691ca556e0
RISC-V Zicfiss-based shadow stack needs to let the linker/loader know if the binary is built with the mechanism enabled to support proper link-time/load-time management of this feature. The information is encoded as a bit in the `.note.gnu.property` section. This patch implements emitting the section for RISC-V targets when Zicfiss-based shadow stack is enabled. When Clang receives the `-fcf-protection=return` flag, it adds the `hw-shadow-stack` attribute to LLVM functions, and adds a non-zero valued attribute named `cf-protection-return` to the LLVM module it generates. The backend depends on the `hw-shadow-stack` attributes to generate Zicfiss-based shadow stack instructions for each function, but at the module scope, the `cf-protection-return` attribute is a better indication of whether the translation unit is built with Zicfiss-based shadow stack enabled, so this patch emits the `.note.gnu.property` section with the "Zicfiss-based shadow stack" bit toggled on when it sees the `cf-protection-return` attribute.
32 lines
1.1 KiB
LLVM
32 lines
1.1 KiB
LLVM
; RUN: llc --mtriple=riscv32 --filetype=obj -o - %s | llvm-readelf -n - | FileCheck --check-prefixes=READELF %s
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; RUN: llc --mtriple=riscv64 --filetype=obj -o - %s | llvm-readelf -n - | FileCheck --check-prefixes=READELF %s
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; RUN: llc --mtriple=riscv32 -o - %s | FileCheck --check-prefixes=ASM,ASM32 %s
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; RUN: llc --mtriple=riscv64 -o - %s | FileCheck --check-prefixes=ASM,ASM64 %s
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; READELF: Properties: RISC-V feature: ZICFISS
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; ASM: .section ".note.GNU-stack","",@progbits
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; ASM-NEXT: .section .note.gnu.property,"a",@note
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; ASM-NEXT: .word 4
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; ASM-NEXT: .word .Ltmp1-.Ltmp0
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; ASM-NEXT: .word 5
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; ASM-NEXT: .asciz "GNU"
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; ASM-NEXT: .Ltmp0:
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; ASM32-NEXT: .p2align 2, 0x0
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; ASM64-NEXT: .p2align 3, 0x0
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; ASM-NEXT: .word 3221225472
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; ASM-NEXT: .word 4
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; ASM-NEXT: .word 2
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; ASM32-NEXT: .p2align 2, 0x0
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; ASM64-NEXT: .p2align 3, 0x0
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; ASM-NEXT: .Ltmp1:
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define i32 @f() "hw-shadow-stack" {
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entry:
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ret i32 0
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}
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!llvm.module.flags = !{!0}
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!0 = !{i32 8, !"cf-protection-return", i32 1}
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