arch/alpha/stacktrace.cc

   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
  40 using namespace std;
  41 using namespace AlphaISA;
  42
  43 ProcessInfo::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 = *(int32_t *)vtomem(xc, addr, sizeof(int32_t));
  51
  52     if (!xc->getSystemPtr()->kernelSymtab->findAddress("task_struct_size", addr))
  53         panic("thread info not compiled into kernel\n");
  54     task_struct_size = *(int32_t *)vtomem(xc, addr, sizeof(int32_t));
  55
  56     if (!xc->getSystemPtr()->kernelSymtab->findAddress("thread_info_task", addr))
  57         panic("thread info not compiled into kernel\n");
  58     task_off = *(int32_t *)vtomem(xc, addr, sizeof(int32_t));
  59
  60     if (!xc->getSystemPtr()->kernelSymtab->findAddress("task_struct_pid", addr))
  61         panic("thread info not compiled into kernel\n");
  62     pid_off = *(int32_t *)vtomem(xc, addr, sizeof(int32_t));
  63
  64     if (!xc->getSystemPtr()->kernelSymtab->findAddress("task_struct_comm", addr))
  65         panic("thread info not compiled into kernel\n");
  66     name_off = *(int32_t *)vtomem(xc, addr, sizeof(int32_t));
  67 }
  68
  69 Addr
  70 ProcessInfo::task(Addr ksp) const
  71 {
  72     Addr base = ksp & ~0x3fff;
  73     if (base == ULL(0xfffffc0000000000))
  74         return 0;
  75
  76     Addr task;
  77     CopyOut(xc, &task, base + task_off, sizeof(task));
  78     return task;
  79 }
  80
  81 int
  82 ProcessInfo::pid(Addr ksp) const
  83 {
  84     Addr task = this->task(ksp);
  85     if (!task)
  86         return -1;
  87
  88     uint16_t pid;
  89     CopyOut(xc, &pid, task + pid_off, sizeof(pid));
  90     return pid;
  91 }
  92
  93 string
  94 ProcessInfo::name(Addr ksp) const
  95 {
  96     Addr task = this->task(ksp);
  97     if (!task)
  98         return "console";
  99
 100     char comm[256];
 101     CopyString(xc, comm, task + name_off, sizeof(comm));
 102     if (!comm[0])
 103         return "startup";
 104
 105     return comm;
 106 }
 107
 108 StackTrace::StackTrace()
 109     : xc(0), stack(64)
 110 {
 111 }
 112
 113 StackTrace::StackTrace(ExecContext *_xc, StaticInstPtr inst)
 114     : xc(0), stack(64)
 115 {
 116     trace(_xc, inst);
 117 }
 118
 119 StackTrace::~StackTrace()
 120 {
 121 }
 122
 123 void
 124 StackTrace::trace(ExecContext *_xc, bool is_call)
 125 {
 126     xc = _xc;
 127
 128     bool usermode = (xc->readMiscReg(AlphaISA::IPR_DTB_CM) & 0x18) != 0;
 129
 130     Addr pc = xc->readNextPC();
 131     bool kernel = xc->getSystemPtr()->kernelStart <= pc &&
 132         pc <= xc->getSystemPtr()->kernelEnd;
 133
 134     if (usermode) {
 135         stack.push_back(user);
 136         return;
 137     }
 138
 139     if (!kernel) {
 140         stack.push_back(console);
 141         return;
 142     }
 143
 144     SymbolTable *symtab = xc->getSystemPtr()->kernelSymtab;
 145     Addr ksp = xc->readIntReg(TheISA::StackPointerReg);
 146     Addr bottom = ksp & ~0x3fff;
 147     Addr addr;
 148
 149     if (is_call) {
 150         if (!symtab->findNearestAddr(pc, addr))
 151             panic("could not find address %#x", pc);
 152
 153         stack.push_back(addr);
 154         pc = xc->readPC();
 155     }
 156
 157     Addr ra;
 158     int size;
 159
 160     while (ksp > bottom) {
 161         if (!symtab->findNearestAddr(pc, addr))
 162             panic("could not find symbol for pc=%#x", pc);
 163         assert(pc >= addr && "symbol botch: callpc < func");
 164
 165         stack.push_back(addr);
 166
 167         if (isEntry(addr))
 168             return;
 169
 170         if (decodePrologue(ksp, pc, addr, size, ra)) {
 171             if (!ra)
 172                 return;
 173
 174             if (size <= 0) {
 175                 stack.push_back(unknown);
 176                 return;
 177             }
 178
 179             pc = ra;
 180             ksp += size;
 181         } else {
 182             stack.push_back(unknown);
 183             return;
 184         }
 185
 186         bool kernel = xc->getSystemPtr()->kernelStart <= pc &&
 187             pc <= xc->getSystemPtr()->kernelEnd;
 188         if (!kernel)
 189             return;
 190
 191         if (stack.size() >= 1000)
 192             panic("unwinding too far");
 193     }
 194
 195     panic("unwinding too far");
 196 }
 197
 198 bool
 199 StackTrace::isEntry(Addr addr)
 200 {
 201     if (addr == xc->readMiscReg(AlphaISA::IPR_PALtemp12))
 202         return true;
 203
