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llvm-mirror/test/CodeGen/AArch64/patchable-function-entry-bti.ll

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[AsmPrinter] Omit unique ID for __patchable_function_entries sections Follow-up for D74006. When the integrated assembler is used, we use SHF_LINK_ORDER. The linked-to symbol is part of ELFSectionKey, thus we can omit the unique ID.
2020-02-15 05:35:04 +01:00
; RUN: llc -mtriple=aarch64 %s -o - | FileCheck %s
[CodeGen] Move fentry-insert, xray-instrumentation and patchable-function before addPreEmitPass() This intention is to move patchable-function before aarch64-branch-targets (configured in AArch64PassConfig::addPreEmitPass) so that we emit BTI before NOPs (see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92424). This also allows addPreEmitPass() passes to know the precise instruction sizes if they want. Tried x86-64 Debug/Release builds of ccls with -fxray-instrument -fxray-instruction-threshold=1. No output difference with this commit and the previous commit.
2020-01-19 06:44:06 +01:00
[AArch64] PAC/BTI code generation for LLVM generated functions 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
2020-09-25 12:45:22 +02:00
define void @f0() "patchable-function-entry"="0" "branch-target-enforcement"="true" {
[CodeGen] Move fentry-insert, xray-instrumentation and patchable-function before addPreEmitPass() This intention is to move patchable-function before aarch64-branch-targets (configured in AArch64PassConfig::addPreEmitPass) so that we emit BTI before NOPs (see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92424). This also allows addPreEmitPass() passes to know the precise instruction sizes if they want. Tried x86-64 Debug/Release builds of ccls with -fxray-instrument -fxray-instruction-threshold=1. No output difference with this commit and the previous commit.
2020-01-19 06:44:06 +01:00
; CHECK-LABEL: f0:
Add function attribute "patchable-function-prefix" to support -fpatchable-function-entry=N,M where M>0 Similar to the function attribute `prefix` (prefix data), "patchable-function-prefix" inserts data (M NOPs) before the function entry label. -fpatchable-function-entry=2,1 (1 NOP before entry, 1 NOP after entry) will look like: ``` .type foo,@function .Ltmp0: # @foo nop foo: .Lfunc_begin0: # optional `bti c` (AArch64 Branch Target Identification) or # `endbr64` (Intel Indirect Branch Tracking) nop .section __patchable_function_entries,"awo",@progbits,get,unique,0 .p2align 3 .quad .Ltmp0 ``` -fpatchable-function-entry=N,0 + -mbranch-protection=bti/-fcf-protection=branch has two reasonable placements (https://gcc.gnu.org/ml/gcc-patches/2020-01/msg01185.html): ``` (a) (b) func: func: .Ltmp0: bti c bti c .Ltmp0: nop nop ``` (a) needs no additional code. If the consensus is to go for (b), we will need more code in AArch64BranchTargets.cpp / X86IndirectBranchTracking.cpp . Differential Revision: https://reviews.llvm.org/D73070
2020-01-20 23:57:11 +01:00
; CHECK-NEXT: .Lfunc_begin0:
; CHECK: // %bb.0:
[AsmPrinter] Don't emit __patchable_function_entries entry if "patchable-function-entry"="0" Add improve tests
2020-01-21 00:52:38 +01:00
; CHECK-NEXT: hint #34
Add function attribute "patchable-function-prefix" to support -fpatchable-function-entry=N,M where M>0 Similar to the function attribute `prefix` (prefix data), "patchable-function-prefix" inserts data (M NOPs) before the function entry label. -fpatchable-function-entry=2,1 (1 NOP before entry, 1 NOP after entry) will look like: ``` .type foo,@function .Ltmp0: # @foo nop foo: .Lfunc_begin0: # optional `bti c` (AArch64 Branch Target Identification) or # `endbr64` (Intel Indirect Branch Tracking) nop .section __patchable_function_entries,"awo",@progbits,get,unique,0 .p2align 3 .quad .Ltmp0 ``` -fpatchable-function-entry=N,0 + -mbranch-protection=bti/-fcf-protection=branch has two reasonable placements (https://gcc.gnu.org/ml/gcc-patches/2020-01/msg01185.html): ``` (a) (b) func: func: .Ltmp0: bti c bti c .Ltmp0: nop nop ``` (a) needs no additional code. If the consensus is to go for (b), we will need more code in AArch64BranchTargets.cpp / X86IndirectBranchTracking.cpp . Differential Revision: https://reviews.llvm.org/D73070
2020-01-20 23:57:11 +01:00
; CHECK-NEXT: ret
; CHECK-NOT: .section __patchable_function_entries
ret void
[CodeGen] Move fentry-insert, xray-instrumentation and patchable-function before addPreEmitPass() This intention is to move patchable-function before aarch64-branch-targets (configured in AArch64PassConfig::addPreEmitPass) so that we emit BTI before NOPs (see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92424). This also allows addPreEmitPass() passes to know the precise instruction sizes if they want. Tried x86-64 Debug/Release builds of ccls with -fxray-instrument -fxray-instruction-threshold=1. No output difference with this commit and the previous commit.
