stacktrace.cc revision 5568:d14250d688d2 
1/*
2 * Copyright (c) 2005 The Regents of The University of Michigan
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * Authors: Nathan Binkert
29 */
30
31#include <string>
32
33#include "arch/alpha/isa_traits.hh"
34#include "arch/alpha/stacktrace.hh"
35#include "arch/alpha/vtophys.hh"
36#include "base/bitfield.hh"
37#include "base/trace.hh"
38#include "cpu/base.hh"
39#include "cpu/thread_context.hh"
40#include "sim/system.hh"
41
42using namespace std;
43
44namespace AlphaISA
45{
46    ProcessInfo::ProcessInfo(ThreadContext *_tc)
47        : tc(_tc)
48    {
49        Addr addr = 0;
50
51        VirtualPort *vp;
52
53        vp = tc->getVirtPort();
54
55        if (!tc->getSystemPtr()->kernelSymtab->findAddress("thread_info_size", addr))
56            panic("thread info not compiled into kernel\n");
57        thread_info_size = vp->readGtoH<int32_t>(addr);
58
59        if (!tc->getSystemPtr()->kernelSymtab->findAddress("task_struct_size", addr))
60            panic("thread info not compiled into kernel\n");
61        task_struct_size = vp->readGtoH<int32_t>(addr);
62
63        if (!tc->getSystemPtr()->kernelSymtab->findAddress("thread_info_task", addr))
64            panic("thread info not compiled into kernel\n");
65        task_off = vp->readGtoH<int32_t>(addr);
66
67        if (!tc->getSystemPtr()->kernelSymtab->findAddress("task_struct_pid", addr))
68            panic("thread info not compiled into kernel\n");
69        pid_off = vp->readGtoH<int32_t>(addr);
70
71        if (!tc->getSystemPtr()->kernelSymtab->findAddress("task_struct_comm", addr))
72            panic("thread info not compiled into kernel\n");
73        name_off = vp->readGtoH<int32_t>(addr);
74    }
75
76    Addr
77    ProcessInfo::task(Addr ksp) const
78    {
79        Addr base = ksp & ~0x3fff;
80        if (base == ULL(0xfffffc0000000000))
81            return 0;
82
83        Addr tsk;
84
85        VirtualPort *vp;
86
87        vp = tc->getVirtPort();
88        tsk = vp->readGtoH<Addr>(base + task_off);
89
90        return tsk;
91    }
92
93    int
94    ProcessInfo::pid(Addr ksp) const
95    {
96        Addr task = this->task(ksp);
97        if (!task)
98            return -1;
99
100        uint16_t pd;
101
102        VirtualPort *vp;
103
104        vp = tc->getVirtPort();
105        pd = vp->readGtoH<uint16_t>(task + pid_off);
106
107        return pd;
108    }
109
110    string
111    ProcessInfo::name(Addr ksp) const
112    {
113        Addr task = this->task(ksp);
114        if (!task)
115            return "console";
116
117        char comm[256];
118        CopyStringOut(tc, comm, task + name_off, sizeof(comm));
119        if (!comm[0])
120            return "startup";
121
122        return comm;
123    }
124
125    StackTrace::StackTrace()
126        : tc(0), stack(64)
127    {
128    }
129
130    StackTrace::StackTrace(ThreadContext *_tc, StaticInstPtr inst)
131        : tc(0), stack(64)
132    {
133        trace(_tc, inst);
134    }
135
136    StackTrace::~StackTrace()
137    {
138    }
139
140    void
141    StackTrace::trace(ThreadContext *_tc, bool is_call)
142    {
143        tc = _tc;
144
145        bool usermode = (tc->readMiscRegNoEffect(IPR_DTB_CM) & 0x18) != 0;
146
147        Addr pc = tc->readNextPC();
148        bool kernel = tc->getSystemPtr()->kernelStart <= pc &&
149            pc <= tc->getSystemPtr()->kernelEnd;
150
151        if (usermode) {
152            stack.push_back(user);
153            return;
154        }
155
156        if (!kernel) {
157            stack.push_back(console);
158            return;
159        }
160
161        SymbolTable *symtab = tc->getSystemPtr()->kernelSymtab;
162        Addr ksp = tc->readIntReg(StackPointerReg);
163        Addr bottom = ksp & ~0x3fff;
164        Addr addr;
165
166        if (is_call) {
167            if (!symtab->findNearestAddr(pc, addr))
168                panic("could not find address %#x", pc);
169
170            stack.push_back(addr);
171            pc = tc->readPC();
172        }
173
174        Addr ra;
175        int size;
176
177        while (ksp > bottom) {
178            if (!symtab->findNearestAddr(pc, addr))
179                panic("could not find symbol for pc=%#x", pc);
180            assert(pc >= addr && "symbol botch: callpc < func");
181
182            stack.push_back(addr);
183
184            if (isEntry(addr))
185                return;
186
187            if (decodePrologue(ksp, pc, addr, size, ra)) {
188                if (!ra)
189                    return;
190
191                if (size <= 0) {
192                    stack.push_back(unknown);
193                    return;
194                }
195
196                pc = ra;
197                ksp += size;
198            } else {
199                stack.push_back(unknown);
200                return;
201            }
202
203            bool kernel = tc->getSystemPtr()->kernelStart <= pc &&
204                pc <= tc->getSystemPtr()->kernelEnd;
205            if (!kernel)
206                return;
