[lldb-dev] OverflowError: in method 'SBProcess_ReadPointerFromMemory', argument 2 of type 'lldb::addr_t'

[Lei Kong via lldb-dev]

You are right, it seems the argument is out of range, both vtableAddr and vtableAddr-8 are “8.5” byte long. Maybe there is something wrong with the way I get vtableAddress? I will clean up my full script and send it to you if the following does not provide enough information, thanks much.

def vtable_addr (vtableSymbol):
    return vtableSymbol.addr.section.file_addr + vtableSymbol.addr.offset + 0x10


vtableAddr, type=<type 'long'>, value=0x1000000000000000f
vtableAddr-8, type=<type 'long'>, value=0x10000000000000007
Traceback (most recent call last):
  File "<input>", line 1, in <module>
  File "/home/leikong/repo/WindowsFabric/build.prod/test/fabdbg.py", line 199, in findall
    findtypes(pattern,ignorePureVirtualType)
  File "/home/leikong/repo/WindowsFabric/build.prod/test/fabdbg.py", line 156, in findtypes
    if ignorePureVirtualType and has_pure_virtual(vtableAddr, pureVirtualFuncs) :
  File "/home/leikong/repo/WindowsFabric/build.prod/test/fabdbg.py", line 100, in has_pure_virtual
    vtableEndAddr = lldb.process.ReadPointerFromMemory(vtableAddr-8, error)
  File "/home/leikong/bin/lldb/lib/python2.7/site-packages/lldb/__init__.py", line 9418, in ReadPointerFromMemory
    return _lldb.SBProcess_ReadPointerFromMemory(self, addr, error)
OverflowError: in method 'SBProcess_ReadPointerFromMemory', argument 2 of type 'lldb::addr_t'

From: Greg Clayton<mailto:gclayton at apple.com>
Sent: Monday, September 19, 2016 09:12 AM
To: Lei Kong<mailto:leikong at msn.com>
Cc: Jim Ingham<mailto:jingham at apple.com>; lldb-dev at lists.llvm.org<mailto:lldb-dev at lists.llvm.org>
Subject: Re: [lldb-dev] OverflowError: in method 'SBProcess_ReadPointerFromMemory', argument 2 of type 'lldb::addr_t'

Try printing the type of the value you are passing in the line:

    vtableEndAddr = lldb.process.ReadPointerFromMemory(vtableAddr-8, error)

print type(vtableAddr)
print type(vtableAddr-8)

It seems like it thinks vtableAddr doesn't fit into a lldb::addr_t which is a uint64_t



> On Sep 16, 2016, at 7:39 PM, Lei Kong via lldb-dev <lldb-dev at lists.llvm.org> wrote:
>
> I tried printing error.descryption, but it didn't work, because when the error happens, it seems ReadPointerFromMemory never returned to my code.
>
>
> read from address 0000000001223f68
> Traceback (most recent call last):
>   File "<input>", line 1, in <module>
>   File "/home/leikong/repo/WindowsFabric/build.prod/test/fabdbg.py", line 289, in findall
>     findtypes(pattern,ignorePureVirtualType)
>   File "/home/leikong/repo/WindowsFabric/build.prod/test/fabdbg.py", line 246, in findtypes
>     if ignorePureVirtualType and has_pure_virtual(vtableAddr, pureVirtualFuncs) :
>   File "/home/leikong/repo/WindowsFabric/build.prod/test/fabdbg.py", line 190, in has_pure_virtual
>     vtableEndAddr = lldb.process.ReadPointerFromMemory(vtableAddr-8, error)
>   File "/home/leikong/bin/lldb/lib/python2.7/site-packages/lldb/__init__.py", line 9418, in ReadPointerFromMemory
>     return _lldb.SBProcess_ReadPointerFromMemory(self, addr, error)
> OverflowError: in method 'SBProcess_ReadPointerFromMemory', argument 2 of type 'lldb::addr_t'
>
>
> > Subject: Re: [lldb-dev] OverflowError: in method 'SBProcess_ReadPointerFromMemory', argument 2 of type 'lldb::addr_t'
> > From: jingham at apple.com
> > Date: Fri, 16 Sep 2016 17:12:24 -0700
> > CC: lldb-dev at lists.llvm.org
> > To: leikong at msn.com
> >
> > You passed an error into ReadPointerFromMemory. In the cases where you aren't getting what you expect, what does that error say?
> >
> > Jim
> >
> > > On Sep 16, 2016, at 5:06 PM, Lei Kong via lldb-dev <lldb-dev at lists.llvm.org> wrote:
> > >
> > > I ran into the error in the subject when running a python script with "script myfile.myscript()".
> > >
> > > The value addr_t parameter used is 0x0000000001223f68, the following works fine:
> > >
> > > (lldb) scr
> > > Python Interactive Interpreter. To exit, type 'quit()', 'exit()' or Ctrl-D.
> > > >>> e = lldb.SBError()
> > > >>> ptr = lldb.process.ReadPointerFromMemory(0x0000000001223f68, e)
> > > >>> print ptr
> > > 0
> > > >>>
> > >
> > > Any suggestion how to further investigate? Thanks.
> > >
> > > myfile.myscript() calls the following function in a loop (iterate through all vtable symbols), which contains the call ReadPointerFromMemory.
> > >
> > > def dump_vtbl(vtableAddr) :
> > > error = lldb.SBError()
> > > vtableEndAddr = lldb.process.ReadPointerFromMemory(vtableAddr+8, error)
> > > if not error.success :
> > > return False
> > > print "vtable: [%0.16x, %0.16x)" % (vtableAddr, vtableEndAddr)
> > > for addr in range(vtableAddr, vtableEndAddr, 8) :
> > > print "read from address %.016x" % addr
> > > try:
> > > funcAddr = lldb.process.ReadPointerFromMemory(addr, error)
> > > except:
> > > sys.exc_clear()
> > > continue
> > > if not error.success :
> > > continue
> > >
> > > _______________________________________________
> > > lldb-dev mailing list
> > > lldb-dev at lists.llvm.org
> > > http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-dev
> >
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