wireguard-linux/drivers/s390/cio, branch stable

s390/cio: Fix NULL pointer dereference in ccw_device_get_util_str()

2026-09-23T14:43:32Z

The channel path registry entry associated with a CHPID may be removed while the subchannel's PMCW still references that CHPID. In this case, chpid_to_chp() can return NULL, leading to a NULL pointer dereference. Add the missing NULL check before dereferencing the returned pointer. Fixes: 199652309a4d ("s390/cio: add helper to query utility strings per given ccw device") Cc: stable@vger.kernel.org Signed-off-by: Vineeth Vijayan Reviewed-by: Peter Oberparleiter Signed-off-by: Heiko Carstens

s390/cmf: Fix virtual vs physical address confusion

2026-09-22T10:21:04Z

The measurement block address is an absolute address. Define the associated schib_config and schib fields as dma64_t to enable automatic detection of incorrect assignments. Also add the missing virt_to_dma64() translation. Without this fix, a wrong address will be used by firmware when storing extended format channel measurement data on kernels built with CONFIG_RANDOMIZE_IDENTITY_BASE=y. Fixes: 14edd0d73bfe ("s390/cmf: fix virtual vs physical address confusion") Cc: stable@vger.kernel.org Signed-off-by: Peter Oberparleiter Reviewed-by: Heiko Carstens Signed-off-by: Heiko Carstens

s390/cio: Guard PMCW field accesses with dnv check

2026-09-17T04:59:41Z

When PMCW.DNV is 0, no I/O device is associated with the subchannel. However, several code paths access PMCW fields directly from the cached sch->schib without first invoking the update helper. Add explicit DNV validation before accessing PMCW fields from the cached SCHIB to avoid using invalid data. Reported-by: William Bezenah Signed-off-by: Vineeth Vijayan Reviewed-by: Peter Oberparleiter Fixes: 8c58a229688c ("s390/cio: Do not unregister the subchannel based on DNV") Signed-off-by: Heiko Carstens

s390/cio: Check pmcw.dnv before pmcw.ena in I/O entry points

2026-09-17T04:59:41Z

The device number valid (dnv) bit in the PMCW must be checked before acting on any other PMCW fields for IO-type subchannels. A subchannel with dnv=0 has no valid device number associated, making it meaningless to evaluate the enabled (ena) state or issue any I/O instruction against it. Reported-by: William Bezenah Signed-off-by: Vineeth Vijayan Reviewed-by: Peter Oberparleiter Fixes: 8c58a229688c ("s390/cio: Do not unregister the subchannel based on DNV") Signed-off-by: Heiko Carstens

s390/cio: Fix cio_update_schib() to not cache invalid schib

2026-09-17T04:59:41Z

When pmcw.dnv is 0, the contents of all SCHIB fields are unpredictable. Zero sch->schib in that case to prevent subsequent code from making decisions based on unpredictable data. Reported-by: William Bezenah Signed-off-by: Vineeth Vijayan Reviewed-by: Peter Oberparleiter Fixes: 8c58a229688c ("s390/cio: Do not unregister the subchannel based on DNV") Signed-off-by: Heiko Carstens

Merge tag 's390-7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2026-08-23T17:26:44Z

