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2026-04-28s390/debug: Reject zero-length input in debug_input_flush_fn()Vasily Gorbik
debug_input_flush_fn() always copies one byte from the userspace buffer with copy_from_user() regardless of the supplied write length. A zero-length write therefore reads one byte beyond the caller's buffer. If the stale byte happens to be '-' or a digit the debug log is silently flushed. With an unmapped buffer the call returns -EFAULT. Reject zero-length writes before copying from userspace. Cc: stable@vger.kernel.org # v5.10+ Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2026-04-28s390/debug: Reject zero-length input before trimming a newlinePengpeng Hou
debug_get_user_string() duplicates the userspace buffer with memdup_user_nul() and then unconditionally looks at buffer[user_len - 1] to strip a trailing newline. A zero-length write reaches this helper unchanged, so the newline trim reads before the start of the allocated buffer. Reject empty writes before accessing the last input byte. Fixes: 66a464dbc8e0 ("[PATCH] s390: debug feature changes") Cc: stable@vger.kernel.org Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Reviewed-by: Vasily Gorbik <gor@linux.ibm.com> Tested-by: Vasily Gorbik <gor@linux.ibm.com> Link: https://lore.kernel.org/r/20260417073530.96002-1-pengpeng@iscas.ac.cn Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2026-04-17Merge tag 'integrity-v7.1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity Pull integrity updates from Mimi Zohar: "There are two main changes, one feature removal, some code cleanup, and a number of bug fixes. Main changes: - Detecting secure boot mode was limited to IMA. Make detecting secure boot mode accessible to EVM and other LSMs - IMA sigv3 support was limited to fsverity. Add IMA sigv3 support for IMA regular file hashes and EVM portable signatures Remove: - Remove IMA support for asychronous hash calculation originally added for hardware acceleration Cleanup: - Remove unnecessary Kconfig CONFIG_MODULE_SIG and CONFIG_KEXEC_SIG tests - Add descriptions of the IMA atomic flags Bug fixes: - Like IMA, properly limit EVM "fix" mode - Define and call evm_fix_hmac() to update security.evm - Fallback to using i_version to detect file change for filesystems that do not support STATX_CHANGE_COOKIE - Address missing kernel support for configured (new) TPM hash algorithms - Add missing crypto_shash_final() return value" * tag 'integrity-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity: evm: Enforce signatures version 3 with new EVM policy 'bit 3' integrity: Allow sigv3 verification on EVM_XATTR_PORTABLE_DIGSIG ima: add support to require IMA sigv3 signatures ima: add regular file data hash signature version 3 support ima: Define asymmetric_verify_v3() to verify IMA sigv3 signatures ima: remove buggy support for asynchronous hashes integrity: Eliminate weak definition of arch_get_secureboot() ima: Add code comments to explain IMA iint cache atomic_flags ima_fs: Correctly create securityfs files for unsupported hash algos ima: check return value of crypto_shash_final() in boot aggregate ima: Define and use a digest_size field in the ima_algo_desc structure powerpc/ima: Drop unnecessary check for CONFIG_MODULE_SIG ima: efi: Drop unnecessary check for CONFIG_MODULE_SIG/CONFIG_KEXEC_SIG ima: fallback to using i_version to detect file change evm: fix security.evm for a file with IMA signature s390: Drop unnecessary CONFIG_IMA_SECURE_AND_OR_TRUSTED_BOOT evm: Don't enable fix mode when secure boot is enabled integrity: Make arch_ima_get_secureboot integrity-wide
2026-04-14Merge tag 'bpf-next-7.1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Pull bpf updates from Alexei Starovoitov: - Welcome new BPF maintainers: Kumar Kartikeya Dwivedi, Eduard Zingerman while Martin KaFai Lau reduced his load to Reviwer. - Lots of fixes everywhere from many first time contributors. Thank you All. - Diff stat is dominated by mechanical split of verifier.c into multiple components: - backtrack.c: backtracking logic and jump history - states.c: state equivalence - cfg.c: control flow graph, postorder, strongly connected components - liveness.c: register and stack liveness - fixups.c: post-verification passes: instruction patching, dead code removal, bpf_loop inlining, finalize fastcall 8k line were moved. verifier.c still stands at 20k lines. Further refactoring is planned for the next release. - Replace dynamic stack liveness with static stack liveness based on data flow analysis. This improved the verification time by 2x for some programs and equally reduced memory consumption. New logic is in liveness.c and supported by constant folding in const_fold.c (Eduard Zingerman, Alexei Starovoitov) - Introduce BTF layout to ease addition of new BTF kinds (Alan Maguire) - Use kmalloc_nolock() universally in BPF local storage (Amery Hung) - Fix several bugs in linked registers delta tracking (Daniel Borkmann) - Improve verifier support of arena pointers (Emil Tsalapatis) - Improve verifier tracking of register bounds in min/max and tnum domains (Harishankar Vishwanathan, Paul Chaignon, Hao Sun) - Further extend support for implicit arguments in the verifier (Ihor Solodrai) - Add support for nop,nop5 instruction combo for USDT probes in libbpf (Jiri Olsa) - Support merging multiple module BTFs (Josef Bacik) - Extend applicability of bpf_kptr_xchg (Kaitao Cheng) - Retire rcu_trace_implies_rcu_gp() (Kumar Kartikeya Dwivedi) - Support variable offset context access for 'syscall' programs (Kumar Kartikeya Dwivedi) - Migrate bpf_task_work and dynptr to kmalloc_nolock() (Mykyta Yatsenko) - Fix UAF in in open-coded task_vma iterator (Puranjay Mohan) * tag 'bpf-next-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (241 commits) selftests/bpf: cover short IPv4/IPv6 inputs with adjust_room bpf: reject short IPv4/IPv6 inputs in bpf_prog_test_run_skb selftests/bpf: Use memfd_create instead of shm_open in cgroup_iter_memcg selftests/bpf: Add test for cgroup storage OOB read bpf: Fix OOB in pcpu_init_value selftests/bpf: Fix reg_bounds to match new tnum-based refinement selftests/bpf: Add tests for non-arena/arena operations bpf: Allow instructions with arena source and non-arena dest registers bpftool: add missing fsession to the usage and docs of bpftool docs/bpf: add missing fsession attach type to docs bpf: add missing fsession to the verifier log bpf: Move BTF checking logic into check_btf.c bpf: Move backtracking logic to backtrack.c bpf: Move state equivalence logic to states.c bpf: Move check_cfg() into cfg.c bpf: Move compute_insn_live_regs() into liveness.c bpf: Move fixup/post-processing logic from verifier.c into fixups.c bpf: Simplify do_check_insn() bpf: Move checks for reserved fields out of the main pass bpf: Delete unused variable ...
2026-04-14Merge tag 'modules-7.1-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux Pull module updates from Sami Tolvanen: "Kernel symbol flags: - Replace the separate *_gpl symbol sections (__ksymtab_gpl and __kcrctab_gpl) with a unified symbol table and a new __kflagstab section. This section stores symbol flags, such as the GPL-only flag, as an 8-bit bitset for each exported symbol. This is a cleanup that simplifies symbol lookup in the module loader by avoiding table fragmentation and will allow a cleaner way to add more flags later if needed. Module signature UAPI: - Move struct module_signature to the UAPI headers to allow reuse by tools outside the kernel proper, such as kmod and scripts/sign-file. This also renames a few constants for clarity and drops unused signature types as preparation for hash-based module integrity checking work that's in progress. Sysfs: - Add a /sys/module/<module>/import_ns sysfs attribute to show the symbol namespaces imported by loaded modules. This makes it easier to verify driver API access at runtime on systems that care about such things (e.g. Android). Cleanups and fixes: - Force sh_addr to 0 for all sections in module.lds. This prevents non-zero section addresses when linking modules with 'ld.bfd -r', which confused elfutils. - Fix a memory leak of charp module parameters on module unload when the kernel is configured with CONFIG_SYSFS=n. - Override the -EEXIST error code returned by module_init() to userspace. This prevents confusion with the errno reserved by the module loader to indicate that a module is already loaded. - Simplify the warning message and drop the stack dump on positive returns from module_init(). - Drop unnecessary extern keywords from function declarations and synchronize parse_args() arguments with their implementation" * tag 'modules-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux: (23 commits) module: Simplify warning on positive returns from module_init() module: Override -EEXIST module return documentation: remove references to *_gpl sections module: remove *_gpl sections from vmlinux and modules module: deprecate usage of *_gpl sections in module loader module: use kflagstab instead of *_gpl sections module: populate kflagstab in modpost module: add kflagstab section to vmlinux and modules module: define ksym_flags enumeration to represent kernel symbol flags selftests/bpf: verify_pkcs7_sig: Use 'struct module_signature' from the UAPI headers sign-file: use 'struct module_signature' from the UAPI headers tools uapi headers: add linux/module_signature.h module: Move 'struct module_signature' to UAPI module: Give MODULE_SIG_STRING a more descriptive name module: Give 'enum pkey_id_type' a more specific name module: Drop unused signature types extract-cert: drop unused definition of PKEY_ID_PKCS7 docs: symbol-namespaces: mention sysfs attribute module: expose imported namespaces via sysfs module: Remove extern keyword from param prototypes ...
