stacktrace.cc revision 2632:1bb2f91485ea 
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
29#include <string>
30
31#include "arch/alpha/isa_traits.hh"
32#include "arch/alpha/stacktrace.hh"
33#include "arch/alpha/vtophys.hh"
34#include "base/bitfield.hh"
35#include "base/trace.hh"
36#include "cpu/base.hh"
37#include "cpu/exec_context.hh"
38#include "sim/system.hh"
39
40using namespace std;
41using namespace AlphaISA;
42
43ProcessInfo::ProcessInfo(ExecContext *_xc)
44    : xc(_xc)
45{
46    Addr addr = 0;
47
48    if (!xc->getSystemPtr()->kernelSymtab->findAddress("thread_info_size", addr))
49        panic("thread info not compiled into kernel\n");
50    thread_info_size = gtoh(xc->getVirtPort()->read<int32_t>(addr));
51
52    if (!xc->getSystemPtr()->kernelSymtab->findAddress("task_struct_size", addr))
53        panic("thread info not compiled into kernel\n");
54    task_struct_size = gtoh(xc->getVirtPort()->read<int32_t>(addr));
55
56    if (!xc->getSystemPtr()->kernelSymtab->findAddress("thread_info_task", addr))
57        panic("thread info not compiled into kernel\n");
58    task_off = gtoh(xc->getVirtPort()->read<int32_t>(addr));
59
60    if (!xc->getSystemPtr()->kernelSymtab->findAddress("task_struct_pid", addr))
61        panic("thread info not compiled into kernel\n");
62    pid_off = gtoh(xc->getVirtPort()->read<int32_t>(addr));
63
64    if (!xc->getSystemPtr()->kernelSymtab->findAddress("task_struct_comm", addr))
65        panic("thread info not compiled into kernel\n");
66    name_off = gtoh(xc->getVirtPort()->read<int32_t>(addr));
67}
68
69Addr
70ProcessInfo::task(Addr ksp) const
71{
72    Addr base = ksp & ~0x3fff;
73    if (base == ULL(0xfffffc0000000000))
74        return 0;
75
76    return gtoh(xc->getVirtPort()->read<Addr>(base + task_off));
77}
78
79int
80ProcessInfo::pid(Addr ksp) const
81{
82    Addr task = this->task(ksp);
83    if (!task)
84        return -1;
85
86    return gtoh(xc->getVirtPort()->read<uint16_t>(task + pid_off));
87}
88
89string
90ProcessInfo::name(Addr ksp) const
91{
92    Addr task = this->task(ksp);
93    if (!task)
94        return "console";
95
96    char comm[256];
97    CopyStringOut(xc, comm, task + name_off, sizeof(comm));
98    if (!comm[0])
99        return "startup";
100
101    return comm;
102}
103
104StackTrace::StackTrace()
105    : xc(0), stack(64)
106{
107}
108
109StackTrace::StackTrace(ExecContext *_xc, StaticInstPtr inst)
110    : xc(0), stack(64)
111{
112    trace(_xc, inst);
113}
114
115StackTrace::~StackTrace()
116{
117}
118
119void
120StackTrace::trace(ExecContext *_xc, bool is_call)
121{
122    xc = _xc;
123
124    bool usermode = (xc->readMiscReg(AlphaISA::IPR_DTB_CM) & 0x18) != 0;
125
126    Addr pc = xc->readNextPC();
127    bool kernel = xc->getSystemPtr()->kernelStart <= pc &&
128        pc <= xc->getSystemPtr()->kernelEnd;
129
130    if (usermode) {
131        stack.push_back(user);
132        return;
133    }
134
135    if (!kernel) {
136        stack.push_back(console);
137        return;
138    }
139
140    SymbolTable *symtab = xc->getSystemPtr()->kernelSymtab;
141    Addr ksp = xc->readIntReg(TheISA::StackPointerReg);
142    Addr bottom = ksp & ~0x3fff;
143    Addr addr;
144
145    if (is_call) {
146        if (!symtab->findNearestAddr(pc, addr))
147            panic("could not find address %#x", pc);
148
149        stack.push_back(addr);
150        pc = xc->readPC();
151    }
152
153    Addr ra;
154    int size;
155
156    while (ksp > bottom) {
157        if (!symtab->findNearestAddr(pc, addr))
158            panic("could not find symbol for pc=%#x", pc);
159        assert(pc >= addr && "symbol botch: callpc < func");
160
161        stack.push_back(addr);
162
163        if (isEntry(addr))
164            return;
165
166        if (decodePrologue(ksp, pc, addr, size, ra)) {
167            if (!ra)
168                return;
169
170            if (size <= 0) {
171                stack.push_back(unknown);
172                return;
173            }
174
175            pc = ra;
176            ksp += size;
177        } else {
178            stack.push_back(unknown);
179            return;
180        }
181
182        bool kernel = xc->getSystemPtr()->kernelStart <= pc &&
183            pc <= xc->getSystemPtr()->kernelEnd;
184        if (!kernel)
185            return;
186
187        if (stack.size() >= 1000)
188            panic("unwinding too far");
189    }
190
