1 //===-- StopInfoMachException.cpp -------------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "StopInfoMachException.h"
11 
12 // C Includes
13 // C++ Includes
14 // Other libraries and framework includes
15 // Project includes
16 #include "lldb/Breakpoint/Watchpoint.h"
17 #include "lldb/Core/ArchSpec.h"
18 #include "lldb/Core/StreamString.h"
19 #include "lldb/Symbol/Symbol.h"
20 #include "lldb/Target/DynamicLoader.h"
21 #include "lldb/Target/ExecutionContext.h"
22 #include "lldb/Target/Process.h"
23 #include "lldb/Target/RegisterContext.h"
24 #include "lldb/Target/Target.h"
25 #include "lldb/Target/Thread.h"
26 #include "lldb/Target/ThreadPlan.h"
27 #include "lldb/Target/UnixSignals.h"
28 
29 using namespace lldb;
30 using namespace lldb_private;
31 
32 const char *
33 StopInfoMachException::GetDescription ()
34 {
35     if (m_description.empty() && m_value != 0)
36     {
37         ExecutionContext exe_ctx (m_thread.shared_from_this());
38         Target *target = exe_ctx.GetTargetPtr();
39         const llvm::Triple::ArchType cpu = target ? target->GetArchitecture().GetMachine() : llvm::Triple::UnknownArch;
40 
41         const char *exc_desc = NULL;
42         const char *code_label = "code";
43         const char *code_desc = NULL;
44         const char *subcode_label = "subcode";
45         const char *subcode_desc = NULL;
46         switch (m_value)
47         {
48         case 1: // EXC_BAD_ACCESS
49             exc_desc = "EXC_BAD_ACCESS";
50             subcode_label = "address";
51             switch (cpu)
52             {
53             case llvm::Triple::arm:
54                 switch (m_exc_code)
55                 {
56                 case 0x101: code_desc = "EXC_ARM_DA_ALIGN"; break;
57                 case 0x102: code_desc = "EXC_ARM_DA_DEBUG"; break;
58                 }
59                 break;
60 
61             case llvm::Triple::ppc:
62             case llvm::Triple::ppc64:
63                 switch (m_exc_code)
64                 {
65                 case 0x101: code_desc = "EXC_PPC_VM_PROT_READ"; break;
66                 case 0x102: code_desc = "EXC_PPC_BADSPACE";     break;
67                 case 0x103: code_desc = "EXC_PPC_UNALIGNED";    break;
68                 }
69                 break;
70 
71             default:
72                 break;
73             }
74             break;
75 
76         case 2: // EXC_BAD_INSTRUCTION
77             exc_desc = "EXC_BAD_INSTRUCTION";
78             switch (cpu)
79             {
80             case llvm::Triple::x86:
81             case llvm::Triple::x86_64:
82                 if (m_exc_code == 1)
83                     code_desc = "EXC_I386_INVOP";
84                 break;
85 
86             case llvm::Triple::ppc:
87             case llvm::Triple::ppc64:
88                 switch (m_exc_code)
89                 {
90                 case 1: code_desc = "EXC_PPC_INVALID_SYSCALL"; break;
91                 case 2: code_desc = "EXC_PPC_UNIPL_INST"; break;
92                 case 3: code_desc = "EXC_PPC_PRIVINST"; break;
93                 case 4: code_desc = "EXC_PPC_PRIVREG"; break;
94                 case 5: code_desc = "EXC_PPC_TRACE"; break;
95                 case 6: code_desc = "EXC_PPC_PERFMON"; break;
96                 }
97                 break;
98 
99             case llvm::Triple::arm:
100                 if (m_exc_code == 1)
101                     code_desc = "EXC_ARM_UNDEFINED";
102                 break;
103 
104             default:
105                 break;
106             }
107             break;
108 
109         case 3: // EXC_ARITHMETIC
110             exc_desc = "EXC_ARITHMETIC";
111             switch (cpu)
112             {
113             case llvm::Triple::x86:
114             case llvm::Triple::x86_64:
115                 switch (m_exc_code)
116                 {
117                 case 1: code_desc = "EXC_I386_DIV"; break;
118                 case 2: code_desc = "EXC_I386_INTO"; break;
119                 case 3: code_desc = "EXC_I386_NOEXT"; break;
120                 case 4: code_desc = "EXC_I386_EXTOVR"; break;
121                 case 5: code_desc = "EXC_I386_EXTERR"; break;
122                 case 6: code_desc = "EXC_I386_EMERR"; break;
123                 case 7: code_desc = "EXC_I386_BOUND"; break;
124                 case 8: code_desc = "EXC_I386_SSEEXTERR"; break;
125                 }
126                 break;
127 
