a88c722e68
PAC/BTI-related codegen in the AArch64 backend is controlled by a set of LLVM IR function attributes, added to the function by Clang, based on command-line options and GCC-style function attributes. However, functions, generated in the LLVM middle end (for example, asan.module.ctor or __llvm_gcov_write_out) do not get any attributes and the backend incorrectly does not do any PAC/BTI code generation. This patch record the default state of PAC/BTI codegen in a set of LLVM IR module-level attributes, based on command-line options: * "sign-return-address", with non-zero value means generate code to sign return addresses (PAC-RET), zero value means disable PAC-RET. * "sign-return-address-all", with non-zero value means enable PAC-RET for all functions, zero value means enable PAC-RET only for functions, which spill LR. * "sign-return-address-with-bkey", with non-zero value means use B-key for signing, zero value mean use A-key. This set of attributes are always added for AArch64 targets (as opposed, for example, to interpreting a missing attribute as having a value 0) in order to be able to check for conflicts when combining module attributed during LTO. Module-level attributes are overridden by function level attributes. All the decision making about whether to not to generate PAC and/or BTI code is factored out into AArch64FunctionInfo, there shouldn't be any places left, other than AArch64FunctionInfo, which directly examine PAC/BTI attributes, except AArch64AsmPrinter.cpp, which is/will-be handled by a separate patch. Differential Revision: https://reviews.llvm.org/D85649
33 lines
1.0 KiB
LLVM
33 lines
1.0 KiB
LLVM
;; RUN: llc %s -o -| FileCheck %s
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target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"
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target triple = "aarch64-unknown-linux"
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@llvm.global_ctors = appending global [1 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 1, void ()* @asan.module_ctor, i8* null }]
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define dso_local i32 @f() #0 {
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entry:
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ret i32 0
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}
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;; CHECK-LABEL: f:
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;; CHECK: hint #34
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declare void @__asan_init()
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declare void @__asan_version_mismatch_check_v8()
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define internal void @asan.module_ctor() {
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call void @__asan_init()
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call void @__asan_version_mismatch_check_v8()
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ret void
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}
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;; CHECK-LABEL: asan.module_ctor:
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;; CHECK: hint #34
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attributes #0 = { noinline nounwind optnone sanitize_address uwtable "branch-target-enforcement"="true" }
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!llvm.module.flags = !{!0, !1, !2, !3, !4}
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!0 = !{i32 1, !"wchar_size", i32 4}
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!1 = !{i32 4, !"branch-target-enforcement", i32 1}
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!2 = !{i32 4, !"sign-return-address", i32 0}
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!3 = !{i32 4, !"sign-return-address-all", i32 0}
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!4 = !{i32 4, !"sign-return-address-with-bkey", i32 0} |