stacktrace.cc revision 2684:71f3cabf891f 
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;
43using namespace AlphaISA;
44
45ProcessInfo::ProcessInfo(ThreadContext *_tc)
46    : tc(_tc)
47{
48    Addr addr = 0;
49
50    VirtualPort *vp;
51
52    vp = tc->getVirtPort();
53
54    if (!tc->getSystemPtr()->kernelSymtab->findAddress("thread_info_size", addr))
55        panic("thread info not compiled into kernel\n");
56    thread_info_size = vp->readGtoH<int32_t>(addr);
57
58    if (!tc->getSystemPtr()->kernelSymtab->findAddress("task_struct_size", addr))
59        panic("thread info not compiled into kernel\n");
60    task_struct_size = vp->readGtoH<int32_t>(addr);
61
62    if (!tc->getSystemPtr()->kernelSymtab->findAddress("thread_info_task", addr))
63        panic("thread info not compiled into kernel\n");
64    task_off = vp->readGtoH<int32_t>(addr);
65
66    if (!tc->getSystemPtr()->kernelSymtab->findAddress("task_struct_pid", addr))
67        panic("thread info not compiled into kernel\n");
68    pid_off = vp->readGtoH<int32_t>(addr);
69
70    if (!tc->getSystemPtr()->kernelSymtab->findAddress("task_struct_comm", addr))
71        panic("thread info not compiled into kernel\n");
72    name_off = vp->readGtoH<int32_t>(addr);
73
74    tc->delVirtPort(vp);
75}
76
77Addr
78ProcessInfo::task(Addr ksp) const
79{
80    Addr base = ksp & ~0x3fff;
81    if (base == ULL(0xfffffc0000000000))
82        return 0;
83
84    Addr tsk;
85
86    VirtualPort *vp;
87
88    vp = tc->getVirtPort();
89    tsk = vp->readGtoH<Addr>(base + task_off);
90    tc->delVirtPort(vp);
91
92    return tsk;
93}
94
95int
96ProcessInfo::pid(Addr ksp) const
97{
98    Addr task = this->task(ksp);
99    if (!task)
100        return -1;
101
102    uint16_t pd;
103
104    VirtualPort *vp;
105
106    vp = tc->getVirtPort();
107    pd = vp->readGtoH<uint16_t>(task + pid_off);
108    tc->delVirtPort(vp);
109
110    return pd;
111}
112
113string
114ProcessInfo::name(Addr ksp) const
115{
116    Addr task = this->task(ksp);
117    if (!task)
118        return "console";
119
120    char comm[256];
121    CopyStringOut(tc, comm, task + name_off, sizeof(comm));
122    if (!comm[0])
123        return "startup";
124
125    return comm;
126}
127
128StackTrace::StackTrace()
129    : tc(0), stack(64)
130{
131}
132
133StackTrace::StackTrace(ThreadContext *_tc, StaticInstPtr inst)
134    : tc(0), stack(64)
135{
136    trace(_tc, inst);
137}
138
139StackTrace::~StackTrace()
140{
141}
142
143void
144StackTrace::trace(ThreadContext *_tc, bool is_call)
145{
146    tc = _tc;
147
148    bool usermode = (tc->readMiscReg(AlphaISA::IPR_DTB_CM) & 0x18) != 0;
149
150    Addr pc = tc->readNextPC();
151    bool kernel = tc->getSystemPtr()->kernelStart <= pc &&
152        pc <= tc->getSystemPtr()->kernelEnd;
153
154    if (usermode) {
155        stack.push_back(user);
156        return;
157    }
158
159    if (!kernel) {
160        stack.push_back(console);
161        return;
162    }
163
164    SymbolTable *symtab = tc->getSystemPtr()->kernelSymtab;
165    Addr ksp = tc->readIntReg(TheISA::StackPointerReg);
166    Addr bottom = ksp & ~0x3fff;
167    Addr addr;
168
169    if (is_call) {
170        if (!symtab->findNearestAddr(pc, addr))
171            panic("could not find address %#x", pc);
172
173        stack.push_back(addr);
174        pc = tc->readPC();
175    }
176
177    Addr ra;
178    int size;
179
180    while (ksp > bottom) {
181        if (!symtab->findNearestAddr(pc, addr))
182            panic("could not find symbol for pc=%#x", pc);
183        assert(pc >= addr && "symbol botch: callpc < func");
184
185        stack.push_back(addr);
186
187        if (isEntry(addr))
188            return;
189
190        if (decodePrologue(ksp, pc, addr, size, ra)) {
191            if (!ra)
192                return;
193
194            if (size <= 0) {
195                stack.push_back(unknown);
196                return;
197            }
198
199            pc = ra;
200            ksp += size;
201        } else {
202            stack.push_back(unknown);
203            return;
204        }
205
206        bool kernel = tc->getSystemPtr()->kernelStart <= pc &&
207            pc <= tc->getSystemPtr()->kernelEnd;
208        if (!kernel)
209            return;
210
211        if (stack.size() >= 1000)
212            panic("unwinding too far");
213    }
214
215    panic("unwinding too far");
