# Re: \[PATCH v13 1/3\] fs: Add trusted\_for(2) syscall implementation and related sysctl

- From: Kees Cook \<hidden\>
- Date: 2021-10-07 19:25:36 
- List: linux-security-module
- Page: https://ratatoskr.run/linux-security-module/2021/10/215590
- Thread: https://ratatoskr.run/linux-api/2021/10/215579/t.md

```text
On Thu, Oct 07, 2021 at 08:23:18PM +0200, Mickaël Salaün wrote:
> From: Mickaël Salaün <redacted>
> 
> The trusted_for() syscall enables user space tasks to check that files
> are trusted to be executed or interpreted by user space.  This may allow
> script interpreters to check execution permission before reading
> commands from a file, or dynamic linkers to allow shared object loading.
> This may be seen as a way for a trusted task (e.g. interpreter) to check
> the trustworthiness of files (e.g. scripts) before extending its control
> flow graph with new ones originating from these files.
> [...]
>  aio-nr & aio-max-nr
> @@ -382,3 +383,52 @@ Each "watch" costs roughly 90 bytes on a 32bit kernel, and roughly 160 bytes
>  on a 64bit one.
>  The current default value for  max_user_watches  is the 1/25 (4%) of the
>  available low memory, divided for the "watch" cost in bytes.
> +
> +
> +trust_policy
> +------------

bikeshed: can we name this "trusted_for_policy"? Both "trust" and
"policy" are very general words, but "trusted_for" (after this series)
will have a distinct meaning, so "trusted_for_policy" becomes more
specific/searchable.

With that renamed, I think it looks good! I'm looking forward to
interpreters using this. :)

Acked-by: Kees Cook <redacted>

-- 
Kees Cook
```