how do u declare and initialize and array of NOPs?
__asm__ __volatile__(".byte 0x90") or __asm__ __volatile__("nop")
like this?
void (*func_ptr[4])(void) {
&Test_nops,
&Test_nops,
&Test_nops,
&Test_nops
};
void Test_Nops(void) {
__asm__ __volatile__("nop");
return;
};
2) It shows Zen_cores has 2-sets of 4-wide Decoders. (is it on a per core basis?, that's 1 core 8 decoders) hence if i got a 8-cores CPU (say the X3D, then in totality my CPU have 8*8==64 decoders
Fill opcodes into the array, just like filling any normal array. Then use whatever OS call you need to make it executable and jump to it. Make sure you have a return at the end of the array.
My code has
for (uint64_t nopIdx = 0; nopIdx < elements; nopIdx++)
nops[nopIdx] = *nop8bptr;
where nop8ptr started out pointing to a 8B NOP at first, but I've hacked a lot of other things in since so it's no longer recognizable.
then mprotect((void *)nopfuncPage, mprotectLen, PROT_EXEC | PROT_READ | PROT_WRITE) or VirtualAlloc(..., MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE) on Windows, and jump to it from a function pointer
Dumb questions..
how do u declare and initialize and array of NOPs?
__asm__ __volatile__(".byte 0x90") or __asm__ __volatile__("nop")
like this?
void (*func_ptr[4])(void) {
&Test_nops,
&Test_nops,
&Test_nops,
&Test_nops
};
void Test_Nops(void) {
__asm__ __volatile__("nop");
return;
};
2) It shows Zen_cores has 2-sets of 4-wide Decoders. (is it on a per core basis?, that's 1 core 8 decoders) hence if i got a 8-cores CPU (say the X3D, then in totality my CPU have 8*8==64 decoders
Fill opcodes into the array, just like filling any normal array. Then use whatever OS call you need to make it executable and jump to it. Make sure you have a return at the end of the array.
My code has
for (uint64_t nopIdx = 0; nopIdx < elements; nopIdx++)
nops[nopIdx] = *nop8bptr;
where nop8ptr started out pointing to a 8B NOP at first, but I've hacked a lot of other things in since so it's no longer recognizable.
then mprotect((void *)nopfuncPage, mprotectLen, PROT_EXEC | PROT_READ | PROT_WRITE) or VirtualAlloc(..., MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE) on Windows, and jump to it from a function pointer
And yes, decoders are per-core