191    panic("unwinding too far");
192}
193
194bool
195StackTrace::isEntry(Addr addr)
196{
197    if (addr == xc->readMiscReg(AlphaISA::IPR_PALtemp12))
198        return true;
199
200    if (addr == xc->readMiscReg(AlphaISA::IPR_PALtemp7))
201        return true;
202
203    if (addr == xc->readMiscReg(AlphaISA::IPR_PALtemp11))
204        return true;
205
206    if (addr == xc->readMiscReg(AlphaISA::IPR_PALtemp21))
207        return true;
208
209    if (addr == xc->readMiscReg(AlphaISA::IPR_PALtemp9))
210        return true;
211
212    if (addr == xc->readMiscReg(AlphaISA::IPR_PALtemp2))
213        return true;
214
215    return false;
216}
217
218bool
219StackTrace::decodeStack(MachInst inst, int &disp)
220{
221    // lda $sp, -disp($sp)
222    //
223    // Opcode<31:26> == 0x08
224    // RA<25:21> == 30
225    // RB<20:16> == 30
226    // Disp<15:0>
227    const MachInst mem_mask = 0xffff0000;
228    const MachInst lda_pattern = 0x23de0000;
229    const MachInst lda_disp_mask = 0x0000ffff;
230
231    // subq $sp, disp, $sp
232    // addq $sp, disp, $sp
233    //
234    // Opcode<31:26> == 0x10
235    // RA<25:21> == 30
236    // Lit<20:13>
237    // One<12> = 1
238    // Func<11:5> == 0x20 (addq)
239    // Func<11:5> == 0x29 (subq)
240    // RC<4:0> == 30
241    const MachInst intop_mask = 0xffe01fff;
242    const MachInst addq_pattern = 0x43c0141e;
243    const MachInst subq_pattern = 0x43c0153e;
244    const MachInst intop_disp_mask = 0x001fe000;
245    const int intop_disp_shift = 13;
246
247    if ((inst & mem_mask) == lda_pattern)
248        disp = -sext<16>(inst & lda_disp_mask);
249    else if ((inst & intop_mask) == addq_pattern)
250        disp = -int((inst & intop_disp_mask) >> intop_disp_shift);
251    else if ((inst & intop_mask) == subq_pattern)
252        disp = int((inst & intop_disp_mask) >> intop_disp_shift);
253    else
254        return false;
255
256    return true;
257}
258
259bool
260StackTrace::decodeSave(MachInst inst, int &reg, int &disp)
261{
262    // lda $stq, disp($sp)
263    //
264    // Opcode<31:26> == 0x08
265    // RA<25:21> == ?
266    // RB<20:16> == 30
267    // Disp<15:0>
268    const MachInst stq_mask = 0xfc1f0000;
269    const MachInst stq_pattern = 0xb41e0000;
270    const MachInst stq_disp_mask = 0x0000ffff;
271    const MachInst reg_mask = 0x03e00000;
272    const int reg_shift = 21;
273
274    if ((inst & stq_mask) == stq_pattern) {
275        reg = (inst & reg_mask) >> reg_shift;
276        disp = sext<16>(inst & stq_disp_mask);
277    } else {
278        return false;
279    }
280
281    return true;
282}
283
284/*
285 * Decode the function prologue for the function we're in, and note
286 * which registers are stored where, and how large the stack frame is.
287 */
288bool
289StackTrace::decodePrologue(Addr sp, Addr callpc, Addr func,
290                           int &size, Addr &ra)
291{
292    size = 0;
293    ra = 0;
294
295    for (Addr pc = func; pc < callpc; pc += sizeof(MachInst)) {
296        MachInst inst;
297        CopyOut(xc, (uint8_t *)&inst, pc, sizeof(MachInst));
298
299        int reg, disp;
300        if (decodeStack(inst, disp)) {
301            if (size) {
302                // panic("decoding frame size again");
303                return true;
304            }
305            size += disp;
306        } else if (decodeSave(inst, reg, disp)) {
307            if (!ra && reg == ReturnAddressReg) {
308                CopyOut(xc, (uint8_t *)&ra, sp + disp, sizeof(Addr));
309                if (!ra) {
310                    // panic("no return address value pc=%#x\n", pc);
311                    return false;
312                }
313            }
314        }
315    }
316
317    return true;
318}
319
320#if TRACING_ON
321void
322StackTrace::dump()
323{
324    StringWrap name(xc->getCpuPtr()->name());
325    SymbolTable *symtab = xc->getSystemPtr()->kernelSymtab;
326
327    DPRINTFN("------ Stack ------\n");
328
329    string symbol;
330    for (int i = 0, size = stack.size(); i < size; ++i) {
331        Addr addr = stack[size - i - 1];
332        if (addr == user)
333            symbol = "user";
334        else if (addr == console)
335            symbol = "console";
336        else if (addr == unknown)
337            symbol = "unknown";
338        else
339            symtab->findSymbol(addr, symbol);
340
341        DPRINTFN("%#x: %s\n", addr, symbol);
342    }
343}
344#endif
345