On Mon, Jul 1, 2024 at 1:53 PM Jason A. Donenfeld [off-list ref] wrote:

On Fri, Jun 28, 2024 at 04:09:01PM +0200, Jason A. Donenfeld wrote:

quoted

fine. Also I used u32 there for the two smaller arguments, but maybe
that's silly and we should go straight to u64?

Judging by `struct clone_args`, it looks like I've got to use
__aligned_u64 for every argument:

    struct clone_args {
        __aligned_u64 flags;
        __aligned_u64 pidfd;
        __aligned_u64 child_tid;
        __aligned_u64 parent_tid;
        __aligned_u64 exit_signal;
        __aligned_u64 stack;
        __aligned_u64 stack_size;
        __aligned_u64 tls;
        __aligned_u64 set_tid;
        __aligned_u64 set_tid_size;
        __aligned_u64 cgroup;
    };
    #define CLONE_ARGS_SIZE_VER0 64 /* sizeof first published struct */
    #define CLONE_ARGS_SIZE_VER1 80 /* sizeof second published struct */
    #define CLONE_ARGS_SIZE_VER2 88 /* sizeof third published struct */

So okay, I'll do that, and will have an ARGS_SIZE_VER0 macro too.

This is now covered by v19 of this patchset:
https://lore.kernel.org/lkml/20240701135801.3698-1-Jason@zx2c4.com/ (local)