[compiler-rt] [compiler-rt][rtsan] Fix #123484 for glibc < 2.21 (PR #123664)

[Chris Apple via llvm-commits]

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@@ -927,8 +927,13 @@ INTERCEPTOR(ssize_t, recvmsg, int socket, struct msghdr *message, int flags) {
 }
 
 #if SANITIZER_INTERCEPT_RECVMMSG
+#if defined(__GLIBC_MINOR__) && __GLIBC_MINOR__ < 21
+INTERCEPTOR(int, recvmmsg, int socket, struct mmsghdr *message,
+            unsigned int len, int flags, const struct timespec *timeout) {
+#else
 INTERCEPTOR(int, recvmmsg, int socket, struct mmsghdr *message,
             unsigned int len, int flags, struct timespec *timeout) {
+#endif
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cjappl wrote:

I would have a comment here saying what this is finishing

#endif  defined(__GLIBC_MINOR__) && __GLIBC_MINOR__ < 21

https://github.com/llvm/llvm-project/pull/123664