Commit fb270611 authored by Luuk van Dijk's avatar Luuk van Dijk

pkg/runtime: 2 sanity checks in the runtime-gdb.py prettyprinters.

Don't try to print obviously corrupt slices or interfaces.
Doesn't actually solve 3047 or 2818, but seems a good idea anyway.

R=rsc, bsiegert
CC=golang-dev
https://golang.org/cl/5708061
parent ecdd9f23
......@@ -5,7 +5,7 @@
"""GDB Pretty printers and convenience functions for Go's runtime structures.
This script is loaded by GDB when it finds a .debug_gdb_scripts
section in the compiled binary. The [68]l linkers emit this with a
section in the compiled binary. The [68]l linkers emit this with a
path to this file based on the path to the runtime package.
"""
......@@ -58,6 +58,8 @@ class SliceTypePrinter:
return str(self.val.type)[6:] # skip 'struct '
def children(self):
if self.val["len"] > self.val["cap"]:
return
ptr = self.val["array"]
for idx in range(self.val["len"]):
yield ('[%d]' % idx, (ptr + idx).dereference())
......@@ -85,7 +87,7 @@ class MapTypePrinter:
stab = self.val['st']
i = 0
for v in self.traverse_hash(stab):
yield ("[%d]" % i, v['key'])
yield ("[%d]" % i, v['key'])
yield ("[%d]" % (i + 1), v['val'])
i += 2
......@@ -122,10 +124,10 @@ class ChanTypePrinter:
return str(self.val.type)
def children(self):
# see chan.c chanbuf(). et is the type stolen from hchan<T>::recvq->first->elem
# see chan.c chanbuf(). et is the type stolen from hchan<T>::recvq->first->elem
et = [x.type for x in self.val['recvq']['first'].type.target().fields() if x.name == 'elem'][0]
ptr = (self.val.address + 1).cast(et.pointer())
for i in range(self.val["qcount"]):
ptr = (self.val.address + 1).cast(et.pointer())
for i in range(self.val["qcount"]):
j = (self.val["recvx"] + i) % self.val["dataqsiz"]
yield ('[%d]' % i, (ptr + j).dereference())
......@@ -184,12 +186,10 @@ def lookup_type(name):
except:
pass
_rctp_type = gdb.lookup_type("struct runtime.commonType").pointer()
_rtp_type = gdb.lookup_type("struct runtime._type").pointer()
def iface_dtype(obj):
"Decode type of the data field of an eface or iface struct."
# known issue: dtype_name decoded from runtime.commonType is "nested.Foo"
# but the dwarf table lists it as "full/path/to/nested.Foo"
def iface_commontype(obj):
if is_iface(obj):
go_type_ptr = obj['tab']['_type']
elif is_eface(obj):
......@@ -197,15 +197,31 @@ def iface_dtype(obj):
else:
return
ct = gdb.lookup_type("struct runtime.commonType").pointer()
dynamic_go_type = go_type_ptr['ptr'].cast(ct).dereference()
# sanity check: reflection type description ends in a loop.
tt = go_type_ptr['_type'].cast(_rtp_type).dereference()['_type']
if tt != tt.cast(_rtp_type).dereference()['_type']:
return
return go_type_ptr['ptr'].cast(_rctp_type).dereference()
def iface_dtype(obj):
"Decode type of the data field of an eface or iface struct."
# known issue: dtype_name decoded from runtime.commonType is "nested.Foo"
# but the dwarf table lists it as "full/path/to/nested.Foo"
dynamic_go_type = iface_commontype(obj)
if dynamic_go_type is None:
return
dtype_name = dynamic_go_type['string'].dereference()['str'].string()
dynamic_gdb_type = lookup_type(dtype_name)
if dynamic_gdb_type:
type_size = int(dynamic_go_type['size'])
uintptr_size = int(dynamic_go_type['size'].type.sizeof) # size is itself an uintptr
if type_size > uintptr_size:
if dynamic_gdb_type is None:
return
type_size = int(dynamic_go_type['size'])
uintptr_size = int(dynamic_go_type['size'].type.sizeof) # size is itself an uintptr
if type_size > uintptr_size:
dynamic_gdb_type = dynamic_gdb_type.pointer()
return dynamic_gdb_type
......@@ -213,15 +229,9 @@ def iface_dtype(obj):
def iface_dtype_name(obj):
"Decode type name of the data field of an eface or iface struct."
if is_iface(obj):
go_type_ptr = obj['tab']['_type']
elif is_eface(obj):
go_type_ptr = obj['_type']
else:
dynamic_go_type = iface_commontype(obj)
if dynamic_go_type is None:
return
ct = gdb.lookup_type("struct runtime.commonType").pointer()
dynamic_go_type = go_type_ptr['ptr'].cast(ct).dereference()
return dynamic_go_type['string'].dereference()['str'].string()
......@@ -244,7 +254,7 @@ class IfacePrinter:
except:
return "<bad dynamic type>"
if not dtype: # trouble looking up, print something reasonable
if dtype is None: # trouble looking up, print something reasonable
return "(%s)%s" % (iface_dtype_name(self.val), self.val['data'])
try:
......@@ -267,7 +277,7 @@ goobjfile.pretty_printers.append(ifacematcher)
class GoLenFunc(gdb.Function):
"Length of strings, slices, maps or channels"
how = ((StringTypePrinter, 'len' ),
how = ((StringTypePrinter, 'len'),
(SliceTypePrinter, 'len'),
(MapTypePrinter, 'count'),
(ChanTypePrinter, 'qcount'))
......@@ -316,7 +326,7 @@ class DTypeFunc(gdb.Function):
# Commands
#
sts = ( 'idle', 'runnable', 'running', 'syscall', 'waiting', 'moribund', 'dead', 'recovery')
sts = ('idle', 'runnable', 'running', 'syscall', 'waiting', 'moribund', 'dead', 'recovery')
def linked_list(ptr, linkfield):
while ptr:
......@@ -339,8 +349,8 @@ class GoroutinesCmd(gdb.Command):
s = ' '
if ptr['m']:
s = '*'
pc = ptr['sched']['pc'].cast(vp)
sp = ptr['sched']['sp'].cast(vp)
pc = ptr['sched']['pc'].cast(vp)
sp = ptr['sched']['sp'].cast(vp)
blk = gdb.block_for_pc(long((pc)))
print s, ptr['goid'], "%8s" % sts[long((ptr['status']))], blk.function
......@@ -382,10 +392,10 @@ class GoroutineCmd(gdb.Command):
gdb.parse_and_eval('$sp = 0x%x' % long(sp))
try:
gdb.execute(cmd)
finally:
finally:
gdb.parse_and_eval('$pc = $save_pc')
gdb.parse_and_eval('$sp = $save_sp')
save_frame.select()
gdb.parse_and_eval('$sp = $save_sp')
save_frame.select()
class GoIfaceCmd(gdb.Command):
......@@ -403,8 +413,12 @@ class GoIfaceCmd(gdb.Command):
print "Can't parse ", obj, ": ", e
continue
dtype = iface_dtype(obj)
if not dtype:
if obj['data'] == 0:
dtype = "nil"
else:
dtype = iface_dtype(obj)
if dtype is None:
print "Not an interface: ", obj.type
continue
......
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