commit 1d4b4b2994b5fc208963c0b795291f8c1f18becf
author Al Viro <viro@zeniv.linux.org.uk> Mon Oct 22 22:34:11 2012 -0400
committer Al Viro <viro@zeniv.linux.org.uk> Wed Nov 28 22:13:44 2012 -0500
tree befe27a3e2abc333b5bd81ee7381e4c5541f543f
parent 71613c3b871c5a9f27cc48f124251bcd3aa23be1

x86, um: switch to generic fork/vfork/clone

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/x86/kernel/process_64.c

diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 16c6365..74aac76 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -169,7 +169,7 @@
 	savesegment(ds, p->thread.ds);
 	memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
 
-	if (unlikely(!regs)) {
+	if (unlikely(p->flags & PF_KTHREAD)) {
 		/* kernel thread */
 		memset(childregs, 0, sizeof(struct pt_regs));
 		childregs->sp = (unsigned long)childregs;
@@ -181,10 +181,11 @@
 		childregs->flags = X86_EFLAGS_IF | X86_EFLAGS_BIT1;
 		return 0;
 	}
-	*childregs = *regs;
+	*childregs = *current_pt_regs();
 
 	childregs->ax = 0;
-	childregs->sp = sp;
+	if (sp)
+		childregs->sp = sp;
 
 	err = -ENOMEM;
 	memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));