216}
217
218bool
219StackTrace::isEntry(Addr addr)
220{
221    if (addr == tc->readMiscReg(AlphaISA::IPR_PALtemp12))
222        return true;
223
224    if (addr == tc->readMiscReg(AlphaISA::IPR_PALtemp7))
225        return true;
226
227    if (addr == tc->readMiscReg(AlphaISA::IPR_PALtemp11))
228        return true;
229
230    if (addr == tc->readMiscReg(AlphaISA::IPR_PALtemp21))
231        return true;
232
233    if (addr == tc->readMiscReg(AlphaISA::IPR_PALtemp9))
234        return true;
235
236    if (addr == tc->readMiscReg(AlphaISA::IPR_PALtemp2))
237        return true;
238
239    return false;
240}
241
242bool
243StackTrace::decodeStack(MachInst inst, int &disp)
244{
245    // lda $sp, -disp($sp)
246    //
247    // Opcode<31:26> == 0x08
248    // RA<25:21> == 30
249    // RB<20:16> == 30
250    // Disp<15:0>
251    const MachInst mem_mask = 0xffff0000;
252    const MachInst lda_pattern = 0x23de0000;
253    const MachInst lda_disp_mask = 0x0000ffff;
254
255    // subq $sp, disp, $sp
256    // addq $sp, disp, $sp
257    //
258    // Opcode<31:26> == 0x10
259    // RA<25:21> == 30
260    // Lit<20:13>
261    // One<12> = 1
262    // Func<11:5> == 0x20 (addq)
263    // Func<11:5> == 0x29 (subq)
264    // RC<4:0> == 30
265    const MachInst intop_mask = 0xffe01fff;
266    const MachInst addq_pattern = 0x43c0141e;
267    const MachInst subq_pattern = 0x43c0153e;
268    const MachInst intop_disp_mask = 0x001fe000;
269    const int intop_disp_shift = 13;
270
271    if ((inst & mem_mask) == lda_pattern)
272        disp = -sext<16>(inst & lda_disp_mask);
273    else if ((inst & intop_mask) == addq_pattern)
274        disp = -int((inst & intop_disp_mask) >> intop_disp_shift);
275    else if ((inst & intop_mask) == subq_pattern)
276        disp = int((inst & intop_disp_mask) >> intop_disp_shift);
277    else
278        return false;
279
280    return true;
281}
282
283bool
284StackTrace::decodeSave(MachInst inst, int &reg, int &disp)
285{
286    // lda $stq, disp($sp)
287    //
288    // Opcode<31:26> == 0x08
289    // RA<25:21> == ?
290    // RB<20:16> == 30
291    // Disp<15:0>
292    const MachInst stq_mask = 0xfc1f0000;
293    const MachInst stq_pattern = 0xb41e0000;
294    const MachInst stq_disp_mask = 0x0000ffff;
295    const MachInst reg_mask = 0x03e00000;
296    const int reg_shift = 21;
297
298    if ((inst & stq_mask) == stq_pattern) {
299        reg = (inst & reg_mask) >> reg_shift;
300        disp = sext<16>(inst & stq_disp_mask);
301    } else {
302        return false;
303    }
304
305    return true;
306}
307
308/*
309 * Decode the function prologue for the function we're in, and note
310 * which registers are stored where, and how large the stack frame is.
311 */
312bool
313StackTrace::decodePrologue(Addr sp, Addr callpc, Addr func,
314                           int &size, Addr &ra)
315{
316    size = 0;
317    ra = 0;
318
319    for (Addr pc = func; pc < callpc; pc += sizeof(MachInst)) {
320        MachInst inst;
321        CopyOut(tc, (uint8_t *)&inst, pc, sizeof(MachInst));
322
323        int reg, disp;
324        if (decodeStack(inst, disp)) {
325            if (size) {
326                // panic("decoding frame size again");
327                return true;
328            }
329            size += disp;
330        } else if (decodeSave(inst, reg, disp)) {
331            if (!ra && reg == ReturnAddressReg) {
332                CopyOut(tc, (uint8_t *)&ra, sp + disp, sizeof(Addr));
333                if (!ra) {
334                    // panic("no return address value pc=%#x\n", pc);
335                    return false;
336                }
337            }
338        }
339    }
340
341    return true;
342}
343
344#if TRACING_ON
345void
346StackTrace::dump()
347{
348    StringWrap name(tc->getCpuPtr()->name());
349    SymbolTable *symtab = tc->getSystemPtr()->kernelSymtab;
350
351    DPRINTFN("------ Stack ------\n");
352
353    string symbol;
354    for (int i = 0, size = stack.size(); i < size; ++i) {
355        Addr addr = stack[size - i - 1];
356        if (addr == user)
357            symbol = "user";
358        else if (addr == console)
359            symbol = "console";
360        else if (addr == unknown)
361            symbol = "unknown";
362        else
363            symtab->findSymbol(addr, symbol);
364
365        DPRINTFN("%#x: %s\n", addr, symbol);
366    }
367}
368#endif
369