Re: Troubles with JIT compiler

[Scott Sibley <sisibley@xxxxxxxxx>]

On Fri, Jan 22, 2010 at 1:16 AM, Scott Sibley <sisibley@xxxxxxxxx> wrote:
> On Fri, Jan 22, 2010 at 1:01 AM, Robert Plantz <plantz@xxxxxxxxxx> wrote:
>> Very big oops here! See below.
>>
>>
>>> >>
>>> >> Well, it appears to be crashing at the first instruction. Here are the
>>> >> values of ebp and esp.
>>> >>
>>> >> (gdb) x/x $ebp
>>> >> 0xbffff168:    0xbffff188
>>> >> (gdb) x/x $esp
>>> >> 0xbffff14c:    0x0804e481
>>> >>
>>
>> I misread your gdb display. I'm used to using the i r command to look in
>> the registers.
>>
>> You used the x/x command, which shows the contents of the register, then
>> what it is pointing to.
>>
>> So the values in ebp and esp DO look reasonable. That's the range I
>> expect in 32-bit program, and they are reasonably close to each other.
>>
>> I apologize for my error.
>>
>> >From what you have posted, I don't see any problems with the first few
>> instructions. So I have no idea why the program is crashing there.
>>
>> Sorry...
>>
>> --Bob
>>
>>
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>
> Ah I see. Just for giggles here's the output of 'i r'
>
> (gdb) i r
> eax            0x8067888        134641800
> ecx            0xbffff07c       -1073745796
> edx            0x8067990        134642064
> ebx            0x970ff4 9900020
> esp            0xbffff14c       0xbffff14c
> ebp            0xbffff168       0xbffff168
> esi            0x0      0
> edi            0x0      0
> eip            0x8067990        0x8067990
> eflags         0x206    [ PF IF ]
> cs             0x73     115
> ss             0x7b     123
> ds             0x7b     123
> es             0x7b     123
> fs             0x0      0
> gs             0x33     51
>

After someone's tip, I found a solution to this. Passing the linker
'-z execstack' made it run, no problem. It's funny that Linux didn't
complain about it, but rather just seg-faulted.
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