1 // Copyright (c) 2007, Google Inc.
2 // All rights reserved.
3 //
4 // Redistribution and use in source and binary forms, with or without
5 // modification, are permitted provided that the following conditions are
6 // met:
7 //
8 // * Redistributions of source code must retain the above copyright
9 // notice, this list of conditions and the following disclaimer.
10 // * Redistributions in binary form must reproduce the above
11 // copyright notice, this list of conditions and the following disclaimer
12 // in the documentation and/or other materials provided with the
13 // distribution.
14 // * Neither the name of Google Inc. nor the names of its
15 // contributors may be used to endorse or promote products derived from
16 // this software without specific prior written permission.
17 //
18 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29
30 // stackwalker_amd64.cc: amd64-specific stackwalker.
31 //
32 // See stackwalker_amd64.h for documentation.
33 //
34 // Author: Mark Mentovai, Ted Mielczarek
35
36
37 #include "processor/stackwalker_amd64.h"
38 #include "google_breakpad/processor/call_stack.h"
39 #include "google_breakpad/processor/memory_region.h"
40 #include "google_breakpad/processor/stack_frame_cpu.h"
41 #include "processor/logging.h"
42
43 namespace google_breakpad {
44
45
StackwalkerAMD64(const SystemInfo * system_info,const MDRawContextAMD64 * context,MemoryRegion * memory,const CodeModules * modules,SymbolSupplier * supplier,SourceLineResolverInterface * resolver)46 StackwalkerAMD64::StackwalkerAMD64(const SystemInfo *system_info,
47 const MDRawContextAMD64 *context,
48 MemoryRegion *memory,
49 const CodeModules *modules,
50 SymbolSupplier *supplier,
51 SourceLineResolverInterface *resolver)
52 : Stackwalker(system_info, memory, modules, supplier, resolver),
53 context_(context) {
54 }
55
56
GetContextFrame()57 StackFrame* StackwalkerAMD64::GetContextFrame() {
58 if (!context_ || !memory_) {
59 BPLOG(ERROR) << "Can't get context frame without context or memory";
60 return NULL;
61 }
62
63 StackFrameAMD64 *frame = new StackFrameAMD64();
64
65 // The instruction pointer is stored directly in a register, so pull it
66 // straight out of the CPU context structure.
67 frame->context = *context_;
68 frame->context_validity = StackFrameAMD64::CONTEXT_VALID_ALL;
69 frame->instruction = frame->context.rip;
70
71 return frame;
72 }
73
74
GetCallerFrame(const CallStack * stack,const vector<linked_ptr<StackFrameInfo>> & stack_frame_info)75 StackFrame* StackwalkerAMD64::GetCallerFrame(
76 const CallStack *stack,
77 const vector< linked_ptr<StackFrameInfo> > &stack_frame_info) {
78 if (!memory_ || !stack) {
79 BPLOG(ERROR) << "Can't get caller frame without memory or stack";
80 return NULL;
81 }
82
83 StackFrameAMD64 *last_frame = static_cast<StackFrameAMD64*>(
84 stack->frames()->back());
85
86 //FIXME: this pretty much doesn't work at all due to FPO
87 // being enabled by default.
88 // Brain-dead stackwalking:
89 // %rip_new = *(%rbp_old + 8)
90 // %rsp_new = %rbp_old + 16
91 // %rbp_new = *(%rbp_old)
92
93 // A caller frame must reside higher in memory than its callee frames.
94 // Anything else is an error, or an indication that we've reached the
95 // end of the stack.
96 u_int64_t stack_pointer = last_frame->context.rbp + 16;
97 if (stack_pointer <= last_frame->context.rsp) {
98 return NULL;
99 }
100
101 u_int64_t instruction;
102 if (!memory_->GetMemoryAtAddress(last_frame->context.rbp + 8,
103 &instruction) ||
104 instruction <= 1) {
105 return NULL;
106 }
107
108 u_int64_t stack_base;
109 if (!memory_->GetMemoryAtAddress(last_frame->context.rbp,
110 &stack_base) ||
111 stack_base <= 1) {
112 return NULL;
113 }
114
115 StackFrameAMD64 *frame = new StackFrameAMD64();
116
117 frame->context = last_frame->context;
118 frame->context.rip = instruction;
119 frame->context.rsp = stack_pointer;
120 frame->context.rbp = stack_base;
121 frame->context_validity = StackFrameAMD64::CONTEXT_VALID_RIP |
122 StackFrameAMD64::CONTEXT_VALID_RSP |
123 StackFrameAMD64::CONTEXT_VALID_RBP;
124
125 frame->instruction = frame->context.rip - 1;
126
127 return frame;
128 }
129
130
131 } // namespace google_breakpad
132