diff --git a/include/llvm/ProfileData/InstrProfReader.h b/include/llvm/ProfileData/InstrProfReader.h
index 3bb482e20f3..3e18c76c57d 100644
--- a/include/llvm/ProfileData/InstrProfReader.h
+++ b/include/llvm/ProfileData/InstrProfReader.h
@@ -165,6 +165,7 @@ private:
   const ProfileData *DataEnd;
   const uint64_t *CountersStart;
   const char *NamesStart;
+  const char *ProfileEnd;
 
   RawInstrProfReader(const TextInstrProfReader &) LLVM_DELETED_FUNCTION;
   RawInstrProfReader &operator=(const TextInstrProfReader &)
@@ -178,6 +179,7 @@ public:
   error_code readNextRecord(InstrProfRecord &Record) override;
 
 private:
+  error_code readNextHeader(const char *CurrentPos);
   error_code readHeader(const RawHeader &Header);
   template <class IntT>
   IntT swap(IntT Int) const {
diff --git a/lib/ProfileData/InstrProfReader.cpp b/lib/ProfileData/InstrProfReader.cpp
index 2ab0eb9449c..7014f5e5cc8 100644
--- a/lib/ProfileData/InstrProfReader.cpp
+++ b/lib/ProfileData/InstrProfReader.cpp
@@ -172,6 +172,29 @@ error_code RawInstrProfReader<IntPtrT>::readHeader() {
   return readHeader(*Header);
 }
 
+template <class IntPtrT>
+error_code RawInstrProfReader<IntPtrT>::readNextHeader(const char *CurrentPos) {
+  const char *End = DataBuffer->getBufferEnd();
+  // Skip zero padding between profiles.
+  while (CurrentPos != End && *CurrentPos == 0)
+    ++CurrentPos;
+  // If there's nothing left, we're done.
+  if (CurrentPos == End)
+    return instrprof_error::eof;
+  // If there isn't enough space for another header, this is probably just
+  // garbage at the end of the file.
+  if (CurrentPos + sizeof(RawHeader) > End)
+    return instrprof_error::malformed;
+  // The magic should have the same byte order as in the previous header.
+  uint64_t Magic = *reinterpret_cast<const uint64_t *>(CurrentPos);
+  if (Magic != swap(getRawMagic<IntPtrT>()))
+    return instrprof_error::bad_magic;
+
+  // There's another profile to read, so we need to process the header.
+  auto *Header = reinterpret_cast<const RawHeader *>(CurrentPos);
+  return readHeader(*Header);
+}
+
 static uint64_t getRawVersion() {
   return 1;
 }
@@ -190,16 +213,17 @@ error_code RawInstrProfReader<IntPtrT>::readHeader(const RawHeader &Header) {
   ptrdiff_t DataOffset = sizeof(RawHeader);
   ptrdiff_t CountersOffset = DataOffset + sizeof(ProfileData) * DataSize;
   ptrdiff_t NamesOffset = CountersOffset + sizeof(uint64_t) * CountersSize;
-  size_t FileSize = NamesOffset + sizeof(char) * NamesSize;
+  size_t ProfileSize = NamesOffset + sizeof(char) * NamesSize;
 
-  if (FileSize != DataBuffer->getBufferSize())
+  auto *Start = reinterpret_cast<const char *>(&Header);
+  if (Start + ProfileSize > DataBuffer->getBufferEnd())
     return error(instrprof_error::bad_header);
 
-  const char *Start = DataBuffer->getBufferStart();
   Data = reinterpret_cast<const ProfileData *>(Start + DataOffset);
   DataEnd = Data + DataSize;
   CountersStart = reinterpret_cast<const uint64_t *>(Start + CountersOffset);
   NamesStart = Start + NamesOffset;
+  ProfileEnd = Start + ProfileSize;
 
   return success();
 }
@@ -208,7 +232,8 @@ template <class IntPtrT>
 error_code
 RawInstrProfReader<IntPtrT>::readNextRecord(InstrProfRecord &Record) {
   if (Data == DataEnd)
-    return error(instrprof_error::eof);
+    if (error_code EC = readNextHeader(ProfileEnd))
+      return EC;
 
