Fix compilation on older systems

Cherry-pick upstream commit f97ca48b1cbbf5da065e94271cb3af4f1c907dd4.

Fixes https://bugs.llvm.org/show_bug.cgi?id=47896

diff --git a/libsanitizer/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cpp b/libsanitizer/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cpp
index 6a3c00458efb435b63d439f30b1305449d63e6b3..eb89f1fddc5be2180cc1cc3d756a397ea4d8b582 100644 (file)
--- a/libsanitizer/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cpp
+++ b/libsanitizer/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cpp
@@ -486,6 +486,10 @@ typedef user_regs_struct regs_struct;
 #define REG_SP rsp
 #endif
 #define ARCH_IOVEC_FOR_GETREGSET
+// Support ptrace extensions even when compiled without required kernel support
+#ifndef NT_X86_XSTATE
+#define NT_X86_XSTATE 0x202
+#endif
 // Compiler may use FP registers to store pointers.
 static constexpr uptr kExtraRegs[] = {NT_X86_XSTATE, NT_FPREGSET};