summaryrefslogtreecommitdiff
path: root/arch/x86/kernel
AgeCommit message (Collapse)AuthorFilesLines
2019-07-04Merge tag 'v5.1.16' into dev-5.1dev-5.1Joel Stanley3-25/+36
This is the 5.1.16 stable release Signed-off-by: Joel Stanley <joel@jms.id.au>
2019-07-03x86/resctrl: Prevent possible overrun during bitmap operationsReinette Chatre1-19/+16
commit 32f010deab575199df4ebe7b6aec20c17bb7eccd upstream. 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 <reinette.chatre@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: stable <stable@vger.kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/58c9b6081fd9bf599af0dfc01a6fdd335768efef.1560975645.git.reinette.chatre@intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-03x86/microcode: Fix the microcode load on CPU hotplug for realThomas Gleixner1-5/+10
commit 5423f5ce5ca410b3646f355279e4e937d452e622 upstream. 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 <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: stable@vger.kernel.org Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1906182228350.1766@nanos.tec.linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-03x86/speculation: Allow guests to use SSBD even if host does notAlejandro Jimenez1-1/+10
commit c1f7fec1eb6a2c86d01bc22afce772c743451d88 upstream. The bits set in x86_spec_ctrl_mask are used to calculate the guest's value of SPEC_CTRL that is written to the MSR before VMENTRY, and control which mitigations the guest can enable. In the case of SSBD, unless the host has enabled SSBD always on mode (by passing "spec_store_bypass_disable=on" in the kernel parameters), the SSBD bit is not set in the mask and the guest can not properly enable the SSBD always on mitigation mode. This has been confirmed by running the SSBD PoC on a guest using the SSBD always on mitigation mode (booted with kernel parameter "spec_store_bypass_disable=on"), and verifying that the guest is vulnerable unless the host is also using SSBD always on mode. In addition, the guest OS incorrectly reports the SSB vulnerability as mitigated. Always set the SSBD bit in x86_spec_ctrl_mask when the host CPU supports it, allowing the guest to use SSBD whether or not the host has chosen to enable the mitigation in any of its modes. Fixes: be6fcb5478e9 ("x86/bugs: Rework spec_ctrl base and mask logic") Signed-off-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Reviewed-by: Mark Kanda <mark.kanda@oracle.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Cc: bp@alien8.de Cc: rkrcmar@redhat.com Cc: kvm@vger.kernel.org Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/1560187210-11054-1-git-send-email-alejandro.j.jimenez@oracle.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-02treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152Thomas Gleixner6-30/+6
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 <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> (cherry picked from commit 2874c5fd284268364ece81a7bd936f3c8168e567) Signed-off-by: Joel Stanley <joel@jms.id.au>
2019-06-25x86/resctrl: Don't stop walking closids when a locksetup group is foundJames Morse1-1/+1
commit 87d3aa28f345bea77c396855fa5d5fec4c24461f upstream. 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 <james.morse@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Reinette Chatre <reinette.chatre@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: H Peter Avin <hpa@zytor.com> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20190603172531.178830-1-james.morse@arm.com [Dropped comment due to lack of space] Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-22x86/CPU/AMD: Don't force the CPB cap when running under a hypervisorFrank van der Linden1-2/+5
[ Upstream commit 2ac44ab608705948564791ce1d15d43ba81a1e38 ] 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 <fllinden@amazon.com> Acked-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@alien8.de Cc: jiaxun.yang@flygoat.com 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 <mingo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-06-19x86/resctrl: Prevent NULL pointer dereference when local MBM is disabledPrarit Bhargava1-0/+3
commit c7563e62a6d720aa3b068e26ddffab5f0df29263 upstream. 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 <prarit@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Reinette Chatre <reinette.chatre@intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20190610171544.13474-1-prarit@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19x86/microcode, cpuhotplug: Add a microcode loader CPU hotplug callbackBorislav Petkov1-1/+1
commit 78f4e932f7760d965fb1569025d1576ab77557c5 upstream. 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 <promarbler14@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> Cc: x86@kernel.org Link: https://bugzilla.kernel.org/show_bug.cgi?id=203637 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-09x86/kprobes: Set instruction page as executableNadav Amit1-4/+20
[ Upstream commit 7298e24f904224fa79eb8fd7e0fbd78950ccf2db ] Set the page as executable after allocation. This patch is a preparatory patch for a following patch that makes module allocated pages non-executable. While at it, do some small cleanup of what appears to be unnecessary masking. Signed-off-by: Nadav Amit <namit@vmware.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <akpm@linux-foundation.org> Cc: <ard.biesheuvel@linaro.org> Cc: <deneen.t.dock@intel.com> Cc: <kernel-hardening@lists.openwall.com> Cc: <kristen@linux.intel.com> Cc: <linux_dti@icloud.com> Cc: <will.deacon@arm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190426001143.4983-11-namit@vmware.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-06-09Revert "x86/build: Move _etext to actual end of .text"Greg Kroah-Hartman1-3/+3
