Re: kernel: supervisor trap asynchronous system trap, code=0

[yamt%mwd.biglobe.ne.jp@localhost (YAMAMOTO Takashi)]

> Index: i386/locore.S
> ===================================================================
> RCS file: /cvsroot/src/sys/arch/xen/i386/locore.S,v
> retrieving revision 1.25
> diff -u -r1.25 locore.S
> --- i386/locore.S     17 May 2007 14:51:35 -0000      1.25
> +++ i386/locore.S     28 Jun 2007 13:27:49 -0000
> @@ -663,6 +663,7 @@
>        * Switch to newlwp's stack.
>        */
>  
> +     CLI(%ebx)
>       movl    L_ADDR(%edi),%ebx
>       movl    PCB_EBP(%ebx),%ebp
>       movl    PCB_ESP(%ebx),%esp

can you explain why it's necessary?

anyway, please don't call ras_lookup with interrupt disabled.

> @@ -780,9 +789,29 @@
>       call    _C_LABEL(trap)
>       addl    $4,%esp
>       jmp     .Lsyscall_checkast
> -1:   STI(%eax)
> -     CHECK_DEFERRED_SWITCH(%eax)
> +1:   CHECK_DEFERRED_SWITCH(%eax)
>       jnz     9f
> +     STIC(%eax)
> +     jz      14f
> +     call    _C_LABEL(stipending)
> +     testl   %eax,%eax
> +     jz      14f
> +     /* process pending interrupts */
> +     CLI(%eax)
> +     movl    CPUVAR(ILEVEL), %ebx
> +     movl    $.Lsyscall_resume, %esi # address to resume loop at
> +.Lsyscall_resume:
> +     movl    %ebx,%eax               # get cpl
> +     movl    CPUVAR(IUNMASK)(,%eax,4),%eax
> +     andl    CPUVAR(IPENDING),%eax   # any non-masked bits left?
> +     jz      17f
> +     bsrl    %eax,%eax
> +     btrl    %eax,CPUVAR(IPENDING)
> +     movl    CPUVAR(ISOURCES)(,%eax,4),%eax
> +     jmp     *IS_RESUME(%eax)
> +17:  movl    %ebx, CPUVAR(ILEVEL)    #restore cpl
> +     jmp     .Lsyscall_checkast
> +14:
>  #ifndef DIAGNOSTIC
>       INTRFASTEXIT
>  #else /* DIAGNOSTIC */

can't these duplicated code be shared?

i'm not sure why stipending() was needed in the first place,
in addition to __sti() and do_hypervisor_callback().

YAMAMOTO Takashi