diff --git a/sys/amd64/amd64/cpu_switch.S b/sys/amd64/amd64/cpu_switch.S
--- a/sys/amd64/amd64/cpu_switch.S
+++ b/sys/amd64/amd64/cpu_switch.S
@@ -91,14 +91,8 @@
 	jnz	2f
 	testb	$CPUID_STDEXT_FSGSBASE,cpu_stdext_feature(%rip)
 	jz	2f
-	movl	%fs,%eax
-	cmpl	$KUF32SEL,%eax
-	jne	1f
 	rdfsbase %rax
 	movq	%rax,PCB_FSBASE(%r8)
-1:	movl	%gs,%eax
-	cmpl	$KUG32SEL,%eax
-	jne	2f
 	movq	%rdx,%r12
 	movl	$MSR_KGSBASE,%ecx		/* Read user gs base */
 	rdmsr
diff --git a/sys/amd64/amd64/exception.S b/sys/amd64/amd64/exception.S
--- a/sys/amd64/amd64/exception.S
+++ b/sys/amd64/amd64/exception.S
@@ -479,22 +479,14 @@
 	jz	6f			/* already running with kernel GS.base */
 	testb	$CPUID_STDEXT_FSGSBASE,cpu_stdext_feature(%rip)
 	jz	2f
-	cmpw	$KUF32SEL,TF_FS(%rsp)
-	jne	1f
 	rdfsbase %rax
-1:	cmpw	$KUG32SEL,TF_GS(%rsp)
-	jne	2f
 	rdgsbase %rdx
 2:	swapgs
 	lfence
 	movq	PCPU(CURPCB),%rdi
 	testb	$CPUID_STDEXT_FSGSBASE,cpu_stdext_feature(%rip)
 	jz	4f
-	cmpw	$KUF32SEL,TF_FS(%rsp)
-	jne	3f
 	movq	%rax,PCB_FSBASE(%rdi)
-3:	cmpw	$KUG32SEL,TF_GS(%rsp)
-	jne	4f
 	movq	%rdx,PCB_GSBASE(%rdi)
 	orl	$PCB_FULL_IRET,PCB_FLAGS(%rdi)	/* full iret from user #gp */
 4:	call	handle_ibrs_entry
@@ -730,12 +722,8 @@
 	orl	$PCB_FULL_IRET,PCB_FLAGS(%rdi)
 	testb	$CPUID_STDEXT_FSGSBASE,cpu_stdext_feature(%rip)
 	jz	3f
-	cmpw	$KUF32SEL,TF_FS(%rsp)
-	jne	2f
 	rdfsbase %rax
 	movq	%rax,PCB_FSBASE(%rdi)
-2:	cmpw	$KUG32SEL,TF_GS(%rsp)
-	jne	3f
 	movl	$MSR_KGSBASE,%ecx
 	rdmsr
 	shlq	$32,%rdx
@@ -842,12 +830,8 @@
 	orl	$PCB_FULL_IRET,PCB_FLAGS(%rdi)
 	testb	$CPUID_STDEXT_FSGSBASE,cpu_stdext_feature(%rip)
 	jz	3f
-	cmpw	$KUF32SEL,TF_FS(%rsp)
-	jne	2f
 	rdfsbase %rax
 	movq	%rax,PCB_FSBASE(%rdi)
-2:	cmpw	$KUG32SEL,TF_GS(%rsp)
-	jne	3f
 	movl	$MSR_KGSBASE,%ecx
 	rdmsr
 	shlq	$32,%rdx
@@ -1177,8 +1161,6 @@
 	.globl	ld_fs
 ld_fs:
 	movw	%ax,%fs
-	cmpw	$KUF32SEL,%ax
-	jne	1f
 	movl	$MSR_FSBASE,%ecx
 	movl	PCB_FSBASE(%r8),%eax
 	movl	PCB_FSBASE+4(%r8),%edx
@@ -1212,8 +1194,6 @@
 	 * from the previously saved msr read.
 	 */
 	movl	$MSR_KGSBASE,%ecx
-	cmpw	$KUG32SEL,%si
-	jne	1f
 	movl	PCB_GSBASE(%r8),%eax
 	movl	PCB_GSBASE+4(%r8),%edx
 	jmp	ld_gsbase
diff --git a/sys/amd64/amd64/machdep.c b/sys/amd64/amd64/machdep.c
--- a/sys/amd64/amd64/machdep.c
+++ b/sys/amd64/amd64/machdep.c
@@ -1797,10 +1797,8 @@
 	    (pcb->pcb_flags & PCB_FULL_IRET) == 0) {
 		r = intr_disable();
 		if ((pcb->pcb_flags & PCB_FULL_IRET) == 0) {
-			if (rfs() == _ufssel)
-				pcb->pcb_fsbase = rdfsbase();
-			if (rgs() == _ugssel)
-				pcb->pcb_gsbase = rdmsr(MSR_KGSBASE);
+			pcb->pcb_fsbase = rdfsbase();
+			pcb->pcb_gsbase = rdmsr(MSR_KGSBASE);
 		}
 		set_pcb_flags_raw(pcb, flags);
 		intr_restore(r);