# Re: \[PATCH v19 7/7\] x86/vdso: Insert endbr32/endbr64 to vDSO

- From: Kees Cook \<hidden\>
- Date: 2021-02-04 19:58:01 
- List: linux-api
- Page: https://ratatoskr.run/linux-api/2021/02/6259095
- Thread: https://ratatoskr.run/linux-doc/2021/02/6257808/t.md

```text
On Wed, Feb 03, 2021 at 02:59:02PM -0800, Yu-cheng Yu wrote:
> From: "H.J. Lu" <redacted>
> 
> When Indirect Branch Tracking (IBT) is enabled, vDSO functions may be
> called indirectly, and must have ENDBR32 or ENDBR64 as the first
> instruction.  The compiler must support -fcf-protection=branch so that it
> can be used to compile vDSO.
> 
> Signed-off-by: H.J. Lu <redacted>

Reviewed-by: Kees Cook <redacted>

-- 
Kees Cook
```