kernel/linux.git/arch/s390, branch v6.18.42

s390/ptff: Export ptff_function_mask[]

2026-08-03T09:22:04+00:00

commit 9de445d8296a7f2b011ebb5834fdc94dcda5c778 upstream. Export the ptff_function_mask to make ptff_query() usable in modules. Signed-off-by: Sven Schnelle Acked-by: Heiko Carstens Link: https://patch.msgid.link/20260714130342.1971700-2-svens@linux.ibm.com Signed-off-by: Jakub Kicinski Cc: Jiri Slaby Signed-off-by: Greg Kroah-Hartman

s390/checksum: Fix csum_partial() without vector facility

2026-08-03T09:21:34+00:00

[ Upstream commit 4bb06b60d982355e22647b3d12d6619419f8c1fa ] Currently csum_partial() calls csum_copy() with copy=false and dst=NULL. On machines without the vector facility, csum_copy() falls back to cksm(dst, ...), causing the checksum to be calculated from address zero instead of the source buffer. The VX implementation already checksums data loaded from src. Make the fallback do the same by passing src to cksm(). Fixes: dcd3e1de9d17 ("s390/checksum: provide csum_partial_copy_nocheck()") Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Sasha Levin

s390/mm: Fix type mismatch in get_align_mask().

2026-07-24T14:17:16+00:00

commit ec84aad4c3594307d103af563991b4415ac5c8ab upstream. Commit 86f48f922ba79 ("s390/mmap: disable mmap alignment when randomize_va_space = 0") introduced get_align_mask() with return type of 'int', while the target field 'info.align_mask' in struct vm_unmapped_area_info is 'unsigned long'. With currently used masks, this should not cause truncation issues, but fix it and return 'unsigned long' to avoid future problems. Fixes: 86f48f922ba79 ("s390/mmap: disable mmap alignment when randomize_va_space = 0") Cc: stable@vger.kernel.org # v6.9+ Signed-off-by: Gerald Schaefer Reviewed-by: Sven Schnelle Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman

s390/diag: Add missing array_index_nospec() call to memtop_get_page_count()

2026-07-24T14:17:16+00:00

commit b7577fe4c47a31ca7c99714c53244a44af03cdfe upstream. 'level' is user space controlled and used to read from an array. Add the missing array_index_nospec() call to prevent speculative execution. Cc: stable@vger.kernel.org Fixes: 0d30871739ab ("s390/diag: Add memory topology information via diag310") Signed-off-by: Heiko Carstens Reviewed-by: Mete Durlu Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman

s390/perf_cpum_cf: Add missing array_index_nospec() to __hw_perf_event_init()

2026-07-24T14:16:57+00:00

commit 49145bce539117db4b6e9e83c0e5ef528e361050 upstream. ev variable is userspace controlled via event->attr.config and used as an array index after bounds checking, but without speculation barriers. Add the missing array_index_nospec() call to prevent speculative execution. Cc: stable@vger.kernel.org Fixes: 212188a596d1 ("[S390] perf: add support for s390x CPU counters") Signed-off-by: Sumanth Korikkar Reviewed-by: Ilya Leoshkevich Acked-by: Thomas Richter Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman

KVM: s390: pci: Fix handling of AIF enable without AISB

2026-07-24T14:16:53+00:00

commit 3e3aa6da87d30a0064a17b836685cd43c90a3572 upstream. When a guest seeks to register IRQs without a summary bit specified, ensure that the associated GAITE then stores 0 for the guest AISB location instead of virt_to_phys(page_address(NULL)). Fixes: 3c5a1b6f0a18 ("KVM: s390: pci: provide routines for enabling/disabling interrupt forwarding") Cc: stable@vger.kernel.org Reviewed-by: Farhan Ali Signed-off-by: Matthew Rosato Signed-off-by: Christian Borntraeger Signed-off-by: Greg Kroah-Hartman

