On 02/20/24 at 02:36pm, Kirill A. Shutemov wrote:
> On Tue, Feb 20, 2024 at 06:25:43PM +0800, Baoquan He wrote:
> > > I am not sure what part of the comment you see doesn't reflect the
> > > behaviour. From my PoV, changed code matches the comment closer that
> > > original.
> >
> > Oh, I didn't make it clear. I mean update the code comment for
> > lookup_address(), and add code comment for lookup_address_in_pgd() to
> > mention the level thing. Maybe it's a chance to do that.
> >
> > ===1>
> > *
> > * Lookup the page table entry for a virtual address. Return a pointer
> > * to the entry and the level of the mapping.
> > *
> > * Note: We return pud and pmd either when the entry is marked large
> > ~~~~~~~~~~~ seems we return p4d too
> > * or when the present bit is not set. Otherwise we would return a
> > * pointer to a nonexisting mapping.
> > ~~~~~~~~~~~~~~~ NULL?
> > */
> > pte_t *lookup_address(unsigned long address, unsigned int *level)
> > {
> > return lookup_address_in_pgd(pgd_offset_k(address), address, level);
> > }
> > EXPORT_SYMBOL_GPL(lookup_address);
> > ===
> >
> > ===2>
> > /*
> > * Lookup the page table entry for a virtual address in a specific pgd.
> > * Return a pointer to the entry and the level of the mapping.
> > ~~ also could return NULL if it's none entry. And do we need to
> > mention the level thing?
> > */
> > pte_t *lookup_address_in_pgd(pgd_t *pgd, unsigned long address,
> > unsigned int *level)
> > ...
> > }
> >
>
> What about this fixup:
Some nitpicks.
>
> diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
> index 3612e3167147..425ff6e192e6 100644
> --- a/arch/x86/mm/pat/set_memory.c
> +++ b/arch/x86/mm/pat/set_memory.c
> @@ -657,7 +657,8 @@ static inline pgprot_t verify_rwx(pgprot_t old, pgprot_t new, unsigned long star
>
> /*
> * Lookup the page table entry for a virtual address in a specific pgd.
> - * Return a pointer to the entry and the level of the mapping.
> + * Return a pointer to the entry and the level of the mapping (or NULL if
> + * the entry is none) and level of the entry.
^ this right parenthesis may need be moved to the end.
=======
* Return a pointer to the entry and the level of the mapping (or NULL if
* the entry is none and level of the entry).
=======
> */
> pte_t *lookup_address_in_pgd(pgd_t *pgd, unsigned long address,
> unsigned int *level)
> @@ -704,9 +705,8 @@ pte_t *lookup_address_in_pgd(pgd_t *pgd, unsigned long address,
> * Lookup the page table entry for a virtual address. Return a pointer
> * to the entry and the level of the mapping.
> *
> - * Note: We return pud and pmd either when the entry is marked large
> - * or when the present bit is not set. Otherwise we would return a
> - * pointer to a nonexisting mapping.
> + * Note: the function returns p4d, pud and pmd either when the entry is marked
~~~
^ s/and/or/
> + * large or when the present bit is not set. Otherwise it returns NULL.
> */
> pte_t *lookup_address(unsigned long address, unsigned int *level)
> {
> --
> Kiryl Shutsemau / Kirill A. Shutemov
>
_______________________________________________
kexec mailing list
kexec@xxxxxxxxxxxxxxxxxxx
http://lists.infradead.org/mailman/listinfo/kexec
