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

[Greg Clayton via lldb-dev]

> On Sep 19, 2016, at 10:33 AM, Lei Kong <leikong at msn.com> wrote:
> 
> 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

You actually want to get the load address when reading from memory. This should be:

def vtable_addr (vtableSymbol, target):
    return vtableSymbol.addr.GetLoadAddress(target) + 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
> Sent: Monday, September 19, 2016 09:12 AM
> To: Lei Kong
> Cc: Jim Ingham; 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
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> > > 
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