diff --git a/sys/i386/i386/support.s b/sys/i386/i386/support.s
index 1e970da67ca7..c3ac17314019 100644
--- a/sys/i386/i386/support.s
+++ b/sys/i386/i386/support.s
@@ -1522,6 +1522,12 @@ ENTRY(longjmp)
 bbhead:
 	.long 0
 
+#if defined(SMP) || !defined(_KERNEL)
+#define MPLOCKED        lock ;
+#else
+#define MPLOCKED
+#endif
+
 	.text
 NON_GPROF_ENTRY(__bb_init_func)
 	movl	4(%esp),%eax
@@ -1530,3 +1536,108 @@ NON_GPROF_ENTRY(__bb_init_func)
 	movl	%edx,16(%eax)
 	movl	%eax,bbhead
 	NON_GPROF_RET
+
+/* necessary for linux_futex support */
+	.text
+
+futex_fault:
+	movl	PCPU(CURPCB), %edx
+	movl	$0, PCB_ONFAULT(%edx)
+	movl	$-EFAULT, %eax
+	ret
+
+/* int futex_xchgl(int oparg, caddr_t uaddr, int *oldval); */
+	.globl	futex_xchgl
+futex_xchgl:
+	movl	PCPU(CURPCB), %eax
+	movl	$futex_fault, PCB_ONFAULT(%eax)
+	movl	4(%esp), %eax
+	movl	8(%esp), %edx
+	cmpl    $VM_MAXUSER_ADDRESS,%edx
+	ja     	futex_fault
+
+	MPLOCKED xchgl	%eax, (%edx)
+	movl	0xc(%esp), %edx
+	movl	%eax, (%edx)
+	xorl	%eax, %eax
+
+	movl	PCPU(CURPCB), %edx	
+	movl	$0, PCB_ONFAULT(%edx)
+	ret
+
+/* int futex_addl(int oparg, caddr_t uaddr, int *oldval); */
+	.globl	futex_addl
+futex_addl:
+	movl	PCPU(CURPCB), %eax
+	movl	$futex_fault, PCB_ONFAULT(%eax)
+	movl	4(%esp), %eax
+	movl	8(%esp), %edx
+	cmpl    $VM_MAXUSER_ADDRESS,%edx
+	ja     	futex_fault
+
+	MPLOCKED xaddl	%eax, (%edx)
+	movl	0xc(%esp), %edx
+	movl	%eax, (%edx)
+	xorl	%eax, %eax
+
+	movl	PCPU(CURPCB), %edx
+	movl	$0, PCB_ONFAULT(%edx)
+	ret
+
+/* int futex_orl(int oparg, caddr_t uaddr, int *oldval); */
+	.globl	futex_orl
+futex_orl:
+	movl	PCPU(CURPCB), %eax
+	movl	$futex_fault, PCB_ONFAULT(%eax)
+	movl	4(%esp), %eax
+	movl	8(%esp), %edx
+	cmpl    $VM_MAXUSER_ADDRESS,%edx
+	ja     	futex_fault
+
+	MPLOCKED orl 	%eax, (%edx)
+	movl	0xc(%esp), %edx
+	movl	%eax, (%edx)
+	xorl	%eax, %eax
+
+	movl	PCPU(CURPCB), %edx
+	movl	$0, PCB_ONFAULT(%edx)
+	ret
+
+/* int futex_andnl(int oparg, caddr_t uaddr, int *oldval); */
+	.globl	futex_andnl
+futex_andnl:
+	movl	PCPU(CURPCB), %eax
+	movl	$futex_fault, PCB_ONFAULT(%eax)
+	movl	4(%esp), %eax
+	movl	8(%esp), %edx
+	cmpl    $VM_MAXUSER_ADDRESS,%edx
+	ja     	futex_fault
+
+	notl	(%edx)
+	MPLOCKED andl 	%eax, (%edx)
+	movl	0xc(%esp), %edx
+	movl	%eax, (%edx)
+	xorl	%eax, %eax
+
+	movl	PCPU(CURPCB), %edx
+	movl	$0, PCB_ONFAULT(%edx)
+	ret
+
+/* int futex_xorl(int oparg, caddr_t uaddr, int *oldval); */
+	.globl	futex_xorl
+futex_xorl:
+	movl	PCPU(CURPCB), %eax
+	movl	$futex_fault, PCB_ONFAULT(%eax)
+	movl	4(%esp), %eax
+	movl	8(%esp), %edx
+	cmpl    $VM_MAXUSER_ADDRESS,%edx
+	ja     	futex_fault
+
+	MPLOCKED xorl 	%eax, (%edx)
+	movl	0xc(%esp), %edx
+	movl	%eax, (%edx)
+	xorl	%eax, %eax
+
+	movl	PCPU(CURPCB), %edx
+	movl	$0, PCB_ONFAULT(%edx)
+	ret