Re: [PATCH v5 1/7] mce: fix set_mce_nospec to always unmap the whole page

Christoph Hellwig
2022-02-02T13:21:47Z

> +static inline int set_mce_nospec(unsigned long pfn)
> {
> unsigned long decoy_addr;
> int rc;
> @@ -117,10 +113,7 @@ static inline int set_mce_nospec(unsigned long pfn, bool unmap)
> */
> decoy_addr = (pfn << PAGE_SHIFT) + (PAGE_OFFSET ^ BIT(63));
>
> - if (unmap)
> - rc = set_memory_np(decoy_addr, 1);
> - else
> - rc = set_memory_uc(decoy_addr, 1);
> + rc = set_memory_np(decoy_addr, 1);
> if (rc)
> pr_warn("Could not invalidate pfn=0x%lx from 1:1 map\n", pfn);
> return rc;
> @@ -130,7 +123,7 @@ static inline int set_mce_nospec(unsigned long pfn, bool unmap)
> /* Restore full speculative operation to the pfn. */
> static inline int clear_mce_nospec(unsigned long pfn)
> {
> - return set_memory_wb((unsigned long) pfn_to_kaddr(pfn), 1);
> + return _set_memory_present((unsigned long) pfn_to_kaddr(pfn), 1);
> }

Wouldn't it make more sense to move these helpers out of line rather
than exporting _set_memory_present?

> /*
> - * _set_memory_prot is an internal helper for callers that have been passed
> + * __set_memory_prot is an internal helper for callers that have been passed

This looks unrelated to the patch.