This reverts commit 392bef709659abea614abfe53cf228e7a59876a4. It seems to cause lots of problems when using the gold linker, and no one really needs this at the moment, so just revert it from the stable trees. Cc: Sami Tolvanen <samitolvanen@google.com> Reported-by: Kees Cook <keescook@chromium.org> Cc: Borislav Petkov <bp@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Reported-by: Alec Ari <neotheuser@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-09x86/ima: Check EFI_RUNTIME_SERVICES before usingScott Wood1-0/+5
commit 558b523d46289f111d53d7c42211069063be5985 upstream. Checking efi_enabled(EFI_BOOT) is not sufficient to ensure that EFI runtime services are available, e.g. if efi=noruntime is used. Without this, I get an oops on a PREEMPT_RT kernel where efi=noruntime is the default. Fixes: 399574c64eaf94e8 ("x86/ima: retry detecting secure boot mode") Cc: stable@vger.kernel.org (linux-5.0) Signed-off-by: Scott Wood <swood@redhat.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-31x86/CPU/hygon: Fix phys_proc_id calculation logic for multi-die processorsPu Wen1-0/+5
[ Upstream commit e0ceeae708cebf22c990c3d703a4ca187dc837f5 ] The Hygon family 18h multi-die processor platform supports 1, 2 or 4-Dies per socket. The topology looks like this: System View (with 1-Die 2-Socket): |------------| ------ ----- SOCKET0 | D0 | | D1 | SOCKET1 ------ ----- System View (with 2-Die 2-socket): -------------------- | -------------|------ | | | | ------------ ------------ SOCKET0 | D1 -- D0 | | D3 -- D2 | SOCKET1 ------------ ------------ System View (with 4-Die 2-Socket) : -------------------- | -------------|------ | | | | ------------ ------------ | D1 -- D0 | | D7 -- D6 | | | \/ | | | | \/ | | SOCKET0 | | /\ | | | | /\ | | SOCKET1 | D2 -- D3 | | D4 -- D5 | ------------ ------------ | | | | ------|------------| | -------------------- Currently phys_proc_id = initial_apicid >> bits calculates the physical processor ID from the initial_apicid by shifting *bits*. However, this does not work for 1-Die and 2-Die 2-socket systems. According to document [1] section 2.1.11.1, the bits is the value of CPUID_Fn80000008_ECX[12:15]. The possible values are 4, 5 or 6 which mean: 4 - 1 die 5 - 2 dies 6 - 3/4 dies. Hygon programs the initial ApicId the same way as AMD. The ApicId is read from CPUID_Fn00000001_EBX (see section 2.1.11.1 of referrence [1]) and the definition is as below (see section 2.1.10.2.1.3 of [1]): ------------------------------------------------- Bit | 6 | 5 4 | 3 | 2 1 0 | |-----------|---------|--------|----------------| IDs | Socket ID | Node ID | CCX ID | Core/Thread ID | ------------------------------------------------- So for 3/4-Die configurations, the bits variable is 6, which is the same as the ApicID definition field. For 1-Die and 2-Die configurations, bits is 4 or 5, which will cause the right shifted result to not be exactly the value of socket ID. However, the socket ID should be obtained from ApicId[6]. To fix the problem and match the ApicID field definition, set the shift bits to 6 for all Hygon family 18h multi-die CPUs. Because AMD doesn't have 2-Socket systems with 1-Die/2-Die processors (see reference [2]), this doesn't need to be changed on the AMD side but only for Hygon. References: [1] https://www.amd.com/system/files/TechDocs/54945_PPR_Family_17h_Models_00h-0Fh.pdf [2] https://www.amd.com/en/products/specifications/processors [bp: heavily massage commit message. ] Signed-off-by: Pu Wen <puwen@hygon.cn> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thomas Lendacky <Thomas.Lendacky@amd.com> Cc: Yazen Ghannam <yazen.ghannam@amd.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/1553355740-19999-1-git-send-email-puwen@hygon.cn Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-31x86/mce: Handle varying MCA bank countsYazen Ghannam2-22/+14
[ Upstream commit 006c077041dc73b9490fffc4c6af5befe0687110 ] Linux reads MCG_CAP[Count] to find the number of MCA banks visible to a CPU. Currently, this number is the same for all CPUs and a warning is shown if there is a difference. The number of banks is overwritten with the MCG_CAP[Count] value of each following CPU that boots. According to the Intel SDM and AMD APM, the MCG_CAP[Count] value gives the number of banks that are available to a "processor implementation". The AMD BKDGs/PPRs further clarify that this value is per core. This value has historically been the same for every core in the system, but that is not an architectural requirement. Future AMD systems may have different MCG_CAP[Count] values per core, so the assumption that all CPUs will have the same MCG_CAP[Count] value will no longer be valid. Also, the first CPU to boot will allocate the struct mce_banks[] array using the number of banks based on its MCG_CAP[Count] value. The machine check handler and other functions use the global number of banks to iterate and index into the mce_banks[] array. So it's possible to use an out-of-bounds index on an asymmetric system where a following CPU sees a MCG_CAP[Count] value greater than its predecessors. Thus, allocate the mce_banks[] array to the maximum number of banks. This will avoid the potential out-of-bounds index since the value of mca_cfg.banks is capped to MAX_NR_BANKS. Set the value of mca_cfg.banks equal to the max of the previous value and the value for the current CPU. This way mca_cfg.banks will always represent the max number of banks detected on any CPU in the system. This will ensure that all CPUs will access all the banks that are visible to them. A CPU that can access fewer than the max number of banks will find the registers of the extra banks to be read-as-zero. Furthermore, print the resulting number of MCA banks in use. Do this in mcheck_late_init() so that the final value is printed after all CPUs have been initialized. Finally, get bank count from target CPU when doing injection with mce-inject module. [ bp: Remove out-of-bounds example, passify and cleanup commit message. ] Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: linux-edac <linux-edac@vger.kernel.org> Cc: Pu Wen <puwen@hygon.cn> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20180727214009.78289-1-Yazen.Ghannam@amd.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-31x86/mce: Fix machine_check_poll() tests for error typesTony Luck1-7/+37
