[RFC PATCH v2 04/45] arm64: hibernate: Restore DAIF state on error

[Jinjie Ruan]

在 2026/7/28 0:34, Vladimir Murzin 写道:
> Sashiko AI has reported that if swsusp_mte_save_tags() for some reason
> fails we return from swsusp_arch_suspend() with DAIF being masked -
> that is not what we'd expect. Restore the saved DAIF state before
> returning from the error path.
> 
> Fixes: ee11f332af96 ("arm64: mte: Save tags when hibernating")
> Signed-off-by: Vladimir Murzin <vladimir.murzin at arm.com>
> ---
>  arch/arm64/kernel/hibernate.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/kernel/hibernate.c b/arch/arm64/kernel/hibernate.c
> index 1eb1c1074c5b..7bf117427777 100644
> --- a/arch/arm64/kernel/hibernate.c
> +++ b/arch/arm64/kernel/hibernate.c
> @@ -348,8 +348,10 @@ int swsusp_arch_suspend(void)
>  		crash_prepare_suspend();
>  
>  		ret = swsusp_mte_save_tags();
> -		if (ret)
> +		if (ret) {
> +			local_daif_restore(flags);
>  			return ret;
> +		}

We can use a label to reuse the exit path, otherwise LGTM
Reviewed-by: Jinjie Ruan <ruanjinjie at huawei.com>

--- a/arch/arm64/kernel/hibernate.c
+++ b/arch/arm64/kernel/hibernate.c
@@ -349,7 +349,7 @@ int swsusp_arch_suspend(void)

                ret = swsusp_mte_save_tags();
                if (ret)
-                       return ret;
+                       goto restore_daif;

                sleep_cpu = smp_processor_id();
                ret = swsusp_save();
@@ -391,6 +391,7 @@ int swsusp_arch_suspend(void)
                spectre_v4_enable_mitigation(NULL);
        }

+restore_daif:
        local_daif_restore(flags);

        return ret;


>  
>  		sleep_cpu = smp_processor_id();
>  		ret = swsusp_save();