kernel/linux.git/arch/x86/include/asm, branch v6.18.33

x86/vdso: Clean up remnants of VDSO32_NOTE_MASK

2026-05-23T11:06:25+00:00

[ Upstream commit 6517f293b2c6774d21b6e7e26a55fae60c6ec4cf ] VDSO32_NOTE_MASK is not used or provided anymore, remove it. Fixes: a13f2ef168cb ("x86/xen: remove 32-bit Xen PV guest support") Signed-off-by: Thomas Weißschuh Signed-off-by: Ingo Molnar Cc: H. Peter Anvin Cc: Boris Ostrovsky Cc: Juergen Gross Link: https://patch.msgid.link/20260330-vdso-x86-vdso32_note_mask-v1-1-2f5c473327bf@linutronix.de Signed-off-by: Sasha Levin

x86/tdx: Fix the typo in TDX_ATTR_MIGRTABLE

2026-05-23T11:06:25+00:00

[ Upstream commit 3aecb2e7b948400354399b26f3f1653bd2c1bae0 ] The TD scoped TDCS attributes are defined by bit positions. In the guest side of the TDX code, the 'tdx_attributes' string array holds pretty print names for these attributes, which are generated via macros and defines. Today these pretty print names are only used to print the attribute names to dmesg. Unfortunately there is a typo in the define for the migratable bit. Change the defines TDX_ATTR_MIGRTABLE* to TDX_ATTR_MIGRATABLE*. Update the sole user, the tdx_attributes array, to use the fixed name. Since these defines control the string printed to dmesg, the change is user visible. But the risk of breakage is almost zero since it is not exposed in any interface expected to be consumed programmatically. Fixes: 564ea84c8c14 ("x86/tdx: Dump attributes and TD_CTLS on boot") Signed-off-by: Xiaoyao Li Signed-off-by: Dave Hansen Reviewed-by: Kirill A. Shutemov Reviewed-by: Kai Huang Acked-by: Sean Christopherson Link: https://patch.msgid.link/20260303030335.766779-2-xiaoyao.li@intel.com Signed-off-by: Sasha Levin

x86/CPU/AMD: Prevent improper isolation of shared resources in Zen2's op cache

2026-05-14T13:30:26+00:00

commit c21b90f77687075115d989e53a8ec5e2bb427ab1 upstream. Make sure resources are not improperly shared in the op cache and cause instruction corruption this way. Signed-off-by: Prathyushi Nangia Co-developed-by: Borislav Petkov (AMD) Signed-off-by: Borislav Petkov (AMD) Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

x86/efi: Restore IRQ state in EFI page fault handler

2026-05-14T13:30:13+00:00

commit 2c340aab5485ebe9e33c01437dd4815ef33c8df5 upstream. The kernel's softirq API does not permit re-enabling softirqs while IRQs are disabled. The reason for this is that local_bh_enable() will not only re-enable delivery of softirqs over the back of IRQs, it will also handle any pending softirqs immediately, regardless of whether IRQs are enabled at that point. For this reason, commit d02198550423 ("x86/fpu: Improve crypto performance by making kernel-mode FPU reliably usable in softirqs") disables softirqs only when IRQs are enabled, as it is not permitted otherwise, but also unnecessary, given that asynchronous softirq delivery never happens to begin with while IRQs are disabled. However, this does mean that entering a kernel mode FPU section with IRQs enabled and leaving it with IRQs disabled leads to problems, as identified by Sashiko [0]: the EFI page fault handler is called from page_fault_oops() with IRQs disabled, and thus ends the kernel mode FPU section with IRQs disabled as well, regardless of whether IRQs were enabled when it was started. This may result in schedule() being called with a non-zero preempt_count, causing a BUG(). So take care to re-enable IRQs when handling any EFI page faults if they were taken with IRQs enabled. [0] https://sashiko.dev/#/patchset/20260430074107.27051-1-ivan.hu%40canonical.com Cc: Eric Biggers Cc: Ivan Hu Cc: x86@kernel.org Cc: Fixes: d02198550423 ("x86/fpu: Improve crypto performance by making kernel-mode FPU reliably usable in softirqs") Reviewed-by: Eric Biggers Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman

x86-64/arm64/powerpc: clean up and rename __copy_from_user_flushcache

2026-04-22T11:22:31+00:00

commit 809b997a5ce945ab470f70c187048fe4f5df20bf upstream. This finishes the work on these odd functions that were only implemented by a handful of architectures. The 'flushcache' function was only used from the iterator code, and let's make it do the same thing that the nontemporal version does: remove the two underscores and add the user address checking. Yes, yes, the user address checking is also done at iovec import time, but we have long since walked away from the old double-underscore thing where we try to avoid address checking overhead at access time, and these functions shouldn't be so special and old-fashioned. The arm64 version already did the address check, in fact, so there it's just a matter of renaming it. For powerpc and x86-64 we now do the proper user access boilerplate. Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

x86: rename and clean up __copy_from_user_inatomic_nocache()

