getrandom: Override incompatible system function on Solaris 11.

* lib/sys_random.in.h (getrandom): Override if REPLACE_GETRANDOM is 1.
* lib/getrandom.c (getrandom): When the system has getrandom, just
invoke it.
* m4/getrandom.m4 (gl_FUNC_GETRANDOM): Set REPLACE_GETRANDOM if the
system's getrandom function's prototype is not the expected one.
* m4/sys_random_h.m4 (gl_SYS_RANDOM_H_DEFAULTS): Initialize
REPLACE_GETRANDOM.
* modules/sys_random (Makefile.am): Substitute REPLACE_GETRANDOM.
* modules/getrandom (modules/getrandom): Consider REPLACE_GETRANDOM.
* tests/test-getrandom.c (main): Allow error EINVAL as an alternative to
EAGAIN.
* doc/glibc-functions/getrandom.texi: Mention the new module and the
Solaris problem.

2 files changed, 21 insertions, 3 deletions

diff --git a/lib/getrandom.c b/lib/getrandom.c
index 9b6ecb43be..f20ffe0112 100644
--- a/lib/getrandom.c
+++ b/lib/getrandom.c
@@ -21,16 +21,21 @@
 
 #include <sys/random.h>
 
-#include "minmax.h"
 #include <fcntl.h>
 #include <stdbool.h>
 #include <unistd.h>
 
+#include "minmax.h"
+
 /* Set BUFFER (of size LENGTH) to random bytes under the control of FLAGS.
    Return the number of bytes written, or -1 on error.  */
 ssize_t
 getrandom (void *buffer, size_t length, unsigned int flags)
+#undef getrandom
 {
+#if HAVE_GETRANDOM
+  return getrandom (buffer, length, flags);
+#else
   static int randfd[2] = { -1, -1 };
   bool devrandom = (flags & GRND_RANDOM) != 0;
   int fd = randfd[devrandom];
@@ -49,4 +54,5 @@ getrandom (void *buffer, size_t length, unsigned int flags)
     }
 
   return read (fd, buffer, length);
+#endif
 }
diff --git a/lib/sys_random.in.h b/lib/sys_random.in.h
index 3997cf4c3b..4d12db95ea 100644
--- a/lib/sys_random.in.h
+++ b/lib/sys_random.in.h
@@ -51,13 +51,25 @@
 
 #if @GNULIB_GETRANDOM@
 /* Fill a buffer with random bytes.  */
-# if !@HAVE_GETRANDOM@
+# if @REPLACE_GETRANDOM@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef getrandom
+#   define getrandom rpl_getrandom
+#  endif
+_GL_FUNCDECL_RPL (getrandom, ssize_t,
+                  (void *buffer, size_t length, unsigned int flags)
+                  _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_RPL (getrandom, ssize_t,
+                  (void *buffer, size_t length, unsigned int flags));
+# else
+#  if !@HAVE_GETRANDOM@
 _GL_FUNCDECL_SYS (getrandom, ssize_t,
                   (void *buffer, size_t length, unsigned int flags)
                   _GL_ARG_NONNULL ((1)));
-# endif
+#  endif
 _GL_CXXALIAS_SYS (getrandom, ssize_t,
                   (void *buffer, size_t length, unsigned int flags));
+# endif
 _GL_CXXALIASWARN (getrandom);
 #elif defined GNULIB_POSIXCHECK
 # undef getrandom