pcc added inline comments.
================
Comment at: clang/lib/CodeGen/CGExpr.cpp:3168
+ -1);
+ llvm::Value *Test = Builder.CreateICmpEQ(Builder.CreateLoad(HashPtr), Hash);
+ llvm::BasicBlock *ContBB = createBasicBlock("kcfi.cont");
----------------
We considered a scheme like this before and one problem that we discovered with
comparing the hash in this way is that it can produce gadgets, e.g.
```
movabs $0x0123456789abcdef, %rax
cmp %rax, ...
```
the `cmp`instruction ends up being a valid target address because the `movabs`
instruction ends in the hash. The way we thought about solving this was to
introduce a new intrinsic that would materialize the constant without these
gadgets (e.g. invert the `movabs` operand and follow it by a `not`).
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D119296/new/
https://reviews.llvm.org/D119296
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