[uClinux-dev] [PATCH] : Avoid filename < TASK_SIZE test in do_getname() when no MMU

Greg Ungerer gerg at snapgear.com
Tue May 25 22:54:49 EDT 2010


Hi Philippe,

Philippe De Muyter wrote:
> Hi Greg,
> 
> On Tue, May 25, 2010 at 11:19:43AM +1000, Greg Ungerer wrote:
>> Hi Philippe,
>>
>> Philippe De Muyter wrote:
>>> On Mon, May 24, 2010 at 11:29:50AM +1000, Greg Ungerer wrote:
>>> [...]
>>>> +#else
>>>> +#define TASK_SIZE	(0xFFFFFFFFUL)
>>>> +#endif
>>> Because of do_getname() :
>>> 	len = TASK_SIZE - (unsigned long) filename;
>>> we should rather have
>>> 	#define TASK_SIZE (0x100000000ull)
>> I see what you mean. But in practice here I don't think it matters.
> 
> Can no process have its stack allocated in the last block, and hence have some
> argv[i] put in the last addresses, with the terminating '\0' at 0xffffffff ?

I think that is possible. But the "in practice" part is that
I don't know of any m68knommu platforms that actually map the RAM
right at the very top of the 32bit address space - so that it ends
at 0xffffffff.

Regards
Greg


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Greg Ungerer  --  Principal Engineer        EMAIL:     gerg at snapgear.com
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