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* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2018-05-261-13/+30
|\ | | | | | | | | | | | | Lots of easy overlapping changes in the confict resolutions here. Signed-off-by: David S. Miller <davem@davemloft.net>
| * x86/bugs: Remove x86_spec_ctrl_set()Thomas Gleixner2018-05-171-2/+0
| | | | | | | | | | | | | | | | | | | | | | x86_spec_ctrl_set() is only used in bugs.c and the extra mask checks there provide no real value as both call sites can just write x86_spec_ctrl_base to MSR_SPEC_CTRL. x86_spec_ctrl_base is valid and does not need any extra masking or checking. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| * x86/bugs: Expose x86_spec_ctrl_base directlyThomas Gleixner2018-05-171-11/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | x86_spec_ctrl_base is the system wide default value for the SPEC_CTRL MSR. x86_spec_ctrl_get_default() returns x86_spec_ctrl_base and was intended to prevent modification to that variable. Though the variable is read only after init and globaly visible already. Remove the function and export the variable instead. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| * x86/cpu: Make alternative_msr_write work for 32-bit codeJim Mattson2018-05-141-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | Cast val and (val >> 32) to (u32), so that they fit in a general-purpose register in both 32-bit and 64-bit code. [ tglx: Made it u32 instead of uintptr_t ] Fixes: c65732e4f721 ("x86/cpu: Restore CPUID_8000_0008_EBX reload") Signed-off-by: Jim Mattson <jmattson@google.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
| * x86/speculation: Make "seccomp" the default mode for Speculative Store BypassKees Cook2018-05-051-0/+1
| | | | | | | | | | | | | | | | | | | | Unless explicitly opted out of, anything running under seccomp will have SSB mitigations enabled. Choosing the "prctl" mode will disable this. [ tglx: Adjusted it to the new arch_seccomp_spec_mitigate() mechanism ] Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * x86/speculation: Add prctl for Speculative Store Bypass mitigationThomas Gleixner2018-05-031-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add prctl based control for Speculative Store Bypass mitigation and make it the default mitigation for Intel and AMD. Andi Kleen provided the following rationale (slightly redacted): There are multiple levels of impact of Speculative Store Bypass: 1) JITed sandbox. It cannot invoke system calls, but can do PRIME+PROBE and may have call interfaces to other code 2) Native code process. No protection inside the process at this level. 3) Kernel. 4) Between processes. The prctl tries to protect against case (1) doing attacks. If the untrusted code can do random system calls then control is already lost in a much worse way. So there needs to be system call protection in some way (using a JIT not allowing them or seccomp). Or rather if the process can subvert its environment somehow to do the prctl it can already execute arbitrary code, which is much worse than SSB. To put it differently, the point of the prctl is to not allow JITed code to read data it shouldn't read from its JITed sandbox. If it already has escaped its sandbox then it can already read everything it wants in its address space, and do much worse. The ability to control Speculative Store Bypass allows to enable the protection selectively without affecting overall system performance. Based on an initial patch from Tim Chen. Completely rewritten. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| * x86/speculation: Create spec-ctrl.h to avoid include hellThomas Gleixner2018-05-031-14/+0
| | | | | | | | | | | | | | | | | | | | | | Having everything in nospec-branch.h creates a hell of dependencies when adding the prctl based switching mechanism. Move everything which is not required in nospec-branch.h to spec-ctrl.h and fix up the includes in the relevant files. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Ingo Molnar <mingo@kernel.org>
| * x86/bugs/AMD: Add support to disable RDS on Fam[15,16,17]h if requestedKonrad Rzeszutek Wilk2018-05-031-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | AMD does not need the Speculative Store Bypass mitigation to be enabled. The parameters for this are already available and can be done via MSR C001_1020. Each family uses a different bit in that MSR for this. [ tglx: Expose the bit mask via a variable and move the actual MSR fiddling into the bugs code as that's the right thing to do and also required to prepare for dynamic enable/disable ] Suggested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org>
