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2019-06-22x86/elf: Enumerate kernel FSGSBASE capability in AT_HWCAP2Andi Kleen1-1/+3
The kernel needs to explicitly enable FSGSBASE. So, the application needs to know if it can safely use these instructions. Just looking at the CPUID bit is not enough because it may be running in a kernel that does not enable the instructions. One way for the application would be to just try and catch the SIGILL. But that is difficult to do in libraries which may not want to overwrite the signal handlers of the main application. Enumerate the enabled FSGSBASE capability in bit 1 of AT_HWCAP2 in the ELF aux vector. AT_HWCAP2 is already used by PPC for similar purposes. The application can access it open coded or by using the getauxval() function in newer versions of glibc. [ tglx: Massaged changelog ] Signed-off-by: Andi Kleen <[email protected]> Signed-off-by: Chang S. Bae <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Ravi Shankar <[email protected]> Cc: H. Peter Anvin <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2019-06-22x86/cpu: Enable FSGSBASE on 64bit by default and add a chicken bitAndy Lutomirski1-18/+14
Now that FSGSBASE is fully supported, remove unsafe_fsgsbase, enable FSGSBASE by default, and add nofsgsbase to disable it. Signed-off-by: Andy Lutomirski <[email protected]> Signed-off-by: Chang S. Bae <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Andi Kleen <[email protected]> Cc: Ravi Shankar <[email protected]> Cc: H. Peter Anvin <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2019-06-22x86/cpu: Add 'unsafe_fsgsbase' to enable CR4.FSGSBASEAndy Lutomirski1-0/+24
This is temporary. It will allow the next few patches to be tested incrementally. Setting unsafe_fsgsbase is a root hole. Don't do it. Signed-off-by: Andy Lutomirski <[email protected]> Signed-off-by: Chang S. Bae <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Andi Kleen <[email protected]> Reviewed-by: Andy Lutomirski <[email protected]> Cc: Ravi Shankar <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Randy Dunlap <[email protected]> Cc: H. Peter Anvin <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2019-06-20x86/resctrl: Prevent possible overrun during bitmap operationsReinette Chatre1-19/+16
While the DOC at the beginning of lib/bitmap.c explicitly states that "The number of valid bits in a given bitmap does _not_ need to be an exact multiple of BITS_PER_LONG.", some of the bitmap operations do indeed access BITS_PER_LONG portions of the provided bitmap no matter the size of the provided bitmap. For example, if find_first_bit() is provided with an 8 bit bitmap the operation will access BITS_PER_LONG bits from the provided bitmap. While the operation ensures that these extra bits do not affect the result, the memory is still accessed. The capacity bitmasks (CBMs) are typically stored in u32 since they can never exceed 32 bits. A few instances exist where a bitmap_* operation is performed on a CBM by simply pointing the bitmap operation to the stored u32 value. The consequence of this pattern is that some bitmap_* operations will access out-of-bounds memory when interacting with the provided CBM. This same issue has previously been addressed with commit 49e00eee0061 ("x86/intel_rdt: Fix out-of-bounds memory access in CBM tests") but at that time not all instances of the issue were fixed. Fix this by using an unsigned long to store the capacity bitmask data that is passed to bitmap functions. Fixes: e651901187ab ("x86/intel_rdt: Introduce "bit_usage" to display cache allocations details") Fixes: f4e80d67a527 ("x86/intel_rdt: Resctrl files reflect pseudo-locked information") Fixes: 95f0b77efa57 ("x86/intel_rdt: Initialize new resource group with sane defaults") Signed-off-by: Reinette Chatre <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Cc: Fenghua Yu <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: stable <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Tony Luck <[email protected]> Cc: x86-ml <[email protected]> Link: https://lkml.kernel.org/r/58c9b6081fd9bf599af0dfc01a6fdd335768efef.1560975645.git.reinette.chatre@intel.com
2019-06-20x86/cpufeatures: Enumerate the new AVX512 BFLOAT16 instructionsFenghua Yu2-0/+7
