gem5/src/arch/sparc/stacktrace.cc

/*
 * Copyright (c) 2005 The Regents of The University of Michigan
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met: redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer;
 * redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution;
 * neither the name of the copyright holders nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Authors: Nathan Binkert
 */

#include <string>

#include "arch/sparc/isa_traits.hh"
#include "arch/sparc/stacktrace.hh"
#include "arch/sparc/vtophys.hh"
#include "base/bitfield.hh"
#include "base/trace.hh"
#include "cpu/base.hh"
#include "cpu/thread_context.hh"
#include "sim/system.hh"

using namespace std;
namespace SparcISA
{
    ProcessInfo::ProcessInfo(ThreadContext *_tc)
        : tc(_tc)
    {
        Addr addr = 0;

        VirtualPort *vp;

        vp = tc->getVirtPort();

        if (!tc->getSystemPtr()->kernelSymtab->findAddress("thread_info_size", addr))
            panic("thread info not compiled into kernel\n");
        thread_info_size = vp->readGtoH<int32_t>(addr);

        if (!tc->getSystemPtr()->kernelSymtab->findAddress("task_struct_size", addr))
            panic("thread info not compiled into kernel\n");
        task_struct_size = vp->readGtoH<int32_t>(addr);

        if (!tc->getSystemPtr()->kernelSymtab->findAddress("thread_info_task", addr))
            panic("thread info not compiled into kernel\n");
        task_off = vp->readGtoH<int32_t>(addr);

        if (!tc->getSystemPtr()->kernelSymtab->findAddress("task_struct_pid", addr))
            panic("thread info not compiled into kernel\n");
        pid_off = vp->readGtoH<int32_t>(addr);

        if (!tc->getSystemPtr()->kernelSymtab->findAddress("task_struct_comm", addr))
            panic("thread info not compiled into kernel\n");
        name_off = vp->readGtoH<int32_t>(addr);

        tc->delVirtPort(vp);
    }

    Addr
    ProcessInfo::task(Addr ksp) const
    {
        Addr base = ksp & ~0x3fff;
        if (base == ULL(0xfffffc0000000000))
            return 0;

        Addr tsk;

        VirtualPort *vp;

        vp = tc->getVirtPort();
        tsk = vp->readGtoH<Addr>(base + task_off);
        tc->delVirtPort(vp);

        return tsk;
    }

    int
    ProcessInfo::pid(Addr ksp) const
    {
        Addr task = this->task(ksp);
        if (!task)
            return -1;

        uint16_t pd;

        VirtualPort *vp;

        vp = tc->getVirtPort();
        pd = vp->readGtoH<uint16_t>(task + pid_off);
        tc->delVirtPort(vp);

        return pd;
    }

    string
    ProcessInfo::name(Addr ksp) const
    {
        Addr task = this->task(ksp);
        if (!task)
            return "console";

        char comm[256];
        CopyStringOut(tc, comm, task + name_off, sizeof(comm));
        if (!comm[0])
            return "startup";

        return comm;
    }

    StackTrace::StackTrace()
        : tc(0), stack(64)
    {
    }

    StackTrace::StackTrace(ThreadContext *_tc, StaticInstPtr inst)
        : tc(0), stack(64)
    {
        trace(_tc, inst);
    }

    StackTrace::~StackTrace()
    {
    }

    void
    StackTrace::trace(ThreadContext *_tc, bool is_call)
    {
#if 0
        tc = _tc;

        bool usermode = (tc->readMiscReg(AlphaISA::IPR_DTB_CM) & 0x18) != 0;

        Addr pc = tc->readNextPC();
        bool kernel = tc->getSystemPtr()->kernelStart <= pc &&
            pc <= tc->getSystemPtr()->kernelEnd;

        if (usermode) {
            stack.push_back(user);
            return;
        }

        if (!kernel) {
            stack.push_back(console);
            return;
        }

        SymbolTable *symtab = tc->getSystemPtr()->kernelSymtab;
        Addr ksp = tc->readIntReg(TheISA::StackPointerReg);
        Addr bottom = ksp & ~0x3fff;
        Addr addr;

        if (is_call) {
            if (!symtab->findNearestAddr(pc, addr))
                panic("could not find address %#x", pc);

            stack.push_back(addr);
            pc = tc->readPC();
        }

        Addr ra;
        int size;

        while (ksp > bottom) {
            if (!symtab->findNearestAddr(pc, addr))
                panic("could not find symbol for pc=%#x", pc);
            assert(pc >= addr && "symbol botch: callpc < func");

            stack.push_back(addr);

            if (isEntry(addr))
                return;

            if (decodePrologue(ksp, pc, addr, size, ra)) {
                if (!ra)
                    return;

                if (size <= 0) {
                    stack.push_back(unknown);
                    return;
                }

                pc = ra;
                ksp += size;
            } else {
                stack.push_back(unknown);
                return;
            }