2020-01-19 06:44:06 +01:00
}
Add function attribute "patchable-function-prefix" to support -fpatchable-function-entry=N,M where M>0 Similar to the function attribute `prefix` (prefix data), "patchable-function-prefix" inserts data (M NOPs) before the function entry label. -fpatchable-function-entry=2,1 (1 NOP before entry, 1 NOP after entry) will look like: ``` .type foo,@function .Ltmp0: # @foo nop foo: .Lfunc_begin0: # optional `bti c` (AArch64 Branch Target Identification) or # `endbr64` (Intel Indirect Branch Tracking) nop .section __patchable_function_entries,"awo",@progbits,get,unique,0 .p2align 3 .quad .Ltmp0 ``` -fpatchable-function-entry=N,0 + -mbranch-protection=bti/-fcf-protection=branch has two reasonable placements (https://gcc.gnu.org/ml/gcc-patches/2020-01/msg01185.html): ``` (a) (b) func: func: .Ltmp0: bti c bti c .Ltmp0: nop nop ``` (a) needs no additional code. If the consensus is to go for (b), we will need more code in AArch64BranchTargets.cpp / X86IndirectBranchTracking.cpp . Differential Revision: https://reviews.llvm.org/D73070
2020-01-20 23:57:11 +01:00
;; -fpatchable-function-entry=1 -mbranch-protection=bti
[AArch64] -fpatchable-function-entry=N,0: place patch label after BTI Summary: For -fpatchable-function-entry=N,0 -mbranch-protection=bti, after 9a24488cb67a90f889529987275c5e411ce01dda, we place the NOP sled after the initial BTI. ``` .Lfunc_begin0: bti c nop nop .section __patchable_function_entries,"awo",@progbits,f,unique,0 .p2align 3 .xword .Lfunc_begin0 ``` This patch adds a label after the initial BTI and changes the __patchable_function_entries entry to reference the label: ``` .Lfunc_begin0: bti c .Lpatch0: nop nop .section __patchable_function_entries,"awo",@progbits,f,unique,0 .p2align 3 .xword .Lpatch0 ``` This placement is compatible with the resolution in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92424 . A local linkage function whose address is not taken does not need a BTI. Placing the patch label after BTI has the advantage that code does not need to differentiate whether the function has an initial BTI. Reviewers: mrutland, nickdesaulniers, nsz, ostannard Subscribers: kristof.beyls, hiraditya, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D73680
2020-01-30 03:00:57 +01:00
;; For M=0, place the label .Lpatch0 after the initial BTI.
[AArch64] PAC/BTI code generation for LLVM generated functions 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
2020-09-25 12:45:22 +02:00
define void @f1() "patchable-function-entry"="1" "branch-target-enforcement"="true" {
[CodeGen] Move fentry-insert, xray-instrumentation and patchable-function before addPreEmitPass() This intention is to move patchable-function before aarch64-branch-targets (configured in AArch64PassConfig::addPreEmitPass) so that we emit BTI before NOPs (see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92424). This also allows addPreEmitPass() passes to know the precise instruction sizes if they want. Tried x86-64 Debug/Release builds of ccls with -fxray-instrument -fxray-instruction-threshold=1. No output difference with this commit and the previous commit.
