summaryrefslogtreecommitdiff
path: root/arch/x86
AgeCommit message (Collapse)Author
2024-07-15Merge tag 'ras_core_for_v6.11_rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RAS updates from Borislav Petkov: - A cleanup and a correction to the error injection driver to inject a MCA_MISC value only when one has actually been supplied by the user * tag 'ras_core_for_v6.11_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mce: Remove unused variable and return value in machine_check_poll() x86/mce/inject: Only write MCA_MISC when a value has been supplied
2024-07-15Merge tag 'timers-core-2024-07-14' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer updates from Thomas Gleixner: "Updates for timers, timekeeping and related functionality: Core: - Make the takeover of a hrtimer based broadcast timer reliable during CPU hot-unplug. The current implementation suffers from a race which can lead to broadcast timer starvation in the worst case. - VDSO related cleanups and simplifications - Small cleanups and enhancements all over the place PTP: - Replace the architecture specific base clock to clocksource, e.g. ART to TSC, conversion function with generic functionality to avoid exposing such internals to drivers and convert all existing drivers over. This also allows to provide functionality which converts the other way round in the core code based on the same parameter set. - Provide a function to convert CLOCK_REALTIME to the base clock to support the upcoming PPS output driver on Intel platforms. Drivers: - A set of Device Tree bindings for new hardware - Cleanups and enhancements all over the place" * tag 'timers-core-2024-07-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (30 commits) clocksource/drivers/realtek: Add timer driver for rtl-otto platforms dt-bindings: timer: Add schema for realtek,otto-timer dt-bindings: timer: Add SOPHGO SG2002 clint dt-bindings: timer: renesas,tmu: Add R-Car Gen2 support dt-bindings: timer: renesas,tmu: Add RZ/G1 support dt-bindings: timer: renesas,tmu: Add R-Mobile APE6 support clocksource/drivers/mips-gic-timer: Correct sched_clock width clocksource/drivers/mips-gic-timer: Refine rating computation clocksource/drivers/sh_cmt: Address race condition for clock events clocksource/driver/arm_global_timer: Remove unnecessary ‘0’ values from err clocksource/drivers/arm_arch_timer: Remove unnecessary ‘0’ values from irq tick/broadcast: Make takeover of broadcast hrtimer reliable tick/sched: Combine WARN_ON_ONCE and print_once x86/vdso: Remove unused include x86/vgtod: Remove unused typedef gtod_long_t x86/vdso: Fix function reference in comment vdso: Add comment about reason for vdso struct ordering vdso/gettimeofday: Clarify comment about open coded function timekeeping: Add missing kernel-doc function comments tick: Remove unnused tick_nohz_get_idle_calls() ...
2024-07-15Merge branch 'word-at-a-time'Linus Torvalds
Merge minor word-at-a-time instruction choice improvements for x86 and arm64. This is the second of four branches that came out of me looking at the code generation for path lookup on arm64. The word-at-a-time infrastructure is used to do string operations in chunks of one word both when copying the pathname from user space (in strncpy_from_user()), and when parsing and hashing the individual path components (in link_path_walk()). In particular, the "find the first zero byte" uses various bit tricks to figure out the end of the string or path component, and get the length without having to do things one byte at a time. Both x86-64 and arm64 had less than optimal code choices for that. The commit message for the arm64 change in particular tries to explain the exact code flow for the zero byte finding for people who care. It's made a bit more complicated by the fact that we support big-endian hardware too, and so we have some extra abstraction layers to allow different models for finding the zero byte, quite apart from the issue of picking specialized instructions. * word-at-a-time: arm64: word-at-a-time: improve byte count calculations for LE x86-64: word-at-a-time: improve byte count calculations
2024-07-15Merge branch 'runtime-constants'Linus Torvalds
Merge runtime constants infrastructure with implementations for x86 and arm64. This is one of four branches that came out of me looking at profiles of my kernel build filesystem load on my 128-core Altra arm64 system, where pathname walking and the user copies (particularly strncpy_from_user() for fetching the pathname from user space) is very hot. This is a very specialized "instruction alternatives" model where the dentry hash pointer and hash count will be constants for the lifetime of the kernel, but the allocation are not static but done early during the kernel boot. In order to avoid the pointer load and dynamic shift, we just rewrite the constants in the instructions in place. We can't use the "generic" alternative instructions infrastructure, because different architectures do it very differently, and it's actually simpler to just have very specific helpers, with a fallback to the generic ("old") model of just using variables for architectures that do not implement the runtime constant patching infrastructure. Link: https://lore.kernel.org/all/CAHk-=widPe38fUNjUOmX11ByDckaeEo9tN4Eiyke9u1SAtu9sA@mail.gmail.com/ * runtime-constants: arm64: add 'runtime constant' support runtime constants: add x86 architecture support runtime constants: add default dummy infrastructure vfs: dcache: move hashlen_hash() from callers into d_hash()
2024-07-13Merge tag 'timers-v6.11-rc1' of ↵Thomas Gleixner
https://git.linaro.org/people/daniel.lezcano/linux into timers/core Pull clocksource/event driver updates from Daniel Lezcano: - Remove unnecessary local variables initialization as they will be initialized in the code path anyway right after on the ARM arch timer and the ARM global timer (Li kunyu) - Fix a race condition in the interrupt leading to a deadlock on the SH CMT driver. Note that this fix was not tested on the platform using this timer but the fix seems reasonable enough to be picked confidently (Niklas Söderlund) - Increase the rating of the gic-timer and use the configured width clocksource register on the MIPS architecture (Jiaxun Yang) - Add the DT bindings for the TMU on the Renesas platforms (Geert Uytterhoeven) - Add the DT bindings for the SOPHGO SG2002 clint on RiscV (Thomas Bonnefille) - Add the rtl-otto timer driver along with the DT bindings for the Realtek platform (Chris Packham) Link: https://lore.kernel.org/all/91cd05de-4c5d-4242-a381-3b8a4fe6a2a2@linaro.org
