Syscalls: Make system calls access arguments like a stack, not an array.

When accessing arguments for a syscall, the position of an argument depends on
the policies of the ISA, how much space preceding arguments took up, and the
"alignment" of the index for this particular argument into the number of
possible storate locations. This change adjusts getSyscallArg to take its
index parameter by reference instead of value and to adjust it to point to the
possible location of the next argument on the stack, basically just after the
current one. This way, the rules for the new argument can be applied locally
without knowing about other arguments since those have already been taken into
account implicitly.

All system calls have also been changed to reflect the new interface. In a
number of cases this made the implementation clearer since it encourages
arguments to be collected in one place in order and then used as necessary
later, as opposed to scattering them throughout the function or using them in
place in long expressions. It also discourages using getSyscallArg over and
over to retrieve the same value when a temporary would do the job.

22 files changed, 108 insertions, 72 deletions

diff --git a/src/arch/alpha/linux/process.cc b/src/arch/alpha/linux/process.cc
index 0f09e472b..a653d7845 100644
--- a/src/arch/alpha/linux/process.cc
+++ b/src/arch/alpha/linux/process.cc
@@ -48,7 +48,8 @@ static SyscallReturn
 unameFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
           ThreadContext *tc)
 {
-    TypedBufferArg<Linux::utsname> name(process->getSyscallArg(tc, 0));
+    int index = 0;
+    TypedBufferArg<Linux::utsname> name(process->getSyscallArg(tc, index));
 
     strcpy(name->sysname, "Linux");
     strcpy(name->nodename, "m5.eecs.umich.edu");
@@ -67,13 +68,15 @@ static SyscallReturn
 osf_getsysinfoFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
                    ThreadContext *tc)
 {
-    unsigned op = process->getSyscallArg(tc, 0);
+    int index = 0;
+    unsigned op = process->getSyscallArg(tc, index);
+    Addr bufPtr = process->getSyscallArg(tc, index);
     // unsigned nbytes = process->getSyscallArg(tc, 2);
 
     switch (op) {
 
       case 45: { // GSI_IEEE_FP_CONTROL
-          TypedBufferArg<uint64_t> fpcr(process->getSyscallArg(tc, 1));
+          TypedBufferArg<uint64_t> fpcr(bufPtr);
           // I don't think this exactly matches the HW FPCR
           *fpcr = 0;
           fpcr.copyOut(tc->getMemPort());
@@ -94,13 +97,15 @@ static SyscallReturn
 osf_setsysinfoFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
                    ThreadContext *tc)
 {
-    unsigned op = process->getSyscallArg(tc, 0);
+    int index = 0;
+    unsigned op = process->getSyscallArg(tc, index);
+    Addr bufPtr = process->getSyscallArg(tc, index);
     // unsigned nbytes = process->getSyscallArg(tc, 2);
 
     switch (op) {
 
       case 14: { // SSI_IEEE_FP_CONTROL
-          TypedBufferArg<uint64_t> fpcr(process->getSyscallArg(tc, 1));
+          TypedBufferArg<uint64_t> fpcr(bufPtr);
           // I don't think this exactly matches the HW FPCR
           fpcr.copyIn(tc->getMemPort());
           DPRINTFR(SyscallVerbose, "osf_setsysinfo(SSI_IEEE_FP_CONTROL): "
diff --git a/src/arch/alpha/process.cc b/src/arch/alpha/process.cc
index 6aad45da8..9d75d5fa1 100644
--- a/src/arch/alpha/process.cc
+++ b/src/arch/alpha/process.cc
@@ -193,10 +193,10 @@ AlphaLiveProcess::startup()
 }
 
