diff --git a/sys/amd64/linux/linux_machdep.c b/sys/amd64/linux/linux_machdep.c
index 6c5b014853fc..434ea0eac07c 100644
--- a/sys/amd64/linux/linux_machdep.c
+++ b/sys/amd64/linux/linux_machdep.c
@@ -78,6 +78,9 @@ __FBSDID("$FreeBSD$");
 #include <vm/vm_kern.h>
 #include <vm/vm_map.h>
 
+#include <x86/ifunc.h>
+#include <x86/sysarch.h>
+
 #include <amd64/linux/linux.h>
 #include <amd64/linux/linux_proto.h>
 #include <compat/linux/linux_emul.h>
@@ -88,8 +91,6 @@ __FBSDID("$FreeBSD$");
 #include <compat/linux/linux_signal.h>
 #include <compat/linux/linux_util.h>
 
-#include <x86/include/sysarch.h>
-
 int
 linux_execve(struct thread *td, struct linux_execve_args *args)
 {
@@ -276,3 +277,48 @@ linux_set_cloned_tls(struct thread *td, void *desc)
 
 	return (0);
 }
+
+int futex_xchgl_nosmap(int oparg, uint32_t *uaddr, int *oldval);
+int futex_xchgl_smap(int oparg, uint32_t *uaddr, int *oldval);
+DEFINE_IFUNC(, int, futex_xchgl, (int, uint32_t *, int *), static)
+{
+
+	return ((cpu_stdext_feature & CPUID_STDEXT_SMAP) != 0 ?
+	    futex_xchgl_smap : futex_xchgl_nosmap);
+}
+
+int futex_addl_nosmap(int oparg, uint32_t *uaddr, int *oldval);
+int futex_addl_smap(int oparg, uint32_t *uaddr, int *oldval);
+DEFINE_IFUNC(, int, futex_addl, (int, uint32_t *, int *), static)
+{
+
+	return ((cpu_stdext_feature & CPUID_STDEXT_SMAP) != 0 ?
+	    futex_addl_smap : futex_addl_nosmap);
+}
+
+int futex_orl_nosmap(int oparg, uint32_t *uaddr, int *oldval);
+int futex_orl_smap(int oparg, uint32_t *uaddr, int *oldval);
+DEFINE_IFUNC(, int, futex_orl, (int, uint32_t *, int *), static)
+{
+
+	return ((cpu_stdext_feature & CPUID_STDEXT_SMAP) != 0 ?
+	    futex_orl_smap : futex_orl_nosmap);
+}
+
+int futex_andl_nosmap(int oparg, uint32_t *uaddr, int *oldval);
+int futex_andl_smap(int oparg, uint32_t *uaddr, int *oldval);
+DEFINE_IFUNC(, int, futex_andl, (int, uint32_t *, int *), static)
+{
+
+	return ((cpu_stdext_feature & CPUID_STDEXT_SMAP) != 0 ?
+	    futex_andl_smap : futex_andl_nosmap);
+}
+
+int futex_xorl_nosmap(int oparg, uint32_t *uaddr, int *oldval);
+int futex_xorl_smap(int oparg, uint32_t *uaddr, int *oldval);
+DEFINE_IFUNC(, int, futex_xorl, (int, uint32_t *, int *), static)
+{
+
+	return ((cpu_stdext_feature & CPUID_STDEXT_SMAP) != 0 ?
+	    futex_xorl_smap : futex_xorl_nosmap);
+}
diff --git a/sys/amd64/linux/linux_support.s b/sys/amd64/linux/linux_support.s
index a9f02160be26..391f76414f22 100644
--- a/sys/amd64/linux/linux_support.s
+++ b/sys/amd64/linux/linux_support.s
@@ -38,7 +38,7 @@ futex_fault:
 	movl	$-EFAULT,%eax
 	ret
 
