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2018-10-14x86/entry: Add some paranoid entry/exit CR3 handling commentsDave Hansen
Andi Kleen was just asking me about the NMI CR3 handling and why we restore it unconditionally. I was *sure* we had documented it well. We did not. Add some documentation. We have common entry code where the CR3 value is stashed, but three places in two big code paths where we restore it. I put bulk of the comments in this common path and then refer to it from the other spots. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: luto@kernel.org Cc: bp@alien8.de Cc: "H. Peter Anvin" <hpa@zytor.come Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Link: https://lkml.kernel.org/r/20181012232118.3EAAE77B@viggo.jf.intel.com
2018-10-14x86/percpu: Fix this_cpu_read()Peter Zijlstra
Eric reported that a sequence count loop using this_cpu_read() got optimized out. This is wrong, this_cpu_read() must imply READ_ONCE() because the interface is IRQ-safe, therefore an interrupt can have changed the per-cpu value. Fixes: 7c3576d261ce ("[PATCH] i386: Convert PDA into the percpu section") Reported-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Eric Dumazet <edumazet@google.com> Cc: hpa@zytor.com Cc: eric.dumazet@gmail.com Cc: bp@alien8.de Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181011104019.748208519@infradead.org
2018-10-14x86/tsc: Force inlining of cyc2ns bitsPeter Zijlstra
Looking at the asm for native_sched_clock() I noticed we don't inline enough. Mostly caused by sharing code with cyc2ns_read_begin(), which we didn't used to do. So mark all that __force_inline to make it DTRT. Fixes: 59eaef78bfea ("x86/tsc: Remodel cyc2ns to use seqcount_latch()") Reported-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: hpa@zytor.com Cc: eric.dumazet@gmail.com Cc: bp@alien8.de Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181011104019.695196158@infradead.org
2018-10-14Merge tag 'libnvdimm-fixes-4.19-rc8' of ↵Greg Kroah-Hartman
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Dan writes: "libnvdimm/dax 4.19-rc8 * Fix a livelock in dax_layout_busy_page() present since v4.18. The lockup triggers when truncating an actively mapped huge page out of a mapping pinned for direct-I/O. * Fix mprotect() clobbers of _PAGE_DEVMAP. Broken since v4.5 mprotect() clears this flag that is needed to communicate the liveness of device pages to the get_user_pages() path." * tag 'libnvdimm-fixes-4.19-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: mm: Preserve _PAGE_DEVMAP across mprotect() calls filesystem-dax: Fix dax_layout_busy_page() livelock
2018-10-13Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmGreg Kroah-Hartman
Paolo writes: "KVM fixes for 4.19-rc8 Leftover bugfixes." * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: vmx: hyper-v: don't pass EPT configuration info to vmx_hv_remote_flush_tlb() KVM: x86: support CONFIG_KVM_AMD=y with CONFIG_CRYPTO_DEV_CCP_DD=m ARM: KVM: Correctly order SGI register entries in the cp15 array
2018-10-13KVM: nVMX: Do not flush TLB on L1<->L2 transitions if L1 uses VPID and EPTLiran Alon
If L1 uses VPID, it expects TLB to not be flushed on L1<->L2 transitions. However, code currently flushes TLB nonetheless if we didn't allocate a vpid02 for L2. As in this case, vmcs02->vpid == vmcs01->vpid == vmx->vpid. But, if L1 uses EPT, TLB entires populated by L2 are tagged with EPTP02 while TLB entries populated by L1 are tagged with EPTP01. Therefore, we can also avoid TLB flush if L1 uses VPID and EPT. Reviewed-by: Mihai Carabas <mihai.carabas@oracle.com> Reviewed-by: Darren Kenny <darren.kenny@oracle.com> Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com> Signed-off-by: Liran Alon <liran.alon@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-13KVM: nVMX: Flush linear and combined mappings on VPID02 related flushesLiran Alon
All VPID12s used on a given L1 vCPU is translated to a single VPID02 (vmx->nested.vpid02 or vmx->vpid). Therefore, on L1->L2 VMEntry, we need to invalidate linear and combined mappings tagged by VPID02 in case L1 uses VPID and vmcs12->vpid was changed since last L1->L2 VMEntry. However, current code invalidates the wrong mappings as it calls __vmx_flush_tlb() with invalidate_gpa parameter set to true which will result in invalidating combined and guest-physical mappings tagged with active EPTP which is EPTP01. Similarly, INVVPID emulation have the exact same issue. Fix both issues by just setting invalidate_gpa parameter to false which will result in invalidating linear and combined mappings tagged with given VPID02 as required. Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com> Reviewed-by: Mark Kanda <mark.kanda@oracle.com> Signed-off-by: Liran Alon <liran.alon@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-13KVM: nVMX: Use correct VPID02 when emulating L1 INVVPIDLiran Alon
In case L0 didn't allocate vmx->nested.vpid02 for L2, vmcs02->vpid is set to vmx->vpid. Consider this case when emulating L1 INVVPID in L0. Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com> Reviewed-by: Mark Kanda <mark.kanda@oracle.com> Signed-off-by: Liran Alon <liran.alon@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-13KVM: nVMX: Flush TLB entries tagged by dest EPTP on L1<->L2 transitionsLiran Alon
