Re: [PATCH] binfmt: turn MAX_ARG_PAGES into a sysctl tunable

[Arjan van de Ven <arjan@linux.intel.com>]

Ingo Molnar wrote:
> at copy_strings_kernel() time we dont yet know where in the target VM to 
> install the pages. A binformat might want to install all sorts of stuff 
> on the stack first, before it constructs the envp and copies the strings 
> themselves. So we dont know the precise alignment needed.
> 
> delaying the copying to setup_arg_pages() time does not seem to work 
> either, because that gets called after the old MM has been destroyed.
> 
> [ delaying the copying will also change behavior in error cases - 
>   instead of returning with an error if the string pointers are bad 
>   we'll have to kill the execve()ing process. ]
> 
> am i missing something?

we could always just have the  binfmt use mremap() equivalent to move it 
into the place it wants...