Revert r52180

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52182 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -3,13 +3,6 @@ Sun Oct 18 14:37:56 2015  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
 	* random.c (fill_random_bytes_urandom): add a comment why using
 	  O_NONBLOCK and O_NOCTTY.
 
-Sun Oct 18 13:30:56 2015  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
-
-	* random.c (fill_random_bytes_syscall): don't use GRND_NONBLOCK.
-	  It is meaningless. If SYS_getrandom(GRND_NONBLOCK) return
-	  EAGAIN, we eventually call fill_random_bytes_urandom() and
-	  it block such as SYS_getrandom() without GRND_NONBLOCK.
-
 Sun Oct 18 13:24:17 2015  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
 
 	* random.c (fill_random_bytes_syscall): use ATOMIC_SET() for

random.c

@@ -523,6 +523,10 @@ fill_random_bytes_syscall(void *seed, size_t size)
 #elif defined __linux__ && defined SYS_getrandom
 #include <linux/random.h>
 
+# ifndef GRND_NONBLOCK
+#   define GRND_NONBLOCK 0x0001	/* not defined in musl libc */
+# endif
+
 static int
 fill_random_bytes_syscall(void *seed, size_t size)
 {
@@ -530,7 +534,7 @@ fill_random_bytes_syscall(void *seed, size_t size)
     if (try_syscall) {
 	long ret;
 	errno = 0;
-	ret = syscall(SYS_getrandom, seed, size, 0);
+	ret = syscall(SYS_getrandom, seed, size, GRND_NONBLOCK);
 	if (errno == ENOSYS) {
 	    ATOMIC_SET(try_syscall, 0);
 	    return -1;