debug-pagealloc: add support for highmem pages
This adds support for highmem pages poisoning and verification to the
debug-pagealloc feature for no-architecture support.
[akpm@linux-foundation.org: remove unneeded preempt_disable/enable]
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/debug-pagealloc.c b/mm/debug-pagealloc.c
index 2618933..7cea557 100644
--- a/mm/debug-pagealloc.c
+++ b/mm/debug-pagealloc.c
@@ -1,6 +1,7 @@
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/mm.h>
+#include <linux/highmem.h>
#include <linux/page-debug-flags.h>
#include <linux/poison.h>
#include <linux/ratelimit.h>
@@ -20,28 +21,13 @@
return test_bit(PAGE_DEBUG_FLAG_POISON, &page->debug_flags);
}
-static void poison_highpage(struct page *page)
-{
- /*
- * Page poisoning for highmem pages is not implemented.
- *
- * This can be called from interrupt contexts.
- * So we need to create a new kmap_atomic slot for this
- * application and it will need interrupt protection.
- */
-}
-
static void poison_page(struct page *page)
{
- void *addr;
+ void *addr = kmap_atomic(page);
- if (PageHighMem(page)) {
- poison_highpage(page);
- return;
- }
set_page_poison(page);
- addr = page_address(page);
memset(addr, PAGE_POISON, PAGE_SIZE);
+ kunmap_atomic(addr);
}
static void poison_pages(struct page *page, int n)
@@ -86,27 +72,17 @@
dump_stack();
}
-static void unpoison_highpage(struct page *page)
-{
- /*
- * See comment in poison_highpage().
- * Highmem pages should not be poisoned for now
- */
- BUG_ON(page_poison(page));
-}
-
static void unpoison_page(struct page *page)
{
- if (PageHighMem(page)) {
- unpoison_highpage(page);
- return;
- }
- if (page_poison(page)) {
- void *addr = page_address(page);
+ void *addr;
- check_poison_mem(addr, PAGE_SIZE);
- clear_page_poison(page);
- }
+ if (!page_poison(page))
+ return;
+
+ addr = kmap_atomic(page);
+ check_poison_mem(addr, PAGE_SIZE);
+ clear_page_poison(page);
+ kunmap_atomic(addr);
}
static void unpoison_pages(struct page *page, int n)