| * x86/bugs: Provide boot parameters for the spec_store_bypass_disable mitigationKonrad Rzeszutek Wilk2018-05-031-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Contemporary high performance processors use a common industry-wide optimization known as "Speculative Store Bypass" in which loads from addresses to which a recent store has occurred may (speculatively) see an older value. Intel refers to this feature as "Memory Disambiguation" which is part of their "Smart Memory Access" capability. Memory Disambiguation can expose a cache side-channel attack against such speculatively read values. An attacker can create exploit code that allows them to read memory outside of a sandbox environment (for example, malicious JavaScript in a web page), or to perform more complex attacks against code running within the same privilege level, e.g. via the stack. As a first step to mitigate against such attacks, provide two boot command line control knobs: nospec_store_bypass_disable spec_store_bypass_disable=[off,auto,on] By default affected x86 processors will power on with Speculative Store Bypass enabled. Hence the provided kernel parameters are written from the point of view of whether to enable a mitigation or not. The parameters are as follows: - auto - Kernel detects whether your CPU model contains an implementation of Speculative Store Bypass and picks the most appropriate mitigation. - on - disable Speculative Store Bypass - off - enable Speculative Store Bypass [ tglx: Reordered the checks so that the whole evaluation is not done when the CPU does not support RDS ] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Ingo Molnar <mingo@kernel.org>
| * x86/bugs, KVM: Support the combination of guest and host IBRSKonrad Rzeszutek Wilk2018-05-031-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A guest may modify the SPEC_CTRL MSR from the value used by the kernel. Since the kernel doesn't use IBRS, this means a value of zero is what is needed in the host. But the 336996-Speculative-Execution-Side-Channel-Mitigations.pdf refers to the other bits as reserved so the kernel should respect the boot time SPEC_CTRL value and use that. This allows to deal with future extensions to the SPEC_CTRL interface if any at all. Note: This uses wrmsrl() instead of native_wrmsl(). I does not make any difference as paravirt will over-write the callq *0xfff.. with the wrmsrl assembler code. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Ingo Molnar <mingo@kernel.org>
| * x86/bugs: Read SPEC_CTRL MSR during boot and re-use reserved bitsKonrad Rzeszutek Wilk2018-05-031-4/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The 336996-Speculative-Execution-Side-Channel-Mitigations.pdf refers to all the other bits as reserved. The Intel SDM glossary defines reserved as implementation specific - aka unknown. As such at bootup this must be taken it into account and proper masking for the bits in use applied. A copy of this document is available at https://bugzilla.kernel.org/show_bug.cgi?id=199511 [ tglx: Made x86_spec_ctrl_base __ro_after_init ] Suggested-by: Jon Masters <jcm@redhat.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Ingo Molnar <mingo@kernel.org>
| * x86/nospec: Simplify alternative_msr_write()Linus Torvalds2018-05-031-9/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The macro is not type safe and I did look for why that "g" constraint for the asm doesn't work: it's because the asm is more fundamentally wrong. It does movl %[val], %%eax but "val" isn't a 32-bit value, so then gcc will pass it in a register, and generate code like movl %rsi, %eax and gas will complain about a nonsensical 'mov' instruction (it's moving a 64-bit register to a 32-bit one). Passing it through memory will just hide the real bug - gcc still thinks the memory location is 64-bit, but the "movl" will only load the first 32 bits and it all happens to work because x86 is little-endian. Convert it to a type safe inline function with a little trick which hands the feature into the ALTERNATIVE macro. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org>
* | bpf, x64: clean up retpoline emission slightlyDaniel Borkmann2018-05-141-15/+14
| | | | | | | | | | | | | | | | | | Make the RETPOLINE_{RA,ED}X_BPF_JIT() a bit more readable by cleaning up the macro, aligning comments and spacing. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | bpf, x86_32: add eBPF JIT compiler for ia32Wang YanQing2018-05-031-3/+27