If L1 and L2 share VPID (because L1 don't use VPID or we haven't allocated a vpid02), we need to flush TLB on L1<->L2 transitions. Before this patch, this TLB flushing was done by vmx_flush_tlb(). If L0 use EPT, this will translate into INVEPT(active_eptp); However, if L1 use EPT, in L1->L2 VMEntry, active EPTP is EPTP01 but TLB entries populated by L2 are tagged with EPTP02. Therefore we should delay vmx_flush_tlb() until active_eptp is EPTP02. To achieve this, instead of directly calling vmx_flush_tlb() we request it to be called by KVM_REQ_TLB_FLUSH which is evaluated after KVM_REQ_LOAD_CR3 which sets the active_eptp to EPTP02 as required. Similarly, on L2->L1 VMExit, active EPTP is EPTP02 but TLB entries populated by L1 are tagged with EPTP01 and therefore we should delay vmx_flush_tlb() until active_eptp is EPTP01. Reviewed-by: Mihai Carabas <mihai.carabas@oracle.com> Reviewed-by: Darren Kenny <darren.kenny@oracle.com> Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com> Signed-off-by: Liran Alon <liran.alon@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-13KVM: vmx: rename KVM_GUEST_CR0_MASK tp KVM_VM_CR0_ALWAYS_OFFSean Christopherson
The KVM_GUEST_CR0_MASK macro tracks CR0 bits that are forced to zero by the VMX architecture, i.e. CR0.{NW,CD} must always be zero in the hardware CR0 post-VMXON. Rename the macro to clarify its purpose, be consistent with KVM_VM_CR0_ALWAYS_ON and avoid confusion with the CR0_GUEST_HOST_MASK field. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-13KVM: vmx: hyper-v: don't pass EPT configuration info to ↵Vitaly Kuznetsov
vmx_hv_remote_flush_tlb() I'm observing random crashes in multi-vCPU L2 guests running on KVM on Hyper-V. I bisected the issue to the commit 877ad952be3d ("KVM: vmx: Add tlb_remote_flush callback support"). Hyper-V TLFS states: "AddressSpace specifies an address space ID (an EPT PML4 table pointer)" So apparently, Hyper-V doesn't expect us to pass naked EPTP, only PML4 pointer should be used. Strip off EPT configuration information before calling into vmx_hv_remote_flush_tlb(). Fixes: 877ad952be3d ("KVM: vmx: Add tlb_remote_flush callback support") Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-12x86/cpu: Drop pointless static qualifier in punit_dev_state_show()YueHaibing
There is no need to have the 'struct dentry *dev_state' variable static since new value always be assigned before use it. Signed-off-by: YueHaibing <yuehaibing@huawei.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kernel-janitors@vger.kernel.org Link: http://lkml.kernel.org/r/1539340822-117563-1-git-send-email-yuehaibing@huawei.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-10x86: ptrace: Add function argument access APIMasami Hiramatsu
Add regs_get_argument() which returns N th argument of the function call. Note that this chooses most probably assignment, in some case it can be incorrect (e.g. passing data structure or floating point etc.) This is expected to be called from kprobes or ftrace with regs where the top of stack is the return address. Link: http://lkml.kernel.org/r/152465885737.26224.2822487520472783854.stgit@devbox Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-10-10Merge branches 'arm/renesas', 'arm/smmu', 'ppc/pamu', 'x86/vt-d', 'x86/amd' ↵Joerg Roedel
and 'core' into next
2018-10-10x86/mm: Do not warn about PCI BIOS W+X mappingsThomas Gleixner
PCI BIOS requires the BIOS area 0x0A0000-0x0FFFFFF to be mapped W+X for various legacy reasons. When CONFIG_DEBUG_WX is enabled, this triggers the WX warning, but this is misleading because the mapping is required and is not a result of an accidental oversight. Prevent the full warning when PCI BIOS is enabled and the detected WX mapping is in the BIOS area. Just emit a pr_warn() which denotes the fact. This is partially duplicating the info which the PCI BIOS code emits when it maps the area as executable, but that info is not in the context of the WX checking output. Remove the extra %p printout in the WARN_ONCE() while at it. %pS is enough. Reported-by: Paul Menzel <pmenzel@molgen.mpg.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Borislav Petkov <bp@suse.de> Cc: Joerg Roedel <joro@8bytes.org> Cc: Kees Cook <keescook@chromium.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1810082151160.2455@nanos.tec.linutronix.de
2018-10-10x86/acpi, x86/boot: Take RSDP address for boot params if availableJuergen Gross
In case the RSDP address in struct boot_params is specified don't try to find the table by searching, but take the address directly as set by the boot loader. Signed-off-by: Juergen Gross <jgross@suse.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Jia Zhang <qianyue.zj@alibaba-inc.com> Cc: Len Brown <len.brown@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: Pavel Tatashin <pasha.tatashin@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: boris.ostrovsky@oracle.com Cc: linux-kernel@vger.kernel.org Cc: linux-pm@vger.kernel.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/20181010061456.22238-4-jgross@suse.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-10x86/boot: Add ACPI RSDP address to setup_headerJuergen Gross
