Fix lldb disassembler so it works with core files

This fixes the lldb disassembler script so that it doesn't need a live
process when disassembling rb_iseq_t.  I also added the PC to the output
so you can tell what the VM is executing when it crashed.

For example:

```
(lldb) rbdisasm ec->cfp->iseq
PC             IDX  insn_name(operands)
0x56039f0a1720 0000 nop
0x56039f0a1728 0001 getlocal_WC_1( 5 )
0x56039f0a1738 0003 branchunless( 7 )
0x56039f0a1748 0005 getlocal_WC_0( 3 )
0x56039f0a1758 0007 putstring( (VALUE)0x56039f0c7eb8 )
0x56039f0a1768 0009 opt_send_without_block( (struct rb_call_data *)0x56039f09f140 )
0x56039f0a1778 0011 pop
0x56039f0a1780 0012 getglobal( ID: 0x7fd7 )
0x56039f0a1790 0014 branchunless( 7 )
0x56039f0a17a0 0016 getlocal_WC_0( 3 )
0x56039f0a17b0 0018 putstring( (VALUE)0x56039f0c7e90 )
0x56039f0a17c0 0020 opt_send_without_block( (struct rb_call_data *)0x56039f09f150 )
0x56039f0a17d0 0022 pop
0x56039f0a17d8 0023 getlocal_WC_0( 3 )
0x56039f0a17e8 0025 putobject( (VALUE)0x56039f0c7e68 )
0x56039f0a17f8 0027 getlocal_WC_1( 6 )
0x56039f0a1808 0029 dup
0x56039f0a1810 0030 checktype( 5 )
0x56039f0a1820 0032 branchif( 4 )
0x56039f0a1830 0034 dup
0x56039f0a1838 0035 opt_send_without_block( (struct rb_call_data *)0x56039f09f160 )
0x56039f0a1848 0037 tostring
0x56039f0a1850 0038 putobject( (VALUE)0x56039f0c7e40 )
0x56039f0a1860 0040 concatstrings( 3 )
0x56039f0a1870 0042 opt_send_without_block( (struct rb_call_data *)0x56039f09f170 )
0x56039f0a1880 0044 nop
0x56039f0a1888 0045 leave
(lldb) p ec->cfp->pc
(const VALUE *) $146 = 0x000056039f0a1848
```

Here we can see the VM is currently executing `opt_send_without_block`
(because the PC is one ahead of the current instruction)
This commit is contained in:
Aaron Patterson 2020-10-08 16:29:17 -07:00
Родитель c857d0d471
Коммит bca8952fc7
Не найден ключ, соответствующий данной подписи
Идентификатор ключа GPG: 953170BCB4FFAFC6
1 изменённых файлов: 67 добавлений и 25 удалений