 AlphaISA::IntReg
-AlphaLiveProcess::getSyscallArg(ThreadContext *tc, int i)
+AlphaLiveProcess::getSyscallArg(ThreadContext *tc, int &i)
 {
     assert(i < 6);
-    return tc->readIntReg(FirstArgumentReg + i);
+    return tc->readIntReg(FirstArgumentReg + i++);
 }
 
 void
diff --git a/src/arch/alpha/process.hh b/src/arch/alpha/process.hh
index 6d083c5ac..36b25a48e 100644
--- a/src/arch/alpha/process.hh
+++ b/src/arch/alpha/process.hh
@@ -44,7 +44,7 @@ class AlphaLiveProcess : public LiveProcess
     void argsInit(int intSize, int pageSize);
 
   public:
-    AlphaISA::IntReg getSyscallArg(ThreadContext *tc, int i);
+    AlphaISA::IntReg getSyscallArg(ThreadContext *tc, int &i);
     void setSyscallArg(ThreadContext *tc, int i, AlphaISA::IntReg val);
     void setSyscallReturn(ThreadContext *tc, SyscallReturn return_value);
 };
diff --git a/src/arch/alpha/tru64/process.cc b/src/arch/alpha/tru64/process.cc
index 8fa3cdeda..b039fbe19 100644
--- a/src/arch/alpha/tru64/process.cc
+++ b/src/arch/alpha/tru64/process.cc
@@ -45,7 +45,8 @@ static SyscallReturn
 unameFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
           ThreadContext *tc)
 {
-    TypedBufferArg<AlphaTru64::utsname> name(process->getSyscallArg(tc, 0));
+    int index = 0;
+    TypedBufferArg<AlphaTru64::utsname> name(process->getSyscallArg(tc, index));
 
     strcpy(name->sysname, "OSF1");
     strcpy(name->nodename, "m5.eecs.umich.edu");
@@ -62,35 +63,36 @@ static SyscallReturn
 getsysinfoFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
                ThreadContext *tc)
 {
-    unsigned op = process->getSyscallArg(tc, 0);
-    unsigned nbytes = process->getSyscallArg(tc, 2);
+    int index = 0;
+    unsigned op = process->getSyscallArg(tc, index);
+    Addr bufPtr = process->getSyscallArg(tc, index);
+    unsigned nbytes = process->getSyscallArg(tc, index);
 
     switch (op) {
 
       case AlphaTru64::GSI_MAX_CPU: {
-          TypedBufferArg<uint32_t> max_cpu(process->getSyscallArg(tc, 1));
+          TypedBufferArg<uint32_t> max_cpu(bufPtr);
           *max_cpu = htog((uint32_t)process->numCpus());
           max_cpu.copyOut(tc->getMemPort());
           return 1;
       }
 
       case AlphaTru64::GSI_CPUS_IN_BOX: {
-          TypedBufferArg<uint32_t> cpus_in_box(process->getSyscallArg(tc, 1));
+          TypedBufferArg<uint32_t> cpus_in_box(bufPtr);
           *cpus_in_box = htog((uint32_t)process->numCpus());
           cpus_in_box.copyOut(tc->getMemPort());
           return 1;
       }
 
       case AlphaTru64::GSI_PHYSMEM: {
-          TypedBufferArg<uint64_t> physmem(process->getSyscallArg(tc, 1));
+          TypedBufferArg<uint64_t> physmem(bufPtr);
           *physmem = htog((uint64_t)1024 * 1024);  // physical memory in KB
           physmem.copyOut(tc->getMemPort());
           return 1;
       }
 
       case AlphaTru64::GSI_CPU_INFO: {
-          TypedBufferArg<AlphaTru64::cpu_info>
-              infop(process->getSyscallArg(tc, 1));
+          TypedBufferArg<AlphaTru64::cpu_info> infop(bufPtr);
 
           infop->current_cpu = htog(0);
           infop->cpus_in_box = htog(process->numCpus());
@@ -107,14 +109,14 @@ getsysinfoFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
       }
 
