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