[tip: objtool/core] x86/xen: Make irq_disable() noinstr

tip-bot2 for Peter Zijlstra
2021-09-15T15:49:24Z

The following commit has been merged into the objtool/core branch of tip:

Commit-ID: bf10b01f581231dc9d25a12dcfec272b981745dc
Gitweb: https://git.kernel.org/tip/bf10b01f581231dc9d25a12dcfec272b981745dc
Author: Peter Zijlstra <peterz@infradead.org>
AuthorDate: Thu, 24 Jun 2021 11:41:20 +02:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Wed, 15 Sep 2021 15:51:50 +02:00

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) <peterz@infradead.org>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20210624095148.933869441@infradead.org
---
arch/x86/kernel/paravirt.c | 7 ++++++-
arch/x86/xen/irq.c | 4 ++--
arch/x86/xen/xen-asm.S | 3 +--
3 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index a9b97a9..5a804de 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -263,6 +263,11 @@ static noinstr void pv_native_irq_enable(void)
native_irq_enable();
}

+static noinstr void pv_native_irq_disable(void)
+{
+ native_irq_disable();
+}
+
struct paravirt_patch_template pv_ops = {
/* Cpu ops. */
.cpu.io_delay = native_io_delay,
@@ -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,
diff --git a/arch/x86/xen/irq.c b/arch/x86/xen/irq.c
index 7fb4cf2..f52b60d 100644
--- a/arch/x86/xen/irq.c
+++ b/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)
{
diff --git a/arch/x86/xen/xen-asm.S b/arch/x86/xen/xen-asm.S
index 2225195..220dd96 100644
--- a/arch/x86/xen/xen-asm.S
+++ b/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.