2026-04-13Merge tag 'hardening-v7.1-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull hardening updates from Kees Cook: - randomize_kstack: Improve implementation across arches (Ryan Roberts) - lkdtm/fortify: Drop unneeded FORTIFY_STR_OBJECT test - refcount: Remove unused __signed_wrap function annotations * tag 'hardening-v7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: lkdtm/fortify: Drop unneeded FORTIFY_STR_OBJECT test refcount: Remove unused __signed_wrap function annotations randomize_kstack: Unify random source across arches randomize_kstack: Maintain kstack_offset per task
2026-04-03Merge tag 's390-7.0-7' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 fixes from Vasily Gorbik: - Fix a memory leak in the zcrypt driver where the AP message buffer for clear key RSA requests was allocated twice, once by the caller and again locally, causing the first allocation to never be freed - Fix the cpum_sf perf sampling rate overflow adjustment to clamp the recalculated rate to the hardware maximum, preventing exceptions on heavily loaded systems running with HZ=1000 * tag 's390-7.0-7' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/zcrypt: Fix memory leak with CCA cards used as accelerator s390/cpum_sf: Cap sampling rate to prevent lsctl exception
2026-04-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 7.0-rc6+Alexei Starovoitov
Cross-merge BPF and other fixes after downstream PR. Minor conflict in kernel/bpf/verifier.c Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-03-28Merge tag 's390-7.0-6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 fixes from Vasily Gorbik: - Add array_index_nospec() to syscall dispatch table lookup to prevent limited speculative out-of-bounds access with user-controlled syscall number - Mark array_index_mask_nospec() __always_inline since GCC may emit an out-of-line call instead of the inline data dependency sequence the mitigation relies on - Clear r12 on kernel entry to prevent potential speculative use of user value in system_call, ext/io/mcck interrupt handlers * tag 's390-7.0-6' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/entry: Scrub r12 register on kernel entry s390/syscalls: Add spectre boundary for syscall dispatch table s390/barrier: Make array_index_mask_nospec() __always_inline
2026-03-28s390/entry: Scrub r12 register on kernel entryVasily Gorbik
Before commit f33f2d4c7c80 ("s390/bp: remove TIF_ISOLATE_BP"), all entry handlers loaded r12 with the current task pointer (lg %r12,__LC_CURRENT) for use by the BPENTER/BPEXIT macros. That commit removed TIF_ISOLATE_BP, dropping both the branch prediction macros and the r12 load, but did not add r12 to the register clearing sequence. Add the missing xgr %r12,%r12 to make the register scrub consistent across all entry points. Fixes: f33f2d4c7c80 ("s390/bp: remove TIF_ISOLATE_BP") Cc: stable@kernel.org Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-03-28s390/syscalls: Add spectre boundary for syscall dispatch tableGreg Kroah-Hartman
The s390 syscall number is directly controlled by userspace, but does not have an array_index_nospec() boundary to prevent access past the syscall function pointer tables. Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Arnd Bergmann <arnd@arndb.de> Fixes: 56e62a737028 ("s390: convert to generic entry") Cc: stable@kernel.org Assisted-by: gkh_clanker_2000 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Vasily Gorbik <gor@linux.ibm.com> Link: https://lore.kernel.org/r/2026032404-sterling-swoosh-43e6@gregkh Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-03-24randomize_kstack: Unify random source across archesRyan Roberts
Previously different architectures were using random sources of differing strength and cost to decide the random kstack offset. A number of architectures (loongarch, powerpc, s390, x86) were using their timestamp counter, at whatever the frequency happened to be. Other arches (arm64, riscv) were using entropy from the crng via get_random_u16(). There have been concerns that in some cases the timestamp counters may be too weak, because they can be easily guessed or influenced by user space. And get_random_u16() has been shown to be too costly for the level of protection kstack offset randomization provides. So let's use a common, architecture-agnostic source of entropy; a per-cpu prng, seeded at boot-time from the crng. This has a few benefits: - We can remove choose_random_kstack_offset(); That was only there to try to make the timestamp counter value a bit harder to influence from user space [*]. - The architecture code is simplified. All it has to do now is call add_random_kstack_offset() in the syscall path. - The strength of the randomness can be reasoned about independently of the architecture. - Arches previously using get_random_u16() now have much faster syscall paths, see below results. [*] Additionally, this gets rid of some redundant work on s390 and x86. Before this patch, those architectures called choose_random_kstack_offset() under arch_exit_to_user_mode_prepare(), which is also called for exception returns to userspace which were *not* syscalls (e.g. regular interrupts). Getting rid of choose_random_kstack_offset() avoids a small amount of redundant work for the non-syscall cases. In some configurations, add_random_kstack_offset() will now call instrumentable code, so for a couple of arches, I have moved the call a bit later to the first point where instrumentation is allowed. This doesn't impact the efficacy of the mechanism. There have been some claims that a prng may be less strong than the timestamp counter if not regularly reseeded. But the prng has a period of about 2^113. So as long as the prng state remains secret, it should not be possible to guess. If the prng state can be accessed, we have bigger problems. Additionally, we are only consuming 6 bits to randomize the stack, so there are only 64 possible random offsets. I assert that it would be trivial for an attacker to brute force by repeating their attack and waiting for the random stack offset to be the desired one. The prng approach seems entirely proportional to this level of protection. Performance data are provided below. The baseline is v6.18 with rndstack on for each respective arch. (I)/(R) indicate statistically significant improvement/regression. arm64 platform is AWS Graviton3 (m7g.metal). x86_64 platform is AWS Sapphire Rapids (m7i.24xlarge): +-----------------+--------------+---------------+---------------+ | Benchmark | Result Class | per-cpu-prng | per-cpu-prng | | | | arm64 (metal) | x86_64 (VM) | +=================+==============+===============+===============+ | syscall/getpid | mean (ns) | (I) -9.50% | (I) -17.65% | | | p99 (ns) | (I) -59.24% | (I) -24.41% | | | p99.9 (ns) | (I) -59.52% | (I) -28.52% | +-----------------+--------------+---------------+---------------+ | syscall/getppid | mean (ns) | (I) -9.52% | (I) -19.24% | | | p99 (ns) | (I) -59.25% | (I) -25.03% | | | p99.9 (ns) | (I) -59.50% | (I) -28.17% | +-----------------+--------------+---------------+---------------+ | syscall/invalid | mean (ns) | (I) -10.31% | (I) -18.56% | | | p99 (ns) | (I) -60.79% | (I) -20.06% | | | p99.9 (ns) | (I) -61.04% | (I) -25.04% | +-----------------+--------------+---------------+---------------+ I tested an earlier version of this change on x86 bare metal and it showed a smaller but still significant improvement. The bare metal system wasn't available this time around so testing was done in a VM instance. I'm guessing the cost of rdtsc is higher for VMs. Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Link: https://patch.msgid.link/20260303150840.3789438-3-ryan.roberts@arm.com Signed-off-by: Kees Cook <kees@kernel.org>
2026-03-24module: Give MODULE_SIG_STRING a more descriptive nameThomas Weißschuh
The purpose of the constant it is not entirely clear from its name. As this constant is going to be exposed in a UAPI header, give it a more specific name for clarity. As all its users call it 'marker', use that wording in the constant itself. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Reviewed-by: Petr Pavlu <petr.pavlu@suse.com> Reviewed-by: Nicolas Schier <nsc@kernel.org> Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
2026-03-24module: Give 'enum pkey_id_type' a more specific nameThomas Weißschuh
This enum originates in generic cryptographic code and has a very generic name. Nowadays it is only used for module signatures. As this enum is going to be exposed in a UAPI header, give it a more specific name for clarity and consistency. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Reviewed-by: Petr Pavlu <petr.pavlu@suse.com> Reviewed-by: Nicolas Schier <nsc@kernel.org> Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
2026-03-24s390/cpum_sf: Cap sampling rate to prevent lsctl exceptionThomas Richter
commit fcc43a7e294f ("s390/configs: Set HZ=1000") changed the interrupt frequency of the system. On machines with heavy load and many perf event overflows, this might lead to an exception. Dmesg displays these entries: [112.242542] cpum_sf: Loading sampling controls failed: op 1 err -22 One line per CPU online. The root cause is the CPU Measurement sampling facility overflow adjustment. Whenever an overflow (too much samples per tick) occurs, the sampling rate is adjusted and increased. This was done without observing the maximum sampling rate limit. When the current sampling interval is higher than the maximum sampling rate limit, the lsctl instruction raises an exception. The error messages is the result of such an exception. Observe the upper limit when the new sampling rate is recalculated. Cc: stable@vger.kernel.org Fixes: 39d4a501a9ef ("s390/cpum_sf: Adjust sampling interval to avoid hitting sample limits") Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Reviewed-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-03-24Merge tag 'kvm-s390-master-7.0-1' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD KVM: s390: Fixes for 7.0 - fix deadlock in new memory management - handle kernel faults on donated memory properly - fix bounds checking for irq routing + selftest - fix invalid machine checks + logging
