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/btrfs/Kconfig | 118 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 118 insertions(+) create mode 100644 fs/btrfs/Kconfig (limited to 'fs/btrfs/Kconfig') diff --git a/fs/btrfs/Kconfig b/fs/btrfs/Kconfig new file mode 100644 index 000000000..4b10d78ed --- /dev/null +++ b/fs/btrfs/Kconfig @@ -0,0 +1,118 @@ +# SPDX-License-Identifier: GPL-2.0 + +config BTRFS_FS + tristate "Btrfs filesystem support" + select BLK_CGROUP_PUNT_BIO + select CRC32 + select CRYPTO_LIB_BLAKE2B + select CRYPTO_LIB_SHA256 + select ZLIB_INFLATE + select ZLIB_DEFLATE + select LZO_COMPRESS + select LZO_DECOMPRESS + select ZSTD_COMPRESS + select ZSTD_DECOMPRESS + select FS_IOMAP + select RAID6_PQ + select XOR_BLOCKS + select XXHASH + depends on PAGE_SIZE_LESS_THAN_256KB + + help + Btrfs is a general purpose copy-on-write filesystem with extents, + writable snapshotting, support for multiple devices and many more + features focused on fault tolerance, repair and easy administration. + + The filesystem disk format is no longer unstable, and it's not + expected to change unless there are strong reasons to do so. If there + is a format change, file systems with a unchanged format will + continue to be mountable and usable by newer kernels. + + For more information, please see the web pages at + https://btrfs.readthedocs.io + + To compile this file system support as a module, choose M here. The + module will be called btrfs. + + If unsure, say N. + +config BTRFS_FS_POSIX_ACL + bool "Btrfs POSIX Access Control Lists" + depends on BTRFS_FS + select FS_POSIX_ACL + help + POSIX Access Control Lists (ACLs) support permissions for users and + groups beyond the owner/group/world scheme. + + If you don't know what Access Control Lists are, say N + +config BTRFS_FS_RUN_SANITY_TESTS + bool "Btrfs will run sanity tests upon loading" + depends on BTRFS_FS + help + This will run sanity tests for core functionality like free space, + extent maps, extent io, extent buffers, inodes, qgroups and others, + at module load time. These are mostly regression tests and are only + interesting to developers. + + If unsure, say N. + +config BTRFS_DEBUG + bool "Btrfs debugging support" + depends on BTRFS_FS + select REF_TRACKER if STACKTRACE_SUPPORT + help + Enable run-time debugging support for the btrfs filesystem. + + Additional potentially expensive checks, debugging functionality or + sysfs exported information is enabled, like leak checks of internal + objects, optional forced space fragmentation and /sys/fs/btrfs/debug . + This has negative impact on performance. + + If unsure, say N. + +config BTRFS_ASSERT + bool "Btrfs assert support" + depends on BTRFS_FS + help + Enable run-time assertion checking. Additional safety checks are + done, simple enough not to affect performance but verify invariants + and assumptions of code to run properly. This may result in panics, + and is meant for developers but can be enabled in general. + + If unsure, say N. + +config BTRFS_EXPERIMENTAL + bool "Btrfs experimental features" + depends on BTRFS_FS + default n + help + Enable experimental features. These features may not be stable enough + for end users. This is meant for btrfs developers or users who wish + to test the functionality and report problems. + + Current list: + + - RAID mirror read policy - additional read policies for balancing + reading from redundant block group + profiles (currently: pid, round-robin, + fixed devid) + + - send stream protocol v3 - fs-verity support + + - raid-stripe-tree - additional mapping of extents to devices to + support RAID1* profiles on zoned devices, + RAID56 not yet supported + + - extent tree v2 - complex rework of extent tracking + + - block size > page size support - needs transparent huge page and + non-HIGHMEM system + + - huge folios for data - folios can be as large as 2MiB now + + - asynchronous checksum generation for data writes + + - remap-tree - logical address remapping tree + + If unsure, say N. -- cgit v1.3.1