2020-01-19 06:44:06 +01:00
; CHECK-LABEL: f1:
Add function attribute "patchable-function-prefix" to support -fpatchable-function-entry=N,M where M>0 Similar to the function attribute `prefix` (prefix data), "patchable-function-prefix" inserts data (M NOPs) before the function entry label. -fpatchable-function-entry=2,1 (1 NOP before entry, 1 NOP after entry) will look like: ``` .type foo,@function .Ltmp0: # @foo nop foo: .Lfunc_begin0: # optional `bti c` (AArch64 Branch Target Identification) or # `endbr64` (Intel Indirect Branch Tracking) nop .section __patchable_function_entries,"awo",@progbits,get,unique,0 .p2align 3 .quad .Ltmp0 ``` -fpatchable-function-entry=N,0 + -mbranch-protection=bti/-fcf-protection=branch has two reasonable placements (https://gcc.gnu.org/ml/gcc-patches/2020-01/msg01185.html): ``` (a) (b) func: func: .Ltmp0: bti c bti c .Ltmp0: nop nop ``` (a) needs no additional code. If the consensus is to go for (b), we will need more code in AArch64BranchTargets.cpp / X86IndirectBranchTracking.cpp . Differential Revision: https://reviews.llvm.org/D73070
2020-01-20 23:57:11 +01:00
; CHECK-NEXT: .Lfunc_begin1:
[X86] -fpatchable-function-entry=N,0: place patch label after ENDBR{32,64} Similar to D73680 (AArch64 BTI). A local linkage function whose address is not taken does not need ENDBR32/ENDBR64. Placing the patch label after ENDBR32/ENDBR64 has the advantage that code does not need to differentiate whether the function has an initial ENDBR. Also, add 32-bit tests and test that .cfi_startproc is at the function entry. The line information has a general implementation and is tested by AArch64/patchable-function-entry-empty.mir Reviewed By: nickdesaulniers Differential Revision: https://reviews.llvm.org/D73760
2020-01-31 03:16:09 +01:00
; CHECK-NEXT: .cfi_startproc
; CHECK-NEXT: // %bb.0:
[AArch64] -fpatchable-function-entry=N,0: place patch label after BTI Summary: For -fpatchable-function-entry=N,0 -mbranch-protection=bti, after 9a24488cb67a90f889529987275c5e411ce01dda, we place the NOP sled after the initial BTI. ``` .Lfunc_begin0: bti c nop nop .section __patchable_function_entries,"awo",@progbits,f,unique,0 .p2align 3 .xword .Lfunc_begin0 ``` This patch adds a label after the initial BTI and changes the __patchable_function_entries entry to reference the label: ``` .Lfunc_begin0: bti c .Lpatch0: nop nop .section __patchable_function_entries,"awo",@progbits,f,unique,0 .p2align 3 .xword .Lpatch0 ``` This placement is compatible with the resolution in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92424 . A local linkage function whose address is not taken does not need a BTI. Placing the patch label after BTI has the advantage that code does not need to differentiate whether the function has an initial BTI. Reviewers: mrutland, nickdesaulniers, nsz, ostannard Subscribers: kristof.beyls, hiraditya, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D73680
2020-01-30 03:00:57 +01:00
; CHECK-NEXT: hint #34
; CHECK-NEXT: .Lpatch0:
[CodeGen] Move fentry-insert, xray-instrumentation and patchable-function before addPreEmitPass() This intention is to move patchable-function before aarch64-branch-targets (configured in AArch64PassConfig::addPreEmitPass) so that we emit BTI before NOPs (see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92424). This also allows addPreEmitPass() passes to know the precise instruction sizes if they want. Tried x86-64 Debug/Release builds of ccls with -fxray-instrument -fxray-instruction-threshold=1. No output difference with this commit and the previous commit.
