mbedtls/getrandom-syscall-fallback.patch

Index: mbedtls-1.3.10/library/entropy_poll.c
===================================================================
--- mbedtls-1.3.10.orig/library/entropy_poll.c
+++ mbedtls-1.3.10/library/entropy_poll.c
@@ -81,40 +81,35 @@ int platform_entropy_poll( void *data, u
 #include <sys/syscall.h>
 #if defined(SYS_getrandom)
 #define HAVE_GETRANDOM
-static int getrandom_wrapper( void *buf, size_t buflen, unsigned int flags )
+static ssize_t getrandom_wrapper( void *buf, size_t buflen, unsigned int flags )
 {
     return( syscall( SYS_getrandom, buf, buflen, flags ) );
 }
 #endif /* SYS_getrandom */
 #endif /* __linux__ */
 
-#if defined(HAVE_GETRANDOM)
-
+#include <stdio.h>
 #include <errno.h>
 
 int platform_entropy_poll( void *data,
                            unsigned char *output, size_t len, size_t *olen )
 {
-    int ret;
+    FILE *file;
+    size_t ret;
     ((void) data);
 
-    if( ( ret = getrandom_wrapper( output, len, 0 ) ) < 0 )
-        return( POLARSSL_ERR_ENTROPY_SOURCE_FAILED );
-
-    *olen = ret;
-    return( 0 );
-}
-
-#else /* HAVE_GETRANDOM */
+#if defined(HAVE_GETRANDOM)
+    ssize_t sysret;
 
-#include <stdio.h>
+    if( ( sysret = getrandom_wrapper( output, len, 0 ) ) >= 0 )
+    {
+	*olen = sysret;
+	return( 0 );
+    }
+    if (sysret < 0 && errno != ENOSYS)
+        return( POLARSSL_ERR_ENTROPY_SOURCE_FAILED );
 
-int platform_entropy_poll( void *data,
-                           unsigned char *output, size_t len, size_t *olen )
-{
-    FILE *file;
-    size_t ret;
-    ((void) data);
+#endif /* HAVE_GETRANDOM */
 
     *olen = 0;
 
@@ -134,7 +129,6 @@ int platform_entropy_poll( void *data,
 
     return( 0 );
 }
-#endif /* HAVE_GETRANDOM */
 #endif /* _WIN32 && !EFIX64 && !EFI32 */
 #endif /* !POLARSSL_NO_PLATFORM_ENTROPY */