AVX512 BFLOAT16 instructions support 16-bit BFLOAT16 floating-point format (BF16) for deep learning optimization. BF16 is a short version of 32-bit single-precision floating-point format (FP32) and has several advantages over 16-bit half-precision floating-point format (FP16). BF16 keeps FP32 accumulation after multiplication without loss of precision, offers more than enough range for deep learning training tasks, and doesn't need to handle hardware exception. AVX512 BFLOAT16 instructions are enumerated in CPUID.7.1:EAX[bit 5] AVX512_BF16. CPUID.7.1:EAX contains only feature bits. Reuse the currently empty word 12 as a pure features word to hold the feature bits including AVX512_BF16. Detailed information of the CPUID bit and AVX512 BFLOAT16 instructions can be found in the latest Intel Architecture Instruction Set Extensions and Future Features Programming Reference. [ bp: Check CPUID(7) subleaf validity before accessing subleaf 1. ] Signed-off-by: Fenghua Yu <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Cc: "Chang S. Bae" <[email protected]> Cc: Frederic Weisbecker <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jann Horn <[email protected]> Cc: Masahiro Yamada <[email protected]> Cc: Michael Ellerman <[email protected]> Cc: Nadav Amit <[email protected]> Cc: Paolo Bonzini <[email protected]> Cc: Pavel Tatashin <[email protected]> Cc: Peter Feiner <[email protected]> Cc: Radim Krcmar <[email protected]> Cc: "Rafael J. Wysocki" <[email protected]> Cc: "Ravi V Shankar" <[email protected]> Cc: Robert Hoo <[email protected]> Cc: "Sean J Christopherson" <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Thomas Lendacky <[email protected]> Cc: x86 <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2019-06-20x86/cpufeatures: Combine word 11 and 12 into a new scattered features wordFenghua Yu3-23/+22
It's a waste for the four X86_FEATURE_CQM_* feature bits to occupy two whole feature bits words. To better utilize feature words, re-define word 11 to host scattered features and move the four X86_FEATURE_CQM_* features into Linux defined word 11. More scattered features can be added in word 11 in the future. Rename leaf 11 in cpuid_leafs to CPUID_LNX_4 to reflect it's a Linux-defined leaf. Rename leaf 12 as CPUID_DUMMY which will be replaced by a meaningful name in the next patch when CPUID.7.1:EAX occupies world 12. Maximum number of RMID and cache occupancy scale are retrieved from CPUID.0xf.1 after scattered CQM features are enumerated. Carve out the code into a separate function. KVM doesn't support resctrl now. So it's safe to move the X86_FEATURE_CQM_* features to scattered features word 11 for KVM. Signed-off-by: Fenghua Yu <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Cc: Aaron Lewis <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Babu Moger <[email protected]> Cc: "Chang S. Bae" <[email protected]> Cc: "Sean J Christopherson" <[email protected]> Cc: Frederic Weisbecker <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jann Horn <[email protected]> Cc: Juergen Gross <[email protected]> Cc: Konrad Rzeszutek Wilk <[email protected]> Cc: kvm ML <[email protected]> Cc: Masahiro Yamada <[email protected]> Cc: Masami Hiramatsu <[email protected]> Cc: Nadav Amit <[email protected]> Cc: Paolo Bonzini <[email protected]> Cc: Pavel Tatashin <[email protected]> Cc: Peter Feiner <[email protected]> Cc: "Peter Zijlstra (Intel)" <[email protected]> Cc: "Radim Krčmář" <[email protected]> Cc: "Rafael J. Wysocki" <[email protected]> Cc: Ravi V Shankar <[email protected]> Cc: Sherry Hurwitz <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Thomas Lendacky <[email protected]> Cc: x86 <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2019-06-20x86/cpufeatures: Carve out CQM features retrievalBorislav Petkov1-27/+33
... into a separate function for better readability. Split out from a patch from Fenghua Yu <[email protected]> to keep the mechanical, sole code movement separate for easy review. No functional changes. Signed-off-by: Borislav Petkov <[email protected]> Cc: Fenghua Yu <[email protected]> Cc: [email protected]
2019-06-19x86/cacheinfo: Fix a -Wtype-limits warningQian Cai1-2/+1
cpuinfo_x86.x86_model is an unsigned type, so comparing against zero will generate a compilation warning: arch/x86/kernel/cpu/cacheinfo.c: In function 'cacheinfo_amd_init_llc_id': arch/x86/kernel/cpu/cacheinfo.c:662:19: warning: comparison is always true \ due to limited range of data type [-Wtype-limits] Remove the unnecessary lower bound check. [ bp: Massage. ] Fixes: 68091ee7ac3c ("x86/CPU/AMD: Calculate last level cache ID from number of sharing threads") Signed-off-by: Qian Cai <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Reviewed-by: Sean Christopherson <[email protected]> Cc: "Gustavo A. R. Silva" <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Masami Hiramatsu <[email protected]> Cc: Pu Wen <[email protected]> Cc: Suravee Suthikulpanit <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: x86-ml <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2019-06-19x86/microcode: Fix the microcode load on CPU hotplug for realThomas Gleixner1-5/+10