[ Upstream commit f19501aa07f18268ab14f458b51c1c6b7f72a134 ] There has been a lurking "TBD" in the machine check poll routine ever since it was first split out from the machine check handler. The potential issue is that the poll routine may have just begun a read from the STATUS register in a machine check bank when the hardware logs an error in that bank and signals a machine check. That race used to be pretty small back when machine checks were broadcast, but the addition of local machine check means that the poll code could continue running and clear the error from the bank before the local machine check handler on another CPU gets around to reading it. Fix the code to be sure to only process errors that need to be processed in the poll code, leaving other logged errors alone for the machine check handler to find and process. [ bp: Massage a bit and flip the "== 0" check to the usual !(..) test. ] Fixes: b79109c3bbcf ("x86, mce: separate correct machine check poller and fatal exception handler") Fixes: ed7290d0ee8f ("x86, mce: implement new status bits") Reported-by: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Ashok Raj <ashok.raj@intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: linux-edac <linux-edac@vger.kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86-ml <x86@kernel.org> Cc: Yazen Ghannam <Yazen.Ghannam@amd.com> Link: https://lkml.kernel.org/r/20190312170938.GA23035@agluck-desk Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-31x86/uaccess, signal: Fix AC=1 bloatPeter Zijlstra1-12/+17
[ Upstream commit 88e4718275c1bddca6f61f300688b4553dc8584b ] Occasionally GCC is less agressive with inlining and the following is observed: arch/x86/kernel/signal.o: warning: objtool: restore_sigcontext()+0x3cc: call to force_valid_ss.isra.5() with UACCESS enabled arch/x86/kernel/signal.o: warning: objtool: do_signal()+0x384: call to frame_uc_flags.isra.0() with UACCESS enabled Cure this by moving this code out of the AC=1 region, since it really isn't needed for the user access. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-31x86/microcode: Fix the ancient deprecated microcode loading methodBorislav Petkov1-1/+2
[ Upstream commit 24613a04ad1c0588c10f4b5403ca60a73d164051 ] Commit 2613f36ed965 ("x86/microcode: Attempt late loading only when new microcode is present") added the new define UCODE_NEW to denote that an update should happen only when newer microcode (than installed on the system) has been found. But it missed adjusting that for the old /dev/cpu/microcode loading interface. Fix it. Fixes: 2613f36ed965 ("x86/microcode: Attempt late loading only when new microcode is present") Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Jann Horn <jannh@google.com> Link: https://lkml.kernel.org/r/20190405133010.24249-3-bp@alien8.de Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-31x86/irq/64: Limit IST stack overflow check to #DB stackThomas Gleixner1-5/+14
[ Upstream commit 7dbcf2b0b770eeb803a416ee8dcbef78e6389d40 ] Commit 37fe6a42b343 ("x86: Check stack overflow in detail") added a broad check for the full exception stack area, i.e. it considers the full exception stack area as valid. That's wrong in two aspects: 1) It does not check the individual areas one by one 2) #DF, NMI and #MCE are not enabling interrupts which means that a regular device interrupt cannot happen in their context. In fact if a device interrupt hits one of those IST stacks that's a bug because some code path enabled interrupts while handling the exception. Limit the check to the #DB stack and consider all other IST stacks as 'overflow' or invalid. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Mitsuo Hayasaka <mitsuo.hayasaka.hu@hitachi.com> Cc: Nicolai Stange <nstange@suse.de> Cc: Sean Christopherson <sean.j.christopherson@intel.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190414160143.682135110@linutronix.de Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-31x86/build: Move _etext to actual end of .textKees Cook1-3/+3
[ Upstream commit 392bef709659abea614abfe53cf228e7a59876a4 ] When building x86 with Clang LTO and CFI, CFI jump regions are automatically added to the end of the .text section late in linking. As a result, the _etext position was being labelled before the appended jump regions, causing confusion about where the boundaries of the executable region actually are in the running kernel, and broke at least the fault injection code. This moves the _etext mark to outside (and immediately after) the .text area, as it already the case on other architectures (e.g. arm64, arm). Reported-and-tested-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Borislav Petkov <bp@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20190423183827.GA4012@beast Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-31x86/modules: Avoid breaking W^X while loading modulesNadav Amit2-8/+22
