From 3f722b991fcb33ca21330501960406a8a58e2be2 Mon Sep 17 00:00:00 2001 From: Gabe Black Date: Fri, 30 Oct 2009 00:44:55 -0700 Subject: 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. --- src/arch/alpha/linux/process.cc | 15 ++++++++++----- src/arch/alpha/process.cc | 4 ++-- src/arch/alpha/process.hh | 2 +- src/arch/alpha/tru64/process.cc | 41 +++++++++++++++++++++++------------------ 4 files changed, 36 insertions(+), 26 deletions(-) (limited to 'src/arch/alpha') 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 name(process->getSyscallArg(tc, 0)); + int index = 0; + TypedBufferArg 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 fpcr(process->getSyscallArg(tc, 1)); + TypedBufferArg 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 fpcr(process->getSyscallArg(tc, 1)); + TypedBufferArg 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 name(process->getSyscallArg(tc, 0)); + int index = 0; + TypedBufferArg 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 max_cpu(process->getSyscallArg(tc, 1)); + TypedBufferArg max_cpu(bufPtr); *max_cpu = htog((uint32_t)process->numCpus()); max_cpu.copyOut(tc->getMemPort()); return 1; } case AlphaTru64::GSI_CPUS_IN_BOX: { - TypedBufferArg cpus_in_box(process->getSyscallArg(tc, 1)); + TypedBufferArg 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 physmem(process->getSyscallArg(tc, 1)); + TypedBufferArg physmem(bufPtr); *physmem = htog((uint64_t)1024 * 1024); // physical memory in KB physmem.copyOut(tc->getMemPort()); return 1; } case AlphaTru64::GSI_CPU_INFO: { - TypedBufferArg - infop(process->getSyscallArg(tc, 1)); + TypedBufferArg 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 proc_type(process->getSyscallArg(tc, 1)); + TypedBufferArg 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 clk_hz(process->getSyscallArg(tc, 1)); + TypedBufferArg 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 elp(process->getSyscallArg(tc, 2)); + TypedBufferArg elp(bufPtr); const int clk_hz = one_million; elp->si_user = htog(curTick / (Clock::Frequency / clk_hz)); -- cgit v1.2.3