I'm not really experienced with x86 assembler and try to debug a problem related to a bug in mach_inject.
The original code looks like this (function mach_inject
in mach_inject.c):
#if defined(__开发者_开发技巧x86_64__)
imageOffset = 0; // RIP-relative addressing
#else
ASSERT_CAST( void*, remoteCode );
imageOffset = ((void*) remoteCode) - image;
#endif
and then somewhat later (function INJECT_ENTRY
of mach_inject_bundle_stub.c):
pthread_create( &thread,
&attr,
(void* (*)(void*))((long)some_local_function + imageOffset),
(void*) param );
It seems, for me, when I compile this for x86, it fails. If I change the code so that I have imageOffset = 0;
on just every architecture (i.e. also for x86), it all works fine.
So, some questions:
- RIP-relative addressing is also available for 32bit/x86 mode?
- What was (probably) the initial intention for this code if we anyway have also RIP-relative addressing for 32bit mode?
- Is RIP-relative addressing a compiler setting? Or in what way can I control if my code uses RIP-relative addressing or not? (Or more related to this bug: Is
imageOffset = 0;
always correct? Or when is it not?)
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