Re: [Help-smalltalk] Fun/Crashes with newer GCC on Debian

[Paolo Bonzini]

Il 12/10/2013 19:11, Holger Hans Peter Freyther ha scritto:
> On Sat, Oct 12, 2013 at 06:45:05PM +0200, Paolo Bonzini wrote:
>> Il 11/10/2013 08:08, Holger Hans Peter Freyther ha scritto:
>>> C-code:
>>>
>>> I get asan reports in _gst_grey_oop_range *page = *page;. With
>>> generations off and NO_INCREMENTAL_GC set. Can't this be a NO-OP?
>>
>> This is done to generate a segfault, but only if the page is still
>> unwritable.  It is definitely a false positive.
> 
> Okay, but with NO_SIGSEGV_HANDLING defined we could avoid this. The
> pages are readable/writable anyway so will not generate a segfault
> while read/written?
> 
> diff --git a/libgst/oop.c b/libgst/oop.c
> index c8af8c6..71e837a 100644
> --- a/libgst/oop.c
> +++ b/libgst/oop.c
> @@ -1630,6 +1630,7 @@ tenure_one_object ()
>  void
>  _gst_grey_oop_range (PTR from, size_t size)
>  {
> +#ifndef NO_SIGSEGV_HANDLING
>    volatile char *last, *page;
>  
>    for (last = ((char *)from) + size,
> @@ -1637,6 +1638,7 @@ _gst_grey_oop_range (PTR from, size_t size)
>         page < last;
>         page += getpagesize())
>      *page = *page;
> +#endif
>  }

Yes, that's correct.

Paolo