fix tls patch on windows (#328)

* fix tls patch on windows

based on TlsGetValue in kernel32.dll

* fix tls patch on windows for expansion slots
This commit is contained in:
Vinicius Rangel 2024-07-27 14:16:21 -03:00 committed by GitHub
parent 680192a0c4
commit 361412031c
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@ -285,20 +285,24 @@ static void GenerateTcbAccess(const ZydisDecodedOperand* operands, Xbyak::CodeGe
const auto slot = GetTcbKey();
#if defined(_WIN32)
// The following logic is based on the wine implementation of TlsGetValue
// https://github.com/wine-mirror/wine/blob/a27b9551/dlls/kernelbase/thread.c#L719
// The following logic is based on the Kernel32.dll asm of TlsGetValue
static constexpr u32 TlsSlotsOffset = 0x1480;
static constexpr u32 TlsExpansionSlotsOffset = 0x1780;
static constexpr u32 TlsMinimumAvailable = 64;
const u32 teb_offset = slot < TlsMinimumAvailable ? TlsSlotsOffset : TlsExpansionSlotsOffset;
const u32 tls_index = slot < TlsMinimumAvailable ? slot : slot - TlsMinimumAvailable;
// Load the pointer to the table of TLS slots.
c.putSeg(gs);
c.mov(dst, ptr[reinterpret_cast<void*>(teb_offset)]);
if (slot < TlsMinimumAvailable) {
// Load the pointer to TLS slots.
c.mov(dst, ptr[reinterpret_cast<void*>(TlsSlotsOffset + slot * sizeof(LPVOID))]);
} else {
const u32 tls_index = slot - TlsMinimumAvailable;
// Load the pointer to the table of TLS expansion slots.
c.mov(dst, ptr[reinterpret_cast<void*>(TlsExpansionSlotsOffset)]);
// Load the pointer to our buffer.
c.mov(dst, qword[dst + tls_index * sizeof(LPVOID)]);
}
#elif defined(__APPLE__)
// The following logic is based on the Darwin implementation of _os_tsd_get_direct, used by
// pthread_getspecific https://github.com/apple/darwin-xnu/blob/main/libsyscall/os/tsd.h#L89-L96