Commit m5threads package.
This patch adds limited multithreading support in syscall-emulation
mode, by using the clone system call. The clone system call works
for Alpha, SPARC and x86, and multithreaded applications run
correctly in Alpha and SPARC.
diff --git a/src/sim/syscall_emul.cc b/src/sim/syscall_emul.cc
index f0a693d..d3161de 100644
--- a/src/sim/syscall_emul.cc
+++ b/src/sim/syscall_emul.cc
@@ -106,6 +106,19 @@
SyscallReturn
+exitGroupFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
+ ThreadContext *tc)
+{
+ // really should just halt all thread contexts belonging to this
+ // process in case there's another process running...
+ exitSimLoop("target called exit()",
+ process->getSyscallArg(tc, 0) & 0xff);
+
+ return 1;
+}
+
+
+SyscallReturn
getpagesizeFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc)
{
return (int)VMPageSize;
@@ -641,3 +654,81 @@
}
+SyscallReturn
+cloneFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
+ ThreadContext *tc)
+{
+ DPRINTF(SyscallVerbose, "In sys_clone:\n");
+ DPRINTF(SyscallVerbose, " Flags=%llx\n", tc->getSyscallArg(0));
+ DPRINTF(SyscallVerbose, " Child stack=%llx\n", tc->getSyscallArg(1));
+
+
+ if (tc->getSyscallArg(0) != 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", tc->getSyscallArg(0));
+ }
+
+ 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->setMiscRegNoEffect(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));
+ #else
+ fatal("sys_clone is not implemented for this ISA\n");
+ #endif
+
+ //Set up stack register
+ ctc->setIntReg(TheISA::StackPointerReg, tc->getSyscallArg(1));
+
+ //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(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->setPC(tc->readNextPC());
+ ctc->setNextPC(tc->readNextPC() + sizeof(TheISA::MachInst));
+
+ //In SPARC, need NNPC too...
+ #if THE_ISA == SPARC_ISA
+ ctc->setNextNPC(tc->readNextNPC() + sizeof(TheISA::MachInst));
+ #endif
+
+ 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;
+ }
+}
+