 204     if (addr == xc->readMiscReg(AlphaISA::IPR_PALtemp7))
 205         return true;
 206
 207     if (addr == xc->readMiscReg(AlphaISA::IPR_PALtemp11))
 208         return true;
 209
 210     if (addr == xc->readMiscReg(AlphaISA::IPR_PALtemp21))
 211         return true;
 212
 213     if (addr == xc->readMiscReg(AlphaISA::IPR_PALtemp9))
 214         return true;
 215
 216     if (addr == xc->readMiscReg(AlphaISA::IPR_PALtemp2))
 217         return true;
 218
 219     return false;
 220 }
 221
 222 bool
 223 StackTrace::decodeStack(MachInst inst, int &disp)
 224 {
 225     // lda $sp, -disp($sp)
 226     //
 227     // Opcode<31:26> == 0x08
 228     // RA<25:21> == 30
 229     // RB<20:16> == 30
 230     // Disp<15:0>
 231     const MachInst mem_mask = 0xffff0000;
 232     const MachInst lda_pattern = 0x23de0000;
 233     const MachInst lda_disp_mask = 0x0000ffff;
 234
 235     // subq $sp, disp, $sp
 236     // addq $sp, disp, $sp
 237     //
 238     // Opcode<31:26> == 0x10
 239     // RA<25:21> == 30
 240     // Lit<20:13>
 241     // One<12> = 1
 242     // Func<11:5> == 0x20 (addq)
 243     // Func<11:5> == 0x29 (subq)
 244     // RC<4:0> == 30
 245     const MachInst intop_mask = 0xffe01fff;
 246     const MachInst addq_pattern = 0x43c0141e;
 247     const MachInst subq_pattern = 0x43c0153e;
 248     const MachInst intop_disp_mask = 0x001fe000;
 249     const int intop_disp_shift = 13;
 250
 251     if ((inst & mem_mask) == lda_pattern)
 252         disp = -sext<16>(inst & lda_disp_mask);
 253     else if ((inst & intop_mask) == addq_pattern)
 254         disp = -int((inst & intop_disp_mask) >> intop_disp_shift);
 255     else if ((inst & intop_mask) == subq_pattern)
 256         disp = int((inst & intop_disp_mask) >> intop_disp_shift);
 257     else
 258         return false;
 259
 260     return true;
 261 }
 262
 263 bool
 264 StackTrace::decodeSave(MachInst inst, int &reg, int &disp)
 265 {
 266     // lda $stq, disp($sp)
 267     //
 268     // Opcode<31:26> == 0x08
 269     // RA<25:21> == ?
 270     // RB<20:16> == 30
 271     // Disp<15:0>
 272     const MachInst stq_mask = 0xfc1f0000;
 273     const MachInst stq_pattern = 0xb41e0000;
 274     const MachInst stq_disp_mask = 0x0000ffff;
 275     const MachInst reg_mask = 0x03e00000;
 276     const int reg_shift = 21;
 277
 278     if ((inst & stq_mask) == stq_pattern) {
 279         reg = (inst & reg_mask) >> reg_shift;
 280         disp = sext<16>(inst & stq_disp_mask);
 281     } else {
 282         return false;
 283     }
 284
 285     return true;
 286 }
 287
 288 /*
 289  * Decode the function prologue for the function we're in, and note
 290  * which registers are stored where, and how large the stack frame is.
 291  */
 292 bool
 293 StackTrace::decodePrologue(Addr sp, Addr callpc, Addr func,
 294                            int &size, Addr &ra)
 295 {
 296     size = 0;
 297     ra = 0;
 298
 299     for (Addr pc = func; pc < callpc; pc += sizeof(MachInst)) {
 300         MachInst inst;
 301         CopyOut(xc, (uint8_t *)&inst, pc, sizeof(MachInst));
 302
 303         int reg, disp;
 304         if (decodeStack(inst, disp)) {
 305             if (size) {
 306                 // panic("decoding frame size again");
 307                 return true;
 308             }
 309             size += disp;
 310         } else if (decodeSave(inst, reg, disp)) {
 311             if (!ra && reg == ReturnAddressReg) {
 312                 CopyOut(xc, (uint8_t *)&ra, sp + disp, sizeof(Addr));
 313                 if (!ra) {
 314                     // panic("no return address value pc=%#x\n", pc);
 315                     return false;
 316                 }
 317             }
 318         }
 319     }
 320
 321     return true;
 322 }
 323
 324 #if TRACING_ON
 325 void
 326 StackTrace::dump()
 327 {
 328     StringWrap name(xc->getCpuPtr()->name());
 329     SymbolTable *symtab = xc->getSystemPtr()->kernelSymtab;
 330
 331     DPRINTFN("------ Stack ------\n");
 332
 333     string symbol;
 334     for (int i = 0, size = stack.size(); i < size; ++i) {
 335         Addr addr = stack[size - i - 1];
 336         if (addr == user)
 337             symbol = "user";
 338         else if (addr == console)
 339             symbol = "console";
 340         else if (addr == unknown)
 341             symbol = "unknown";
 342         else
 343             symtab->findSymbol(addr, symbol);
 344
 345         DPRINTFN("%#x: %s\n", addr, symbol);
 346     }
 347 }
 348 #endif