x86/xen: Make irq_disable() noinstr

vmlinux.o: warning: objtool: pv_ops[31]: native_irq_disable
vmlinux.o: warning: objtool: pv_ops[31]: __raw_callee_save_xen_irq_disable
vmlinux.o: warning: objtool: pv_ops[31]: xen_irq_disable_direct
vmlinux.o: warning: objtool: lock_is_held_type()+0x5b: call to pv_ops[31]() leaves .noinstr.text section

Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Juergen Gross <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

Author: Peter Zijlstra

arch/x86/kernel/paravirt.c

@@ -243,6 +243,11 @@ static noinstr void pv_native_irq_enable(void)
 {
 	native_irq_enable();
 }
+
+static noinstr void pv_native_irq_disable(void)
+{
+	native_irq_disable();
+}
 #endif
 
 enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
@@ -306,7 +311,7 @@ struct paravirt_patch_template pv_ops = {
 
 	/* Irq ops. */
 	.irq.save_fl		= __PV_IS_CALLEE_SAVE(native_save_fl),
-	.irq.irq_disable	= __PV_IS_CALLEE_SAVE(native_irq_disable),
+	.irq.irq_disable	= __PV_IS_CALLEE_SAVE(pv_native_irq_disable),
 	.irq.irq_enable		= __PV_IS_CALLEE_SAVE(pv_native_irq_enable),
 	.irq.safe_halt		= native_safe_halt,
 	.irq.halt		= native_halt,

arch/x86/xen/irq.c

@@ -42,7 +42,7 @@ asmlinkage __visible noinstr unsigned long xen_save_fl(void)
 }
 __PV_CALLEE_SAVE_REGS_THUNK(xen_save_fl, ".noinstr.text");
 
-asmlinkage __visible void xen_irq_disable(void)
+asmlinkage __visible noinstr void xen_irq_disable(void)
 {
 	/* There's a one instruction preempt window here.  We need to
 	   make sure we're don't switch CPUs between getting the vcpu
@@ -51,7 +51,7 @@ asmlinkage __visible void xen_irq_disable(void)
 	this_cpu_read(xen_vcpu)->evtchn_upcall_mask = 1;
 	preempt_enable_no_resched();
 }
-PV_CALLEE_SAVE_REGS_THUNK(xen_irq_disable);
+__PV_CALLEE_SAVE_REGS_THUNK(xen_irq_disable, ".noinstr.text");
 
 asmlinkage __visible noinstr void xen_irq_enable(void)
 {

arch/x86/xen/xen-asm.S

@@ -21,6 +21,7 @@
 #include <linux/init.h>
 #include <linux/linkage.h>
 
+.pushsection .noinstr.text, "ax"
 /*
  * Disabling events is simply a matter of making the event mask
  * non-zero.
@@ -30,8 +31,6 @@ SYM_FUNC_START(xen_irq_disable_direct)
 	ret
 SYM_FUNC_END(xen_irq_disable_direct)
 
-.pushsection .noinstr.text, "ax"
-
 /*
  * Force an event check by making a hypercall, but preserve regs
  * before making the call.