            bool kernel = tc->getSystemPtr()->kernelStart <= pc &&
                pc <= tc->getSystemPtr()->kernelEnd;
            if (!kernel)
                return;

            if (stack.size() >= 1000)
                panic("unwinding too far");
        }

        panic("unwinding too far");
#endif
    }

    bool
    StackTrace::isEntry(Addr addr)
    {
#if 0
        if (addr == tc->readMiscReg(AlphaISA::IPR_PALtemp12))
            return true;

        if (addr == tc->readMiscReg(AlphaISA::IPR_PALtemp7))
            return true;

        if (addr == tc->readMiscReg(AlphaISA::IPR_PALtemp11))
            return true;

        if (addr == tc->readMiscReg(AlphaISA::IPR_PALtemp21))
            return true;

        if (addr == tc->readMiscReg(AlphaISA::IPR_PALtemp9))
            return true;

        if (addr == tc->readMiscReg(AlphaISA::IPR_PALtemp2))
            return true;
#endif
        return false;
    }

    bool
    StackTrace::decodeStack(MachInst inst, int &disp)
    {
        // lda $sp, -disp($sp)
        //
        // Opcode<31:26> == 0x08
        // RA<25:21> == 30
        // RB<20:16> == 30
        // Disp<15:0>
        const MachInst mem_mask = 0xffff0000;
        const MachInst lda_pattern = 0x23de0000;
        const MachInst lda_disp_mask = 0x0000ffff;

        // subq $sp, disp, $sp
        // addq $sp, disp, $sp
        //
        // Opcode<31:26> == 0x10
        // RA<25:21> == 30
        // Lit<20:13>
        // One<12> = 1
        // Func<11:5> == 0x20 (addq)
        // Func<11:5> == 0x29 (subq)
        // RC<4:0> == 30
        const MachInst intop_mask = 0xffe01fff;
        const MachInst addq_pattern = 0x43c0141e;
        const MachInst subq_pattern = 0x43c0153e;
        const MachInst intop_disp_mask = 0x001fe000;
        const int intop_disp_shift = 13;

        if ((inst & mem_mask) == lda_pattern)
            disp = -sext<16>(inst & lda_disp_mask);
        else if ((inst & intop_mask) == addq_pattern)
            disp = -int((inst & intop_disp_mask) >> intop_disp_shift);
        else if ((inst & intop_mask) == subq_pattern)
            disp = int((inst & intop_disp_mask) >> intop_disp_shift);
        else
            return false;

        return true;
    }

    bool
    StackTrace::decodeSave(MachInst inst, int &reg, int &disp)
    {
        // lda $stq, disp($sp)
        //
        // Opcode<31:26> == 0x08
        // RA<25:21> == ?
        // RB<20:16> == 30
        // Disp<15:0>
        const MachInst stq_mask = 0xfc1f0000;
        const MachInst stq_pattern = 0xb41e0000;
        const MachInst stq_disp_mask = 0x0000ffff;
        const MachInst reg_mask = 0x03e00000;
        const int reg_shift = 21;

        if ((inst & stq_mask) == stq_pattern) {
            reg = (inst & reg_mask) >> reg_shift;
            disp = sext<16>(inst & stq_disp_mask);
        } else {
            return false;
        }

        return true;
    }

    /*
     * Decode the function prologue for the function we're in, and note
     * which registers are stored where, and how large the stack frame is.
     */
    bool
    StackTrace::decodePrologue(Addr sp, Addr callpc, Addr func,
                               int &size, Addr &ra)
    {
        size = 0;
        ra = 0;

        for (Addr pc = func; pc < callpc; pc += sizeof(MachInst)) {
            MachInst inst;
            CopyOut(tc, (uint8_t *)&inst, pc, sizeof(MachInst));

            int reg, disp;
            if (decodeStack(inst, disp)) {
                if (size) {
                    // panic("decoding frame size again");
                    return true;
                }
                size += disp;
            } else if (decodeSave(inst, reg, disp)) {
                if (!ra && reg == ReturnAddressReg) {
                    CopyOut(tc, (uint8_t *)&ra, sp + disp, sizeof(Addr));
                    if (!ra) {
                        // panic("no return address value pc=%#x\n", pc);
                        return false;
                    }
                }
            }
        }

        return true;
    }

#if TRACING_ON
    void
    StackTrace::dump()
    {
        StringWrap name(tc->getCpuPtr()->name());
        SymbolTable *symtab = tc->getSystemPtr()->kernelSymtab;

        DPRINTFN("------ Stack ------\n");

        string symbol;
        for (int i = 0, size = stack.size(); i < size; ++i) {
            Addr addr = stack[size - i - 1];
            if (addr == user)
                symbol = "user";
            else if (addr == console)
                symbol = "console";
            else if (addr == unknown)
                symbol = "unknown";
            else
                symtab->findSymbol(addr, symbol);

            DPRINTFN("%#x: %s\n", addr, symbol);
        }
    }
#endif
}