). + */ + +enum r0layout { + RAID0_ORIG_LAYOUT = 1, + RAID0_ALT_MULTIZONE_LAYOUT = 2, +}; +struct r0conf { + struct strip_zone *strip_zone; + struct md_rdev **devlist; /* lists of rdevs, pointed to + * by strip_zone->dev */ + int nr_strip_zones; + enum r0layout layout; +}; + +#endif -- cgit v1.3.1