Revert "Use glibc's getrandom() instead of syscall when glibc > 2.25."
This reverts commit 9c46a60e6c3edc35d6369afdf5252a5c66aef5b3.
When the library is dynamically linked against Glibc (as is usually
the case with Glibc), it now requires a recent Glibc at runtime if it
was compiled with a recent Glibc. This is a loss of functionality for
no demonstrated benefit.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/library/entropy_poll.c b/library/entropy_poll.c
index 0f992f3..4bf660e 100644
--- a/library/entropy_poll.c
+++ b/library/entropy_poll.c
@@ -18,15 +18,9 @@
*/
#if defined(__linux__)
-#if !defined(_GNU_SOURCE)
/* Ensure that syscall() is available even when compiling with -std=c99 */
#define _GNU_SOURCE
#endif
-#include <features.h>
-#if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 25)
-#define HAVE_SYS_RANDOM 1
-#endif
-#endif
#include "common.h"
@@ -92,16 +86,10 @@
/*
* Test for Linux getrandom() support.
- * When the C library is GNU libc and its version is greater than 2.25,
- * include sys/random.h to use getrandom(),
- * otherwise use the generic use the generic syscall wrapper
+ * Since there is no wrapper in the libc yet, use the generic syscall wrapper
* available in GNU libc and compatible libc's (eg uClibc).
*/
-#if HAVE_SYS_RANDOM
-#include <sys/random.h>
-#include <errno.h>
-#define HAVE_GETRANDOM
-#elif (defined(__linux__) && defined(__GLIBC__)) || defined(__midipix__)
+#if ((defined(__linux__) && defined(__GLIBC__)) || defined(__midipix__))
#include <unistd.h>
#include <sys/syscall.h>
#if defined(SYS_getrandom)
@@ -167,11 +155,7 @@
((void) data);
#if defined(HAVE_GETRANDOM)
-#if HAVE_SYS_RANDOM
- ret = getrandom(output, len, 0);
-#else
ret = getrandom_wrapper( output, len, 0 );
-#endif
if( ret >= 0 )
{
*olen = ret;