       case AlphaTru64::GSI_PROC_TYPE: {
-          TypedBufferArg<uint64_t> proc_type(process->getSyscallArg(tc, 1));
+          TypedBufferArg<uint64_t> proc_type(bufPtr);
           *proc_type = htog((uint64_t)11);
           proc_type.copyOut(tc->getMemPort());
           return 1;
       }
 
       case AlphaTru64::GSI_PLATFORM_NAME: {
-          BufferArg bufArg(process->getSyscallArg(tc, 1), nbytes);
+          BufferArg bufArg(bufPtr, nbytes);
           strncpy((char *)bufArg.bufferPtr(),
                   "COMPAQ Professional Workstation XP1000",
                   nbytes);
@@ -123,7 +125,7 @@ getsysinfoFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
       }
 
       case AlphaTru64::GSI_CLK_TCK: {
-          TypedBufferArg<uint64_t> clk_hz(process->getSyscallArg(tc, 1));
+          TypedBufferArg<uint64_t> clk_hz(bufPtr);
           *clk_hz = htog((uint64_t)1024);
           clk_hz.copyOut(tc->getMemPort());
           return 1;
@@ -142,12 +144,13 @@ static SyscallReturn
 setsysinfoFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
                ThreadContext *tc)
 {
-    unsigned op = process->getSyscallArg(tc, 0);
+    int index = 0;
+    unsigned op = process->getSyscallArg(tc, index);
 
     switch (op) {
       case AlphaTru64::SSI_IEEE_FP_CONTROL:
         warn("setsysinfo: ignoring ieee_set_fp_control() arg 0x%x\n",
-             process->getSyscallArg(tc, 1));
+             process->getSyscallArg(tc, index));
         break;
 
       default:
@@ -165,17 +168,19 @@ tableFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
 {
     using namespace std;
 
-    int id = process->getSyscallArg(tc, 0);      // table ID
-    int index = process->getSyscallArg(tc, 1);   // index into table
+    int argIndex = 0;
+    int id = process->getSyscallArg(tc, argIndex);    // table ID
+    int index = process->getSyscallArg(tc, argIndex); // index into table
+    Addr bufPtr = process->getSyscallArg(tc, argIndex);
     // arg 2 is buffer pointer; type depends on table ID
-    int nel = process->getSyscallArg(tc, 3);     // number of elements
-    int lel = process->getSyscallArg(tc, 4);     // expected element size
+    int nel = process->getSyscallArg(tc, argIndex);   // number of elements
+    int lel = process->getSyscallArg(tc, argIndex);   // expected element size
 
     switch (id) {
       case AlphaTru64::TBL_SYSINFO: {
           if (index != 0 || nel != 1 || lel != sizeof(Tru64::tbl_sysinfo))
               return -EINVAL;
-          TypedBufferArg<Tru64::tbl_sysinfo> elp(process->getSyscallArg(tc, 2));
+          TypedBufferArg<Tru64::tbl_sysinfo> elp(bufPtr);
 
           const int clk_hz = one_million;
           elp->si_user = htog(curTick / (Clock::Frequency / clk_hz));
diff --git a/src/arch/arm/linux/process.cc b/src/arch/arm/linux/process.cc
index a7f36e18d..f909d871a 100644
--- a/src/arch/arm/linux/process.cc
+++ b/src/arch/arm/linux/process.cc
@@ -50,7 +50,8 @@ static SyscallReturn
 unameFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
           ThreadContext *tc)
 {
-    TypedBufferArg<Linux::utsname> name(process->getSyscallArg(tc, 0));
+    int index = 0;
+    TypedBufferArg<Linux::utsname> name(process->getSyscallArg(tc, index));
 
     strcpy(name->sysname, "Linux");
     strcpy(name->nodename, "m5.eecs.umich.edu");
@@ -417,7 +418,8 @@ static SyscallReturn
 setTLSFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
           ThreadContext *tc)
 {
-    uint32_t tlsPtr = process->getSyscallArg(tc, 0);
+    int index = 0;
+    uint32_t tlsPtr = process->getSyscallArg(tc, index);
 
     tc->getMemPort()->writeBlob(ArmLinuxProcess::commPage + 0x0ff0,
                                 (uint8_t *)&tlsPtr, sizeof(tlsPtr));
@@ -511,12 +513,12 @@ ArmLinuxProcess::startup()
 }
 
