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, 47 insertions, 0 deletions

diff --git a/src/arch/x86/process.hh b/src/arch/x86/process.hh
index 9e3fafbdd..4240ee625 100644
--- a/src/arch/x86/process.hh
+++ b/src/arch/x86/process.hh
@@ -82,6 +82,21 @@ namespace X86ISA
         SyscallDesc* getDesc(int callnum);
 
         void setSyscallReturn(ThreadContext *tc, SyscallReturn return_value);
+        void clone(ThreadContext *old_tc, ThreadContext *new_tc,
+                   Process *process, TheISA::IntReg flags);
+
+        X86Process &
+        operator=(const X86Process &in)
+        {
+            if (this == &in)
+                return *this;
+
+            _gdtStart = in._gdtStart;
+            _gdtSize = in._gdtSize;
+            syscallDescs = in.syscallDescs;
+
+            return *this;
+        }
     };
 
     class X86_64Process : public X86Process
@@ -97,6 +112,20 @@ namespace X86ISA
             Addr size;
             Addr vtimeOffset;
             Addr vgettimeofdayOffset;
+
+            VSyscallPage &
+            operator=(const VSyscallPage &in)
+            {
+                if (this == &in)
+                    return *this;
+
+                base = in.base;
+                size = in.size;
+                vtimeOffset = in.vtimeOffset;
+                vgettimeofdayOffset = in.vgettimeofdayOffset;
+
+                return *this;
+            }
         };
         VSyscallPage vsyscallPage;
 
@@ -108,6 +137,8 @@ namespace X86ISA
         /// Explicitly import the otherwise hidden getSyscallArg
         using Process::getSyscallArg;
         void setSyscallArg(ThreadContext *tc, int i, X86ISA::IntReg val);
+        void clone(ThreadContext *old_tc, ThreadContext *new_tc,
+                   Process *process, TheISA::IntReg flags);
     };
 
     class I386Process : public X86Process
@@ -123,6 +154,20 @@ namespace X86ISA
             Addr size;
             Addr vsyscallOffset;
             Addr vsysexitOffset;
+
+            VSyscallPage &
+            operator=(const VSyscallPage &in)
+            {
+                if (this == &in)
+                    return *this;
+
+                base = in.base;
+                size = in.size;
+                vsyscallOffset = in.vsyscallOffset;
+                vsysexitOffset = in.vsysexitOffset;
+
+                return *this;
+            }
         };
         VSyscallPage vsyscallPage;
 
@@ -134,6 +179,8 @@ namespace X86ISA
         X86ISA::IntReg getSyscallArg(ThreadContext *tc, int &i);
         X86ISA::IntReg getSyscallArg(ThreadContext *tc, int &i, int width);
         void setSyscallArg(ThreadContext *tc, int i, X86ISA::IntReg val);
+        void clone(ThreadContext *old_tc, ThreadContext *new_tc,
+                   Process *process, TheISA::IntReg flags);
     };
 
     /**