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2019-09-23Merge tag 'v4.18.45' into v4.18/standard/baseBruce Ashfield
This is the 4.18.45 stable release # gpg: Signature made Sat 21 Sep 2019 12:20:15 PM EDT # gpg: using RSA key EBCE84042C07D1D6 # gpg: Can't check signature: No public key
2019-09-23Merge tag 'v4.18.44' into v4.18/standard/baseBruce Ashfield
This is the 4.18.44 stable release # gpg: Signature made Tue 17 Sep 2019 10:35:59 AM EDT # gpg: using RSA key EBCE84042C07D1D6 # gpg: Can't check signature: No public key
2019-09-21x86/speculation/swapgs: Exclude ATOMs from speculation through SWAPGSThomas Gleixner
commit f36cf386e3fec258a341d446915862eded3e13d8 upstream. Intel provided the following information: On all current Atom processors, instructions that use a segment register value (e.g. a load or store) will not speculatively execute before the last writer of that segment retires. Thus they will not use a speculatively written segment value. That means on ATOMs there is no speculation through SWAPGS, so the SWAPGS entry paths can be excluded from the extra LFENCE if PTI is disabled. Create a separate bug flag for the through SWAPGS speculation and mark all out-of-order ATOMs and AMD/HYGON CPUs as not affected. The in-order ATOMs are excluded from the whole mitigation mess anyway. Reported-by: Andrew Cooper <andrew.cooper3@citrix.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Tyler Hicks <tyhicks@canonical.com> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> [PG: drop HYGON chunk - doesn't exist in 4.18.x kernels.] Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-09-21x86/speculation: Enable Spectre v1 swapgs mitigationsJosh Poimboeuf
commit a2059825986a1c8143fd6698774fa9d83733bb11 upstream. The previous commit added macro calls in the entry code which mitigate the Spectre v1 swapgs issue if the X86_FEATURE_FENCE_SWAPGS_* features are enabled. Enable those features where applicable. The mitigations may be disabled with "nospectre_v1" or "mitigations=off". There are different features which can affect the risk of attack: - When FSGSBASE is enabled, unprivileged users are able to place any value in GS, using the wrgsbase instruction. This means they can write a GS value which points to any value in kernel space, which can be useful with the following gadget in an interrupt/exception/NMI handler: if (coming from user space) swapgs mov %gs:<percpu_offset>, %reg1 // dependent load or store based on the value of %reg // for example: mov %(reg1), %reg2 If an interrupt is coming from user space, and the entry code speculatively skips the swapgs (due to user branch mistraining), it may speculatively execute the GS-based load and a subsequent dependent load or store, exposing the kernel data to an L1 side channel leak. Note that, on Intel, a similar attack exists in the above gadget when coming from kernel space, if the swapgs gets speculatively executed to switch back to the user GS. On AMD, this variant isn't possible because swapgs is serializing with respect to future GS-based accesses. NOTE: The FSGSBASE patch set hasn't been merged yet, so the above case doesn't exist quite yet. - When FSGSBASE is disabled, the issue is mitigated somewhat because unprivileged users must use prctl(ARCH_SET_GS) to set GS, which restricts GS values to user space addresses only. That means the gadget would need an additional step, since the target kernel address needs to be read from user space first. Something like: if (coming from user space) swapgs mov %gs:<percpu_offset>, %reg1 mov (%reg1), %reg2 // dependent load or store based on the value of %reg2 // for example: mov %(reg2), %reg3 It's difficult to audit for this gadget in all the handlers, so while there are no known instances of it, it's entirely possible that it exists somewhere (or could be introduced in the future). Without tooling to analyze all such code paths, consider it vulnerable. Effects of SMAP on the !FSGSBASE case: - If SMAP is enabled, and the CPU reports RDCL_NO (i.e., not susceptible to Meltdown), the kernel is prevented from speculatively reading user space memory, even L1 cached values. This effectively disables the !FSGSBASE attack vector. - If SMAP is enabled, but the CPU *is* susceptible to Meltdown, SMAP still prevents the kernel from speculatively reading user space memory. But it does *not* prevent the kernel from reading the user value from L1, if it has already been cached. This is probably only a small hurdle for an attacker to overcome. Thanks to Dave Hansen for contributing the speculative_smap() function. Thanks to Andrew Cooper for providing the inside scoop on whether swapgs is serializing on AMD. [ tglx: Fixed the USER fence decision and polished the comment as suggested by Dave Hansen ] Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-09-21x86/cpufeatures: Combine word 11 and 12 into a new scattered features wordFenghua Yu
