[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?
cheers,
dalibor topic
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