Index: lib/sanitizer_common/sanitizer_common.h
===================================================================
--- lib/sanitizer_common/sanitizer_common.h
+++ lib/sanitizer_common/sanitizer_common.h
@@ -919,6 +919,10 @@
 
 void CheckNoDeepBind(const char *filename, int flag);
 
+// Returns the requested amount of random data (up to 256 bytes) that can then
+// be used to seed a PRNG.
+bool GetRandom(void *buffer, uptr length);
+
 }  // namespace __sanitizer
 
 inline void *operator new(__sanitizer::operator_new_size_type size,
Index: lib/sanitizer_common/sanitizer_linux.cc
===================================================================
--- lib/sanitizer_common/sanitizer_linux.cc
+++ lib/sanitizer_common/sanitizer_linux.cc
@@ -1604,6 +1604,32 @@
   return 0;
 }
 
+bool GetRandom(void *buffer, uptr length) {
+  if (!buffer || !length || length > 256)
+    return false;
+#if defined(__NR_getrandom)
+  static atomic_uint8_t skip_getrandom_syscall;
+  if (!atomic_load_relaxed(&skip_getrandom_syscall)) {
+    // Up to 256 bytes, getrandom will not be interrupted.
+    uptr res = internal_syscall(SYSCALL(getrandom), buffer, length, 0);
+    int rverrno = 0;
+    if (internal_iserror(res, &rverrno) && rverrno == ENOSYS)
+      atomic_store_relaxed(&skip_getrandom_syscall, 1);
+    else if (res == length)
+      return true;
+  }
+#endif
+  uptr fd = internal_open("/dev/urandom", O_RDONLY);
+  if (internal_iserror(fd))
+    return false;
+  // internal_read deals with EINTR.
+  uptr res = internal_read(fd, buffer, length);
+  if (internal_iserror(res))
+    return false;
+  internal_close(fd);
+  return true;
+}
+
 } // namespace __sanitizer
 
 #endif // SANITIZER_FREEBSD || SANITIZER_LINUX
Index: lib/sanitizer_common/sanitizer_mac.cc
===================================================================
--- lib/sanitizer_common/sanitizer_mac.cc
+++ lib/sanitizer_common/sanitizer_mac.cc
@@ -923,6 +923,11 @@
   // Do nothing.
 }
 
+// FIXME: implement on this platform.
+bool GetRandom(void *buffer, uptr length) {
+  UNIMPLEMENTED();
+}
+
 }  // namespace __sanitizer
 
 #endif  // SANITIZER_MAC
Index: lib/sanitizer_common/sanitizer_win.cc
===================================================================
--- lib/sanitizer_common/sanitizer_win.cc
+++ lib/sanitizer_common/sanitizer_win.cc
@@ -1002,6 +1002,11 @@
   // Do nothing.
 }
 
+// FIXME: implement on this platform.
+bool GetRandom(void *buffer, uptr length) {
+  UNIMPLEMENTED();
+}
+
 }  // namespace __sanitizer
 
 #endif  // _WIN32
Index: lib/sanitizer_common/tests/sanitizer_common_test.cc
===================================================================
--- lib/sanitizer_common/tests/sanitizer_common_test.cc
+++ lib/sanitizer_common/tests/sanitizer_common_test.cc
@@ -300,4 +300,21 @@
   EXPECT_STREQ("012345678", str.data());
 }
 
+#if SANITIZER_LINUX
+TEST(SanitizerCommon, GetRandom) {
+  u8 buffer_1[32], buffer_2[32];
+  EXPECT_FALSE(GetRandom(nullptr, 32));
+  EXPECT_FALSE(GetRandom(buffer_1, 0));
+  EXPECT_FALSE(GetRandom(buffer_1, 512));
+  EXPECT_EQ(ARRAY_SIZE(buffer_1), ARRAY_SIZE(buffer_2));
+  for (uptr size = 4; size <= ARRAY_SIZE(buffer_1); size += 4) {
+    for (uptr i = 0; i < 100; i++) {
+      EXPECT_TRUE(GetRandom(buffer_1, size));
+      EXPECT_TRUE(GetRandom(buffer_2, size));
+      EXPECT_NE(internal_memcmp(buffer_1, buffer_2, size), 0);
+    }
+  }
+}
+#endif
+
 }  // namespace __sanitizer