 ArmISA::IntReg
-ArmLinuxProcess::getSyscallArg(ThreadContext *tc, int i)
+ArmLinuxProcess::getSyscallArg(ThreadContext *tc, int &i)
 {
     // Linux apparently allows more parameter than the ABI says it should.
     // This limit may need to be increased even further.
     assert(i < 6);
-    return tc->readIntReg(ArgumentReg0 + i);
+    return tc->readIntReg(ArgumentReg0 + i++);
 }
 
 void
diff --git a/src/arch/arm/linux/process.hh b/src/arch/arm/linux/process.hh
index 53b3781d2..ab836fab2 100644
--- a/src/arch/arm/linux/process.hh
+++ b/src/arch/arm/linux/process.hh
@@ -44,7 +44,7 @@ class ArmLinuxProcess : public ArmLiveProcess
 
     void startup();
 
-    ArmISA::IntReg getSyscallArg(ThreadContext *tc, int i);
+    ArmISA::IntReg getSyscallArg(ThreadContext *tc, int &i);
     void setSyscallArg(ThreadContext *tc, int i, ArmISA::IntReg val);
 
     /// The target system's hostname.
diff --git a/src/arch/arm/process.cc b/src/arch/arm/process.cc
index cd7cc9736..702922a43 100644
--- a/src/arch/arm/process.cc
+++ b/src/arch/arm/process.cc
@@ -324,10 +324,10 @@ ArmLiveProcess::argsInit(int intSize, int pageSize)
 }
 
 ArmISA::IntReg
-ArmLiveProcess::getSyscallArg(ThreadContext *tc, int i)
+ArmLiveProcess::getSyscallArg(ThreadContext *tc, int &i)
 {
     assert(i < 4);
-    return tc->readIntReg(ArgumentReg0 + i);
+    return tc->readIntReg(ArgumentReg0 + i++);
 }
 
 void
diff --git a/src/arch/arm/process.hh b/src/arch/arm/process.hh
index 8954d3719..f793892d0 100644
--- a/src/arch/arm/process.hh
+++ b/src/arch/arm/process.hh
@@ -53,7 +53,7 @@ class ArmLiveProcess : public LiveProcess
   public:
     void argsInit(int intSize, int pageSize);
 
-    ArmISA::IntReg getSyscallArg(ThreadContext *tc, int i);
+    ArmISA::IntReg getSyscallArg(ThreadContext *tc, int &i);
     void setSyscallArg(ThreadContext *tc, int i, ArmISA::IntReg val);
     void setSyscallReturn(ThreadContext *tc, SyscallReturn return_value);
 };
diff --git a/src/arch/mips/linux/process.cc b/src/arch/mips/linux/process.cc
index dde3a4efd..c2a05b73b 100644
--- a/src/arch/mips/linux/process.cc
+++ b/src/arch/mips/linux/process.cc
@@ -51,7 +51,8 @@ static SyscallReturn
 unameFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
           ThreadContext *tc)
 {
-    TypedBufferArg<Linux::utsname> name(process->getSyscallArg(tc, 0));
+    int index = 0;
+    TypedBufferArg<Linux::utsname> name(process->getSyscallArg(tc, index));
 
     strcpy(name->sysname, "Linux");
     strcpy(name->nodename,"m5.eecs.umich.edu");
@@ -70,14 +71,16 @@ static SyscallReturn
 sys_getsysinfoFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
                    ThreadContext *tc)
 {
-    unsigned op = process->getSyscallArg(tc, 0);
-    // unsigned nbytes = process->getSyscallArg(tc, 2);
+    int index = 0;
+    unsigned op = process->getSyscallArg(tc, index);
+    unsigned bufPtr = process->getSyscallArg(tc, index);
+    // unsigned nbytes = process->getSyscallArg(tc, index);
 
