+SyscallReturn
+cloneFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
+ ThreadContext *tc)
+{
+ int index = 0;
+ IntReg flags = process->getSyscallArg(tc, index);
+ IntReg newStack = process->getSyscallArg(tc, index);
+
+ DPRINTF(SyscallVerbose, "In sys_clone:\n");
+ DPRINTF(SyscallVerbose, " Flags=%llx\n", flags);
+ DPRINTF(SyscallVerbose, " Child stack=%llx\n", newStack);
+
+
+ if (flags != 0x10f00) {
+ warn("This sys_clone implementation assumes flags "
+ "CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND|CLONE_THREAD "
+ "(0x10f00), and may not work correctly with given flags "
+ "0x%llx\n", flags);
+ }
+
+ ThreadContext* ctc; // child thread context
+ if ( ( ctc = process->findFreeContext() ) != NULL ) {
+ DPRINTF(SyscallVerbose, " Found unallocated thread context\n");
+
+ ctc->clearArchRegs();
+
+ // Arch-specific cloning code
+ #if THE_ISA == ALPHA_ISA or THE_ISA == X86_ISA
+ // Cloning the misc. regs for these archs is enough
+ TheISA::copyMiscRegs(tc, ctc);
+ #elif THE_ISA == SPARC_ISA
+ TheISA::copyRegs(tc, ctc);
+
+ // TODO: Explain what this code actually does :-)
+ ctc->setIntReg(NumIntArchRegs + 6, 0);
+ ctc->setIntReg(NumIntArchRegs + 4, 0);
+ ctc->setIntReg(NumIntArchRegs + 3, NWindows - 2);
+ ctc->setIntReg(NumIntArchRegs + 5, NWindows);
+ ctc->setMiscReg(MISCREG_CWP, 0);
+ ctc->setIntReg(NumIntArchRegs + 7, 0);
+ ctc->setMiscRegNoEffect(MISCREG_TL, 0);
+ ctc->setMiscRegNoEffect(MISCREG_ASI, ASI_PRIMARY);
+
+ for (int y = 8; y < 32; y++)
+ ctc->setIntReg(y, tc->readIntReg(y));
+ #elif THE_ISA == ARM_ISA
+ TheISA::copyRegs(tc, ctc);
+ #else
+ fatal("sys_clone is not implemented for this ISA\n");
+ #endif
+
+ // Set up stack register
+ ctc->setIntReg(TheISA::StackPointerReg, newStack);
+
+ // Set up syscall return values in parent and child
+ ctc->setIntReg(ReturnValueReg, 0); // return value, child
+
+ // Alpha needs SyscallSuccessReg=0 in child
+ #if THE_ISA == ALPHA_ISA
+ ctc->setIntReg(TheISA::SyscallSuccessReg, 0);
+ #endif
+
+ // In SPARC/Linux, clone returns 0 on pseudo-return register if
+ // parent, non-zero if child
+ #if THE_ISA == SPARC_ISA
+ tc->setIntReg(TheISA::SyscallPseudoReturnReg, 0);
+ ctc->setIntReg(TheISA::SyscallPseudoReturnReg, 1);
+ #endif
+
+ ctc->pcState(tc->nextInstAddr());
+
+ ctc->activate();
+
+ // Should return nonzero child TID in parent's syscall return register,
+ // but for our pthread library any non-zero value will work
+ return 1;
+ } else {
+ fatal("Called sys_clone, but no unallocated thread contexts found!\n");
+ return 0;
+ }
+}
+