2024-07-03x86/vdso: Remove unused includeAnna-Maria Behnsen
Including hrtimer.h is not required and is probably a historical leftover. Remove it. Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Link: https://lore.kernel.org/r/20240701-vdso-cleanup-v1-5-36eb64e7ece2@linutronix.de
2024-07-03x86/vgtod: Remove unused typedef gtod_long_tAnna-Maria Behnsen
The typedef gtod_long_t is not used anymore so remove it. The header file contains then only includes dependent on CONFIG_GENERIC_GETTIMEOFDAY to not break ARCH=um. Nevertheless, keep the header file only with those includes to prevent spreading ifdeffery all over the place. Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Link: https://lore.kernel.org/r/20240701-vdso-cleanup-v1-4-36eb64e7ece2@linutronix.de
2024-07-03x86/vdso: Fix function reference in commentAnna-Maria Behnsen
Replace the reference to the non-existent function arch_vdso_cycles_valid() by the proper function arch_vdso_cycles_ok(). Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Link: https://lore.kernel.org/r/20240701-vdso-cleanup-v1-3-36eb64e7ece2@linutronix.de
2024-07-03x86/bhi: Avoid warning in #DB handler due to BHI mitigationAlexandre Chartre
When BHI mitigation is enabled, if SYSENTER is invoked with the TF flag set then entry_SYSENTER_compat() uses CLEAR_BRANCH_HISTORY and calls the clear_bhb_loop() before the TF flag is cleared. This causes the #DB handler (exc_debug_kernel()) to issue a warning because single-step is used outside the entry_SYSENTER_compat() function. To address this issue, entry_SYSENTER_compat() should use CLEAR_BRANCH_HISTORY after making sure the TF flag is cleared. The problem can be reproduced with the following sequence: $ cat sysenter_step.c int main() { asm("pushf; pop %ax; bts $8,%ax; push %ax; popf; sysenter"); } $ gcc -o sysenter_step sysenter_step.c $ ./sysenter_step Segmentation fault (core dumped) The program is expected to crash, and the #DB handler will issue a warning. Kernel log: WARNING: CPU: 27 PID: 7000 at arch/x86/kernel/traps.c:1009 exc_debug_kernel+0xd2/0x160 ... RIP: 0010:exc_debug_kernel+0xd2/0x160 ... Call Trace: <#DB> ? show_regs+0x68/0x80 ? __warn+0x8c/0x140 ? exc_debug_kernel+0xd2/0x160 ? report_bug+0x175/0x1a0 ? handle_bug+0x44/0x90 ? exc_invalid_op+0x1c/0x70 ? asm_exc_invalid_op+0x1f/0x30 ? exc_debug_kernel+0xd2/0x160 exc_debug+0x43/0x50 asm_exc_debug+0x1e/0x40 RIP: 0010:clear_bhb_loop+0x0/0xb0 ... </#DB> <TASK> ? entry_SYSENTER_compat_after_hwframe+0x6e/0x8d </TASK> [ bp: Massage commit message. ] Fixes: 7390db8aea0d ("x86/bhi: Add support for clearing branch history at syscall entry") Reported-by: Suman Maity <suman.m.maity@oracle.com> Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> Reviewed-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org> Link: https://lore.kernel.org/r/20240524070459.3674025-1-alexandre.chartre@oracle.com
2024-06-30x86-32: fix cmpxchg8b_emu build error with clangLinus Torvalds
The kernel test robot reported that clang no longer compiles the 32-bit x86 kernel in some configurations due to commit 95ece48165c1 ("locking/atomic/x86: Rewrite x86_32 arch_atomic64_{,fetch}_{and,or,xor}() functions"). The build fails with arch/x86/include/asm/cmpxchg_32.h:149:9: error: inline assembly requires more registers than available and the reason seems to be that not only does the cmpxchg8b instruction need four fixed registers (EDX:EAX and ECX:EBX), with the emulation fallback the inline asm also wants a fifth fixed register for the address (it uses %esi for that, but that's just a software convention with cmpxchg8b_emu). Avoiding using another pointer input to the asm (and just forcing it to use the "0(%esi)" addressing that we end up requiring for the sw fallback) seems to fix the issue. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202406230912.F6XFIyA6-lkp@intel.com/ Fixes: 95ece48165c1 ("locking/atomic/x86: Rewrite x86_32 arch_atomic64_{,fetch}_{and,or,xor}() functions") Link: https://lore.kernel.org/all/202406230912.F6XFIyA6-lkp@intel.com/ Suggested-by: Uros Bizjak <ubizjak@gmail.com> Reviewed-and-Tested-by: Uros Bizjak <ubizjak@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-06-28Merge tag 'hardening-v6.10-rc6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull hardening fixes from Kees Cook: - Remove invalid tty __counted_by annotation (Nathan Chancellor) - Add missing MODULE_DESCRIPTION()s for KUnit string tests (Jeff Johnson) - Remove non-functional per-arch kstack entropy filtering * tag 'hardening-v6.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: tty: mxser: Remove __counted_by from mxser_board.ports[] randomize_kstack: Remove non-functional per-arch entropy filtering string: kunit: add missing MODULE_DESCRIPTION() macros
2024-06-28x86: stop playing stack games in profile_pc()Linus Torvalds
The 'profile_pc()' function is used for timer-based profiling, which isn't really all that relevant any more to begin with, but it also ends up making assumptions based on the stack layout that aren't necessarily valid. Basically, the code tries to account the time spent in spinlocks to the caller rather than the spinlock, and while I support that as a concept, it's not worth the code complexity or the KASAN warnings when no serious profiling is done using timers anyway these days. And the code really does depend on stack layout that is only true in the simplest of cases. We've lost the comment at some point (I think when the 32-bit and 64-bit code was unified), but it used to say: Assume the lock function has either no stack frame or a copy of eflags from PUSHF. which explains why it just blindly loads a word or two straight off the stack pointer and then takes a minimal look at the values to just check if they might be eflags or the return pc: Eflags always has bits 22 and up cleared unlike kernel addresses but that basic stack layout assumption assumes that there isn't any lock debugging etc going on that would complicate the code and cause a stack frame. It causes KASAN unhappiness reported for years by syzkaller [1] and others [2]. With no real practical reason for this any more, just remove the code. Just for historical interest, here's some background commits relating to this code from 2006: 0cb91a229364 ("i386: Account spinlocks to the caller during profiling for !FP kernels") 31679f38d886 ("Simplify profile_pc on x86-64") and a code unification from 2009: ef4512882dbe ("x86: time_32/64.c unify profile_pc") but the basics of this thing actually goes back to before the git tree. Link: https://syzkaller.appspot.com/bug?extid=84fe685c02cd112a2ac3 [1] Link: https://lore.kernel.org/all/CAK55_s7Xyq=nh97=K=G1sxueOFrJDAvPOJAL4TPTCAYvmxO9_A@mail.gmail.com/ [2] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-06-28randomize_kstack: Remove non-functional per-arch entropy filteringKees Cook