-ENTRY(futex_xchgl)
+ENTRY(futex_xchgl_nosmap)
 	movq	PCPU(CURPCB),%r8
 	movq	$futex_fault,PCB_ONFAULT(%r8)
 	movq	$VM_MAXUSER_ADDRESS-4,%rax
@@ -49,9 +49,24 @@ ENTRY(futex_xchgl)
 	xorl	%eax,%eax
 	movq	%rax,PCB_ONFAULT(%r8)
 	ret
-END(futex_xchgl)
+END(futex_xchgl_nosmap)
 
-ENTRY(futex_addl)
+ENTRY(futex_xchgl_smap)
+	movq	PCPU(CURPCB),%r8
+	movq	$futex_fault,PCB_ONFAULT(%r8)
+	movq	$VM_MAXUSER_ADDRESS-4,%rax
+	cmpq	%rax,%rsi
+	ja	futex_fault
+	stac
+	xchgl	%edi,(%rsi)
+	clac
+	movl	%edi,(%rdx)
+	xorl	%eax,%eax
+	movq	%rax,PCB_ONFAULT(%r8)
+	ret
+END(futex_xchgl_smap)
+
+ENTRY(futex_addl_nosmap)
 	movq	PCPU(CURPCB),%r8
 	movq	$futex_fault,PCB_ONFAULT(%r8)
 	movq	$VM_MAXUSER_ADDRESS-4,%rax
@@ -65,9 +80,27 @@ ENTRY(futex_addl)
 	xorl	%eax,%eax
 	movq	%rax,PCB_ONFAULT(%r8)
 	ret
-END(futex_addl)
+END(futex_addl_nosmap)
 
-ENTRY(futex_orl)
+ENTRY(futex_addl_smap)
+	movq	PCPU(CURPCB),%r8
+	movq	$futex_fault,PCB_ONFAULT(%r8)
+	movq	$VM_MAXUSER_ADDRESS-4,%rax
+	cmpq	%rax,%rsi
+	ja	futex_fault
+	stac
+#ifdef SMP
+	lock
+#endif
+	xaddl	%edi,(%rsi)
+	clac
+	movl	%edi,(%rdx)
+	xorl	%eax,%eax
+	movq	%rax,PCB_ONFAULT(%r8)
+	ret
+END(futex_addl_smap)
+
+ENTRY(futex_orl_nosmap)
 	movq	PCPU(CURPCB),%r8
 	movq	$futex_fault,PCB_ONFAULT(%r8)
 	movq	$VM_MAXUSER_ADDRESS-4,%rax
@@ -85,9 +118,31 @@ ENTRY(futex_orl)
 	xorl	%eax,%eax
 	movq	%rax,PCB_ONFAULT(%r8)
 	ret
-END(futex_orl)
+END(futex_orl_nosmap)
 
-ENTRY(futex_andl)
+ENTRY(futex_orl_smap)
+	movq	PCPU(CURPCB),%r8
+	movq	$futex_fault,PCB_ONFAULT(%r8)
+	movq	$VM_MAXUSER_ADDRESS-4,%rax
+	cmpq	%rax,%rsi
+	ja	futex_fault
+	movl	(%rsi),%eax
+1:	movl	%eax,%ecx
+	orl	%edi,%ecx
+	stac
+#ifdef SMP
+	lock
+#endif
+	cmpxchgl %ecx,(%rsi)
+	clac
+	jnz	1b
+	movl	%eax,(%rdx)
+	xorl	%eax,%eax
+	movq	%rax,PCB_ONFAULT(%r8)
+	ret
+END(futex_orl_smap)
+
+ENTRY(futex_andl_nosmap)
 	movq	PCPU(CURPCB),%r8
 	movq	$futex_fault,PCB_ONFAULT(%r8)
 	movq	$VM_MAXUSER_ADDRESS-4,%rax
@@ -105,9 +160,31 @@ ENTRY(futex_andl)
 	xorl	%eax,%eax
 	movq	%rax,PCB_ONFAULT(%r8)
 	ret
-END(futex_andl)
+END(futex_andl_nosmap)
 