[ Upstream commit f2c65fb3221adc6b73b0549fc7ba892022db9797 ] When modules and BPF filters are loaded, there is a time window in which some memory is both writable and executable. An attacker that has already found another vulnerability (e.g., a dangling pointer) might be able to exploit this behavior to overwrite kernel code. Prevent having writable executable PTEs in this stage. In addition, avoiding having W+X mappings can also slightly simplify the patching of modules code on initialization (e.g., by alternatives and static-key), as would be done in the next patch. This was actually the main motivation for this patch. To avoid having W+X mappings, set them initially as RW (NX) and after they are set as RO set them as X as well. Setting them as executable is done as a separate step to avoid one core in which the old PTE is cached (hence writable), and another which sees the updated PTE (executable), which would break the W^X protection. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Suggested-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Nadav Amit <namit@vmware.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <akpm@linux-foundation.org> Cc: <ard.biesheuvel@linaro.org> Cc: <deneen.t.dock@intel.com> Cc: <kernel-hardening@lists.openwall.com> Cc: <kristen@linux.intel.com> Cc: <linux_dti@icloud.com> Cc: <will.deacon@arm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jessica Yu <jeyu@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Rik van Riel <riel@surriel.com> Link: https://lkml.kernel.org/r/20190426001143.4983-12-namit@vmware.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-31x86/ftrace: Set trampoline pages as executableNadav Amit1-0/+8
[ Upstream commit 3c0dab44e22782359a0a706cbce72de99a22aa75 ] Since alloc_module() will not set the pages as executable soon, set ftrace trampoline pages as executable after they are allocated. For the time being, do not change ftrace to use the text_poke() interface. As a result, ftrace still breaks W^X. Signed-off-by: Nadav Amit <namit@vmware.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: <akpm@linux-foundation.org> Cc: <ard.biesheuvel@linaro.org> Cc: <deneen.t.dock@intel.com> Cc: <kernel-hardening@lists.openwall.com> Cc: <kristen@linux.intel.com> Cc: <linux_dti@icloud.com> Cc: <will.deacon@arm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190426001143.4983-10-namit@vmware.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-25ftrace/x86_64: Emulate call function while updating in breakpoint handlerPeter Zijlstra1-5/+27
commit 9e298e8604088a600d8100a111a532a9d342af09 upstream. Nicolai Stange discovered[1] that if live kernel patching is enabled, and the function tracer started tracing the same function that was patched, the conversion of the fentry call site during the translation of going from calling the live kernel patch trampoline to the iterator trampoline, would have as slight window where it didn't call anything. As live kernel patching depends on ftrace to always call its code (to prevent the function being traced from being called, as it will redirect it). This small window would allow the old buggy function to be called, and this can cause undesirable results. Nicolai submitted new patches[2] but these were controversial. As this is similar to the static call emulation issues that came up a while ago[3]. But after some debate[4][5] adding a gap in the stack when entering the breakpoint handler allows for pushing the return address onto the stack to easily emulate a call. [1] http://lkml.kernel.org/r/20180726104029.7736-1-nstange@suse.de [2] http://lkml.kernel.org/r/20190427100639.15074-1-nstange@suse.de [3] http://lkml.kernel.org/r/3cf04e113d71c9f8e4be95fb84a510f085aa4afa.1541711457.git.jpoimboe@redhat.com [4] http://lkml.kernel.org/r/CAHk-=wh5OpheSU8Em_Q3Hg8qw_JtoijxOdPtHru6d+5K8TWM=A@mail.gmail.com [5] http://lkml.kernel.org/r/CAHk-=wjvQxY4DvPrJ6haPgAa6b906h=MwZXO6G8OtiTGe=N7_w@mail.gmail.com [ Live kernel patching is not implemented on x86_32, thus the emulate calls are only for x86_64. ] Cc: Andy Lutomirski <luto@kernel.org> Cc: Nicolai Stange <nstange@suse.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: the arch/x86 maintainers <x86@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Petr Mladek <pmladek@suse.com> Cc: Joe Lawrence <joe.lawrence@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Mimi Zohar <zohar@linux.ibm.com> Cc: Juergen Gross <jgross@suse.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Nayna Jain <nayna@linux.ibm.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: "open list:KERNEL SELFTEST FRAMEWORK" <linux-kselftest@vger.kernel.org> Cc: stable@vger.kernel.org Fixes: b700e7f03df5 ("livepatch: kernel: add support for live patching") Tested-by: Nicolai Stange <nstange@suse.de> Reviewed-by: Nicolai Stange <nstange@suse.de> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> [ Changed to only implement emulated calls for x86_64 ] Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-22x86/MCE/AMD: Don't report L1 BTB MCA errors on some family 17h modelsYazen Ghannam3-13/+48
commit 71a84402b93e5fbd8f817f40059c137e10171788 upstream. AMD family 17h Models 10h-2Fh may report a high number of L1 BTB MCA errors under certain conditions. The errors are benign and can safely be ignored. However, the high error rate may cause the MCA threshold counter to overflow causing a high rate of thresholding interrupts. In addition, users may see the errors reported through the AMD MCE decoder module, even with the interrupt disabled, due to MCA polling. Clear the "Counter Present" bit in the Instruction Fetch bank's MCA_MISC0 register. This will prevent enabling MCA thresholding on this bank which will prevent the high interrupt rate due to this error. Define an AMD-specific function to filter these errors from the MCE event pool so that they don't get reported during early boot. Rename filter function in EDAC/mce_amd to avoid a naming conflict, while at it. [ bp: Move function prototype to the internal header and massage/cleanup, fix typos. ] Reported-by: Rafał Miłecki <rafal@milecki.pl> Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "clemej@gmail.com" <clemej@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Morse <james.morse@arm.com> Cc: Kees Cook <keescook@chromium.org> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Pu Wen <puwen@hygon.cn> Cc: Qiuxu Zhuo <qiuxu.zhuo@intel.com> Cc: Shirish S <Shirish.S@amd.