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The JIT compiler emits ia32 bit instructions. Currently, It supports eBPF only. Classic BPF is supported because of the conversion by BPF core. Almost all instructions from eBPF ISA supported except the following: BPF_ALU64 | BPF_DIV | BPF_K BPF_ALU64 | BPF_DIV | BPF_X BPF_ALU64 | BPF_MOD | BPF_K BPF_ALU64 | BPF_MOD | BPF_X BPF_STX | BPF_XADD | BPF_W BPF_STX | BPF_XADD | BPF_DW It doesn't support BPF_JMP|BPF_CALL with BPF_PSEUDO_CALL at the moment. IA32 has few general purpose registers, EAX|EDX|ECX|EBX|ESI|EDI. I use EAX|EDX|ECX|EBX as temporary registers to simulate instructions in eBPF ISA, and allocate ESI|EDI to BPF_REG_AX for constant blinding, all others eBPF registers, R0-R10, are simulated through scratch space on stack. The reasons behind the hardware registers allocation policy are: 1:MUL need EAX:EDX, shift operation need ECX, so they aren't fit for general eBPF 64bit register simulation. 2:We need at least 4 registers to simulate most eBPF ISA operations on registers operands instead of on register&memory operands. 3:We need to put BPF_REG_AX on hardware registers, or constant blinding will degrade jit performance heavily. Tested on PC (Intel(R) Core(TM) i5-5200U CPU). Testing results on i5-5200U: 1) test_bpf: Summary: 349 PASSED, 0 FAILED, [319/341 JIT'ed] 2) test_progs: Summary: 83 PASSED, 0 FAILED. 3) test_lpm: OK 4) test_lru_map: OK 5) test_verifier: Summary: 828 PASSED, 0 FAILED. Above tests are all done in following two conditions separately: 1:bpf_jit_enable=1 and bpf_jit_harden=0 2:bpf_jit_enable=1 and bpf_jit_harden=2 Below are some numbers for this jit implementation: Note: I run test_progs in kselftest 100 times continuously for every condition, the numbers are in format: total/times=avg. The numbers that test_bpf reports show almost the same relation. a:jit_enable=0 and jit_harden=0 b:jit_enable=1 and jit_harden=0 test_pkt_access:PASS:ipv4:15622/100=156 test_pkt_access:PASS:ipv4:10674/100=106 test_pkt_access:PASS:ipv6:9130/100=91 test_pkt_access:PASS:ipv6:4855/100=48 test_xdp:PASS:ipv4:240198/100=2401 test_xdp:PASS:ipv4:138912/100=1389 test_xdp:PASS:ipv6:137326/100=1373 test_xdp:PASS:ipv6:68542/100=685 test_l4lb:PASS:ipv4:61100/100=611 test_l4lb:PASS:ipv4:37302/100=373 test_l4lb:PASS:ipv6:101000/100=1010 test_l4lb:PASS:ipv6:55030/100=550 c:jit_enable=1 and jit_harden=2 test_pkt_access:PASS:ipv4:10558/100=105 test_pkt_access:PASS:ipv6:5092/100=50 test_xdp:PASS:ipv4:131902/100=1319 test_xdp:PASS:ipv6:77932/100=779 test_l4lb:PASS:ipv4:38924/100=389 test_l4lb:PASS:ipv6:57520/100=575 The numbers show we get 30%~50% improvement. See Documentation/networking/filter.txt for more information. Changelog: Changes v5-v6: 1:Add do {} while (0) to RETPOLINE_RAX_BPF_JIT for consistence reason. 2:Clean up non-standard comments, reported by Daniel Borkmann. 3:Fix a memory leak issue, repoted by Daniel Borkmann. Changes v4-v5: 1:Delete is_on_stack, BPF_REG_AX is the only one on real hardware registers, so just check with it. 2:Apply commit 1612a981b766 ("bpf, x64: fix JIT emission for dead code"), suggested by Daniel Borkmann. Changes v3-v4: 1:Fix changelog in commit. I install llvm-6.0, then test_progs willn't report errors. I submit another patch: "bpf: fix misaligned access for BPF_PROG_TYPE_PERF_EVENT program type on x86_32 platform" to fix another problem, after that patch, test_verifier willn't report errors too. 2:Fix clear r0[1] twice unnecessarily in *BPF_IND|BPF_ABS* simulation. Changes v2-v3: 1:Move BPF_REG_AX to real hardware registers for performance reason. 3:Using bpf_load_pointer instead of bpf_jit32.S, suggested by Daniel Borkmann. 4:Delete partial codes in 1c2a088a6626, suggested by Daniel Borkmann. 5:Some bug fixes and comments improvement. Changes v1-v2: 1:Fix bug in emit_ia32_neg64. 2:Fix bug in emit_ia32_arsh_r64. 3:Delete filename in top level comment, suggested by Thomas Gleixner. 4:Delete unnecessary boiler plate text, suggested by Thomas Gleixner. 5:Rewrite some words in changelog. 