An unintended consequence of commit 9c573cd31343 ("randomize_kstack: Improve entropy diffusion") was that the per-architecture entropy size filtering reduced how many bits were being added to the mix, rather than how many bits were being used during the offsetting. All architectures fell back to the existing default of 0x3FF (10 bits), which will consume at most 1KiB of stack space. It seems that this is working just fine, so let's avoid the confusion and update everything to use the default. The prior intent of the per-architecture limits were: arm64: capped at 0x1FF (9 bits), 5 bits effective powerpc: uncapped (10 bits), 6 or 7 bits effective riscv: uncapped (10 bits), 6 bits effective x86: capped at 0xFF (8 bits), 5 (x86_64) or 6 (ia32) bits effective s390: capped at 0xFF (8 bits), undocumented effective entropy Current discussion has led to just dropping the original per-architecture filters. The additional entropy appears to be safe for arm64, x86, and s390. Quoting Arnd, "There is no point pretending that 15.75KB is somehow safe to use while 15.00KB is not." Co-developed-by: Yuntao Liu <liuyuntao12@huawei.com> Signed-off-by: Yuntao Liu <liuyuntao12@huawei.com> Fixes: 9c573cd31343 ("randomize_kstack: Improve entropy diffusion") Link: https://lore.kernel.org/r/20240617133721.377540-1-liuyuntao12@huawei.com Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> # s390 Link: https://lore.kernel.org/r/20240619214711.work.953-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2024-06-25syscalls: fix compat_sys_io_pgetevents_time64 usageArnd Bergmann
Using sys_io_pgetevents() as the entry point for compat mode tasks works almost correctly, but misses the sign extension for the min_nr and nr arguments. This was addressed on parisc by switching to compat_sys_io_pgetevents_time64() in commit 6431e92fc827 ("parisc: io_pgetevents_time64() needs compat syscall in 32-bit compat mode"), as well as by using more sophisticated system call wrappers on x86 and s390. However, arm64, mips, powerpc, sparc and riscv still have the same bug. Change all of them over to use compat_sys_io_pgetevents_time64() like parisc already does. This was clearly the intention when the function was originally added, but it got hooked up incorrectly in the tables. Cc: stable@vger.kernel.org Fixes: 48166e6ea47d ("y2038: add 64-bit time_t syscalls to all 32-bit architectures") Acked-by: Heiko Carstens <hca@linux.ibm.com> # s390 Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-06-23Merge tag 'x86_urgent_for_v6.10_rc5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Borislav Petkov: - An ARM-relevant fix to not free default RMIDs of a resource control group - A randconfig build fix for the VMware virtual GPU driver * tag 'x86_urgent_for_v6.10_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/resctrl: Don't try to free nonexistent RMIDs drm/vmwgfx: Fix missing HYPERVISOR_GUEST dependency
2024-06-22Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm fixes from Paolo Bonzini: "ARM: - Fix dangling references to a redistributor region if the vgic was prematurely destroyed. - Properly mark FFA buffers as released, ensuring that both parties can make forward progress. x86: - Allow getting/setting MSRs for SEV-ES guests, if they're using the pre-6.9 KVM_SEV_ES_INIT API. - Always sync pending posted interrupts to the IRR prior to IOAPIC route updates, so that EOIs are intercepted properly if the old routing table requested that. Generic: - Avoid __fls(0) - Fix reference leak on hwpoisoned page - Fix a race in kvm_vcpu_on_spin() by ensuring loads and stores are atomic. - Fix bug in __kvm_handle_hva_range() where KVM calls a function pointer that was intended to be a marker only (nothing bad happens but kind of a mine and also technically undefined behavior) - Do not bother accounting allocations that are small and freed before getting back to userspace. Selftests: - Fix compilation for RISC-V. - Fix a "shift too big" goof in the KVM_SEV_INIT2 selftest. - Compute the max mappable gfn for KVM selftests on x86 using GuestMaxPhyAddr from KVM's supported CPUID (if it's available)" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: SEV-ES: Fix svm_get_msr()/svm_set_msr() for KVM_SEV_ES_INIT guests KVM: Discard zero mask with function kvm_dirty_ring_reset virt: guest_memfd: fix reference leak on hwpoisoned page kvm: do not account temporary allocations to kmem MAINTAINERS: Drop Wanpeng Li as a Reviewer for KVM Paravirt support KVM: x86: Always sync PIR to IRR prior to scanning I/O APIC routes KVM: Stop processing *all* memslots when "null" mmu_notifier handler is found KVM: arm64: FFA: Release hyp rx buffer KVM: selftests: Fix RISC-V compilation KVM: arm64: Disassociate vcpus from redistributor region on teardown KVM: Fix a data race on last_boosted_vcpu in kvm_vcpu_on_spin() KVM: selftests: x86: Prioritize getting max_gfn from GuestPhysBits KVM: selftests: Fix shift of 32 bit unsigned int more than 32 bits
2024-06-21KVM: SEV-ES: Fix svm_get_msr()/svm_set_msr() for KVM_SEV_ES_INIT guestsMichael Roth
