3 # GDB debugging support
5 # Copyright 2012 Red Hat, Inc. and/or its affiliates
8 # Avi Kivity <avi@redhat.com>
10 # This work is licensed under the terms of the GNU GPL, version 2
11 # or later. See the COPYING file in the top-level directory.
15 VOID_PTR
= gdb
.lookup_type('void').pointer()
18 '''Fetch %fs base value using arch_prctl(ARCH_GET_FS). This is
20 # %rsp - 120 is scratch space according to the SystemV ABI
21 old
= gdb
.parse_and_eval('*(uint64_t*)($rsp - 120)')
22 gdb
.execute('call (int)arch_prctl(0x1003, $rsp - 120)', False, True)
23 fs_base
= gdb
.parse_and_eval('*(uint64_t*)($rsp - 120)')
24 gdb
.execute('set *(uint64_t*)($rsp - 120) = %s' % old
, False, True)
28 '''Fetch pthread_self() from the glibc start_thread function.'''
29 f
= gdb
.newest_frame()
30 while f
.name() != 'start_thread':
36 return f
.read_var("arg")
40 def get_glibc_pointer_guard():
41 '''Fetch glibc pointer guard value'''
42 fs_base
= pthread_self()
43 return gdb
.parse_and_eval('*(uint64_t*)((uint64_t)%s + 0x30)' % fs_base
)
45 def glibc_ptr_demangle(val
, pointer_guard
):
46 '''Undo effect of glibc's PTR_MANGLE()'''
47 return gdb
.parse_and_eval('(((uint64_t)%s >> 0x11) | ((uint64_t)%s << (64 - 0x11))) ^ (uint64_t)%s' % (val
, val
, pointer_guard
))
49 def get_jmpbuf_regs(jmpbuf
):
59 pointer_guard
= get_glibc_pointer_guard()
60 return {'rbx': jmpbuf
[JB_RBX
],
61 'rbp': glibc_ptr_demangle(jmpbuf
[JB_RBP
], pointer_guard
),
62 'rsp': glibc_ptr_demangle(jmpbuf
[JB_RSP
], pointer_guard
),
63 'r12': jmpbuf
[JB_R12
],
64 'r13': jmpbuf
[JB_R13
],
65 'r14': jmpbuf
[JB_R14
],
66 'r15': jmpbuf
[JB_R15
],
67 'rip': glibc_ptr_demangle(jmpbuf
[JB_PC
], pointer_guard
) }
69 def bt_jmpbuf(jmpbuf
):
70 '''Backtrace a jmpbuf'''
71 regs
= get_jmpbuf_regs(jmpbuf
)
75 old
[i
] = gdb
.parse_and_eval('(uint64_t)$%s' % i
)
78 gdb
.execute('set $%s = %s' % (i
, regs
[i
]))
83 gdb
.execute('set $%s = %s' % (i
, old
[i
]))
85 def coroutine_to_jmpbuf(co
):
86 coroutine_pointer
= co
.cast(gdb
.lookup_type('CoroutineUContext').pointer())
87 return coroutine_pointer
['env']['__jmpbuf']
90 class CoroutineCommand(gdb
.Command
):
91 '''Display coroutine backtrace'''
93 gdb
.Command
.__init
__(self
, 'qemu coroutine', gdb
.COMMAND_DATA
,
96 def invoke(self
, arg
, from_tty
):
97 argv
= gdb
.string_to_argv(arg
)
99 gdb
.write('usage: qemu coroutine <coroutine-pointer>\n')
102 bt_jmpbuf(coroutine_to_jmpbuf(gdb
.parse_and_eval(argv
[0])))
104 class CoroutineSPFunction(gdb
.Function
):
106 gdb
.Function
.__init
__(self
, 'qemu_coroutine_sp')
108 def invoke(self
, addr
):
109 return get_jmpbuf_regs(coroutine_to_jmpbuf(addr
))['rsp'].cast(VOID_PTR
)
111 class CoroutinePCFunction(gdb
.Function
):
113 gdb
.Function
.__init
__(self
, 'qemu_coroutine_pc')
115 def invoke(self
, addr
):
116 return get_jmpbuf_regs(coroutine_to_jmpbuf(addr
))['rip'].cast(VOID_PTR
)