commit acec0ce081de0c36459eea91647faf99296445a3 upstream. It's a waste for the four X86_FEATURE_CQM_* feature bits to occupy two whole feature bits words. To better utilize feature words, re-define word 11 to host scattered features and move the four X86_FEATURE_CQM_* features into Linux defined word 11. More scattered features can be added in word 11 in the future. Rename leaf 11 in cpuid_leafs to CPUID_LNX_4 to reflect it's a Linux-defined leaf. Rename leaf 12 as CPUID_DUMMY which will be replaced by a meaningful name in the next patch when CPUID.7.1:EAX occupies world 12. Maximum number of RMID and cache occupancy scale are retrieved from CPUID.0xf.1 after scattered CQM features are enumerated. Carve out the code into a separate function. KVM doesn't support resctrl now. So it's safe to move the X86_FEATURE_CQM_* features to scattered features word 11 for KVM. Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Aaron Lewis <aaronlewis@google.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Babu Moger <babu.moger@amd.com> Cc: "Chang S. Bae" <chang.seok.bae@intel.com> Cc: "Sean J Christopherson" <sean.j.christopherson@intel.com> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Juergen Gross <jgross@suse.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: kvm ML <kvm@vger.kernel.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Nadav Amit <namit@vmware.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Pavel Tatashin <pasha.tatashin@oracle.com> Cc: Peter Feiner <pfeiner@google.com> Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Cc: Ravi V Shankar <ravi.v.shankar@intel.com> Cc: Sherry Hurwitz <sherry.hurwitz@amd.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thomas Lendacky <Thomas.Lendacky@amd.com> Cc: x86 <x86@kernel.org> Link: https://lkml.kernel.org/r/1560794416-217638-2-git-send-email-fenghua.yu@intel.com Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-09-21x86/cpufeatures: Carve out CQM features retrievalBorislav Petkov
commit 45fc56e629caa451467e7664fbd4c797c434a6c4 upstream. ... into a separate function for better readability. Split out from a patch from Fenghua Yu <fenghua.yu@intel.com> to keep the mechanical, sole code movement separate for easy review. No functional changes. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: x86@kernel.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-09-16x86/microcode: Fix the microcode load on CPU hotplug for realThomas Gleixner
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
2019-09-16x86/ftrace: Fix warning and considate ftrace_jmp_replace() and ↵Steven Rostedt (VMware)
ftrace_call_replace() commit 745cfeaac09ce359130a5451d90cb0bd4094c290 upstream. Arnd reported the following compiler warning: arch/x86/kernel/ftrace.c:669:23: error: 'ftrace_jmp_replace' defined but not used [-Werror=unused-function] The ftrace_jmp_replace() function now only has a single user and should be simply moved by that user. But looking at the code, it shows that ftrace_jmp_replace() is similar to ftrace_call_replace() except that instead of using the opcode of 0xe8 it uses 0xe9. It makes more sense to consolidate that function into one implementation that both ftrace_jmp_replace() and ftrace_call_replace() use by passing in the op code separate. The structure in ftrace_code_union is also modified to replace the "e8" field with the more appropriate name "op". Cc: stable@vger.kernel.org Reported-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Arnd Bergmann <arnd@arndb.de> Link: http://lkml.kernel.org/r/20190304200748.1418790-1-arnd@arndb.de Fixes: d2a68c4effd8 ("x86/ftrace: Do not call function graph from dynamic trampolines") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-09-16x86/CPU/AMD: Don't force the CPB cap when running under a hypervisorFrank van der Linden
commit 2ac44ab608705948564791ce1d15d43ba81a1e38 upstream. 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: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-09-16x86/resctrl: Prevent NULL pointer dereference when local MBM is disabledPrarit Bhargava