Xen PVH guests receive the address of the RSDP table from Xen. In order to support booting a Xen PVH guest via Grub2 using the standard x86 boot entry we need a way for Grub2 to pass the RSDP address to the kernel. For this purpose expand the struct setup_header to hold the physical address of the RSDP address. Being zero means it isn't specified and has to be located the legacy way (searching through low memory or EBDA). While documenting the new setup_header layout and protocol version 2.14 add the missing documentation of protocol version 2.13. There are Grub2 versions in several distros with a downstream patch violating the boot protocol by writing past the end of setup_header. This requires another update of the boot protocol to enable the kernel to distinguish between a specified RSDP address and one filled with garbage by such a broken Grub2. From protocol 2.14 on Grub2 will write the version it is supporting (but never a higher value than found to be supported by the kernel) ored with 0x8000 to the version field of setup_header. This enables the kernel to know up to which field Grub2 has written information to. All fields after that are supposed to be clobbered. Signed-off-by: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: boris.ostrovsky@oracle.com Cc: bp@alien8.de Cc: corbet@lwn.net Cc: linux-doc@vger.kernel.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/20181010061456.22238-3-jgross@suse.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-10x86/xen: Fix boot loader version reported for PVH guestsJuergen Gross
The boot loader version reported via sysfs is wrong in case of the kernel being booted via the Xen PVH boot entry. it should be 2.12 (0x020c), but it is reported to be 2.18 (0x0212). As the current way to set the version is error prone use the more readable variant (2 << 8) | 12. Signed-off-by: Juergen Gross <jgross@suse.com> Cc: <stable@vger.kernel.org> # 4.12 Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: boris.ostrovsky@oracle.com Cc: bp@alien8.de Cc: corbet@lwn.net Cc: linux-doc@vger.kernel.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/20181010061456.22238-2-jgross@suse.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-10x86/defconfig: Enable CONFIG_USB_XHCI_HCD=yAdam Borowski
A spanking new machine I just got has all but one USB ports wired as 3.0. Booting defconfig resulted in no keyboard or mouse, which was pretty uncool. Let's enable that -- USB3 is ubiquitous rather than an oddity. As 'y' not 'm' -- recovering from initrd problems needs a keyboard. Also add it to the 32-bit defconfig. Signed-off-by: Adam Borowski <kilobyte@angband.pl> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-usb@vger.kernel.org Link: http://lkml.kernel.org/r/20181009062803.4332-1-kilobyte@angband.pl Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-09mm: Preserve _PAGE_DEVMAP across mprotect() callsJan Kara
Currently _PAGE_DEVMAP bit is not preserved in mprotect(2) calls. As a result we will see warnings such as: BUG: Bad page map in process JobWrk0013 pte:800001803875ea25 pmd:7624381067 addr:00007f0930720000 vm_flags:280000f9 anon_vma: (null) mapping:ffff97f2384056f0 index:0 file:457-000000fe00000030-00000009-000000ca-00000001_2001.fileblock fault:xfs_filemap_fault [xfs] mmap:xfs_file_mmap [xfs] readpage: (null) CPU: 3 PID: 15848 Comm: JobWrk0013 Tainted: G W 4.12.14-2.g7573215-default #1 SLE12-SP4 (unreleased) Hardware name: Intel Corporation S2600WFD/S2600WFD, BIOS SE5C620.86B.01.00.0833.051120182255 05/11/2018 Call Trace: dump_stack+0x5a/0x75 print_bad_pte+0x217/0x2c0 ? enqueue_task_fair+0x76/0x9f0 _vm_normal_page+0xe5/0x100 zap_pte_range+0x148/0x740 unmap_page_range+0x39a/0x4b0 unmap_vmas+0x42/0x90 unmap_region+0x99/0xf0 ? vma_gap_callbacks_rotate+0x1a/0x20 do_munmap+0x255/0x3a0 vm_munmap+0x54/0x80 SyS_munmap+0x1d/0x30 do_syscall_64+0x74/0x150 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 ... when mprotect(2) gets used on DAX mappings. Also there is a wide variety of other failures that can result from the missing _PAGE_DEVMAP flag when the area gets used by get_user_pages() later. Fix the problem by including _PAGE_DEVMAP in a set of flags that get preserved by mprotect(2). Fixes: 69660fd797c3 ("x86, mm: introduce _PAGE_DEVMAP") Fixes: ebd31197931d ("powerpc/mm: Add devmap support for ppc64") Cc: <stable@vger.kernel.org> Signed-off-by: Jan Kara <jack@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2018-10-09KVM: x86: support CONFIG_KVM_AMD=y with CONFIG_CRYPTO_DEV_CCP_DD=mPaolo Bonzini
SEV requires access to the AMD cryptographic device APIs, and this does not work when KVM is builtin and the crypto driver is a module. Actually the Kconfig conditions for CONFIG_KVM_AMD_SEV try to disable SEV in that case, but it does not work because the actual crypto calls are not culled, only sev_hardware_setup() is. This patch adds two CONFIG_KVM_AMD_SEV checks that gate all the remaining SEV code; it fixes this particular configuration, and drops 5 KiB of code when CONFIG_KVM_AMD_SEV=n. Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-09x86/kexec: Correct KEXEC_BACKUP_SRC_END off-by-one errorBjorn Helgaas