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: linux-edac <linux-edac@vger.kernel.org> Cc: x86-ml <x86@kernel.org> Cc: <stable@vger.kernel.org> # 5.0.x: c95b323dcd35: x86/MCE/AMD: Turn off MC4_MISC thresholding on all family 0x15 models Cc: <stable@vger.kernel.org> # 5.0.x: 30aa3d26edb0: x86/MCE/AMD: Carve out the MC4_MISC thresholding quirk Cc: <stable@vger.kernel.org> # 5.0.x: 9308fd407455: x86/MCE: Group AMD function prototypes in <asm/mce.h> Cc: <stable@vger.kernel.org> # 5.0.x Link: https://lkml.kernel.org/r/20190325163410.171021-2-Yazen.Ghannam@amd.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-22x86/MCE: Add an MCE-record filtering functionYazen Ghannam3-0/+11
commit 45d4b7b9cb88526f6d5bd4c03efab88d75d10e4f upstream. Some systems may report spurious MCA errors. In general, spurious MCA errors may be disabled by clearing a particular bit in MCA_CTL. However, clearing a bit in MCA_CTL may not be recommended for some errors, so the only option is to ignore them. An MCA error is printed and handled after it has been added to the MCE event pool. So an MCA error can be ignored by not adding it to that pool in the first place. Add such a filtering function. [ bp: Move function prototype to the internal header and massage. ] Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: "clemej@gmail.com" <clemej@gmail.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Pu Wen <puwen@hygon.cn> Cc: Qiuxu Zhuo <qiuxu.zhuo@intel.com> Cc: "rafal@milecki.pl" <rafal@milecki.pl> Cc: Shirish S <Shirish.S@amd.com> Cc: <stable@vger.kernel.org> # 5.0.x Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190325163410.171021-1-Yazen.Ghannam@amd.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-22sched/x86: Save [ER]FLAGS on context switchPeter Zijlstra2-0/+15
commit 6690e86be83ac75832e461c141055b5d601c0a6d upstream. Effectively reverts commit: 2c7577a75837 ("sched/x86_64: Don't save flags on context switch") Specifically because SMAP uses FLAGS.AC which invalidates the claim that the kernel has clean flags. In particular; while preemption from interrupt return is fine (the IRET frame on the exception stack contains FLAGS) it breaks any code that does synchonous scheduling, including preempt_enable(). This has become a significant issue ever since commit: 5b24a7a2aa20 ("Add 'unsafe' user access functions for batched accesses") provided for means of having 'normal' C code between STAC / CLAC, exposing the FLAGS.AC state. So far this hasn't led to trouble, however fix it before it comes apart. Reported-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable@kernel.org Fixes: 5b24a7a2aa20 ("Add 'unsafe' user access functions for batched accesses") Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-22x86/speculation/mds: Revert CPU buffer clear on double fault exitAndy Lutomirski1-8/+0
commit 88640e1dcd089879530a49a8d212d1814678dfe7 upstream. The double fault ESPFIX path doesn't return to user mode at all -- it returns back to the kernel by simulating a #GP fault. prepare_exit_to_usermode() will run on the way out of general_protection before running user code. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@suse.de> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jon Masters <jcm@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Fixes: 04dcbdb80578 ("x86/speculation/mds: Clear CPU buffers on exit to user") Link: http://lkml.kernel.org/r/ac97612445c0a44ee10374f6ea79c222fe22a5c4.1557865329.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14x86/speculation/mds: Add 'mitigations=' support for MDSJosh Poimboeuf1-2/+3
commit 5c14068f87d04adc73ba3f41c2a303d3c3d1fa12 upstream Add MDS to the new 'mitigations=' cmdline option. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14x86/speculation: Support 'mitigations=' cmdline optionJosh Poimboeuf1-2/+9
commit d68be4c4d31295ff6ae34a8ddfaa4c1a8ff42812 upstream Configure x86 runtime CPU speculation bug mitigations in accordance with the 'mitigations=' cmdline option. This affects Meltdown, Spectre v2, Speculative Store Bypass, and L1TF. The default behavior is unchanged. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Jiri Kosina <jkosina@suse.cz> (on x86) Reviewed-by: Jiri Kosina <jkosina@suse.cz> Cc: Borislav Petkov <bp@alien8.de> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Jiri Kosina <jikos@kernel.org> Cc: Waiman Long <longman@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Jon Masters <jcm@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: linuxppc-dev@lists.ozlabs.org Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux-s390@vger.kernel.org Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-arch@vger.kernel.org Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Tyler Hicks <tyhicks@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Steven Price <steven.price@arm.com> Cc: Phil Auld <pauld@redhat.com> Link: https://lkml.kernel.org/r/6616d0ae169308516cfdf5216bedd169f8a8291b.1555085500.git.jpoimboe@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14x86/speculation/mds: Print SMT vulnerable on MSBDS with mitigations offKonrad Rzeszutek Wilk1-1/+2