A recent change moved the microcode loader hotplug callback into the early startup phase which is running with interrupts disabled. It missed that the callbacks invoke sysfs functions which might sleep causing nice 'might sleep' splats with proper debugging enabled. Split the callbacks and only load the microcode in the early startup phase and move the sysfs handling back into the later threaded and preemptible bringup phase where it was before. Fixes: 78f4e932f776 ("x86/microcode, cpuhotplug: Add a microcode loader CPU hotplug callback") Signed-off-by: Thomas Gleixner <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: [email protected] Cc: x86-ml <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2019-06-17Merge tag 'v5.2-rc5' into sched/core, to pick up fixesIngo Molnar15-107/+27
Signed-off-by: Ingo Molnar <[email protected]>
2019-06-16Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds3-2/+10
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "The accumulated fixes from this and last week: - Fix vmalloc TLB flush and map range calculations which lead to stale TLBs, spurious faults and other hard to diagnose issues. - Use fault_in_pages_writable() for prefaulting the user stack in the FPU code as it's less fragile than the current solution - Use the PF_KTHREAD flag when checking for a kernel thread instead of current->mm as the latter can give the wrong answer due to use_mm() - Compute the vmemmap size correctly for KASLR and 5-Level paging. Otherwise this can end up with a way too small vmemmap area. - Make KASAN and 5-level paging work again by making sure that all invalid bits are masked out when computing the P4D offset. This worked before but got broken recently when the LDT remap area was moved. - Prevent a NULL pointer dereference in the resource control code which can be triggered with certain mount options when the requested resource is not available. - Enforce ordering of microcode loading vs. perf initialization on secondary CPUs. Otherwise perf tries to access a non-existing MSR as the boot CPU marked it as available. - Don't stop the resource control group walk early otherwise the control bitmaps are not updated correctly and become inconsistent. - Unbreak kgdb by returning 0 on success from kgdb_arch_set_breakpoint() instead of an error code. - Add more Icelake CPU model defines so depending changes can be queued in other trees" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/microcode, cpuhotplug: Add a microcode loader CPU hotplug callback x86/kasan: Fix boot with 5-level paging and KASAN x86/fpu: Don't use current->mm to check for a kthread x86/kgdb: Return 0 from kgdb_arch_set_breakpoint() x86/resctrl: Prevent NULL pointer dereference when local MBM is disabled x86/resctrl: Don't stop walking closids when a locksetup group is found x86/fpu: Update kernel's FPU state before using for the fsave header x86/mm/KASLR: Compute the size of the vmemmap section properly x86/fpu: Use fault_in_pages_writeable() for pre-faulting x86/CPU: Add more Icelake model numbers mm/vmalloc: Avoid rare case of flushing TLB with weird arguments mm/vmalloc: Fix calculation of direct map addr range
2019-06-15x86/microcode, cpuhotplug: Add a microcode loader CPU hotplug callbackBorislav Petkov1-1/+1
Adric Blake reported the following warning during suspend-resume: Enabling non-boot CPUs ... x86: Booting SMP configuration: smpboot: Booting Node 0 Processor 1 APIC 0x2 unchecked MSR access error: WRMSR to 0x10f (tried to write 0x0000000000000000) \ at rIP: 0xffffffff8d267924 (native_write_msr+0x4/0x20) Call Trace: intel_set_tfa intel_pmu_cpu_starting ? x86_pmu_dead_cpu x86_pmu_starting_cpu cpuhp_invoke_callback ? _raw_spin_lock_irqsave notify_cpu_starting start_secondary secondary_startup_64 microcode: sig=0x806ea, pf=0x80, revision=0x96 microcode: updated to revision 0xb4, date = 2019-04-01 CPU1 is up The MSR in question is MSR_TFA_RTM_FORCE_ABORT and that MSR is emulated by microcode. The log above shows that the microcode loader callback happens after the PMU restoration, leading to the conjecture that because the microcode hasn't been updated yet, that MSR is not present yet, leading to the #GP. Add a microcode loader-specific hotplug vector which comes before the PERF vectors and thus executes earlier and makes sure the MSR is present. Fixes: 400816f60c54 ("perf/x86/intel: Implement support for TSX Force Abort") Reported-by: Adric Blake <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Reviewed-by: Thomas Gleixner <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: <[email protected]> Cc: [email protected] Link: https://bugzilla.kernel.org/show_bug.cgi?id=203637
2019-06-14Merge tag 'v5.2-rc4' into mauroJonathan Corbet25-125/+33
We need to pick up post-rc1 changes to various document files so they don't get lost in Mauro's massive RST conversion push.