2026-03-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 7.0-rc5Alexei Starovoitov
Cross-merge BPF and other fixes after downstream PR. Minor conflicts in: tools/testing/selftests/bpf/progs/exceptions_fail.c tools/testing/selftests/bpf/progs/verifier_bounds.c Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-03-16KVM: s390: vsie: Avoid injecting machine check on signalChristian Borntraeger
The recent XFER_TO_GUEST_WORK change resulted in a situation, where the vsie code would interpret a signal during work as a machine check during SIE as both use the EINTR return code. The exit_reason of the sie64a function has nothing to do with the kvm_run exit_reason. Rename it and define a specific code for machine checks instead of abusing -EINTR. rename exit_reason into sie_return to avoid the naming conflict and change the code flow in vsie.c to have a separate variable for rc and sie_return. Fixes: 2bd1337a1295e ("KVM: s390: Use generic VIRT_XFER_TO_GUEST_WORK functions") Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
2026-03-13Merge tag 's390-7.0-5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 fixes from Vasily Gorbik: - Revert IRQ entry/exit path optimization that incorrectly cleared some PSW bits before irqentry_exit(), causing boot failures with linux-next and HRTIMER_REARM_DEFERRED (which only uncovered the problem) - Fix zcrypt code to show CCA card serial numbers even when the default crypto domain is offline by selecting any domain available, preventing empty sysfs entries * tag 's390-7.0-5' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/zcrypt: Enable AUTOSEL_DOM for CCA serialnr sysfs attribute s390: Revert "s390/irq/idle: Remove psw bits early"
2026-03-13integrity: Eliminate weak definition of arch_get_secureboot()Nathan Chancellor
security/integrity/secure_boot.c contains a single __weak function, which breaks recordmcount when building with clang: $ make -skj"$(nproc)" ARCH=powerpc LLVM=1 ppc64_defconfig security/integrity/secure_boot.o Cannot find symbol for section 2: .text. security/integrity/secure_boot.o: failed Introduce a Kconfig symbol, CONFIG_HAVE_ARCH_GET_SECUREBOOT, to indicate that an architecture provides a definition of arch_get_secureboot(). Provide a static inline stub when this symbol is not defined to achieve the same effect as the __weak function, allowing secure_boot.c to be removed altogether. Move the s390 definition of arch_get_secureboot() out of the CONFIG_KEXEC_FILE block to ensure it is always available, as it does not actually depend on KEXEC_FILE. Reported-by: Arnd Bergmann <arnd@arndb.de> Fixes: 31a6a07eefeb ("integrity: Make arch_ima_get_secureboot integrity-wide") Signed-off-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2026-03-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 7.0-rc3Alexei Starovoitov
Cross-merge BPF and other fixes after downstream PR. No conflicts. Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-03-07s390: Revert "s390/irq/idle: Remove psw bits early"Heiko Carstens
This reverts commit d8b5cf9c63143fae54a734c41e3bb55cf3f365c7. Mikhail Zaslonko reported that linux-next doesn't boot anymore [2]. Reason for this is recent change [2] was supposed to slightly optimize the irq entry/exit path by removing some psw bits early in case of an idle exit. This however is incorrect since irqentry_exit() requires the correct old psw state at irq entry. Otherwise the embedded regs_irqs_disabled() will not provide the correct result. With linux-next and HRTIMER_REARM_DEFERRED this leads to the observed boot problems, however the commit is broken in any case. Revert the commit which introduced this. Thanks to Peter Zijlstra for pointing out that this is a bug in the s390 entry code. Fixes: d8b5cf9c6314 ("s390/irq/idle: Remove psw bits early") [1] Reported-by: Mikhail Zaslonko <zaslonko@linux.ibm.com> Reported-by: Peter Zijlstra <peterz@infradead.org> Closes: https://lore.kernel.org/r/af549a19-db99-4b16-8511-bf315177a13e@linux.ibm.com/ [2] Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Mikhail Zaslonko <zaslonko@linux.ibm.com> Tested-by: Mikhail Zaslonko <zaslonko@linux.ibm.com> Acked-by: Vasily Gorbik <gor@linux.ibm.com> Link: https://lore.kernel.org/r/20260306111919.362559-1-hca@linux.ibm.com Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-03-06Merge tag 'kbuild-fixes-7.0-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux Pull Kbuild fixes from Nathan Chancellor: - Split out .modinfo section from ELF_DETAILS macro, as that macro may be used in other areas that expect to discard .modinfo, breaking certain image layouts - Adjust genksyms parser to handle optional attributes in certain declarations, necessary after commit 07919126ecfc ("netfilter: annotate NAT helper hook pointers with __rcu") - Include resolve_btfids in external module build created by scripts/package/install-extmod-build when it may be run on external modules - Avoid removing objtool binary with 'make clean', as it is required for external module builds * tag 'kbuild-fixes-7.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux: kbuild: Leave objtool binary around with 'make clean' kbuild: install-extmod-build: Package resolve_btfids if necessary genksyms: Fix parsing a declarator with a preceding attribute kbuild: Split .modinfo out from ELF_DETAILS
2026-03-05s390: Drop unnecessary CONFIG_IMA_SECURE_AND_OR_TRUSTED_BOOTCoiby Xu
Commit b5ca117365d9 ("ima: prevent kexec_load syscall based on runtime secureboot flag") and commit 268a78404973 ("s390/kexec_file: Disable kexec_load when IPLed secure") disabled the kexec_load syscall based on the secureboot mode. Commit 9e2b4be377f0 ("ima: add a new CONFIG for loading arch-specific policies") needed to detect the secure boot mode, not to load an IMA architecture specific policy. Since there is the new CONFIG_INTEGRITY_SECURE_BOOT, drop CONFIG_IMA_SECURE_AND_OR_TRUSTED_BOOT for s390. Signed-off-by: Coiby Xu <coxu@redhat.com> Tested-by: Alexander Egorenkov <egorenar@linux.ibm.com> [Vasily Gorbik: Fix missing arch_get_secureboot() prototype warning] link: https://lore.kernel.org/linux-integrity/c00-01.ttbfdx5@ub.hpns/ Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2026-03-05integrity: Make arch_ima_get_secureboot integrity-wideCoiby Xu
EVM and other LSMs need the ability to query the secure boot status of the system, without directly calling the IMA arch_ima_get_secureboot function. Refactor the secure boot status check into a general function named arch_get_secureboot. Reported-and-suggested-by: Mimi Zohar <zohar@linux.ibm.com> Suggested-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Coiby Xu <coxu@redhat.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2026-03-03s390: Introduce bpf_get_lowcore() kfuncIlya Leoshkevich
Implementing BPF version of preempt_count() requires accessing lowcore from BPF. Since lowcore can be relocated, open-coding (struct lowcore *)0 does not work, so add a kfunc. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Link: https://lore.kernel.org/r/20260217160813.100855-2-iii@linux.ibm.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-02-26kbuild: Split .modinfo out from ELF_DETAILSNathan Chancellor
Commit 3e86e4d74c04 ("kbuild: keep .modinfo section in vmlinux.unstripped") added .modinfo to ELF_DETAILS while removing it from COMMON_DISCARDS, as it was needed in vmlinux.unstripped and ELF_DETAILS was present in all architecture specific vmlinux linker scripts. While this shuffle is fine for vmlinux, ELF_DETAILS and COMMON_DISCARDS may be used by other linker scripts, such as the s390 and x86 compressed boot images, which may not expect to have a .modinfo section. In certain circumstances, this could result in a bootloader failing to load the compressed kernel [1]. Commit ddc6cbef3ef1 ("s390/boot/vmlinux.lds.S: Ensure bzImage ends with SecureBoot trailer") recently addressed this for the s390 bzImage but the same bug remains for arm, parisc, and x86. The presence of .modinfo in the x86 bzImage was the root cause of the issue worked around with commit d50f21091358 ("kbuild: align modinfo section for Secureboot Authenticode EDK2 compat"). misc.c in arch/x86/boot/compressed includes lib/decompress_unzstd.c, which in turn includes lib/xxhash.c and its MODULE_LICENSE / MODULE_DESCRIPTION macros due to the STATIC definition. Split .modinfo out from ELF_DETAILS into its own macro and handle it in all vmlinux linker scripts. Discard .modinfo in the places where it was previously being discarded from being in COMMON_DISCARDS, as it has never been necessary in those uses. Cc: stable@vger.kernel.org Fixes: 3e86e4d74c04 ("kbuild: keep .modinfo section in vmlinux.unstripped") Reported-by: Ed W <lists@wildgooses.com> Closes: https://lore.kernel.org/587f25e0-a80e-46a5-9f01-87cb40cfa377@wildgooses.com/ [1] Tested-by: Ed W <lists@wildgooses.com> # x86_64 Link: https://patch.msgid.link/20260225-separate-modinfo-from-elf-details-v1-1-387ced6baf4b@kernel.org Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-02-25s390/kexec: Disable stack protector in s390_reset_system()Vasily Gorbik
