linux/arch, branch for-next

Merge tag 'x86_urgent_for_v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2025-01-19T17:33:40Z

Pull x86 fixes from Borislav Petkov: - Mark serialize() noinstr so that it can be used from instrumentation- free code - Make sure FRED's RSP0 MSR is synchronized with its corresponding per-CPU value in order to avoid double faults in hotplug scenarios - Disable EXECMEM_ROX on x86 for now because it didn't receive proper x86 maintainers review, went in and broke a bunch of things * tag 'x86_urgent_for_v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/asm: Make serialize() always_inline x86/fred: Fix the FRED RSP0 MSR out of sync with its per-CPU cache x86: Disable EXECMEM_ROX support

x86/asm: Make serialize() always_inline

2025-01-16T15:51:17Z

In order to allow serialize() to be used from noinstr code, make it __always_inline. Fixes: 0ef8047b737d ("x86/static-call: provide a way to do very early static-call updates") Closes: https://lore.kernel.org/oe-kbuild-all/202412181756.aJvzih2K-lkp@intel.com/ Reported-by: kernel test robot Signed-off-by: Juergen Gross Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/r/20241218100918.22167-1-jgross@suse.com

x86/fred: Fix the FRED RSP0 MSR out of sync with its per-CPU cache

2025-01-14T22:16:36Z

The FRED RSP0 MSR is only used for delivering events when running userspace. Linux leverages this property to reduce expensive MSR writes and optimize context switches. The kernel only writes the MSR when about to run userspace *and* when the MSR has actually changed since the last time userspace ran. This optimization is implemented by maintaining a per-CPU cache of FRED RSP0 and then checking that against the value for the top of current task stack before running userspace. However cpu_init_fred_exceptions() writes the MSR without updating the per-CPU cache. This means that the kernel might return to userspace with MSR_IA32_FRED_RSP0==0 when it needed to point to the top of current task stack. This would induce a double fault (#DF), which is bad. A context switch after cpu_init_fred_exceptions() can paper over the issue since it updates the cached value. That evidently happens most of the time explaining how this bug got through. Fix the bug through resynchronizing the FRED RSP0 MSR with its per-CPU cache in cpu_init_fred_exceptions(). Fixes: fe85ee391966 ("x86/entry: Set FRED RSP0 on return to userspace instead of context switch") Signed-off-by: Xin Li (Intel) Signed-off-by: Dave Hansen Acked-by: Dave Hansen Cc:stable@vger.kernel.org Link: https://lore.kernel.org/all/20250110174639.1250829-1-xin%40zytor.com

Merge tag 'mm-hotfixes-stable-2025-01-13-00-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2025-01-13T17:03:18Z

Pull misc fixes from Andrew Morton: "18 hotfixes. 11 are cc:stable. 13 are MM and 5 are non-MM. All patches are singletons - please see the relevant changelogs for details" * tag 'mm-hotfixes-stable-2025-01-13-00-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: fs/proc: fix softlockup in __read_vmcore (part 2) mm: fix assertion in folio_end_read() mm: vmscan : pgdemote vmstat is not getting updated when MGLRU is enabled. vmstat: disable vmstat_work on vmstat_cpu_down_prep() zram: fix potential UAF of zram table selftests/mm: set allocated memory to non-zero content in cow test mm: clear uffd-wp PTE/PMD state on mremap() module: fix writing of livepatch relocations in ROX text mm: zswap: properly synchronize freeing resources during CPU hotunplug Revert "mm: zswap: fix race between [de]compression and CPU hotunplug" hugetlb: fix NULL pointer dereference in trace_hugetlbfs_alloc_inode mm: fix div by zero in bdi_ratio_from_pages x86/execmem: fix ROX cache usage in Xen PV guests filemap: avoid truncating 64-bit offset to 32 bits tools: fix atomic_set() definition to set the value correctly mm/mempolicy: count MPOL_WEIGHTED_INTERLEAVE to "interleave_hit" scripts/decode_stacktrace.sh: fix decoding of lines with an additional info mm/kmemleak: fix percpu memory leak detection failure

