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Commit 64212ec5 authored by Akinobu Mita's avatar Akinobu Mita Committed by Linus Torvalds
Browse files

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: default avatarAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 3ee9a4f0

mm/debug-pagealloc.c

+10 −34
Original line number Diff line number Diff line 
#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);



	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)