commit e2c3c94788b08891dcf3dbe608f9880523ecd71b upstream This code is only for CPUs which are affected by MSBDS, but are *not* affected by the other two MDS issues. For such CPUs, enabling the mds_idle_clear mitigation is enough to mitigate SMT. However if user boots with 'mds=off' and still has SMT enabled, we should not report that SMT is mitigated: $cat /sys//devices/system/cpu/vulnerabilities/mds Vulnerable; SMT mitigated But rather: Vulnerable; SMT vulnerable Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Tyler Hicks <tyhicks@canonical.com> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lkml.kernel.org/r/20190412215118.294906495@localhost.localdomain Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14x86/speculation/mds: Fix commentBoris Ostrovsky1-1/+1
commit cae5ec342645746d617dd420d206e1588d47768a upstream s/L1TF/MDS/ Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Tyler Hicks <tyhicks@canonical.com> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14x86/speculation/mds: Add SMT warning messageJosh Poimboeuf1-0/+8
commit 39226ef02bfb43248b7db12a4fdccb39d95318e3 upstream MDS is vulnerable with SMT. Make that clear with a one-time printk whenever SMT first gets enabled. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Tyler Hicks <tyhicks@canonical.com> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14x86/speculation: Move arch_smt_update() call to after mitigation decisionsJosh Poimboeuf1-3/+2
commit 7c3658b20194a5b3209a143f63bc9c643c6a3ae2 upstream arch_smt_update() now has a dependency on both Spectre v2 and MDS mitigations. Move its initial call to after all the mitigation decisions have been made. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Tyler Hicks <tyhicks@canonical.com> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14x86/speculation/mds: Add mds=full,nosmt cmdline optionJosh Poimboeuf1-0/+10
commit d71eb0ce109a124b0fa714832823b9452f2762cf upstream Add the mds=full,nosmt cmdline option. This is like mds=full, but with SMT disabled if the CPU is vulnerable. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Tyler Hicks <tyhicks@canonical.com> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14Documentation: Move L1TF to separate directoryThomas Gleixner1-1/+1
commit 65fd4cb65b2dad97feb8330b6690445910b56d6a upstream Move L!TF to a separate directory so the MDS stuff can be added at the side. Otherwise the all hardware vulnerabilites have their own top level entry. Should have done that right away. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Jon Masters <jcm@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14x86/speculation/mds: Add mitigation mode VMWERVThomas Gleixner1-6/+12
commit 22dd8365088b6403630b82423cf906491859b65e upstream In virtualized environments it can happen that the host has the microcode update which utilizes the VERW instruction to clear CPU buffers, but the hypervisor is not yet updated to expose the X86_FEATURE_MD_CLEAR CPUID bit to guests. Introduce an internal mitigation mode VMWERV which enables the invocation of the CPU buffer clearing even if X86_FEATURE_MD_CLEAR is not set. If the system has no updated microcode this results in a pointless execution of the VERW instruction wasting a few CPU cycles. If the microcode is updated, but not exposed to a guest then the CPU buffers will be cleared. That said: Virtual Machines Will Eventually Receive Vaccine Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14x86/speculation/mds: Add sysfs reporting for MDSThomas Gleixner1-0/+25
commit 8a4b06d391b0a42a373808979b5028f5c84d9c6a upstream Add the sysfs reporting file for MDS. It exposes the vulnerability and mitigation state similar to the existing files for the other speculative hardware vulnerabilities. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14x86/speculation/mds: Add mitigation control for MDSThomas Gleixner1-0/+70
commit bc1241700acd82ec69fde98c5763ce51086269f8 upstream Now that the mitigations are in place, add a command line parameter to control the mitigation, a mitigation selector function and a SMT update mechanism. This is the minimal straight forward initial implementation which just provides an always on/off mode. The command line parameter is: mds=[full|off] This is consistent with the existing mitigations for other speculative hardware vulnerabilities. The idle invocation is dynamically updated according to the SMT state of the system similar to the dynamic update of the STIBP mitigation. The idle mitigation is limited to CPUs which are only affected by MSBDS and not any other variant, because the other variants cannot be mitigated on SMT enabled systems. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14x86/speculation/mds: Conditionally clear CPU buffers on idle entryThomas Gleixner1-0/+3
commit 07f07f55a29cb705e221eda7894dd67ab81ef343 upstream Add a static key which controls the invocation of the CPU buffer clear mechanism on idle entry. This is independent of other MDS mitigations because the idle entry invocation to mitigate the potential leakage due to store buffer repartitioning is only necessary on SMT systems. Add the actual invocations to the different halt/mwait variants which covers all usage sites. mwaitx is not patched as it's not available on Intel CPUs. The buffer clear is only invoked before entering the C-State to prevent that stale data from the idling CPU is spilled to the Hyper-Thread sibling after the Store buffer got repartitioned and all entries are available to the non idle sibling. When coming out of idle the store buffer is partitioned again so each sibling has half of it available. Now CPU which returned from idle could be speculatively exposed to contents of the sibling, but the buffers are flushed either on exit to user space or on VMENTER. When later on conditional buffer clearing is implemented on top of this, then there is no action required either because before returning to user space the context switch will set the condition flag which causes a flush on the return to user path. Note, that the buffer clearing on idle is only sensible on CPUs which are solely affected by MSBDS and not any other variant of MDS because the other MDS variants cannot be mitigated when SMT is enabled, so the buffer clearing on idle would be a window dressing exercise. This intentionally does not handle the case in the acpi/processor_idle driver which uses the legacy IO port interface for C-State transitions for two reasons: - The acpi/processor_idle driver was replaced by the intel_idle driver almost a decade ago. Anything Nehalem upwards supports it and defaults to that new driver. - The legacy IO port interface is likely to be used on older and therefore unaffected CPUs or on systems which do not receive microcode updates anymore, so there is no point in adding that. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14x86/kvm/vmx: Add MDS protection when L1D Flush is not activeThomas Gleixner1-0/+1