6:CodingSytle improvement and a little more comments. Signed-off-by: Wang YanQing <udknight@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* Merge branch 'x86-pti-for-linus' of ↵Linus Torvalds2018-03-181-1/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86/pti updates from Thomas Gleixner: "Another set of melted spectrum updates: - Iron out the last late microcode loading issues by actually checking whether new microcode is present and preventing the CPU synchronization to run into a timeout induced hang. - Remove Skylake C2 from the microcode blacklist according to the latest Intel documentation - Fix the VM86 POPF emulation which traps if VIP is set, but VIF is not. Enhance the selftests to catch that kind of issue - Annotate indirect calls/jumps for objtool on 32bit. This is not a functional issue, but for consistency sake its the right thing to do. - Fix a jump label build warning observed on SPARC64 which uses 32bit storage for the code location which is casted to 64 bit pointer w/o extending it to 64bit first. - Add two new cpufeature bits. Not really an urgent issue, but provides them for both x86 and x86/kvm work. No impact on the current kernel" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/microcode: Fix CPU synchronization routine x86/microcode: Attempt late loading only when new microcode is present x86/speculation: Remove Skylake C2 from Speculation Control microcode blacklist jump_label: Fix sparc64 warning x86/speculation, objtool: Annotate indirect calls/jumps for objtool on 32-bit kernels x86/vm86/32: Fix POPF emulation selftests/x86/entry_from_vm86: Add test cases for POPF selftests/x86/entry_from_vm86: Exit with 1 if we fail x86/cpufeatures: Add Intel PCONFIG cpufeature x86/cpufeatures: Add Intel Total Memory Encryption cpufeature
| * x86/speculation, objtool: Annotate indirect calls/jumps for objtool on ↵Andy Whitcroft2018-03-141-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 32-bit kernels In the following commit: 9e0e3c5130e9 ("x86/speculation, objtool: Annotate indirect calls/jumps for objtool") ... we added annotations for CALL_NOSPEC/JMP_NOSPEC on 64-bit x86 kernels, but we did not annotate the 32-bit path. Annotate it similarly. Signed-off-by: Andy Whitcroft <apw@canonical.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 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> Link: http://lkml.kernel.org/r/20180314112427.22351-1-apw@canonical.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | Merge branch 'x86-pti-for-linus' of ↵Linus Torvalds2018-02-261-20/+118
|\ \ | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "Yet another pile of melted spectrum related changes: - sanitize the array_index_nospec protection mechanism: Remove the overengineered array_index_nospec_mask_check() magic and allow const-qualified types as index to avoid temporary storage in a non-const local variable. - make the microcode loader more robust by properly propagating error codes. Provide information about new feature bits after micro code was updated so administrators can act upon. - optimizations of the entry ASM code which reduce code footprint and make the code simpler and faster. - fix the {pmd,pud}_{set,clear}_flags() implementations to work properly on paravirt kernels by removing the address translation operations. - revert the harmful vmexit_fill_RSB() optimization - use IBRS around firmware calls - teach objtool about retpolines and add annotations for indirect jumps and calls. - explicitly disable jumplabel patching in __init code and handle patching failures properly instead of silently ignoring them. - remove indirect paravirt calls for writing the speculation control MSR as these calls are obviously proving the same attack vector which is tried to be mitigated. - a few small fixes which address build issues with recent compiler and assembler versions" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (38 commits) KVM/VMX: Optimize vmx_vcpu_run() and svm_vcpu_run() by marking the RDMSR path as unlikely() KVM/x86: Remove indirect MSR op calls from SPEC_CTRL objtool, retpolines: Integrate objtool with retpoline support more closely x86/entry/64: Simplify ENCODE_FRAME_POINTER extable: Make init_kernel_text() global jump_label: Warn on failed jump_label patching attempt jump_label: Explicitly disable jump labels in __init code x86/entry/64: Open-code switch_to_thread_stack() x86/entry/64: Move ASM_CLAC to interrupt_entry() x86/entry/64: Remove 'interrupt' macro x86/entry/64: Move the switch_to_thread_stack() call to interrupt_entry() x86/entry/64: Move ENTER_IRQ_STACK from interrupt macro to interrupt_entry x86/entry/64: Move PUSH_AND_CLEAR_REGS from interrupt macro to helper function x86/speculation: Move firmware_restrict_branch_speculation_*() from C to CPP objtool: Add module specific retpoline rules objtool: Add retpoline validation objtool: Use existing global variables for options x86/mm/sme, objtool: Annotate indirect call in sme_encrypt_execute() x86/boot, objtool: Annotate indirect jump in secondary_startup_64() x86/paravirt, objtool: Annotate indirect calls ...