s390_reset_system() calls set_prefix(0), which switches back to the absolute lowcore. At that point the stack protector canary no longer matches the canary from the lowcore the function was entered with, so the stack check fails. Mark s390_reset_system() __no_stack_protector. This is safe here since its callers (__do_machine_kdump() and __do_machine_kexec()) are effectively no-return and fall back to disabled_wait() on failure. Fixes: f5730d44e05e ("s390: Add stackprotector support") Reported-by: Nikita Dubrovskii <nikita@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-02-25s390/vtime: Use lockdep_assert_irqs_disabled() instead of BUG_ON()Heiko Carstens
Use lockdep_assert_irqs_disabled() instead of BUG_ON(). This avoids crashing the kernel, and generates better code if CONFIG_PROVE_LOCKING is disabled. Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-02-25s390/vtime: Use __this_cpu_read() / get rid of READ_ONCE()Heiko Carstens
do_account_vtime() runs always with interrupts disabled, therefore use __this_cpu_read() instead of this_cpu_read() to get rid of a pointless preempt_disable() / preempt_enable() pair. Also there are no concurrent writers to the cpu time accounting fields in lowcore. Therefore get rid of READ_ONCE() usages. Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-02-25s390/irq/idle: Remove psw bits earlyHeiko Carstens
Remove wait, io, external interrupt bits early in do_io_irq()/do_ext_irq() when previous context was idle. This saves one conditional branch and is closer to the original old assembly code. Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-02-25s390/idle: Inline update_timer_idle()Heiko Carstens
Inline update_timer_idle() again to avoid an extra function call. This way the generated code is close to old assembler version again. Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-02-25s390/idle: Slightly optimize idle time accountingHeiko Carstens
Slightly optimize account_idle_time_irq() and update_timer_idle(): - Use fast single instruction __atomic64() primitives to update per cpu idle_time and idle_count, instead of READ_ONCE() / WRITE_ONCE() pairs - stcctm() is an inline assembly with a full memory barrier. This leads to a not necessary extra dereference of smp_cpu_mtid in update_timer_idle(). Avoid this and read smp_cpu_mtid into a variable - Use __this_cpu_add() instead of this_cpu_add() to avoid disabling / enabling of preemption several times in a loop in update_timer_idle(). Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-02-25s390/idle: Add comment for non obvious codeHeiko Carstens
Add a comment to update_timer_idle() which describes why wall time (not steal time) is added to steal_timer. This is not obvious and was reported by Frederic Weisbecker. Reported-by: Frederic Weisbecker <frederic@kernel.org> Closes: https://lore.kernel.org/all/aXEVM-04lj0lntMr@localhost.localdomain/ Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-02-25s390/vtime: Fix virtual timer forwardingHeiko Carstens
Since delayed accounting of system time [1] the virtual timer is forwarded by do_account_vtime() but also vtime_account_kernel(), vtime_account_softirq(), and vtime_account_hardirq(). This leads to double accounting of system, guest, softirq, and hardirq time. Remove accounting from the vtime_account*() family to restore old behavior. There is only one user of the vtimer interface, which might explain why nobody noticed this so far. Fixes: b7394a5f4ce9 ("sched/cputime, s390: Implement delayed accounting of system time") [1] Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-02-25s390/idle: Fix cpu idle exit cpu time accountingHeiko Carstens
With the conversion to generic entry [1] cpu idle exit cpu time accounting was converted from assembly to C. This introduced an reversed order of cpu time accounting. On cpu idle exit the current accounting happens with the following call chain: -> do_io_irq()/do_ext_irq() -> irq_enter_rcu() -> account_hardirq_enter() -> vtime_account_irq() -> vtime_account_kernel() vtime_account_kernel() accounts the passed cpu time since last_update_timer as system time, and updates last_update_timer to the current cpu timer value. However the subsequent call of -> account_idle_time_irq() will incorrectly subtract passed cpu time from timer_idle_enter to the updated last_update_timer value from system_timer. Then last_update_timer is updated to a sys_enter_timer, which means that last_update_timer goes back in time. Subsequently account_hardirq_exit() will account too much cpu time as hardirq time. The sum of all accounted cpu times is still correct, however some cpu time which was previously accounted as system time is now accounted as hardirq time, plus there is the oddity that last_update_timer goes back in time. Restore previous behavior by extracting cpu time accounting code from account_idle_time_irq() into a new update_timer_idle() function and call it before irq_enter_rcu(). Fixes: 56e62a737028 ("s390: convert to generic entry") [1] Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-02-22Convert remaining multi-line kmalloc_obj/flex GFP_KERNEL usesKees Cook
Conversion performed via this Coccinelle script: // SPDX-License-Identifier: GPL-2.0-only // Options: --include-headers-for-types --all-includes --include-headers --keep-comments virtual patch @gfp depends on patch && !(file in "tools") && !(file in "samples")@ identifier ALLOC = {kmalloc_obj,kmalloc_objs,kmalloc_flex, kzalloc_obj,kzalloc_objs,kzalloc_flex, kvmalloc_obj,kvmalloc_objs,kvmalloc_flex, kvzalloc_obj,kvzalloc_objs,kvzalloc_flex}; @@ ALLOC(... - , GFP_KERNEL ) $ make coccicheck MODE=patch COCCI=gfp.cocci Build and boot tested x86_64 with Fedora 42's GCC and Clang: Linux version 6.19.0+ (user@host) (gcc (GCC) 15.2.1 20260123 (Red Hat 15.2.1-7), GNU ld version 2.44-12.fc42) #1 SMP PREEMPT_DYNAMIC 1970-01-01 Linux version 6.19.0+ (user@host) (clang version 20.1.8 (Fedora 20.1.8-4.fc42), LLD 20.1.8) #1 SMP PREEMPT_DYNAMIC 1970-01-01 Signed-off-by: Kees Cook <kees@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21Convert 'alloc_obj' family to use the new default GFP_KERNEL argumentLinus Torvalds
This was done entirely with mindless brute force, using git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' | xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/' to convert the new alloc_obj() users that had a simple GFP_KERNEL argument to just drop that argument. Note that due to the extreme simplicity of the scripting, any slightly more complex cases spread over multiple lines would not be triggered: they definitely exist, but this covers the vast bulk of the cases, and the resulting diff is also then easier to check automatically. For the same reason the 'flex' versions will be done as a separate conversion. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21treewide: Replace kmalloc with kmalloc_obj for non-scalar typesKees Cook
This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook <kees@kernel.org>
2026-02-20Merge tag 's390-7.0-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 fixes from Heiko Carstens: - Make KEXEC_SIG available again for CONFIG_MODULES=n - The s390 topology code used to call rebuild_sched_domains() before common code scheduling domains were setup. This was silently ignored by common code, but now results in a warning. Address by avoiding the early call - Convert debug area lock from spinlock to raw spinlock to address lockdep warnings - The recent 3490 tape device driver rework resulted in a different device driver name, which is visible via sysfs for user space. This breaks at least one user space application. Change the device driver name back to its old name to fix this * tag 's390-7.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/tape: Fix device driver name s390/debug: Convert debug area lock from a spinlock to a raw spinlock s390/smp: Avoid calling rebuild_sched_domains() early s390/kexec: Make KEXEC_SIG available when CONFIG_MODULES=n
2026-02-18s390/debug: Convert debug area lock from a spinlock to a raw spinlockBenjamin Block
