I noticed that happening in the syscall stubs as well. Could you open  
up a bug report on the website so thath we'll make sure and get this  
handled at some point?

Thanks,

Ali

On Dec 16, 2008, at 6:09 PM, Jack Whitham wrote:

> On Tue, Dec 16, 2008 at 04:51:55PM -0500, [email protected] wrote:
>> Thank you for pointing this out. I can't look at this in detail at  
>> the moment,
>> but what probably should be changed is the part of getSyscallArg  
>> that the ISA
>> provides. It should probably truncate the register values as  
>> they're retrieved
>> for the system call emulation function if it's from a 32 bit  
>> application. I'll
>> try to look at this more closely soon to give you a more definitive  
>> answer and
>> hopefully a patch.
>
> Thanks very much for your response. This fix sounds like the right  
> thing.
> I'm in no hurry for an official fix, because I have written a  
> temporary
> hack to fix it, but it will break 64 bit SPARC applications so it's no
> use to you.
>
> However, when you do have time to look at this problem, I think I may
> have found a related issue. Values *returned* by system calls should  
> *also*
> be truncated for 32 bit applications, when M5 has been compiled for  
> x86_64.
>
> Here, for example, are two instructions that are run immediately after
> the lseek system call completes. This is a diff of two traces from the
> same program, one produced on a 64 bit machine (<) and the other
> produced on a 32 bit machine (>). The system call has left some data  
> in
> the top 32 bits (in %o0).
>
> 60842,60843c60842,60843
> < 30466500: system.cpu T0 : @__libc_lseek+40 :  mov   %o0, %i0
> : IntAlu :  D=0x00c4c5bc00bcc5c4
> < 30467000: system.cpu T0 : @__libc_lseek+48 :  add   %i0, 0xff, %g1
> : IntAlu :  D=0x00c4c5bc00bcc6c3
> ---
>> 30466500: system.cpu T0 : @__libc_lseek+40 :  mov   %o0, %i0
>> : IntAlu :  D=0x0000000000bcc5c4
>> 30467000: system.cpu T0 : @__libc_lseek+48 :  add   %i0, 0xff, %g1
>> : IntAlu :  D=0x0000000000bcc6c3
>
>
>
> -- 
> Jack Whitham
> [email protected]
>
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> m5-users mailing list
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> http://m5sim.org/cgi-bin/mailman/listinfo/m5-users
>

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