2026-04-22T11:22:31+00:00

commit 5de7bcaadf160c1716b20a263cf8f5b06f658959 upstream. Similarly to the previous commit, this renames the somewhat confusingly named function. But in this case, it was at least less confusing: the __copy_from_user_inatomic_nocache is indeed copying from user memory, and it is indeed ok to be used in an atomic context, so it will not warn about it. But the previous commit also removed the NTB mis-use of the __copy_from_user_inatomic_nocache() function, and as a result every call-site is now _actually_ doing a real user copy. That means that we can now do the proper user pointer verification too. End result: add proper address checking, remove the double underscores, and change the "nocache" to "nontemporal" to more accurately describe what this x86-only function actually does. It might be worth noting that only the target is non-temporal: the actual user accesses are normal memory accesses. Also worth noting is that non-x86 targets (and on older 32-bit x86 CPU's before XMM2 in the Pentium III) we end up just falling back on a regular user copy, so nothing can actually depend on the non-temporal semantics, but that has always been true. Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

x86-64: rename misleadingly named '__copy_user_nocache()' function

2026-04-22T11:22:31+00:00

commit d187a86de793f84766ea40b9ade7ac60aabbb4fe upstream. This function was a masterclass in bad naming, for various historical reasons. It claimed to be a non-cached user copy. It is literally _neither_ of those things. It's a specialty memory copy routine that uses non-temporal stores for the destination (but not the source), and that does exception handling for both source and destination accesses. Also note that while it works for unaligned targets, any unaligned parts (whether at beginning or end) will not use non-temporal stores, since only words and quadwords can be non-temporal on x86. The exception handling means that it _can_ be used for user space accesses, but not on its own - it needs all the normal "start user space access" logic around it. But typically the user space access would be the source, not the non-temporal destination. That was the original intention of this, where the destination was some fragile persistent memory target that needed non-temporal stores in order to catch machine check exceptions synchronously and deal with them gracefully. Thus that non-descriptive name: one use case was to copy from user space into a non-cached kernel buffer. However, the existing users are a mix of that intended use-case, and a couple of random drivers that just did this as a performance tweak. Some of those random drivers then actively misused the user copying version (with STAC/CLAC and all) to do kernel copies without ever even caring about the exception handling, _just_ for the non-temporal destination. Rename it as a first small step to actually make it halfway sane, and change the prototype to be more normal: it doesn't take a user pointer unless the caller has done the proper conversion, and the argument size is the full size_t (it still won't actually copy more than 4GB in one go, but there's also no reason to silently truncate the size argument in the caller). Finally, use this now sanely named function in the NTB code, which mis-used a user copy version (with STAC/CLAC and all) of this interface despite it not actually being a user copy at all. Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

x86/CPU: Fix FPDSS on Zen1

2026-04-18T08:45:02+00:00

commit e55d98e7756135f32150b9b8f75d580d0d4b2dd3 upstream. Zen1's hardware divider can leave, under certain circumstances, partial results from previous operations. Those results can be leaked by another, attacker thread. Fix that with a chicken bit. Signed-off-by: Borislav Petkov (AMD) Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

unwind_user/x86: Fix arch=um build

2026-04-02T11:23:29+00:00

commit aa7387e79a5cff0585cd1b9091944142a06872b6 upstream. Add CONFIG_HAVE_UNWIND_USER_FP guards to make sure this code doesn't break arch=um builds. Reported-by: kernel test robot Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Closes: https://lore.kernel.org/oe-kbuild-all/202510291919.FFGyU7nq-lkp@intel.com/ Signed-off-by: Greg Kroah-Hartman

KVM: x86: Introduce KVM_X86_QUIRK_VMCS12_ALLOW_FREEZE_IN_SMM

2026-03-19T15:08:24+00:00

commit e2ffe85b6d2bb7780174b87aa4468a39be17eb81 upstream. Add KVM_X86_QUIRK_VMCS12_ALLOW_FREEZE_IN_SMM to allow L1 to set FREEZE_IN_SMM in vmcs12's GUEST_IA32_DEBUGCTL field, as permitted prior to commit 6b1dd26544d0 ("KVM: VMX: Preserve host's DEBUGCTLMSR_FREEZE_IN_SMM while running the guest"). Enable the quirk by default for backwards compatibility (like all quirks); userspace can disable it via KVM_CAP_DISABLE_QUIRKS2 for consistency with the constraints on WRMSR(IA32_DEBUGCTL). Note that the quirk only bypasses the consistency check. The vmcs02 bit is still owned by the host, and PMCs are not frozen during virtualized SMM. In particular, if a host administrator decides that PMCs should not be frozen during physical SMM, then L1 has no say in the matter. Fixes: 095686e6fcb4 ("KVM: nVMX: Check vmcs12->guest_ia32_debugctl on nested VM-Enter") Cc: stable@vger.kernel.org Signed-off-by: Jim Mattson Link: https://patch.msgid.link/20260205231537.1278753-1-jmattson@google.com [sean: tag for stable@, clean-up and fix goofs in the comment and docs] Signed-off-by: Sean Christopherson [Rename quirk. - Paolo] Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman