This is a note to let you know that I've just added the patch titled
KVM: x86: Make indirect calls in emulator speculation safe
to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: kvm-x86-make-indirect-calls-in-emulator-speculation-safe.patch and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From foo@baz Fri Feb 23 17:23:58 CET 2018
From: Jack Wang jinpu.wang@profitbricks.com Date: Fri, 23 Feb 2018 11:41:52 +0100 Subject: KVM: x86: Make indirect calls in emulator speculation safe To: gregkh@linuxfoundation.org, stable@vger.kernel.org Cc: Peter Zijlstra peterz@infradead.org, Thomas Gleixner tglx@linutronix.de, Andrea Arcangeli aarcange@redhat.com, Andi Kleen ak@linux.intel.com, Ashok Raj ashok.raj@intel.com, Jun Nakajima jun.nakajima@intel.com, David Woodhouse dwmw2@infradead.org, Linus Torvalds torvalds@linux-foundation.org, rga@amazon.de, Dave Hansen dave.hansen@intel.com, Asit Mallick asit.k.mallick@intel.com, Andy Lutomirski luto@kernel.org, Josh Poimboeuf jpoimboe@redhat.com, Jason Baron jbaron@akamai.com, Paolo Bonzini pbonzini@redhat.com, Dan Williams dan.j.williams@intel.com, Arjan Van De Ven arjan.van.de.ven@intel.com, Tim Chen tim.c.chen@linux.intel.com, David Woodhouse dwmw@amazon.co.uk, Jack Wang jinpu.wang@profitbricks.com Message-ID: 1519382538-15143-4-git-send-email-jinpu.wangl@profitbricks.com
From: Peter Zijlstra peterz@infradead.org
(cherry picked from commit 1a29b5b7f347a1a9230c1e0af5b37e3e571588ab)
Replace the indirect calls with CALL_NOSPEC.
Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Signed-off-by: Thomas Gleixner tglx@linutronix.de Reviewed-by: David Woodhouse dwmw@amazon.co.uk Cc: Andrea Arcangeli aarcange@redhat.com Cc: Andi Kleen ak@linux.intel.com Cc: Ashok Raj ashok.raj@intel.com Cc: Greg KH gregkh@linuxfoundation.org Cc: Jun Nakajima jun.nakajima@intel.com Cc: David Woodhouse dwmw2@infradead.org Cc: Linus Torvalds torvalds@linux-foundation.org Cc: rga@amazon.de Cc: Dave Hansen dave.hansen@intel.com Cc: Asit Mallick asit.k.mallick@intel.com Cc: Andy Lutomirski luto@kernel.org Cc: Josh Poimboeuf jpoimboe@redhat.com Cc: Jason Baron jbaron@akamai.com Cc: Paolo Bonzini pbonzini@redhat.com Cc: Dan Williams dan.j.williams@intel.com Cc: Arjan Van De Ven arjan.van.de.ven@intel.com Cc: Tim Chen tim.c.chen@linux.intel.com Link: https://lkml.kernel.org/r/20180125095843.595615683@infradead.org [dwmw2: Use ASM_CALL_CONSTRAINT like upstream, now we have it] Signed-off-by: David Woodhouse dwmw@amazon.co.uk [backport to 4.4] Signed-off-by: Jack Wang jinpu.wang@profitbricks.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/kvm/emulate.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)
--- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -26,6 +26,7 @@ #include <asm/kvm_emulate.h> #include <linux/stringify.h> #include <asm/debugreg.h> +#include <asm/nospec-branch.h>
#include "x86.h" #include "tss.h" @@ -1000,8 +1001,8 @@ static u8 test_cc(unsigned int condition void (*fop)(void) = (void *)em_setcc + 4 * (condition & 0xf);
flags = (flags & EFLAGS_MASK) | X86_EFLAGS_IF; - asm("push %[flags]; popf; call *%[fastop]" - : "=a"(rc) : [fastop]"r"(fop), [flags]"r"(flags)); + asm("push %[flags]; popf; " CALL_NOSPEC + : "=a"(rc) : [thunk_target]"r"(fop), [flags]"r"(flags)); return rc; }
@@ -5297,9 +5298,9 @@ static int fastop(struct x86_emulate_ctx ulong flags = (ctxt->eflags & EFLAGS_MASK) | X86_EFLAGS_IF; if (!(ctxt->d & ByteOp)) fop += __ffs(ctxt->dst.bytes) * FASTOP_SIZE; - asm("push %[flags]; popf; call *%[fastop]; pushf; pop %[flags]\n" + asm("push %[flags]; popf; " CALL_NOSPEC "; pushf; pop %[flags]\n" : "+a"(ctxt->dst.val), "+d"(ctxt->src.val), [flags]"+D"(flags), - [fastop]"+S"(fop) + [thunk_target]"+S"(fop) : "c"(ctxt->src2.val)); ctxt->eflags = (ctxt->eflags & ~EFLAGS_MASK) | (flags & EFLAGS_MASK); if (!fop) /* exception is returned in fop variable */
Patches currently in stable-queue which might be from jinpu.wang@profitbricks.com are
queue-4.4/x86-paravirt-remove-noreplace-paravirt-cmdline-option.patch queue-4.4/documentation-document-array_index_nospec.patch queue-4.4/kvm-x86-make-indirect-calls-in-emulator-speculation-safe.patch queue-4.4/x86-nospec-fix-header-guards-names.patch queue-4.4/x86-retpoline-avoid-retpolines-for-built-in-__init-functions.patch queue-4.4/vfs-fdtable-prevent-bounds-check-bypass-via-speculative-execution.patch queue-4.4/kvm-nvmx-invvpid-handling-improvements.patch queue-4.4/x86-cpu-bugs-make-retpoline-module-warning-conditional.patch queue-4.4/x86-spectre-check-config_retpoline-in-command-line-parser.patch queue-4.4/x86-implement-array_index_mask_nospec.patch queue-4.4/array_index_nospec-sanitize-speculative-array-de-references.patch queue-4.4/kvm-vmx-make-indirect-call-speculation-safe.patch queue-4.4/x86-spectre-fix-spelling-mistake-vunerable-vulnerable.patch queue-4.4/kvm-nvmx-fix-kernel-panics-induced-by-illegal-invept-invvpid-types.patch queue-4.4/module-retpoline-warn-about-missing-retpoline-in-module.patch queue-4.4/x86-kvm-update-spectre-v1-mitigation.patch queue-4.4/x86-get_user-use-pointer-masking-to-limit-speculation.patch queue-4.4/x86-syscall-sanitize-syscall-table-de-references-under-speculation.patch queue-4.4/kvm-nvmx-vmx_complete_nested_posted_interrupt-can-t-fail.patch queue-4.4/x86-spectre-simplify-spectre_v2-command-line-parsing.patch queue-4.4/x86-speculation-fix-typo-ibrs_att-which-should-be-ibrs_all.patch queue-4.4/x86-spectre-report-get_user-mitigation-for-spectre_v1.patch queue-4.4/x86-introduce-barrier_nospec.patch queue-4.4/kvm-async_pf-fix-df-due-to-inject-page-not-present-and-page-ready-exceptions-simultaneously.patch queue-4.4/kvm-vmx-clean-up-declaration-of-vpid-ept-invalidation-types.patch queue-4.4/x86-bugs-drop-one-mitigation-from-dmesg.patch queue-4.4/x86-retpoline-remove-the-esp-rsp-thunk.patch queue-4.4/nl80211-sanitize-array-index-in-parse_txq_params.patch queue-4.4/kvm-nvmx-kmap-can-t-fail.patch