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: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-09-16x86/microcode, cpuhotplug: Add a microcode loader CPU hotplug callbackBorislav Petkov
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: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-09-15Merge tag 'v4.18.43' into v4.18/standard/baseBruce Ashfield
This is the 4.18.43 stable release
2019-09-12x86/kprobes: Set instruction page as executableNadav Amit
commit 7298e24f904224fa79eb8fd7e0fbd78950ccf2db upstream. 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: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-09-12x86/ftrace: Set trampoline pages as executableNadav Amit
commit 3c0dab44e22782359a0a706cbce72de99a22aa75 upstream. 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: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-09-12x86/ftrace: Do not call function graph from dynamic trampolinesSteven Rostedt (VMware)
commit d2a68c4effd821f0871d20368f76b609349c8a3b upstream. Since commit 79922b8009c07 ("ftrace: Optimize function graph to be called directly"), dynamic trampolines should not be calling the function graph tracer at the end. If they do, it could cause the function graph tracer to trace functions that it filtered out. Right now it does not cause a problem because there's a test to check if the function graph tracer is attached to the same function as the function tracer, which for now is true. But the function graph tracer is undergoing changes that can make this no longer true which will cause the function graph tracer to trace other functions. For example: # cd /sys/kernel/tracing/ # echo do_IRQ > set_ftrace_filter # mkdir instances/foo # echo ip_rcv > instances/foo/set_ftrace_filter # echo function_graph > current_tracer # echo function > instances/foo/current_tracer Would cause the function graph tracer to trace both do_IRQ and ip_rcv, if the current tests change. As the current tests prevent this from being a problem, this code does not need to be backported. But it does make the code cleaner. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: x86@kernel.org Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-09-12Revert "x86/build: Move _etext to actual end of .text"Greg Kroah-Hartman
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> [PG: add the revert found in 4.19.x-stable trees.] Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-08-25Merge tag 'v4.18.42' into v4.18/standard/baseBruce Ashfield
This is the 4.18.42 stable release
2019-08-17x86/mce: Handle varying MCA bank countsYazen Ghannam
commit 006c077041dc73b9490fffc4c6af5befe0687110 upstream. 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 [PG: update file paths for older code base.] Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-08-17x86/mce: Fix machine_check_poll() tests for error typesTony Luck
commit f19501aa07f18268ab14f458b51c1c6b7f72a134 upstream. 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 [PG: update for older file paths in 4.18.x code base.] Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-08-17x86/uaccess, signal: Fix AC=1 bloatPeter Zijlstra
commit 88e4718275c1bddca6f61f300688b4553dc8584b upstream. 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: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-08-17x86/microcode: Fix the ancient deprecated microcode loading methodBorislav Petkov
commit 24613a04ad1c0588c10f4b5403ca60a73d164051 upstream. 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: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-08-17x86/irq/64: Limit IST stack overflow check to #DB stackThomas Gleixner
commit 7dbcf2b0b770eeb803a416ee8dcbef78e6389d40 upstream. 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: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-08-07Merge tag 'v4.18.41' into v4.18/standard/baseBruce Ashfield
This is the 4.18.41 stable release
2019-08-02x86/build: Move _etext to actual end of .textKees Cook
commit 392bef709659abea614abfe53cf228e7a59876a4 upstream. 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: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-08-02x86/modules: Avoid breaking W^X while loading modulesNadav Amit
commit f2c65fb3221adc6b73b0549fc7ba892022db9797 upstream. 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: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-08-02x86/alternatives, jumplabel: Use text_poke_early() before mm_init()Pavel Tatashin
