util/rand_xor: use getrandom() when available

[mesa.git] / src / util / rand_xor.c

diff --git a/src/util/rand_xor.c b/src/util/rand_xor.c
index de04bbc284f7a5e75fba95b284b0c74dc1734437..31612d576602e5361c67c51f1f90577a17c21ed0 100644 (file)
--- a/src/util/rand_xor.c
+++ b/src/util/rand_xor.c
@@ -23,6 +23,9 @@
  */
 
 #if defined(__linux__)
  */
 
 #if defined(__linux__)

+#if defined(HAVE_GETRANDOM)
+#include <sys/random.h>
+#endif

 #include <sys/file.h>
 #include <unistd.h>
 #include <fcntl.h>
 #include <sys/file.h>
 #include <unistd.h>
 #include <fcntl.h>


@@ -58,11 +61,18 @@ s_rand_xorshift128plus(uint64_t *seed, bool randomised_seed)
       goto fixed_seed;
 
 #if defined(__linux__)
       goto fixed_seed;
 
 #if defined(__linux__)

+   size_t seed_size = sizeof(uint64_t) * 2;
+
+#if defined(HAVE_GETRANDOM)
+   ssize_t ret = getrandom(seed, seed_size, GRND_NONBLOCK);
+   if (ret == seed_size)
+      return;
+#endif
+

    int fd = open("/dev/urandom", O_RDONLY);
    if (fd < 0)
       goto fixed_seed;
 
    int fd = open("/dev/urandom", O_RDONLY);
    if (fd < 0)
       goto fixed_seed;
 

-   size_t seed_size = sizeof(uint64_t) * 2;

    if (read(fd, seed, seed_size) != seed_size) {
       close(fd);
       goto fixed_seed;
    if (read(fd, seed, seed_size) != seed_size) {
       close(fd);
       goto fixed_seed;