With commit 27bd5fdc24c0 ("KVM: SEV-ES: Prevent MSR access post VMSA encryption"), older VMMs like QEMU 9.0 and older will fail when booting SEV-ES guests with something like the following error: qemu-system-x86_64: error: failed to get MSR 0x174 qemu-system-x86_64: ../qemu.git/target/i386/kvm/kvm.c:3950: kvm_get_msrs: Assertion `ret == cpu->kvm_msr_buf->nmsrs' failed. This is because older VMMs that might still call svm_get_msr()/svm_set_msr() for SEV-ES guests after guest boot even if those interfaces were essentially just noops because of the vCPU state being encrypted and stored separately in the VMSA. Now those VMMs will get an -EINVAL and generally crash. Newer VMMs that are aware of KVM_SEV_INIT2 however are already aware of the stricter limitations of what vCPU state can be sync'd during guest run-time, so newer QEMU for instance will work both for legacy KVM_SEV_ES_INIT interface as well as KVM_SEV_INIT2. So when using KVM_SEV_INIT2 it's okay to assume userspace can deal with -EINVAL, whereas for legacy KVM_SEV_ES_INIT the kernel might be dealing with either an older VMM and so it needs to assume that returning -EINVAL might break the VMM. Address this by only returning -EINVAL if the guest was started with KVM_SEV_INIT2. Otherwise, just silently return. Cc: Ravi Bangoria <ravi.bangoria@amd.com> Cc: Nikunj A Dadhania <nikunj@amd.com> Reported-by: Srikanth Aithal <sraithal@amd.com> Closes: https://lore.kernel.org/lkml/37usuu4yu4ok7be2hqexhmcyopluuiqj3k266z4gajc2rcj4yo@eujb23qc3zcm/ Fixes: 27bd5fdc24c0 ("KVM: SEV-ES: Prevent MSR access post VMSA encryption") Signed-off-by: Michael Roth <michael.roth@amd.com> Message-ID: <20240604233510.764949-1-michael.roth@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-06-20KVM: x86: Always sync PIR to IRR prior to scanning I/O APIC routesSean Christopherson
Sync pending posted interrupts to the IRR prior to re-scanning I/O APIC routes, irrespective of whether the I/O APIC is emulated by userspace or by KVM. If a level-triggered interrupt routed through the I/O APIC is pending or in-service for a vCPU, KVM needs to intercept EOIs on said vCPU even if the vCPU isn't the destination for the new routing, e.g. if servicing an interrupt using the old routing races with I/O APIC reconfiguration. Commit fceb3a36c29a ("KVM: x86: ioapic: Fix level-triggered EOI and userspace I/OAPIC reconfigure race") fixed the common cases, but kvm_apic_pending_eoi() only checks if an interrupt is in the local APIC's IRR or ISR, i.e. misses the uncommon case where an interrupt is pending in the PIR. Failure to intercept EOI can manifest as guest hangs with Windows 11 if the guest uses the RTC as its timekeeping source, e.g. if the VMM doesn't expose a more modern form of time to the guest. Cc: stable@vger.kernel.org Cc: Adamos Ttofari <attofari@amazon.de> Cc: Raghavendra Rao Ananta <rananta@google.com> Reviewed-by: Jim Mattson <jmattson@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-ID: <20240611014845.82795-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-06-19x86-64: word-at-a-time: improve byte count calculationsLinus Torvalds
This switches x86-64 over to using 'tzcount' instead of the integer multiply trick to turn the bytemask information into actual byte counts. We even had a comment saying that a fast bit count instruction is better than a multiply, but x86 bit counting has traditionally been "questionably fast", and so avoiding it was the right thing back in the days. Now, on any half-way modern core, using bit counting is cheaper and smaller than the large constant multiply, so let's just switch over. Note that as part of switching over to counting bits, we also do it at a different point. We used to create the byte count from the final byte mask, but once you use the 'tzcount' instruction (aka 'bsf' on older CPU's), you can actually count the leading zeroes using a value we have available earlier. In fact, we can just use the very first mask of bits that tells us whether we have any zero bytes at all. The zero bytes in the word will have the high bit set, so just doing 'tzcount' on that value and dividing by 8 will give the number of bytes that precede the first NUL character, which is exactly what we want. Note also that the input value to the tzcount is by definition not zero, since that is the condition that we already used to check the whole "do we have any zero bytes at all". So we don't need to worry about the legacy instruction behavior of pre-lzcount days when 'bsf' didn't have a result for zero input. The 32-bit code continues to use the bimple bit op trick that is faster even on newer cores, but particularly on the older 32-bit-only ones. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-06-19runtime constants: add x86 architecture supportLinus Torvalds
This implements the runtime constant infrastructure for x86, allowing the dcache d_hash() function to be generated using as a constant for hash table address followed by shift by a constant of the hash index. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-06-19x86/resctrl: Don't try to free nonexistent RMIDsDave Martin
Commit 6791e0ea3071 ("x86/resctrl: Access per-rmid structures by index") adds logic to map individual monitoring groups into a global index space used for tracking allocated RMIDs. Attempts to free the default RMID are ignored in free_rmid(), and this works fine on x86. With arm64 MPAM, there is a latent bug here however: on platforms with no monitors exposed through resctrl, each control group still gets a different monitoring group ID as seen by the hardware, since the CLOSID always forms part of the monitoring group ID. This means that when removing a control group, the code may try to free this group's default monitoring group RMID for real. If there are no monitors however, the RMID tracking table rmid_ptrs[] would be a waste of memory and is never allocated, leading to a splat when free_rmid() tries to dereference the table. One option would be to treat RMID 0 as special for every CLOSID, but this would be ugly since bookkeeping still needs to be done for these monitoring group IDs when there are monitors present in the hardware. Instead, add a gating check of resctrl_arch_mon_capable() in free_rmid(), and just do nothing if the hardware doesn't have monitors. This fix mirrors the gating checks already present in mkdir_rdt_prepare_rmid_alloc() and elsewhere. No functional change on x86. [ bp: Massage commit message. ] Fixes: 6791e0ea3071 ("x86/resctrl: Access per-rmid structures by index") Signed-off-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Tested-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/r/20240618140152.83154-1-Dave.Martin@arm.com
