Merge changes I81e73bdd,Ic429735f into main

* changes: Avoid builtin overflow arithmetic implicit_segment_forest: Fix MSVC warning C4146
google · Jan 21, 2025 · cc4b7aa · cc4b7aa
2 parents c78fc82 + e81d243
commit cc4b7aa
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Showing 6 changed files with 10 additions and 21 deletions.
diff --git a/src/trace_processor/containers/implicit_segment_forest.h b/src/trace_processor/containers/implicit_segment_forest.h
@@ -120,7 +120,7 @@ class ImplicitSegmentForest {
   uint32_t size() const { return static_cast<uint32_t>(values_.size() / 2); }
 
  private:
-  static uint32_t Lsp(uint32_t x) { return x & -x; }
+  static uint32_t Lsp(uint32_t x) { return x & ~(x - 1); }
   static uint32_t Msp(uint32_t x) {
     return (1u << (sizeof(x) * 8 - 1)) >> __builtin_clz(x);
   }

diff --git a/src/trace_processor/importers/etm/etm_v4_stream.cc b/src/trace_processor/importers/etm/etm_v4_stream.cc
@@ -71,7 +71,9 @@ base::Status EtmV4Stream::ParseFramedData(uint64_t offset, TraceBlobView data) {
                                    data.data(), &num_bytes_processed));
   PERFETTO_CHECK(keep_going);
   PERFETTO_CHECK(num_bytes_processed == data_block_size);
-  PERFETTO_CHECK(perf_importer::SafeAdd(index_, data_block_size, &index_));
+  PERFETTO_CHECK(index_ <= std::numeric_limits<decltype(index_)>::max() -
+                               data_block_size);
+  index_ += data_block_size;
 
   ASSIGN_OR_RETURN(keep_going, frame_decoder_->TraceDataIn(
                                    OCSD_OP_EOT, index_, 0, nullptr, nullptr));

diff --git a/src/trace_processor/importers/etm/etm_v4_stream_demultiplexer.cc b/src/trace_processor/importers/etm/etm_v4_stream_demultiplexer.cc
@@ -130,15 +130,16 @@ ReadCpuConfig(perf_importer::Reader& reader) {
   }
 
   uint32_t cpu;
-  if (!perf_importer::SafeAdd(cpu_header.cpu, 0, &cpu)) {
+  if (!perf_importer::SafeCast(cpu_header.cpu, &cpu)) {
     return base::ErrStatus("Integer overflow in ETM info header");
   }
 
   uint32_t size;
-  if (!perf_importer::SafeMultiply(cpu_header.trace_parameter_count, 8,
-                                   &size)) {
+  if (cpu_header.trace_parameter_count >
+      std::numeric_limits<uint32_t>::max() / 8) {
     return base::ErrStatus("Integer overflow in ETM info header");
   }
+  size = static_cast<uint32_t>(cpu_header.trace_parameter_count * 8);
 
   TraceBlobView blob;
   if (!reader.ReadBlob(blob, size)) {

diff --git a/src/trace_processor/importers/perf/aux_record.cc b/src/trace_processor/importers/perf/aux_record.cc
@@ -33,8 +33,7 @@ base::Status AuxRecord::Parse(const Record& record) {
     return base::ErrStatus("Failed to parse AUX record");
   }
 
-  uint64_t unused;
-  if (!SafeAdd(offset, size, &unused)) {
+  if (offset > std::numeric_limits<decltype(offset)>::max() - size) {
     return base::ErrStatus("AUX record overflows");
   }
 

diff --git a/src/trace_processor/importers/perf/auxtrace_record.cc b/src/trace_processor/importers/perf/auxtrace_record.cc
@@ -19,7 +19,6 @@
 #include "perfetto/base/status.h"
 #include "src/trace_processor/importers/perf/reader.h"
 #include "src/trace_processor/importers/perf/record.h"
-#include "src/trace_processor/importers/perf/util.h"
 
 namespace perfetto::trace_processor::perf_importer {
 
@@ -29,8 +28,7 @@ base::Status AuxtraceRecord::Parse(const Record& record) {
     return base::ErrStatus("Failed to parse PERF_RECORD_AUXTRACE");
   }
 
-  uint64_t unused;
-  if (!SafeAdd(offset, size, &unused)) {
+  if (offset > std::numeric_limits<decltype(offset)>::max() - size) {
     return base::ErrStatus("AUXTRACE record overflows");
   }
 

diff --git a/src/trace_processor/importers/perf/util.h b/src/trace_processor/importers/perf/util.h
@@ -18,21 +18,10 @@
 #define SRC_TRACE_PROCESSOR_IMPORTERS_PERF_UTIL_H_
 
 #include <cstddef>
-#include <cstdint>
 #include <type_traits>
 
 namespace perfetto::trace_processor::perf_importer {
 
-template <typename A, typename B, typename Res>
-inline bool SafeAdd(A a, B b, Res* result) {
-  return !__builtin_add_overflow(a, b, result);
-}
-
-template <typename A, typename B, typename Res>
-inline bool SafeMultiply(A a, B b, Res* result) {
-  return !__builtin_mul_overflow(a, b, result);
-}
-
 template <typename A,
           typename Res,
           typename = std::enable_if_t<std::is_integral<A>::value &&