     switch (op) {
       case 45:
         { 
             // GSI_IEEE_FP_CONTROL
-            TypedBufferArg<uint64_t> fpcr(process->getSyscallArg(tc, 1));
+            TypedBufferArg<uint64_t> fpcr(bufPtr);
             // I don't think this exactly matches the HW FPCR
             *fpcr = 0;
             fpcr.copyOut(tc->getMemPort());
@@ -97,15 +100,17 @@ static SyscallReturn
 sys_setsysinfoFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
                    ThreadContext *tc)
 {
-    unsigned op = process->getSyscallArg(tc, 0);
-    // unsigned nbytes = process->getSyscallArg(tc, 2);
+    int index = 0;
+    unsigned op = process->getSyscallArg(tc, index);
+    Addr bufPtr = process->getSyscallArg(tc, index);
+    // unsigned nbytes = process->getSyscallArg(tc, index);
 
     switch (op) {
 
       case 14:
         {
             // SSI_IEEE_FP_CONTROL
-            TypedBufferArg<uint64_t> fpcr(process->getSyscallArg(tc, 1));
+            TypedBufferArg<uint64_t> fpcr(bufPtr);
             // I don't think this exactly matches the HW FPCR
             fpcr.copyIn(tc->getMemPort());
             DPRINTFR(SyscallVerbose, "sys_setsysinfo(SSI_IEEE_FP_CONTROL): "
diff --git a/src/arch/mips/process.cc b/src/arch/mips/process.cc
index b9f608922..d96b0c81c 100644
--- a/src/arch/mips/process.cc
+++ b/src/arch/mips/process.cc
@@ -147,10 +147,10 @@ MipsLiveProcess::argsInit(int intSize, int pageSize)
 
 
 MipsISA::IntReg
-MipsLiveProcess::getSyscallArg(ThreadContext *tc, int i)
+MipsLiveProcess::getSyscallArg(ThreadContext *tc, int &i)
 {
     assert(i < 6);
-    return tc->readIntReg(FirstArgumentReg + i);
+    return tc->readIntReg(FirstArgumentReg + i++);
 }
 
 void
diff --git a/src/arch/mips/process.hh b/src/arch/mips/process.hh
index b8f4de20a..f35ec8554 100644
--- a/src/arch/mips/process.hh
+++ b/src/arch/mips/process.hh
@@ -50,7 +50,7 @@ class MipsLiveProcess : public LiveProcess
     void argsInit(int intSize, int pageSize);
 
   public:
-    MipsISA::IntReg getSyscallArg(ThreadContext *tc, int i);
+    MipsISA::IntReg getSyscallArg(ThreadContext *tc, int &i);
     void setSyscallArg(ThreadContext *tc, int i, MipsISA::IntReg val);
     void setSyscallReturn(ThreadContext *tc, SyscallReturn return_value);
 };
diff --git a/src/arch/power/linux/process.cc b/src/arch/power/linux/process.cc
index b03ccfc8c..504d0e334 100644
--- a/src/arch/power/linux/process.cc
+++ b/src/arch/power/linux/process.cc
@@ -52,7 +52,8 @@ static SyscallReturn
 unameFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
           ThreadContext *tc)
 {
-    TypedBufferArg<Linux::utsname> name(process->getSyscallArg(tc, 0));
+    int index = 0;
+    TypedBufferArg<Linux::utsname> name(process->getSyscallArg(tc, index));
 
     strcpy(name->sysname, "Linux");
     strcpy(name->nodename, "m5.eecs.umich.edu");
@@ -437,12 +438,12 @@ PowerLinuxProcess::startup()
 }
 