2024-06-18Merge tag 'efi-fixes-for-v6.10-3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi Pull EFI fixes from Ard Biesheuvel: "Another small set of EFI fixes. Only the x86 one is likely to affect any actual users (and has a cc:stable), but the issue it fixes was only observed in an unusual context (kexec in a confidential VM). - Ensure that EFI runtime services are not unmapped by PAN on ARM - Avoid freeing the memory holding the EFI memory map inadvertently on x86 - Avoid a false positive kmemleak warning on arm64" * tag 'efi-fixes-for-v6.10-3' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: efi/arm64: Fix kmemleak false positive in arm64_efi_rt_init() efi/x86: Free EFI memory map only when installing a new one. efi/arm: Disable LPAE PAN when calling EFI runtime services
2024-06-15Merge tag 'x86-urgent-2024-06-15' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: - Fix the 8 bytes get_user() logic on x86-32 - Fix build bug that creates weird & mistaken target directory under arch/x86/ * tag 'x86-urgent-2024-06-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/boot: Don't add the EFI stub to targets, again x86/uaccess: Fix missed zeroing of ia32 u64 get_user() range checking
2024-06-15efi/x86: Free EFI memory map only when installing a new one.Ard Biesheuvel
The logic in __efi_memmap_init() is shared between two different execution flows: - mapping the EFI memory map early or late into the kernel VA space, so that its entries can be accessed; - the x86 specific cloning of the EFI memory map in order to insert new entries that are created as a result of making a memory reservation via a call to efi_mem_reserve(). In the former case, the underlying memory containing the kernel's view of the EFI memory map (which may be heavily modified by the kernel itself on x86) is not modified at all, and the only thing that changes is the virtual mapping of this memory, which is different between early and late boot. In the latter case, an entirely new allocation is created that carries a new, updated version of the kernel's view of the EFI memory map. When installing this new version, the old version will no longer be referenced, and if the memory was allocated by the kernel, it will leak unless it gets freed. The logic that implements this freeing currently lives on the code path that is shared between these two use cases, but it should only apply to the latter. So move it to the correct spot. While at it, drop the dummy definition for non-x86 architectures, as that is no longer needed. Cc: <stable@vger.kernel.org> Fixes: f0ef6523475f ("efi: Fix efi_memmap_alloc() leaks") Tested-by: Ashish Kalra <Ashish.Kalra@amd.com> Link: https://lore.kernel.org/all/36ad5079-4326-45ed-85f6-928ff76483d3@amd.com Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2024-06-13Merge tag 'fixes-2024-06-13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock Pull memblock fixes from Mike Rapoport: "Fix validation of NUMA coverage. memblock_validate_numa_coverage() was checking for a unset node ID using NUMA_NO_NODE, but x86 used MAX_NUMNODES when no node ID was specified by buggy firmware. Update memblock to substitute MAX_NUMNODES with NUMA_NO_NODE in memblock_set_node() and use NUMA_NO_NODE in x86::numa_init()" * tag 'fixes-2024-06-13' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock: x86/mm/numa: Use NUMA_NO_NODE when calling memblock_set_node() memblock: make memblock_set_node() also warn about use of MAX_NUMNODES
2024-06-13x86/boot: Don't add the EFI stub to targets, againBenjamin Segall
This is a re-commit of da05b143a308 ("x86/boot: Don't add the EFI stub to targets") after the tagged patch incorrectly reverted it. vmlinux-objs-y is added to targets, with an assumption that they are all relative to $(obj); adding a $(objtree)/drivers/... path causes the build to incorrectly create a useless arch/x86/boot/compressed/drivers/... directory tree. Fix this just by using a different make variable for the EFI stub. Fixes: cb8bda8ad443 ("x86/boot/compressed: Rename efi_thunk_64.S to efi-mixed.S") Signed-off-by: Ben Segall <bsegall@google.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Cc: stable@vger.kernel.org # v6.1+ Link: https://lore.kernel.org/r/xm267ceukksz.fsf@bsegall.svl.corp.google.com
2024-06-11x86/uaccess: Fix missed zeroing of ia32 u64 get_user() range checkingKees Cook
When reworking the range checking for get_user(), the get_user_8() case on 32-bit wasn't zeroing the high register. (The jump to bad_get_user_8 was accidentally dropped.) Restore the correct error handling destination (and rename the jump to using the expected ".L" prefix). While here, switch to using a named argument ("size") for the call template ("%c4" to "%c[size]") as already used in the other call templates in this file. Found after moving the usercopy selftests to KUnit: # usercopy_test_invalid: EXPECTATION FAILED at lib/usercopy_kunit.c:278 Expected val_u64 == 0, but val_u64 == -60129542144 (0xfffffff200000000) Closes: https://lore.kernel.org/all/CABVgOSn=tb=Lj9SxHuT4_9MTjjKVxsq-ikdXC4kGHO4CfKVmGQ@mail.gmail.com Fixes: b19b74bc99b1 ("x86/mm: Rework address range check in get_user() and put_user()") Reported-by: David Gow <davidgow@google.com> Signed-off-by: Kees Cook <kees@kernel.org> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com> Tested-by: David Gow <davidgow@google.com> Link: https://lore.kernel.org/all/20240610210213.work.143-kees%40kernel.org
2024-06-08Merge tag 'x86-urgent-2024-06-08' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "Miscellaneous fixes: - Fix kexec() crash if call depth tracking is enabled - Fix SMN reads on inaccessible registers on certain AMD systems" * tag 'x86-urgent-2024-06-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/amd_nb: Check for invalid SMN reads x86/kexec: Fix bug with call depth tracking
2024-06-06x86/mm/numa: Use NUMA_NO_NODE when calling memblock_set_node()Jan Beulich