| * x86/speculation: Move firmware_restrict_branch_speculation_*() from C to CPPIngo Molnar2018-02-211-12/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | firmware_restrict_branch_speculation_*() recently started using preempt_enable()/disable(), but those are relatively high level primitives and cause build failures on some 32-bit builds. Since we want to keep <asm/nospec-branch.h> low level, convert them to macros to avoid header hell... Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: arjan.van.de.ven@intel.com Cc: bp@alien8.de Cc: dave.hansen@intel.com Cc: jmattson@google.com Cc: karahmed@amazon.de Cc: kvm@vger.kernel.org Cc: pbonzini@redhat.com Cc: rkrcmar@redhat.com Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * x86/speculation, objtool: Annotate indirect calls/jumps for objtoolPeter Zijlstra2018-02-211-4/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Annotate the indirect calls/jumps in the CALL_NOSPEC/JUMP_NOSPEC alternatives. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: David Woodhouse <dwmw@amazon.co.uk> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * x86/speculation: Use IBRS if available before calling into firmwareDavid Woodhouse2018-02-201-9/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Retpoline means the kernel is safe because it has no indirect branches. But firmware isn't, so use IBRS for firmware calls if it's available. Block preemption while IBRS is set, although in practice the call sites already had to be doing that. Ignore hpwdt.c for now. It's taking spinlocks and calling into firmware code, from an NMI handler. I don't want to touch that with a bargepole. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: arjan.van.de.ven@intel.com Cc: bp@alien8.de Cc: dave.hansen@intel.com Cc: jmattson@google.com Cc: karahmed@amazon.de Cc: kvm@vger.kernel.org Cc: pbonzini@redhat.com Cc: rkrcmar@redhat.com Link: http://lkml.kernel.org/r/1519037457-7643-2-git-send-email-dwmw@amazon.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * Revert "x86/retpoline: Simplify vmexit_fill_RSB()"David Woodhouse2018-02-201-7/+63
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 1dde7415e99933bb7293d6b2843752cbdb43ec11. By putting the RSB filling out of line and calling it, we waste one RSB slot for returning from the function itself, which means one fewer actual function call we can make if we're doing the Skylake abomination of call-depth counting. It also changed the number of RSB stuffings we do on vmexit from 32, which was correct, to 16. Let's just stop with the bikeshedding; it didn't actually *fix* anything anyway. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: arjan.van.de.ven@intel.com Cc: bp@alien8.de Cc: dave.hansen@intel.com Cc: jmattson@google.com Cc: karahmed@amazon.de Cc: kvm@vger.kernel.org Cc: pbonzini@redhat.com Cc: rkrcmar@redhat.com Link: http://lkml.kernel.org/r/1519037457-7643-4-git-send-email-dwmw@amazon.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | bpf, x64: implement retpoline for tail callDaniel Borkmann2018-02-221-0/+37
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement a retpoline [0] for the BPF tail call JIT'ing that converts the indirect jump via jmp %rax that is used to make the long jump into another JITed BPF image. Since this is subject to speculative execution, we need to control the transient instruction sequence here as well when CONFIG_RETPOLINE is set, and direct it into a pause + lfence loop. The latter aligns also with what gcc / clang emits (e.g. [1]). JIT dump after patch: # bpftool p d x i 1 0: (18) r2 = map[id:1] 2: (b7) r3 = 0 3: (85) call bpf_tail_call#12 4: (b7) r0 = 2 5: (95) exit With CONFIG_RETPOLINE: # bpftool p d j i 1 [...] 33: cmp %edx,0x24(%rsi) 36: jbe 0x0000000000000072 |* 38: mov 0x24(%rbp),%eax 3e: cmp $0x20,%eax 41: ja 0x0000000000000072 | 43: add $0x1,%eax 46: mov %eax,0x24(%rbp) 4c: mov 0x90(%rsi,%rdx,8),%rax 54: test %rax,%rax 57: je 0x0000000000000072 | 59: mov 0x28(%rax),%rax 5d: add $0x25,%rax 61: callq 0x000000000000006d |+ 66: pause | 68: lfence | 6b: jmp 0x0000000000000066 | 6d: mov %rax,(%rsp) | 71: retq | 72: mov $0x2,%eax [...] * relative fall-through jumps in error case + retpoline for indirect jump Without CONFIG_RETPOLINE: # bpftool p d j i 1 [...] 