2020-01-19 06:44:06 +01:00
; CHECK-NEXT: nop
Add function attribute "patchable-function-prefix" to support -fpatchable-function-entry=N,M where M>0 Similar to the function attribute `prefix` (prefix data), "patchable-function-prefix" inserts data (M NOPs) before the function entry label. -fpatchable-function-entry=2,1 (1 NOP before entry, 1 NOP after entry) will look like: ``` .type foo,@function .Ltmp0: # @foo nop foo: .Lfunc_begin0: # optional `bti c` (AArch64 Branch Target Identification) or # `endbr64` (Intel Indirect Branch Tracking) nop .section __patchable_function_entries,"awo",@progbits,get,unique,0 .p2align 3 .quad .Ltmp0 ``` -fpatchable-function-entry=N,0 + -mbranch-protection=bti/-fcf-protection=branch has two reasonable placements (https://gcc.gnu.org/ml/gcc-patches/2020-01/msg01185.html): ``` (a) (b) func: func: .Ltmp0: bti c bti c .Ltmp0: nop nop ``` (a) needs no additional code. If the consensus is to go for (b), we will need more code in AArch64BranchTargets.cpp / X86IndirectBranchTracking.cpp . Differential Revision: https://reviews.llvm.org/D73070
2020-01-20 23:57:11 +01:00
; CHECK-NEXT: ret
[AsmPrinter] Omit unique ID for __patchable_function_entries sections Follow-up for D74006. When the integrated assembler is used, we use SHF_LINK_ORDER. The linked-to symbol is part of ELFSectionKey, thus we can omit the unique ID.
2020-02-15 05:35:04 +01:00
; CHECK: .section __patchable_function_entries,"awo",@progbits,f1{{$}}
Add function attribute "patchable-function-prefix" to support -fpatchable-function-entry=N,M where M>0 Similar to the function attribute `prefix` (prefix data), "patchable-function-prefix" inserts data (M NOPs) before the function entry label. -fpatchable-function-entry=2,1 (1 NOP before entry, 1 NOP after entry) will look like: ``` .type foo,@function .Ltmp0: # @foo nop foo: .Lfunc_begin0: # optional `bti c` (AArch64 Branch Target Identification) or # `endbr64` (Intel Indirect Branch Tracking) nop .section __patchable_function_entries,"awo",@progbits,get,unique,0 .p2align 3 .quad .Ltmp0 ``` -fpatchable-function-entry=N,0 + -mbranch-protection=bti/-fcf-protection=branch has two reasonable placements (https://gcc.gnu.org/ml/gcc-patches/2020-01/msg01185.html): ``` (a) (b) func: func: .Ltmp0: bti c bti c .Ltmp0: nop nop ``` (a) needs no additional code. If the consensus is to go for (b), we will need more code in AArch64BranchTargets.cpp / X86IndirectBranchTracking.cpp . Differential Revision: https://reviews.llvm.org/D73070
2020-01-20 23:57:11 +01:00
; CHECK-NEXT: .p2align 3
[AArch64] -fpatchable-function-entry=N,0: place patch label after BTI Summary: For -fpatchable-function-entry=N,0 -mbranch-protection=bti, after 9a24488cb67a90f889529987275c5e411ce01dda, we place the NOP sled after the initial BTI. ``` .Lfunc_begin0: bti c nop nop .section __patchable_function_entries,"awo",@progbits,f,unique,0 .p2align 3 .xword .Lfunc_begin0 ``` This patch adds a label after the initial BTI and changes the __patchable_function_entries entry to reference the label: ``` .Lfunc_begin0: bti c .Lpatch0: nop nop .section __patchable_function_entries,"awo",@progbits,f,unique,0 .p2align 3 .xword .Lpatch0 ``` This placement is compatible with the resolution in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92424 . A local linkage function whose address is not taken does not need a BTI. Placing the patch label after BTI has the advantage that code does not need to differentiate whether the function has an initial BTI. Reviewers: mrutland, nickdesaulniers, nsz, ostannard Subscribers: kristof.beyls, hiraditya, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D73680