memblock_set_node() warns about using MAX_NUMNODES, see e0eec24e2e19 ("memblock: make memblock_set_node() also warn about use of MAX_NUMNODES") for details. Reported-by: Narasimhan V <Narasimhan.V@amd.com> Signed-off-by: Jan Beulich <jbeulich@suse.com> Cc: stable@vger.kernel.org [bp: commit message] Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Tested-by: Paul E. McKenney <paulmck@kernel.org> Link: https://lore.kernel.org/r/20240603141005.23261-1-bp@kernel.org Link: https://lore.kernel.org/r/abadb736-a239-49e4-ab42-ace7acdd4278@suse.com Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
2024-06-05x86/amd_nb: Check for invalid SMN readsYazen Ghannam
AMD Zen-based systems use a System Management Network (SMN) that provides access to implementation-specific registers. SMN accesses are done indirectly through an index/data pair in PCI config space. The PCI config access may fail and return an error code. This would prevent the "read" value from being updated. However, the PCI config access may succeed, but the return value may be invalid. This is in similar fashion to PCI bad reads, i.e. return all bits set. Most systems will return 0 for SMN addresses that are not accessible. This is in line with AMD convention that unavailable registers are Read-as-Zero/Writes-Ignored. However, some systems will return a "PCI Error Response" instead. This value, along with an error code of 0 from the PCI config access, will confuse callers of the amd_smn_read() function. Check for this condition, clear the return value, and set a proper error code. Fixes: ddfe43cdc0da ("x86/amd_nb: Add SMN and Indirect Data Fabric access for AMD Fam17h") Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230403164244.471141-1-yazen.ghannam@amd.com
2024-06-05KVM: x86/mmu: Don't save mmu_invalidate_seq after checking private attrTao Su
Drop the second snapshot of mmu_invalidate_seq in kvm_faultin_pfn(). Before checking the mismatch of private vs. shared, mmu_invalidate_seq is saved to fault->mmu_seq, which can be used to detect an invalidation related to the gfn occurred, i.e. KVM will not install a mapping in page table if fault->mmu_seq != mmu_invalidate_seq. Currently there is a second snapshot of mmu_invalidate_seq, which may not be same as the first snapshot in kvm_faultin_pfn(), i.e. the gfn attribute may be changed between the two snapshots, but the gfn may be mapped in page table without hindrance. Therefore, drop the second snapshot as it has no obvious benefits. Fixes: f6adeae81f35 ("KVM: x86/mmu: Handle no-slot faults at the beginning of kvm_faultin_pfn()") Signed-off-by: Tao Su <tao1.su@linux.intel.com> Message-ID: <20240528102234.2162763-1-tao1.su@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-06-03Merge branch 'kvm-fixes-6.10-1' into HEADPaolo Bonzini
* Fixes and debugging help for the #VE sanity check. Also disable it by default, even for CONFIG_DEBUG_KERNEL, because it was found to trigger spuriously (most likely a processor erratum as the exact symptoms vary by generation). * Avoid WARN() when two NMIs arrive simultaneously during an NMI-disabled situation (GIF=0 or interrupt shadow) when the processor supports virtual NMI. While generally KVM will not request an NMI window when virtual NMIs are supported, in this case it *does* have to single-step over the interrupt shadow or enable the STGI intercept, in order to deliver the latched second NMI. * Drop support for hand tuning APIC timer advancement from userspace. Since we have adaptive tuning, and it has proved to work well, drop the module parameter for manual configuration and with it a few stupid bugs that it had.
2024-06-03KVM: x86: Drop support for hand tuning APIC timer advancement from userspaceSean Christopherson
Remove support for specifying a static local APIC timer advancement value, and instead present a read-only boolean parameter to let userspace enable or disable KVM's dynamic APIC timer advancement. Realistically, it's all but impossible for userspace to specify an advancement that is more precise than what KVM's adaptive tuning can provide. E.g. a static value needs to be tuned for the exact hardware and kernel, and if KVM is using hrtimers, likely requires additional tuning for the exact configuration of the entire system. Dropping support for a userspace provided value also fixes several flaws in the interface. E.g. KVM interprets a negative value other than -1 as a large advancement, toggling between a negative and positive value yields unpredictable behavior as vCPUs will switch from dynamic to static advancement, changing the advancement in the middle of VM creation can result in different values for vCPUs within a VM, etc. Those flaws are mostly fixable, but there's almost no justification for taking on yet more complexity (it's minimal complexity, but still non-zero). The only arguments against using KVM's adaptive tuning is if a setup needs a higher maximum, or if the adjustments are too reactive, but those are arguments for letting userspace control the absolute max advancement and the granularity of each adjustment, e.g. similar to how KVM provides knobs for halt polling. Link: https://lore.kernel.org/all/20240520115334.852510-1-zhoushuling@huawei.com Cc: Shuling Zhou <zhoushuling@huawei.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-ID: <20240522010304.1650603-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-06-03KVM: SEV-ES: Delegate LBR virtualization to the processorRavi Bangoria
As documented in APM[1], LBR Virtualization must be enabled for SEV-ES guests. Although KVM currently enforces LBRV for SEV-ES guests, there are multiple issues with it: o MSR_IA32_DEBUGCTLMSR is still intercepted. Since MSR_IA32_DEBUGCTLMSR interception is used to dynamically toggle LBRV for performance reasons, this can be fatal for SEV-ES guests. For ex SEV-ES guest on Zen3: [guest ~]# wrmsr 0x1d9 0x4 KVM: entry failed, hardware error 0xffffffff EAX=00000004 EBX=00000000 ECX=000001d9 EDX=00000000 Fix this by never intercepting MSR_IA32_DEBUGCTLMSR for SEV-ES guests. No additional save/restore logic is required since MSR_IA32_DEBUGCTLMSR is of swap type A. o KVM will disable LBRV if userspace sets MSR_IA32_DEBUGCTLMSR before the VMSA is encrypted. Fix this by moving LBRV enablement code post VMSA encryption. [1]: AMD64 Architecture Programmer's Manual Pub. 40332, Rev. 4.07 - June 2023, Vol 2, 15.35.2 Enabling SEV-ES. https://bugzilla.kernel.org/attachment.cgi?id=304653 Fixes: 376c6d285017 ("KVM: SVM: Provide support for SEV-ES vCPU creation/loading") Co-developed-by: Nikunj A Dadhania <nikunj@amd.com> Signed-off-by: Nikunj A Dadhania <nikunj@amd.com> Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com> Message-ID: <20240531044644.768-4-ravi.bangoria@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-06-03KVM: SEV-ES: Disallow SEV-ES guests when X86_FEATURE_LBRV is absentRavi Bangoria