x86: Disable EXECMEM_ROX support

2025-01-13T11:42:51Z

The whole module_writable_address() nonsense made a giant mess of alternative.c, not to mention it still contains bugs -- notable some of the CFI variants crash and burn. Mike has been working on patches to clean all this up again, but given the current state of things, this stuff just isn't ready. Disable for now, lets try again next cycle. Fixes: 5185e7f9f3bd ("x86/module: enable ROX caches for module text on 64 bit") Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/r/20250113112934.GA8385@noisy.programming.kicks-ass.net

x86/execmem: fix ROX cache usage in Xen PV guests

2025-01-13T03:03:35Z

The recently introduced ROX cache for modules is assuming large page support in 64-bit mode without testing the related feature bit. This results in breakage when running as a Xen PV guest, as in this mode large pages are not supported. Fix that by testing the X86_FEATURE_PSE capability when deciding whether to enable the ROX cache. Link: https://lkml.kernel.org/r/20250103065631.26459-1-jgross@suse.com Fixes: 2e45474ab14f ("execmem: add support for cache of large ROX pages") Signed-off-by: Juergen Gross Reported-by: Marek Marczykowski-Górecki Tested-by: Marek Marczykowski-Górecki Cc: Luis Chamberlain Cc: Andy Lutomirski Cc: Dave Hansen Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Mike Rapoport (Microsoft) Cc: Peter Zijlstra Cc: Thomas Gleixner Signed-off-by: Andrew Morton

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2025-01-12T20:04:53Z

Pull kvm fixes from Paolo Bonzini: "The largest part here is for KVM/PPC, where a NULL pointer dereference was introduced in the 6.13 merge window and is now fixed. There's some "holiday-induced lateness", as the s390 submaintainer put it, but otherwise things looks fine. s390: - fix a latent bug when the kernel is compiled in debug mode - two small UCONTROL fixes and their selftests arm64: - always check page state in hyp_ack_unshare() - align set_id_regs selftest with the fact that ASIDBITS field is RO - various vPMU fixes for bugs that only affect nested virt PPC e500: - Fix a mostly impossible (but just wrong) case where IRQs were never re-enabled - Observe host permissions instead of mapping readonly host pages as guest-writable. This fixes a NULL-pointer dereference in 6.13 - Replace brittle VMA-based attempts at building huge shadow TLB entries with PTE lookups" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: e500: perform hugepage check after looking up the PFN KVM: e500: map readonly host pages for read KVM: e500: track host-writability of pages KVM: e500: use shadow TLB entry as witness for writability KVM: e500: always restore irqs KVM: s390: selftests: Add has device attr check to uc_attr_mem_limit selftest KVM: s390: selftests: Add ucontrol gis routing test KVM: s390: Reject KVM_SET_GSI_ROUTING on ucontrol VMs KVM: s390: selftests: Add ucontrol flic attr selftests KVM: s390: Reject setting flic pfault attributes on ucontrol VMs KVM: s390: vsie: fix virtual/physical address in unpin_scb() KVM: arm64: Only apply PMCR_EL0.P to the guest range of counters KVM: arm64: nv: Reload PMU events upon MDCR_EL2.HPME change KVM: arm64: Use KVM_REQ_RELOAD_PMU to handle PMCR_EL0.E change KVM: arm64: Add unified helper for reprogramming counters by mask KVM: arm64: Always check the state from hyp_ack_unshare() KVM: arm64: Fix set_id_regs selftest for ASIDBITS becoming unwritable

Merge tag 'x86_urgent_for_v6.13_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2025-01-12T19:55:48Z

Pull x86 fixes from Borislav Petkov: - Check whether shadow stack is active before using the ptrace regset getter - Remove a wrong BUG_ON in the early static call code which breaks Xen PVH when booting as dom0 * tag 'x86_urgent_for_v6.13_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/fpu: Ensure shadow stack is active before "getting" registers x86/static-call: Remove early_boot_irqs_disabled check to fix Xen PVH dom0

Merge tag 'kvm-s390-master-6.13-1' of https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

2025-01-12T11:51:05Z

KVM: s390: three small bugfixes Fix a latent bug when the kernel is compiled in debug mode. Two small UCONTROL fixes and their selftests.

Merge tag 'kvmarm-fixes-6.13-3' of https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

2025-01-12T11:50:39Z

KVM/arm64 changes for 6.13, part #3 - Always check page state in hyp_ack_unshare() - Align set_id_regs selftest with the fact that ASIDBITS field is RO - Various vPMU fixes for bugs that only affect nested virt