With PREEMPT_RT as potential configuration option, spinlock_t is now considered as a sleeping lock, and thus might cause issues when used in an atomic context. But even with PREEMPT_RT as potential configuration option, raw_spinlock_t remains as a true spinning lock/atomic context. This creates potential issues with the s390 debug/tracing feature. The functions to trace errors are called in various contexts, including under lock of raw_spinlock_t, and thus the used spinlock_t in each debug area is in violation of the locking semantics. Here are two examples involving failing PCI Read accesses that are traced while holding `pci_lock` in `drivers/pci/access.c`: ============================= [ BUG: Invalid wait context ] 6.19.0-devel #18 Not tainted ----------------------------- bash/3833 is trying to lock: 0000027790baee30 (&rc->lock){-.-.}-{3:3}, at: debug_event_common+0xfc/0x300 other info that might help us debug this: context-{5:5} 5 locks held by bash/3833: #0: 0000027efbb29450 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x7c/0xf0 #1: 00000277f0504a90 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x13e/0x260 #2: 00000277beed8c18 (kn->active#339){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x164/0x260 #3: 00000277e9859190 (&dev->mutex){....}-{4:4}, at: pci_dev_lock+0x2e/0x40 #4: 00000383068a7708 (pci_lock){....}-{2:2}, at: pci_bus_read_config_dword+0x4a/0xb0 stack backtrace: CPU: 6 UID: 0 PID: 3833 Comm: bash Kdump: loaded Not tainted 6.19.0-devel #18 PREEMPTLAZY Hardware name: IBM 9175 ME1 701 (LPAR) Call Trace: [<00000383048afec2>] dump_stack_lvl+0xa2/0xe8 [<00000383049ba166>] __lock_acquire+0x816/0x1660 [<00000383049bb1fa>] lock_acquire+0x24a/0x370 [<00000383059e3860>] _raw_spin_lock_irqsave+0x70/0xc0 [<00000383048bbb6c>] debug_event_common+0xfc/0x300 [<0000038304900b0a>] __zpci_load+0x17a/0x1f0 [<00000383048fad88>] pci_read+0x88/0xd0 [<00000383054cbce0>] pci_bus_read_config_dword+0x70/0xb0 [<00000383054d55e4>] pci_dev_wait+0x174/0x290 [<00000383054d5a3e>] __pci_reset_function_locked+0xfe/0x170 [<00000383054d9b30>] pci_reset_function+0xd0/0x100 [<00000383054ee21a>] reset_store+0x5a/0x80 [<0000038304e98758>] kernfs_fop_write_iter+0x1e8/0x260 [<0000038304d995da>] new_sync_write+0x13a/0x180 [<0000038304d9c5d0>] vfs_write+0x200/0x330 [<0000038304d9c88c>] ksys_write+0x7c/0xf0 [<00000383059cfa80>] __do_syscall+0x210/0x500 [<00000383059e4c06>] system_call+0x6e/0x90 INFO: lockdep is turned off. ============================= [ BUG: Invalid wait context ] 6.19.0-devel #3 Not tainted ----------------------------- bash/6861 is trying to lock: 0000009da05c7430 (&rc->lock){-.-.}-{3:3}, at: debug_event_common+0xfc/0x300 other info that might help us debug this: context-{5:5} 5 locks held by bash/6861: #0: 000000acff404450 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x7c/0xf0 #1: 000000acff41c490 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x13e/0x260 #2: 0000009da36937d8 (kn->active#75){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x164/0x260 #3: 0000009dd15250d0 (&zdev->state_lock){+.+.}-{4:4}, at: enable_slot+0x2e/0xc0 #4: 000001a19682f708 (pci_lock){....}-{2:2}, at: pci_bus_read_config_byte+0x42/0xa0 stack backtrace: CPU: 16 UID: 0 PID: 6861 Comm: bash Kdump: loaded Not tainted 6.19.0-devel #3 PREEMPTLAZY Hardware name: IBM 9175 ME1 701 (LPAR) Call Trace: [<000001a194837ec2>] dump_stack_lvl+0xa2/0xe8 [<000001a194942166>] __lock_acquire+0x816/0x1660 [<000001a1949431fa>] lock_acquire+0x24a/0x370 [<000001a19596b810>] _raw_spin_lock_irqsave+0x70/0xc0 [<000001a194843b6c>] debug_event_common+0xfc/0x300 [<000001a194888b0a>] __zpci_load+0x17a/0x1f0 [<000001a194882d88>] pci_read+0x88/0xd0 [<000001a195453b88>] pci_bus_read_config_byte+0x68/0xa0 [<000001a195457bc2>] pci_setup_device+0x62/0xad0 [<000001a195458e70>] pci_scan_single_device+0x90/0xe0 [<000001a19488a0f6>] zpci_bus_scan_device+0x46/0x80 [<000001a19547f958>] enable_slot+0x98/0xc0 [<000001a19547f134>] power_write_file+0xc4/0x110 [<000001a194e20758>] kernfs_fop_write_iter+0x1e8/0x260 [<000001a194d215da>] new_sync_write+0x13a/0x180 [<000001a194d245d0>] vfs_write+0x200/0x330 [<000001a194d2488c>] ksys_write+0x7c/0xf0 [<000001a195957a30>] __do_syscall+0x210/0x500 [<000001a19596cbb6>] system_call+0x6e/0x90 INFO: lockdep is turned off. Since it is desired to keep it possible to create trace records in most situations, including this particular case (failing PCI config space accesses are relevant), convert the used spinlock_t in `struct debug_info` to raw_spinlock_t. The impact is small, as the debug area lock only protects bounded memory access without external dependencies, apart from one function debug_set_size() where kfree() is implicitly called with the lock held. Move debug_info_free() out of this lock, to keep remove this external dependency. Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-02-17s390/smp: Avoid calling rebuild_sched_domains() earlyHeiko Carstens
Since a recent cpuset code change [1] the kernel emits warnings like this: WARNING: kernel/cgroup/cpuset.c:966 at rebuild_sched_domains_locked+0xe0/0x120, CPU#0: kworker/0:0/9 Modules linked in: CPU: 0 UID: 0 PID: 9 Comm: kworker/0:0 Not tainted 6.20.0-20260215.rc0.git3.bb7a3fc2c976.300.fc43.s390x+git #1 PREEMPTLAZY Hardware name: IBM 3931 A01 703 (KVM/Linux) Workqueue: events topology_work_fn Krnl PSW : 0704c00180000000 000002922e7af5c4 (rebuild_sched_domains_locked+0xe4/0x120) ... Call Trace: [<000002922e7af5c4>] rebuild_sched_domains_locked+0xe4/0x120 [<000002922e7af634>] rebuild_sched_domains+0x34/0x50 [<000002922e6ba232>] process_one_work+0x1b2/0x490 [<000002922e6bc4b8>] worker_thread+0x1f8/0x3b0 [<000002922e6c6a98>] kthread+0x148/0x170 [<000002922e645ffc>] __ret_from_fork+0x3c/0x240 [<000002922f51f492>] ret_from_fork+0xa/0x30 Reason for this is that the s390 specific smp initialization code schedules a work which rebuilds scheduling domains way before the scheduler is smp aware. With the mentioned commit the (invalid) rebuild request is not anymore silently discarded but instead leads to warning. Address this by avoiding the early rebuild request. Reported-by: Marc Hartmayer <marc@linux.ibm.com> Tested-by: Marc Hartmayer <marc@linux.ibm.com> Fixes: 6ee43047e8ad ("cpuset: Remove unnecessary checks in rebuild_sched_domains_locked") [1] Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-02-13Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM updates from Paolo Bonzini: "Loongarch: - Add more CPUCFG mask bits - Improve feature detection - Add lazy load support for FPU and binary translation (LBT) register state - Fix return value for memory reads from and writes to in-kernel devices - Add support for detecting preemption from within a guest - Add KVM steal time test case to tools/selftests ARM: - Add support for FEAT_IDST, allowing ID registers that are not implemented to be reported as a normal trap rather than as an UNDEF exception - Add sanitisation of the VTCR_EL2 register, fixing a number of UXN/PXN/XN bugs in the process - Full handling of RESx bits, instead of only RES0, and resulting in SCTLR_EL2 being added to the list of sanitised registers - More pKVM fixes for features that are not supposed to be exposed to guests - Make sure that MTE being disabled on the pKVM host doesn't give it the ability to attack the hypervisor - Allow pKVM's host stage-2 mappings to use the Force Write Back version of the memory attributes by using the "pass-through' encoding - Fix trapping of ICC_DIR_EL1 on GICv5 hosts emulating GICv3 for the guest - Preliminary work for guest GICv5 support - A bunch of debugfs fixes, removing pointless custom iterators stored in guest data structures - A small set of FPSIMD cleanups - Selftest fixes addressing the incorrect alignment of page allocation - Other assorted low-impact fixes and spelling fixes RISC-V: - Fixes for issues discoverd by KVM API fuzzing in kvm_riscv_aia_imsic_has_attr(), kvm_riscv_aia_imsic_rw_attr(), and kvm_riscv_vcpu_aia_imsic_update() - Allow Zalasr, Zilsd and Zclsd extensions for Guest/VM - Transparent huge page support for hypervisor page tables - Adjust the number of available guest irq files based on MMIO register sizes found in the device tree or the ACPI tables - Add RISC-V specific paging modes to KVM selftests - Detect paging mode at runtime for selftests s390: - Performance improvement for vSIE (aka nested virtualization) - Completely new memory management. s390 was a special snowflake that enlisted help from the architecture's page table management to build hypervisor page tables, in particular enabling sharing the last level of page tables. This however was a lot of code (~3K lines) in order to support KVM, and also blocked several features. The biggest advantages is that the page size of userspace is completely independent of the page size used by the guest: userspace can mix normal pages, THPs and hugetlbfs as it sees fit, and in fact transparent hugepages were not possible before. It's also now possible to have nested guests and guests with huge pages running on the same host - Maintainership change for s390 vfio-pci - Small quality of life improvement for protected guests x86: - Add support for giving the guest full ownership of PMU hardware (contexted switched around the fastpath run loop) and allowing direct access to data MSRs and PMCs (restricted by the vPMU model). KVM still intercepts access to control registers, e.g. to enforce event filtering and to prevent the guest from profiling sensitive host state. This is more accurate, since it has no risk of contention and thus dropped events, and also has significantly less overhead. For more information, see the commit message for merge commit bf2c3138ae36 ("Merge tag 'kvm-x86-pmu-6.20' ...") - Disallow changing the virtual CPU model if L2 is active, for all the same reasons KVM disallows change the model after the first KVM_RUN - Fix a bug where KVM would incorrectly reject host accesses to PV MSRs when running with KVM_CAP_ENFORCE_PV_FEATURE_CPUID enabled, even if those were advertised as supported to userspace, - Fix a bug with protected guest state (SEV-ES/SNP and TDX) VMs, where KVM would attempt to read CR3 configuring an async #PF entry - Fail the build if EXPORT_SYMBOL_GPL or EXPORT_SYMBOL is used in KVM (for x86 only) to enforce usage of EXPORT_SYMBOL_FOR_KVM_INTERNAL. Only a few exports that are intended for external usage, and those are allowed explicitly - When checking nested events after a vCPU is unblocked, ignore -EBUSY instead of WARNing. Userspace can sometimes put the vCPU into what should be an impossible state, and spurious exit to userspace on -EBUSY does not really do anything to solve the issue - Also throw in the towel and drop the WARN on INIT/SIPI being blocked when vCPU is in Wait-For-SIPI, which also resulted in playing whack-a-mole with syzkaller