syscall_emul: [PATCH 15/22] add clone/execve for threading and multiprocess simulations

Modifies the clone system call and adds execve system call. Requires allowing
processes to steal thread contexts from other processes in the same system
object and the ability to detach pieces of process state (such as MemState)
to allow dynamic sharing.

1 files changed, 15 insertions, 13 deletions

diff --git a/src/arch/sparc/process.cc b/src/arch/sparc/process.cc
index a8359a9ce..a64bc587f 100644
--- a/src/arch/sparc/process.cc
+++ b/src/arch/sparc/process.cc
@@ -59,11 +59,12 @@ SparcProcess::SparcProcess(ProcessParams * params, ObjectFile *objFile,
 {
 
     // XXX all the below need to be updated for SPARC - Ali
-    brk_point = objFile->dataBase() + objFile->dataSize() + objFile->bssSize();
-    brk_point = roundUp(brk_point, PageBytes);
+    memState->brkPoint = objFile->dataBase() + objFile->dataSize() +
+                          objFile->bssSize();
+    memState->brkPoint = roundUp(memState->brkPoint, PageBytes);
 
     // Set pointer for next thread stack.  Reserve 8M for main stack.
-    next_thread_stack_base = stack_base - (8 * 1024 * 1024);
+    memState->nextThreadStackBase = memState->stackBase - (8 * 1024 * 1024);
 
     // Initialize these to 0s
     fillStart = 0;
@@ -324,15 +325,16 @@ SparcProcess::argsInit(int pageSize)
         aux_padding +
         frame_size;
 
-    stack_min = stack_base - space_needed;
-    stack_min = roundDown(stack_min, align);
-    stack_size = stack_base - stack_min;
+    memState->stackMin = memState->stackBase - space_needed;
+    memState->stackMin = roundDown(memState->stackMin, align);
+    memState->stackSize = memState->stackBase - memState->stackMin;
 
     // Allocate space for the stack
-    allocateMem(roundDown(stack_min, pageSize), roundUp(stack_size, pageSize));
+    allocateMem(roundDown(memState->stackMin, pageSize),
+                roundUp(memState->stackSize, pageSize));
 
     // map out initial stack contents
-    IntType sentry_base = stack_base - sentry_size;
+    IntType sentry_base = memState->stackBase - sentry_size;
     IntType file_name_base = sentry_base - file_name_size;
     IntType env_data_base = file_name_base - env_data_size;
     IntType arg_data_base = env_data_base - arg_data_size;
@@ -356,9 +358,9 @@ SparcProcess::argsInit(int pageSize)
     DPRINTF(Stack, "%#x - argv array\n", argv_array_base);
     DPRINTF(Stack, "%#x - argc \n", argc_base);
     DPRINTF(Stack, "%#x - window save\n", window_save_base);
-    DPRINTF(Stack, "%#x - stack min\n", stack_min);
+    DPRINTF(Stack, "%#x - stack min\n", memState->stackMin);
 
-    assert(window_save_base == stack_min);
+    assert(window_save_base == memState->stackMin);
 
     // write contents to stack
 
@@ -397,7 +399,7 @@ SparcProcess::argsInit(int pageSize)
     // Set up space for the trap handlers into the processes address space.
     // Since the stack grows down and there is reserved address space abov
     // it, we can put stuff above it and stay out of the way.
-    fillStart = stack_base;
+    fillStart = memState->stackBase;
     spillStart = fillStart + sizeof(MachInst) * numFillInsts;
 
     ThreadContext *tc = system->getThreadContext(contextIds[0]);
@@ -405,7 +407,7 @@ SparcProcess::argsInit(int pageSize)
     // assert(NumArgumentRegs >= 2);
     // tc->setIntReg(ArgumentReg[0], argc);
     // tc->setIntReg(ArgumentReg[1], argv_array_base);
-    tc->setIntReg(StackPointerReg, stack_min - StackBias);
+    tc->setIntReg(StackPointerReg, memState->stackMin - StackBias);
 
     // %g1 is a pointer to a function that should be run at exit. Since we
     // don't have anything like that, it should be set to 0.
@@ -414,7 +416,7 @@ SparcProcess::argsInit(int pageSize)
     tc->pcState(getStartPC());
 
     // Align the "stack_min" to a page boundary.
-    stack_min = roundDown(stack_min, pageSize);
+    memState->stackMin = roundDown(memState->stackMin, pageSize);
 }
 
 void