Re: [PATCH v19 3/7] x86/cet/ibt: Handle signals for Indirect Branch Tracking
- From
- Kees Cook <hidden>
- Date
- 2021-02-04 20:17:52
- Also in
- linux-api, linux-doc, linux-mm, lkml
- Reply to
- Yu-cheng Yu, 2021-02-03
On Wed, Feb 03, 2021 at 02:58:58PM -0800, Yu-cheng Yu wrote:
When an indirect CALL/JMP instruction is executed and before it reaches the target, it is in 'WAIT_ENDBR' status, which can be read from MSR_IA32_U_CET. The status is part of a task's status before a signal is raised and preserved in the signal frame. It is restored for sigreturn. IBT state machine is described in Intel SDM Vol. 1, Sec. 18.3. Signed-off-by: Yu-cheng Yu <redacted>
Reviewed-by: Kees Cook <redacted> -- Kees Cook