commit 650b68a0622f933444a6d66936abb3103029413b upstream CPUs which are affected by L1TF and MDS mitigate MDS with the L1D Flush on VMENTER when updated microcode is installed. If a CPU is not affected by L1TF or if the L1D Flush is not in use, then MDS mitigation needs to be invoked explicitly. For these cases, follow the host mitigation state and invoke the MDS mitigation before VMENTER. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14x86/speculation/mds: Clear CPU buffers on exit to userThomas Gleixner3-0/+15
commit 04dcbdb8057827b043b3c71aa397c4c63e67d086 upstream Add a static key which controls the invocation of the CPU buffer clear mechanism on exit to user space and add the call into prepare_exit_to_usermode() and do_nmi() right before actually returning. Add documentation which kernel to user space transition this covers and explain why some corner cases are not mitigated. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14x86/speculation/mds: Add BUG_MSBDS_ONLYThomas Gleixner1-8/+12
commit e261f209c3666e842fd645a1e31f001c3a26def9 upstream This bug bit is set on CPUs which are only affected by Microarchitectural Store Buffer Data Sampling (MSBDS) and not by any other MDS variant. This is important because the Store Buffers are partitioned between Hyper-Threads so cross thread forwarding is not possible. But if a thread enters or exits a sleep state the store buffer is repartitioned which can expose data from one thread to the other. This transition can be mitigated. That means that for CPUs which are only affected by MSBDS SMT can be enabled, if the CPU is not affected by other SMT sensitive vulnerabilities, e.g. L1TF. The XEON PHI variants fall into that category. Also the Silvermont/Airmont ATOMs, but for them it's not really relevant as they do not support SMT, but mark them for completeness sake. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14x86/speculation/mds: Add basic bug infrastructure for MDSAndi Kleen1-9/+16
commit ed5194c2732c8084af9fd159c146ea92bf137128 upstream Microarchitectural Data Sampling (MDS), is a class of side channel attacks on internal buffers in Intel CPUs. The variants are: - Microarchitectural Store Buffer Data Sampling (MSBDS) (CVE-2018-12126) - Microarchitectural Fill Buffer Data Sampling (MFBDS) (CVE-2018-12130) - Microarchitectural Load Port Data Sampling (MLPDS) (CVE-2018-12127) MSBDS leaks Store Buffer Entries which can be speculatively forwarded to a dependent load (store-to-load forwarding) as an optimization. The forward can also happen to a faulting or assisting load operation for a different memory address, which can be exploited under certain conditions. Store buffers are partitioned between Hyper-Threads so cross thread forwarding is not possible. But if a thread enters or exits a sleep state the store buffer is repartitioned which can expose data from one thread to the other. MFBDS leaks Fill Buffer Entries. Fill buffers are used internally to manage L1 miss situations and to hold data which is returned or sent in response to a memory or I/O operation. Fill buffers can forward data to a load operation and also write data to the cache. When the fill buffer is deallocated it can retain the stale data of the preceding operations which can then be forwarded to a faulting or assisting load operation, which can be exploited under certain conditions. Fill buffers are shared between Hyper-Threads so cross thread leakage is possible. MLDPS leaks Load Port Data. Load ports are used to perform load operations from memory or I/O. The received data is then forwarded to the register file or a subsequent operation. In some implementations the Load Port can contain stale data from a previous operation which can be forwarded to faulting or assisting loads under certain conditions, which again can be exploited eventually. Load ports are shared between Hyper-Threads so cross thread leakage is possible. All variants have the same mitigation for single CPU thread case (SMT off), so the kernel can treat them as one MDS issue. Add the basic infrastructure to detect if the current CPU is affected by MDS. [ tglx: Rewrote changelog ] Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14x86/speculation: Consolidate CPU whitelistsThomas Gleixner1-50/+60
commit 36ad35131adacc29b328b9c8b6277a8bf0d6fd5d upstream The CPU vulnerability whitelists have some overlap and there are more whitelists coming along. Use the driver_data field in the x86_cpu_id struct to denote the whitelisted vulnerabilities and combine all whitelists into one. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-20Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds1-2/+46