2020-01-30 03:00:57 +01:00
; CHECK-NEXT: .xword .Lpatch0
Add function attribute "patchable-function-prefix" to support -fpatchable-function-entry=N,M where M>0 Similar to the function attribute `prefix` (prefix data), "patchable-function-prefix" inserts data (M NOPs) before the function entry label. -fpatchable-function-entry=2,1 (1 NOP before entry, 1 NOP after entry) will look like: ``` .type foo,@function .Ltmp0: # @foo nop foo: .Lfunc_begin0: # optional `bti c` (AArch64 Branch Target Identification) or # `endbr64` (Intel Indirect Branch Tracking) nop .section __patchable_function_entries,"awo",@progbits,get,unique,0 .p2align 3 .quad .Ltmp0 ``` -fpatchable-function-entry=N,0 + -mbranch-protection=bti/-fcf-protection=branch has two reasonable placements (https://gcc.gnu.org/ml/gcc-patches/2020-01/msg01185.html): ``` (a) (b) func: func: .Ltmp0: bti c bti c .Ltmp0: nop nop ``` (a) needs no additional code. If the consensus is to go for (b), we will need more code in AArch64BranchTargets.cpp / X86IndirectBranchTracking.cpp . Differential Revision: https://reviews.llvm.org/D73070
2020-01-20 23:57:11 +01:00
ret void
}
;; -fpatchable-function-entry=2,1 -mbranch-protection=bti
[AArch64] PAC/BTI code generation for LLVM generated functions 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
2020-09-25 12:45:22 +02:00
define void @f2_1() "patchable-function-entry"="1" "patchable-function-prefix"="1" "branch-target-enforcement"="true" {
Add function attribute "patchable-function-prefix" to support -fpatchable-function-entry=N,M where M>0 Similar to the function attribute `prefix` (prefix data), "patchable-function-prefix" inserts data (M NOPs) before the function entry label. -fpatchable-function-entry=2,1 (1 NOP before entry, 1 NOP after entry) will look like: ``` .type foo,@function .Ltmp0: # @foo nop foo: .Lfunc_begin0: # optional `bti c` (AArch64 Branch Target Identification) or # `endbr64` (Intel Indirect Branch Tracking) nop .section __patchable_function_entries,"awo",@progbits,get,unique,0 .p2align 3 .quad .Ltmp0 ``` -fpatchable-function-entry=N,0 + -mbranch-protection=bti/-fcf-protection=branch has two reasonable placements (https://gcc.gnu.org/ml/gcc-patches/2020-01/msg01185.html): ``` (a) (b) func: func: .Ltmp0: bti c bti c .Ltmp0: nop nop ``` (a) needs no additional code. If the consensus is to go for (b), we will need more code in AArch64BranchTargets.cpp / X86IndirectBranchTracking.cpp . Differential Revision: https://reviews.llvm.org/D73070
2020-01-20 23:57:11 +01:00
; CHECK-LABEL: .type f2_1,@function
; CHECK-NEXT: .Ltmp0:
; CHECK-NEXT: nop
; CHECK-NEXT: f2_1:
; CHECK-NEXT: .Lfunc_begin2:
[X86] -fpatchable-function-entry=N,0: place patch label after ENDBR{32,64} Similar to D73680 (AArch64 BTI). A local linkage function whose address is not taken does not need ENDBR32/ENDBR64. Placing the patch label after ENDBR32/ENDBR64 has the advantage that code does not need to differentiate whether the function has an initial ENDBR. Also, add 32-bit tests and test that .cfi_startproc is at the function entry. The line information has a general implementation and is tested by AArch64/patchable-function-entry-empty.mir Reviewed By: nickdesaulniers Differential Revision: https://reviews.llvm.org/D73760