33: cmp %edx,0x24(%rsi) 36: jbe 0x0000000000000063 |* 38: mov 0x24(%rbp),%eax 3e: cmp $0x20,%eax 41: ja 0x0000000000000063 | 43: add $0x1,%eax 46: mov %eax,0x24(%rbp) 4c: mov 0x90(%rsi,%rdx,8),%rax 54: test %rax,%rax 57: je 0x0000000000000063 | 59: mov 0x28(%rax),%rax 5d: add $0x25,%rax 61: jmpq *%rax |- 63: mov $0x2,%eax [...] * relative fall-through jumps in error case - plain indirect jump as before [0] https://support.google.com/faqs/answer/7625886 [1] https://github.com/gcc-mirror/gcc/commit/a31e654fa107be968b802786d747e962c2fcdb2b Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* x86/speculation: Add <asm/msr-index.h> dependencyPeter Zijlstra2018-02-151-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Joe Konno reported a compile failure resulting from using an MSR without inclusion of <asm/msr-index.h>, and while the current code builds fine (by accident) this needs fixing for future patches. Reported-by: Joe Konno <joe.konno@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: arjan@linux.intel.com Cc: bp@alien8.de Cc: dan.j.williams@intel.com Cc: dave.hansen@linux.intel.com Cc: dwmw2@infradead.org Cc: dwmw@amazon.co.uk Cc: gregkh@linuxfoundation.org Cc: hpa@zytor.com Cc: jpoimboe@redhat.com Cc: linux-tip-commits@vger.kernel.org Cc: luto@kernel.org Fixes: 20ffa1caecca ("x86/speculation: Add basic IBPB (Indirect Branch Prediction Barrier) support") Link: http://lkml.kernel.org/r/20180213132819.GJ25201@hirez.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Revert "x86/speculation: Simplify indirect_branch_prediction_barrier()"David Woodhouse2018-02-131-4/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 64e16720ea0879f8ab4547e3b9758936d483909b. We cannot call C functions like that, without marking all the call-clobbered registers as, well, clobbered. We might have got away with it for now because the __ibp_barrier() function was *fairly* unlikely to actually use any other registers. But no. Just no. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 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: arjan.van.de.ven@intel.com Cc: dave.hansen@intel.com Cc: jmattson@google.com Cc: karahmed@amazon.de Cc: kvm@vger.kernel.org Cc: pbonzini@redhat.com Cc: rkrcmar@redhat.com Cc: sironi@amazon.de Link: http://lkml.kernel.org/r/1518305967-31356-3-git-send-email-dwmw@amazon.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/speculation: Fix typo IBRS_ATT, which should be IBRS_ALLDarren Kenny2018-02-021-1/+1
| | | | | | | | | | | | | | | Fixes: 117cc7a908c83 ("x86/retpoline: Fill return stack buffer on vmexit") Signed-off-by: Darren Kenny <darren.kenny@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Link: https://lkml.kernel.org/r/20180202191220.blvgkgutojecxr3b@starbug-vm.ie.oracle.com
* x86/speculation: Simplify indirect_branch_prediction_barrier()Borislav Petkov2018-01-271-9/+4
| | | | | | | | | | | | | | | | | | | | | | | Make it all a function which does the WRMSR instead of having a hairy inline asm. [dwmw2: export it, fix CONFIG_RETPOLINE issues] Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ak@linux.intel.com Cc: dave.hansen@intel.com Cc: karahmed@amazon.de Cc: arjan@linux.intel.com Cc: torvalds@linux-foundation.org Cc: peterz@infradead.org Cc: bp@alien8.de Cc: pbonzini@redhat.com Cc: tim.c.chen@linux.intel.com Cc: gregkh@linux-foundation.org Link: https://lkml.kernel.org/r/1517070274-12128-4-git-send-email-dwmw@amazon.co.uk
* x86/retpoline: Simplify vmexit_fill_RSB()Borislav Petkov2018-01-271-63/+7
| | | | | | | | | | | | | | | | | | | | | | | | | Simplify it to call an asm-function instead of pasting 41 insn bytes at every call site. Also, add alignment to the macro as suggested here: https://support.google.com/faqs/answer/7625886 [dwmw2: Clean up comments, let it clobber %ebx and just tell the compiler] Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ak@linux.intel.com Cc: dave.hansen@intel.com Cc: karahmed@amazon.de Cc: arjan@linux.intel.com Cc: torvalds@linux-foundation.org Cc: peterz@infradead.org Cc: bp@alien8.de Cc: pbonzini@redhat.com Cc: tim.c.chen@linux.intel.com Cc: gregkh@linux-foundation.org Link: https://lkml.kernel.org/r/1517070274-12128-3-git-send-email-dwmw@amazon.co.uk