2019-06-14x86/mce: Do not check return value of debugfs_create functionsGreg Kroah-Hartman3-54/+13
When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this. The only way this can fail is if: * debugfs superblock can not be pinned - something really went wrong with the vfs layer. * file is created with same name - the caller's fault. * new_inode() fails - happens if memory is exhausted. so failing to clean up debugfs properly is the least of the system's sproblems in uch a situation. [ bp: Extend commit message, remove unused err var in inject_init(). ] Signed-off-by: Greg Kroah-Hartman <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: linux-edac <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Tony Luck <[email protected]> Cc: x86-ml <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2019-06-12x86/resctrl: Prevent NULL pointer dereference when local MBM is disabledPrarit Bhargava1-0/+3
Booting with kernel parameter "rdt=cmt,mbmtotal,memlocal,l3cat,mba" and executing "mount -t resctrl resctrl -o mba_MBps /sys/fs/resctrl" results in a NULL pointer dereference on systems which do not have local MBM support enabled.. BUG: kernel NULL pointer dereference, address: 0000000000000020 PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI CPU: 0 PID: 722 Comm: kworker/0:3 Not tainted 5.2.0-0.rc3.git0.1.el7_UNSUPPORTED.x86_64 #2 Workqueue: events mbm_handle_overflow RIP: 0010:mbm_handle_overflow+0x150/0x2b0 Only enter the bandwith update loop if the system has local MBM enabled. Fixes: de73f38f7680 ("x86/intel_rdt/mba_sc: Feedback loop to dynamically update mem bandwidth") Signed-off-by: Prarit Bhargava <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Cc: Fenghua Yu <[email protected]> Cc: Reinette Chatre <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected]
2019-06-12x86/resctrl: Don't stop walking closids when a locksetup group is foundJames Morse1-1/+6
When a new control group is created __init_one_rdt_domain() walks all the other closids to calculate the sets of used and unused bits. If it discovers a pseudo_locksetup group, it breaks out of the loop. This means any later closid doesn't get its used bits added to used_b. These bits will then get set in unused_b, and added to the new control group's configuration, even if they were marked as exclusive for a later closid. When encountering a pseudo_locksetup group, we should continue. This is because "a resource group enters 'pseudo-locked' mode after the schemata is written while the resource group is in 'pseudo-locksetup' mode." When we find a pseudo_locksetup group, its configuration is expected to be overwritten, we can skip it. Fixes: dfe9674b04ff6 ("x86/intel_rdt: Enable entering of pseudo-locksetup mode") Signed-off-by: James Morse <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Acked-by: Reinette Chatre <[email protected]> Cc: Fenghua Yu <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: H Peter Avin <[email protected]> Cc: <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2019-06-11x86/acrn: Use HYPERVISOR_CALLBACK_VECTOR for ACRN guest upcall vectorZhao Yakui1-0/+30
Use the HYPERVISOR_CALLBACK_VECTOR to notify an ACRN guest. Co-developed-by: Jason Chen CJ <[email protected]> Signed-off-by: Jason Chen CJ <[email protected]> Signed-off-by: Zhao Yakui <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Reviewed-by: Thomas Gleixner <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: x86-ml <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2019-06-11x86: Add support for Linux guests on an ACRN hypervisorZhao Yakui3-0/+44
ACRN is an open-source hypervisor maintained by The Linux Foundation. It is built for embedded IOT with small footprint and real-time features. Add ACRN guest support so that it allows Linux to be booted under the ACRN hypervisor. This adds only the barebones implementation. [ bp: Massage commit message and help text. ] Co-developed-by: Jason Chen CJ <[email protected]> Signed-off-by: Jason Chen CJ <[email protected]> Signed-off-by: Zhao Yakui <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Reviewed-by: Thomas Gleixner <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: x86-ml <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2019-06-11x86/MCE: Determine MCA banks' init state properlyYazen Ghannam1-0/+39
The OS is expected to write all bits to MCA_CTL for each bank, thus enabling error reporting in all banks. However, some banks may be unused in which case the registers for such banks are Read-as-Zero/Writes-Ignored. Also, the OS may avoid setting some control bits because of quirks, etc. A bank can be considered uninitialized if the MCA_CTL register returns zero. This is because either the OS did not write anything or because the hardware is enforcing RAZ/WI for the bank. Set a bank's init value based on if the control bits are set or not in hardware. Return an error code in the sysfs interface for uninitialized banks. Do a final bank init check in a separate function which is not part of any user-controlled code flows. This is so a user may enable/disable a bank during runtime without having to restart their system. [ bp: Massage a bit. Discover bank init state at boot. ] Signed-off-by: Yazen Ghannam <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: "[email protected]" <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Tony Luck <[email protected]> Cc: "[email protected]" <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2019-06-11x86/MCE: Make the number of MCA banks a per-CPU variableYazen Ghannam3-30/+36
The number of MCA banks is provided per logical CPU. Historically, this number has been the same across all CPUs, but this is not an architectural guarantee. Future AMD systems may have MCA bank counts that vary between logical CPUs in a system. This issue was partially addressed in 006c077041dc ("x86/mce: Handle varying MCA bank counts") by allocating structures using the maximum number of MCA banks and by saving the maximum MCA bank count in a system as the global count. This means that some extra structures are allocated. Also, this means that CPUs will spend more time in the #MC and other handlers checking extra MCA banks. Thus, define the number of MCA banks as a per-CPU variable. [ bp: Make mce_num_banks an unsigned int. ] Signed-off-by: Yazen Ghannam <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: "[email protected]" <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Tony Luck <[email protected]> Cc: "[email protected]" <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2019-06-11x86/MCE/AMD: Don't cache block addresses on SMCA systemsYazen Ghannam1-36/+37