2020-01-31 03:16:09 +01:00
; CHECK-NEXT: .cfi_startproc
; CHECK-NEXT: // %bb.0:
Add function attribute "patchable-function-prefix" to support -fpatchable-function-entry=N,M where M>0 Similar to the function attribute `prefix` (prefix data), "patchable-function-prefix" inserts data (M NOPs) before the function entry label. -fpatchable-function-entry=2,1 (1 NOP before entry, 1 NOP after entry) will look like: ``` .type foo,@function .Ltmp0: # @foo nop foo: .Lfunc_begin0: # optional `bti c` (AArch64 Branch Target Identification) or # `endbr64` (Intel Indirect Branch Tracking) nop .section __patchable_function_entries,"awo",@progbits,get,unique,0 .p2align 3 .quad .Ltmp0 ``` -fpatchable-function-entry=N,0 + -mbranch-protection=bti/-fcf-protection=branch has two reasonable placements (https://gcc.gnu.org/ml/gcc-patches/2020-01/msg01185.html): ``` (a) (b) func: func: .Ltmp0: bti c bti c .Ltmp0: nop nop ``` (a) needs no additional code. If the consensus is to go for (b), we will need more code in AArch64BranchTargets.cpp / X86IndirectBranchTracking.cpp . Differential Revision: https://reviews.llvm.org/D73070
2020-01-20 23:57:11 +01:00
; CHECK-NEXT: hint #34
; CHECK-NEXT: nop
; CHECK-NEXT: ret
; CHECK: .Lfunc_end2:
; CHECK-NEXT: .size f2_1, .Lfunc_end2-f2_1
[AsmPrinter] Omit unique ID for __patchable_function_entries sections Follow-up for D74006. When the integrated assembler is used, we use SHF_LINK_ORDER. The linked-to symbol is part of ELFSectionKey, thus we can omit the unique ID.
2020-02-15 05:35:04 +01:00
; CHECK: .section __patchable_function_entries,"awo",@progbits,f2_1{{$}}
Add function attribute "patchable-function-prefix" to support -fpatchable-function-entry=N,M where M>0 Similar to the function attribute `prefix` (prefix data), "patchable-function-prefix" inserts data (M NOPs) before the function entry label. -fpatchable-function-entry=2,1 (1 NOP before entry, 1 NOP after entry) will look like: ``` .type foo,@function .Ltmp0: # @foo nop foo: .Lfunc_begin0: # optional `bti c` (AArch64 Branch Target Identification) or # `endbr64` (Intel Indirect Branch Tracking) nop .section __patchable_function_entries,"awo",@progbits,get,unique,0 .p2align 3 .quad .Ltmp0 ``` -fpatchable-function-entry=N,0 + -mbranch-protection=bti/-fcf-protection=branch has two reasonable placements (https://gcc.gnu.org/ml/gcc-patches/2020-01/msg01185.html): ``` (a) (b) func: func: .Ltmp0: bti c bti c .Ltmp0: nop nop ``` (a) needs no additional code. If the consensus is to go for (b), we will need more code in AArch64BranchTargets.cpp / X86IndirectBranchTracking.cpp . Differential Revision: https://reviews.llvm.org/D73070
2020-01-20 23:57:11 +01:00
; CHECK-NEXT: .p2align 3
; CHECK-NEXT: .xword .Ltmp0
ret void
[CodeGen] Move fentry-insert, xray-instrumentation and patchable-function before addPreEmitPass() This intention is to move patchable-function before aarch64-branch-targets (configured in AArch64PassConfig::addPreEmitPass) so that we emit BTI before NOPs (see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92424). This also allows addPreEmitPass() passes to know the precise instruction sizes if they want. Tried x86-64 Debug/Release builds of ccls with -fxray-instrument -fxray-instruction-threshold=1. No output difference with this commit and the previous commit.
