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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20 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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24 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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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_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
StackwalkerSPARC(const SystemInfo * system_info,const MDRawContextSPARC * context,MemoryRegion * memory,const CodeModules * modules,StackFrameSymbolizer * resolver_helper)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
GetContextFrame()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
GetCallerFrame(const CallStack * stack,bool stack_scan_allowed)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