stacktrace.cc revision 12644:ee5e0c83e7fb 
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 "arch/alpha/stacktrace.hh"
32
33#include <string>
34
35#include "arch/alpha/isa_traits.hh"
36#include "arch/alpha/vtophys.hh"
37#include "base/bitfield.hh"
38#include "base/trace.hh"
39#include "cpu/base.hh"
40#include "cpu/thread_context.hh"
41#include "mem/fs_translating_port_proxy.hh"
42#include "sim/system.hh"
43
44using namespace std;
45
46namespace AlphaISA {
47
48ProcessInfo::ProcessInfo(ThreadContext *_tc)
49    : tc(_tc)
50{
51    Addr addr = 0;
52    FSTranslatingPortProxy &vp = tc->getVirtProxy();
53    SymbolTable *symtab = tc->getSystemPtr()->kernelSymtab;
54
55    if (!symtab->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 (!symtab->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 (!symtab->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 (!symtab->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 (!symtab->findAddress("task_struct_comm", addr))
72        panic("thread info not compiled into kernel\n");
73    name_off = vp.readGtoH<int32_t>(addr);
74}
75
76Addr
77ProcessInfo::task(Addr ksp) const
78{
79    Addr base = ksp & ~0x3fff;
80    if (base == ULL(0xfffffc0000000000))
81        return 0;
82
83    Addr tsk;
84
85    FSTranslatingPortProxy &vp = tc->getVirtProxy();
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    FSTranslatingPortProxy &vp = tc->getVirtProxy();
101    pd = vp.readGtoH<uint16_t>(task + pid_off);
102
103    return pd;
104}
105
106string
107ProcessInfo::name(Addr ksp) const
108{
109    Addr task = this->task(ksp);
110    if (!task)
111        return "console";
112
113    char comm[256];
114    CopyStringOut(tc, comm, task + name_off, sizeof(comm));
115    if (!comm[0])
116        return "startup";
117
118    return comm;
119}
120
121StackTrace::StackTrace()
122    : tc(0), stack(64)
123{
124}
125
126StackTrace::StackTrace(ThreadContext *_tc, const StaticInstPtr &inst)
127    : tc(0), stack(64)
128{
129    trace(_tc, inst);
130}
131
132StackTrace::~StackTrace()
133{
134}
135
136void
137StackTrace::trace(ThreadContext *_tc, bool is_call)
138{
139    tc = _tc;
140
141    System *sys = tc->getSystemPtr();
142
143    bool usermode =
144        (tc->readMiscRegNoEffect(IPR_DTB_CM) & 0x18) != 0;
145
146    Addr pc = tc->pcState().npc();
147    bool kernel = sys->kernelStart <= pc && pc <= sys->kernelEnd;
148
149    if (usermode) {
150        stack.push_back(user);
151        return;
152    }
153
154    if (!kernel) {
155        stack.push_back(console);
156        return;
157    }
158
159    SymbolTable *symtab = sys->kernelSymtab;
160    Addr ksp = tc->readIntReg(StackPointerReg);
161    Addr bottom = ksp & ~0x3fff;
162
163    if (is_call) {
164        Addr addr;
165        if (!symtab->findNearestAddr(pc, addr))
166            panic("could not find address %#x", pc);
167
168        stack.push_back(addr);
169        pc = tc->pcState().pc();
170    }
171
172    while (ksp > bottom) {
173        Addr addr;
174        if (!symtab->findNearestAddr(pc, addr))
175            panic("could not find symbol for pc=%#x", pc);
176        assert(pc >= addr && "symbol botch: callpc < func");
177
178        stack.push_back(addr);
179
180        if (isEntry(addr))
181            return;
182
183        Addr ra;
184        int size;
185        if (decodePrologue(ksp, pc, addr, size, ra)) {
186            if (!ra)
187                return;
188
189            if (size <= 0) {
190                stack.push_back(unknown);
191                return;
192            }
193
194            pc = ra;
195            ksp += size;
196        } else {
197            stack.push_back(unknown);
198            return;
199        }
200
201        kernel = sys->kernelStart <= pc && pc <= sys->kernelEnd;
202        if (!kernel)
203            return;
204
205        if (stack.size() >= 1000)
206            panic("unwinding too far");
207    }
208
209    panic("unwinding too far");
210}
211
212bool
213StackTrace::isEntry(Addr addr)
214{
215    if (addr == tc->readMiscRegNoEffect(IPR_PALtemp12))
216        return true;
217
218    if (addr == tc->readMiscRegNoEffect(IPR_PALtemp7))
219        return true;