Pull s390 updates from Vasily Gorbik: - Add a cpuidle driver with polling and enabled wait states using the existing CPU idle infrastructure and idle governor to improve latency for frequent sleep/wakeup cycles. Remove the obsolete tick delay heuristic and generic arch_needs_cpu() hook. Add the corresponding driver entry to MAINTAINERS - Add kCFI support using the generic support provided by Clang - Enable Clang CONTEXT_ANALYSIS for various architecture code and for char, PCI, CIO and virtio drivers. Add required lock annotations, exclude unsupported mm helpers and remove conditional PCI locking - Fix secure storage access exception handling and reintroduce DCACHE_WORD_ACCESS previously removed as a workaround - Fix cpum_cf perf crashes when CPUs are brought online while per-task events are active. Allocate and remove per-CPU counter data from CPU hotplug callbacks - Fix a deadlock when an s390dbf debug area is unregistered while one of its debugfs files is being written to - Fix MVIY_PERCPU() with binutils older than 2.39, where an assembler macro silently omitted an instruction needed to repair interrupted operations after CPU migration - Remove/replace cond_resched() calls which are no-ops with the supported s390 preemption models - Fix AP queue depth and maximum message length decoding according to the architecture. Current hardware is not affected, but future hardware could report values which were handled incorrectly - Reflect the configured CPU state in cpu_enabled_mask so deconfigured CPUs are not presented as available for onlining - Restore the vDSO GNU_EH_FRAME program header which was lost when the build switched to direct linker invocation, and mark it read-only - Add SCLP action qualifiers used by Spyre for card initialization, recoverable error and telemetry reporting - Move KMSAN interrupt flag helpers out of line to fix -Wstatic-in-inline build warnings - Use level-specific page table entry accessors for hugetlb entries and ptep_get() when accessing crashed kernel memory in kdump - Make forced AP bus rescans killable so that a user process blocked behind an ongoing scan can still be terminated with SIGKILL - Rework pkey ioctl error paths to remove duplicated cleanup code and avoid freeing error pointers - Allow the protected guest SWIOTLB buffer to be allocated outside the first 2GB. Also enable dynamic SWIOTLB growth and the coherent atomic pool fallback to improve I/O behavior when the initial pool is exhausted - Add program check statistics and spinlock contention tracepoints. Increase the lockdep chain capacity to keep lockdep enabled for complex code paths such as btrfs - Simplify IPL, trap and syscall code and remove the obsolete unistd_32.h generation entry * tag 's390-7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (59 commits) s390/percpu: Fix MVIY_PERCPU() with older binutils s390/debug: Fix deadlock during unregister s390/cpum_cf: Handle CPU hotplug via prepare/dead callbacks s390: Enable CONTEXT_ANALYSIS for various directories s390/mm: Add __context_unsafe() attribute to gmap helper functions s390/mm: Add __context_unsafe() attribute to do_secure_storage_access() s390/sysinfo: Add context analysis attributes s390/irqflags: Add out-of-line definitions of arch_local_irq_*() for KMSAN s390/virtio: Enable CONTEXT_ANALYSIS s390/cio: Enable CONTEXT_ANALYSIS s390/vfio_ccw: Add __must_hold() attribute to vfio_ccw_sch_quiesce() s390/pci: Enable CONTEXT_ANALYSIS s390/pci: Rework __zpci_event_availability() to remove conditional locking s390/pci: Rework __zpci_event_error() to remove conditional locking s390/char: Enable CONTEXT_ANALYSIS s390/con3215: Add __must_hold() attribute to raw3215_make_room() s390/ap: Fix MAPML computation s390/cio: Remove cond_resched() calls s390: Remove cond_resched() calls KVM: s390: Remove cond_resched() calls ...

s390/cio: Enable CONTEXT_ANALYSIS

2026-08-11T14:42:18Z

All cio code passes clang's compile time context analysis. Therefore enable CONTEXT_ANALYSIS. Signed-off-by: Heiko Carstens Acked-by: Christian Borntraeger Signed-off-by: Christian Borntraeger Signed-off-by: Vasily Gorbik

s390/vfio_ccw: Add __must_hold() attribute to vfio_ccw_sch_quiesce()

2026-08-11T14:42:17Z

Add __must_hold() attribute to vfio_ccw_sch_quiesce() in order to let clang's context analysis know that sch->lock must be held on function entry. This can also be easily verified when inspecting the function. Without this annotation this leads to a valid warning when context analysis is enabled: drivers/s390/cio/vfio_ccw_drv.c:55:9: warning: expecting spinlock 'sch->lock' to be held at start of each loop [-Wthread-safety-analysis] 55 | ret = cio_cancel_halt_clear(sch, &iretry); | ^ Signed-off-by: Heiko Carstens Acked-by: Christian Borntraeger Reviewed-by: Matthew Rosato Signed-off-by: Christian Borntraeger Signed-off-by: Vasily Gorbik

s390/cio: Remove cond_resched() calls

2026-08-05T13:16:54Z

Since [1] cond_resched() is a no-op on s390. Remove all calls. [1] commit 7dadeaa6e851 ("sched: Further restrict the preemption modes") Reviewed-by: Peter Oberparleiter Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/vfio_ccw: Implement a crw lock

2026-07-30T17:50:48Z

Unlike the channel_program struct, which covers synchronous I/O submissions and asynchronous interrupts, the CRW region relies exclusively on asynchronous events coming from hardware. Implement a lock to manage the list of those payloads, to ensure they are read cohesively. Fixes: 3f02cb2fd9d2 ("vfio-ccw: Wire up the CRW irq and CRW region") Cc: stable@vger.kernel.org Reviewed-by: Matthew Rosato Reviewed-by: Farhan Ali Signed-off-by: Eric Farman Signed-off-by: Christian Borntraeger