 PowerISA::IntReg
-PowerLinuxProcess::getSyscallArg(ThreadContext *tc, int i)
+PowerLinuxProcess::getSyscallArg(ThreadContext *tc, int &i)
 {
     // Linux apparently allows more parameter than the ABI says it should.
     // This limit may need to be increased even further.
     assert(i < 6);
-    return tc->readIntReg(ArgumentReg0 + i);
+    return tc->readIntReg(ArgumentReg0 + i++);
 }
 
 void
diff --git a/src/arch/power/linux/process.hh b/src/arch/power/linux/process.hh
index 78b0eef7f..db6759a77 100644
--- a/src/arch/power/linux/process.hh
+++ b/src/arch/power/linux/process.hh
@@ -46,7 +46,7 @@ class PowerLinuxProcess : public PowerLiveProcess
 
     void startup();
 
-    PowerISA::IntReg getSyscallArg(ThreadContext *tc, int i);
+    PowerISA::IntReg getSyscallArg(ThreadContext *tc, int &i);
     void setSyscallArg(ThreadContext *tc, int i, PowerISA::IntReg val);
 
     /// Array of syscall descriptors, indexed by call number.
diff --git a/src/arch/power/process.cc b/src/arch/power/process.cc
index 8828a1a93..92f993e4c 100644
--- a/src/arch/power/process.cc
+++ b/src/arch/power/process.cc
@@ -266,10 +266,10 @@ PowerLiveProcess::argsInit(int intSize, int pageSize)
 }
 
 PowerISA::IntReg
-PowerLiveProcess::getSyscallArg(ThreadContext *tc, int i)
+PowerLiveProcess::getSyscallArg(ThreadContext *tc, int &i)
 {
     assert(i < 5);
-    return tc->readIntReg(ArgumentReg0 + i);
+    return tc->readIntReg(ArgumentReg0 + i++);
 }
 
 void
diff --git a/src/arch/power/process.hh b/src/arch/power/process.hh
index dae776c4c..ede75f05f 100644
--- a/src/arch/power/process.hh
+++ b/src/arch/power/process.hh
@@ -50,7 +50,7 @@ class PowerLiveProcess : public LiveProcess
 
   public:
     void argsInit(int intSize, int pageSize);
-    PowerISA::IntReg getSyscallArg(ThreadContext *tc, int i);
+    PowerISA::IntReg getSyscallArg(ThreadContext *tc, int &i);
     void setSyscallArg(ThreadContext *tc, int i, PowerISA::IntReg val);
     void setSyscallReturn(ThreadContext *tc, SyscallReturn return_value);
 };
diff --git a/src/arch/sparc/linux/syscalls.cc b/src/arch/sparc/linux/syscalls.cc
index c50803976..874ddc005 100644
--- a/src/arch/sparc/linux/syscalls.cc
+++ b/src/arch/sparc/linux/syscalls.cc
@@ -41,7 +41,8 @@ static SyscallReturn
 unameFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
         ThreadContext *tc)
 {
-    TypedBufferArg<Linux::utsname> name(process->getSyscallArg(tc, 0));
+    int index = 0;
+    TypedBufferArg<Linux::utsname> name(process->getSyscallArg(tc, index));
 
     strcpy(name->sysname, "Linux");
     strcpy(name->nodename, "m5.eecs.umich.edu");
@@ -59,9 +60,10 @@ SyscallReturn getresuidFunc(SyscallDesc *desc, int num,
         LiveProcess *p, ThreadContext *tc)
 {
     const IntReg id = htog(100);
-    Addr ruid = p->getSyscallArg(tc, 0);
-    Addr euid = p->getSyscallArg(tc, 1);
-    Addr suid = p->getSyscallArg(tc, 2);
+    int index = 0;
+    Addr ruid = p->getSyscallArg(tc, index);
+    Addr euid = p->getSyscallArg(tc, index);
+    Addr suid = p->getSyscallArg(tc, index);
     //Handle the EFAULT case
     //Set the ruid
     if(ruid)
diff --git a/src/arch/sparc/process.cc b/src/arch/sparc/process.cc
index 89e853573..7e01f6b07 100644
--- a/src/arch/sparc/process.cc
+++ b/src/arch/sparc/process.cc
@@ -514,10 +514,10 @@ void Sparc64LiveProcess::flushWindows(ThreadContext *tc)
 }
 
