Merge branch 'llvm:main' into cray-ptr-size

Author: eugeneepshteyn

.ci/generate_test_report_lib.py

@@ -92,7 +92,9 @@ def plural(num_tests):
             ]
         )
     elif failures:
-        report.extend(["", "## Failed Tests", "(click on a test name to see its output)"])
+        report.extend(
+            ["", "## Failed Tests", "(click on a test name to see its output)"]
+        )
 
         for testsuite_name, failures in failures.items():
             report.extend(["", f"### {testsuite_name}"])

.ci/metrics/metrics.py

@@ -67,6 +67,7 @@
 # remain small.
 BUILDKITE_GRAPHQL_BUILDS_PER_PAGE = 50
 
+
 @dataclass
 class JobMetrics:
     job_name: str
@@ -77,6 +78,7 @@ class JobMetrics:
     workflow_id: int
     workflow_name: str
 
+
 @dataclass
 class GaugeMetric:
     name: str
@@ -258,6 +260,7 @@ def buildkite_get_metrics(
 
     return output, incomplete_now
 
+
 def github_get_metrics(
     github_repo: github.Repository, last_workflows_seen_as_completed: set[int]
 ) -> tuple[list[JobMetrics], int]:

bolt/include/bolt/Core/MCPlusBuilder.h

@@ -49,6 +49,7 @@ class MCSymbol;
 class raw_ostream;
 
 namespace bolt {
+class BinaryBasicBlock;
 class BinaryFunction;
 
 /// Different types of indirect branches encountered during disassembly.
@@ -572,6 +573,11 @@ class MCPlusBuilder {
     return false;
   }
 
+  virtual MCPhysReg getSignedReg(const MCInst &Inst) const {
+    llvm_unreachable("not implemented");
+    return getNoRegister();
+  }
+
   virtual ErrorOr<MCPhysReg> getRegUsedAsRetDest(const MCInst &Inst) const {
     llvm_unreachable("not implemented");
     return getNoRegister();
@@ -622,6 +628,54 @@ class MCPlusBuilder {
     return std::make_pair(getNoRegister(), getNoRegister());
   }
 
+  /// Analyzes if a pointer is checked to be authenticated successfully
+  /// by the end of the basic block.
+  ///
+  /// It is possible for pointer authentication instructions not to terminate
+  /// the program abnormally on authentication failure and return some invalid
+  /// pointer instead (like it is done on AArch64 when FEAT_FPAC is not
+  /// implemented). This might be enough to crash on invalid memory access when
+  /// the pointer is later used as the destination of a load, store, or branch
+  /// instruction. On the other hand, when the pointer is not used right away,
+  /// it may be important for the compiler to check the address explicitly not
+  /// to introduce a signing or authentication oracle.
+  ///
+  /// This function is intended to detect a complex, multi-instruction pointer-
+  /// checking sequence spanning a contiguous range of instructions at the end
+  /// of the basic block (as these sequences are expected to end with a
+  /// conditional branch - this is how they are implemented on AArch64 by LLVM).
+  /// If a (Reg, FirstInst) pair is returned and before execution of FirstInst
+  /// Reg was last written to by an authentication instruction, then it is known
+  /// that in any successor of BB either
+  /// * the authentication instruction that last wrote to Reg succeeded, or
+  /// * the program is terminated abnormally without introducing any signing
+  ///   or authentication oracles
+  ///
+  /// Note that this function is not expected to repeat the results returned
+  /// by getAuthCheckedReg(Inst, MayOverwrite) function below.
+  virtual std::optional<std::pair<MCPhysReg, MCInst *>>
+  getAuthCheckedReg(BinaryBasicBlock &BB) const {
+    llvm_unreachable("not implemented");
+    return std::nullopt;
+  }
+
+  /// Returns the register that is checked to be authenticated successfully.
+  ///
+  /// If the returned register was last written to by an authentication
+  /// instruction and that authentication failed, then the program is known
+  /// to be terminated abnormally as a result of execution of Inst.
+  ///
+  /// Additionally, if MayOverwrite is false, it is known that the authenticated
+  /// pointer is not clobbered by Inst itself.
+  ///
+  /// Use this function for simple, single-instruction patterns instead of
+  /// its getAuthCheckedReg(BB) counterpart.
+  virtual MCPhysReg getAuthCheckedReg(const MCInst &Inst,
+                                      bool MayOverwrite) const {
+    llvm_unreachable("not implemented");
+    return getNoRegister();
+  }
+
   virtual bool isTerminator(const MCInst &Inst) const;
 
   virtual bool isNoop(const MCInst &Inst) const {

bolt/include/bolt/Passes/PAuthGadgetScanner.h

@@ -12,7 +12,6 @@
 #include "bolt/Core/BinaryContext.h"
 #include "bolt/Core/BinaryFunction.h"
 #include "bolt/Passes/BinaryPasses.h"
-#include "llvm/ADT/SmallSet.h"
 #include "llvm/Support/raw_ostream.h"
 #include <memory>
 
