release/20.x: [LoongArch] Fix assertion failure for annotate tablejump (#140907) #141193
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@wangleiat What do you think about merging this PR to the release branch? |
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@llvm/pr-subscribers-backend-loongarch Author: None (llvmbot) ChangesBackport 4e186f2 Requested by: @heiher Full diff: https://github.com/llvm/llvm-project/pull/141193.diff 3 Files Affected:
diff --git a/llvm/lib/Target/LoongArch/LoongArchAsmPrinter.cpp b/llvm/lib/Target/LoongArch/LoongArchAsmPrinter.cpp
index 895a8e2646692..9a383f0a79a5c 100644
--- a/llvm/lib/Target/LoongArch/LoongArchAsmPrinter.cpp
+++ b/llvm/lib/Target/LoongArch/LoongArchAsmPrinter.cpp
@@ -265,13 +265,16 @@ void LoongArchAsmPrinter::emitJumpTableInfo() {
assert(TM.getTargetTriple().isOSBinFormatELF());
- unsigned Size = getDataLayout().getPointerSize();
auto *LAFI = MF->getInfo<LoongArchMachineFunctionInfo>();
unsigned EntrySize = LAFI->getJumpInfoSize();
+ auto JTI = MF->getJumpTableInfo();
- if (0 == EntrySize)
+ if (!JTI || 0 == EntrySize)
return;
+ unsigned Size = getDataLayout().getPointerSize();
+ auto JT = JTI->getJumpTables();
+
// Emit an additional section to store the correlation info as pairs of
// addresses, each pair contains the address of a jump instruction (jr) and
// the address of the jump table.
@@ -279,14 +282,15 @@ void LoongArchAsmPrinter::emitJumpTableInfo() {
".discard.tablejump_annotate", ELF::SHT_PROGBITS, 0));
for (unsigned Idx = 0; Idx < EntrySize; ++Idx) {
+ int JTIIdx = LAFI->getJumpInfoJTIIndex(Idx);
+ if (JT[JTIIdx].MBBs.empty())
+ continue;
OutStreamer->emitValue(
MCSymbolRefExpr::create(LAFI->getJumpInfoJrMI(Idx)->getPreInstrSymbol(),
OutContext),
Size);
OutStreamer->emitValue(
- MCSymbolRefExpr::create(
- GetJTISymbol(LAFI->getJumpInfoJTIMO(Idx)->getIndex()), OutContext),
- Size);
+ MCSymbolRefExpr::create(GetJTISymbol(JTIIdx), OutContext), Size);
}
}
diff --git a/llvm/lib/Target/LoongArch/LoongArchExpandPseudoInsts.cpp b/llvm/lib/Target/LoongArch/LoongArchExpandPseudoInsts.cpp
index c2d73a260b1c1..2107908be34ca 100644
--- a/llvm/lib/Target/LoongArch/LoongArchExpandPseudoInsts.cpp
+++ b/llvm/lib/Target/LoongArch/LoongArchExpandPseudoInsts.cpp
@@ -638,7 +638,8 @@ void LoongArchPreRAExpandPseudo::annotateTableJump(
if (MO.isJTI()) {
MBBI->setPreInstrSymbol(
*MF, MF->getContext().createNamedTempSymbol("jrtb_"));
- MF->getInfo<LoongArchMachineFunctionInfo>()->setJumpInfo(&*MBBI, &MO);
+ MF->getInfo<LoongArchMachineFunctionInfo>()->setJumpInfo(
+ &*MBBI, MO.getIndex());
IsFound = true;
return;
}
diff --git a/llvm/lib/Target/LoongArch/LoongArchMachineFunctionInfo.h b/llvm/lib/Target/LoongArch/LoongArchMachineFunctionInfo.h
index daa47c4dc7e32..904985c189dba 100644
--- a/llvm/lib/Target/LoongArch/LoongArchMachineFunctionInfo.h
+++ b/llvm/lib/Target/LoongArch/LoongArchMachineFunctionInfo.h
@@ -41,7 +41,7 @@ class LoongArchMachineFunctionInfo : public MachineFunctionInfo {
/// Pairs of `jr` instructions and corresponding JTI operands, used for the
/// `annotate-tablejump` option.
- SmallVector<std::pair<MachineInstr *, MachineOperand *>, 4> JumpInfos;
+ SmallVector<std::pair<MachineInstr *, int>, 4> JumpInfos;
public:
LoongArchMachineFunctionInfo(const Function &F,
@@ -76,14 +76,12 @@ class LoongArchMachineFunctionInfo : public MachineFunctionInfo {
return is_contained(SExt32Registers, Reg);
}
- void setJumpInfo(MachineInstr *JrMI, MachineOperand *JTIMO) {
- JumpInfos.push_back(std::make_pair(JrMI, JTIMO));
+ void setJumpInfo(MachineInstr *JrMI, int JTIIdx) {
+ JumpInfos.push_back(std::make_pair(JrMI, JTIIdx));
}
unsigned getJumpInfoSize() { return JumpInfos.size(); }
MachineInstr *getJumpInfoJrMI(unsigned Idx) { return JumpInfos[Idx].first; }
- MachineOperand *getJumpInfoJTIMO(unsigned Idx) {
- return JumpInfos[Idx].second;
- }
+ int getJumpInfoJTIIndex(unsigned Idx) { return JumpInfos[Idx].second; }
};
} // end namespace llvm
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github-project-automation
bot
moved this from Needs Triage
to Needs Merge
in LLVM Release Status
Fix a use-after-free issue related to annotateTableJump in the LoongArch target. Previously, `LoongArchPreRAExpandPseudo::annotateTableJump()` recorded a reference to a MachineOperand representing a jump table index. However, later optimizations such as the `BranchFolder` pass may delete the instruction containing this operand, leaving a dangling reference. This led to an assertion failure in `LoongArchAsmPrinter::emitJumpTableInfo()` when trying to access a freed MachineOperand via `getIndex()`. The fix avoids holding a reference to the MachineOperand. Instead, we extract and store the jump table index at the time of annotation. During `emitJumpTableInfo()`, we verify whether the recorded index still exists in the MachineFunction's jump table. If not, we skip emission for that entry. Fixes llvm#140904 (cherry picked from commit 4e186f2)
github-project-automation
bot
moved this from Needs Merge
to Done
in LLVM Release Status
|
@heiher (or anyone else). If you would like to add a note about this fix in the release notes (completely optional). Please reply to this comment with a one or two sentence description of the fix. When you are done, please add the release:note label to this PR. |
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Backport 4e186f2
Requested by: @heiher