This is a note to let you know that I've just added the patch titled

x86/entry/64: Push extra regs right away

to the 4.9-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: x86-entry-64-push-extra-regs-right-away.patch and it can be found in the queue-4.9 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 Thu Feb 8 03:30:27 CET 2018

From: Andy Lutomirski luto@kernel.org Date: Sun, 28 Jan 2018 10:38:49 -0800 Subject: x86/entry/64: Push extra regs right away

From: Andy Lutomirski luto@kernel.org

(cherry picked from commit d1f7732009e0549eedf8ea1db948dc37be77fd46)

With the fast path removed there is no point in splitting the push of the normal and the extra register set. Just push the extra regs right away.

[ tglx: Split out from 'x86/entry/64: Remove the SYSCALL64 fast path' ]

Signed-off-by: Andy Lutomirski luto@kernel.org Signed-off-by: Thomas Gleixner tglx@linutronix.de Acked-by: Ingo Molnar mingo@kernel.org Cc: Borislav Petkov bp@alien8.de Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Kernel Hardening kernel-hardening@lists.openwall.com Link: https://lkml.kernel.org/r/462dff8d4d64dfbfc851fbf3130641809d980ecd.151716446... Signed-off-by: David Woodhouse dwmw@amazon.co.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/entry/entry_64.S | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)

--- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -177,10 +177,14 @@ GLOBAL(entry_SYSCALL_64_after_swapgs) pushq %r9 /* pt_regs->r9 */ pushq %r10 /* pt_regs->r10 */ pushq %r11 /* pt_regs->r11 */ - sub $(6*8), %rsp /* pt_regs->bp, bx, r12-15 not saved */ + pushq %rbx /* pt_regs->rbx */ + pushq %rbp /* pt_regs->rbp */ + pushq %r12 /* pt_regs->r12 */ + pushq %r13 /* pt_regs->r13 */ + pushq %r14 /* pt_regs->r14 */ + pushq %r15 /* pt_regs->r15 */

/* IRQs are off. */ - SAVE_EXTRA_REGS movq %rsp, %rdi call do_syscall_64 /* returns with IRQs disabled */

Patches currently in stable-queue which might be from luto@kernel.org are

queue-4.9/x86-entry-64-push-extra-regs-right-away.patch queue-4.9/kvm-vmx-allow-direct-access-to-msr_ia32_spec_ctrl.patch queue-4.9/kvm-x86-add-ibpb-support.patch queue-4.9/kvm-svm-allow-direct-access-to-msr_ia32_spec_ctrl.patch queue-4.9/x86-paravirt-remove-noreplace-paravirt-cmdline-option.patch queue-4.9/x86-asm-move-status-from-thread_struct-to-thread_info.patch queue-4.9/kvm-x86-make-indirect-calls-in-emulator-speculation-safe.patch queue-4.9/x86-entry-64-remove-the-syscall64-fast-path.patch queue-4.9/x86-asm-fix-inline-asm-call-constraints-for-gcc-4.4.patch queue-4.9/kvm-vmx-make-indirect-call-speculation-safe.patch queue-4.9/x86-spectre-fix-spelling-mistake-vunerable-vulnerable.patch queue-4.9/x86-get_user-use-pointer-masking-to-limit-speculation.patch queue-4.9/x86-syscall-sanitize-syscall-table-de-references-under-speculation.patch queue-4.9/x86-pti-make-unpoison-of-pgd-for-trusted-boot-work-for-real.patch queue-4.9/x86-pti-mark-constant-arrays-as-__initconst.patch queue-4.9/kvm-vmx-emulate-msr_ia32_arch_capabilities.patch