Hello,
I decided to try once more with a follow-up email, since my previous one got no
responses (I hope itโs not considered rude to send more than one message in a
row for a particular question).
To sum up and clarify my previous question, what I need is a way to track
memory stores and save both the old and the new value of the memory location
being modified.
My thinking so far:
Recognize the instructions that definitely access memory before they execute,
based on their opcode.
Tell whether each operand is a register or a memory location.
If itโs a memory location, check whether it is a load or store destination.
In case it is a store destination, fetch and save current value from memory.
Execute instruction.
Fetch and save new value from memory.
However, I was not able to find a cross-architecture API that covers all of the
conditions above and more specifically Instruction::DoesStore() and
Operand::IsStoreDestination().
Last but not least, I should notice that the target is executed in single-step
mode, so I do have control right before and after the execution of every
instruction.
Thanks, again, in advance! ๐
โ Vangelis
> On 21 Oct 2019, at 08:54, Vangelis Tsiatsianas wrote:
>
> Hello,
>
> I am looking for a way to identify loads, stores and any other kind of
> instruction that definitely perform memory access and extract the address
> operand(s), however I was not able to find a cross-architecture API. The
> closest I stumbled upon are "MCInstrDesc::mayLoad()" and
> "MCInstrDesc::mayStore()", but I understand that their results are just a
> hint, so I would then need to examine the instruction name or opcode in order
> to find out whether itโs actually a load or store and which operand(s) is
> (are) memory address(es) and also do so for each architecture separately,
> which I would really like to avoid.
>
> Is there a way to identify such instructions either by examining them through
> the disassembler (e.g. "DoesLoad()" | "DoesStore()") before they execute or
> right after they perform any kind of memory access?
>
> Thank you very much, in advance! ๐
>
>
> โ Vangelis
>
>
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