2020-01-19 06:44:06 +01:00
}
[AArch64] -fpatchable-function-entry=N,0: place patch label after BTI Summary: For -fpatchable-function-entry=N,0 -mbranch-protection=bti, after 9a24488cb67a90f889529987275c5e411ce01dda, we place the NOP sled after the initial BTI. ``` .Lfunc_begin0: bti c nop nop .section __patchable_function_entries,"awo",@progbits,f,unique,0 .p2align 3 .xword .Lfunc_begin0 ``` This patch adds a label after the initial BTI and changes the __patchable_function_entries entry to reference the label: ``` .Lfunc_begin0: bti c .Lpatch0: nop nop .section __patchable_function_entries,"awo",@progbits,f,unique,0 .p2align 3 .xword .Lpatch0 ``` This placement is compatible with the resolution in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92424 . A local linkage function whose address is not taken does not need a BTI. Placing the patch label after BTI has the advantage that code does not need to differentiate whether the function has an initial BTI. Reviewers: mrutland, nickdesaulniers, nsz, ostannard Subscribers: kristof.beyls, hiraditya, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D73680
2020-01-30 03:00:57 +01:00
;; -fpatchable-function-entry=1 -mbranch-protection=bti
[AArch64][v8.5A] Add BTI to all function starts The existing BTI placement pass avoids inserting "BTI c" when the function has local linkage and is only directly called. However, even in this case, there is a (small) chance that the linker later adds a hunk with an indirect call to the function, e.g. if the function is placed in a separate section and moved far away from its callers. Make sure to add BTI for these functions too. Differential Revision: https://reviews.llvm.org/D99417
2021-03-24 12:03:05 +01:00
;; We add BTI c even when the function has internal linkage
[AArch64] PAC/BTI code generation for LLVM generated functions 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
2020-09-25 12:45:22 +02:00
define internal void @f1i(i64 %v) "patchable-function-entry"="1" "branch-target-enforcement"="true" {
[AArch64] -fpatchable-function-entry=N,0: place patch label after BTI Summary: For -fpatchable-function-entry=N,0 -mbranch-protection=bti, after 9a24488cb67a90f889529987275c5e411ce01dda, we place the NOP sled after the initial BTI. ``` .Lfunc_begin0: bti c nop nop .section __patchable_function_entries,"awo",@progbits,f,unique,0 .p2align 3 .xword .Lfunc_begin0 ``` This patch adds a label after the initial BTI and changes the __patchable_function_entries entry to reference the label: ``` .Lfunc_begin0: bti c .Lpatch0: nop nop .section __patchable_function_entries,"awo",@progbits,f,unique,0 .p2align 3 .xword .Lpatch0 ``` This placement is compatible with the resolution in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92424 . A local linkage function whose address is not taken does not need a BTI. Placing the patch label after BTI has the advantage that code does not need to differentiate whether the function has an initial BTI. Reviewers: mrutland, nickdesaulniers, nsz, ostannard Subscribers: kristof.beyls, hiraditya, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D73680
2020-01-30 03:00:57 +01:00
; CHECK-LABEL: f1i:
; CHECK-NEXT: .Lfunc_begin3:
; CHECK: // %bb.0:
[AArch64][v8.5A] Add BTI to all function starts The existing BTI placement pass avoids inserting "BTI c" when the function has local linkage and is only directly called. However, even in this case, there is a (small) chance that the linker later adds a hunk with an indirect call to the function, e.g. if the function is placed in a separate section and moved far away from its callers. Make sure to add BTI for these functions too. Differential Revision: https://reviews.llvm.org/D99417
2021-03-24 12:03:05 +01:00
; CHECK-NEXT: hint #34
; CHECK-NEXT: .Lpatch1:
[AArch64] -fpatchable-function-entry=N,0: place patch label after BTI Summary: For -fpatchable-function-entry=N,0 -mbranch-protection=bti, after 9a24488cb67a90f889529987275c5e411ce01dda, we place the NOP sled after the initial BTI. ``` .Lfunc_begin0: bti c nop nop .section __patchable_function_entries,"awo",@progbits,f,unique,0 .p2align 3 .xword .Lfunc_begin0 ``` This patch adds a label after the initial BTI and changes the __patchable_function_entries entry to reference the label: ``` .Lfunc_begin0: bti c .Lpatch0: nop nop .section __patchable_function_entries,"awo",@progbits,f,unique,0 .p2align 3 .xword .Lpatch0 ``` This placement is compatible with the resolution in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92424 . A local linkage function whose address is not taken does not need a BTI. Placing the patch label after BTI has the advantage that code does not need to differentiate whether the function has an initial BTI. Reviewers: mrutland, nickdesaulniers, nsz, ostannard Subscribers: kristof.beyls, hiraditya, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D73680
2020-01-30 03:00:57 +01:00
; CHECK-NEXT: nop
;; Other basic blocks have BTI, but they don't affect our decision to not create .Lpatch0
; CHECK: .LBB{{.+}} // %sw.bb1
; CHECK-NEXT: hint #36
[AsmPrinter] Omit unique ID for __patchable_function_entries sections Follow-up for D74006. When the integrated assembler is used, we use SHF_LINK_ORDER. The linked-to symbol is part of ELFSectionKey, thus we can omit the unique ID.