As documented in APM[1], LBR Virtualization must be enabled for SEV-ES guests. So, prevent SEV-ES guests when LBRV support is missing. [1]: AMD64 Architecture Programmer's Manual Pub. 40332, Rev. 4.07 - June 2023, Vol 2, 15.35.2 Enabling SEV-ES. https://bugzilla.kernel.org/attachment.cgi?id=304653 Fixes: 376c6d285017 ("KVM: SVM: Provide support for SEV-ES vCPU creation/loading") Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com> Message-ID: <20240531044644.768-3-ravi.bangoria@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-06-03KVM: SEV-ES: Prevent MSR access post VMSA encryptionNikunj A Dadhania
KVM currently allows userspace to read/write MSRs even after the VMSA is encrypted. This can cause unintentional issues if MSR access has side- effects. For ex, while migrating a guest, userspace could attempt to migrate MSR_IA32_DEBUGCTLMSR and end up unintentionally disabling LBRV on the target. Fix this by preventing access to those MSRs which are context switched via the VMSA, once the VMSA is encrypted. Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Nikunj A Dadhania <nikunj@amd.com> Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com> Message-ID: <20240531044644.768-2-ravi.bangoria@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-06-03x86/kexec: Fix bug with call depth trackingDavid Kaplan
The call to cc_platform_has() triggers a fault and system crash if call depth tracking is active because the GS segment has been reset by load_segments() and GS_BASE is now 0 but call depth tracking uses per-CPU variables to operate. Call cc_platform_has() earlier in the function when GS is still valid. [ bp: Massage. ] Fixes: 5d8213864ade ("x86/retbleed: Add SKL return thunk") Signed-off-by: David Kaplan <david.kaplan@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Cc: <stable@kernel.org> Link: https://lore.kernel.org/r/20240603083036.637-1-bp@kernel.org
2024-06-03x86/tsc: Remove obsolete ART to TSC conversion functionsLakshmi Sowjanya D
convert_art_to_tsc() and convert_art_ns_to_tsc() interfaces are no longer required. The conversion is now handled by the core code. Signed-off-by: Lakshmi Sowjanya D <lakshmi.sowjanya.d@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240513103813.5666-9-lakshmi.sowjanya.d@intel.com
2024-06-03x86/tsc: Provide ART base clock information for TSCLakshmi Sowjanya D
The core code provides a new mechanism to allow conversion between ART and TSC. This allows to replace the x86 specific ART/TSC conversion functions. Prepare for removal by filling in the base clock conversion information for ART and associating the base clock to the TSC clocksource. The existing conversion functions will be removed once the usage sites are converted over to the new model. [ tglx: Massaged change log ] Co-developed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Co-developed-by: Christopher S. Hall <christopher.s.hall@intel.com> Signed-off-by: Christopher S. Hall <christopher.s.hall@intel.com> Signed-off-by: Lakshmi Sowjanya D <lakshmi.sowjanya.d@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240513103813.5666-3-lakshmi.sowjanya.d@intel.com
2024-06-02Merge tag 'x86-urgent-2024-06-02' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "Miscellaneous topology parsing fixes: - Fix topology parsing regression on older CPUs in the new AMD/Hygon parser - Fix boot crash on odd Intel Quark and similar CPUs that do not fill out cpuinfo_x86::x86_clflush_size and zero out cpuinfo_x86::x86_cache_alignment as a result. Provide 32 bytes as a general fallback value. - Fix topology enumeration on certain rare CPUs where the BIOS locks certain CPUID leaves and the kernel unlocked them late, which broke with the new topology parsing code. Factor out this unlocking logic and move it earlier in the parsing sequence" * tag 'x86-urgent-2024-06-02' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/topology/intel: Unlock CPUID before evaluating anything x86/cpu: Provide default cache line size if not enumerated x86/topology/amd: Evaluate SMT in CPUID leaf 0x8000001e only on family 0x17 and greater
2024-06-02Merge tag 'sched-urgent-2024-06-02' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fix from Ingo Molnar: "Export a symbol to make life easier for instrumentation/debugging" * tag 'sched-urgent-2024-06-02' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/x86: Export 'percpu arch_freq_scale'
2024-05-31x86/topology/intel: Unlock CPUID before evaluating anythingThomas Gleixner
Intel CPUs have a MSR bit to limit CPUID enumeration to leaf two. If this bit is set by the BIOS then CPUID evaluation including topology enumeration does not work correctly as the evaluation code does not try to analyze any leaf greater than two. This went unnoticed before because the original topology code just repeated evaluation several times and managed to overwrite the initial limited information with the correct one later. The new evaluation code does it once and therefore ends up with the limited and wrong information. Cure this by unlocking CPUID right before evaluating anything which depends on the maximum CPUID leaf being greater than two instead of rereading stuff after unlock. Fixes: 22d63660c35e ("x86/cpu: Use common topology code for Intel") Reported-by: Peter Schneider <pschneider1968@googlemail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Peter Schneider <pschneider1968@googlemail.com> Cc: <stable@kernel.org> Link: https://lore.kernel.org/r/fd3f73dc-a86f-4bcf-9c60-43556a21eb42@googlemail.com
2024-05-31sched/x86: Export 'percpu arch_freq_scale'Phil Auld
Commit: 7bc263840bc3 ("sched/topology: Consolidate and clean up access to a CPU's max compute capacity") removed rq->cpu_capacity_orig in favor of using arch_scale_freq_capacity() calls. Export the underlying percpu symbol on x86 so that external trace point helper modules can be made to work again. Signed-off-by: Phil Auld <pauld@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20240530181548.2039216-1-pauld@redhat.com