On legacy systems, the addresses of the MCA_MISC* registers need to be recursively discovered based on a Block Pointer field in the registers. On Scalable MCA systems, the register space is fixed, and particular addresses can be derived by regular offsets for bank and register type. This fixed address space includes the MCA_MISC* registers. MCA_MISC0 is always available for each MCA bank. MCA_MISC1 through MCA_MISC4 are considered available if MCA_MISC0[BlkPtr]=1. Cache the value of MCA_MISC0[BlkPtr] for each bank and per CPU. This needs to be done only during init. The values should be saved per CPU to accommodate heterogeneous SMCA systems. Redo smca_get_block_address() to directly return the block addresses. Signed-off-by: Yazen Ghannam <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: "[email protected]" <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Tony Luck <[email protected]> Cc: "[email protected]" <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2019-06-11x86/MCE: Make mce_banks a per-CPU arrayYazen Ghannam1-28/+48
Current AMD systems have unique MCA banks per logical CPU even though the type of the banks may all align to the same bank number. Each CPU will have control of a set of MCA banks in the hardware and these are not shared with other CPUs. For example, bank 0 may be the Load-Store Unit on every logical CPU, but each bank 0 is a unique structure in the hardware. In other words, there isn't a *single* Load-Store Unit at MCA bank 0 that all logical CPUs share. This idea extends even to non-core MCA banks. For example, CPU0 and CPU4 may see a Unified Memory Controller at bank 15, but each CPU is actually seeing a unique hardware structure that is not shared with other CPUs. Because the MCA banks are all unique hardware structures, it would be good to control them in a more granular way. For example, if there is a known issue with the Floating Point Unit on CPU5 and a user wishes to disable an error type on the Floating Point Unit, then it would be good to do this only for CPU5 rather than all CPUs. Also, future AMD systems may have heterogeneous MCA banks. Meaning the bank numbers may not necessarily represent the same types between CPUs. For example, bank 20 visible to CPU0 may be a Unified Memory Controller and bank 20 visible to CPU4 may be a Coherent Slave. So granular control will be even more necessary should the user wish to control specific MCA banks. Split the device attributes from struct mce_bank leaving only the MCA bank control fields. Make struct mce_banks[] per_cpu in order to have more granular control over individual MCA banks in the hardware. Allocate the device attributes statically based on the maximum number of MCA banks supported. The sysfs interface will use as many as needed per CPU. Currently, this is set to mca_cfg.banks, but will be changed to a per_cpu bank count in a future patch. Allocate the MCA control bits statically. This is in order to avoid locking warnings when memory is allocated during secondary CPUs' init sequences. Also, remove the now unnecessary return values from __mcheck_cpu_mce_banks_init() and __mcheck_cpu_cap_init(). Redo the sysfs store/show functions to handle the per_cpu mce_banks[]. [ bp: s/mce_banks_percpu/mce_banks_array/g ] [ Locking issue reported by ] Reported-by: kernel test robot <[email protected]> Signed-off-by: Yazen Ghannam <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: "[email protected]" <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Tony Luck <[email protected]> Cc: "[email protected]" <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2019-06-11x86/MCE: Make struct mce_banks[] staticYazen Ghannam2-11/+10
The struct mce_banks[] array is only used in mce/core.c so move its definition there and make it static. Also, change the "init" field to bool type. Signed-off-by: Yazen Ghannam <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: linux-edac <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Tony Luck <[email protected]> Cc: "[email protected]" <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2019-06-10x86/resctrl: Use _ASM_BX to avoid ifdefferyUros Bizjak1-5/+1
Use the _ASM_BX macro which expands to either %rbx or %ebx, depending on the 32-bit or 64-bit config selected. Signed-off-by: Uros Bizjak <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Acked-by: Reinette Chatre <[email protected]> Cc: Fenghua Yu <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: x86-ml <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2019-06-08Merge tag 'spdx-5.2-rc4' of ↵Linus Torvalds12-83/+12
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull yet more SPDX updates from Greg KH: "Another round of SPDX header file fixes for 5.2-rc4 These are all more "GPL-2.0-or-later" or "GPL-2.0-only" tags being added, based on the text in the files. We are slowly chipping away at the 700+ different ways people tried to write the license text. All of these were reviewed on the spdx mailing list by a number of different people. We now have over 60% of the kernel files covered with SPDX tags: $ ./scripts/spdxcheck.py -v 2>&1 | grep Files Files checked: 64533 Files with SPDX: 40392 Files with errors: 0 I think the majority of the "easy" fixups are now done, it's now the start of the longer-tail of crazy variants to wade through" * tag 'spdx-5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (159 commits) treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 450 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 449 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 448 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 446 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 445 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 444 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 443 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 442 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 440 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 438 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 437 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 436 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 435 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 434 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 433 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 432 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 431 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 430 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 429 ...
