The patch titled
debug-pagealloc: add support for highmem pages
has been added to the -mm tree. Its filename is
debug-pagealloc-add-support-for-highmem-pages.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: debug-pagealloc: add support for highmem pages
From: Akinobu Mita <akinobu.mita@xxxxxxxxx>
This adds support for highmem pages poisoning and verification to the
debug-pagealloc feature for no-architecture support.
Signed-off-by: Akinobu Mita <akinobu.mita@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/debug-pagealloc.c | 47 ++++++++++++-----------------------------
1 file changed, 14 insertions(+), 33 deletions(-)
diff -puN mm/debug-pagealloc.c~debug-pagealloc-add-support-for-highmem-pages mm/debug-pagealloc.c
--- a/mm/debug-pagealloc.c~debug-pagealloc-add-support-for-highmem-pages
+++ a/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 +21,16 @@ static inline bool page_poison(struct pa
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;
- if (PageHighMem(page)) {
- poison_highpage(page);
- return;
- }
+ preempt_disable();
+ addr = kmap_atomic(page);
set_page_poison(page);
- addr = page_address(page);
memset(addr, PAGE_POISON, PAGE_SIZE);
+ kunmap_atomic(addr);
+ preempt_enable();
}
static void poison_pages(struct page *page, int n)
@@ -86,27 +75,19 @@ static void check_poison_mem(unsigned ch
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);
- }
+ preempt_disable();
+ addr = kmap_atomic(page);
+ check_poison_mem(addr, PAGE_SIZE);
+ clear_page_poison(page);
+ kunmap_atomic(addr);
+ preempt_enable();
}
static void unpoison_pages(struct page *page, int n)
_
Patches currently in -mm which might be from akinobu.mita@xxxxxxxxx are
linux-next.patch
ext4-use-proper-little-endian-bitops.patch
ocfs2-avoid-unaligned-access-to-dqc_bitmap.patch
mm-debug-pageallocc-use-plain-__ratelimit-instead-of-printk_ratelimit.patch
lib-stringc-introduce-memchr_inv.patch
mm-debug-pageallocc-use-memchr_inv.patch
debug-pagealloc-add-support-for-highmem-pages.patch
debug-pagealloc-add-support-for-highmem-pages-fix.patch
--
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