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author | 2016-06-03 03:33:22 +0000 | |
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committer | 2016-06-03 03:33:23 +0000 | |
commit | da27230f80795d0028333713f036d44c53cb0e68 (patch) | |
tree | b3d379eaf000adf72b36cb01cdf4d79c3e3f064c /qemu/scripts/qemugdb/coroutine.py | |
parent | 0e68cb048bb8aadb14675f5d4286d8ab2fc35449 (diff) | |
parent | 437fd90c0250dee670290f9b714253671a990160 (diff) |
Merge "These changes are the raw update to qemu-2.6."
Diffstat (limited to 'qemu/scripts/qemugdb/coroutine.py')
-rw-r--r-- | qemu/scripts/qemugdb/coroutine.py | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/qemu/scripts/qemugdb/coroutine.py b/qemu/scripts/qemugdb/coroutine.py new file mode 100644 index 000000000..ab699794a --- /dev/null +++ b/qemu/scripts/qemugdb/coroutine.py @@ -0,0 +1,119 @@ +#!/usr/bin/python + +# GDB debugging support +# +# Copyright 2012 Red Hat, Inc. and/or its affiliates +# +# Authors: +# Avi Kivity <avi@redhat.com> +# +# This work is licensed under the terms of the GNU GPL, version 2. See +# the COPYING file in the top-level directory. +# +# Contributions after 2012-01-13 are licensed under the terms of the +# GNU GPL, version 2 or (at your option) any later version. + +import gdb + +VOID_PTR = gdb.lookup_type('void').pointer() + +def get_fs_base(): + '''Fetch %fs base value using arch_prctl(ARCH_GET_FS). This is + pthread_self().''' + # %rsp - 120 is scratch space according to the SystemV ABI + old = gdb.parse_and_eval('*(uint64_t*)($rsp - 120)') + gdb.execute('call arch_prctl(0x1003, $rsp - 120)', False, True) + fs_base = gdb.parse_and_eval('*(uint64_t*)($rsp - 120)') + gdb.execute('set *(uint64_t*)($rsp - 120) = %s' % old, False, True) + return fs_base + +def pthread_self(): + '''Fetch pthread_self() from the glibc start_thread function.''' + f = gdb.newest_frame() + while f.name() != 'start_thread': + f = f.older() + if f is None: + return get_fs_base() + + try: + return f.read_var("arg") + except ValueError: + return get_fs_base() + +def get_glibc_pointer_guard(): + '''Fetch glibc pointer guard value''' + fs_base = pthread_self() + return gdb.parse_and_eval('*(uint64_t*)((uint64_t)%s + 0x30)' % fs_base) + +def glibc_ptr_demangle(val, pointer_guard): + '''Undo effect of glibc's PTR_MANGLE()''' + return gdb.parse_and_eval('(((uint64_t)%s >> 0x11) | ((uint64_t)%s << (64 - 0x11))) ^ (uint64_t)%s' % (val, val, pointer_guard)) + +def get_jmpbuf_regs(jmpbuf): + JB_RBX = 0 + JB_RBP = 1 + JB_R12 = 2 + JB_R13 = 3 + JB_R14 = 4 + JB_R15 = 5 + JB_RSP = 6 + JB_PC = 7 + + pointer_guard = get_glibc_pointer_guard() + return {'rbx': jmpbuf[JB_RBX], + 'rbp': glibc_ptr_demangle(jmpbuf[JB_RBP], pointer_guard), + 'rsp': glibc_ptr_demangle(jmpbuf[JB_RSP], pointer_guard), + 'r12': jmpbuf[JB_R12], + 'r13': jmpbuf[JB_R13], + 'r14': jmpbuf[JB_R14], + 'r15': jmpbuf[JB_R15], + 'rip': glibc_ptr_demangle(jmpbuf[JB_PC], pointer_guard) } + +def bt_jmpbuf(jmpbuf): + '''Backtrace a jmpbuf''' + regs = get_jmpbuf_regs(jmpbuf) + old = dict() + + for i in regs: + old[i] = gdb.parse_and_eval('(uint64_t)$%s' % i) + + for i in regs: + gdb.execute('set $%s = %s' % (i, regs[i])) + + gdb.execute('bt') + + for i in regs: + gdb.execute('set $%s = %s' % (i, old[i])) + +def coroutine_to_jmpbuf(co): + coroutine_pointer = co.cast(gdb.lookup_type('CoroutineUContext').pointer()) + return coroutine_pointer['env']['__jmpbuf'] + + +class CoroutineCommand(gdb.Command): + '''Display coroutine backtrace''' + def __init__(self): + gdb.Command.__init__(self, 'qemu coroutine', gdb.COMMAND_DATA, + gdb.COMPLETE_NONE) + + def invoke(self, arg, from_tty): + argv = gdb.string_to_argv(arg) + if len(argv) != 1: + gdb.write('usage: qemu coroutine <coroutine-pointer>\n') + return + + bt_jmpbuf(coroutine_to_jmpbuf(gdb.parse_and_eval(argv[0]))) + +class CoroutineSPFunction(gdb.Function): + def __init__(self): + gdb.Function.__init__(self, 'qemu_coroutine_sp') + + def invoke(self, addr): + return get_jmpbuf_regs(coroutine_to_jmpbuf(addr))['rsp'].cast(VOID_PTR) + +class CoroutinePCFunction(gdb.Function): + def __init__(self): + gdb.Function.__init__(self, 'qemu_coroutine_pc') + + def invoke(self, addr): + return get_jmpbuf_regs(coroutine_to_jmpbuf(addr))['rip'].cast(VOID_PTR) |