The only use of KEXEC_BACKUP_SRC_END is as an argument to walk_system_ram_res(): int crash_load_segments(struct kimage *image) { ... walk_system_ram_res(KEXEC_BACKUP_SRC_START, KEXEC_BACKUP_SRC_END, image, determine_backup_region); walk_system_ram_res() expects "start, end" arguments that are inclusive, i.e., the range to be walked includes both the start and end addresses. KEXEC_BACKUP_SRC_END was previously defined as (640 * 1024UL), which is the first address *past* the desired 0-640KB range. Define KEXEC_BACKUP_SRC_END as (640 * 1024UL - 1) so the KEXEC_BACKUP_SRC region is [0-0x9ffff], not [0-0xa0000]. Fixes: dd5f726076cc ("kexec: support for kexec on panic using new system call") Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> CC: "H. Peter Anvin" <hpa@zytor.com> CC: Andrew Morton <akpm@linux-foundation.org> CC: Brijesh Singh <brijesh.singh@amd.com> CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org> CC: Ingo Molnar <mingo@redhat.com> CC: Lianbo Jiang <lijiang@redhat.com> CC: Takashi Iwai <tiwai@suse.de> CC: Thomas Gleixner <tglx@linutronix.de> CC: Tom Lendacky <thomas.lendacky@amd.com> CC: Vivek Goyal <vgoyal@redhat.com> CC: baiyaowei@cmss.chinamobile.com CC: bhe@redhat.com CC: dan.j.williams@intel.com CC: dyoung@redhat.com CC: kexec@lists.infradead.org Link: http://lkml.kernel.org/r/153805811578.1157.6948388946904655969.stgit@bhelgaas-glaptop.roam.corp.google.com
2018-10-09x86/mm: Remove spurious fault pkey checkDave Hansen
Spurious faults only ever occur in the kernel's address space. They are also constrained specifically to faults with one of these error codes: X86_PF_WRITE | X86_PF_PROT X86_PF_INSTR | X86_PF_PROT So, it's never even possible to reach spurious_kernel_fault_check() with X86_PF_PK set. In addition, the kernel's address space never has pages with user-mode protections. Protection Keys are only enforced on pages with user-mode protection. This gives us lots of reasons to not check for protection keys in our sprurious kernel fault handling. But, let's also add some warnings to ensure that these assumptions about protection keys hold true. Cc: x86@kernel.org Cc: Jann Horn <jannh@google.com> Cc: Sean Christopherson <sean.j.christopherson@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: http://lkml.kernel.org/r/20180928160231.243A0D6A@viggo.jf.intel.com
2018-10-09x86/mm/vsyscall: Consider vsyscall page part of user address spaceDave Hansen
The vsyscall page is weird. It is in what is traditionally part of the kernel address space. But, it has user permissions and we handle faults on it like we would on a user page: interrupts on. Right now, we handle vsyscall emulation in the "bad_area" code, which is used for both user-address-space and kernel-address-space faults. Move the handling to the user-address-space code *only* and ensure we get there by "excluding" the vsyscall page from the kernel address space via a check in fault_in_kernel_space(). Since the fault_in_kernel_space() check is used on 32-bit, also add a 64-bit check to make it clear we only use this path on 64-bit. Also move the unlikely() to be in is_vsyscall_vaddr() itself. This helps clean up the kernel fault handling path by removing a case that can happen in normal[1] operation. (Yeah, yeah, we can argue about the vsyscall page being "normal" or not.) This also makes sanity checks easier, like the "we never take pkey faults in the kernel address space" check in the next patch. Cc: x86@kernel.org Cc: Jann Horn <jannh@google.com> Cc: Sean Christopherson <sean.j.christopherson@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: http://lkml.kernel.org/r/20180928160230.6E9336EE@viggo.jf.intel.com
2018-10-09x86/mm: Add vsyscall address helperDave Hansen
We will shortly be using this check in two locations. Put it in a helper before we do so. Let's also insert PAGE_MASK instead of the open-coded ~0xfff. It is easier to read and also more obviously correct considering the implicit type conversion that has to happen when it is not an implicit 'unsigned long'. Cc: x86@kernel.org Cc: Jann Horn <jannh@google.com> Cc: Sean Christopherson <sean.j.christopherson@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: http://lkml.kernel.org/r/20180928160228.C593509B@viggo.jf.intel.com
2018-10-09x86/mm: Fix exception table commentsDave Hansen
The comments here are wrong. They are too absolute about where faults can occur when running in the kernel. The comments are also a bit hard to match up with the code. Trim down the comments, and make them more precise. Also add a comment explaining why we are doing the bad_area_nosemaphore() path here. Cc: x86@kernel.org Cc: Jann Horn <jannh@google.com> Cc: Sean Christopherson <sean.j.christopherson@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: http://lkml.kernel.org/r/20180928160227.077DDD7A@viggo.jf.intel.com
2018-10-09x86/mm: Add clarifying comments for user addr spaceDave Hansen
The SMAP and Reserved checking do not have nice comments. Add some to clarify and make it match everything else. Cc: x86@kernel.org Cc: Jann Horn <jannh@google.com> Cc: Sean Christopherson <sean.j.christopherson@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: http://lkml.kernel.org/r/20180928160225.FFD44B8D@viggo.jf.intel.com
