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4daa187d AK |
1 | #!/usr/bin/python |
2 | ||
3 | # GDB debugging support | |
4 | # | |
5 | # Copyright 2012 Red Hat, Inc. and/or its affiliates | |
6 | # | |
7 | # Authors: | |
8 | # Avi Kivity <[email protected]> | |
9 | # | |
10 | # This work is licensed under the terms of the GNU GPL, version 2. See | |
11 | # the COPYING file in the top-level directory. | |
12 | # | |
13 | # Contributions after 2012-01-13 are licensed under the terms of the | |
14 | # GNU GPL, version 2 or (at your option) any later version. | |
15 | ||
16 | ||
17 | import gdb | |
18 | ||
19 | def isnull(ptr): | |
20 | return ptr == gdb.Value(0).cast(ptr.type) | |
21 | ||
22 | def int128(p): | |
23 | return long(p['lo']) + (long(p['hi']) << 64) | |
24 | ||
9eddd6a4 SH |
25 | def get_fs_base(): |
26 | '''Fetch %fs base value using arch_prctl(ARCH_GET_FS)''' | |
27 | # %rsp - 120 is scratch space according to the SystemV ABI | |
28 | old = gdb.parse_and_eval('*(uint64_t*)($rsp - 120)') | |
29 | gdb.execute('call arch_prctl(0x1003, $rsp - 120)', False, True) | |
30 | fs_base = gdb.parse_and_eval('*(uint64_t*)($rsp - 120)') | |
31 | gdb.execute('set *(uint64_t*)($rsp - 120) = %s' % old, False, True) | |
32 | return fs_base | |
33 | ||
34 | def get_glibc_pointer_guard(): | |
35 | '''Fetch glibc pointer guard value''' | |
36 | fs_base = get_fs_base() | |
37 | return gdb.parse_and_eval('*(uint64_t*)((uint64_t)%s + 0x30)' % fs_base) | |
38 | ||
39 | def glibc_ptr_demangle(val, pointer_guard): | |
40 | '''Undo effect of glibc's PTR_MANGLE()''' | |
41 | return gdb.parse_and_eval('(((uint64_t)%s >> 0x11) | ((uint64_t)%s << (64 - 0x11))) ^ (uint64_t)%s' % (val, val, pointer_guard)) | |
42 | ||
43 | def bt_jmpbuf(jmpbuf): | |
44 | '''Backtrace a jmpbuf''' | |
45 | JB_RBX = 0 | |
46 | JB_RBP = 1 | |
47 | JB_R12 = 2 | |
48 | JB_R13 = 3 | |
49 | JB_R14 = 4 | |
50 | JB_R15 = 5 | |
51 | JB_RSP = 6 | |
52 | JB_PC = 7 | |
53 | ||
54 | old_rbx = gdb.parse_and_eval('(uint64_t)$rbx') | |
55 | old_rbp = gdb.parse_and_eval('(uint64_t)$rbp') | |
56 | old_rsp = gdb.parse_and_eval('(uint64_t)$rsp') | |
57 | old_r12 = gdb.parse_and_eval('(uint64_t)$r12') | |
58 | old_r13 = gdb.parse_and_eval('(uint64_t)$r13') | |
59 | old_r14 = gdb.parse_and_eval('(uint64_t)$r14') | |
60 | old_r15 = gdb.parse_and_eval('(uint64_t)$r15') | |
61 | old_rip = gdb.parse_and_eval('(uint64_t)$rip') | |
62 | ||
63 | pointer_guard = get_glibc_pointer_guard() | |
64 | gdb.execute('set $rbx = %s' % jmpbuf[JB_RBX]) | |
65 | gdb.execute('set $rbp = %s' % glibc_ptr_demangle(jmpbuf[JB_RBP], pointer_guard)) | |
66 | gdb.execute('set $rsp = %s' % glibc_ptr_demangle(jmpbuf[JB_RSP], pointer_guard)) | |
67 | gdb.execute('set $r12 = %s' % jmpbuf[JB_R12]) | |
68 | gdb.execute('set $r13 = %s' % jmpbuf[JB_R13]) | |
69 | gdb.execute('set $r14 = %s' % jmpbuf[JB_R14]) | |
70 | gdb.execute('set $r15 = %s' % jmpbuf[JB_R15]) | |
71 | gdb.execute('set $rip = %s' % glibc_ptr_demangle(jmpbuf[JB_PC], pointer_guard)) | |
72 | ||
73 | gdb.execute('bt') | |
74 | ||
75 | gdb.execute('set $rbx = %s' % old_rbx) | |
76 | gdb.execute('set $rbp = %s' % old_rbp) | |
