11787 Kernel needs to be built with retpolines
11788 Kernel needs to generally use RSB stuffing
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>
Reviewed by: John Levon <john.levon@joyent.com>

*** 753,763 ****
  
  #if defined(__amd64)
  
          ENTRY_NP(i86_mwait)
          pushq   %rbp
!         call    *x86_md_clear
          movq    %rsp, %rbp
          movq    %rdi, %rax              /* data */
          movq    %rsi, %rcx              /* extensions */
          .byte   0x0f, 0x01, 0xc9        /* mwait */
          leave
--- 753,763 ----
  
  #if defined(__amd64)
  
          ENTRY_NP(i86_mwait)
          pushq   %rbp
!         call    x86_md_clear
          movq    %rsp, %rbp
          movq    %rdi, %rax              /* data */
          movq    %rsi, %rcx              /* extensions */
          .byte   0x0f, 0x01, 0xc9        /* mwait */
          leave
*** 2558,2568 ****
          addq    %rdi, %rsi
          leaq    .ip_ocsum_jmptbl(%rip), %rdi
          leaq    (%rdi, %rcx, 8), %rdi
          xorl    %ecx, %ecx
          clc
!         jmp     *(%rdi)
  
          .align  8
  .ip_ocsum_jmptbl:
          .quad   .only0, .only4, .only8, .only12, .only16, .only20
          .quad   .only24, .only28, .only32, .only36, .only40, .only44
--- 2558,2569 ----
          addq    %rdi, %rsi
          leaq    .ip_ocsum_jmptbl(%rip), %rdi
          leaq    (%rdi, %rcx, 8), %rdi
          xorl    %ecx, %ecx
          clc
!         movq    (%rdi), %rdi
!         INDIRECT_JMP_REG(rdi)
  
          .align  8
  .ip_ocsum_jmptbl:
          .quad   .only0, .only4, .only8, .only12, .only16, .only20
          .quad   .only24, .only28, .only32, .only36, .only40, .only44
*** 3608,3618 ****
           * We need to call *gethrtimef before picking up CLOCK_LOCK (obviously,
           * hres_last_tick can only be modified while holding CLOCK_LOCK).
           * At worst, performing this now instead of under CLOCK_LOCK may
           * introduce some jitter in pc_gethrestime().
           */
!         call    *gethrtimef(%rip)
          movq    %rax, %r8
  
          leaq    hres_lock(%rip), %rax
          movb    $-1, %dl
  .CL1:
--- 3609,3620 ----
           * We need to call *gethrtimef before picking up CLOCK_LOCK (obviously,
           * hres_last_tick can only be modified while holding CLOCK_LOCK).
           * At worst, performing this now instead of under CLOCK_LOCK may
           * introduce some jitter in pc_gethrestime().
           */
!         movq    gethrtimef(%rip), %rsi
!         INDIRECT_CALL_REG(rsi)
          movq    %rax, %r8
  
          leaq    hres_lock(%rip), %rax
          movb    $-1, %dl
  .CL1:
*** 4088,4098 ****
          movq    %rsp, %rbp              /* set up stack frame */
          movq    %rdi, %rsp              /* switch stack pointer */
          movq    %rdx, %rdi              /* pass func arg 1 */
          movq    %rsi, %r11              /* save function to call */
          movq    %rcx, %rsi              /* pass func arg 2 */
!         call    *%r11                   /* call function */
          leave                           /* restore stack */
          ret
          SET_SIZE(switch_sp_and_call)
  
  #elif defined(__i386)
--- 4090,4100 ----
          movq    %rsp, %rbp              /* set up stack frame */
          movq    %rdi, %rsp              /* switch stack pointer */
          movq    %rdx, %rdi              /* pass func arg 1 */
          movq    %rsi, %r11              /* save function to call */
          movq    %rcx, %rsi              /* pass func arg 2 */
!         INDIRECT_CALL_REG(r11)          /* call function */
          leave                           /* restore stack */
          ret
          SET_SIZE(switch_sp_and_call)
  
  #elif defined(__i386)