[cfe-commits] [PATCH][libcxxabi] loop boundary bug in personality routine when scanning eh table

[Wen-Han Gu (谷汶翰)]

Hi all,

If this patch seems good, could any one helps commit?
If not, please let me know the problem. :)

Thanks.

2012/11/2 Wen-Han Gu (谷汶翰) <wenhan.gu at gmail.com>

> Hello Howard,
>
> It did happen on ARM and x86_32, and I guess all targets have this bug.
> This bug behaves depending on the upcoming entry, might be nothing,
> infinite loop, other errors...
>
> Thanks.
>
>
> 2012/11/2 Howard Hinnant <hhinnant at apple.com>
>
>> On Nov 1, 2012, at 5:32 AM, Wen-Han Gu (谷汶翰) <wenhan.gu at gmail.com> wrote:
>>
>> > Dear cfe-commits and libcxxabi developers,
>> >
>> > I hit a bug in libc++abi when testing on a gcc testsuite sample.
>> > This can be fixed simply by this small patch.
>> > Please help review it. Thanks in advance!
>> >
>> >
>> > Index: src/cxa_personality.cpp
>> > ===================================================================
>> > --- src/cxa_personality.cpp     (revision 167216)
>> > +++ src/cxa_personality.cpp     (working copy)
>> > @@ -552,7 +552,7 @@
>> >      const uint8_t* callSiteTableEnd = callSiteTableStart +
>> callSiteTableLength;
>> >      const uint8_t* actionTableStart = callSiteTableEnd;
>> >      const uint8_t* callSitePtr = callSiteTableStart;
>> > -    while (true)
>> > +    while (callSitePtr < callSiteTableEnd)
>> >      {
>> >          // There is one entry per call site.
>> >  #if !__arm__
>> > @@ -782,7 +782,12 @@
>> >              call_terminate(native_exception, unwind_exception);
>> >          }
>> >  #endif  // !__arm__
>> > -    }  // there is no break out of this loop, only return
>> > +    }  // there might be some tricky cases which break out of this loop
>> > +
>> > +    // If we are here, it means no eh table entry specify how to handle
>> > +    // this exception. For example, gcc testsuites eh23 at
>> > +    // <gcc>/gcc/testsuite/g++.old-deja/g++.mike/eh23.C
>> > +    call_terminate(native_exception, unwind_exception);
>> >  }
>> >
>> >  // public API
>>
>> Thanks for the patch.  Was this on __arm__ and was the symptom an
>> infinite loop?
>>
>> Howard
>>
>>
>>
>
>
> --
> Best regards,
> Wen-Han Gu (Nowar)
>
>


-- 
Best regards,
Wen-Han Gu (Nowar)
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