[PATCH v2 7/8] exec: Generic execfd support

[Rob Landley]

On 5/18/20 7:33 PM, Eric W. Biederman wrote:
> 
> Most of the support for passing the file descriptor of an executable
> to an interpreter already lives in the generic code and in binfmt_elf.
> Rework the fields in binfmt_elf that deal with executable file
> descriptor passing to make executable file descriptor passing a first
> class concept.

I was reading this to try to figure out how to do execve(NULL, argv[], envp) to
re-exec self after a vfork() in a chroot with no /proc, and hit the most trivial
quibble ever:

> --- a/fs/exec.c
> +++ b/fs/exec.c
> @@ -1323,7 +1323,10 @@ int begin_new_exec(struct linux_binprm * bprm)
>  	 */
>  	set_mm_exe_file(bprm->mm, bprm->file);
>  
> +	/* If the binary is not readable than enforce mm->dumpable=0 */

then

Rob