stacktrace.cc revision 7720:65d338a8dba4 
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
46ProcessInfo::ProcessInfo(ThreadContext *_tc)
47    : tc(_tc)
48{
49    Addr addr = 0;
50    VirtualPort *vp = tc->getVirtPort();
51    SymbolTable *symtab = tc->getSystemPtr()->kernelSymtab;
52
53    if (!symtab->findAddress("thread_info_size", addr))
54        panic("thread info not compiled into kernel\n");
55    thread_info_size = vp->readGtoH<int32_t>(addr);
56
57    if (!symtab->findAddress("task_struct_size", addr))
58        panic("thread info not compiled into kernel\n");
59    task_struct_size = vp->readGtoH<int32_t>(addr);
60
61    if (!symtab->findAddress("thread_info_task", addr))
62        panic("thread info not compiled into kernel\n");
63    task_off = vp->readGtoH<int32_t>(addr);
64
65    if (!symtab->findAddress("task_struct_pid", addr))
66        panic("thread info not compiled into kernel\n");
67    pid_off = vp->readGtoH<int32_t>(addr);
68
69    if (!symtab->findAddress("task_struct_comm", addr))
70        panic("thread info not compiled into kernel\n");
71    name_off = vp->readGtoH<int32_t>(addr);
72}
73
74Addr
75ProcessInfo::task(Addr ksp) const
76{
77    Addr base = ksp & ~0x3fff;
78    if (base == ULL(0xfffffc0000000000))
79        return 0;
80
81    Addr tsk;
82
83    VirtualPort *vp;
84
85    vp = tc->getVirtPort();
86    tsk = vp->readGtoH<Addr>(base + task_off);
87
88    return tsk;
89}
90
91int
92ProcessInfo::pid(Addr ksp) const
93{
94    Addr task = this->task(ksp);
95    if (!task)
96        return -1;
97
98    uint16_t pd;
99
100    VirtualPort *vp;
101
102    vp = tc->getVirtPort();
103    pd = vp->readGtoH<uint16_t>(task + pid_off);
104
105    return pd;
106}
107
108string
109ProcessInfo::name(Addr ksp) const
110{
111    Addr task = this->task(ksp);
112    if (!task)
113        return "console";
114
115    char comm[256];
116    CopyStringOut(tc, comm, task + name_off, sizeof(comm));
117    if (!comm[0])
118        return "startup";
119
120    return comm;
121}
122
123StackTrace::StackTrace()
124    : tc(0), stack(64)
125{
126}
127
128StackTrace::StackTrace(ThreadContext *_tc, StaticInstPtr inst)
129    : tc(0), stack(64)
130{
131    trace(_tc, inst);
132}
133
134StackTrace::~StackTrace()
135{
136}
137
138void
139StackTrace::trace(ThreadContext *_tc, bool is_call)
140{
141    tc = _tc;
142
143    System *sys = tc->getSystemPtr();
144
145    bool usermode =
146        (tc->readMiscRegNoEffect(IPR_DTB_CM) & 0x18) != 0;
147
148    Addr pc = tc->pcState().pc();
149    bool kernel = sys->kernelStart <= pc && pc <= sys->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 = sys->kernelSymtab;
162    Addr ksp = tc->readIntReg(StackPointerReg);
163    Addr bottom = ksp & ~0x3fff;
164
165    if (is_call) {
166        Addr addr;
167        if (!symtab->findNearestAddr(pc, addr))
168            panic("could not find address %#x", pc);
169
170        stack.push_back(addr);
171        pc = tc->pcState().pc();
172    }
173
174    while (ksp > bottom) {
175        Addr addr;
176        if (!symtab->findNearestAddr(pc, addr))
177            panic("could not find symbol for pc=%#x", pc);
178        assert(pc >= addr && "symbol botch: callpc < func");
179
180        stack.push_back(addr);
181
182        if (isEntry(addr))
183            return;
184
185        Addr ra;
186        int size;
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 = sys->kernelStart <= pc && pc <= sys->kernelEnd;
204        if (!kernel)
205            return;
206
207        if (stack.size() >= 1000)
208            panic("unwinding too far");
209    }
210
211    panic("unwinding too far");
212}
213
214bool
215StackTrace::isEntry(Addr addr)
216{
217    if (addr == tc->readMiscRegNoEffect(IPR_PALtemp12))
218        return true;
219
220    if (addr == tc->readMiscRegNoEffect(IPR_PALtemp7))
221        return true;
222
223    if (addr == tc->readMiscRegNoEffect(IPR_PALtemp11))
224        return true;
225
226    if (addr == tc->readMiscRegNoEffect(IPR_PALtemp21))
