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Merge pull request #1975 from CookiePLMonster/CC-005-rdtsc-false-positive 

Add an rdtsc false positive check for Group S Challenge [CC-005] [1.05]
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Luke Usher 2020-10-06 10:11:06 +01:00 committed by GitHub
parent a852c3ef9d 0a46366c22
commit f8e0b73e23
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1 changed files with 10 additions and 1 deletions
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11
src/core/kernel/init/CxbxKrnl.cpp
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@ -492,7 +492,7 @@ const uint8_t rdtsc_pattern[] = {
0xEB,
0xF6,
0xA1,
0x01
0x01 // one false positive in Group S Challenge [1.05] .text E8 0F 31 01 00
};
const int sizeof_rdtsc_pattern = sizeof(rdtsc_pattern);
@ -550,6 +550,15 @@ void PatchRdtscInstructions()
continue;
}
}
if (next_byte == 0x01)
{
if (*(uint8_t*)(addr - 1) == 0xE8 && *(uint8_t*)(addr + 3) == 0x00)
{
EmuLogInit(LOG_LEVEL::INFO, "Skipped false positive: rdtsc pattern 0x%.2X, @ 0x%.8X", next_byte, (DWORD)addr);
continue;
}
}
PatchRdtsc(addr);
//the first for loop already increment addr per loop. we only increment one more time so the addr will point to the byte next to the found rdtsc instruction. this is important since there is at least one case that two rdtsc instructions are next to each other.