stuffing architecturally impossible states into KVM - Add support for new Intel instructions that don't require anything beyond enumerating feature flags to userspace - Grab SRCU when reading PDPTRs in KVM_GET_SREGS2 - Add WARNs to guard against modifying KVM's CPU caps outside of the intended setup flow, as nested VMX in particular is sensitive to unexpected changes in KVM's golden configuration - Add a quirk to allow userspace to opt-in to actually suppress EOI broadcasts when the suppression feature is enabled by the guest (currently limited to split IRQCHIP, i.e. userspace I/O APIC). Sadly, simply fixing KVM to honor Suppress EOI Broadcasts isn't an option as some userspaces have come to rely on KVM's buggy behavior (KVM advertises Supress EOI Broadcast irrespective of whether or not userspace I/O APIC supports Directed EOIs) - Clean up KVM's handling of marking mapped vCPU pages dirty - Drop a pile of *ancient* sanity checks hidden behind in KVM's unused ASSERT() macro, most of which could be trivially triggered by the guest and/or user, and all of which were useless - Fold "struct dest_map" into its sole user, "struct rtc_status", to make it more obvious what the weird parameter is used for, and to allow fropping these RTC shenanigans if CONFIG_KVM_IOAPIC=n - Bury all of ioapic.h, i8254.h and related ioctls (including KVM_CREATE_IRQCHIP) behind CONFIG_KVM_IOAPIC=y - Add a regression test for recent APICv update fixes - Handle "hardware APIC ISR", a.k.a. SVI, updates in kvm_apic_update_apicv() to consolidate the updates, and to co-locate SVI updates with the updates for KVM's own cache of ISR information - Drop a dead function declaration - Minor cleanups x86 (Intel): - Rework KVM's handling of VMCS updates while L2 is active to temporarily switch to vmcs01 instead of deferring the update until the next nested VM-Exit. The deferred updates approach directly contributed to several bugs, was proving to be a maintenance burden due to the difficulty in auditing the correctness of deferred updates, and was polluting "struct nested_vmx" with a growing pile of booleans - Fix an SGX bug where KVM would incorrectly try to handle EPCM page faults, and instead always reflect them into the guest. Since KVM doesn't shadow EPCM entries, EPCM violations cannot be due to KVM interference and can't be resolved by KVM - Fix a bug where KVM would register its posted interrupt wakeup handler even if loading kvm-intel.ko ultimately failed - Disallow access to vmcb12 fields that aren't fully supported, mostly to avoid weirdness and complexity for FRED and other features, where KVM wants enable VMCS shadowing for fields that conditionally exist - Print out the "bad" offsets and values if kvm-intel.ko refuses to load (or refuses to online a CPU) due to a VMCS config mismatch x86 (AMD): - Drop a user-triggerable WARN on nested_svm_load_cr3() failure - Add support for virtualizing ERAPS. Note, correct virtualization of ERAPS relies on an upcoming, publicly announced change in the APM to reduce the set of conditions where hardware (i.e. KVM) *must* flush the RAP - Ignore nSVM intercepts for instructions that are not supported according to L1's virtual CPU model - Add support for expedited writes to the fast MMIO bus, a la VMX's fastpath for EPT Misconfig - Don't set GIF when clearing EFER.SVME, as GIF exists independently of SVM, and allow userspace to restore nested state with GIF=0 - Treat exit_code as an unsigned 64-bit value through all of KVM - Add support for fetching SNP certificates from userspace - Fix a bug where KVM would use vmcb02 instead of vmcb01 when emulating VMLOAD or VMSAVE on behalf of L2 - Misc fixes and cleanups x86 selftests: - Add a regression test for TPR<=>CR8 synchronization and IRQ masking - Overhaul selftest's MMU infrastructure to genericize stage-2 MMU support, and extend x86's infrastructure to support EPT and NPT (for L2 guests) - Extend several nested VMX tests to also cover nested SVM - Add a selftest for nested VMLOAD/VMSAVE - Rework the nested dirty log test, originally added as a regression test for PML where KVM logged L2 GPAs instead of L1 GPAs, to improve test coverage and to hopefully make the test easier to understand and maintain guest_memfd: - Remove kvm_gmem_populate()'s preparation tracking and half-baked hugepage handling. SEV/SNP was the only user of the tracking and it can do it via the RMP - Retroactively document and enforce (for SNP) that KVM_SEV_SNP_LAUNCH_UPDATE and KVM_TDX_INIT_MEM_REGION require the source page to be 4KiB aligned, to avoid non-trivial complexity for something that no known VMM seems to be doing and to avoid an API special case for in-place conversion, which simply can't support unaligned sources - When populating guest_memfd memory, GUP the source page in common code and pass the refcounted page to the vendor callback, instead of letting vendor code do the heavy lifting. Doing so avoids a looming deadlock bug with in-place due an AB-BA conflict betwee mmap_lock and guest_memfd's filemap invalidate lock Generic: - Fix a bug where KVM would ignore the vCPU's selected address space when creating a vCPU-specific mapping of guest memory. Actually this bug could not be hit even on x86, the only architecture with multiple address spaces, but it's a bug nevertheless" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (267 commits) KVM: s390: Increase permitted SE header size to 1 MiB MAINTAINERS: Replace backup for s390 vfio-pci KVM: s390: vsie: Fix race in acquire_gmap_shadow() KVM: s390: vsie: Fix race in walk_guest_tables() KVM: s390: Use guest address to mark guest page dirty irqchip/riscv-imsic: Adjust the number of available guest irq files RISC-V: KVM: Transparent huge page support RISC-V: KVM: selftests: Add Zalasr extensions to get-reg-list test RISC-V: KVM: Allow Zalasr extensions for Guest/VM KVM: riscv: selftests: Add riscv vm satp modes KVM: riscv: selftests: add Zilsd and Zclsd extension to get-reg-list test riscv: KVM: allow Zilsd and Zclsd extensions for Guest/VM RISC-V: KVM: Skip IMSIC update if vCPU IMSIC state is not initialized RISC-V: KVM: Fix null pointer dereference in kvm_riscv_aia_imsic_rw_attr() RISC-V: KVM: Fix null pointer dereference in kvm_riscv_aia_imsic_has_attr() RISC-V: KVM: Remove unnecessary 'ret' assignment KVM: s390: Add explicit padding to struct kvm_s390_keyop KVM: LoongArch: selftests: Add steal time test case LoongArch: KVM: Add paravirt vcpu_is_preempted() support in guest side LoongArch: KVM: Add paravirt preempt feature in hypervisor side ...
2026-02-12Merge tag 'mm-nonmm-stable-2026-02-12-10-48' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-MM updates from Andrew Morton: - "ocfs2: give ocfs2 the ability to reclaim suballocator free bg" saves disk space by teaching ocfs2 to reclaim suballocator block group space (Heming Zhao) - "Add ARRAY_END(), and use it to fix off-by-one bugs" adds the ARRAY_END() macro and uses it in various places (Alejandro Colomar) - "vmcoreinfo: support VMCOREINFO_BYTES larger than PAGE_SIZE" makes the vmcore code future-safe, if VMCOREINFO_BYTES ever exceeds the page size (Pnina Feder) - "kallsyms: Prevent invalid access when showing module buildid" cleans up kallsyms code related to module buildid and fixes an invalid access crash when printing backtraces (Petr Mladek) - "Address page fault in ima_restore_measurement_list()" fixes a kexec-related crash that can occur when booting the second-stage kernel on x86 (Harshit Mogalapalli) - "kho: ABI headers and Documentation updates" updates the kexec handover ABI documentation (Mike Rapoport) - "Align atomic storage" adds the __aligned attribute to atomic_t and atomic64_t definitions to get natural alignment of both types on csky, m68k, microblaze, nios2, openrisc and sh (Finn Thain) - "kho: clean up page initialization logic" simplifies the page initialization logic in kho_restore_page() (Pratyush Yadav) - "Unload linux/kernel.h" moves several things out of kernel.h and into more appropriate places (Yury Norov) - "don't abuse task_struct.group_leader" removes the usage of ->group_leader when it is "obviously unnecessary" (Oleg Nesterov) - "list private v2 & luo flb" adds some infrastructure improvements to the live update orchestrator (Pasha Tatashin) * tag 'mm-nonmm-stable-2026-02-12-10-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (107 commits) watchdog/hardlockup: simplify perf event probe and remove per-cpu dependency procfs: fix missing RCU protection when reading real_parent in do_task_stat() watchdog/softlockup: fix sample ring index wrap in need_counting_irqs() kcsan, compiler_types: avoid duplicate type issues in BPF Type Format kho: fix doc for kho_restore_pages() tests/liveupdate: add in-kernel liveupdate test liveupdate: luo_flb: introduce File-Lifecycle-Bound global state liveupdate: luo_file: Use private list list: add kunit test for private list primitives list: add primitives for private list manipulations delayacct: fix uapi timespec64 definition panic: add panic_force_cpu= parameter to redirect panic to a specific CPU netclassid: use thread_group_leader(p) in update_classid_task() RDMA/umem: don't abuse current->group_leader drm/pan*: don't abuse current->group_leader drm/amd: kill the outdated "Only the pthreads threading model is supported" checks drm/amdgpu: don't abuse current->group_leader android/binder: use same_thread_group(proc->tsk, current) in binder_mmap() android/binder: don't abuse current->group_leader kho: skip memoryless NUMA nodes when reserving scratch areas ...