128             case llvm::Triple::ppc:
129             case llvm::Triple::ppc64:
130                 switch (m_exc_code)
131                 {
132                 case 1: code_desc = "EXC_PPC_OVERFLOW"; break;
133                 case 2: code_desc = "EXC_PPC_ZERO_DIVIDE"; break;
134                 case 3: code_desc = "EXC_PPC_FLT_INEXACT"; break;
135                 case 4: code_desc = "EXC_PPC_FLT_ZERO_DIVIDE"; break;
136                 case 5: code_desc = "EXC_PPC_FLT_UNDERFLOW"; break;
137                 case 6: code_desc = "EXC_PPC_FLT_OVERFLOW"; break;
138                 case 7: code_desc = "EXC_PPC_FLT_NOT_A_NUMBER"; break;
139                 }
140                 break;
141 
142             default:
143                 break;
144             }
145             break;
146 
147         case 4: // EXC_EMULATION
148             exc_desc = "EXC_EMULATION";
149             break;
150 
151 
152         case 5: // EXC_SOFTWARE
153             exc_desc = "EXC_SOFTWARE";
154             if (m_exc_code == 0x10003)
155             {
156                 subcode_desc = "EXC_SOFT_SIGNAL";
157                 subcode_label = "signo";
158             }
159             break;
160 
161         case 6: // EXC_BREAKPOINT
162             {
163                 exc_desc = "EXC_BREAKPOINT";
164                 switch (cpu)
165                 {
166                 case llvm::Triple::x86:
167                 case llvm::Triple::x86_64:
168                     switch (m_exc_code)
169                     {
170                     case 1: code_desc = "EXC_I386_SGL"; break;
171                     case 2: code_desc = "EXC_I386_BPT"; break;
172                     }
173                     break;
174 
175                 case llvm::Triple::ppc:
176                 case llvm::Triple::ppc64:
177                     switch (m_exc_code)
178                     {
179                     case 1: code_desc = "EXC_PPC_BREAKPOINT"; break;
180                     }
181                     break;
182 
183                 case llvm::Triple::arm:
184                     switch (m_exc_code)
185                     {
186                     case 0x101: code_desc = "EXC_ARM_DA_ALIGN"; break;
187                     case 0x102: code_desc = "EXC_ARM_DA_DEBUG"; break;
188                     case 1: code_desc = "EXC_ARM_BREAKPOINT"; break;
189                     }
190                     break;
191 
192                 default:
193                     break;
194                 }
195             }
196             break;
197 
198         case 7:
199             exc_desc = "EXC_SYSCALL";
200             break;
201 
202         case 8:
203             exc_desc = "EXC_MACH_SYSCALL";
204             break;
205 
206         case 9:
207             exc_desc = "EXC_RPC_ALERT";
208             break;
209 
210         case 10:
211             exc_desc = "EXC_CRASH";
212             break;
213         case 11:
214             exc_desc = "EXC_RESOURCE";
215             break;
216         case 12:
217             exc_desc = "EXC_GUARD";
218             break;
219         }
220 
221         StreamString strm;
222 
223         if (exc_desc)
224             strm.PutCString(exc_desc);
225         else
226             strm.Printf("EXC_??? (%" PRIu64 ")", m_value);
227 
228         if (m_exc_data_count >= 1)
229         {
230             if (code_desc)
231                 strm.Printf(" (%s=%s", code_label, code_desc);
232             else
233                 strm.Printf(" (%s=%" PRIu64, code_label, m_exc_code);
234         }
235 
236         if (m_exc_data_count >= 2)
237         {
238             if (subcode_desc)
239                 strm.Printf(", %s=%s", subcode_label, subcode_desc);
240             else
241                 strm.Printf(", %s=0x%" PRIx64, subcode_label, m_exc_subcode);
242         }
243 
244         if (m_exc_data_count > 0)
245             strm.PutChar(')');
246 
247         m_description.swap (strm.GetString());
248     }
249     return m_description.c_str();
250 }
251 
252 
253 
254 
255 
256 StopInfoSP
257 StopInfoMachException::CreateStopReasonWithMachException
258 (
259     Thread &thread,
260     uint32_t exc_type,
261     uint32_t exc_data_count,
262     uint64_t exc_code,
263     uint64_t exc_sub_code,
264     uint64_t exc_sub_sub_code,
265     bool pc_already_adjusted,
266     bool adjust_pc_if_needed
267 )
268 {
269     if (exc_type != 0)
270     {
271         uint32_t pc_decrement = 0;