-ENTRY(futex_xorl)
+ENTRY(futex_andl_smap)
+	movq	PCPU(CURPCB),%r8
+	movq	$futex_fault,PCB_ONFAULT(%r8)
+	movq	$VM_MAXUSER_ADDRESS-4,%rax
+	cmpq	%rax,%rsi
+	ja	futex_fault
+	movl	(%rsi),%eax
+1:	movl	%eax,%ecx
+	andl	%edi,%ecx
+	stac
+#ifdef SMP
+	lock
+#endif
+	cmpxchgl %ecx,(%rsi)
+	clac
+	jnz	1b
+	movl	%eax,(%rdx)
+	xorl	%eax,%eax
+	movq	%rax,PCB_ONFAULT(%r8)
+	ret
+END(futex_andl_smap)
+
+ENTRY(futex_xorl_nosmap)
 	movq	PCPU(CURPCB),%r8
 	movq	$futex_fault,PCB_ONFAULT(%r8)
 	movq	$VM_MAXUSER_ADDRESS-4,%rax
@@ -125,4 +202,26 @@ ENTRY(futex_xorl)
 	xorl	%eax,%eax
 	movq	%rax,PCB_ONFAULT(%r8)
 	ret
-END(futex_xorl)
+END(futex_xorl_nosmap)
+
+ENTRY(futex_xorl_smap)
+	movq	PCPU(CURPCB),%r8
+	movq	$futex_fault,PCB_ONFAULT(%r8)
+	movq	$VM_MAXUSER_ADDRESS-4,%rax
+	cmpq	%rax,%rsi
+	ja	futex_fault
+	movl	(%rsi),%eax
+1:	movl	%eax,%ecx
+	xorl	%edi,%ecx
+	stac
+#ifdef SMP
+	lock
+#endif
+	cmpxchgl %ecx,(%rsi)
+	clac
+	jnz	1b
+	movl	%eax,(%rdx)
+	xorl	%eax,%eax
+	movq	%rax,PCB_ONFAULT(%r8)
+	ret
+END(futex_xorl_smap)
diff --git a/sys/amd64/linux32/linux32_machdep.c b/sys/amd64/linux32/linux32_machdep.c
index ce06be57e9fa..61ecc87dc77c 100644
--- a/sys/amd64/linux32/linux32_machdep.c
+++ b/sys/amd64/linux32/linux32_machdep.c
@@ -58,10 +58,12 @@ __FBSDID("$FreeBSD$");
 #include <sys/wait.h>
 
 #include <machine/frame.h>
+#include <machine/md_var.h>
 #include <machine/pcb.h>
 #include <machine/psl.h>
 #include <machine/segments.h>
 #include <machine/specialreg.h>
+#include <x86/ifunc.h>
 
 #include <vm/pmap.h>
 #include <vm/vm.h>
@@ -822,3 +824,48 @@ linux_set_thread_area(struct thread *td,
 