Просмотреть файл

@ -73,8 +73,14 @@ class IseqDissassembler:
iseq_size = val.GetValueForExpressionPath("->body->iseq_size").GetValueAsUnsigned()
iseqs = val.GetValueForExpressionPath("->body->iseq_encoded")
idx = 0
print("PC IDX insn_name(operands) ", file=self.result)
while idx < iseq_size:
idx += self.iseq_extract_values(self.debugger, self.target, self.process, self.result, iseqs, idx)
m = self.iseq_extract_values(self.debugger, self.target, self.process, self.result, iseqs, idx)
if m < 1:
print("Error decoding", file=self.result)
return
else:
idx += m
def build_addr2insn(self, target):
tIntPtr = target.FindFirstType("intptr_t")
@ -98,16 +104,21 @@ class IseqDissassembler:
def iseq_extract_values(self, debugger, target, process, result, iseqs, n):
tValueP = target.FindFirstType("VALUE")
sizeofValueP = tValueP.GetByteSize()
insn = target.CreateValueFromAddress(
"i", lldb.SBAddress(iseqs.unsigned + (n * sizeofValueP), target), tValueP)
pc = iseqs.unsigned + (n * sizeofValueP)
insn = target.CreateValueFromAddress("i", lldb.SBAddress(pc, target), tValueP)
addr = insn.GetValueAsUnsigned()
orig_insn = self.rb_vm_insn_addr2insn2(target, result, addr)
name = self.insn_name(target, process, result, orig_insn)
length = self.insn_len(target, orig_insn)
op_types = bytes(self.insn_op_types(target, process, result, orig_insn), 'utf-8')
op_str = self.insn_op_types(target, process, result, orig_insn)
op_types = bytes(op_str, 'utf-8')
print("%04d %s" % (n, name), file=result, end="")
if length != (len(op_types) + 1):
print("error decoding iseqs", file=result)
return -1
print("%0#14x %04d %s" % (pc, n, name), file=result, end="")
if length == 1:
print("", file=result)
@ -131,50 +142,81 @@ class IseqDissassembler:
def insn_len(self, target, offset):
size_of_char = self.tChar.GetByteSize()
addr_of_table = target.FindSymbols("insn_len.t")[0].GetSymbol().GetStartAddress().GetLoadAddress(target)
symbol = target.FindSymbols("insn_len.t")[0].GetSymbol()
section = symbol.GetStartAddress().GetSection()
addr_of_table = symbol.GetStartAddress().GetOffset()
addr_in_table = addr_of_table + (offset * size_of_char)
addr = lldb.SBAddress(addr_in_table, target)
error = lldb.SBError()
length = section.GetSectionData().GetUnsignedInt8(error, addr_of_table + (offset * size_of_char))
return target.CreateValueFromAddress("y", addr, self.tChar).GetValueAsUnsigned()
if error.Success():
return length
else:
print("error getting length: ", error)
def insn_op_types(self, target, process, result, insn):
tUShort = target.FindFirstType("unsigned short")
self.tChar = target.FindFirstType("char")
size_of_short = tUShort.GetByteSize()
size_of_char = self.tChar.GetByteSize()
addr_of_table = target.FindSymbols("insn_op_types.y")[0].GetSymbol().GetStartAddress().GetLoadAddress(target)
addr_in_table = addr_of_table + (insn * size_of_short)
addr = lldb.SBAddress(addr_in_table, target)
offset = target.CreateValueFromAddress("y", addr, tUShort).GetValueAsUnsigned()
symbol = target.FindSymbols("insn_op_types.y")[0].GetSymbol()
section = symbol.GetStartAddress().GetSection()
addr_of_table = symbol.GetStartAddress().GetOffset()
addr_of_table = target.FindSymbols("insn_op_types.x")[0].GetSymbol().GetStartAddress().GetLoadAddress(target)
addr_in_table = addr_of_table + (insn * size_of_short)
error = lldb.SBError()
offset = section.GetSectionData().GetUnsignedInt16(error, addr_in_table)
if not error.Success():
print("error getting op type offset: ", error)
symbol = target.FindSymbols("insn_op_types.x")[0].GetSymbol()
section = symbol.GetStartAddress().GetSection()
addr_of_table = symbol.GetStartAddress().GetOffset()
addr_in_name_table = addr_of_table + (offset * size_of_char)
error = lldb.SBError()
return process.ReadCStringFromMemory(addr_in_name_table, 256, error)
types = section.GetSectionData().GetString(error, addr_in_name_table)
if error.Success():
return types
else:
print("error getting op types: ", error)
def insn_name_table_offset(self, target, offset):
tUShort = target.FindFirstType("unsigned short")
size_of_short = tUShort.GetByteSize()
addr_of_table = target.FindSymbols("insn_name.y")[0].GetSymbol().GetStartAddress().GetLoadAddress(target)
symbol = target.FindSymbols("insn_name.y")[0].GetSymbol()
section = symbol.GetStartAddress().GetSection()
table_offset = symbol.GetStartAddress().GetOffset()
addr_in_table = addr_of_table + (offset * size_of_short)
addr = lldb.SBAddress(addr_in_table, target)
table_offset = table_offset + (offset * size_of_short)
return target.CreateValueFromAddress("y", addr, tUShort).GetValueAsUnsigned()
error = lldb.SBError()
offset = section.GetSectionData().GetUnsignedInt16(error, table_offset)
if error.Success():
return offset
else:
print("error getting insn name table offset: ", error)
def insn_name(self, target, process, result, offset):
tCharP = target.FindFirstType("char*")
addr_of_table = target.FindSymbols("insn_name.x")[0].GetSymbol().GetStartAddress().GetLoadAddress(target)
symbol = target.FindSymbols("insn_name.x")[0].GetSymbol()
section = symbol.GetStartAddress().GetSection()
addr_of_table = symbol.GetStartAddress().GetOffset()
name_table_offset = self.insn_name_table_offset(target, offset)
addr_in_name_table = addr_of_table + name_table_offset
addr_in_name_table = addr_of_table + self.insn_name_table_offset(target, offset)
addr = lldb.SBAddress(addr_in_name_table, target)
error = lldb.SBError()
return process.ReadCStringFromMemory(addr_in_name_table, 256, error)
name = section.GetSectionData().GetString(error, addr_in_name_table)
if error.Success():
return name
else:
print('error getting insn name', error)
def disasm(debugger, command, result, internal_dict):
disassembler = IseqDissassembler(debugger, command, result, internal_dict)