diff --git a/compiler-rt/lib/profile/InstrProfilingPlatformLinux.c b/compiler-rt/lib/profile/InstrProfilingPlatformLinux.c
--- a/compiler-rt/lib/profile/InstrProfilingPlatformLinux.c
+++ b/compiler-rt/lib/profile/InstrProfilingPlatformLinux.c
@@ -94,8 +94,8 @@
  * Write binary id length and then its data, because binary id does not
  * have a fixed length.
  */
-int WriteOneBinaryId(ProfDataWriter *Writer, uint64_t BinaryIdLen,
-                     const uint8_t *BinaryIdData) {
+static int WriteOneBinaryId(ProfDataWriter *Writer, uint64_t BinaryIdLen,
+                            const uint8_t *BinaryIdData) {
   ProfDataIOVec BinaryIdIOVec[] = {
       {&BinaryIdLen, sizeof(uint64_t), 1, 0},
       {BinaryIdData, sizeof(uint8_t), BinaryIdLen, 0}};
@@ -119,7 +119,8 @@
  * Note sections like .note.ABI-tag and .note.gnu.build-id are aligned
  * to 4 bytes, so round n_namesz and n_descsz to the nearest 4 bytes.
  */
-int WriteBinaryIdForNote(ProfDataWriter *Writer, const ElfW(Nhdr) * Note) {
+static int WriteBinaryIdForNote(ProfDataWriter *Writer,
+                                const ElfW(Nhdr) * Note) {
   int BinaryIdSize = 0;
 
   const char *NoteName = (const char *)Note + sizeof(ElfW(Nhdr));
@@ -144,8 +145,8 @@
  * If writer is given, write binary ids into profiles.
  * If an error happens while writing, return -1.
  */
-int WriteBinaryIds(ProfDataWriter *Writer, const ElfW(Nhdr) * Note,
-                   const ElfW(Nhdr) * NotesEnd) {
+static int WriteBinaryIds(ProfDataWriter *Writer, const ElfW(Nhdr) * Note,
+                          const ElfW(Nhdr) * NotesEnd) {
   int TotalBinaryIdsSize = 0;
   while (Note < NotesEnd) {
     int Result = WriteBinaryIdForNote(Writer, Note);