KVM: s390: pci: Fix GISC refcount leak on AIF enable failure

2026-07-24T14:16:53+00:00

commit 7b69729046a4c58f4cb457184e5ac4aaa179bff4 upstream. kvm_s390_gisc_register() registers the guest ISC before pinning the guest interrupt forwarding pages and allocating the AISB bit. If any of the later setup steps fails, the function unwinds the pinned pages and other local state, but does not unregister the GISC reference. Add the missing kvm_s390_gisc_unregister() to the error unwind path. Fixes: 3c5a1b6f0a18 ("KVM: s390: pci: provide routines for enabling/disabling interrupt forwarding") Cc: stable@vger.kernel.org Signed-off-by: Haoxiang Li Reviewed-by: Matthew Rosato Tested-by: Matthew Rosato Acked-by: Claudio Imbrenda Reviewed-by: Christian Borntraeger Signed-off-by: Claudio Imbrenda Message-ID: <20260624061910.2794734-1-haoxiang_li2024@163.com> Signed-off-by: Christian Borntraeger Signed-off-by: Greg Kroah-Hartman

s390/process: Fix kernel thread function pointer type

2026-07-24T14:16:08+00:00

[ Upstream commit d0478f5d3cba1095bfdeb43a9b063c10cdebef14 ] In case of a kernel thread __ret_from_fork() calls the specified function indirectly. Fix the kernel thread function pointer, since kernel threads return an int instead of void. Fixes: 56e62a737028 ("s390: convert to generic entry") Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Alexander Gordeev Signed-off-by: Sasha Levin

s390: Revert support for DCACHE_WORD_ACCESS

2026-07-18T14:53:20+00:00

commit 37540b8c287fc817bdbd0c62bb75ad6eab0e5d03 upstream. load_unaligned_zeropad() reads eight bytes from unaligned addresses and may cross page boundaries. It handles exceptions which may happen if reading from the second page results in an exception. For pages which are donated to the Ultravisor for secure execution purposes the do_secure_storage_access() exception handler however does not handle such exceptions correctly. Such an exception may result in an endless exception loop which will never be resolved. An attempt to fix this [1] turned out to be not sufficient. For now revert load_unaligned_zeropad() until this problem has been resolved in a proper way. Note that the implementation of load_unaligned_zeropad() itself is correct. The revert is just a temporary workaround until there is complete fix for secure storage access exceptions. [1] commit b00be77302d7 ("s390/mm: Add missing secure storage access fixups for donated memory") Fixes: 802ba53eefc5 ("s390: add support for DCACHE_WORD_ACCESS") Cc: stable@vger.kernel.org Acked-by: Christian Borntraeger Signed-off-by: Heiko Carstens Signed-off-by: Alexander Gordeev Signed-off-by: Greg Kroah-Hartman

ring-buffer: Flush and stop persistent ring buffer on panic

2026-06-01T15:50:44+00:00

commit a494d3c8d5392bcdff83c2a593df0c160ff9f322 upstream. On real hardware, panic and machine reboot may not flush hardware cache to memory. This means the persistent ring buffer, which relies on a coherent state of memory, may not have its events written to the buffer and they may be lost. Moreover, there may be inconsistency with the counters which are used for validation of the integrity of the persistent ring buffer which may cause all data to be discarded. To avoid this issue, stop recording of the ring buffer on panic and flush the cache of the ring buffer's memory. Fixes: e645535a954a ("tracing: Add option to use memmapped memory for trace boot instance") Cc: stable@vger.kernel.org Cc: Will Deacon Cc: Mathieu Desnoyers Cc: Ian Rogers Link: https://patch.msgid.link/177751969602.2136606.12031934362587643488.stgit@mhiramat.tok.corp.google.com Signed-off-by: Masami Hiramatsu (Google) Acked-by: Catalin Marinas Acked-by: Geert Uytterhoeven Signed-off-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman