[PATCH] D66979: [InstrProf] Tighten a check for malformed data records in raw profiles

[David Li via Phabricator via llvm-commits]

davidxl added inline comments.


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Comment at: llvm/include/llvm/ProfileData/InstrProfReader.h:271
 
-  const uint64_t *getCounter(IntPtrT CounterPtr) const {
-    ptrdiff_t Offset = (swap(CounterPtr) - CountersDelta) / sizeof(uint64_t);
+  ptrdiff_t getCounterOffset(IntPtrT CounterPtr) const {
+    return (swap(CounterPtr) - CountersDelta) / sizeof(uint64_t);
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add a documentation " Returns the double word offset of a counter to the start of the counter segment'


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Comment at: llvm/lib/ProfileData/InstrProfReader.cpp:419
 
-  // Check bounds.
-  if (RawCounts.data() < CountersStart ||
-      RawCounts.data() + RawCounts.size() > NamesStartAsCounter)
+  // Check bounds. Note that the counter pointer embedded in the data record
+  // may itself be corrupt.
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how does the corruption happen?


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Comment at: llvm/lib/ProfileData/InstrProfReader.cpp:423
     return error(instrprof_error::malformed);
+  ptrdiff_t CounterOffset = getCounterOffset(CounterPtr);
+  if (CounterOffset < 0 || CounterOffset > MaxNumCounters ||
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should it assert to be zero?


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  https://reviews.llvm.org/D66979/new/

https://reviews.llvm.org/D66979