@@ -197,9 +196,6 @@ raw_ostream &operator<<(raw_ostream &OS, const MCInstReference &);
 
 namespace PAuthGadgetScanner {
 
-class SrcSafetyAnalysis;
-struct SrcState;
-
 /// Description of a gadget kind that can be detected. Intended to be
 /// statically allocated to be attached to reports by reference.
 class GadgetKind {
@@ -208,7 +204,7 @@ class GadgetKind {
 public:
   GadgetKind(const char *Description) : Description(Description) {}
 
-  const StringRef getDescription() const { return Description; }
+  StringRef getDescription() const { return Description; }
 };
 
 /// Base report located at some instruction, without any additional information.
@@ -223,8 +219,8 @@ struct Report {
 
   // The two methods below are called by Analysis::computeDetailedInfo when
   // iterating over the reports.
-  virtual const ArrayRef<MCPhysReg> getAffectedRegisters() const { return {}; }
-  virtual void setOverwritingInstrs(const ArrayRef<MCInstReference> Instrs) {}
+  virtual ArrayRef<MCPhysReg> getAffectedRegisters() const { return {}; }
+  virtual void setOverwritingInstrs(ArrayRef<MCInstReference> Instrs) {}
 
   void printBasicInfo(raw_ostream &OS, const BinaryContext &BC,
                       StringRef IssueKind) const;
@@ -247,19 +243,19 @@ struct GadgetReport : public Report {
 
   void generateReport(raw_ostream &OS, const BinaryContext &BC) const override;
 
-  const ArrayRef<MCPhysReg> getAffectedRegisters() const override {
+  ArrayRef<MCPhysReg> getAffectedRegisters() const override {
     return AffectedRegisters;
   }
 
-  void setOverwritingInstrs(const ArrayRef<MCInstReference> Instrs) override {
+  void setOverwritingInstrs(ArrayRef<MCInstReference> Instrs) override {
     OverwritingInstrs.assign(Instrs.begin(), Instrs.end());
   }
 };
 
 /// Report with a free-form message attached.
 struct GenericReport : public Report {
   std::string Text;
-  GenericReport(MCInstReference Location, const std::string &Text)
+  GenericReport(MCInstReference Location, StringRef Text)
       : Report(Location), Text(Text) {}
   virtual void generateReport(raw_ostream &OS,
                               const BinaryContext &BC) const override;

bolt/lib/Core/BinaryFunction.cpp

@@ -1783,10 +1783,22 @@ bool BinaryFunction::scanExternalRefs() {
     // On AArch64, we use instruction patches for fixing references. We make an
     // exception for branch instructions since they require optional
     // relocations.
-    if (BC.isAArch64() && !BranchTargetSymbol) {
-      LLVM_DEBUG(BC.printInstruction(dbgs(), Instruction, AbsoluteInstrAddr));
-      InstructionPatches.push_back({AbsoluteInstrAddr, Instruction});
-      continue;
+    if (BC.isAArch64()) {
+      if (!BranchTargetSymbol) {
+        LLVM_DEBUG(BC.printInstruction(dbgs(), Instruction, AbsoluteInstrAddr));
+        InstructionPatches.push_back({AbsoluteInstrAddr, Instruction});
+        continue;
+      }
+
+      // Conditional tail calls require new relocation types that are currently
+      // not supported. https://github.com/llvm/llvm-project/issues/138264
+      if (BC.MIB->isConditionalBranch(Instruction)) {
+        if (BinaryFunction *TargetBF =
+                BC.getFunctionForSymbol(BranchTargetSymbol)) {
+          TargetBF->setNeedsPatch(true);
+          continue;
+        }
+      }
     }
 
     // Emit the instruction using temp emitter and generate relocations.