* x86/cpufeatures: Clean up Spectre v2 related CPUID flagsDavid Woodhouse2018-01-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We want to expose the hardware features simply in /proc/cpuinfo as "ibrs", "ibpb" and "stibp". Since AMD has separate CPUID bits for those, use them as the user-visible bits. When the Intel SPEC_CTRL bit is set which indicates both IBRS and IBPB capability, set those (AMD) bits accordingly. Likewise if the Intel STIBP bit is set, set the AMD STIBP that's used for the generic hardware capability. Hide the rest from /proc/cpuinfo by putting "" in the comments. Including RETPOLINE and RETPOLINE_AMD which shouldn't be visible there. There are patches to make the sysfs vulnerabilities information non-readable by non-root, and the same should apply to all information about which mitigations are actually in use. Those *shouldn't* appear in /proc/cpuinfo. The feature bit for whether IBPB is actually used, which is needed for ALTERNATIVEs, is renamed to X86_FEATURE_USE_IBPB. Originally-by: Borislav Petkov <bp@suse.de> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ak@linux.intel.com Cc: dave.hansen@intel.com Cc: karahmed@amazon.de Cc: arjan@linux.intel.com Cc: torvalds@linux-foundation.org Cc: peterz@infradead.org Cc: bp@alien8.de Cc: pbonzini@redhat.com Cc: tim.c.chen@linux.intel.com Cc: gregkh@linux-foundation.org Link: https://lkml.kernel.org/r/1517070274-12128-2-git-send-email-dwmw@amazon.co.uk
* x86/nospec: Fix header guards namesBorislav Petkov2018-01-261-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | ... to adhere to the _ASM_X86_ naming scheme. No functional change. Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: riel@redhat.com Cc: ak@linux.intel.com Cc: peterz@infradead.org Cc: David Woodhouse <dwmw2@infradead.org> Cc: jikos@kernel.org Cc: luto@amacapital.net Cc: dave.hansen@intel.com Cc: torvalds@linux-foundation.org Cc: keescook@google.com Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: tim.c.chen@linux.intel.com Cc: gregkh@linux-foundation.org Cc: pjt@google.com Link: https://lkml.kernel.org/r/20180126121139.31959-3-bp@alien8.de
* x86/speculation: Add basic IBPB (Indirect Branch Prediction Barrier) supportDavid Woodhouse2018-01-261-0/+13
| | | | | | | | | | | | | | | | | | | | | | | Expose indirect_branch_prediction_barrier() for use in subsequent patches. [ tglx: Add IBPB status to spectre_v2 sysfs file ] Co-developed-by: KarimAllah Ahmed <karahmed@amazon.de> Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Cc: gnomes@lxorguk.ukuu.org.uk Cc: ak@linux.intel.com Cc: ashok.raj@intel.com Cc: dave.hansen@intel.com Cc: arjan@linux.intel.com Cc: torvalds@linux-foundation.org Cc: peterz@infradead.org Cc: bp@alien8.de Cc: pbonzini@redhat.com Cc: tim.c.chen@linux.intel.com Cc: gregkh@linux-foundation.org Link: https://lkml.kernel.org/r/1516896855-7642-8-git-send-email-dwmw@amazon.co.uk
* x86/retpoline: Optimize inline assembler for vmexit_fill_RSBAndi Kleen2018-01-191-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | The generated assembler for the C fill RSB inline asm operations has several issues: - The C code sets up the loop register, which is then immediately overwritten in __FILL_RETURN_BUFFER with the same value again. - The C code also passes in the iteration count in another register, which is not used at all. Remove these two unnecessary operations. Just rely on the single constant passed to the macro for the iterations. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: David Woodhouse <dwmw@amazon.co.uk> Cc: dave.hansen@intel.com Cc: gregkh@linuxfoundation.org Cc: torvalds@linux-foundation.org Cc: arjan@linux.intel.com Link: https://lkml.kernel.org/r/20180117225328.15414-1-andi@firstfloor.org
* retpoline: Introduce start/end markers of indirect thunkMasami Hiramatsu2018-01-191-0/+3
| | | | | | | | | | | | | | | | | | | | Introduce start/end markers of __x86_indirect_thunk_* functions. To make it easy, consolidate .text.__x86.indirect_thunk.* sections to one .text.__x86.indirect_thunk section and put it in the end of kernel text section and adds __indirect_thunk_start/end so that other subsystem (e.g. kprobes) can identify it. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: David Woodhouse <dwmw@amazon.co.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/151629206178.10241.6828804696410044771.stgit@devbox
* x86/retpoline: Add LFENCE to the retpoline/RSB filling RSB macrosTom Lendacky2018-01-151-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The PAUSE instruction is currently used in the retpoline and RSB filling macros as a speculation trap. The use of PAUSE was originally suggested because it showed a very, very small difference in the amount of cycles/time used to execute the retpoline as compared to LFENCE. On AMD, the PAUSE instruction is not a serializing instruction, so the pause/jmp loop will use excess power as it is speculated over waiting for return to mispredict to the correct target. The RSB filling macro is applicable to AMD, and, if software is unable to verify that LFENCE is serializing on AMD (possible when running under a hypervisor), the generic retpoline support will be used and, so, is also applicable to AMD. Keep the current usage of PAUSE for Intel, but add an LFENCE instruction to the speculation trap for AMD. The same sequence has been adopted by GCC for the GCC generated retpolines. