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/fuse/Kconfig | 78 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 78 insertions(+) create mode 100644 fs/fuse/Kconfig (limited to 'fs/fuse/Kconfig') diff --git a/fs/fuse/Kconfig b/fs/fuse/Kconfig new file mode 100644 index 000000000..3a4ae632c --- /dev/null +++ b/fs/fuse/Kconfig @@ -0,0 +1,78 @@ +# SPDX-License-Identifier: GPL-2.0-only +config FUSE_FS + tristate "FUSE (Filesystem in Userspace) support" + select FS_POSIX_ACL + select FS_IOMAP + help + With FUSE it is possible to implement a fully functional filesystem + in a userspace program. + + There's also a companion library: libfuse2. This library is available + from the FUSE homepage: + + although chances are your distribution already has that library + installed if you've installed the "fuse" package itself. + + See for more information. + See for needed library/utility version. + + If you want to develop a userspace FS, or if you want to use + a filesystem based on FUSE, answer Y or M. + +config CUSE + tristate "Character device in Userspace support" + depends on FUSE_FS + help + This FUSE extension allows character devices to be + implemented in userspace. + + If you want to develop or use a userspace character device + based on CUSE, answer Y or M. + +config VIRTIO_FS + tristate "Virtio Filesystem" + depends on FUSE_FS + select VIRTIO + help + The Virtio Filesystem allows guests to mount file systems from the + host. + + If you want to share files between guests or with the host, answer Y + or M. + +config FUSE_DAX + bool "Virtio Filesystem Direct Host Memory Access support" + default y + select INTERVAL_TREE + depends on VIRTIO_FS + depends on FS_DAX + depends on DAX + help + This allows bypassing guest page cache and allows mapping host page + cache directly in guest address space. + + If you want to allow mounting a Virtio Filesystem with the "dax" + option, answer Y. + +config FUSE_PASSTHROUGH + bool "FUSE passthrough operations support" + default y + depends on FUSE_FS + select FS_STACK + help + This allows bypassing FUSE server by mapping specific FUSE operations + to be performed directly on a backing file. + + If you want to allow passthrough operations, answer Y. + +config FUSE_IO_URING + bool "FUSE communication over io-uring" + default y + depends on FUSE_FS + depends on IO_URING + help + This allows sending FUSE requests over the io-uring interface and + also adds request core affinity. + + If you want to allow fuse server/client communication through io-uring, + answer Y -- cgit v1.3.1