 IntReg
-Sparc32LiveProcess::getSyscallArg(ThreadContext *tc, int i)
+Sparc32LiveProcess::getSyscallArg(ThreadContext *tc, int &i)
 {
     assert(i < 6);
-    return bits(tc->readIntReg(FirstArgumentReg + i), 31, 0);
+    return bits(tc->readIntReg(FirstArgumentReg + i++), 31, 0);
 }
 
 void
@@ -528,10 +528,10 @@ Sparc32LiveProcess::setSyscallArg(ThreadContext *tc, int i, IntReg val)
 }
 
 IntReg
-Sparc64LiveProcess::getSyscallArg(ThreadContext *tc, int i)
+Sparc64LiveProcess::getSyscallArg(ThreadContext *tc, int &i)
 {
     assert(i < 6);
-    return tc->readIntReg(FirstArgumentReg + i);
+    return tc->readIntReg(FirstArgumentReg + i++);
 }
 
 void
diff --git a/src/arch/sparc/process.hh b/src/arch/sparc/process.hh
index fdb9734ba..cca312e0a 100644
--- a/src/arch/sparc/process.hh
+++ b/src/arch/sparc/process.hh
@@ -95,7 +95,7 @@ class Sparc32LiveProcess : public SparcLiveProcess
 
     void flushWindows(ThreadContext *tc);
 
-    SparcISA::IntReg getSyscallArg(ThreadContext *tc, int i);
+    SparcISA::IntReg getSyscallArg(ThreadContext *tc, int &i);
     void setSyscallArg(ThreadContext *tc, int i, SparcISA::IntReg val);
 };
 
@@ -123,7 +123,7 @@ class Sparc64LiveProcess : public SparcLiveProcess
 
     void flushWindows(ThreadContext *tc);
 
-    SparcISA::IntReg getSyscallArg(ThreadContext *tc, int i);
+    SparcISA::IntReg getSyscallArg(ThreadContext *tc, int &i);
     void setSyscallArg(ThreadContext *tc, int i, SparcISA::IntReg val);
 };
 
diff --git a/src/arch/sparc/solaris/process.cc b/src/arch/sparc/solaris/process.cc
index eafb488df..24abd8687 100644
--- a/src/arch/sparc/solaris/process.cc
+++ b/src/arch/sparc/solaris/process.cc
@@ -48,7 +48,8 @@ static SyscallReturn
 unameFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
           ThreadContext *tc)
 {
-    TypedBufferArg<Solaris::utsname> name(process->getSyscallArg(tc, 0));
+    int index = 0;
+    TypedBufferArg<Solaris::utsname> name(process->getSyscallArg(tc, index));
 
     strcpy(name->sysname, "SunOS");
     strcpy(name->nodename, "m5.eecs.umich.edu");
diff --git a/src/arch/x86/linux/syscalls.cc b/src/arch/x86/linux/syscalls.cc
index 14b3fa69b..4c29559fb 100644
--- a/src/arch/x86/linux/syscalls.cc
+++ b/src/arch/x86/linux/syscalls.cc
@@ -68,7 +68,8 @@ static SyscallReturn
 unameFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
           ThreadContext *tc)
 {
-    TypedBufferArg<Linux::utsname> name(process->getSyscallArg(tc, 0));
+    int index = 0;
+    TypedBufferArg<Linux::utsname> name(process->getSyscallArg(tc, index));
 
     strcpy(name->sysname, "Linux");
     strcpy(name->nodename, "m5.eecs.umich.edu");
@@ -94,8 +95,9 @@ archPrctlFunc(SyscallDesc *desc, int callnum, LiveProcess *process,
     };
 