272         ExecutionContext exe_ctx (thread.shared_from_this());
273         Target *target = exe_ctx.GetTargetPtr();
274         const llvm::Triple::ArchType cpu = target ? target->GetArchitecture().GetMachine() : llvm::Triple::UnknownArch;
275 
276         switch (exc_type)
277         {
278         case 1: // EXC_BAD_ACCESS
279             break;
280 
281         case 2: // EXC_BAD_INSTRUCTION
282             switch (cpu)
283             {
284             case llvm::Triple::ppc:
285             case llvm::Triple::ppc64:
286                 switch (exc_code)
287                 {
288                 case 1: // EXC_PPC_INVALID_SYSCALL
289                 case 2: // EXC_PPC_UNIPL_INST
290                 case 3: // EXC_PPC_PRIVINST
291                 case 4: // EXC_PPC_PRIVREG
292                     break;
293                 case 5: // EXC_PPC_TRACE
294                     return StopInfo::CreateStopReasonToTrace (thread);
295                 case 6: // EXC_PPC_PERFMON
296                     break;
297                 }
298                 break;
299 
300             default:
301                 break;
302             }
303             break;
304 
305         case 3: // EXC_ARITHMETIC
306         case 4: // EXC_EMULATION
307             break;
308 
309         case 5: // EXC_SOFTWARE
310             if (exc_code == 0x10003) // EXC_SOFT_SIGNAL
311             {
312                 if (exc_sub_code == 5)
313                 {
314                     // On MacOSX, a SIGTRAP can signify that a process has called
315                     // exec, so we should check with our dynamic loader to verify.
316                     ProcessSP process_sp (thread.GetProcess());
317                     if (process_sp)
318                     {
319                         DynamicLoader *dynamic_loader = process_sp->GetDynamicLoader();
320                         if (dynamic_loader && dynamic_loader->ProcessDidExec())
321                         {
322                             // The program was re-exec'ed
323                             return StopInfo::CreateStopReasonWithExec (thread);
324                         }
325 //                        if (!process_did_exec)
326 //                        {
327 //                            // We have a SIGTRAP, make sure we didn't exec by checking
328 //                            // for the PC being at "_dyld_start"...
329 //                            lldb::StackFrameSP frame_sp (thread.GetStackFrameAtIndex(0));
330 //                            if (frame_sp)
331 //                            {
332 //                                const Symbol *symbol = frame_sp->GetSymbolContext(eSymbolContextSymbol).symbol;
333 //                                if (symbol)
334 //                                {
335 //                                    if (symbol->GetName() == ConstString("_dyld_start"))
336 //                                        process_did_exec = true;
337 //                                }
338 //                            }
339 //                        }
340                     }
341                 }
342                 return StopInfo::CreateStopReasonWithSignal (thread, exc_sub_code);
343             }
344             break;
345 
346         case 6: // EXC_BREAKPOINT
347             {
348                 bool is_software_breakpoint = false;
349                 bool is_trace_if_software_breakpoint_missing = false;
350                 switch (cpu)
351                 {
352                 case llvm::Triple::x86:
353                 case llvm::Triple::x86_64:
354                     if (exc_code == 1) // EXC_I386_SGL
355                     {
356                         if (!exc_sub_code)
357                             return StopInfo::CreateStopReasonToTrace(thread);
358 
359                         // It's a watchpoint, then.
360                         // The exc_sub_code indicates the data break address.
361                         lldb::WatchpointSP wp_sp;
362                         if (target)
363                             wp_sp = target->GetWatchpointList().FindByAddress((lldb::addr_t)exc_sub_code);
364                         if (wp_sp && wp_sp->IsEnabled())
365                         {
366                             // Debugserver may piggyback the hardware index of the fired watchpoint in the exception data.
367                             // Set the hardware index if that's the case.
