llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang-codegen Author: Ahmed Bougacha (ahmedbougacha) <details> <summary>Changes</summary> We already ended up with -fptrauth-returns, the feature macro, the lang opt, and the actual backend lowering. The only part left is threading it all through PointerAuthOptions, to drive the addition of the "ptrauth-returns" attribute to generated functions. This also adds ptrauth_key_return_address to ptrauth.h. --- Full diff: https://github.com/llvm/llvm-project/pull/102416.diff 4 Files Affected: - (modified) clang/include/clang/Basic/PointerAuthOptions.h (+3) - (modified) clang/lib/CodeGen/CodeGenFunction.cpp (+2) - (modified) clang/lib/Frontend/CompilerInvocation.cpp (+3-1) - (modified) clang/lib/Headers/ptrauth.h (+6) ``````````diff diff --git a/clang/include/clang/Basic/PointerAuthOptions.h b/clang/include/clang/Basic/PointerAuthOptions.h index 8f63cf2ad2bf2..a847bf4a4b4f6 100644 --- a/clang/include/clang/Basic/PointerAuthOptions.h +++ b/clang/include/clang/Basic/PointerAuthOptions.h @@ -163,6 +163,9 @@ class PointerAuthSchema { }; struct PointerAuthOptions { + /// Should return addresses be authenticated? + bool ReturnAddresses = false; + /// Do indirect goto label addresses need to be authenticated? bool IndirectGotos = false; diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp index af201554898f3..4dc57d0ff5b26 100644 --- a/clang/lib/CodeGen/CodeGenFunction.cpp +++ b/clang/lib/CodeGen/CodeGenFunction.cpp @@ -880,6 +880,8 @@ void CodeGenFunction::StartFunction(GlobalDecl GD, QualType RetTy, // Add pointer authentication attributes. const CodeGenOptions &CodeGenOpts = CGM.getCodeGenOpts(); + if (CodeGenOpts.PointerAuth.ReturnAddresses) + Fn->addFnAttr("ptrauth-returns"); if (CodeGenOpts.PointerAuth.FunctionPointers) Fn->addFnAttr("ptrauth-calls"); if (CodeGenOpts.PointerAuth.IndirectGotos) diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp index 225bd6416ce5f..e206cfe417261 100644 --- a/clang/lib/Frontend/CompilerInvocation.cpp +++ b/clang/lib/Frontend/CompilerInvocation.cpp @@ -1511,13 +1511,15 @@ void CompilerInvocation::setDefaultPointerAuthOptions( } } Opts.IndirectGotos = LangOpts.PointerAuthIndirectGotos; + Opts.ReturnAddresses = LangOpts.PointerAuthReturns; } static void parsePointerAuthOptions(PointerAuthOptions &Opts, const LangOptions &LangOpts, const llvm::Triple &Triple, DiagnosticsEngine &Diags) { - if (!LangOpts.PointerAuthCalls && !LangOpts.PointerAuthIndirectGotos) + if (!LangOpts.PointerAuthCalls && !LangOpts.PointerAuthIndirectGotos && + !LangOpts.PointerAuthReturns) return; CompilerInvocation::setDefaultPointerAuthOptions(Opts, LangOpts, Triple); diff --git a/clang/lib/Headers/ptrauth.h b/clang/lib/Headers/ptrauth.h index 6cbdccff9a4c1..d489a67c533d4 100644 --- a/clang/lib/Headers/ptrauth.h +++ b/clang/lib/Headers/ptrauth.h @@ -28,6 +28,12 @@ typedef enum { /* A process-specific key which can be used to sign data pointers. */ ptrauth_key_process_dependent_data = ptrauth_key_asdb, + /* The key used to sign return addresses on the stack. + The extra data is based on the storage address of the return address. + On AArch64, that is always the storage address of the return address + 8 + (or, in other words, the value of the stack pointer on function entry) */ + ptrauth_key_return_address = ptrauth_key_process_dependent_code, + /* The key used to sign C function pointers. The extra data is always 0. */ ptrauth_key_function_pointer = ptrauth_key_process_independent_code, `````````` </details> https://github.com/llvm/llvm-project/pull/102416 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
