On 11/18/2013 03:47 AM, Mischa Baars wrote:
> On 11/17/2013 11:05 PM, Florian Weimer wrote:
>> * Mischa Baars:
>>
>>> Please have a look at the following example, and let me know what
>>> you think.
>> The code doesn't contain any comments, so we don't know what you're
>> trying to do.
>
> The assembly file does, if you would just look at it.
>
> As you can see, the 'ebx' register is unprotected when the function is
> called from a location other than 'main'. Normally I shouldn't be able
> to modify the array index from the assembly.
You're doing it wrong. It is the job of the called function to save and
restore %ebx:
%ebx As described below, this register serves as the global offset
table base register for position-independent code. For
absolute code, %ebx serves as a local register and has no
specified role in the function calling sequence. In either
case, a function must preserve the register value for the
caller.
Andrew.
http://www.sco.com/developers/devspecs/abi386-4.pdf