 	return (0);
 }
+
+int futex_xchgl_nosmap(int oparg, uint32_t *uaddr, int *oldval);
+int futex_xchgl_smap(int oparg, uint32_t *uaddr, int *oldval);
+DEFINE_IFUNC(, int, futex_xchgl, (int, uint32_t *, int *), static)
+{
+
+	return ((cpu_stdext_feature & CPUID_STDEXT_SMAP) != 0 ?
+	    futex_xchgl_smap : futex_xchgl_nosmap);
+}
+
+int futex_addl_nosmap(int oparg, uint32_t *uaddr, int *oldval);
+int futex_addl_smap(int oparg, uint32_t *uaddr, int *oldval);
+DEFINE_IFUNC(, int, futex_addl, (int, uint32_t *, int *), static)
+{
+
+	return ((cpu_stdext_feature & CPUID_STDEXT_SMAP) != 0 ?
+	    futex_addl_smap : futex_addl_nosmap);
+}
+
+int futex_orl_nosmap(int oparg, uint32_t *uaddr, int *oldval);
+int futex_orl_smap(int oparg, uint32_t *uaddr, int *oldval);
+DEFINE_IFUNC(, int, futex_orl, (int, uint32_t *, int *), static)
+{
+
+	return ((cpu_stdext_feature & CPUID_STDEXT_SMAP) != 0 ?
+	    futex_orl_smap : futex_orl_nosmap);
+}
+
+int futex_andl_nosmap(int oparg, uint32_t *uaddr, int *oldval);
+int futex_andl_smap(int oparg, uint32_t *uaddr, int *oldval);
+DEFINE_IFUNC(, int, futex_andl, (int, uint32_t *, int *), static)
+{
+
+	return ((cpu_stdext_feature & CPUID_STDEXT_SMAP) != 0 ?
+	    futex_andl_smap : futex_andl_nosmap);
+}
+
+int futex_xorl_nosmap(int oparg, uint32_t *uaddr, int *oldval);
+int futex_xorl_smap(int oparg, uint32_t *uaddr, int *oldval);
+DEFINE_IFUNC(, int, futex_xorl, (int, uint32_t *, int *), static)
+{
+
+	return ((cpu_stdext_feature & CPUID_STDEXT_SMAP) != 0 ?
+	    futex_xorl_smap : futex_xorl_nosmap);
+}
diff --git a/sys/amd64/linux32/linux32_support.s b/sys/amd64/linux32/linux32_support.s
index bba0d8d5e715..981bba9f5821 100644
--- a/sys/amd64/linux32/linux32_support.s
+++ b/sys/amd64/linux32/linux32_support.s
@@ -38,7 +38,7 @@ futex_fault:
 	movl	$-EFAULT,%eax
 	ret
 
-ENTRY(futex_xchgl)
+ENTRY(futex_xchgl_nosmap)
 	movq	PCPU(CURPCB),%r8
 	movq	$futex_fault,PCB_ONFAULT(%r8)
 	movq	$VM_MAXUSER_ADDRESS-4,%rax
@@ -49,9 +49,24 @@ ENTRY(futex_xchgl)
 	xorl	%eax,%eax
 	movq	%rax,PCB_ONFAULT(%r8)
 	ret
-END(futex_xchgl)
+END(futex_xchgl_nosmap)
 
-ENTRY(futex_addl)
+ENTRY(futex_xchgl_smap)
+	movq	PCPU(CURPCB),%r8
+	movq	$futex_fault,PCB_ONFAULT(%r8)
+	movq	$VM_MAXUSER_ADDRESS-4,%rax
+	cmpq	%rax,%rsi
+	ja	futex_fault
+	stac
+	xchgl	%edi,(%rsi)
+	clac
+	movl	%edi,(%rdx)
+	xorl	%eax,%eax
+	movq	%rax,PCB_ONFAULT(%r8)
+	ret
+END(futex_xchgl_smap)
+
+ENTRY(futex_addl_nosmap)
 	movq	PCPU(CURPCB),%r8
 	movq	$futex_fault,PCB_ONFAULT(%r8)
 	movq	$VM_MAXUSER_ADDRESS-4,%rax
@@ -65,9 +80,27 @@ ENTRY(futex_addl)
 	xorl	%eax,%eax
 	movq	%rax,PCB_ONFAULT(%r8)
 	ret
-END(futex_addl)
+END(futex_addl_nosmap)
 
