From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.bemta8.messagelabs.com (mail6.bemta8.messagelabs.com [216.82.243.55]) by kanga.kvack.org (Postfix) with ESMTP id ED96E6B0169 for ; Thu, 25 Aug 2011 10:12:19 -0400 (EDT) Received: by ewy9 with SMTP id 9so1344300ewy.14 for ; Thu, 25 Aug 2011 07:12:15 -0700 (PDT) From: Akinobu Mita Subject: [PATCH -v2] debug-pagealloc: add support for highmem pages Date: Thu, 25 Aug 2011 23:14:09 +0900 Message-Id: <1314281649-21508-1-git-send-email-akinobu.mita@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org, akpm@linux-foundation.org, linux-mm@kvack.org Cc: Akinobu Mita This adds support for highmem pages poisoning and verification to the debug-pagealloc feature for no-architecture support. Signed-off-by: Akinobu Mita --- * v2 - unify the handling of highmem and no-highmem pages mm/debug-pagealloc.c | 47 ++++++++++++++--------------------------------- 1 files changed, 14 insertions(+), 33 deletions(-) diff --git a/mm/debug-pagealloc.c b/mm/debug-pagealloc.c index 2618933..bda7ed0 100644 --- a/mm/debug-pagealloc.c +++ b/mm/debug-pagealloc.c @@ -1,6 +1,7 @@ #include #include #include +#include #include #include #include @@ -20,28 +21,16 @@ 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; - 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 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); - } + 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) -- 1.7.4.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org