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Misc fixes: - various tooling fixes - kretprobe fixes - kprobes annotation fixes - kprobes error checking fix - fix the default events for AMD Family 17h CPUs - PEBS fix - AUX record fix - address filtering fix" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/kprobes: Avoid kretprobe recursion bug kprobes: Mark ftrace mcount handler functions nokprobe x86/kprobes: Verify stack frame on kretprobe perf/x86/amd: Add event map for AMD Family 17h perf bpf: Return NULL when RB tree lookup fails in perf_env__find_btf() perf tools: Fix map reference counting perf evlist: Fix side band thread draining perf tools: Check maps for bpf programs perf bpf: Return NULL when RB tree lookup fails in perf_env__find_bpf_prog_info() tools include uapi: Sync sound/asound.h copy perf top: Always sample time to satisfy needs of use of ordered queuing perf evsel: Use hweight64() instead of hweight_long(attr.sample_regs_user) tools lib traceevent: Fix missing equality check for strcmp perf stat: Disable DIR_FORMAT feature for 'perf stat record' perf scripts python: export-to-sqlite.py: Fix use of parent_id in calls_view perf header: Fix lock/unlock imbalances when processing BPF/BTF info perf/x86: Fix incorrect PEBS_REGS perf/ring_buffer: Fix AUX record suppression perf/core: Fix the address filtering fix kprobes: Fix error check when reusing optimized probes
2019-04-19x86/cpu/intel: Lower the "ENERGY_PERF_BIAS: Set to normal" message's log ↵Hans de Goede1-2/+2
priority The "ENERGY_PERF_BIAS: Set to 'normal', was 'performance'" message triggers on pretty much every Intel machine. The purpose of log messages with a warning level is to notify the user of something which potentially is a problem, or at least somewhat unexpected. This message clearly does not match those criteria, so lower its log priority from warning to info. Signed-off-by: Hans de Goede <hdegoede@redhat.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> Link: http://lkml.kernel.org/r/20181230172715.17469-1-hdegoede@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-19x86/cpu/bugs: Use __initconst for 'const' init dataAndi Kleen1-3/+3
Some of the recently added const tables use __initdata which causes section attribute conflicts. Use __initconst instead. Fixes: fa1202ef2243 ("x86/speculation: Add command line control") Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20190330004743.29541-9-andi@firstfloor.org
2019-04-19x86/kprobes: Avoid kretprobe recursion bugMasami Hiramatsu1-2/+20
Avoid kretprobe recursion loop bg by setting a dummy kprobes to current_kprobe per-CPU variable. This bug has been introduced with the asm-coded trampoline code, since previously it used another kprobe for hooking the function return placeholder (which only has a nop) and trampoline handler was called from that kprobe. This revives the old lost kprobe again. With this fix, we don't see deadlock anymore. And you can see that all inner-called kretprobe are skipped. event_1 235 0 event_2 19375 19612 The 1st column is recorded count and the 2nd is missed count. Above shows (event_1 rec) + (event_2 rec) ~= (event_2 missed) (some difference are here because the counter is racy) Reported-by: Andrea Righi <righi.andrea@gmail.com> Tested-by: Andrea Righi <righi.andrea@gmail.com> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Fixes: c9becf58d935 ("[PATCH] kretprobe: kretprobe-booster") Link: http://lkml.kernel.org/r/155094064889.6137.972160690963039.stgit@devbox Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-19x86/kprobes: Verify stack frame on kretprobeMasami Hiramatsu1-0/+26
Verify the stack frame pointer on kretprobe trampoline handler, If the stack frame pointer does not match, it skips the wrong entry and tries to find correct one. This can happen if user puts the kretprobe on the function which can be used in the path of ftrace user-function call. Such functions should not be probed, so this adds a warning message that reports which function should be blacklisted. Tested-by: Andrea Righi <righi.andrea@gmail.com> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/155094059185.6137.15527904013362842072.stgit@devbox Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-16x86/reboot, efi: Use EFI reboot for Acer TravelMate X514-51TJian-Hong Pan1-0/+21
Upon reboot, the Acer TravelMate X514-51T laptop appears to complete the shutdown process, but then it hangs in BIOS POST with a black screen. The problem is intermittent - at some points it has appeared related to Secure Boot settings or different kernel builds, but ultimately we have not been able to identify the exact conditions that trigger the issue to come and go. Besides, the EFI mode cannot be disabled in the BIOS of this model. However, after extensive testing, we observe that using the EFI reboot method reliably avoids the issue in all cases. So add a boot time quirk to use EFI reboot on such systems. Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=203119 Signed-off-by: Jian-Hong Pan <jian-hong@endlessm.com> Signed-off-by: Daniel Drake <drake@endlessm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Cc: linux@endlessm.com Link: http://lkml.kernel.org/r/20190412080152.3718-1-jian-hong@endlessm.com [ Fix !CONFIG_EFI build failure, clarify the code and the changelog a bit. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-16x86/build/lto: Fix truncated .bss with -fdata-sectionsSami Tolvanen1-1/+1
With CONFIG_LD_DEAD_CODE_DATA_ELIMINATION=y, we compile the kernel with -fdata-sections, which also splits the .bss section. The new section, with a new .bss.* name, which pattern gets missed by the main x86 linker script which only expects the '.bss' name. This results in the discarding of the second part and a too small, truncated .bss section and an unhappy, non-working kernel. Use the common BSS_MAIN macro in the linker script to properly capture and merge all the generated BSS sections. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20190415164956.124067-1-samitolvanen@google.com [ Extended the changelog. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>