2018-10-09x86/mm: Break out user address space handlingDave Hansen
The last patch broke out kernel address space handing into its own helper. Now, do the same for user address space handling. Cc: x86@kernel.org Cc: Jann Horn <jannh@google.com> Cc: Sean Christopherson <sean.j.christopherson@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: http://lkml.kernel.org/r/20180928160223.9C4F6440@viggo.jf.intel.com
2018-10-09x86/mm: Break out kernel address space handlingDave Hansen
The page fault handler (__do_page_fault()) basically has two sections: one for handling faults in the kernel portion of the address space and another for faults in the user portion of the address space. But, these two parts don't stick out that well. Let's make that more clear from code separation and naming. Pull kernel fault handling into its own helper, and reflect that naming by renaming spurious_fault() -> spurious_kernel_fault(). Also, rewrite the vmalloc() handling comment a bit. It was a bit stale and also glossed over the reserved bit handling. Cc: x86@kernel.org Cc: Jann Horn <jannh@google.com> Cc: Sean Christopherson <sean.j.christopherson@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: http://lkml.kernel.org/r/20180928160222.401F4E10@viggo.jf.intel.com
2018-10-09x86/mm: Clarify hardware vs. software "error_code"Dave Hansen
We pass around a variable called "error_code" all around the page fault code. Sounds simple enough, especially since "error_code" looks like it exactly matches the values that the hardware gives us on the stack to report the page fault error code (PFEC in SDM parlance). But, that's not how it works. For part of the page fault handler, "error_code" does exactly match PFEC. But, during later parts, it diverges and starts to mean something a bit different. Give it two names for its two jobs. The place it diverges is also really screwy. It's only in a spot where the hardware tells us we have kernel-mode access that occurred while we were in usermode accessing user-controlled address space. Add a warning in there. Cc: x86@kernel.org Cc: Jann Horn <jannh@google.com> Cc: Sean Christopherson <sean.j.christopherson@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: http://lkml.kernel.org/r/20180928160220.4A2272C9@viggo.jf.intel.com
2018-10-09x86/mm/tlb: Make lazy TLB mode lazierRik van Riel
Lazy TLB mode can result in an idle CPU being woken up by a TLB flush, when all it really needs to do is reload %CR3 at the next context switch, assuming no page table pages got freed. Memory ordering is used to prevent race conditions between switch_mm_irqs_off, which checks whether .tlb_gen changed, and the TLB invalidation code, which increments .tlb_gen whenever page table entries get invalidated. The atomic increment in inc_mm_tlb_gen is its own barrier; the context switch code adds an explicit barrier between reading tlbstate.is_lazy and next->context.tlb_gen. CPUs in lazy TLB mode remain part of the mm_cpumask(mm), both because that allows TLB flush IPIs to be sent at page table freeing time, and because the cache line bouncing on the mm_cpumask(mm) was responsible for about half the CPU use in switch_mm_irqs_off(). We can change native_flush_tlb_others() without touching other (paravirt) implementations of flush_tlb_others() because we'll be flushing less. The existing implementations flush more and are therefore still correct. Cc: npiggin@gmail.com Cc: mingo@kernel.org Cc: will.deacon@arm.com Cc: kernel-team@fb.com Cc: luto@kernel.org Cc: hpa@zytor.com Tested-by: Song Liu <songliubraving@fb.com> Signed-off-by: Rik van Riel <riel@surriel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: http://lkml.kernel.org/r/20180926035844.1420-8-riel@surriel.com
2018-10-09x86/mm/tlb: Add freed_tables element to flush_tlb_infoRik van Riel
Pass the information on to native_flush_tlb_others. No functional changes. Cc: npiggin@gmail.com Cc: mingo@kernel.org Cc: will.deacon@arm.com Cc: songliubraving@fb.com Cc: kernel-team@fb.com Cc: hpa@zytor.com Cc: luto@kernel.org Signed-off-by: Rik van Riel <riel@surriel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: http://lkml.kernel.org/r/20180926035844.1420-7-riel@surriel.com
2018-10-09x86/mm/tlb: Add freed_tables argument to flush_tlb_mm_rangeRik van Riel
Add an argument to flush_tlb_mm_range to indicate whether page tables are about to be freed after this TLB flush. This allows for an optimization of flush_tlb_mm_range to skip CPUs in lazy TLB mode. No functional changes. Cc: npiggin@gmail.com Cc: mingo@kernel.org Cc: will.deacon@arm.com Cc: songliubraving@fb.com Cc: kernel-team@fb.com Cc: luto@kernel.org Cc: hpa@zytor.com Signed-off-by: Rik van Riel <riel@surriel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: http://lkml.kernel.org/r/20180926035844.1420-6-riel@surriel.com
2018-10-09x86/mm/tlb: Restructure switch_mm_irqs_off()Rik van Riel
