OS-3735 modstubs MAXNARG is too low.

*** 48,58 ****
   *      but worth it?!).
   *
   *      NOTE: Use NO_UNLOAD_STUBs if the module is NOT unloadable once it is
   *            loaded.
   */
! #define MAXNARG 10
  
  /*
   * WARNING: there is no check for forgetting to write END_MODULE,
   * and if you do, the kernel will most likely crash.  Be careful
   *
--- 48,58 ----
   *      but worth it?!).
   *
   *      NOTE: Use NO_UNLOAD_STUBs if the module is NOT unloadable once it is
   *            loaded.
   */
! #define MAXNARG 12
  
  /*
   * WARNING: there is no check for forgetting to write END_MODULE,
   * and if you do, the kernel will most likely crash.  Be careful
   *
*** 182,192 ****
          pushq   %rsi
          pushq   %rdx
          pushq   %rcx
          pushq   %r8
          pushq   %r9
!         /* (next 4 args, if any, are already on the stack above %rbp) */
          movq    %r15, %rdi
          call    mod_hold_stub           /* mod_hold_stub(mod_stub_info *) */
          cmpl    $-1, %eax               /* error? */
          jne     .L1
          movq    0x18(%r15), %rax
--- 182,192 ----
          pushq   %rsi
          pushq   %rdx
          pushq   %rcx
          pushq   %r8
          pushq   %r9
!         /* (next 6 args, if any, are already on the stack above %rbp) */
          movq    %r15, %rdi
          call    mod_hold_stub           /* mod_hold_stub(mod_stub_info *) */
          cmpl    $-1, %eax               /* error? */
          jne     .L1
          movq    0x18(%r15), %rax
*** 193,203 ****
          call    *%rax
          addq    $0x30, %rsp
          jmp     .L2
  .L1:
          /*
!          * copy MAXNARG == 10 incoming arguments
           */
          popq    %r9
          popq    %r8
          popq    %rcx
          popq    %rdx
--- 193,203 ----
          call    *%rax
          addq    $0x30, %rsp
          jmp     .L2
  .L1:
          /*
!          * copy MAXNARG == 12 incoming arguments
           */
          popq    %r9
          popq    %r8
          popq    %rcx
          popq    %rdx
*** 217,228 ****
          movl    $MAXNARG - 6 + 3, %r11d
          pushq   (%rsp, %r11, 8)
          pushq   (%rsp, %r11, 8)
          pushq   (%rsp, %r11, 8)
          pushq   (%rsp, %r11, 8)
          call    *(%r15)                 /* call the stub fn(arg, ..) */
!         addq    $0x20, %rsp             /* pop off last 4 args */
          pushq   %rax                    /* save any return values */
          pushq   %rdx
          movq    %r15, %rdi
          call    mod_release_stub        /* release hold on module */
          popq    %rdx                    /* restore return values */
--- 217,230 ----
          movl    $MAXNARG - 6 + 3, %r11d
          pushq   (%rsp, %r11, 8)
          pushq   (%rsp, %r11, 8)
          pushq   (%rsp, %r11, 8)
          pushq   (%rsp, %r11, 8)
+         pushq   (%rsp, %r11, 8)
+         pushq   (%rsp, %r11, 8)
          call    *(%r15)                 /* call the stub fn(arg, ..) */
!         addq    $0x30, %rsp             /* pop off last 6 args */
          pushq   %rax                    /* save any return values */
          pushq   %rdx
          movq    %r15, %rdi
          call    mod_release_stub        /* release hold on module */
          popq    %rdx                    /* restore return values */
*** 336,345 ****
--- 338,349 ----
          movl    $MAXNARG+1, %ecx
          / copy incoming arguments
          pushl   (%esp, %ecx, 4)         / push MAXNARG times
          pushl   (%esp, %ecx, 4)
          pushl   (%esp, %ecx, 4)
+         pushl   (%esp, %ecx, 4)
+         pushl   (%esp, %ecx, 4)
          pushl   (%esp, %ecx, 4)
          pushl   (%esp, %ecx, 4)
          pushl   (%esp, %ecx, 4)
          pushl   (%esp, %ecx, 4)
          pushl   (%esp, %ecx, 4)