220
221    if (addr == tc->readMiscRegNoEffect(IPR_PALtemp11))
222        return true;
223
224    if (addr == tc->readMiscRegNoEffect(IPR_PALtemp21))
225        return true;
226
227    if (addr == tc->readMiscRegNoEffect(IPR_PALtemp9))
228        return true;
229
230    if (addr == tc->readMiscRegNoEffect(IPR_PALtemp2))
231        return true;
232
233    return false;
234}
235
236bool
237StackTrace::decodeStack(MachInst inst, int &disp)
238{
239    // lda $sp, -disp($sp)
240    //
241    // Opcode<31:26> == 0x08
242    // RA<25:21> == 30
243    // RB<20:16> == 30
244    // Disp<15:0>
245    const MachInst mem_mask = 0xffff0000;
246    const MachInst lda_pattern = 0x23de0000;
247    const MachInst lda_disp_mask = 0x0000ffff;
248
249    // subq $sp, disp, $sp
250    // addq $sp, disp, $sp
251    //
252    // Opcode<31:26> == 0x10
253    // RA<25:21> == 30
254    // Lit<20:13>
255    // One<12> = 1
256    // Func<11:5> == 0x20 (addq)
257    // Func<11:5> == 0x29 (subq)
258    // RC<4:0> == 30
259    const MachInst intop_mask = 0xffe01fff;
260    const MachInst addq_pattern = 0x43c0141e;
261    const MachInst subq_pattern = 0x43c0153e;
262    const MachInst intop_disp_mask = 0x001fe000;
263    const int intop_disp_shift = 13;
264
265    if ((inst & mem_mask) == lda_pattern)
266        disp = -sext<16>(inst & lda_disp_mask);
267    else if ((inst & intop_mask) == addq_pattern)
268        disp = -int((inst & intop_disp_mask) >> intop_disp_shift);
269    else if ((inst & intop_mask) == subq_pattern)
270        disp = int((inst & intop_disp_mask) >> intop_disp_shift);
271    else
272        return false;
273
274    return true;
275}
276
277bool
278StackTrace::decodeSave(MachInst inst, int &reg, int &disp)
279{
280    // lda $stq, disp($sp)
281    //
282    // Opcode<31:26> == 0x08
283    // RA<25:21> == ?
284    // RB<20:16> == 30
285    // Disp<15:0>
286    const MachInst stq_mask = 0xfc1f0000;
287    const MachInst stq_pattern = 0xb41e0000;
288    const MachInst stq_disp_mask = 0x0000ffff;
289    const MachInst reg_mask = 0x03e00000;
290    const int reg_shift = 21;
291
292    if ((inst & stq_mask) == stq_pattern) {
293        reg = (inst & reg_mask) >> reg_shift;
294        disp = sext<16>(inst & stq_disp_mask);
295    } else {
296        return false;
297    }
298
299    return true;
300}
301
302/*
303 * Decode the function prologue for the function we're in, and note
304 * which registers are stored where, and how large the stack frame is.
305 */
306bool
307StackTrace::decodePrologue(Addr sp, Addr callpc, Addr func, int &size,
308                           Addr &ra)
309{
310    size = 0;
311    ra = 0;
312
313    for (Addr pc = func; pc < callpc; pc += sizeof(MachInst)) {
314        MachInst inst;
315        CopyOut(tc, (uint8_t *)&inst, pc, sizeof(MachInst));
316
317        int reg, disp;
318        if (decodeStack(inst, disp)) {
319            if (size) {
320                // panic("decoding frame size again");
321                return true;
322            }
323            size += disp;
324        } else if (decodeSave(inst, reg, disp)) {
325            if (!ra && reg == ReturnAddressReg) {
326                CopyOut(tc, (uint8_t *)&ra, sp + disp, sizeof(Addr));
327                if (!ra) {
328                    // panic("no return address value pc=%#x\n", pc);
329                    return false;
330                }
331            }
332        }
333    }
334
335    return true;
336}
337
338#if TRACING_ON
339void
340StackTrace::dump()
341{
342    StringWrap name(tc->getCpuPtr()->name());
343    SymbolTable *symtab = tc->getSystemPtr()->kernelSymtab;
344
345    DPRINTFN("------ Stack ------\n");
346
347    string symbol;
348    for (int i = 0, size = stack.size(); i < size; ++i) {
349        Addr addr = stack[size - i - 1];
350        if (addr == user)
351            symbol = "user";
352        else if (addr == console)
353            symbol = "console";
354        else if (addr == unknown)
355            symbol = "unknown";
356        else
357            symtab->findSymbol(addr, symbol);
358
359        DPRINTFN("%#x: %s\n", addr, symbol);
360    }
361}
362#endif
363
364} // namespace AlphaISA
365