Move some code that will be needed for the lazy -> !lazy state transition when a lazy TLB CPU has gotten out of date. No functional changes, since the if (real_prev == next) branch always returns. (cherry picked from commit 61d0beb5796ab11f7f3bf38cb2eccc6579aaa70b) Cc: npiggin@gmail.com Cc: efault@gmx.de Cc: will.deacon@arm.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: songliubraving@fb.com Cc: kernel-team@fb.com Cc: hpa@zytor.com Suggested-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Rik van Riel <riel@surriel.com> Acked-by: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: http://lkml.kernel.org/r/20180716190337.26133-4-riel@surriel.com
2018-10-09x86/mm/tlb: Always use lazy TLB modeRik van Riel
On most workloads, the number of context switches far exceeds the number of TLB flushes sent. Optimizing the context switches, by always using lazy TLB mode, speeds up those workloads. This patch results in about a 1% reduction in CPU use on a two socket Broadwell system running a memcache like workload. Cc: npiggin@gmail.com Cc: efault@gmx.de Cc: will.deacon@arm.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kernel-team@fb.com Cc: hpa@zytor.com Cc: luto@kernel.org Tested-by: Song Liu <songliubraving@fb.com> Signed-off-by: Rik van Riel <riel@surriel.com> (cherry picked from commit 95b0e6357d3e4e05349668940d7ff8f3b7e7e11e) Acked-by: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: http://lkml.kernel.org/r/20180716190337.26133-7-riel@surriel.com
2018-10-09x86/mm: Page size aware flush_tlb_mm_range()Peter Zijlstra
Use the new tlb_get_unmap_shift() to determine the stride of the INVLPG loop. Cc: Nick Piggin <npiggin@gmail.com> Cc: Will Deacon <will.deacon@arm.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2018-10-09x86/hyperv: Enable PV qspinlock for Hyper-VYi Sun
Implement the required wait and kick callbacks to support PV spinlocks in Hyper-V guests. [ tglx: Document the requirement for disabling interrupts in the wait() callback. Remove goto and unnecessary includes. Add prototype for hv_vcpu_is_preempted(). Adapted to pending paravirt changes. ] Signed-off-by: Yi Sun <yi.y.sun@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Juergen Gross <jgross@suse.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Michael Kelley (EOSG) <Michael.H.Kelley@microsoft.com> Cc: chao.p.peng@intel.com Cc: chao.gao@intel.com Cc: isaku.yamahata@intel.com Cc: tianyu.lan@microsoft.com Link: https://lkml.kernel.org/r/1538987374-51217-3-git-send-email-yi.y.sun@linux.intel.com
2018-10-09x86/hyperv: Add GUEST_IDLE_MSR supportYi Sun
Hyper-V may expose a HV_X64_MSR_GUEST_IDLE MSR via HYPERV_CPUID_FEATURES. Reading this MSR triggers the host to transition the guest vCPU into an idle state. This state can be exited via an IPI even if the read in the guest happened from an interrupt disabled section. Signed-off-by: Yi Sun <yi.y.sun@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Cc: chao.p.peng@intel.com Cc: chao.gao@intel.com Cc: isaku.yamahata@intel.com Cc: tianyu.lan@microsoft.com Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Link: https://lkml.kernel.org/r/1538028104-114050-2-git-send-email-yi.y.sun@linux.intel.com
2018-10-09x86/mm: Avoid VLA in pgd_alloc()Kees Cook
Arnd Bergmann reported that turning on -Wvla found a new (unintended) VLA usage: arch/x86/mm/pgtable.c: In function 'pgd_alloc': include/linux/build_bug.h:29:45: error: ISO C90 forbids variable length array 'u_pmds' [-Werror=vla] arch/x86/mm/pgtable.c:190:34: note: in expansion of macro 'static_cpu_has' #define PREALLOCATED_USER_PMDS (static_cpu_has(X86_FEATURE_PTI) ? \ ^~~~~~~~~~~~~~ arch/x86/mm/pgtable.c:431:16: note: in expansion of macro 'PREALLOCATED_USER_PMDS' pmd_t *u_pmds[PREALLOCATED_USER_PMDS]; ^~~~~~~~~~~~~~~~~~~~~~ Use the actual size of the array that is used for X86_FEATURE_PTI, which is known at build time, instead of the variable size. [ mingo: Squashed original fix with followup fix to avoid bisection breakage, wrote new changelog. ] Reported-by: Arnd Bergmann <arnd@arndb.de> Original-written-by: Arnd Bergmann <arnd@arndb.de> Reported-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hpe.com> Fixes: 1be3f247c288 ("x86/mm: Avoid VLA in pgd_alloc()") Link: http://lkml.kernel.org/r/20181008235434.GA35035@beast Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-09x86/intel_rdt: Fix initial allocation to consider CDPReinette Chatre
When a new resource group is created it is initialized with a default allocation that considers which portions of cache are currently available for sharing across all resource groups or which portions of cache are currently unused. If a CDP allocation forms part of a resource group that is in exclusive mode then it should be ensured that no new allocation overlaps with any resource that shares the underlying hardware. The current initial allocation does not take this sharing of hardware into account and a new allocation in a resource that shares the same hardware would affect the exclusive resource group. Fix this by considering the allocation of a peer RDT domain - a RDT domain sharing the same hardware - as part of the test to determine which portion of cache is in use and available for use. Fixes: 95f0b77efa57 ("x86/intel_rdt: Initialize new resource group with sane defaults") Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Fenghua Yu <fenghua.yu@intel.com> Cc: tony.luck@intel.com Cc: jithu.joseph@intel.com Cc: gavin.hindman@intel.com Cc: dave.hansen@intel.com Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/b1f7ec08b1695be067de416a4128466d49684317.1538603665.git.reinette.chatre@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-09x86/intel_rdt: CBM overlap should also check for overlap with CDP peerReinette Chatre
