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;

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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;
43using namespace AlphaISA;
44
45ProcessInfo::ProcessInfo(ThreadContext *_tc)
46 : tc(_tc)
47{
48 Addr addr = 0;
49
50 VirtualPort *vp;
51
52 vp = tc->getVirtPort();
53
54 if (!tc->getSystemPtr()->kernelSymtab->findAddress("thread_info_size", addr))
55 panic("thread info not compiled into kernel\n");
56 thread_info_size = vp->readGtoH(addr);
57
58 if (!tc->getSystemPtr()->kernelSymtab->findAddress("task_struct_size", addr))
59 panic("thread info not compiled into kernel\n");
60 task_struct_size = vp->readGtoH(addr);
61
62 if (!tc->getSystemPtr()->kernelSymtab->findAddress("thread_info_task", addr))
63 panic("thread info not compiled into kernel\n");
64 task_off = vp->readGtoH(addr);
65
66 if (!tc->getSystemPtr()->kernelSymtab->findAddress("task_struct_pid", addr))
67 panic("thread info not compiled into kernel\n");
68 pid_off = vp->readGtoH(addr);
69
70 if (!tc->getSystemPtr()->kernelSymtab->findAddress("task_struct_comm", addr))
71 panic("thread info not compiled into kernel\n");
72 name_off = vp->readGtoH(addr);
73
74 tc->delVirtPort(vp);
75}
76
77Addr
78ProcessInfo::task(Addr ksp) const
79{
80 Addr base = ksp & ~0x3fff;
81 if (base == ULL(0xfffffc0000000000))
82 return 0;
83
84 Addr tsk;
85
86 VirtualPort *vp;
87
88 vp = tc->getVirtPort();
89 tsk = vp->readGtoH(base + task_off);
90 tc->delVirtPort(vp);
91
92 return tsk;
93}
94
95int
96ProcessInfo::pid(Addr ksp) const
97{
98 Addr task = this->task(ksp);
99 if (!task)
100 return -1;
101
102 uint16_t pd;
103
104 VirtualPort *vp;
105
106 vp = tc->getVirtPort();
107 pd = vp->readGtoH(task + pid_off);
108 tc->delVirtPort(vp);
109
110 return pd;
111}
112
113string
114ProcessInfo::name(Addr ksp) const
115{
116 Addr task = this->task(ksp);
117 if (!task)
118 return "console";
119
120 char comm[256];
121 CopyStringOut(tc, comm, task + name_off, sizeof(comm));
122 if (!comm[0])
123 return "startup";
124
125 return comm;
126}
127
128StackTrace::StackTrace()
129 : tc(0), stack(64)
130{
131}
132
133StackTrace::StackTrace(ThreadContext *_tc, StaticInstPtr inst)
134 : tc(0), stack(64)
135{
136 trace(_tc, inst);
137}
138
139StackTrace::~StackTrace()
140{
141}
142
143void
144StackTrace::trace(ThreadContext *_tc, bool is_call)
145{
146 tc = _tc;
147
148 bool usermode = (tc->readMiscReg(AlphaISA::IPR_DTB_CM) & 0x18) != 0;
149
150 Addr pc = tc->readNextPC();
151 bool kernel = tc->getSystemPtr()->kernelStart <= pc &&
152 pc <= tc->getSystemPtr()->kernelEnd;
153
154 if (usermode) {
155 stack.push_back(user);
156 return;
157 }
158
159 if (!kernel) {
160 stack.push_back(console);
161 return;
162 }
163
164 SymbolTable *symtab = tc->getSystemPtr()->kernelSymtab;
165 Addr ksp = tc->readIntReg(TheISA::StackPointerReg);
166 Addr bottom = ksp & ~0x3fff;
167 Addr addr;
168
169 if (is_call) {
170 if (!symtab->findNearestAddr(pc, addr))
171 panic("could not find address %#x", pc);
172
173 stack.push_back(addr);
174 pc = tc->readPC();
175 }
176
177 Addr ra;
178 int size;
179
180 while (ksp > bottom) {
181 if (!symtab->findNearestAddr(pc, addr))
182 panic("could not find symbol for pc=%#x", pc);
183 assert(pc >= addr && "symbol botch: callpc < func");
184
185 stack.push_back(addr);
186
187 if (isEntry(addr))
188 return;
189
190 if (decodePrologue(ksp, pc, addr, size, ra)) {
191 if (!ra)
192 return;
193
194 if (size <= 0) {
195 stack.push_back(unknown);
196 return;
197 }
198
199 pc = ra;
200 ksp += size;
201 } else {
202 stack.push_back(unknown);
203 return;
204 }
205
206 bool kernel = tc->getSystemPtr()->kernelStart <= pc &&
207 pc <= tc->getSystemPtr()->kernelEnd;
208 if (!kernel)
209 return;
210
211 if (stack.size() >= 1000)
212 panic("unwinding too far");
213 }
