Re: 答复: [PATCH] x86/mm, mm/hwpoison: fix unmap kernel 1:1 pages

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, Feb 07, 2022 at 10:03:29AM +0000, 罗飞 wrote:
> >I think he's trying to fix the backport:
> >
> >see 26f8c38bb466c1a2d232d7609fb4bfb4bc121678 which is the stable tree backport:
> >
> >@@ -582,7 +586,8 @@ static int srao_decode_notifier(struct notifier_block *nb, unsigned long val,
> >
> >       if (mce_usable_address(mce) && (mce->severity == MCE_AO_SEVERITY)) {
> >               pfn = mce->addr >> PAGE_SHIFT;
> >-               memory_failure(pfn, MCE_VECTOR, 0);
> >+               if (memory_failure(pfn, MCE_VECTOR, 0))
> >+                       mce_unmap_kpfn(pfn);
>  >       }
> >
> >
> >vs the upstream commit:
> >
> >fd0e786d9d09024f67bd71ec094b110237dc3840
> >
> >@@ -590,7 +594,8 @@ static int srao_decode_notifier(struct notifier_block *nb, unsigned long val,
> >
> >        if (mce_usable_address(mce) && (mce->severity == MCE_AO_SEVERITY)) {
> >               pfn = mce->addr >> PAGE_SHIFT;
> >-               memory_failure(pfn, 0);
> >+               if (!memory_failure(pfn, 0))
> >+                       mce_unmap_kpfn(pfn);
> >       }
> >
> >        return NOTIFY_OK;
> 
> 
> Sorry for my not familiar with submitting patches to stable kernel tree, and here Borislav Petkov said exactly what I meant

Great, can you please resend this and document what this patch is doing
and why it is not in upstream and why is it needed only in this one
branch?

thanks,

greg k-h