Re: [PATCH 2/7] [D] libiberty: Fail if reached end of symbol string

[Iain Buclaw <ibuclaw at gdcproject dot org>]

On 14 May 2015 at 16:51, Jeff Law <law@redhat.com> wrote:
> On 05/14/2015 07:36 AM, Iain Buclaw wrote:
>>
>> On 14 May 2015 at 14:58, Jeff Law <law@redhat.com> wrote:
>>>
>>> On 05/13/2015 02:51 AM, Iain Buclaw wrote:
>>>>
>>>>
>>>> If a symbol that has so far been valid abruptly ends then we will want
>>>> to fail the process rather than silently succeed.
>>>>
>>>> ---
>>>> libiberty/ChangeLog
>>>>
>>>> 2015-05-13 Iain Buclaw  <ibuclaw@gdcproject.org>
>>>>
>>>>       * d-demangle.c (dlang_call_convention): Return NULL if have
>>>> reached
>>>> the
>>>>       end of the symbol, but expected more.
>>>>       (dlang_attributes): Likewise.
>>>>       (dlang_function_type): Likewise.
>>>>       (dlang_type): Likewise.
>>>>       (dlang_identifier): Likewise.
>>>>       (dlang_value): Likewise.
>>>
>>>
>>> I spot checked various callers of these functions that not return NULL
>>> and
>>> they looked reasonable. Though I was a bit concerned about the callers of
>>> dlang_type, dlang_value and dlang_identifier.
>>>
>>> In those cases we'll often still do the string_append, string_setlength
>>> and
>>> other calls in the caller of dlang_{value,type,identifier}.  I'm assuming
>>> that's safe (the error still appears to be bubbling up properly).
>>>
>>
>> The string routines should be safe for that (appending a string with a
>> zero length does nothing, for instance).
>>
>>> If you can confirm that we're OK in those cases, then this is OK for the
>>> trunk.
>>>
>>
>> I can start fuzzing mangle strings to test that failures actually fail
>> gracefully.  There's already a fuzzer that exists for C++, I think the
>> only change that would be required for D is exchanging "_Z" for "_D"
>> and calling cplus_demangle with DMGL_DLANG.
>
> Your call whether to fuzz before or after committing the changes.
>
> jeff

Iant commited in the changes first time around.  I don't have write
after approval access in GCC just yet, probably should go about
getting that sorted out if this is to become a regular thing.  I dealt
with copyright assignments back in September.

Iain.