Revert "Update getentropy_linux.c from upstream."

This reverts commit 5faef47e438d20600655e2f5ef473c2d63cbf2c0.

Bug: http://b/31251721
Change-Id: I20a091f385fb77ccc68b8d9fb1d2aee3dec0d0ff

libc/bionic/getentropy_linux.c

diff --git a/libc/bionic/getentropy_linux.c b/libc/bionic/getentropy_linux.c
index 98fb6fb..409bd7d 100644
--- a/libc/bionic/getentropy_linux.c
+++ b/libc/bionic/getentropy_linux.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: getentropy_linux.c,v 1.42 2016/04/19 20:20:24 tj Exp $	*/
+/*	$OpenBSD: getentropy_linux.c,v 1.28 2014/07/20 03:24:10 deraadt Exp $	*/
 
 /*
  * Copyright (c) 2014 Theo de Raadt <deraadt@openbsd.org>
@@ -17,7 +17,7 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  *
  * Emulation of getentropy(2) as documented at:
- * http://man.openbsd.org/getentropy.2
+ * http://www.openbsd.org/cgi-bin/man.cgi/OpenBSD-current/man2/getentropy.2
  */
 
 #define	_POSIX_C_SOURCE	199309L
@@ -27,8 +27,8 @@
 #include <sys/ioctl.h>
 #include <sys/resource.h>
 #include <sys/syscall.h>
-#ifdef SYS__sysctl
-#include <linux/sysctl.h>
+#ifdef HAVE_SYS_SYSCTL_H
+#include <sys/sysctl.h>
 #endif
 #include <sys/statvfs.h>
 #include <sys/socket.h>
@@ -51,8 +51,8 @@
 #include <openssl/sha.h>
 #endif
 
-#include <linux/types.h>
 #include <linux/random.h>
+#include <linux/sysctl.h>
 #ifdef HAVE_GETAUXVAL
 #include <sys/auxv.h>
 #endif
@@ -76,7 +76,9 @@
 int	getentropy(void *buf, size_t len);
 
 static int gotdata(char *buf, size_t len);
+#ifdef SYS__getrandom
 static int getentropy_getrandom(void *buf, size_t len);
+#endif
 static int getentropy_urandom(void *buf, size_t len);
 #ifdef SYS__sysctl
 static int getentropy_sysctl(void *buf, size_t len);
@@ -93,17 +95,17 @@
 
 	if (len > 256) {
 		errno = EIO;
-		return (-1);
+		return -1;
 	}
 
+#ifdef SYS__getrandom
 	/*
 	 * Try descriptor-less getrandom()
 	 */
 	ret = getentropy_getrandom(buf, len);
 	if (ret != -1)
 		return (ret);
-	if (errno != ENOSYS)
-		return (-1);
+#endif
 
 	/*
 	 * Try to get entropy with /dev/urandom
@@ -120,7 +122,7 @@
 	 * Try to use sysctl CTL_KERN, KERN_RANDOM, RANDOM_UUID.
 	 * sysctl is a failsafe API, so it guarantees a result.  This
 	 * should work inside a chroot, or when file descriptors are
-	 * exhausted.
+	 * exhuasted.
 	 *
 	 * However this can fail if the Linux kernel removes support
 	 * for sysctl.  Starting in 2007, there have been efforts to
@@ -188,26 +190,39 @@
 	for (i = 0; i < len; ++i)
 		any_set |= buf[i];
 	if (any_set == 0)
-		return (-1);
-	return (0);
+		return -1;
+	return 0;
 }
 
+#ifdef SYS__getrandom
 static int
 getentropy_getrandom(void *buf, size_t len)
 {
-	int pre_errno = errno;
-	int ret;
+#if 0
+
+/* Hand-definitions until the API becomes commonplace */
+#ifndef SYS__getrandom
+#ifdef __LP64__
+#define SYS__getrandom 317
+#else
+#define SYS__getrandom 354
+#endif
+#endif
+	struct __getrandom_args args = {
+		.buf = buf;
+		.len = len;
+		.flags = 0;
+	};
+
 	if (len > 256)
 		return (-1);
-	do {
-		ret = syscall(SYS_getrandom, buf, len, 0);
-	} while (ret == -1 && errno == EINTR);
-
-	if ((size_t)ret != len)
-		return (-1);
-	errno = pre_errno;
-	return (0);
+	ret = syscall(SYS__getrandom, &args);
+	if (ret == len)
+		return (0);
+#endif
+	return -1;
 }
+#endif
 
 static int
 getentropy_urandom(void *buf, size_t len)
@@ -260,11 +275,11 @@
 	close(fd);
 	if (gotdata(buf, len) == 0) {
 		errno = save_errno;
-		return (0);		/* satisfied */
+		return 0;		/* satisfied */
 	}
 nodevrandom:
 	errno = EIO;
-	return (-1);
+	return -1;
 }
 
 #ifdef SYS__sysctl
@@ -282,7 +297,7 @@
 		struct __sysctl_args args = {
 			.name = mib,
 			.nlen = 3,
-			.oldval = (char *)buf + i,
+			.oldval = (char*) buf + i,
 			.oldlenp = &chunk,
 		};
 		if (syscall(SYS__sysctl, &args) != 0)
@@ -295,12 +310,13 @@
 	}
 sysctlfailed:
 	errno = EIO;
-	return (-1);
+	return -1;
 }
 #endif /* SYS__sysctl */
 
 #ifdef HAVE_OPENSSL
-static const int cl[] = {
+
+static int cl[] = {
 	CLOCK_REALTIME,
 #ifdef CLOCK_MONOTONIC
 	CLOCK_MONOTONIC,
@@ -331,7 +347,7 @@
 	SHA512_CTX *ctx = data;
 
 	SHA512_Update(ctx, &info->dlpi_addr, sizeof (info->dlpi_addr));
-	return (0);
+	return 0;
 }
 
 static int
@@ -540,9 +556,10 @@
 	memset(results, 0, sizeof results);
 	if (gotdata(buf, len) == 0) {
 		errno = save_errno;
-		return (0);		/* satisfied */
+		return 0;		/* satisfied */
 	}
 	errno = EIO;
-	return (-1);
+	return -1;
 }
+
 #endif /* HAVE_OPENSSL */