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 4.14-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: x86entry64_Push_extra_regs_right_away.patch and it can be found in the queue-4.14 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.

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

From: Andy Lutomirski luto@kernel.org

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: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- arch/x86/entry/entry_64.S | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)

--- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -232,13 +232,17 @@ GLOBAL(entry_SYSCALL_64_after_hwframe) 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 */ - UNWIND_HINT_REGS extra=0 + 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 */ + UNWIND_HINT_REGS

TRACE_IRQS_OFF

/* 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-4.14/objtool_Add_support_for_alternatives_at_the_end_of_a_section.patch queue-4.14/x86pti_Mark_constant_arrays_as___initconst.patch queue-4.14/x86speculation_Use_Indirect_Branch_Prediction_Barrier_in_context_switch.patch queue-4.14/x86spectre_Fix_spelling_mistake_vunerable-_vulnerable.patch queue-4.14/x86get_user_Use_pointer_masking_to_limit_speculation.patch queue-4.14/x86paravirt_Remove_noreplace-paravirt_cmdline_option.patch queue-4.14/KVM_VMX_Make_indirect_call_speculation_safe.patch queue-4.14/KVMVMX_Allow_direct_access_to_MSR_IA32_SPEC_CTRL.patch queue-4.14/x86entry64_Remove_the_SYSCALL64_fast_path.patch queue-4.14/KVMSVM_Allow_direct_access_to_MSR_IA32_SPEC_CTRL.patch queue-4.14/x86asm_Move_status_from_thread_struct_to_thread_info.patch queue-4.14/KVMx86_Add_IBPB_support.patch queue-4.14/KVMVMX_Emulate_MSR_IA32_ARCH_CAPABILITIES.patch queue-4.14/KVM_x86_Make_indirect_calls_in_emulator_speculation_safe.patch queue-4.14/x86entry64_Push_extra_regs_right_away.patch queue-4.14/objtool_Warn_on_stripped_section_symbol.patch queue-4.14/x86syscall_Sanitize_syscall_table_de-references_under_speculation.patch queue-4.14/objtool_Improve_retpoline_alternative_handling.patch