On Thu, Mar 26, 2020 at 07:45:13AM -0500, Eric W. Biederman wrote:
> > On Wed 25-03-20 17:20:40, Eric W. Biederman wrote:
> plus I want to get very far away from the incorrect idea that you
> can have sysctls without compiling in proc support. That is not how
> the code works, that is not how the code is tested.
Agreed.
> It is also worth pointing out that:
>
> proc_mnt = kern_mount(proc_fs_type);
> for_each_sysctl_cmdline() {
> ...
> file = file_open_root(proc_mnt->mnt_root, proc_mnt, sysctl_path, O_WRONLY, 0);
> kernel_write(file, value, value_len);
> }
> kern_umount(proc_mnt);
>
> Is not an unreasonable implementation.
This:
> There are problems with a persistent mount of proc in that it forces
> userspace not to use any proc mount options. But a temporary mount of
> proc to deal with command line options is not at all unreasonable.
> Plus it looks like we can have kern_write do all of the kernel/user
> buffer silliness.
Is a bit of tribal knowledge worth documenting for the approach taken
forward. Vlastimil can you add a little comment mentioning some of this
logic?
Luis
