Hi!
> SANITIZE_FREED_PAGES feature relies on having all pages going through
> the free_pages_prepare path in order to be cleared before being used. In
> the hibernate use case, pages will automagically appear in the system
> without being cleared.
>
> This patch will make sure free pages are cleared on resume; when we'll
> enable SANITIZE_FREED_PAGES. We free the pages just after resume because
> we can't do it later: going through any device resume code might
> allocate some memory and invalidate the free pages bitmap.
>
> Signed-off-by: Anisse Astier <anisse@xxxxxxxxx>
> ---
> kernel/power/hibernate.c | 7 ++++++-
> kernel/power/power.h | 4 ++++
> kernel/power/snapshot.c | 21 +++++++++++++++++++++
> 3 files changed, 31 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
> index 2329daa..3193b9a 100644
> --- a/kernel/power/hibernate.c
> +++ b/kernel/power/hibernate.c
> @@ -305,9 +305,14 @@ static int create_image(int platform_mode)
> error);
> /* Restore control flow magically appears here */
> restore_processor_state();
> - if (!in_suspend)
> + if (!in_suspend) {
> events_check_enabled = false;
>
> +#ifdef CONFIG_SANITIZE_FREED_PAGES
> + clear_free_pages();
> + printk(KERN_INFO "PM: free pages cleared after restore\n");
> +#endif
> + }
> platform_leave(platform_mode);
>
> Power_up:
Can you move the ifdef and the printk into the clear_free_pages?
This is not performance critical in any way...
Otherwise it looks good to me... if the sanitization is considered
useful. Did it catch some bugs in the past?
Thanks,
Pavel
--
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(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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