commit 6fffacb30349e0903602d664f7ab6fc87e85162e upstream. It supposed to be safe to modify static branches after jump_label_init(). But, because static key modifying code eventually calls text_poke() it can end up accessing a struct page which has not been initialized yet. Here is how to quickly reproduce the problem. Insert code like this into init/main.c: | +static DEFINE_STATIC_KEY_FALSE(__test); | asmlinkage __visible void __init start_kernel(void) | { | char *command_line; |@@ -587,6 +609,10 @@ asmlinkage __visible void __init start_kernel(void) | vfs_caches_init_early(); | sort_main_extable(); | trap_init(); |+ { |+ static_branch_enable(&__test); |+ WARN_ON(!static_branch_likely(&__test)); |+ } | mm_init(); The following warnings show-up: WARNING: CPU: 0 PID: 0 at arch/x86/kernel/alternative.c:701 text_poke+0x20d/0x230 RIP: 0010:text_poke+0x20d/0x230 Call Trace: ? text_poke_bp+0x50/0xda ? arch_jump_label_transform+0x89/0xe0 ? __jump_label_update+0x78/0xb0 ? static_key_enable_cpuslocked+0x4d/0x80 ? static_key_enable+0x11/0x20 ? start_kernel+0x23e/0x4c8 ? secondary_startup_64+0xa5/0xb0 ---[ end trace abdc99c031b8a90a ]--- If the code above is moved after mm_init(), no warning is shown, as struct pages are initialized during handover from memblock. Use text_poke_early() in static branching until early boot IRQs are enabled and from there switch to text_poke. Also, ensure text_poke() is never invoked when unitialized memory access may happen by using adding a !after_bootmem assertion. Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Cc: steven.sistare@oracle.com Cc: daniel.m.jordan@oracle.com Cc: linux@armlinux.org.uk Cc: schwidefsky@de.ibm.com Cc: heiko.carstens@de.ibm.com Cc: john.stultz@linaro.org Cc: sboyd@codeaurora.org Cc: hpa@zytor.com Cc: douly.fnst@cn.fujitsu.com Cc: peterz@infradead.org Cc: prarit@redhat.com Cc: feng.tang@intel.com Cc: pmladek@suse.com Cc: gnomes@lxorguk.ukuu.org.uk Cc: linux-s390@vger.kernel.org Cc: boris.ostrovsky@oracle.com Cc: jgross@suse.com Cc: pbonzini@redhat.com Link: https://lkml.kernel.org/r/20180719205545.16512-9-pasha.tatashin@oracle.com Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-08-02ftrace/x86_64: Emulate call function while updating in breakpoint handlerPeter Zijlstra
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: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-06-03Merge tag 'v4.18.40' into v4.18/standard/baseBruce Ashfield
This is the 4.18.40 stable release
2019-05-30sched/x86: Save [ER]FLAGS on context switchPeter Zijlstra
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: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-30x86/speculation/mds: Revert CPU buffer clear on double fault exitAndy Lutomirski
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: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-30x86/kprobes: Avoid kretprobe recursion bugMasami Hiramatsu
commit b191fa96ea6dc00d331dcc28c1f7db5e075693a0 upstream. 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> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-30x86/reboot, efi: Use EFI reboot for Acer TravelMate X514-51TJian-Hong Pan
commit 0082517fa4bce073e7cf542633439f26538a14cc upstream. 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> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-30x86/build/lto: Fix truncated .bss with -fdata-sectionsSami Tolvanen
commit 6a03469a1edc94da52b65478f1e00837add869a3 upstream. 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> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-29Merge tag 'v4.18.39' into v4.18/standard/baseBruce Ashfield
This is the 4.18.39 stable release
2019-05-23x86/mce: Improve error message when kernel cannot recover, p2Tony Luck
commit 41f035a86b5b72a4f947c38e94239d20d595352a upstream. In c7d606f560e4 ("x86/mce: Improve error message when kernel cannot recover") a case was added for a machine check caused by a DATA access to poison memory from the kernel. A case should have been added also for an uncorrectable error during an instruction fetch in the kernel. Add that extra case so the error message now reads: mce: [Hardware Error]: Machine check: Instruction fetch error in kernel Fixes: c7d606f560e4 ("x86/mce: Improve error message when kernel cannot recover") Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Pu Wen <puwen@hygon.cn> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190225205940.15226-1-tony.luck@intel.com Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-21Merge tag 'v4.18.38' into v4.18/standard/baseBruce Ashfield