2019-06-08docs: fix broken documentation linksMauro Carvalho Chehab1-1/+1
Mostly due to x86 and acpi conversion, several documentation links are still pointing to the old file. Fix them. Signed-off-by: Mauro Carvalho Chehab <[email protected]> Reviewed-by: Wolfram Sang <[email protected]> Reviewed-by: Sven Van Asbroeck <[email protected]> Reviewed-by: Bhupesh Sharma <[email protected]> Acked-by: Mark Brown <[email protected]> Signed-off-by: Jonathan Corbet <[email protected]>
2019-06-07Merge branch 'pm-x86'Rafael J. Wysocki2-22/+5
* pm-x86: x86/power: Fix 'nosmt' vs hibernation triple fault during resume x86: intel_epb: Do not build when CONFIG_PM is unset
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441Thomas Gleixner2-10/+2
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation version 2 of the license extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 315 file(s). Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Allison Randal <[email protected]> Reviewed-by: Armijn Hemel <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 437Thomas Gleixner2-4/+2
Based on 1 normalized pattern(s): this file is licensed under gplv2 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 22 file(s). Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Armijn Hemel <[email protected]> Reviewed-by: Allison Randal <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 353Thomas Gleixner1-3/+1
Based on 1 normalized pattern(s): licensed under the terms of the gnu general public license version 2 see file copying for details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 1 file(s). Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Armijn Hemel <[email protected]> Reviewed-by: Allison Randal <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 347Thomas Gleixner1-3/+1
Based on 1 normalized pattern(s): your use of this code is subject to the terms and conditions of the gnu general public license version 2 see copying or http www gnu org licenses gpl html extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 3 file(s). Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Kate Stewart <[email protected]> Reviewed-by: Allison Randal <[email protected]> Reviewed-by: Armijn Hemel <[email protected]> Reviewed-by: Alexios Zavras <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 335Thomas Gleixner1-14/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms and conditions of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 51 franklin st fifth floor boston ma 02110 1301 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 111 file(s). Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexios Zavras <[email protected]> Reviewed-by: Allison Randal <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333Thomas Gleixner1-13/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 136 file(s). Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexios Zavras <[email protected]> Reviewed-by: Allison Randal <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 288Thomas Gleixner4-36/+4
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms and conditions of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 263 file(s). Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Allison Randal <[email protected]> Reviewed-by: Alexios Zavras <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2019-06-03sched/core: Provide a pointer to the valid CPU maskSebastian Andrzej Siewior1-1/+1
In commit: 4b53a3412d66 ("sched/core: Remove the tsk_nr_cpus_allowed() wrapper") the tsk_nr_cpus_allowed() wrapper was removed. There was not much difference in !RT but in RT we used this to implement migrate_disable(). Within a migrate_disable() section the CPU mask is restricted to single CPU while the "normal" CPU mask remains untouched. As an alternative implementation Ingo suggested to use: struct task_struct { const cpumask_t *cpus_ptr; cpumask_t cpus_mask; }; with t->cpus_ptr = &t->cpus_mask; In -RT we then can switch the cpus_ptr to: t->cpus_ptr = &cpumask_of(task_cpu(p)); in a migration disabled region. The rules are simple: - Code that 'uses' ->cpus_allowed would use the pointer. - Code that 'modifies' ->cpus_allowed would use the direct mask. Signed-off-by: Sebastian Andrzej Siewior <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Reviewed-by: Thomas Gleixner <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2019-06-02Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds1-2/+5
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "Two fixes: a quirk for KVM guests running on certain AMD CPUs, and a KASAN related build fix" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/CPU/AMD: Don't force the CPB cap when running under a hypervisor x86/boot: Provide KASAN compatible aliases for string routines
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 172Thomas Gleixner1-8/+1
Based on 1 normalized pattern(s): this file may be distributed under the terms of the gnu general public license version 2 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 9 file(s). Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Allison Randal <[email protected]> Reviewed-by: Kate Stewart <[email protected]> Reviewed-by: Richard Fontana <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152Thomas Gleixner2-10/+2
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Allison Randal <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2019-05-30x86: intel_epb: Do not build when CONFIG_PM is unsetRafael J. Wysocki2-22/+5