214
215 panic("unwinding too far");
216}
217
218bool
219StackTrace::isEntry(Addr addr)
220{
221 if (addr == tc->readMiscReg(AlphaISA::IPR_PALtemp12))
222 return true;
223
224 if (addr == tc->readMiscReg(AlphaISA::IPR_PALtemp7))
225 return true;
226
227 if (addr == tc->readMiscReg(AlphaISA::IPR_PALtemp11))
228 return true;
229
230 if (addr == tc->readMiscReg(AlphaISA::IPR_PALtemp21))
231 return true;
232
233 if (addr == tc->readMiscReg(AlphaISA::IPR_PALtemp9))
234 return true;
235
236 if (addr == tc->readMiscReg(AlphaISA::IPR_PALtemp2))
237 return true;
238
239 return false;
240}
241
242bool
243StackTrace::decodeStack(MachInst inst, int &disp)
244{
245 // lda $sp, -disp($sp)
246 //
247 // Opcode<31:26> == 0x08
248 // RA<25:21> == 30
249 // RB<20:16> == 30
250 // Disp<15:0>
251 const MachInst mem_mask = 0xffff0000;
252 const MachInst lda_pattern = 0x23de0000;
253 const MachInst lda_disp_mask = 0x0000ffff;
254
255 // subq $sp, disp, $sp
256 // addq $sp, disp, $sp
257 //
258 // Opcode<31:26> == 0x10
259 // RA<25:21> == 30
260 // Lit<20:13>
261 // One<12> = 1
262 // Func<11:5> == 0x20 (addq)
263 // Func<11:5> == 0x29 (subq)
264 // RC<4:0> == 30
265 const MachInst intop_mask = 0xffe01fff;
266 const MachInst addq_pattern = 0x43c0141e;
267 const MachInst subq_pattern = 0x43c0153e;
268 const MachInst intop_disp_mask = 0x001fe000;
269 const int intop_disp_shift = 13;
270
271 if ((inst & mem_mask) == lda_pattern)
272 disp = -sext<16>(inst & lda_disp_mask);
273 else if ((inst & intop_mask) == addq_pattern)
274 disp = -int((inst & intop_disp_mask) >> intop_disp_shift);
275 else if ((inst & intop_mask) == subq_pattern)
276 disp = int((inst & intop_disp_mask) >> intop_disp_shift);
277 else
278 return false;
279
280 return true;
281}
282
283bool
284StackTrace::decodeSave(MachInst inst, int &reg, int &disp)
285{
286 // lda $stq, disp($sp)
287 //
288 // Opcode<31:26> == 0x08
289 // RA<25:21> == ?
290 // RB<20:16> == 30
291 // Disp<15:0>
292 const MachInst stq_mask = 0xfc1f0000;
293 const MachInst stq_pattern = 0xb41e0000;
294 const MachInst stq_disp_mask = 0x0000ffff;
295 const MachInst reg_mask = 0x03e00000;
296 const int reg_shift = 21;
297
298 if ((inst & stq_mask) == stq_pattern) {
299 reg = (inst & reg_mask) >> reg_shift;
300 disp = sext<16>(inst & stq_disp_mask);
301 } else {
302 return false;
303 }
304
305 return true;
306}
307
308/*
309 * Decode the function prologue for the function we're in, and note
310 * which registers are stored where, and how large the stack frame is.
311 */
312bool
313StackTrace::decodePrologue(Addr sp, Addr callpc, Addr func,
314 int &size, Addr &ra)
315{
316 size = 0;
317 ra = 0;
318
319 for (Addr pc = func; pc < callpc; pc += sizeof(MachInst)) {
320 MachInst inst;
321 CopyOut(tc, (uint8_t *)&inst, pc, sizeof(MachInst));
322
323 int reg, disp;
324 if (decodeStack(inst, disp)) {
325 if (size) {
326 // panic("decoding frame size again");
327 return true;
328 }
329 size += disp;
330 } else if (decodeSave(inst, reg, disp)) {
331 if (!ra && reg == ReturnAddressReg) {
332 CopyOut(tc, (uint8_t *)&ra, sp + disp, sizeof(Addr));
333 if (!ra) {
334 // panic("no return address value pc=%#x\n", pc);
335 return false;
336 }
337 }
338 }
339 }
340
341 return true;
342}
343
344#if TRACING_ON
345void
346StackTrace::dump()
347{
348 StringWrap name(tc->getCpuPtr()->name());
349 SymbolTable *symtab = tc->getSystemPtr()->kernelSymtab;
350
351 DPRINTFN("------ Stack ------\n");
352
353 string symbol;
354 for (int i = 0, size = stack.size(); i < size; ++i) {
355 Addr addr = stack[size - i - 1];
356 if (addr == user)
357 symbol = "user";
358 else if (addr == console)
359 symbol = "console";
360 else if (addr == unknown)
361 symbol = "unknown";
362 else
363 symtab->findSymbol(addr, symbol);
364
365 DPRINTFN("%#x: %s\n", addr, symbol);
366 }
367}
368#endif