2026-02-12Merge tag 'mm-stable-2026-02-11-19-22' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - "powerpc/64s: do not re-activate batched TLB flush" makes arch_{enter|leave}_lazy_mmu_mode() nest properly (Alexander Gordeev) It adds a generic enter/leave layer and switches architectures to use it. Various hacks were removed in the process. - "zram: introduce compressed data writeback" implements data compression for zram writeback (Richard Chang and Sergey Senozhatsky) - "mm: folio_zero_user: clear page ranges" adds clearing of contiguous page ranges for hugepages. Large improvements during demand faulting are demonstrated (David Hildenbrand) - "memcg cleanups" tidies up some memcg code (Chen Ridong) - "mm/damon: introduce {,max_}nr_snapshots and tracepoint for damos stats" improves DAMOS stat's provided information, deterministic control, and readability (SeongJae Park) - "selftests/mm: hugetlb cgroup charging: robustness fixes" fixes a few issues in the hugetlb cgroup charging selftests (Li Wang) - "Fix va_high_addr_switch.sh test failure - again" addresses several issues in the va_high_addr_switch test (Chunyu Hu) - "mm/damon/tests/core-kunit: extend existing test scenarios" improves the KUnit test coverage for DAMON (Shu Anzai) - "mm/khugepaged: fix dirty page handling for MADV_COLLAPSE" fixes a glitch in khugepaged which was causing madvise(MADV_COLLAPSE) to transiently return -EAGAIN (Shivank Garg) - "arch, mm: consolidate hugetlb early reservation" reworks and consolidates a pile of straggly code related to reservation of hugetlb memory from bootmem and creation of CMA areas for hugetlb (Mike Rapoport) - "mm: clean up anon_vma implementation" cleans up the anon_vma implementation in various ways (Lorenzo Stoakes) - "tweaks for __alloc_pages_slowpath()" does a little streamlining of the page allocator's slowpath code (Vlastimil Babka) - "memcg: separate private and public ID namespaces" cleans up the memcg ID code and prevents the internal-only private IDs from being exposed to userspace (Shakeel Butt) - "mm: hugetlb: allocate frozen gigantic folio" cleans up the allocation of frozen folios and avoids some atomic refcount operations (Kefeng Wang) - "mm/damon: advance DAMOS-based LRU sorting" improves DAMOS's movement of memory betewwn the active and inactive LRUs and adds auto-tuning of the ratio-based quotas and of monitoring intervals (SeongJae Park) - "Support page table check on PowerPC" makes CONFIG_PAGE_TABLE_CHECK_ENFORCED work on powerpc (Andrew Donnellan) - "nodemask: align nodes_and{,not} with underlying bitmap ops" makes nodes_and() and nodes_andnot() propagate the return values from the underlying bit operations, enabling some cleanup in calling code (Yury Norov) - "mm/damon: hide kdamond and kdamond_lock from API callers" cleans up some DAMON internal interfaces (SeongJae Park) - "mm/khugepaged: cleanups and scan limit fix" does some cleanup work in khupaged and fixes a scan limit accounting issue (Shivank Garg) - "mm: balloon infrastructure cleanups" goes to town on the balloon infrastructure and its page migration function. Mainly cleanups, also some locking simplification (David Hildenbrand) - "mm/vmscan: add tracepoint and reason for kswapd_failures reset" adds additional tracepoints to the page reclaim code (Jiayuan Chen) - "Replace wq users and add WQ_PERCPU to alloc_workqueue() users" is part of Marco's kernel-wide migration from the legacy workqueue APIs over to the preferred unbound workqueues (Marco Crivellari) - "Various mm kselftests improvements/fixes" provides various unrelated improvements/fixes for the mm kselftests (Kevin Brodsky) - "mm: accelerate gigantic folio allocation" greatly speeds up gigantic folio allocation, mainly by avoiding unnecessary work in pfn_range_valid_contig() (Kefeng Wang) - "selftests/damon: improve leak detection and wss estimation reliability" improves the reliability of two of the DAMON selftests (SeongJae Park) - "mm/damon: cleanup kdamond, damon_call(), damos filter and DAMON_MIN_REGION" does some cleanup work in the core DAMON code (SeongJae Park) - "Docs/mm/damon: update intro, modules, maintainer profile, and misc" performs maintenance work on the DAMON documentation (SeongJae Park) - "mm: add and use vma_assert_stabilised() helper" refactors and cleans up the core VMA code. The main aim here is to be able to use the mmap write lock's lockdep state to perform various assertions regarding the locking which the VMA code requires (Lorenzo Stoakes) - "mm, swap: swap table phase II: unify swapin use" removes some old swap code (swap cache bypassing and swap synchronization) which wasn't working very well. Various other cleanups and simplifications were made. The end result is a 20% speedup in one benchmark (Kairui Song) - "enable PT_RECLAIM on more 64-bit architectures" makes PT_RECLAIM available on 64-bit alpha, loongarch, mips, parisc, and um. Various cleanups were performed along the way (Qi Zheng) * tag 'mm-stable-2026-02-11-19-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (325 commits) mm/memory: handle non-split locks correctly in zap_empty_pte_table() mm: move pte table reclaim code to memory.c mm: make PT_RECLAIM depends on MMU_GATHER_RCU_TABLE_FREE mm: convert __HAVE_ARCH_TLB_REMOVE_TABLE to CONFIG_HAVE_ARCH_TLB_REMOVE_TABLE config um: mm: enable MMU_GATHER_RCU_TABLE_FREE parisc: mm: enable MMU_GATHER_RCU_TABLE_FREE mips: mm: enable MMU_GATHER_RCU_TABLE_FREE LoongArch: mm: enable MMU_GATHER_RCU_TABLE_FREE alpha: mm: enable MMU_GATHER_RCU_TABLE_FREE mm: change mm/pt_reclaim.c to use asm/tlb.h instead of asm-generic/tlb.h mm/damon/stat: remove __read_mostly from memory_idle_ms_percentiles zsmalloc: make common caches global mm: add SPDX id lines to some mm source files mm/zswap: use %pe to print error pointers mm/vmscan: use %pe to print error pointers mm/readahead: fix typo in comment mm: khugepaged: fix NR_FILE_PAGES and NR_SHMEM in collapse_file() mm: refactor vma_map_pages to use vm_insert_pages mm/damon: unify address range representation with damon_addr_range mm/cma: replace snprintf with strscpy in cma_new_area ...
