Re: vdso handling

Pedro Alves
2014-03-21T15:55:00Z

On 03/20/2014 01:59 AM, Alan Modra wrote:
> On Wed, Mar 19, 2014 at 08:29:47AM +0000, Metzger, Markus T wrote:
>> Shouldn't the ehdr indicate that there are no sections in this case?
>
> Nope. See my other email to Pedro.
>
>> If we can't trust the image to contain everything that the ELF header
>> describes, would it be safer to generate fake sections based on the
>> program header? We already assume that the program header is
>> contained in the image.
>
> Yes, you're correct that it is wrong to assume program headers are
> loaded. Even worse, the in-memory image doesn't even need to contain
> the ELF file header.

Yeah, and I was just assuming it didn't, hence my "just trust the
headers" push before.

I'm now thinking that we'll need pseudo-sections from program
headers anyway, so I'd suggest going in that direction, leaving
the add-symbol-file-from-memory command's intention generic,
and leave revisiting how gdb retrieves the vdso itself off of
memory for another day.

--
Pedro Alves