2024-05-31perf/x86/intel: Add missing MODULE_DESCRIPTION() linesJeff Johnson
Fix the 'make W=1 C=1' warnings: WARNING: modpost: missing MODULE_DESCRIPTION() in arch/x86/events/intel/intel-uncore.o WARNING: modpost: missing MODULE_DESCRIPTION() in arch/x86/events/intel/intel-cstate.o Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Link: https://lore.kernel.org/r/20240530-md-arch-x86-events-intel-v1-1-8252194ed20a@quicinc.com
2024-05-31perf/x86/rapl: Add missing MODULE_DESCRIPTION() lineJeff Johnson
Fix the warning from 'make C=1 W=1': WARNING: modpost: missing MODULE_DESCRIPTION() in arch/x86/events/rapl.o Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Link: https://lore.kernel.org/r/20240530-md-arch-x86-events-v1-1-e45ffa8af99f@quicinc.com
2024-05-30x86/cpu: Provide default cache line size if not enumeratedDave Hansen
tl;dr: CPUs with CPUID.80000008H but without CPUID.01H:EDX[CLFSH] will end up reporting cache_line_size()==0 and bad things happen. Fill in a default on those to avoid the problem. Long Story: The kernel dies a horrible death if c->x86_cache_alignment (aka. cache_line_size() is 0. Normally, this value is populated from c->x86_clflush_size. Right now the code is set up to get c->x86_clflush_size from two places. First, modern CPUs get it from CPUID. Old CPUs that don't have leaf 0x80000008 (or CPUID at all) just get some sane defaults from the kernel in get_cpu_address_sizes(). The vast majority of CPUs that have leaf 0x80000008 also get ->x86_clflush_size from CPUID. But there are oddballs. Intel Quark CPUs[1] and others[2] have leaf 0x80000008 but don't set CPUID.01H:EDX[CLFSH], so they skip over filling in ->x86_clflush_size: cpuid(0x00000001, &tfms, &misc, &junk, &cap0); if (cap0 & (1<<19)) c->x86_clflush_size = ((misc >> 8) & 0xff) * 8; So they: land in get_cpu_address_sizes() and see that CPUID has level 0x80000008 and jump into the side of the if() that does not fill in c->x86_clflush_size. That assigns a 0 to c->x86_cache_alignment, and hilarity ensues in code like: buffer = kzalloc(ALIGN(sizeof(*buffer), cache_line_size()), GFP_KERNEL); To fix this, always provide a sane value for ->x86_clflush_size. Big thanks to Andy Shevchenko for finding and reporting this and also providing a first pass at a fix. But his fix was only partial and only worked on the Quark CPUs. It would not, for instance, have worked on the QEMU config. 1. https://raw.githubusercontent.com/InstLatx64/InstLatx64/master/GenuineIntel/GenuineIntel0000590_Clanton_03_CPUID.txt 2. You can also get this behavior if you use "-cpu 486,+clzero" in QEMU. [ dhansen: remove 'vp_bits_from_cpuid' reference in changelog because bpetkov brutally murdered it recently. ] Fixes: fbf6449f84bf ("x86/sev-es: Set x86_virt_bits to the correct value straight away, instead of a two-phase approach") Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Tested-by: Jörn Heusipp <osmanx@heusipp.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/20240516173928.3960193-1-andriy.shevchenko@linux.intel.com/ Link: https://lore.kernel.org/lkml/5e31cad3-ad4d-493e-ab07-724cfbfaba44@heusipp.de/ Link: https://lore.kernel.org/all/20240517200534.8EC5F33E%40davehans-spike.ostc.intel.com
2024-05-30x86/topology/amd: Evaluate SMT in CPUID leaf 0x8000001e only on family 0x17 ↵Thomas Gleixner
and greater The new AMD/HYGON topology parser evaluates the SMT information in CPUID leaf 0x8000001e unconditionally while the original code restricted it to CPUs with family 0x17 and greater. This breaks family 0x15 CPUs which advertise that leaf and have a non-zero value in the SMT section. The machine boots, but the scheduler complains loudly about the mismatch of the core IDs: WARNING: CPU: 1 PID: 0 at kernel/sched/core.c:6482 sched_cpu_starting+0x183/0x250 WARNING: CPU: 0 PID: 1 at kernel/sched/topology.c:2408 build_sched_domains+0x76b/0x12b0 Add the condition back to cure it. [ bp: Make it actually build because grandpa is not concerned with trivial stuff. :-P ] Fixes: f7fb3b2dd92c ("x86/cpu: Provide an AMD/HYGON specific topology parser") Closes: https://gitlab.archlinux.org/archlinux/packaging/packages/linux/-/issues/56 Reported-by: Tim Teichmann <teichmanntim@outlook.de> Reported-by: Christian Heusel <christian@heusel.eu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Tim Teichmann <teichmanntim@outlook.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/7skhx6mwe4hxiul64v6azhlxnokheorksqsdbp7qw6g2jduf6c@7b5pvomauugk
2024-05-27x86/mce: Remove unused variable and return value in machine_check_poll()Yazen Ghannam
The recent CMCI storm handling rework removed the last case that checks the return value of machine_check_poll(). Therefore the "error_seen" variable is no longer used, so remove it. Fixes: 3ed57b41a412 ("x86/mce: Remove old CMCI storm mitigation code") Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20240523155641.2805411-3-yazen.ghannam@amd.com Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
2024-05-27x86/mce/inject: Only write MCA_MISC when a value has been suppliedYazen Ghannam
The MCA_MISC register is used to control the MCA thresholding feature on AMD systems. Therefore, it is not generally part of the error state that a user would adjust when testing non-thresholding cases. However, MCA_MISC is unconditionally written even if a user does not supply a value. The default value of '0' will be used and clobber the register. Write the MCA_MISC register only if the user has given a value for it. Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20240523155641.2805411-2-yazen.ghannam@amd.com
2024-05-25Merge tag 'irq-urgent-2024-05-25' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fixes from Ingo Molnar: - Fix x86 IRQ vector leak caused by a CPU offlining race - Fix build failure in the riscv-imsic irqchip driver caused by an API-change semantic conflict - Fix use-after-free in irq_find_at_or_after() * tag 'irq-urgent-2024-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq/irqdesc: Prevent use-after-free in irq_find_at_or_after() genirq/cpuhotplug, x86/vector: Prevent vector leak during CPU offline irqchip/riscv-imsic: Fixup riscv_ipi_set_virq_range() conflict