This is the 4.18.38 stable release
2019-05-16Merge tag 'v4.18.37' into v4.18/standard/baseBruce Ashfield
This is the 4.18.37 stable release
2019-05-15x86/fpu: Don't export __kernel_fpu_{begin,end}()Sebastian Andrzej Siewior
commit 12209993e98c5fa1855c467f22a24e3d5b8be205 upstream. There is one user of __kernel_fpu_begin() and before invoking it, it invokes preempt_disable(). So it could invoke kernel_fpu_begin() right away. The 32bit version of arch_efi_call_virt_setup() and arch_efi_call_virt_teardown() does this already. The comment above *kernel_fpu*() claims that before invoking __kernel_fpu_begin() preemption should be disabled and that KVM is a good example of doing it. Well, KVM doesn't do that since commit f775b13eedee2 ("x86,kvm: move qemu/guest FPU switching out to vcpu_run") so it is not an example anymore. With EFI gone as the last user of __kernel_fpu_{begin|end}(), both can be made static and not exported anymore. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Rik van Riel <riel@surriel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Nicolai Stange <nstange@suse.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm ML <kvm@vger.kernel.org> Cc: linux-efi <linux-efi@vger.kernel.org> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20181129150210.2k4mawt37ow6c2vq@linutronix.de Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-15x86/speculation: Prevent deadlock on ssb_state::lockThomas Gleixner
commit 2f5fb19341883bb6e37da351bc3700489d8506a7 upstream. Mikhail reported a lockdep splat related to the AMD specific ssb_state lock: CPU0 CPU1 lock(&st->lock); local_irq_disable(); lock(&(&sighand->siglock)->rlock); lock(&st->lock); <Interrupt> lock(&(&sighand->siglock)->rlock); *** DEADLOCK *** The connection between sighand->siglock and st->lock comes through seccomp, which takes st->lock while holding sighand->siglock. Make sure interrupts are disabled when __speculation_ctrl_update() is invoked via prctl() -> speculation_ctrl_update(). Add a lockdep assert to catch future offenders. Fixes: 1f50ddb4f418 ("x86/speculation: Handle HT correctly on AMD") Reported-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com> Cc: Thomas Lendacky <thomas.lendacky@amd.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1904141948200.4917@nanos.tec.linutronix.de Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-15x86/cpu/bugs: Use __initconst for 'const' init dataAndi Kleen
commit 1de7edbb59c8f1b46071f66c5c97b8a59569eb51 upstream. 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 Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-15x86/kprobes: Verify stack frame on kretprobeMasami Hiramatsu
commit 3ff9c075cc767b3060bdac12da72fc94dd7da1b8 upstream. 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> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-14x86/speculation/mds: Add 'mitigations=' support for MDSJosh Poimboeuf
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> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-14x86/speculation: Support 'mitigations=' cmdline optionJosh Poimboeuf
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> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-14x86/speculation/mds: Print SMT vulnerable on MSBDS with mitigations offKonrad Rzeszutek Wilk
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> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-14x86/speculation/mds: Fix commentBoris Ostrovsky
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> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-14x86/speculation/mds: Add SMT warning messageJosh Poimboeuf
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> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-14x86/speculation: Move arch_smt_update() call to after mitigation decisionsJosh Poimboeuf
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> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-14x86/speculation/mds: Add mds=full,nosmt cmdline optionJosh Poimboeuf
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> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-14Documentation: Move L1TF to separate directoryThomas Gleixner
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> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2019-05-14x86/speculation/mds: Add mitigation mode VMWERVThomas Gleixner
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> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>