linux/arch/s390
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>
2025-08-21 17:46:14 +02:00
..
appldata s390: Explicitly include <linux/export.h> 2025-06-17 18:18:02 +02:00
boot s390/mm: Do not map lowcore with identity mapping 2025-08-20 16:37:28 +02:00
configs s390/configs: Set HZ=1000 2025-08-20 16:37:27 +02:00
crypto This update includes the following changes: 2025-07-31 09:45:28 -07:00
hypfs s390/hypfs: Enable limited access during lockdown 2025-08-21 17:46:14 +02:00
include more s390 updates for 6.17 merge window 2025-08-08 06:56:55 +03:00
kernel more s390 updates for 6.17 merge window 2025-08-08 06:56:55 +03:00
kvm ARM: 2025-07-30 17:14:01 -07:00
lib s390 updates for 6.17 merge window 2025-07-29 20:17:08 -07:00
mm more s390 updates for 6.17 merge window 2025-08-08 06:56:55 +03:00
net bpf-next-6.17 2025-07-30 09:58:50 -07:00
pci s390 updates for 6.17 merge window 2025-07-29 20:17:08 -07:00
purgatory lib/crypto: sha256: Make library API use strongly-typed contexts 2025-07-04 10:18:53 -07:00
tools s390: Allow to compile with z17 optimizations 2025-04-09 12:12:41 +02:00
Kbuild
Kconfig more s390 updates for 6.17 merge window 2025-08-08 06:56:55 +03:00
Kconfig.debug s390/mm: Add configurable STRICT_MM_TYPECHECKS 2025-03-11 15:27:34 +01:00
Makefile s390: Allow to compile with z17 optimizations 2025-04-09 12:12:41 +02:00
Makefile.postlink kbuild: Create intermediate vmlinux build with relocations preserved 2025-03-17 00:29:50 +09:00