The CBM overlap test is used to manage the allocations of RDT resources where overlap is possible between resource groups. When a resource group is in exclusive mode then there should be no overlap between resource groups. The current overlap test only considers overlap between the same resources, for example, that usage of a RDT_RESOURCE_L2DATA resource in one resource group does not overlap with usage of a RDT_RESOURCE_L2DATA resource in another resource group. The problem with this is that it allows overlap between a RDT_RESOURCE_L2DATA resource in one resource group with a RDT_RESOURCE_L2CODE resource in another resource group - even if both resource groups are in exclusive mode. This is a problem because even though these appear to be different resources they end up sharing the same underlying hardware and thus does not fulfill the user's request for exclusive use of hardware resources. Fix this by including the CDP peer (if there is one) in every CBM overlap test. This does not impact the overlap between resources within the same exclusive resource group that is allowed. Fixes: 49f7b4efa110 ("x86/intel_rdt: Enable setting of exclusive mode") Reported-by: Jithu Joseph <jithu.joseph@intel.com> Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Jithu Joseph <jithu.joseph@intel.com> Acked-by: Fenghua Yu <fenghua.yu@intel.com> Cc: tony.luck@intel.com Cc: gavin.hindman@intel.com Cc: dave.hansen@intel.com Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/e538b7f56f7ca15963dce2e00ac3be8edb8a68e1.1538603665.git.reinette.chatre@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-09x86/intel_rdt: Introduce utility to obtain CDP peerReinette Chatre
Introduce a utility that, when provided with a RDT resource and an instance of this RDT resource (a RDT domain), would return pointers to the RDT resource and RDT domain that share the same hardware. This is specific to the CDP resources that share the same hardware. For example, if a pointer to the RDT_RESOURCE_L2DATA resource (struct rdt_resource) and a pointer to an instance of this resource (struct rdt_domain) is provided, then it will return a pointer to the RDT_RESOURCE_L2CODE resource as well as the specific instance that shares the same hardware as the provided rdt_domain. This utility is created in support of the "exclusive" resource group mode where overlap of resource allocation between resource groups need to be avoided. The overlap test need to consider not just the matching resources, but also the resources that share the same hardware. Temporarily mark it as unused in support of patch testing to avoid compile warnings until it is used. Fixes: 49f7b4efa110 ("x86/intel_rdt: Enable setting of exclusive mode") Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Jithu Joseph <jithu.joseph@intel.com> Acked-by: Fenghua Yu <fenghua.yu@intel.com> Cc: tony.luck@intel.com Cc: gavin.hindman@intel.com Cc: dave.hansen@intel.com Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/9b4bc4d59ba2e903b6a3eb17e16ef41a8e7b7c3e.1538603665.git.reinette.chatre@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-09Merge branch 'x86/urgent' into x86/cache, to pick up dependent fixIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-09x86/intel_rdt: Fix out-of-bounds memory access in CBM testsReinette Chatre
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 bitmap_intersects() 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 is confirmed with a KASAN test that reports: BUG: KASAN: stack-out-of-bounds in __bitmap_intersects+0xa2/0x100 and BUG: KASAN: stack-out-of-bounds in __bitmap_weight+0x58/0x90 Fix this by moving any CBM provided to a bitmap operation needing BITS_PER_LONG to an 'unsigned long' variable. [ tglx: Changed related function arguments to unsigned long and got rid of the _cbm extra step ] Fixes: 72d505056604 ("x86/intel_rdt: Add utilities to test pseudo-locked region possibility") Fixes: 49f7b4efa110 ("x86/intel_rdt: Enable setting of exclusive mode") Fixes: d9b48c86eb38 ("x86/intel_rdt: Display resource groups' allocations' size in bytes") Fixes: 95f0b77efa57 ("x86/intel_rdt: Initialize new resource group with sane defaults") Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: fenghua.yu@intel.com Cc: tony.luck@intel.com Cc: gavin.hindman@intel.com Cc: jithu.joseph@intel.com Cc: dave.hansen@intel.com Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/69a428613a53f10e80594679ac726246020ff94f.1538686926.git.reinette.chatre@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-08x86/fsgsbase/64: Clean up various detailsIngo Molnar
So: - use 'extern' consistently for APIs - fix weird header guard - clarify code comments - reorder APIs by type Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Chang S. Bae <chang.seok.bae@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Markus T Metzger <markus.t.metzger@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Shankar <ravi.v.shankar@intel.com> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/1537312139-5580-2-git-send-email-chang.seok.bae@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-08x86/segments: Introduce the 'CPUNODE' naming to better document the segment ↵Ingo Molnar