77 | gdb.execute('set $rsp = %s' % old_rsp) | |
78 | gdb.execute('set $r12 = %s' % old_r12) | |
79 | gdb.execute('set $r13 = %s' % old_r13) | |
80 | gdb.execute('set $r14 = %s' % old_r14) | |
81 | gdb.execute('set $r15 = %s' % old_r15) | |
82 | gdb.execute('set $rip = %s' % old_rip) | |
83 | ||
4daa187d AK |
84 | class QemuCommand(gdb.Command): |
85 | '''Prefix for QEMU debug support commands''' | |
86 | def __init__(self): | |
87 | gdb.Command.__init__(self, 'qemu', gdb.COMMAND_DATA, | |
88 | gdb.COMPLETE_NONE, True) | |
89 | ||
9eddd6a4 SH |
90 | class CoroutineCommand(gdb.Command): |
91 | '''Display coroutine backtrace''' | |
92 | def __init__(self): | |
93 | gdb.Command.__init__(self, 'qemu coroutine', gdb.COMMAND_DATA, | |
94 | gdb.COMPLETE_NONE) | |
95 | ||
96 | def invoke(self, arg, from_tty): | |
97 | argv = gdb.string_to_argv(arg) | |
98 | if len(argv) != 1: | |
99 | gdb.write('usage: qemu coroutine <coroutine-pointer>\n') | |
100 | return | |
101 | ||
102 | coroutine_pointer = gdb.parse_and_eval(argv[0]).cast(gdb.lookup_type('CoroutineUContext').pointer()) | |
103 | bt_jmpbuf(coroutine_pointer['env']['__jmpbuf']) | |
104 | ||
4daa187d AK |
105 | class MtreeCommand(gdb.Command): |
106 | '''Display the memory tree hierarchy''' | |
107 | def __init__(self): | |
108 | gdb.Command.__init__(self, 'qemu mtree', gdb.COMMAND_DATA, | |
109 | gdb.COMPLETE_NONE) | |
110 | self.queue = [] | |
111 | def invoke(self, arg, from_tty): | |
112 | self.seen = set() | |
113 | self.queue_root('address_space_memory') | |
114 | self.queue_root('address_space_io') | |
115 | self.process_queue() | |
116 | def queue_root(self, varname): | |
117 | ptr = gdb.parse_and_eval(varname)['root'] | |
118 | self.queue.append(ptr) | |
119 | def process_queue(self): | |
120 | while self.queue: | |
121 | ptr = self.queue.pop(0) | |
122 | if long(ptr) in self.seen: | |
123 | continue | |
124 | self.print_item(ptr) | |
125 | def print_item(self, ptr, offset = gdb.Value(0), level = 0): | |
126 | self.seen.add(long(ptr)) | |
127 | addr = ptr['addr'] | |
128 | addr += offset | |
129 | size = int128(ptr['size']) | |
130 | alias = ptr['alias'] | |
131 | klass = '' | |
132 | if not isnull(alias): | |
133 | klass = ' (alias)' | |
134 | elif not isnull(ptr['ops']): | |
135 | klass = ' (I/O)' | |
136 | elif bool(ptr['ram']): | |
137 | klass = ' (RAM)' | |
138 | gdb.write('%s%016x-%016x %s%s (@ %s)\n' | |
139 | % (' ' * level, | |
140 | long(addr), | |
141 | long(addr + (size - 1)), | |
142 | ptr['name'].string(), | |
143 | klass, | |
144 | ptr, | |
145 | ), | |
146 | gdb.STDOUT) | |
147 | if not isnull(alias): | |
148 | gdb.write('%s alias: %s@%016x (@ %s)\n' % | |
149 | (' ' * level, | |
150 | alias['name'].string(), | |
151 | ptr['alias_offset'], | |
152 | alias, | |
153 | ), | |
154 | gdb.STDOUT) | |
155 | self.queue.append(alias) | |
156 | subregion = ptr['subregions']['tqh_first'] | |
157 | level += 1 | |
158 | while not isnull(subregion): | |
159 | self.print_item(subregion, addr, level) | |
160 | subregion = subregion['subregions_link']['tqe_next'] | |
161 | ||
162 | QemuCommand() | |
9eddd6a4 | 163 | CoroutineCommand() |
4daa187d | 164 | MtreeCommand() |