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[BOLT][AArch64] Do not crash on authenticated branch instructions #129898

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Merged
atrosinenko merged 2 commits into from
Mar 17, 2025
Merged

[BOLT][AArch64] Do not crash on authenticated branch instructions #129898

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7a97754
[BOLT][AArch64] Do not crash on authenticated branch instructions
atrosinenko Mar 4, 2025
f3b42ad
Use switch-case instead of or-ed comparisons
atrosinenko Mar 10, 2025
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12 changes: 12 additions & 0 deletions bolt/lib/Target/AArch64/AArch64MCPlusBuilder.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -547,6 +547,13 @@ class AArch64MCPlusBuilder : public MCPlusBuilder {
return false;
}

bool isBRA(const MCInst &Inst) const {
return (Inst.getOpcode() == AArch64::BRAA ||
Inst.getOpcode() == AArch64::BRAB ||
Inst.getOpcode() == AArch64::BRAAZ ||
Inst.getOpcode() == AArch64::BRABZ);
}

bool mayLoad(const MCInst &Inst) const override {
return isLDRB(Inst) || isLDRH(Inst) || isLDRW(Inst) || isLDRX(Inst) ||
isLDRQ(Inst) || isLDRD(Inst) || isLDRS(Inst);
Expand Down Expand Up @@ -941,6 +948,11 @@ class AArch64MCPlusBuilder : public MCPlusBuilder {
DenseMap<const MCInst *, SmallVector<MCInst *, 4>> &UDChain,
const MCExpr *&JumpTable, int64_t &Offset, int64_t &ScaleValue,
MCInst *&PCRelBase) const {
// The only kind of indirect branches we match is jump table, thus ignore
// authenticating branch instructions early.
if (isBRA(Inst))
return false;

// Expect AArch64 BR
assert(Inst.getOpcode() == AArch64::BR && "Unexpected opcode");

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23 changes: 22 additions & 1 deletion bolt/test/AArch64/test-indirect-branch.s
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Expand Up @@ -5,7 +5,7 @@

// REQUIRES: system-linux, asserts

// RUN: llvm-mc -filetype=obj -triple aarch64-unknown-unknown %s -o %t.o
// RUN: llvm-mc -filetype=obj -triple aarch64-unknown-unknown -mattr=+pauth %s -o %t.o
// RUN: %clang %cflags --target=aarch64-unknown-linux %t.o -o %t.exe -Wl,-q
// RUN: llvm-bolt %t.exe -o %t.bolt --print-cfg --strict --debug-only=mcplus \
// RUN: -v=1 2>&1 | FileCheck %s
Expand Down Expand Up @@ -73,6 +73,27 @@ test2_0:
test2_1:
ret

// Make sure BOLT does not crash trying to disassemble BRA* instructions.
.globl test_braa
.type test_braa, %function
test_braa:
braa x0, x1

.globl test_brab
.type test_brab, %function
test_brab:
brab x0, x1

.globl test_braaz
.type test_braaz, %function
test_braaz:
braaz x0

.globl test_brabz
.type test_brabz, %function
test_brabz:
brabz x0

.section .rodata,"a",@progbits
datatable:
.word test1_0-datatable
Expand Down