2026-02-11Merge tag 'kvm-s390-next-7.0-1' of ↵Paolo Bonzini
https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD - gmap rewrite: completely new memory management for kvm/s390 - vSIE improvement - maintainership change for s390 vfio-pci - small quality of life improvement for protected guests
2026-02-10Merge tag 'timers-vdso-2026-02-09' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull VDSO updates from Thomas Gleixner: - Provide the missing 64-bit variant of clock_getres() This allows the extension of CONFIG_COMPAT_32BIT_TIME to the vDSO and finally the removal of 32-bit time types from the kernel and UAPI. - Remove the useless and broken getcpu_cache from the VDSO The intention was to provide a trivial way to retrieve the CPU number from the VDSO, but as the VDSO data is per process there is no way to make it work. - Switch get/put_unaligned() from packed struct to memcpy() The packed struct violates strict aliasing rules which requires to pass -fno-strict-aliasing to the compiler. As this are scalar values __builtin_memcpy() turns them into simple loads and stores - Use __typeof_unqual__() for __unqual_scalar_typeof() The get/put_unaligned() changes triggered a new sparse warning when __beNN types are used with get/put_unaligned() as sparse builds add a special 'bitwise' attribute to them which prevents sparse to evaluate the Generic in __unqual_scalar_typeof(). Newer sparse versions support __typeof_unqual__() which avoids the problem, but requires a recent sparse install. So this adds a sanity check to sparse builds, which validates that sparse is available and capable of handling it. - Force inline __cvdso_clock_getres_common() Compilers sometimes un-inline agressively, which results in function call overhead and problems with automatic stack variable initialization. Interestingly enough the force inlining results in smaller code than the un-inlined variant produced by GCC when optimizing for size. * tag 'timers-vdso-2026-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: vdso/gettimeofday: Force inlining of __cvdso_clock_getres_common() x86/percpu: Make CONFIG_USE_X86_SEG_SUPPORT work with sparse compiler: Use __typeof_unqual__() for __unqual_scalar_typeof() powerpc/vdso: Provide clock_getres_time64() tools headers: Remove unneeded ignoring of warnings in unaligned.h tools headers: Update the linux/unaligned.h copy with the kernel sources vdso: Switch get/put_unaligned() from packed struct to memcpy() parisc: Inline a type punning version of get_unaligned_le32() vdso: Remove struct getcpu_cache MIPS: vdso: Provide getres_time64() for 32-bit ABIs arm64: vdso32: Provide clock_getres_time64() ARM: VDSO: Provide clock_getres_time64() ARM: VDSO: Patch out __vdso_clock_getres() if unavailable x86/vdso: Provide clock_getres_time64() for x86-32 selftests: vDSO: vdso_test_abi: Add test for clock_getres_time64() selftests: vDSO: vdso_test_abi: Use UAPI system call numbers selftests: vDSO: vdso_config: Add configurations for clock_getres_time64() vdso: Add prototype for __vdso_clock_getres_time64()
2026-02-10Merge tag 'sched-core-2026-02-09' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "Scheduler Kconfig space updates: - Further consolidate configurable preemption modes (Peter Zijlstra) Reduce the number of architectures that are allowed to offer PREEMPT_NONE and PREEMPT_VOLUNTARY, reducing the number of preemption models from four to just two: 'full' and 'lazy' on up-to-date architectures (arm64, loongarch, powerpc, riscv, s390, x86). None and voluntary are only available as legacy features on platforms that don't implement lazy preemption yet, or which don't even support preemption. The goal is to eventually remove cond_resched() and voluntary preemption altogether. RSEQ based 'scheduler time slice extension' support (Thomas Gleixner and Peter Zijlstra): This allows a thread to request a time slice extension when it enters a critical section to avoid contention on a resource when the thread is scheduled out inside of the critical section. - Add fields and constants for time slice extension - Provide static branch for time slice extensions - Add statistics for time slice extensions - Add prctl() to enable time slice extensions - Implement sys_rseq_slice_yield() - Implement syscall entry work for time slice extensions - Implement time slice extension enforcement timer - Reset slice extension when scheduled - Implement rseq_grant_slice_extension() - entry: Hook up rseq time slice extension - selftests: Implement time slice extension test - Allow registering RSEQ with slice extension - Move slice_ext_nsec to debugfs - Lower default slice extension - selftests/rseq: Add rseq slice histogram script Scheduler performance/scalability improvements: - Update rq->avg_idle when a task is moved to an idle CPU, which improves the scalability of various workloads (Shubhang Kaushik) - Reorder fields in 'struct rq' for better caching (Blake Jones) - Fair scheduler SMP NOHZ balancing code speedups (Shrikanth Hegde): - Move checking for nohz cpus after time check - Change likelyhood of nohz.nr_cpus - Remove nohz.nr_cpus and use weight of cpumask instead - Avoid false sharing for sched_clock_irqtime (Wangyang Guo) - Cleanups (Yury Norov): - Drop useless cpumask_empty() in find_energy_efficient_cpu() - Simplify task_numa_find_cpu() - Use cpumask_weight_and() in sched_balance_find_dst_group() DL scheduler updates: - Add a deadline server for sched_ext tasks (by Andrea Righi and Joel Fernandes, with fixes by Peter Zijlstra) RT scheduler updates: - Skip currently executing CPU in rto_next_cpu() (Chen Jinghuang) Entry code updates and performance improvements (Jinjie Ruan) This is part of the scheduler tree in this cycle due to inter- dependencies with the RSEQ based time slice extension work: - Remove unused syscall argument from syscall_trace_enter() - Rework syscall_exit_to_user_mode_work() for architecture reuse - Add arch_ptrace_report_syscall_entry/exit() - Inline syscall_exit_work() and syscall_trace_enter() Scheduler core updates (Peter Zijlstra): - Rework sched_class::wakeup_preempt() and rq_modified_*() - Avoid rq->lock bouncing in sched_balance_newidle() - Rename rcu_dereference_check_sched_domain() => rcu_dereference_sched_domain() - <linux/compiler_types.h>: Add the __signed_scalar_typeof() helper Fair scheduler updates/refactoring (Peter Zijlstra and Ingo Molnar): - Fold the sched_avg update - Change rcu_dereference_check_sched_domain() to rcu-sched - Switch to rcu_dereference_all() - Remove superfluous rcu_read_lock() - Limit hrtick work - Join two #ifdef CONFIG_FAIR_GROUP_SCHED blocks - Clean up comments in 'struct cfs_rq' - Separate se->vlag from se->vprot - Rename cfs_rq::avg_load to cfs_rq::sum_weight - Rename cfs_rq::avg_vruntime to ::sum_w_vruntime & helper functions - Introduce and use the vruntime_cmp() and vruntime_op() wrappers for wrapped-signed aritmetics - Sort out 'blocked_load*' namespace noise Scheduler debugging code updates: - Export hidden tracepoints to modules (Gabriele Monaco) - Convert copy_from_user() + kstrtouint() to kstrtouint_from_user() (Fushuai Wang) - Add assertions to QUEUE_CLASS (Peter Zijlstra) - hrtimer: Fix tracing oddity (Thomas Gleixner) Misc fixes and cleanups: - Re-evaluate scheduling when migrating queued tasks out of throttled cgroups (Zicheng Qu) - Remove task_struct->faults_disabled_mapping (Christoph Hellwig) - Fix math notation errors in avg_vruntime comment (Zhan Xusheng) - sched/cpufreq: Use %pe format for PTR_ERR() printing (zenghongling)" * tag 'sched-core-2026-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (64 commits) sched: Re-evaluate scheduling when migrating queued tasks out of throttled cgroups sched/cpufreq: Use %pe format for PTR_ERR() printing sched/rt: Skip currently executing CPU in rto_next_cpu() sched/clock: Avoid false sharing for sched_clock_irqtime selftests/sched_ext: Add test for DL server total_bw consistency selftests/sched_ext: Add test for sched_ext dl_server sched/debug: Fix dl_server (re)start conditions sched/debug: Add support to change sched_ext server params sched_ext: Add a DL server for sched_ext tasks sched/debug: Stop and start server based on if it was active sched/debug: Fix updating of ppos on server write ops sched/deadline: Clear the defer params entry: Inline syscall_exit_work() and syscall_trace_enter() entry: Add arch_ptrace_report_syscall_entry/exit() entry: Rework syscall_exit_to_user_mode_work() for architecture reuse entry: Remove unused syscall argument from syscall_trace_enter() sched: remove task_struct->faults_disabled_mapping sched: Update rq->avg_idle when a task is moved to an idle CPU selftests/rseq: Add rseq slice histogram script hrtimer: Fix trace oddity ...
2026-02-09Merge tag 's390-7.0-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Heiko Carstens: - Drop support for outdated 3590/3592 and 3480 tape devices, and limit support to virtualized 3490E types devices - Implement exception based WARN() and WARN_ONCE() similar to x86 - Slightly optimize preempt primitives like __preempt_count_add() and __preempt_count_dec_and_test() - A couple of small fixes and improvements * tag 's390-7.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (35 commits) s390/tape: Consolidate tape config options and modules s390/cio: Fix device lifecycle handling in css_alloc_subchannel() s390/tape: Rename tape_34xx.c to tape_3490.c s390/tape: Cleanup sense data analysis and error handling s390/tape: Remove 3480 tape device type s390/tape: Remove unused command definitions s390/tape: Remove special block id handling s390/tape: Remove tape load display support s390/tape: Remove support for 3590/3592 models s390/kexec: Emit an error message when cmdline is too long s390/configs: Enable BLK_DEV_NULL_BLK as module s390: Document s390 stackprotector support s390/perf: Disable register readout on sampling events s390/Kconfig: Define non-zero ILLEGAL_POINTER_VALUE s390/bug: Prevent tail-call optimization s390/bug: Skip __WARN_trap() in call traces s390/bug: Implement WARN_ONCE() s390/bug: Implement __WARN_printf() s390/traps: Copy monitor code to pt_regs s390/bug: Introduce and use monitor code macro ...
2026-02-04KVM: s390: Switch to new gmapClaudio Imbrenda
Switch KVM/s390 to use the new gmap code. Remove includes to <gmap.h> and include "gmap.h" instead; fix all the existing users of the old gmap functions to use the new ones instead. Fix guest storage key access functions to work with the new gmap. Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>