   // Get the raw data.
   StringRef RawName(getName(Data->NamePtr), swap(Data->NameSize));
diff --git a/test/tools/llvm-profdata/raw-two-profiles.test b/test/tools/llvm-profdata/raw-two-profiles.test
new file mode 100644
index 00000000000..3260836ba66
--- /dev/null
+++ b/test/tools/llvm-profdata/raw-two-profiles.test
@@ -0,0 +1,64 @@
+RUN: printf '\201rforpl\377' > %t-foo.profraw
+RUN: printf '\1\0\0\0\0\0\0\0' >> %t-foo.profraw
+RUN: printf '\1\0\0\0\0\0\0\0' >> %t-foo.profraw
+RUN: printf '\1\0\0\0\0\0\0\0' >> %t-foo.profraw
+RUN: printf '\3\0\0\0\0\0\0\0' >> %t-foo.profraw
+RUN: printf '\0\0\4\0\1\0\0\0' >> %t-foo.profraw
+RUN: printf '\0\0\4\0\2\0\0\0' >> %t-foo.profraw
+
+RUN: printf '\3\0\0\0' >> %t-foo.profraw
+RUN: printf '\1\0\0\0' >> %t-foo.profraw
+RUN: printf '\1\0\0\0\0\0\0\0' >> %t-foo.profraw
+RUN: printf '\0\0\4\0\2\0\0\0' >> %t-foo.profraw
+RUN: printf '\0\0\4\0\1\0\0\0' >> %t-foo.profraw
+
+RUN: printf '\023\0\0\0\0\0\0\0' >> %t-foo.profraw
+RUN: printf 'foo' >> %t-foo.profraw
+
+RUN: printf '\201rforpl\377' > %t-bar.profraw
+RUN: printf '\1\0\0\0\0\0\0\0' >> %t-bar.profraw
+RUN: printf '\1\0\0\0\0\0\0\0' >> %t-bar.profraw
+RUN: printf '\2\0\0\0\0\0\0\0' >> %t-bar.profraw
+RUN: printf '\3\0\0\0\0\0\0\0' >> %t-bar.profraw
+RUN: printf '\0\0\6\0\1\0\0\0' >> %t-bar.profraw
+RUN: printf '\0\0\6\0\2\0\0\0' >> %t-bar.profraw
+
+RUN: printf '\3\0\0\0' >> %t-bar.profraw
+RUN: printf '\2\0\0\0' >> %t-bar.profraw
+RUN: printf '\2\0\0\0\0\0\0\0' >> %t-bar.profraw
+RUN: printf '\0\0\6\0\2\0\0\0' >> %t-bar.profraw
+RUN: printf '\0\0\6\0\1\0\0\0' >> %t-bar.profraw
+
+RUN: printf '\067\0\0\0\0\0\0\0' >> %t-bar.profraw
+RUN: printf '\101\0\0\0\0\0\0\0' >> %t-bar.profraw
+RUN: printf 'bar' >> %t-bar.profraw
+
+Versions of the profiles that are padded to eight byte alignment.
+RUN: cat %t-foo.profraw > %t-foo-padded.profraw
+RUN: printf '\0\0\0\0\0' >> %t-foo-padded.profraw
+RUN: cat %t-bar.profraw > %t-bar-padded.profraw
+RUN: printf '\0\0\0\0\0' >> %t-bar-padded.profraw
+
+RUN: cat %t-foo.profraw %t-bar.profraw > %t-nopad.profraw
+RUN: cat %t-foo-padded.profraw %t-bar.profraw > %t-pad-between.profraw
+RUN: cat %t-foo-padded.profraw %t-bar-padded.profraw > %t-pad.profraw
+
+RUN: llvm-profdata show %t-nopad.profraw -all-functions -counts | FileCheck %s
+RUN: llvm-profdata show %t-pad-between.profraw -all-functions -counts | FileCheck %s
+RUN: llvm-profdata show %t-pad.profraw -all-functions -counts | FileCheck %s
+
+CHECK: Counters:
+CHECK:   foo:
+CHECK:     Hash: 0x0000000000000001
+CHECK:     Counters: 1
+CHECK:     Function count: 19
+CHECK:     Block counts: []
+CHECK:   bar:
+CHECK:     Hash: 0x0000000000000002
+CHECK:     Counters: 2
+CHECK:     Function count: 55
+CHECK:     Block counts: [65]
+CHECK: Functions shown: 2
+CHECK: Total functions: 2
+CHECK: Maximum function count: 55
+CHECK: Maximum internal block count: 65