368                             if (exc_data_count >=3)
369                                 wp_sp->SetHardwareIndex((uint32_t)exc_sub_sub_code);
370                             return StopInfo::CreateStopReasonWithWatchpointID(thread, wp_sp->GetID());
371                         }
372                     }
373                     else if (exc_code == 2 ||   // EXC_I386_BPT
374                              exc_code == 3)     // EXC_I386_BPTFLT
375                     {
376                         // KDP returns EXC_I386_BPTFLT for trace breakpoints
377                         if (exc_code == 3)
378                             is_trace_if_software_breakpoint_missing = true;
379 
380                         is_software_breakpoint = true;
381                         if (!pc_already_adjusted)
382                             pc_decrement = 1;
383                     }
384                     break;
385 
386                 case llvm::Triple::ppc:
387                 case llvm::Triple::ppc64:
388                     is_software_breakpoint = exc_code == 1; // EXC_PPC_BREAKPOINT
389                     break;
390 
391                 case llvm::Triple::arm:
392                     if (exc_code == 0x102) // EXC_ARM_DA_DEBUG
393                     {
394                         // It's a watchpoint, then, if the exc_sub_code indicates a known/enabled
395                         // data break address from our watchpoint list.
396                         lldb::WatchpointSP wp_sp;
397                         if (target)
398                             wp_sp = target->GetWatchpointList().FindByAddress((lldb::addr_t)exc_sub_code);
399                         if (wp_sp && wp_sp->IsEnabled())
400                         {
401                             // Debugserver may piggyback the hardware index of the fired watchpoint in the exception data.
402                             // Set the hardware index if that's the case.
403                             if (exc_data_count >=3)
404                                 wp_sp->SetHardwareIndex((uint32_t)exc_sub_sub_code);
405                             return StopInfo::CreateStopReasonWithWatchpointID(thread, wp_sp->GetID());
406                         }
407                         // EXC_ARM_DA_DEBUG seems to be reused for EXC_BREAKPOINT as well as EXC_BAD_ACCESS
408                         if (thread.GetTemporaryResumeState() == eStateStepping)
409                             return StopInfo::CreateStopReasonToTrace(thread);
410                     }
411                     else if (exc_code == 1) // EXC_ARM_BREAKPOINT
412                     {
413                         is_software_breakpoint = true;
414                         is_trace_if_software_breakpoint_missing = true;
415                     }
416                     break;
417 
418                 default:
419                     break;
420                 }
421 
422                 if (is_software_breakpoint)
423                 {
424                     RegisterContextSP reg_ctx_sp (thread.GetRegisterContext());
425                     addr_t pc = reg_ctx_sp->GetPC() - pc_decrement;
426 
427                     ProcessSP process_sp (thread.CalculateProcess());
428 
429                     lldb::BreakpointSiteSP bp_site_sp;
430                     if (process_sp)
431                         bp_site_sp = process_sp->GetBreakpointSiteList().FindByAddress(pc);
432                     if (bp_site_sp && bp_site_sp->IsEnabled())
433                     {
434                         // Update the PC if we were asked to do so, but only do
435                         // so if we find a breakpoint that we know about cause
436                         // this could be a trap instruction in the code
437                         if (pc_decrement > 0 && adjust_pc_if_needed)
438                             reg_ctx_sp->SetPC (pc);
439 
440                         // If the breakpoint is for this thread, then we'll report the hit, but if it is for another thread,
441                         // we can just report no reason.  We don't need to worry about stepping over the breakpoint here, that
442                         // will be taken care of when the thread resumes and notices that there's a breakpoint under the pc.
443                         if (bp_site_sp->ValidForThisThread (&thread))
444                             return StopInfo::CreateStopReasonWithBreakpointSiteID (thread, bp_site_sp->GetID());
445                         else
446                             return StopInfoSP();
447                     }
448 
449                     // Don't call this a trace if we weren't single stepping this thread.
450                     if (is_trace_if_software_breakpoint_missing && thread.GetTemporaryResumeState() == eStateStepping)
451                     {
452                         return StopInfo::CreateStopReasonToTrace (thread);
453                     }
454                 }
455             }
456             break;
457 
458         case 7:     // EXC_SYSCALL
459         case 8:     // EXC_MACH_SYSCALL
460         case 9:     // EXC_RPC_ALERT
461         case 10:    // EXC_CRASH
462             break;
463         }
464 
465         return StopInfoSP(new StopInfoMachException (thread, exc_type, exc_data_count, exc_code, exc_sub_code));
466     }
467     return StopInfoSP();
468 }
469