diff options
Diffstat (limited to 'scripts/qemugdb')
| -rw-r--r-- | scripts/qemugdb/aio.py | 58 | ||||
| -rw-r--r-- | scripts/qemugdb/coroutine.py | 90 |
2 files changed, 117 insertions, 31 deletions
diff --git a/scripts/qemugdb/aio.py b/scripts/qemugdb/aio.py new file mode 100644 index 0000000000..2ba00c4444 --- /dev/null +++ b/scripts/qemugdb/aio.py @@ -0,0 +1,58 @@ +#!/usr/bin/python + +# GDB debugging support: aio/iohandler debug +# +# Copyright (c) 2015 Red Hat, Inc. +# +# Author: Dr. David Alan Gilbert <dgilbert@redhat.com> +# +# This work is licensed under the terms of the GNU GPL, version 2 or +# later. See the COPYING file in the top-level directory. +# + +import gdb +from qemugdb import coroutine + +def isnull(ptr): + return ptr == gdb.Value(0).cast(ptr.type) + +def dump_aiocontext(context, verbose): + '''Display a dump and backtrace for an aiocontext''' + cur = context['aio_handlers']['lh_first'] + # Get pointers to functions we're going to process specially + sym_fd_coroutine_enter = gdb.parse_and_eval('fd_coroutine_enter') + + while not isnull(cur): + entry = cur.dereference() + gdb.write('----\n%s\n' % entry) + if verbose and cur['io_read'] == sym_fd_coroutine_enter: + coptr = (cur['opaque'].cast(gdb.lookup_type('FDYieldUntilData').pointer()))['co'] + coptr = coptr.cast(gdb.lookup_type('CoroutineUContext').pointer()) + coroutine.bt_jmpbuf(coptr['env']['__jmpbuf']) + cur = cur['node']['le_next']; + + gdb.write('----\n') + +class HandlersCommand(gdb.Command): + '''Display aio handlers''' + def __init__(self): + gdb.Command.__init__(self, 'qemu handlers', gdb.COMMAND_DATA, + gdb.COMPLETE_NONE) + + def invoke(self, arg, from_tty): + verbose = False + argv = gdb.string_to_argv(arg) + + if len(argv) > 0 and argv[0] == '--verbose': + verbose = True + argv.pop(0) + + if len(argv) > 1: + gdb.write('usage: qemu handlers [--verbose] [handler]\n') + return + + if len(argv) == 1: + handlers_name = argv[0] + else: + handlers_name = 'qemu_aio_context' + dump_aiocontext(gdb.parse_and_eval(handlers_name), verbose) diff --git a/scripts/qemugdb/coroutine.py b/scripts/qemugdb/coroutine.py index 3c54918b5d..ab699794ab 100644 --- a/scripts/qemugdb/coroutine.py +++ b/scripts/qemugdb/coroutine.py @@ -15,8 +15,11 @@ import gdb +VOID_PTR = gdb.lookup_type('void').pointer() + def get_fs_base(): - '''Fetch %fs base value using arch_prctl(ARCH_GET_FS)''' + '''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, $rsp - 120)', False, True) @@ -24,17 +27,29 @@ def get_fs_base(): gdb.execute('set *(uint64_t*)($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 = get_fs_base() + 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 bt_jmpbuf(jmpbuf): - '''Backtrace a jmpbuf''' +def get_jmpbuf_regs(jmpbuf): JB_RBX = 0 JB_RBP = 1 JB_R12 = 2 @@ -44,35 +59,35 @@ def bt_jmpbuf(jmpbuf): JB_RSP = 6 JB_PC = 7 - old_rbx = gdb.parse_and_eval('(uint64_t)$rbx') - old_rbp = gdb.parse_and_eval('(uint64_t)$rbp') - old_rsp = gdb.parse_and_eval('(uint64_t)$rsp') - old_r12 = gdb.parse_and_eval('(uint64_t)$r12') - old_r13 = gdb.parse_and_eval('(uint64_t)$r13') - old_r14 = gdb.parse_and_eval('(uint64_t)$r14') - old_r15 = gdb.parse_and_eval('(uint64_t)$r15') - old_rip = gdb.parse_and_eval('(uint64_t)$rip') - pointer_guard = get_glibc_pointer_guard() - gdb.execute('set $rbx = %s' % jmpbuf[JB_RBX]) - gdb.execute('set $rbp = %s' % glibc_ptr_demangle(jmpbuf[JB_RBP], pointer_guard)) - gdb.execute('set $rsp = %s' % glibc_ptr_demangle(jmpbuf[JB_RSP], pointer_guard)) - gdb.execute('set $r12 = %s' % jmpbuf[JB_R12]) - gdb.execute('set $r13 = %s' % jmpbuf[JB_R13]) - gdb.execute('set $r14 = %s' % jmpbuf[JB_R14]) - gdb.execute('set $r15 = %s' % jmpbuf[JB_R15]) - gdb.execute('set $rip = %s' % glibc_ptr_demangle(jmpbuf[JB_PC], pointer_guard)) + return {'rbx': jmpbuf[JB_RBX], + 'rbp': glibc_ptr_demangle(jmpbuf[JB_RBP], pointer_guard), + 'rsp': glibc_ptr_demangle(jmpbuf[JB_RSP], pointer_guard), + 'r12': jmpbuf[JB_R12], + 'r13': jmpbuf[JB_R13], + 'r14': jmpbuf[JB_R14], + 'r15': jmpbuf[JB_R15], + 'rip': glibc_ptr_demangle(jmpbuf[JB_PC], pointer_guard) } + +def bt_jmpbuf(jmpbuf): + '''Backtrace a jmpbuf''' + regs = get_jmpbuf_regs(jmpbuf) + old = dict() + + for i in regs: + old[i] = gdb.parse_and_eval('(uint64_t)$%s' % i) + + for i in regs: + gdb.execute('set $%s = %s' % (i, regs[i])) gdb.execute('bt') - gdb.execute('set $rbx = %s' % old_rbx) - gdb.execute('set $rbp = %s' % old_rbp) - gdb.execute('set $rsp = %s' % old_rsp) - gdb.execute('set $r12 = %s' % old_r12) - gdb.execute('set $r13 = %s' % old_r13) - gdb.execute('set $r14 = %s' % old_r14) - gdb.execute('set $r15 = %s' % old_r15) - gdb.execute('set $rip = %s' % old_rip) + 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): @@ -87,5 +102,18 @@ class CoroutineCommand(gdb.Command): gdb.write('usage: qemu coroutine <coroutine-pointer>\n') return - coroutine_pointer = gdb.parse_and_eval(argv[0]).cast(gdb.lookup_type('CoroutineUContext').pointer()) - bt_jmpbuf(coroutine_pointer['env']['__jmpbuf']) + 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) |