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authorAkinobu Mita <akinobu.mita@gmail.com>2011-10-31 17:08:38 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-10-31 17:30:48 -0700
commit64212ec569bfdd094f7a23d9b09862209a983559 (patch)
treeaf9a80c08795e602c5a6401fa3599562c2b6be48
parent3ee9a4f086716d792219c021e8509f91165a4128 (diff)
downloadop-kernel-dev-64212ec569bfdd094f7a23d9b09862209a983559.zip
op-kernel-dev-64212ec569bfdd094f7a23d9b09862209a983559.tar.gz
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>
-rw-r--r--mm/debug-pagealloc.c44
1 files changed, 10 insertions, 34 deletions
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 @@ static inline bool page_poison(struct page *page)
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 @@ static void check_poison_mem(unsigned char *mem, size_t bytes)
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);
+ void *addr;
+
+ if (!page_poison(page))
return;
- }
- if (page_poison(page)) {
- void *addr = page_address(page);
- check_poison_mem(addr, PAGE_SIZE);
- clear_page_poison(page);
- }
+ 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)
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