2020-02-15 05:35:04 +01:00
; CHECK: .section __patchable_function_entries,"awo",@progbits,f1i{{$}}
[AArch64] -fpatchable-function-entry=N,0: place patch label after BTI Summary: For -fpatchable-function-entry=N,0 -mbranch-protection=bti, after 9a24488cb67a90f889529987275c5e411ce01dda, we place the NOP sled after the initial BTI. ``` .Lfunc_begin0: bti c nop nop .section __patchable_function_entries,"awo",@progbits,f,unique,0 .p2align 3 .xword .Lfunc_begin0 ``` This patch adds a label after the initial BTI and changes the __patchable_function_entries entry to reference the label: ``` .Lfunc_begin0: bti c .Lpatch0: nop nop .section __patchable_function_entries,"awo",@progbits,f,unique,0 .p2align 3 .xword .Lpatch0 ``` This placement is compatible with the resolution in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92424 . A local linkage function whose address is not taken does not need a BTI. Placing the patch label after BTI has the advantage that code does not need to differentiate whether the function has an initial BTI. Reviewers: mrutland, nickdesaulniers, nsz, ostannard Subscribers: kristof.beyls, hiraditya, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D73680
2020-01-30 03:00:57 +01:00
; CHECK-NEXT: .p2align 3
[AArch64][v8.5A] Add BTI to all function starts The existing BTI placement pass avoids inserting "BTI c" when the function has local linkage and is only directly called. However, even in this case, there is a (small) chance that the linker later adds a hunk with an indirect call to the function, e.g. if the function is placed in a separate section and moved far away from its callers. Make sure to add BTI for these functions too. Differential Revision: https://reviews.llvm.org/D99417
2021-03-24 12:03:05 +01:00
; CHECK-NEXT: .xword .Lpatch1
[AArch64] -fpatchable-function-entry=N,0: place patch label after BTI Summary: For -fpatchable-function-entry=N,0 -mbranch-protection=bti, after 9a24488cb67a90f889529987275c5e411ce01dda, we place the NOP sled after the initial BTI. ``` .Lfunc_begin0: bti c nop nop .section __patchable_function_entries,"awo",@progbits,f,unique,0 .p2align 3 .xword .Lfunc_begin0 ``` This patch adds a label after the initial BTI and changes the __patchable_function_entries entry to reference the label: ``` .Lfunc_begin0: bti c .Lpatch0: nop nop .section __patchable_function_entries,"awo",@progbits,f,unique,0 .p2align 3 .xword .Lpatch0 ``` This placement is compatible with the resolution in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92424 . A local linkage function whose address is not taken does not need a BTI. Placing the patch label after BTI has the advantage that code does not need to differentiate whether the function has an initial BTI. Reviewers: mrutland, nickdesaulniers, nsz, ostannard Subscribers: kristof.beyls, hiraditya, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D73680
2020-01-30 03:00:57 +01:00
entry:
switch i64 %v, label %sw.bb0 [
i64 1, label %sw.bb1
i64 2, label %sw.bb2
i64 3, label %sw.bb3
i64 4, label %sw.bb4
]
sw.bb0:
call void asm sideeffect "", ""()
ret void
sw.bb1:
call void asm sideeffect "", ""()
ret void
sw.bb2:
call void asm sideeffect "", ""()
ret void
sw.bb3:
call void asm sideeffect "", ""()
ret void
sw.bb4:
call void asm sideeffect "", ""()
ret void
}
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