xen: fix scrub_page()

Impact: fix guest kernel crash with CONFIG_XEN_SCRUB_PAGES=y

Jens noticed that scrub_page() has a buggy unmap of the wrong
thing. (virtual address instead of page)

Linus pointed out that the whole scrub_page() code is an unnecessary
reimplementation of clear_highpage() to begin with.

Just use clear_highpage() rather than reimplementing it poorly.

Reported-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Jeremy Fitzhardinge 2008-11-17 09:35:00 -08:00 committed by Ingo Molnar
parent d3c6aa1e69
commit 26a3e99160

View file

@ -122,14 +122,7 @@ static struct timer_list balloon_timer;
static void scrub_page(struct page *page)
{
#ifdef CONFIG_XEN_SCRUB_PAGES
if (PageHighMem(page)) {
void *v = kmap(page);
clear_page(v);
kunmap(v);
} else {
void *v = page_address(page);
clear_page(v);
}
clear_highpage(page);
#endif
}