limit CPU/node NR trick We have a special segment descriptor entry in the GDT, whose sole purpose is to encode the CPU and node numbers in its limit (size) field. There are user-space instructions that allow the reading of the limit field, which gives us a really fast way to read the CPU and node IDs from the vDSO for example. But the naming of related functionality does not make this clear, at all: VDSO_CPU_SIZE VDSO_CPU_MASK __CPU_NUMBER_SEG GDT_ENTRY_CPU_NUMBER vdso_encode_cpu_node vdso_read_cpu_node There's a number of problems: - The 'VDSO_CPU_SIZE' doesn't really make it clear that these are number of bits, nor does it make it clear which 'CPU' this refers to, i.e. that this is about a GDT entry whose limit encodes the CPU and node number. - Furthermore, the 'CPU_NUMBER' naming is actively misleading as well, because the segment limit encodes not just the CPU number but the node ID as well ... So use a better nomenclature all around: name everything related to this trick as 'CPUNODE', to make it clear that this is something special, and add _BITS to make it clear that these are number of bits, and propagate this to every affected name: VDSO_CPU_SIZE => VDSO_CPUNODE_BITS VDSO_CPU_MASK => VDSO_CPUNODE_MASK __CPU_NUMBER_SEG => __CPUNODE_SEG GDT_ENTRY_CPU_NUMBER => GDT_ENTRY_CPUNODE vdso_encode_cpu_node => vdso_encode_cpunode vdso_read_cpu_node => vdso_read_cpunode This, beyond being less confusing, also makes it easier to grep for all related functionality: $ git grep -i cpunode arch/x86 Also, while at it, fix "return is not a function" style sloppiness in vdso_encode_cpunode(). Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Chang S. Bae <chang.seok.bae@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Markus T Metzger <markus.t.metzger@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Shankar <ravi.v.shankar@intel.com> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/1537312139-5580-2-git-send-email-chang.seok.bae@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-08x86/vdso: Initialize the CPU/node NR segment descriptor earlierChang S. Bae
Currently the CPU/node NR segment descriptor (GDT_ENTRY_CPU_NUMBER) is initialized relatively late during CPU init, from the vCPU code, which has a number of disadvantages, such as hotplug CPU notifiers and SMP cross-calls. Instead just initialize it much earlier, directly in cpu_init(). This reduces complexity and increases robustness. [ mingo: Wrote new changelog. ] Suggested-by: H. Peter Anvin <hpa@zytor.com> Suggested-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Markus T Metzger <markus.t.metzger@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Shankar <ravi.v.shankar@intel.com> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1537312139-5580-9-git-send-email-chang.seok.bae@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-08x86/vdso: Introduce helper functions for CPU and node numberChang S. Bae
Clean up the CPU/node number related code a bit, to make it more apparent how we are encoding/extracting the CPU and node fields from the segment limit. No change in functionality intended. [ mingo: Wrote new changelog. ] Suggested-by: Andy Lutomirski <luto@kernel.org> Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Markus T Metzger <markus.t.metzger@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Shankar <ravi.v.shankar@intel.com> Cc: Rik van Riel <riel@surriel.com> Link: http://lkml.kernel.org/r/1537312139-5580-8-git-send-email-chang.seok.bae@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-08x86/segments/64: Rename the GDT PER_CPU entry to CPU_NUMBERChang S. Bae
The old 'per CPU' naming was misleading: 64-bit kernels don't use this GDT entry for per CPU data, but to store the CPU (and node) ID. [ mingo: Wrote new changelog. ] Suggested-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Markus T Metzger <markus.t.metzger@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Shankar <ravi.v.shankar@intel.com> Cc: Rik van Riel <riel@surriel.com> Link: http://lkml.kernel.org/r/1537312139-5580-7-git-send-email-chang.seok.bae@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-08x86/fsgsbase/64: Factor out FS/GS segment loading from __switch_to()Chang S. Bae
Instead of open coding the calls to load_seg_legacy(), introduce x86_fsgsbase_load() to load FS/GS segments. This makes it more explicit that this is part of FSGSBASE functionality, and the new helper can be updated when FSGSBASE instructions are enabled. [ mingo: Wrote new changelog. ] Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com> Reviewed-by: Andi Kleen <ak@linux.intel.com> Reviewed-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Markus T Metzger <markus.t.metzger@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Shankar <ravi.v.shankar@intel.com> Cc: Rik van Riel <riel@surriel.com> Link: http://lkml.kernel.org/r/1537312139-5580-6-git-send-email-chang.seok.bae@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>