Commit 9ed0985332a6 ("x86: intel_epb: Take CONFIG_PM into account") prevented the majority of the Performance and Energy Bias Hint (EPB) handling code from being built when CONFIG_PM is unset to fix a regression introduced by commit b9c273babce7 ("PM / arch: x86: MSR_IA32_ENERGY_PERF_BIAS sysfs interface"). In hindsight, however, it would be better to skip all of the EPB handling code for CONFIG_PM unset as there really is no reason for it to be there in that case. Namely, if the EPB is not touched by the kernel at all with CONFIG_PM unset, there is no need to worry about modifying the EPB inadvertently on CPU online and since the system will not suspend or hibernate then, there is no need to worry about possible modifications of the EPB by the platform firmware during system-wide PM transitions. For this reason, revert the changes made by commit 9ed0985332a6 and only allow intel_epb.o to be built when CONFIG_PM is set. Note that this changes the behavior of the kernels built with CONFIG_PM unset as they will not modify the EPB on boot if it is zero initially any more, so it is not a fix strictly speaking, but users building their kernels with CONFIG_PM unset really should not expect them to take energy efficiency into account. Moreover, if CONFIG_PM is unset for performance reasons, leaving EPB as set initially by the platform firmware will actually be consistent with the user's expectations. Signed-off-by: Rafael J. Wysocki <[email protected]> Acked-by: Ingo Molnar <[email protected]>
2019-05-27signal: Remove task parameter from force_sigEric W. Biederman1-1/+1
All of the remaining callers pass current into force_sig so remove the task parameter to make this obvious and to make misuse more difficult in the future. This also makes it clear force_sig passes current into force_sig_info. Signed-off-by: "Eric W. Biederman" <[email protected]>
2019-05-25no need to protect against put_user_ns(NULL)Al Viro1-2/+1
it's a no-op Signed-off-by: Al Viro <[email protected]>
2019-05-24x86/CPU/AMD: Don't force the CPB cap when running under a hypervisorFrank van der Linden1-2/+5
For F17h AMD CPUs, the CPB capability ('Core Performance Boost') is forcibly set, because some versions of that chip incorrectly report that they do not have it. However, a hypervisor may filter out the CPB capability, for good reasons. For example, KVM currently does not emulate setting the CPB bit in MSR_K7_HWCR, and unchecked MSR access errors will be thrown when trying to set it as a guest: unchecked MSR access error: WRMSR to 0xc0010015 (tried to write 0x0000000001000011) at rIP: 0xffffffff890638f4 (native_write_msr+0x4/0x20) Call Trace: boost_set_msr+0x50/0x80 [acpi_cpufreq] cpuhp_invoke_callback+0x86/0x560 sort_range+0x20/0x20 cpuhp_thread_fun+0xb0/0x110 smpboot_thread_fn+0xef/0x160 kthread+0x113/0x130 kthread_create_worker_on_cpu+0x70/0x70 ret_from_fork+0x35/0x40 To avoid this issue, don't forcibly set the CPB capability for a CPU when running under a hypervisor. Signed-off-by: Frank van der Linden <[email protected]> Acked-by: Borislav Petkov <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Fixes: 0237199186e7 ("x86/CPU/AMD: Set the CPB bit unconditionally on F17h") Link: http://lkml.kernel.org/r/20190522221745.GA15789@dev-dsk-fllinden-2c-c1893d73.us-west-2.amazon.com [ Minor edits to the changelog. ] Signed-off-by: Ingo Molnar <[email protected]>
2019-05-23x86/topology: Define topology_logical_die_id()Len Brown1-0/+1
Define topology_logical_die_id() ala existing topology_logical_package_id() Signed-off-by: Len Brown <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Tested-by: Zhang Rui <[email protected]> Reviewed-by: Ingo Molnar <[email protected]> Acked-by: Peter Zijlstra (Intel) <[email protected]> Link: https://lkml.kernel.org/r/2f3526e25ae14fbeff26fb26e877d159df8946d9.1557769318.git.len.brown@intel.com
2019-05-23x86/topology: Create topology_max_die_per_package()Len Brown1-1/+4
topology_max_packages() is available to size resources to cover all packages in the system. But now multi-die/package systems are coming up, and some resources are per-die. Create topology_max_die_per_package(), for detecting multi-die/package systems, and sizing any per-die resources. Signed-off-by: Len Brown <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Ingo Molnar <[email protected]> Acked-by: Peter Zijlstra (Intel) <[email protected]> Link: https://lkml.kernel.org/r/e6eaf384571ae52ac7d0ca41510b7fb7d2fda0e4.1557769318.git.len.brown@intel.com
2019-05-23x86/topology: Add CPUID.1F multi-die/package supportLen Brown1-19/+66
Some new systems have multiple software-visible die within each package. Update Linux parsing of the Intel CPUID "Extended Topology Leaf" to handle either CPUID.B, or the new CPUID.1F. Add cpuinfo_x86.die_id and cpuinfo_x86.max_dies to store the result. die_id will be non-zero only for multi-die/package systems. Signed-off-by: Len Brown <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Ingo Molnar <[email protected]> Acked-by: Peter Zijlstra (Intel) <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/7b23d2d26d717b8e14ba137c94b70943f1ae4b5c.1557769318.git.len.brown@intel.com
2019-05-21treewide: Add SPDX license identifier - Makefile/KconfigThomas Gleixner2-0/+2
Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
