Re: [PATCH v28 04/10] x86/cet/ibt: Disable IBT for ia32
From: Andy Lutomirski <luto@kernel.org>
Date: 2021-08-09 23:04:35
Also in:
linux-api, linux-arch, linux-mm, lkml
On 7/22/21 1:57 PM, Yu-cheng Yu wrote:
In a signal, a task's IBT status needs to be saved to the signal frame, and later restored in sigreturn. For the purpose, previous versions of the series add a new struct to the signal frame. However, a new signal frame format (or re-using a reserved space) introduces complex compatibility issues. In the discussion (see link below), Andy Lutomirski proposed using a ucontext flag. The approach is clean and eliminates most compatibility issues. However, a legacy IA32 signal frame does not have ucontext and cannot support a uc flag. Thus, - Disable IBT for ia32. - In ia32 sigreturn, verify ibt is disabled.
Acked-by: Andy Lutomirski <luto@kernel.org>