[kaffe] mipsel and jit3

Dalibor Topic robilad at kaffe.org
Mon Oct 11 21:10:22 PDT 2004

Mikolaj Habryn wrote:
> On Sat, 2004-10-09 at 12:54, Mikolaj Habryn wrote:
>>And, and... how exactly did that method get JITted in 0 ms? Something
>>very, very fishy here.
> Well, it's a null method, that's how. I'm about puzzled out for one day.
> Turning on various bits of debug and sprinkling in some dprintfs yields
> this output just before crashing:
>   Method Constant Pool:
>   10093da8: (ref) 0x1006baf4      0x1006baf4
>   10093db0: (ref) 0x2ab51f28      0x2ab51f28
>   10093db8: (ref) 0x2ab51e40      0x2ab51e40
>   10093dc0: (ref) 0x1005e2b8      0x1005e2b8
>   set jitted for method 0x1006baf4 to 0x10093dc8
>   Translating java/lang/String$ICComp.<init>()V (normal) 0x10093dc8
>   <JIT: java/lang/String$ICComp.<init>()V time 44ms (220ms) @ 0x10093dc8 (0x1006baf4)>
>   soft_fixup_trampoline(): return 0x10093dc8
>   soft_fixup_trampoline(): meth 0x1005e2a4, where 0x1005e2b8, native code 0x1005e2b8
>   callinfo = 0x7fff7590
>   null call?? 0x1005e2a4 going to soft_null_call 0x2ab50a50
>   called soft_null_call (0x2ab50a50), seemed to work
>   set native for method 0x1005e2a4 to 0x2ab50a50
>   Translating java/lang/Object.<init>()V (normal) 0x2ab50a50
>   <JIT: java/lang/Object.<init>()V time 15ms (235ms) @ 0x2ab50a50 (0x1005e2a4)>
>   soft_fixup_trampoline(): return 0x2ab50a50
>   Illegal instruction (core dumped)
>   root at OpenWrt:~#
> The crash is an illegal instruction at 0x1005e2b0. Disassembling the
> region shows:
> 0x1005e2a4:     beq     zero,v0,0x1006a708
> 0x1005e2a8:     b       0x1007afac
> 0x1005e2ac:     0xc801
> 0x1005e2b0:     sdc3    $31,-1(ra)
> 0x1005e2b4:     sll     zero,at,0x0
> 0x1005e2b8:     slti    s5,s5,2640
> Which makes me suspect that it's actually dying at 0x1005e2ac but
> advancing the PC nonetheless. Or something. Anyway. From the first
> snippet, you can see that there's something from some previous method's
> constant pool right after that point, at 0x1005e2b8, and the previous
> method block itself (?) just before it, at 0x1005e2a4.
> So, how did we wind up jumping to that address? Broken trampoline?

Hi Mikolaj,

Sounds like a good guess. Could you reconfigure and try again using libffi?

dalibor topic

More information about the kaffe mailing list