207
208            if (stack.size() >= 1000)
209                panic("unwinding too far");
210        }
211
212        panic("unwinding too far");
213    }
214
215    bool
216    StackTrace::isEntry(Addr addr)
217    {
218        if (addr == tc->readMiscRegNoEffect(IPR_PALtemp12))
219            return true;
220
221        if (addr == tc->readMiscRegNoEffect(IPR_PALtemp7))
222            return true;
223
224        if (addr == tc->readMiscRegNoEffect(IPR_PALtemp11))
225            return true;
226
227        if (addr == tc->readMiscRegNoEffect(IPR_PALtemp21))
228            return true;
229
230        if (addr == tc->readMiscRegNoEffect(IPR_PALtemp9))
231            return true;
232
233        if (addr == tc->readMiscRegNoEffect(IPR_PALtemp2))
234            return true;
235
236        return false;
237    }
238
239    bool
240    StackTrace::decodeStack(MachInst inst, int &disp)
241    {
242        // lda $sp, -disp($sp)
243        //
244        // Opcode<31:26> == 0x08
245        // RA<25:21> == 30
246        // RB<20:16> == 30
247        // Disp<15:0>
248        const MachInst mem_mask = 0xffff0000;
249        const MachInst lda_pattern = 0x23de0000;
250        const MachInst lda_disp_mask = 0x0000ffff;
251
252        // subq $sp, disp, $sp
253        // addq $sp, disp, $sp
254        //
255        // Opcode<31:26> == 0x10
256        // RA<25:21> == 30
257        // Lit<20:13>
258        // One<12> = 1
259        // Func<11:5> == 0x20 (addq)
260        // Func<11:5> == 0x29 (subq)
261        // RC<4:0> == 30
262        const MachInst intop_mask = 0xffe01fff;
263        const MachInst addq_pattern = 0x43c0141e;
264        const MachInst subq_pattern = 0x43c0153e;
265        const MachInst intop_disp_mask = 0x001fe000;
266        const int intop_disp_shift = 13;
267
268        if ((inst & mem_mask) == lda_pattern)
269            disp = -sext<16>(inst & lda_disp_mask);
270        else if ((inst & intop_mask) == addq_pattern)
271            disp = -int((inst & intop_disp_mask) >> intop_disp_shift);
272        else if ((inst & intop_mask) == subq_pattern)
273            disp = int((inst & intop_disp_mask) >> intop_disp_shift);
274        else
275            return false;
276
277        return true;
278    }
279
280    bool
281    StackTrace::decodeSave(MachInst inst, int &reg, int &disp)
282    {
283        // lda $stq, disp($sp)
284        //
285        // Opcode<31:26> == 0x08
286        // RA<25:21> == ?
287        // RB<20:16> == 30
288        // Disp<15:0>
289        const MachInst stq_mask = 0xfc1f0000;
290        const MachInst stq_pattern = 0xb41e0000;
291        const MachInst stq_disp_mask = 0x0000ffff;
292        const MachInst reg_mask = 0x03e00000;
293        const int reg_shift = 21;
294
295        if ((inst & stq_mask) == stq_pattern) {
296            reg = (inst & reg_mask) >> reg_shift;
297            disp = sext<16>(inst & stq_disp_mask);
298        } else {
299            return false;
300        }
301
302        return true;
303    }
304
305    /*
306     * Decode the function prologue for the function we're in, and note
307     * which registers are stored where, and how large the stack frame is.
308     */
309    bool
310    StackTrace::decodePrologue(Addr sp, Addr callpc, Addr func,
311                               int &size, Addr &ra)
312    {
313        size = 0;
314        ra = 0;
315
316        for (Addr pc = func; pc < callpc; pc += sizeof(MachInst)) {
317            MachInst inst;
318            CopyOut(tc, (uint8_t *)&inst, pc, sizeof(MachInst));
319
320            int reg, disp;
321            if (decodeStack(inst, disp)) {
322                if (size) {
323                    // panic("decoding frame size again");
324                    return true;
325                }
326                size += disp;
327            } else if (decodeSave(inst, reg, disp)) {
328                if (!ra && reg == ReturnAddressReg) {
329                    CopyOut(tc, (uint8_t *)&ra, sp + disp, sizeof(Addr));
330                    if (!ra) {
331                        // panic("no return address value pc=%#x\n", pc);
332                        return false;
333                    }
334                }
335            }
336        }
337
338        return true;
339    }
340
341#if TRACING_ON
342    void
343    StackTrace::dump()
344    {
345        StringWrap name(tc->getCpuPtr()->name());
346        SymbolTable *symtab = tc->getSystemPtr()->kernelSymtab;
347
348        DPRINTFN("------ Stack ------\n");
349
350        string symbol;
351        for (int i = 0, size = stack.size(); i < size; ++i) {
352            Addr addr = stack[size - i - 1];
353            if (addr == user)
354                symbol = "user";
355            else if (addr == console)
356                symbol = "console";
357            else if (addr == unknown)
358                symbol = "unknown";
359            else
360                symtab->findSymbol(addr, symbol);
361
362            DPRINTFN("%#x: %s\n", addr, symbol);
363        }
364    }
365#endif
366}
367