linux/arch/s390/hypfs
Peter Oberparleiter 3868f91044 s390/hypfs: Enable limited access during lockdown
When kernel lockdown is active, debugfs_locked_down() blocks access to
hypfs files that register ioctl callbacks, even if the ioctl interface
is not required for a function. This unnecessarily breaks userspace
tools that only rely on read operations.

Resolve this by registering a minimal set of file operations during
lockdown, avoiding ioctl registration and preserving access for affected
tooling.

Note that this change restores hypfs functionality when lockdown is
active from early boot (e.g. via lockdown=integrity kernel parameter),
but does not apply to scenarios where lockdown is enabled dynamically
while Linux is running.

Tested-by: Mete Durlu <meted@linux.ibm.com>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Fixes: 5496197f9b ("debugfs: Restrict debugfs when the kernel is locked down")
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
History 2025-08-21 17:46:14 +02:00
..
hypfs.h s390: Handle KCOV __init vs inline mismatches 2025-07-21 21:44:01 -07:00
hypfs_dbfs.c s390/hypfs: Enable limited access during lockdown 2025-08-21 17:46:14 +02:00
hypfs_diag.c s390/hypfs_diag: Remove unused dentry variable 2024-08-29 22:56:33 +02:00
hypfs_diag.h s390: Handle KCOV __init vs inline mismatches 2025-07-21 21:44:01 -07:00
hypfs_diag0c.c s390: Convert MACHINE_IS_[LPAR|VM|KVM], etc, machine_is_[lpar|vm|kvm]() 2025-03-04 17:18:07 +01:00
hypfs_diag_fs.c fixes for bugs caught as part of tree-in-dcache work 2025-04-03 21:12:48 -07:00
hypfs_sprp.c s390/hypfs_sprp: remove unneeded DMA zone allocation 2024-02-09 13:58:14 +01:00
hypfs_vm.c s390: Convert MACHINE_IS_[LPAR|VM|KVM], etc, machine_is_[lpar|vm|kvm]() 2025-03-04 17:18:07 +01:00
hypfs_vm.h s390/hypfs: factor out filesystem code 2023-07-24 12:12:22 +02:00
hypfs_vm_fs.c s390/hypfs: factor out filesystem code 2023-07-24 12:12:22 +02:00
inode.c VFS: rename lookup_one_len family to lookup_noperm and remove permission check 2025-04-08 11:24:36 +02:00
Makefile s390/hypfs: factor out filesystem code 2023-07-24 12:12:22 +02:00