[PATCH] KVM: arm64: remove incorrect __init annotation

[PATCH] KVM: arm64: remove incorrect __init annotation

[Arnd Bergmann]

From: Arnd Bergmann <arnd@arndb.de>

When hyp_cpu_pm_exit() is not inlined, it causes a link time warning:

WARNING: modpost: vmlinux.o(.text+0x39974): Section mismatch in reference from the function kvm_arch_init() to the function .init.text:hyp_cpu_pm_exit()
The function kvm_arch_init() references
the function __init hyp_cpu_pm_exit().
This is often because kvm_arch_init lacks a __init
annotation or the annotation of hyp_cpu_pm_exit is wrong.

This is not only called at boot time, so remove the annotation
to prevent undefined behavior in case it gets called after being
freed.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/arm64/kvm/arm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 6e637d2b4cfb..71a49eae9ea0 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1574,12 +1574,12 @@ static struct notifier_block hyp_init_cpu_pm_nb = {
 	.notifier_call = hyp_init_cpu_pm_notifier,
 };
 
-static void __init hyp_cpu_pm_init(void)
+static void hyp_cpu_pm_init(void)
 {
 	if (!is_protected_kvm_enabled())
 		cpu_pm_register_notifier(&hyp_init_cpu_pm_nb);
 }
-static void __init hyp_cpu_pm_exit(void)
+static void hyp_cpu_pm_exit(void)
 {
 	if (!is_protected_kvm_enabled())
 		cpu_pm_unregister_notifier(&hyp_init_cpu_pm_nb);
-- 
2.29.2


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Re: [PATCH] KVM: arm64: remove incorrect __init annotation

[Marc Zyngier]

On Sun, 03 Jan 2021 14:00:50 +0000,
Arnd Bergmann <arnd@kernel.org> wrote:
> 
> From: Arnd Bergmann <arnd@arndb.de>
> 
> When hyp_cpu_pm_exit() is not inlined, it causes a link time warning:
> 
> WARNING: modpost: vmlinux.o(.text+0x39974): Section mismatch in reference from the function kvm_arch_init() to the function .init.text:hyp_cpu_pm_exit()
> The function kvm_arch_init() references
> the function __init hyp_cpu_pm_exit().
> This is often because kvm_arch_init lacks a __init
> annotation or the annotation of hyp_cpu_pm_exit is wrong.
> 
> This is not only called at boot time, so remove the annotation
> to prevent undefined behavior in case it gets called after being
> freed.

It *is* only called at boot time (despite these functions being called
from module_init(), KVM cannot be built as a module on arm64).

The annotations are wrong nonetheless.

> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Posted here [1], and queued for the next batch of fixes.

	M.

[1] https://lore.kernel.org/linux-arm-kernel/20201223120854.255347-1-maz@kernel.org

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Re: [PATCH] KVM: arm64: remove incorrect __init annotation

[Arnd Bergmann]

On Sun, Jan 3, 2021 at 5:43 PM Marc Zyngier <maz@kernel.org> wrote:
>
> On Sun, 03 Jan 2021 14:00:50 +0000,
> Arnd Bergmann <arnd@kernel.org> wrote:
> >
> > From: Arnd Bergmann <arnd@arndb.de>
> >
> > When hyp_cpu_pm_exit() is not inlined, it causes a link time warning:
> >
> > WARNING: modpost: vmlinux.o(.text+0x39974): Section mismatch in reference from the function kvm_arch_init() to the function .init.text:hyp_cpu_pm_exit()
> > The function kvm_arch_init() references
> > the function __init hyp_cpu_pm_exit().
> > This is often because kvm_arch_init lacks a __init
> > annotation or the annotation of hyp_cpu_pm_exit is wrong.
> >
> > This is not only called at boot time, so remove the annotation
> > to prevent undefined behavior in case it gets called after being
> > freed.
>
> It *is* only called at boot time (despite these functions being called
> from module_init(), KVM cannot be built as a module on arm64).

Ah, I see where I went wrong: I looked at the callers of kvm_arch_init_vm()
instead of kvm_arch_init().

      Arnd

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