[git commit] seedrng: fix for glibc <= 2.24 not providing getrandom()

[Denys Vlasenko]

commit: https://git.busybox.net/busybox/commit/?id=200a9669fbf6f06894e4243cccc9fc11a1a6073a
branch: https://git.busybox.net/busybox/commit/?id=refs/heads/master

Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
 miscutils/seedrng.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/miscutils/seedrng.c b/miscutils/seedrng.c
index 967741dc7..7cc855141 100644
--- a/miscutils/seedrng.c
+++ b/miscutils/seedrng.c
@@ -45,6 +45,20 @@
 #include <sys/random.h>
 #include <sys/file.h>
 
+/* Fix up glibc <= 2.24 not having getrandom() */
+#if defined(__GLIBC__) && __GLIBC__ == 2 && __GLIBC_MINOR__ <= 24
+#include <sys/syscall.h>
+# define getrandom(...) bb_getrandom(__VA_ARGS__)
+static ssize_t getrandom(void *buffer, size_t length, unsigned flags)
+{
+# if defined(__NR_getrandom)
+	return syscall(__NR_getrandom, buffer, length, flags);
+# else
+	return ENOSYS;
+# endif
+}
+#endif
+
 #ifndef GRND_INSECURE
 #define GRND_INSECURE 0x0004 /* Apparently some headers don't ship with this yet. */
 #endif