mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2025-01-31 12:41:49 +01:00
3960b83ba4
X86 Supports Indirect Branch Tracking (IBT) as part of Control-Flow Enforcement Technology (CET). IBT instruments ENDBR instructions used to specify valid targets of indirect call / jmp. The `nocf_check` attribute has two roles in the context of X86 IBT technology: 1. Appertains to a function - do not add ENDBR instruction at the beginning of the function. 2. Appertains to a function pointer - do not track the target function of this pointer by adding nocf_check prefix to the indirect-call instruction. This patch implements `nocf_check` context for Indirect Branch Tracking. It also auto generates `nocf_check` prefixes before indirect branchs to jump tables that are guarded by range checks. Differential Revision: https://reviews.llvm.org/D41879 llvm-svn: 327767