1 // Copyright (c) 2014, 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 #include "client/linux/dump_writer_common/seccomp_unwinder.h"
31
32 #include <string.h>
33
34 #include "google_breakpad/common/minidump_format.h"
35 #include "common/linux/linux_libc_support.h"
36
37 namespace google_breakpad {
38
PopSeccompStackFrame(RawContextCPU * cpu,const MDRawThread & thread,uint8_t * stack_copy)39 void SeccompUnwinder::PopSeccompStackFrame(RawContextCPU* cpu,
40 const MDRawThread& thread,
41 uint8_t* stack_copy) {
42 #if defined(__x86_64)
43 uint64_t bp = cpu->rbp;
44 uint64_t top = thread.stack.start_of_memory_range;
45 for (int i = 4; i--; ) {
46 if (bp < top ||
47 bp > thread.stack.start_of_memory_range +
48 thread.stack.memory.data_size - sizeof(bp) ||
49 bp & 1) {
50 break;
51 }
52 uint64_t old_top = top;
53 top = bp;
54 uint8_t* bp_addr = stack_copy + bp - thread.stack.start_of_memory_range;
55 my_memcpy(&bp, bp_addr, sizeof(bp));
56 if (bp == 0xDEADBEEFDEADBEEFull) {
57 struct {
58 uint64_t r15;
59 uint64_t r14;
60 uint64_t r13;
61 uint64_t r12;
62 uint64_t r11;
63 uint64_t r10;
64 uint64_t r9;
65 uint64_t r8;
66 uint64_t rdi;
67 uint64_t rsi;
68 uint64_t rdx;
69 uint64_t rcx;
70 uint64_t rbx;
71 uint64_t deadbeef;
72 uint64_t rbp;
73 uint64_t fakeret;
74 uint64_t ret;
75 /* char redzone[128]; */
76 } seccomp_stackframe;
77 if (top - offsetof(__typeof__(seccomp_stackframe), deadbeef) < old_top ||
78 top - offsetof(__typeof__(seccomp_stackframe), deadbeef) +
79 sizeof(seccomp_stackframe) >
80 thread.stack.start_of_memory_range+thread.stack.memory.data_size) {
81 break;
82 }
83 my_memcpy(&seccomp_stackframe,
84 bp_addr - offsetof(__typeof__(seccomp_stackframe), deadbeef),
85 sizeof(seccomp_stackframe));
86 cpu->rbx = seccomp_stackframe.rbx;
87 cpu->rcx = seccomp_stackframe.rcx;
88 cpu->rdx = seccomp_stackframe.rdx;
89 cpu->rsi = seccomp_stackframe.rsi;
90 cpu->rdi = seccomp_stackframe.rdi;
91 cpu->rbp = seccomp_stackframe.rbp;
92 cpu->rsp = top + 4*sizeof(uint64_t) + 128;
93 cpu->r8 = seccomp_stackframe.r8;
94 cpu->r9 = seccomp_stackframe.r9;
95 cpu->r10 = seccomp_stackframe.r10;
96 cpu->r11 = seccomp_stackframe.r11;
97 cpu->r12 = seccomp_stackframe.r12;
98 cpu->r13 = seccomp_stackframe.r13;
99 cpu->r14 = seccomp_stackframe.r14;
100 cpu->r15 = seccomp_stackframe.r15;
101 cpu->rip = seccomp_stackframe.fakeret;
102 return;
103 }
104 }
105 #elif defined(__i386__)
106 uint32_t bp = cpu->ebp;
107 uint32_t top = thread.stack.start_of_memory_range;
108 for (int i = 4; i--; ) {
109 if (bp < top ||
110 bp > thread.stack.start_of_memory_range +
111 thread.stack.memory.data_size - sizeof(bp) ||
112 bp & 1) {
113 break;
114 }
115 uint32_t old_top = top;
116 top = bp;
117 uint8_t* bp_addr = stack_copy + bp - thread.stack.start_of_memory_range;
118 my_memcpy(&bp, bp_addr, sizeof(bp));
119 if (bp == 0xDEADBEEFu) {
120 struct {
121 uint32_t edi;
122 uint32_t esi;
123 uint32_t edx;
124 uint32_t ecx;
125 uint32_t ebx;
126 uint32_t deadbeef;
127 uint32_t ebp;
128 uint32_t fakeret;
129 uint32_t ret;
130 } seccomp_stackframe;
131 if (top - offsetof(__typeof__(seccomp_stackframe), deadbeef) < old_top ||
132 top - offsetof(__typeof__(seccomp_stackframe), deadbeef) +
133 sizeof(seccomp_stackframe) >
134 thread.stack.start_of_memory_range+thread.stack.memory.data_size) {
135 break;
136 }
137 my_memcpy(&seccomp_stackframe,
138 bp_addr - offsetof(__typeof__(seccomp_stackframe), deadbeef),
139 sizeof(seccomp_stackframe));
140 cpu->ebx = seccomp_stackframe.ebx;
141 cpu->ecx = seccomp_stackframe.ecx;
142 cpu->edx = seccomp_stackframe.edx;
143 cpu->esi = seccomp_stackframe.esi;
144 cpu->edi = seccomp_stackframe.edi;
145 cpu->ebp = seccomp_stackframe.ebp;
146 cpu->esp = top + 4*sizeof(void*);
147 cpu->eip = seccomp_stackframe.fakeret;
148 return;
149 }
150 }
151 #endif
152 }
153
154 } // namespace google_breakpad
155