     //First argument is the code, second is the address
-    int code = process->getSyscallArg(tc, 0);
-    uint64_t addr = process->getSyscallArg(tc, 1);
+    int index = 0;
+    int code = process->getSyscallArg(tc, index);
+    uint64_t addr = process->getSyscallArg(tc, index);
     uint64_t fsBase, gsBase;
     TranslatingPort *p = tc->getMemPort();
     switch(code)
@@ -159,7 +161,8 @@ setThreadArea32Func(SyscallDesc *desc, int callnum,
 
     assert((maxTLSEntry + 1) * sizeof(uint64_t) <= x86lp->gdtSize());
 
-    TypedBufferArg<UserDesc32> userDesc(process->getSyscallArg(tc, 0));
+    int argIndex = 0;
+    TypedBufferArg<UserDesc32> userDesc(process->getSyscallArg(tc, argIndex));
     TypedBufferArg<uint64_t>
         gdt(x86lp->gdtStart() + minTLSEntry * sizeof(uint64_t),
                 numTLSEntries * sizeof(uint64_t));
diff --git a/src/arch/x86/process.cc b/src/arch/x86/process.cc
index f7678443d..f7b3ce24a 100644
--- a/src/arch/x86/process.cc
+++ b/src/arch/x86/process.cc
@@ -698,10 +698,10 @@ X86LiveProcess::setSyscallReturn(ThreadContext *tc, SyscallReturn return_value)
 }
 
 X86ISA::IntReg
-X86_64LiveProcess::getSyscallArg(ThreadContext *tc, int i)
+X86_64LiveProcess::getSyscallArg(ThreadContext *tc, int &i)
 {
     assert(i < NumArgumentRegs);
-    return tc->readIntReg(ArgumentReg[i]);
+    return tc->readIntReg(ArgumentReg[i++]);
 }
 
 void
@@ -712,10 +712,21 @@ X86_64LiveProcess::setSyscallArg(ThreadContext *tc, int i, X86ISA::IntReg val)
 }
 
 X86ISA::IntReg
-I386LiveProcess::getSyscallArg(ThreadContext *tc, int i)
+I386LiveProcess::getSyscallArg(ThreadContext *tc, int &i)
 {
     assert(i < NumArgumentRegs32);
-    return tc->readIntReg(ArgumentReg32[i]);
+    return tc->readIntReg(ArgumentReg32[i++]);
+}
+
+X86ISA::IntReg
+I386LiveProcess::getSyscallArg(ThreadContext *tc, int &i, int width)
+{
+    assert(width == 32 || width == 64);
+    assert(i < NumArgumentRegs);
+    uint64_t retVal = tc->readIntReg(ArgumentReg32[i++]) & mask(32);
+    if (width == 64)
+        retVal |= ((uint64_t)tc->readIntReg(ArgumentReg[i++]) << 32);
+    return retVal;
 }
 
 void
diff --git a/src/arch/x86/process.hh b/src/arch/x86/process.hh
index cd6d99e66..4d031bd5a 100644
--- a/src/arch/x86/process.hh
+++ b/src/arch/x86/process.hh
@@ -105,7 +105,7 @@ namespace X86ISA
         void argsInit(int intSize, int pageSize);
         void startup();
 
-        X86ISA::IntReg getSyscallArg(ThreadContext *tc, int i);
+        X86ISA::IntReg getSyscallArg(ThreadContext *tc, int &i);
         void setSyscallArg(ThreadContext *tc, int i, X86ISA::IntReg val);
     };
 
@@ -130,7 +130,8 @@ namespace X86ISA
         void startup();
 
         void syscall(int64_t callnum, ThreadContext *tc);
-        X86ISA::IntReg getSyscallArg(ThreadContext *tc, int i);
+        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);
     };
 }