lkml.org 
[lkml]   [2020]   [Nov]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v3 2/4] PM: hibernate: make direct map manipulations more explicit
On Tue, Nov 03, 2020 at 02:08:16PM +0300, Kirill A. Shutemov wrote:
> On Sun, Nov 01, 2020 at 07:08:13PM +0200, Mike Rapoport wrote:
> > diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
> > index 46b1804c1ddf..054c8cce4236 100644
> > --- a/kernel/power/snapshot.c
> > +++ b/kernel/power/snapshot.c
> > @@ -76,6 +76,32 @@ static inline void hibernate_restore_protect_page(void *page_address) {}
> > static inline void hibernate_restore_unprotect_page(void *page_address) {}
> > #endif /* CONFIG_STRICT_KERNEL_RWX && CONFIG_ARCH_HAS_SET_MEMORY */
> >
> > +static inline void hibernate_map_page(struct page *page, int enable)
> > +{
> > + if (IS_ENABLED(CONFIG_ARCH_HAS_SET_DIRECT_MAP)) {
> > + unsigned long addr = (unsigned long)page_address(page);
> > + int ret;
> > +
> > + /*
> > + * This should not fail because remapping a page here means
> > + * that we only update protection bits in an existing PTE.
> > + * It is still worth to have WARN_ON() here if something
> > + * changes and this will no longer be the case.
> > + */
> > + if (enable)
> > + ret = set_direct_map_default_noflush(page);
> > + else
> > + ret = set_direct_map_invalid_noflush(page);
> > +
> > + if (WARN_ON(ret))
>
> _ONCE?

I've changed it to pr_warn() after David said people enable panic on
warn in production kernels.

> > + return;
> > +
> > + flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
> > + } else {
> > + debug_pagealloc_map_pages(page, 1, enable);
> > + }
> > +}
> > +
> > static int swsusp_page_is_free(struct page *);
> > static void swsusp_set_page_forbidden(struct page *);
> > static void swsusp_unset_page_forbidden(struct page *);
>
> --
> Kirill A. Shutemov

--
Sincerely yours,
Mike.

\
 
 \ /
  Last update: 2020-11-03 13:14    [W:0.107 / U:2.576 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site