[PATCH v3 23/48] vfork: Use clone if arch does not have the vfork syscall

[Markos Chandras]

From: Markos Chandras <markos.chandras at imgtec.com>

Signed-off-by: Markos Chandras <markos.chandras at imgtec.com>
---
 libc/sysdeps/linux/common/vfork.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/libc/sysdeps/linux/common/vfork.c b/libc/sysdeps/linux/common/vfork.c
index a70ed4a..bbf5638 100644
--- a/libc/sysdeps/linux/common/vfork.c
+++ b/libc/sysdeps/linux/common/vfork.c
@@ -4,6 +4,9 @@
  * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
  */
 
+#include <signal.h>
+#include <unistd.h>
+#include <sys/types.h>
 #include <sys/syscall.h>
 
 #if (defined __NR_vfork || (defined __ARCH_USE_MMU__ && defined __NR_fork)) && (defined __USE_BSD || defined __USE_XOPEN_EXTENDED)
@@ -12,6 +15,24 @@ extern __typeof(vfork) __vfork attribute_hidden;
 
 # ifdef __NR_vfork
 #  define __NR___vfork __NR_vfork
+
+#if defined(__NR_clone) && !defined(__NR_vfork)
+
+pid_t __vfork(void)
+{
+	pid_t pid = INLINE_SYSCALL(clone, 4, SIGCHLD,
+				   NULL, NULL, NULL);
+
+	if (pid<0)
+		return -1
+
+	return pid;
+}
+weak_alias(__vfork, vfork)
+libc_hidden_weak(vfork)
+
+#elif defined(__NR_vfork)
+
 _syscall0(pid_t, __vfork)
 # else
 /* Trivial implementation for arches that lack vfork */
-- 
1.8.1.1