stacktrace.cc revision 7723:ee4ac00d0774 
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 "mem/vport.hh"
41#include "sim/system.hh"
42
43using namespace std;
44
45namespace AlphaISA {
46
47ProcessInfo::ProcessInfo(ThreadContext *_tc)
48    : tc(_tc)
49{
50    Addr addr = 0;
51    VirtualPort *vp = tc->getVirtPort();
52    SymbolTable *symtab = tc->getSystemPtr()->kernelSymtab;
53
54    if (!symtab->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 (!symtab->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 (!symtab->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 (!symtab->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 (!symtab->findAddress("task_struct_comm", addr))
71        panic("thread info not compiled into kernel\n");
72    name_off = vp->readGtoH<int32_t>(addr);
73}
74
75Addr
76ProcessInfo::task(Addr ksp) const
77{
78    Addr base = ksp & ~0x3fff;
79    if (base == ULL(0xfffffc0000000000))
80        return 0;
81
82    Addr tsk;
83
84    VirtualPort *vp;
85
86    vp = tc->getVirtPort();
87    tsk = vp->readGtoH<Addr>(base + task_off);
88
89    return tsk;
90}
91
92int
93ProcessInfo::pid(Addr ksp) const
94{
95    Addr task = this->task(ksp);
96    if (!task)
97        return -1;
98
99    uint16_t pd;
100
101    VirtualPort *vp;
102
103    vp = tc->getVirtPort();
104    pd = vp->readGtoH<uint16_t>(task + pid_off);
105
106    return pd;
107}
108
109string
110ProcessInfo::name(Addr ksp) const
111{
112    Addr task = this->task(ksp);
113    if (!task)
114        return "console";
115
116    char comm[256];
117    CopyStringOut(tc, comm, task + name_off, sizeof(comm));
118    if (!comm[0])
119        return "startup";
120
121    return comm;
122}
123
124StackTrace::StackTrace()
125    : tc(0), stack(64)
126{
127}
128
129StackTrace::StackTrace(ThreadContext *_tc, StaticInstPtr inst)
130    : tc(0), stack(64)
131{
132    trace(_tc, inst);
133}
134
135StackTrace::~StackTrace()
136{
137}
138
139void
140StackTrace::trace(ThreadContext *_tc, bool is_call)
141{
142    tc = _tc;
143
144    System *sys = tc->getSystemPtr();
145
146    bool usermode =
147        (tc->readMiscRegNoEffect(IPR_DTB_CM) & 0x18) != 0;
148
149    Addr pc = tc->pcState().pc();
150    bool kernel = sys->kernelStart <= pc && pc <= sys->kernelEnd;
151
152    if (usermode) {
153        stack.push_back(user);
154        return;
155    }
156
157    if (!kernel) {
158        stack.push_back(console);
159        return;
160    }
161
162    SymbolTable *symtab = sys->kernelSymtab;
163    Addr ksp = tc->readIntReg(StackPointerReg);
164    Addr bottom = ksp & ~0x3fff;
165
166    if (is_call) {
167        Addr addr;
168        if (!symtab->findNearestAddr(pc, addr))
169            panic("could not find address %#x", pc);
170
171        stack.push_back(addr);
172        pc = tc->pcState().pc();
173    }
174
175    while (ksp > bottom) {
176        Addr addr;
177        if (!symtab->findNearestAddr(pc, addr))
178            panic("could not find symbol for pc=%#x", pc);
179        assert(pc >= addr && "symbol botch: callpc < func");
180
181        stack.push_back(addr);
182
183        if (isEntry(addr))
184            return;
185
186        Addr ra;
187        int size;
188        if (decodePrologue(ksp, pc, addr, size, ra)) {
189            if (!ra)
190                return;
191
192            if (size <= 0) {
193                stack.push_back(unknown);
194                return;
195            }
196
197            pc = ra;
198            ksp += size;
199        } else {
200            stack.push_back(unknown);
201            return;
202        }
203
204        bool kernel = sys->kernelStart <= pc && pc <= sys->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
215bool
216StackTrace::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
239bool
240StackTrace::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
280bool
281StackTrace::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 */
309bool
310StackTrace::decodePrologue(Addr sp, Addr callpc, Addr func, int &size,
311                           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
342void
343StackTrace::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} // namespace AlphaISA
368