[Sanitizers] Porting getrandom/getentropy interceptors to FreeBSD

- Available from 12.x branch, by the time it lands next year in FreeBSD tree, the 11.x's might be EOL.
- Intentionally changed the getrandom test to C code as with 12.0 (might be fixed in CURRENT since), there is a linkage issue in C++ context.

Reviewers: emaste, dim, vitalybuka

Reviewed-By: vitalybuka

Differential Revision: https://reviews.llvm.org/D68451

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@374315 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/sanitizer_common/sanitizer_common_interceptors.inc b/lib/sanitizer_common/sanitizer_common_interceptors.inc
index 7cae945..50e3558 100644
--- a/lib/sanitizer_common/sanitizer_common_interceptors.inc
+++ b/lib/sanitizer_common/sanitizer_common_interceptors.inc
@@ -9608,6 +9608,21 @@
 #define INIT_CRYPT_R
 #endif
 
+#if SANITIZER_INTERCEPT_GETENTROPY
+INTERCEPTOR(int, getentropy, void *buf, SIZE_T buflen) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, getentropy, buf, buflen);
+  int r = REAL(getentropy)(buf, buflen);
+  if (r == 0) {
+    COMMON_INTERCEPTOR_WRITE_RANGE(ctx, buf, buflen);
+  }
+  return r;
+}
+#define INIT_GETENTROPY COMMON_INTERCEPT_FUNCTION(getentropy)
+#else
+#define INIT_GETENTROPY
+#endif
+
 static void InitializeCommonInterceptors() {
 #if SI_POSIX
   static u64 metadata_mem[sizeof(MetadataHashMap) / sizeof(u64) + 1];
@@ -9908,6 +9923,7 @@
   INIT_GETRANDOM;
   INIT_CRYPT;
   INIT_CRYPT_R;
+  INIT_GETENTROPY;
 
   INIT___PRINTF_CHK;
 }
diff --git a/lib/sanitizer_common/sanitizer_platform_interceptors.h b/lib/sanitizer_common/sanitizer_platform_interceptors.h
index 54a1699..4aeecf1 100644
--- a/lib/sanitizer_common/sanitizer_platform_interceptors.h
+++ b/lib/sanitizer_common/sanitizer_platform_interceptors.h
@@ -569,9 +569,10 @@
 #define SANITIZER_INTERCEPT_CRYPT (SI_POSIX && !SI_ANDROID)
 #define SANITIZER_INTERCEPT_CRYPT_R (SI_LINUX && !SI_ANDROID)
 
-#define SANITIZER_INTERCEPT_GETRANDOM (SI_LINUX && __GLIBC_PREREQ(2, 25))
+#define SANITIZER_INTERCEPT_GETRANDOM ((SI_LINUX && __GLIBC_PREREQ(2, 25)) || SI_FREEBSD)
 #define SANITIZER_INTERCEPT___CXA_ATEXIT SI_NETBSD
 #define SANITIZER_INTERCEPT_ATEXIT SI_NETBSD
 #define SANITIZER_INTERCEPT_PTHREAD_ATFORK SI_NETBSD
+#define SANITIZER_INTERCEPT_GETENTROPY SI_FREEBSD
 
 #endif  // #ifndef SANITIZER_PLATFORM_INTERCEPTORS_H
diff --git a/test/sanitizer_common/TestCases/Linux/getrandom.cpp b/test/sanitizer_common/TestCases/Linux/getrandom.cpp
deleted file mode 100644
index 08337f5..0000000
--- a/test/sanitizer_common/TestCases/Linux/getrandom.cpp
+++ /dev/null
@@ -1,22 +0,0 @@
-// RUN: %clangxx -O2 %s -o %t && %run %t
-// UNSUPPORTED: android
-//
-
-#include <sys/types.h>
-
-#if !defined(__GLIBC_PREREQ)
-#define __GLIBC_PREREQ(a, b) 0
-#endif
-
-#if __GLIBC_PREREQ(2, 25)
-#include <sys/random.h>
-#endif
-
-int main() {
-  char buf[16];
-  ssize_t n = 1;
-#if __GLIBC_PREREQ(2, 25)
-  n = getrandom(buf, sizeof(buf), 0);
-#endif
-  return (int)(n <= 0);
-}
diff --git a/test/sanitizer_common/TestCases/Posix/getrandom.c b/test/sanitizer_common/TestCases/Posix/getrandom.c
new file mode 100644
index 0000000..fdc08bc
--- /dev/null
+++ b/test/sanitizer_common/TestCases/Posix/getrandom.c
@@ -0,0 +1,26 @@
+// RUN: %clang -O2 %s -o %t && %run %t
+// UNSUPPORTED: android netbsd darwin solaris
+//
+
+#include <sys/types.h>
+
+#if !defined(__GLIBC_PREREQ)
+#define __GLIBC_PREREQ(a, b) 0
+#endif
+
+#if (defined(__linux__) && __GLIBC_PREREQ(2, 25)) || defined(__FreeBSD__)
+#define HAS_GETRANDOM
+#endif
+
+#if defined(HAS_GETRANDOM)
+#include <sys/random.h>
+#endif
+
+int main() {
+  char buf[16];
+  ssize_t n = 1;
+#if defined(HAS_GETRANDOM)
+  n = getrandom(buf, sizeof(buf), 0);
+#endif
+  return (int)(n <= 0);
+}