Re: [PATCH 06/13] KVM: monolithic: x86: remove __exit section prefix from machine_unsetup

Paolo Bonzini
2019-11-05T10:16:27Z

On 04/11/19 23:59, Andrea Arcangeli wrote:
> Adjusts the section prefixes of some KVM x86 code function because
> with the monolithic KVM model the section checker can now do a more
> accurate static analysis at build time and it found a potentially
> kernel crashing bug. This also allows to build without
> CONFIG_SECTION_MISMATCH_WARN_ONLY=n.
>
> The __exit removed from machine_unsetup is because
> kvm_arch_hardware_unsetup() is called by kvm_init() which is in the
> __init section. It's not allowed to call a function located in the
> __exit section and dropped during the kernel link from the __init
> section or the kernel will crash if that call is made.
>
> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
> ---
> arch/x86/include/asm/kvm_host.h | 4 ++--
> arch/x86/kvm/svm.c | 2 +-
> arch/x86/kvm/vmx/vmx.c | 2 +-
> 3 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index b36dd3265036..2b03ec80f6d7 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -1004,7 +1004,7 @@ extern int kvm_x86_hardware_enable(void);
> extern void kvm_x86_hardware_disable(void);
> extern __init int kvm_x86_check_processor_compatibility(void);
> extern __init int kvm_x86_hardware_setup(void);
> -extern __exit void kvm_x86_hardware_unsetup(void);
> +extern void kvm_x86_hardware_unsetup(void);
> extern bool kvm_x86_cpu_has_accelerated_tpr(void);
> extern bool kvm_x86_has_emulated_msr(int index);
> extern void kvm_x86_cpuid_update(struct kvm_vcpu *vcpu);
> @@ -1196,7 +1196,7 @@ struct kvm_x86_ops {
> void (*hardware_disable)(void);
> int (*check_processor_compatibility)(void);/* __init */
> int (*hardware_setup)(void); /* __init */
> - void (*hardware_unsetup)(void); /* __exit */
> + void (*hardware_unsetup)(void);
> bool (*cpu_has_accelerated_tpr)(void);
> bool (*has_emulated_msr)(int index);
> void (*cpuid_update)(struct kvm_vcpu *vcpu);
> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> index 1705608246fb..4ce102f6f075 100644
> --- a/arch/x86/kvm/svm.c
> +++ b/arch/x86/kvm/svm.c
> @@ -1412,7 +1412,7 @@ __init int kvm_x86_hardware_setup(void)
> return r;
> }
>
> -__exit void kvm_x86_hardware_unsetup(void)
> +void kvm_x86_hardware_unsetup(void)
> {
> int cpu;
>
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index 9c5f0c67b899..e406707381a4 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -7737,7 +7737,7 @@ __init int kvm_x86_hardware_setup(void)
> return r;
> }
>
> -__exit void kvm_x86_hardware_unsetup(void)
> +void kvm_x86_hardware_unsetup(void)
> {
> if (nested)
> nested_vmx_hardware_unsetup();
>

Queued, thanks.

Paolo