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@alien8.de> Acked-by: David Woodhouse <dwmw@amazon.co.uk> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Rik van Riel <riel@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Paul Turner <pjt@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org> Cc: Kees Cook <keescook@google.com> Link: https://lkml.kernel.org/r/20180113232730.31060.36287.stgit@tlendack-t1.amdoffice.net
* x86/retpoline: Fill return stack buffer on vmexitDavid Woodhouse2018-01-121-1/+77
| | | | | | | | | | | | | | | | | | | | | | | | | | | | In accordance with the Intel and AMD documentation, we need to overwrite all entries in the RSB on exiting a guest, to prevent malicious branch target predictions from affecting the host kernel. This is needed both for retpoline and for IBRS. [ak: numbers again for the RSB stuffing labels] Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: gnomes@lxorguk.ukuu.org.uk Cc: Rik van Riel <riel@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: thomas.lendacky@amd.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jikos@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Kees Cook <keescook@google.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org> Cc: Paul Turner <pjt@google.com> Link: https://lkml.kernel.org/r/1515755487-8524-1-git-send-email-dwmw@amazon.co.uk
* x86/spectre: Add boot time option to select Spectre v2 mitigationDavid Woodhouse2018-01-121-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a spectre_v2= option to select the mitigation used for the indirect branch speculation vulnerability. Currently, the only option available is retpoline, in its various forms. This will be expanded to cover the new IBRS/IBPB microcode features. The RETPOLINE_AMD feature relies on a serializing LFENCE for speculation control. For AMD hardware, only set RETPOLINE_AMD if LFENCE is a serializing instruction, which is indicated by the LFENCE_RDTSC feature. [ tglx: Folded back the LFENCE/AMD fixes and reworked it so IBRS integration becomes simple ] Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: gnomes@lxorguk.ukuu.org.uk Cc: Rik van Riel <riel@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: thomas.lendacky@amd.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jikos@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Kees Cook <keescook@google.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org> Cc: Paul Turner <pjt@google.com> Link: https://lkml.kernel.org/r/1515707194-20531-5-git-send-email-dwmw@amazon.co.uk
* x86/retpoline: Add initial retpoline supportDavid Woodhouse2018-01-121-0/+128
Enable the use of -mindirect-branch=thunk-extern in newer GCC, and provide the corresponding thunks. Provide assembler macros for invoking the thunks in the same way that GCC does, from native and inline assembler. This adds X86_FEATURE_RETPOLINE and sets it by default on all CPUs. In some circumstances, IBRS microcode features may be used instead, and the retpoline can be disabled. On AMD CPUs if lfence is serialising, the retpoline can be dramatically simplified to a simple "lfence; jmp *\reg". A future patch, after it has been verified that lfence really is serialising in all circumstances, can enable this by setting the X86_FEATURE_RETPOLINE_AMD feature bit in addition to X86_FEATURE_RETPOLINE. Do not align the retpoline in the altinstr section, because there is no guarantee that it stays aligned when it's copied over the oldinstr during alternative patching. [ Andi Kleen: Rename the macros, add CONFIG_RETPOLINE option, export thunks] [ tglx: Put actual function CALL/JMP in front of the macros, convert to symbolic labels ] [ dwmw2: Convert back to numeric labels, merge objtool fixes ] Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: gnomes@lxorguk.ukuu.org.uk Cc: Rik van Riel <riel@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: thomas.lendacky@amd.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jikos@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Kees Cook <keescook@google.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org> Cc: Paul Turner <pjt@google.com> Link: https://lkml.kernel.org/r/1515707194-20531-4-git-send-email-dwmw@amazon.co.uk
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