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| author | Oren Ben Simhon <oren.ben.simhon@intel.com> | 2018-03-17 13:29:46 +0000 |
|---|---|---|
| committer | Oren Ben Simhon <oren.ben.simhon@intel.com> | 2018-03-17 13:29:46 +0000 |
| commit | fdd72fd5225dedb4431473fb3ac7b3d45fc8ed00 (patch) | |
| tree | b1819bd5c756e40209091ea07d752efab4cf83ac /llvm/lib/IR/Attributes.cpp | |
| parent | dbcf1bf503880084e33e57e9fb916a66703d18d7 (diff) | |
| download | bcm5719-llvm-fdd72fd5225dedb4431473fb3ac7b3d45fc8ed00.tar.gz bcm5719-llvm-fdd72fd5225dedb4431473fb3ac7b3d45fc8ed00.zip | |
[X86] Added support for nocf_check attribute for indirect Branch Tracking
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
Diffstat (limited to 'llvm/lib/IR/Attributes.cpp')
| -rw-r--r-- | llvm/lib/IR/Attributes.cpp | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/llvm/lib/IR/Attributes.cpp b/llvm/lib/IR/Attributes.cpp index 30216bcde68..0aea24f22c0 100644 --- a/llvm/lib/IR/Attributes.cpp +++ b/llvm/lib/IR/Attributes.cpp @@ -299,6 +299,8 @@ std::string Attribute::getAsString(bool InAttrGrp) const { return "noredzone"; if (hasAttribute(Attribute::NoReturn)) return "noreturn"; + if (hasAttribute(Attribute::NoCfCheck)) + return "nocf_check"; if (hasAttribute(Attribute::NoRecurse)) return "norecurse"; if (hasAttribute(Attribute::NoUnwind)) |
