Re: [PATCH] x86/vdso: Change return type to vm_fault_t for fault handlers

From: Souptick Joarder
Date: Mon Jun 25 2018 - 12:15:57 EST


On Mon, Jun 25, 2018 at 9:41 PM, Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote:
> On Mon, Jun 25, 2018 at 8:55 AM Souptick Joarder <jrdr.linux@xxxxxxxxx> wrote:
>>
>> Use new return type vm_fault_t for fault handler. For
>> now, this is just documenting that the function returns
>> a VM_FAULT value rather than an errno. Once all instances
>> are converted, vm_fault_t will become a distinct type.
>
> Whoa there.. Your commit message makes it sound like you're just
> changing the return type, but:
>
>> if (tsc_pg && vclock_was_used(VCLOCK_HVCLOCK))
>> - ret = vm_insert_pfn(vma, vmf->address,
>> + ret = vmf_insert_pfn(vma, vmf->address,
>> vmalloc_to_pfn(tsc_pg));
>> }
>>
>> - if (ret == 0 || ret == -EBUSY)
>> - return VM_FAULT_NOPAGE;
>> -
>> - return VM_FAULT_SIGBUS;
>> + return ret;
>
> You're refactoring the code, too.
>
> Please fix your changelog.


I have mentioned it.

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Ref-> commit 1c8f422059ae ("mm: change return type to vm_fault_t")

Previously vm_insert_pfn() returns err which has to
mapped into VM_FAULT_* type. The new function
vmf_insert_pfn() will replace this inefficiency by
returning VM_FAULT_* type.
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