add pre-aggregated external return fall-through

Created using spr 1.3.4

Author: aaupov

.github/new-prs-labeler.yml

@@ -777,6 +777,10 @@ backend:NVPTX:
   - 'llvm/**/*nvptx*/**'
   - 'llvm/**/*NVPTX*/**'
 
+backend:MIPS:
+  - '**/*mips*'
+  - '**/*Mips*'
+
 backend:RISC-V:
   - clang/**/*riscv*
   - clang/**/*RISCV*

.github/workflows/libcxx-restart-preempted-jobs.yaml

@@ -33,7 +33,7 @@ jobs:
         with:
           script: |
             const failure_regex = /Process completed with exit code 1./
-            const preemption_regex = /The runner has received a shutdown signal/
+            const preemption_regex = /(The runner has received a shutdown signal)|(The operation was canceled)/
 
             const wf_run = context.payload.workflow_run
             core.notice(`Running on "${wf_run.display_title}" by @${wf_run.actor.login} (event: ${wf_run.event})\nWorkflow run URL: ${wf_run.html_url}`)

bolt/include/bolt/Passes/PAuthGadgetScanner.h

@@ -199,8 +199,7 @@ namespace PAuthGadgetScanner {
 // to distinguish intermediate and final results at the type level.
 //
 // Here is an overview of issue life-cycle:
-// * an analysis (SrcSafetyAnalysis at now, DstSafetyAnalysis will be added
-//   later to support the detection of authentication oracles) computes register
+// * an analysis (SrcSafetyAnalysis or DstSafetyAnalysis) computes register
 //   state for each instruction in the function.
 // * for each instruction, it is checked whether it is a gadget of some kind,
 //   taking the computed state into account. If a gadget is found, its kind
@@ -273,6 +272,11 @@ class ExtraInfo {
   virtual ~ExtraInfo() {}
 };
 
+/// The set of instructions writing to the affected register in an unsafe
+/// manner.
+///
+/// This is a hint to be printed alongside the report. It should be further
+/// analyzed by the user.
 class ClobberingInfo : public ExtraInfo {
   SmallVector<MCInstReference> ClobberingInstrs;
 
@@ -282,6 +286,20 @@ class ClobberingInfo : public ExtraInfo {
   void print(raw_ostream &OS, const MCInstReference Location) const override;
 };
 
+/// The set of instructions leaking the authenticated pointer before the
+/// result of authentication was checked.
+///
+/// This is a hint to be printed alongside the report. It should be further
+/// analyzed by the user.
+class LeakageInfo : public ExtraInfo {
+  SmallVector<MCInstReference> LeakingInstrs;
+
+public:
+  LeakageInfo(ArrayRef<MCInstReference> Instrs) : LeakingInstrs(Instrs) {}
+
+  void print(raw_ostream &OS, const MCInstReference Location) const override;
+};
+
 /// A brief version of a report that can be further augmented with the details.
 ///
 /// A half-baked report produced on the first run of the analysis. An extra,
@@ -322,6 +340,9 @@ class FunctionAnalysisContext {
   void findUnsafeUses(SmallVector<PartialReport<MCPhysReg>> &Reports);
   void augmentUnsafeUseReports(ArrayRef<PartialReport<MCPhysReg>> Reports);
 
+  void findUnsafeDefs(SmallVector<PartialReport<MCPhysReg>> &Reports);
+  void augmentUnsafeDefReports(ArrayRef<PartialReport<MCPhysReg>> Reports);
+
   /// Process the reports which do not have to be augmented, and remove them
   /// from Reports.
   void handleSimpleReports(SmallVector<PartialReport<MCPhysReg>> &Reports);

bolt/include/bolt/Profile/DataAggregator.h

@@ -99,17 +99,17 @@ class DataAggregator : public DataReader {
     uint64_t Addr;
   };
 
-  /// Container for the unit of branch data.
-  /// Backwards compatible with legacy use for branches and fall-throughs:
-  /// - if \p Branch is FT_ONLY or FT_EXTERNAL_ORIGIN, the trace only
-  ///   contains fall-through data,
-  /// - if \p To is BR_ONLY, the trace only contains branch data.
+  /// Container for the unit of branch data, matching pre-aggregated trace type.
+  /// Backwards compatible with branch and fall-through types:
+  /// - if \p To is < 0, the trace only contains branch data (BR_ONLY),
+  /// - if \p Branch is < 0, the trace only contains fall-through data
+  ///   (FT_ONLY, FT_EXTERNAL_ORIGIN, or FT_EXTERNAL_RETURN).
   struct Trace {
     static constexpr const uint64_t EXTERNAL = 0ULL;
     static constexpr const uint64_t BR_ONLY = -1ULL;
     static constexpr const uint64_t FT_ONLY = -1ULL;
     static constexpr const uint64_t FT_EXTERNAL_ORIGIN = -2ULL;
-    static constexpr const uint64_t BR_EXTERNAL_RETURN = -3ULL;
+    static constexpr const uint64_t FT_EXTERNAL_RETURN = -3ULL;
 
     uint64_t Branch;
     uint64_t From;
@@ -391,7 +391,7 @@ class DataAggregator : public DataReader {
   /// S <start> <count>
   /// [TR] <start> <end> <ft_end> <count>
   /// B <start> <end> <count> <mispred_count>
-  /// [Ff] <start> <end> <count>
+  /// [Ffr] <start> <end> <count>
   ///
   /// where <start>, <end>, <ft_end> have the format [<id>:]<offset>
   ///
@@ -402,6 +402,8 @@ class DataAggregator : public DataReader {
   /// f - an aggregated fall-through with external origin - used to disambiguate
   ///       between a return hitting a basic block head and a regular internal
   ///       jump to the block
+  /// r - an aggregated fall-through originating at an external return, no
+  ///       checks are performed for a fallthrough start
   /// T - an aggregated trace: branch from <start> to <end> with a fall-through
   ///       to <ft_end>
   /// R - an aggregated trace originating at a return
@@ -532,10 +534,12 @@ inline raw_ostream &operator<<(raw_ostream &OS,
                                const DataAggregator::Trace &T) {
   switch (T.Branch) {
   case DataAggregator::Trace::FT_ONLY:
+    break;
   case DataAggregator::Trace::FT_EXTERNAL_ORIGIN:
+    OS << "X:0 -> ";
     break;
-  case DataAggregator::Trace::BR_EXTERNAL_RETURN:
-    OS << "0 -> ";
+  case DataAggregator::Trace::FT_EXTERNAL_RETURN:
+    OS << "X:R -> ";
     break;
   default:
     OS << Twine::utohexstr(T.Branch) << " -> ";