1 | // Copyright (c) 2010 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 |
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28 | // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
29 | |
30 | // stackwalker_sparc.cc: sparc-specific stackwalker. |
31 | // |
32 | // See stackwalker_sparc.h for documentation. |
33 | // |
34 | // Author: Michael Shang |
35 | |
36 | |
37 | #include "google_breakpad/processor/call_stack.h" |
38 | #include "google_breakpad/processor/memory_region.h" |
39 | #include "google_breakpad/processor/stack_frame_cpu.h" |
40 | #include "processor/logging.h" |
41 | #include "processor/stackwalker_sparc.h" |
42 | |
43 | namespace google_breakpad { |
44 | |
45 | |
46 | StackwalkerSPARC::StackwalkerSPARC(const SystemInfo* system_info, |
47 | const MDRawContextSPARC* context, |
48 | MemoryRegion* memory, |
49 | const CodeModules* modules, |
50 | StackFrameSymbolizer* resolver_helper) |
51 | : Stackwalker(system_info, memory, modules, resolver_helper), |
52 | context_(context) { |
53 | } |
54 | |
55 | |
56 | StackFrame* StackwalkerSPARC::GetContextFrame() { |
57 | if (!context_) { |
58 | BPLOG(ERROR) << "Can't get context frame without context" ; |
59 | return NULL; |
60 | } |
61 | |
62 | StackFrameSPARC* frame = new StackFrameSPARC(); |
63 | |
64 | // The instruction pointer is stored directly in a register, so pull it |
65 | // straight out of the CPU context structure. |
66 | frame->context = *context_; |
67 | frame->context_validity = StackFrameSPARC::CONTEXT_VALID_ALL; |
68 | frame->trust = StackFrame::FRAME_TRUST_CONTEXT; |
69 | frame->instruction = frame->context.pc; |
70 | |
71 | return frame; |
72 | } |
73 | |
74 | |
75 | StackFrame* StackwalkerSPARC::GetCallerFrame(const CallStack* stack, |
76 | bool stack_scan_allowed) { |
77 | if (!memory_ || !stack) { |
78 | BPLOG(ERROR) << "Can't get caller frame without memory or stack" ; |
79 | return NULL; |
80 | } |
81 | |
82 | StackFrameSPARC* last_frame = static_cast<StackFrameSPARC*>( |
83 | stack->frames()->back()); |
84 | |
85 | // new: caller |
86 | // old: callee |
87 | // %fp, %i6 and g_r[30] is the same, see minidump_format.h |
88 | // %sp, %o6 and g_r[14] is the same, see minidump_format.h |
89 | // %sp_new = %fp_old |
90 | // %fp_new = *(%fp_old + 32 + 32 - 8), where the callee's %i6 |
91 | // %pc_new = *(%fp_old + 32 + 32 - 4) + 8 |
92 | // which is callee's %i7 plus 8 |
93 | |
94 | // A caller frame must reside higher in memory than its callee frames. |
95 | // Anything else is an error, or an indication that we've reached the |
96 | // end of the stack. |
97 | uint64_t stack_pointer = last_frame->context.g_r[30]; |
98 | if (stack_pointer <= last_frame->context.g_r[14]) { |
99 | return NULL; |
100 | } |
101 | |
102 | uint32_t instruction; |
103 | if (!memory_->GetMemoryAtAddress(stack_pointer + 60, |
104 | &instruction) || instruction <= 1) { |
105 | return NULL; |
106 | } |
107 | |
108 | uint32_t stack_base; |
109 | if (!memory_->GetMemoryAtAddress(stack_pointer + 56, |
110 | &stack_base) || stack_base <= 1) { |
111 | return NULL; |
112 | } |
113 | |
114 | // Should we terminate the stack walk? (end-of-stack or broken invariant) |
115 | if (TerminateWalk(instruction, |
116 | stack_pointer, |
117 | last_frame->context.g_r[14], |
118 | stack->frames()->size() == 1)) { |
119 | return NULL; |
120 | } |
121 | |
122 | StackFrameSPARC* frame = new StackFrameSPARC(); |
123 | |
124 | frame->context = last_frame->context; |
125 | frame->context.g_r[14] = stack_pointer; |
126 | frame->context.g_r[30] = stack_base; |
127 | |
128 | // frame->context.pc is the return address, which is 2 instruction |
129 | // past the branch that caused us to arrive at the callee, which are |
130 | // a CALL instruction then a NOP instruction. |
131 | // frame_ppc->instruction to 8 less than that. Since all sparc |
132 | // instructions are 4 bytes wide, this is the address of the branch |
133 | // instruction. This allows source line information to match up with the |
134 | // line that contains a function call. Callers that require the exact |
135 | // return address value may access the %i7/g_r[31] field of StackFrameSPARC. |
136 | frame->context.pc = instruction + 8; |
137 | frame->instruction = instruction; |
138 | frame->context_validity = StackFrameSPARC::CONTEXT_VALID_PC | |
139 | StackFrameSPARC::CONTEXT_VALID_SP | |
140 | StackFrameSPARC::CONTEXT_VALID_FP; |
141 | frame->trust = StackFrame::FRAME_TRUST_FP; |
142 | |
143 | return frame; |
144 | } |
145 | |
146 | |
147 | } // namespace google_breakpad |
148 | |