2019-05-21treewide: Add SPDX license identifier for missed filesThomas Gleixner6-0/+6
Add SPDX license identifiers to all files which: - Have no license information of any form - Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
2019-05-15Merge tag 'pm-5.2-rc1-2' of ↵Linus Torvalds1-1/+21
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull more power management updates from Rafael Wysocki: "These fix a recent regression causing kernels built with CONFIG_PM unset to crash on systems that support the Performance and Energy Bias Hint (EPB), clean up the cpufreq core and some users of transition notifiers and introduce a new power domain flag into the generic power domains framework (genpd). Specifics: - Fix recent regression causing kernels built with CONFIG_PM unset to crash on systems that support the Performance and Energy Bias Hint (EPB) by avoiding to compile the EPB-related code depending on CONFIG_PM when it is unset (Rafael Wysocki). - Clean up the transition notifier invocation code in the cpufreq core and change some users of cpufreq transition notifiers accordingly (Viresh Kumar). - Change MAINTAINERS to cover the schedutil governor as part of cpufreq (Viresh Kumar). - Simplify cpufreq_init_policy() to avoid redundant computations (Yue Hu). - Add explanatory comment to the cpufreq core (Rafael Wysocki). - Introduce a new flag, GENPD_FLAG_RPM_ALWAYS_ON, to the generic power domains (genpd) framework along with the first user of it (Leonard Crestez)" * tag 'pm-5.2-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: soc: imx: gpc: Use GENPD_FLAG_RPM_ALWAYS_ON for ERR009619 PM / Domains: Add GENPD_FLAG_RPM_ALWAYS_ON flag cpufreq: Update MAINTAINERS to include schedutil governor cpufreq: Don't find governor for setpolicy drivers in cpufreq_init_policy() cpufreq: Explain the kobject_put() in cpufreq_policy_alloc() cpufreq: Call transition notifier only once for each policy x86: intel_epb: Take CONFIG_PM into account
2019-05-14Merge branch 'x86-mds-for-linus' of ↵Linus Torvalds2-54/+202
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 MDS mitigations from Thomas Gleixner: "Microarchitectural Data Sampling (MDS) is a hardware vulnerability which allows unprivileged speculative access to data which is available in various CPU internal buffers. This new set of misfeatures has the following CVEs assigned: CVE-2018-12126 MSBDS Microarchitectural Store Buffer Data Sampling CVE-2018-12130 MFBDS Microarchitectural Fill Buffer Data Sampling CVE-2018-12127 MLPDS Microarchitectural Load Port Data Sampling CVE-2019-11091 MDSUM Microarchitectural Data Sampling Uncacheable Memory MDS attacks target microarchitectural buffers which speculatively forward data under certain conditions. Disclosure gadgets can expose this data via cache side channels. Contrary to other speculation based vulnerabilities the MDS vulnerability does not allow the attacker to control the memory target address. As a consequence the attacks are purely sampling based, but as demonstrated with the TLBleed attack samples can be postprocessed successfully. The mitigation is to flush the microarchitectural buffers on return to user space and before entering a VM. It's bolted on the VERW instruction and requires a microcode update. As some of the attacks exploit data structures shared between hyperthreads, full protection requires to disable hyperthreading. The kernel does not do that by default to avoid breaking unattended updates. The mitigation set comes with documentation for administrators and a deeper technical view" * 'x86-mds-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits) x86/speculation/mds: Fix documentation typo Documentation: Correct the possible MDS sysfs values x86/mds: Add MDSUM variant to the MDS documentation x86/speculation/mds: Add 'mitigations=' support for MDS x86/speculation/mds: Print SMT vulnerable on MSBDS with mitigations off x86/speculation/mds: Fix comment x86/speculation/mds: Add SMT warning message x86/speculation: Move arch_smt_update() call to after mitigation decisions x86/speculation/mds: Add mds=full,nosmt cmdline option Documentation: Add MDS vulnerability documentation Documentation: Move L1TF to separate directory x86/speculation/mds: Add mitigation mode VMWERV x86/speculation/mds: Add sysfs reporting for MDS x86/speculation/mds: Add mitigation control for MDS x86/speculation/mds: Conditionally clear CPU buffers on idle entry x86/kvm/vmx: Add MDS protection when L1D Flush is not active x86/speculation/mds: Clear CPU buffers on exit to user x86/speculation/mds: Add mds_clear_cpu_buffers() x86/kvm: Expose X86_FEATURE_MD_CLEAR to guests x86/speculation/mds: Add BUG_MSBDS_ONLY ...
2019-05-10x86: intel_epb: Take CONFIG_PM into accountRafael J. Wysocki1-1/+21
Commit b9c273babce7 ("PM / arch: x86: MSR_IA32_ENERGY_PERF_BIAS sysfs interface") caused kernels built with CONFIG_PM unset to crash on systems supporting the Performance and Energy Bias Hint (EPB), because it attempts to add files to sysfs directories that don't exist on those systems. Prevent that from happening by taking CONFIG_PM into account so that the code depending on it is not compiled at all when it is not set. Fixes: b9c273babce7 ("PM / arch: x86: MSR_IA32_ENERGY_PERF_BIAS sysfs interface") Reported-by: Ido Schimmel <[email protected]> Tested-by: Ido Schimmel <[email protected]> Signed-off-by: Rafael J. Wysocki <[email protected]> Acked-by: Ingo Molnar <[email protected]>