Re: linux-user: Add option to run `execve`d programs through QEMU

[Noah Goldstein]

On Wed, Nov 6, 2024 at 3:10 PM Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> On 11/6/24 18:13, Noah Goldstein wrote:
> > Question about impl regarding handling of `-execfd` with/without a program 
> > name.
> >
> > 1) `-execfd` + program name ie: `qemu -execfd <some_fd> ls -a`.
> > 2) `-execfd` without program name i.e: `qemu -execfd <some_fd> -a`.
> >
> > Do you want to allow both of these? If you want to allow (1), what should
> > we use for `argv[0]`/`exec_path`. The program pass ("ls") or
> > `readlink(<some_fd>)`?
>
> The canonical response is, examine the kernel source.
> We're not implementing this in a vacuum, you're replicating execveat(2).
>
> I suspect the answer is (1), to be compared with
>
>      syscall(__NR_execveat, some_fd, "", &["ls", "-a"], env, AT_EMPTY_PATH);

Err, I think the reference for '-execfd' is `fexecve`:
https://man7.org/linux/man-pages/man3/fexecve.3.html

Which doesn't take a path. So I guess we just interpret the "ls" as
argv[0] but not
as "exec_path".
>
>
> r~