227        return true;
228
229    if (addr == tc->readMiscRegNoEffect(IPR_PALtemp9))
230        return true;
231
232    if (addr == tc->readMiscRegNoEffect(IPR_PALtemp2))
233        return true;
234
235    return false;
236}
237
238bool
239StackTrace::decodeStack(MachInst inst, int &disp)
240{
241    // lda $sp, -disp($sp)
242    //
243    // Opcode<31:26> == 0x08
244    // RA<25:21> == 30
245    // RB<20:16> == 30
246    // Disp<15:0>
247    const MachInst mem_mask = 0xffff0000;
248    const MachInst lda_pattern = 0x23de0000;
249    const MachInst lda_disp_mask = 0x0000ffff;
250
251    // subq $sp, disp, $sp
252    // addq $sp, disp, $sp
253    //
254    // Opcode<31:26> == 0x10
255    // RA<25:21> == 30
256    // Lit<20:13>
257    // One<12> = 1
258    // Func<11:5> == 0x20 (addq)
259    // Func<11:5> == 0x29 (subq)
260    // RC<4:0> == 30
261    const MachInst intop_mask = 0xffe01fff;
262    const MachInst addq_pattern = 0x43c0141e;
263    const MachInst subq_pattern = 0x43c0153e;
264    const MachInst intop_disp_mask = 0x001fe000;
265    const int intop_disp_shift = 13;
266
267    if ((inst & mem_mask) == lda_pattern)
268        disp = -sext<16>(inst & lda_disp_mask);
269    else if ((inst & intop_mask) == addq_pattern)
270        disp = -int((inst & intop_disp_mask) >> intop_disp_shift);
271    else if ((inst & intop_mask) == subq_pattern)
272        disp = int((inst & intop_disp_mask) >> intop_disp_shift);
273    else
274        return false;
275
276    return true;
277}
278
279bool
280StackTrace::decodeSave(MachInst inst, int &reg, int &disp)
281{
282    // lda $stq, disp($sp)
283    //
284    // Opcode<31:26> == 0x08
285    // RA<25:21> == ?
286    // RB<20:16> == 30
287    // Disp<15:0>
288    const MachInst stq_mask = 0xfc1f0000;
289    const MachInst stq_pattern = 0xb41e0000;
290    const MachInst stq_disp_mask = 0x0000ffff;
291    const MachInst reg_mask = 0x03e00000;
292    const int reg_shift = 21;
293
294    if ((inst & stq_mask) == stq_pattern) {
295        reg = (inst & reg_mask) >> reg_shift;
296        disp = sext<16>(inst & stq_disp_mask);
297    } else {
298        return false;
299    }
300
301    return true;
302}
303
304/*
305 * Decode the function prologue for the function we're in, and note
306 * which registers are stored where, and how large the stack frame is.
307 */
308bool
309StackTrace::decodePrologue(Addr sp, Addr callpc, Addr func, int &size,
310                           Addr &ra)
311{
312    size = 0;
313    ra = 0;
314
315    for (Addr pc = func; pc < callpc; pc += sizeof(MachInst)) {
316        MachInst inst;
317        CopyOut(tc, (uint8_t *)&inst, pc, sizeof(MachInst));
318
319        int reg, disp;
320        if (decodeStack(inst, disp)) {
321            if (size) {
322                // panic("decoding frame size again");
323                return true;
324            }
325            size += disp;
326        } else if (decodeSave(inst, reg, disp)) {
327            if (!ra && reg == ReturnAddressReg) {
328                CopyOut(tc, (uint8_t *)&ra, sp + disp, sizeof(Addr));
329                if (!ra) {
330                    // panic("no return address value pc=%#x\n", pc);
331                    return false;
332                }
333            }
334        }
335    }
336
337    return true;
338}
339
340#if TRACING_ON
341void
342StackTrace::dump()
343{
344    StringWrap name(tc->getCpuPtr()->name());
345    SymbolTable *symtab = tc->getSystemPtr()->kernelSymtab;
346
347    DPRINTFN("------ Stack ------\n");
348
349    string symbol;
350    for (int i = 0, size = stack.size(); i < size; ++i) {
351        Addr addr = stack[size - i - 1];
352        if (addr == user)
353            symbol = "user";
354        else if (addr == console)
355            symbol = "console";
356        else if (addr == unknown)
357            symbol = "unknown";
358        else
359            symtab->findSymbol(addr, symbol);
360
361        DPRINTFN("%#x: %s\n", addr, symbol);
362    }
363}
364#endif
365
366} // namespace AlphaISA
367