-ENTRY(futex_orl)
+ENTRY(futex_addl_smap)
+	movq	PCPU(CURPCB),%r8
+	movq	$futex_fault,PCB_ONFAULT(%r8)
+	movq	$VM_MAXUSER_ADDRESS-4,%rax
+	cmpq	%rax,%rsi
+	ja	futex_fault
+	stac
+#ifdef SMP
+	lock
+#endif
+	xaddl	%edi,(%rsi)
+	clac
+	movl	%edi,(%rdx)
+	xorl	%eax,%eax
+	movq	%rax,PCB_ONFAULT(%r8)
+	ret
+END(futex_addl_smap)
+
+ENTRY(futex_orl_nosmap)
 	movq	PCPU(CURPCB),%r8
 	movq	$futex_fault,PCB_ONFAULT(%r8)
 	movq	$VM_MAXUSER_ADDRESS-4,%rax
@@ -85,9 +118,31 @@ ENTRY(futex_orl)
 	xorl	%eax,%eax
 	movq	%rax,PCB_ONFAULT(%r8)
 	ret
-END(futex_orl)
+END(futex_orl_nosmap)
 
-ENTRY(futex_andl)
+ENTRY(futex_orl_smap)
+	movq	PCPU(CURPCB),%r8
+	movq	$futex_fault,PCB_ONFAULT(%r8)
+	movq	$VM_MAXUSER_ADDRESS-4,%rax
+	cmpq	%rax,%rsi
+	ja	futex_fault
+	movl	(%rsi),%eax
+1:	movl	%eax,%ecx
+	orl	%edi,%ecx
+	stac
+#ifdef SMP
+	lock
+#endif
+	cmpxchgl %ecx,(%rsi)
+	clac
+	jnz	1b
+	movl	%eax,(%rdx)
+	xorl	%eax,%eax
+	movq	%rax,PCB_ONFAULT(%r8)
+	ret
+END(futex_orl_smap)
+
+ENTRY(futex_andl_nosmap)
 	movq	PCPU(CURPCB),%r8
 	movq	$futex_fault,PCB_ONFAULT(%r8)
 	movq	$VM_MAXUSER_ADDRESS-4,%rax
@@ -105,9 +160,31 @@ ENTRY(futex_andl)
 	xorl	%eax,%eax
 	movq	%rax,PCB_ONFAULT(%r8)
 	ret
-END(futex_andl)
+END(futex_andl_nosmap)
 
-ENTRY(futex_xorl)
+ENTRY(futex_andl_smap)
+	movq	PCPU(CURPCB),%r8
+	movq	$futex_fault,PCB_ONFAULT(%r8)
+	movq	$VM_MAXUSER_ADDRESS-4,%rax
+	cmpq	%rax,%rsi
+	ja	futex_fault
+	movl	(%rsi),%eax
+1:	movl	%eax,%ecx
+	andl	%edi,%ecx
+	stac
+#ifdef SMP
+	lock
+#endif
+	cmpxchgl %ecx,(%rsi)
+	clac
+	jnz	1b
+	movl	%eax,(%rdx)
+	xorl	%eax,%eax
+	movq	%rax,PCB_ONFAULT(%r8)
+	ret
+END(futex_andl_smap)
+
+ENTRY(futex_xorl_nosmap)
 	movq	PCPU(CURPCB),%r8
 	movq	$futex_fault,PCB_ONFAULT(%r8)
 	movq	$VM_MAXUSER_ADDRESS-4,%rax
@@ -125,4 +202,26 @@ ENTRY(futex_xorl)
 	xorl	%eax,%eax
 	movq	%rax,PCB_ONFAULT(%r8)
 	ret
-END(futex_xorl)
+END(futex_xorl_nosmap)
+
+ENTRY(futex_xorl_smap)
+	movq	PCPU(CURPCB),%r8
+	movq	$futex_fault,PCB_ONFAULT(%r8)
+	movq	$VM_MAXUSER_ADDRESS-4,%rax
+	cmpq	%rax,%rsi
+	ja	futex_fault
+	movl	(%rsi),%eax
+1:	movl	%eax,%ecx
+	xorl	%edi,%ecx
+	stac
+#ifdef SMP
+	lock
+#endif
+	cmpxchgl %ecx,(%rsi)
+	clac
+	jnz	1b
+	movl	%eax,(%rdx)
+	xorl	%eax,%eax
+	movq	%rax,PCB_ONFAULT(%r8)
+	ret
+END(futex_xorl_smap)