Provide __NR_getrandom fillins in urandom test too.

The urandom test added in 3e502c84f0 assumed that __NR_getrandom was
defined by the system's headers, but urandom.c doesn't. This change
pulls the fills for that system call into a common header that's used by
both.

Change-Id: I71c3b9bfa69c34b320e724a4c977cd63163cbdec
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/40067
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: Adam Langley <agl@google.com>

crypto/fipsmodule/rand/getrandom_fillin.h

@@ -0,0 +1,64 @@
+/* Copyright (c) 2020, Google Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
+
+#ifndef OPENSSL_HEADER_CRYPTO_RAND_GETRANDOM_FILLIN_H
+#define OPENSSL_HEADER_CRYPTO_RAND_GETRANDOM_FILLIN_H
+
+#include <openssl/base.h>
+
+
+#if defined(OPENSSL_LINUX)
+
+#include <sys/syscall.h>
+
+#if defined(OPENSSL_X86_64)
+#define EXPECTED_NR_getrandom 318
+#elif defined(OPENSSL_X86)
+#define EXPECTED_NR_getrandom 355
+#elif defined(OPENSSL_AARCH64)
+#define EXPECTED_NR_getrandom 278
+#elif defined(OPENSSL_ARM)
+#define EXPECTED_NR_getrandom 384
+#elif defined(OPENSSL_PPC64LE)
+#define EXPECTED_NR_getrandom 359
+#endif
+
+#if defined(EXPECTED_NR_getrandom)
+#define USE_NR_getrandom
+
+#if defined(__NR_getrandom)
+
+#if __NR_getrandom != EXPECTED_NR_getrandom
+#error "system call number for getrandom is not the expected value"
+#endif
+
+#else  // __NR_getrandom
+
+#define __NR_getrandom EXPECTED_NR_getrandom
+
+#endif  // __NR_getrandom
+
+#endif  // EXPECTED_NR_getrandom
+
+#if !defined(GRND_NONBLOCK)
+#define GRND_NONBLOCK 1
+#endif
+#if !defined(GRND_RANDOM)
+#define GRND_RANDOM 2
+#endif
+
+#endif  // OPENSSL_LINUX
+
+
+#endif  // OPENSSL_HEADER_CRYPTO_RAND_GETRANDOM_FILLIN_H

crypto/fipsmodule/rand/urandom.c

@@ -65,38 +65,12 @@
 #include <openssl/thread.h>
 #include <openssl/mem.h>
 
+#include "getrandom_fillin.h"
 #include "../delocate.h"
 #include "../../internal.h"
 
 
-#if defined(OPENSSL_LINUX)
-
-#if defined(OPENSSL_X86_64)
-#define EXPECTED_NR_getrandom 318
-#elif defined(OPENSSL_X86)
-#define EXPECTED_NR_getrandom 355
-#elif defined(OPENSSL_AARCH64)
-#define EXPECTED_NR_getrandom 278
-#elif defined(OPENSSL_ARM)
-#define EXPECTED_NR_getrandom 384
-#elif defined(OPENSSL_PPC64LE)
-#define EXPECTED_NR_getrandom 359
-#endif
-
-#if defined(EXPECTED_NR_getrandom)
-#define USE_NR_getrandom
-
-#if defined(__NR_getrandom)
-
-#if __NR_getrandom != EXPECTED_NR_getrandom
-#error "system call number for getrandom is not the expected value"
-#endif
-
-#else  // __NR_getrandom
-
-#define __NR_getrandom EXPECTED_NR_getrandom
-
-#endif  // __NR_getrandom
+#if defined(USE_NR_getrandom)
 
 #if defined(OPENSSL_MSAN)
 void __msan_unpoison(void *, size_t);
@@ -119,16 +93,7 @@ static ssize_t boringssl_getrandom(void *buf, size_t buf_len, unsigned flags) {
   return ret;
 }
 
-#endif  // EXPECTED_NR_getrandom
-
-#if !defined(GRND_NONBLOCK)
-#define GRND_NONBLOCK 1
-#endif
-#if !defined(GRND_RANDOM)
-#define GRND_RANDOM 2
-#endif
-
-#endif  // OPENSSL_LINUX
+#endif  // USE_NR_getrandom
 
 // rand_lock is used to protect the |*_requested| variables.
 DEFINE_STATIC_MUTEX(rand_lock)

crypto/fipsmodule/rand/urandom_test.cc

@@ -18,11 +18,10 @@
 #include <openssl/rand.h>
 
 #include "internal.h"
+#include "getrandom_fillin.h"
 
-
-#if defined(OPENSSL_X86_64) && defined(OPENSSL_LINUX) && \
-    !defined(BORINGSSL_SHARED_LIBRARY) &&                \
-    !defined(BORINGSSL_UNSAFE_DETERMINISTIC_MODE)
+#if defined(OPENSSL_X86_64) && !defined(BORINGSSL_SHARED_LIBRARY) && \
+    !defined(BORINGSSL_UNSAFE_DETERMINISTIC_MODE) && defined(USE_NR_getrandom)
 
 #include <linux/random.h>
 #include <sys/ptrace.h>
@@ -476,4 +475,5 @@ int main(int argc, char **argv) {
   return 0;
 }
 
-#endif  // X86_64 && LINUX && !SHARED_LIBRARY && !UNSAFE_DETERMINISTIC_MODE
+#endif  // X86_64 && !SHARED_LIBRARY && !UNSAFE_DETERMINISTIC_MODE &&
+        // USE_NR_getrandom